New Studies Dispel Health Benefits of Coconut Oil, Favor Olive Oil

The coconut oil craze in the United States has propelled it to the forefront of health and beauty discussion. Not only promoted for its health benefit when consumed, but also its ability to soften skin, thicken hair and whiten teeth – it has become, seemingly, the single most important item in the pantry and medicine cabinet alike.1Healthy and Unhealthy oils

But, emerging new research is casting a different light on the subject.

A new meta-analysis revealed that, in contrast to popular belief, coconut oil is not linked to lower rates of inflammation, glycemia, or adiposity.  It is, in fact, responsible for increasing LDL cholesterol and considered among one of the more dangerous oils when compared to other fats.2

According to Deirdre Mattina, MD, with the Henry Ford Health Systems Women’s Heart Center in Detroit, MI, the confusion has stemmed from widespread claims that coconut oil has anti-inflammatory properties that are based on smaller studies from geographically isolated populations.  Unfortunately, there is relatively little scientific evidence to support the claims.

“A lot of that we sort of took out of context and from what other components are available in those populations’ diets. And then people are just naturally always looking for something that’s marketed as being natural or different in processing, so I think they’re flocking to those things and maybe misinterpreting what healthy really is,” Mattina added.

The study’s senior author, Rob M. van Dam, PhD from the National University of Singapore, told TCTMD, an information resource produced by the Cardiovascular Research Foundation (CRF), that he and his colleagues launched the study because of how widely coconut oil is positively promoted for health benefit in the press.

The study included 16 international trials comparing the effects of at least two weeks of coconut oil consumption with other nontropical vegetable oils or palm oil on cardiovascular risk factors. The trials reported on body weight, body fat, waist circumference, fasting plasma glucose and C-reactive protein.

Findings revealed that when compared with these oils, coconut oil significantly increased total cholesterol, LDL cholesterol, and HDL cholesterol but not triglycerides, body measurements, glycemia, or C-reactive protein.

The authors concluded that ‘the hypercholesterolemic effect of coconut oil intake is probably attributable to its high saturated fat content – consisting of about 90% saturated fat, which is higher than the proportion of saturated fat in butter or lard.’  Additionally, “about a quarter of coconut fat consists of the long-chain saturated fatty acids myristic acid and palmitic acid.”

In an accompanying editorial, Frank Sacks, MD of Harvard TH Chan School of Public Health, Boston, MA, supported the findings and resulting recommendations saying that “coconut oil may be viewed as one of the most deleterious cooking oils that increases risk for cardiovascular disease.3”

The authors further concluded in an article summary that coconut oil holds no benefits with regards to ‘body fatness, inflammation, blood sugar, or heart health – but rather in large quantities can increase blood LDL-cholesterol concentrations, potentially increasing risk of heart disease.’

For van Dam and his colleagues, ongoing research will assess whether consuming coconut oil has any link to cardiovascular disease outcomes, not just markers of disease like serum cholesterol.

Conversely, new observational data shows that higher olive oil intake is associated with a lower risk of coronary heart disease and cardiovascular disease. The study authors note that olive oil consumption, though, is generally less in the US (where saturated fats and other plant-based unsaturated fats play a larger role in the diet) compared with European and Mediterranean populations – consequently less studied in this population group.

Author Marta Guasch-Ferré presented the findings at the American Heart Association’s EPI-Lifestyle 2020 Scientific Sessions, simultaneously publishing in the Journal of the American College of Cardiology.4

Investigators found that subjects consuming more than half a tablespoon per day (>7 g/day) had a 14% lower risk of cardiovascular disease and an 18% lower risk of coronary heart disease over 24 years of follow-up. No link was seen between olive oil consumption and stroke.

Speaking with TCTMD, Guasch-Ferré pointed to additional findings for the US cohort, including important benefits to consumers if olive oil replaced approximately 5 g/day of margarine, butter, mayonnaise, or dairy fat. However, there was no difference between the benefits associated with olive oil consumption and those associated with intake of other nontropical, plant-based oils.

“The main message is that our results provide support for the recommendations to replace saturated fats and animal fat with unsaturated olive oil or other types of unsaturated fats,” said Gausch-Ferré.

When asked about controversies stemming from randomization of subjects in an earlier study on a Mediterranean diet supplemented with additional extra virgin olive oil, reducing major cardiovascular events by 31% compared with a fat restricted control diet (PREDIMED), which Gausch-Ferré co-authored several years earlier, the author underscored the important benefits found in both studies and the need for ongoing research on olive oil consumption.

According to the study summary in TCTMD, the benefits of olive oil may be partly explained by the replacement of saturated fats with unsaturated oil, a recommendation also set out in a recent scientific advisory on dietary cholesterol from the American Heart Association. Though study authors stressed that benefits specific to olive oil itself cannot be discounted, in particular, high oleic acid content, which the authors note is less susceptible to oxidation than other more unsaturated fatty acids.

“It has also been observed that olive oil can have favorable effects on endothelial dysfunction, hypertension, inflammation, insulin sensitivity, and diabetes,” the authors conclude.

The authors were also clear to state the importance in communicating olive oil benefits to the American population, as consumption habits vary greatly from those of the European population.

The benefits intrinsic to olive oil would need to be coupled with moderation and reductions in the types of fats typically consumed in higher quantities by Americans.

We at Carient Heart and Vascular have a robust diet program.  Working collaboratively with our nutrition coaches, we are helping patients change dietary habits to fit their lifestyle and achieve long-term cardiovascular health and well-being.  Learn more about structural heart disease and interventional cardiology. To schedule a consultation, please call 888-602-3339.

Reference

  1. Very Healthy Life. https://veryhealthy.life/11-benefits-coconut-oil/?utm_source=%2Bcoconut%20%2Boil&utm_medium=11BenefitsofCoconutOil&utm_campaign=adw_us .
  2. Neelakantan N, Seah JYH, van Dam RM. The effect of coconut oil consumption on cardiovascular risk factors: a systematic review and meta-analysis of clinical trials. Circulation. 2020;Epub ahead of print.
  3. Sacks FM. Coconut oil and heart health: fact or fiction? Circulation. 2020;Epub ahead of print.
  4. Guasch-Ferré M, Liu G, Li Y, et al. Olive oil consumption and cardiovascular risk in US adultsJ Am Coll Cardiol. 2020;Epub ahead of print.

 

A Closer Look at Mitral Valve Regurgitation

Mitral regurgitation is the most common disease of the mitral valve.

The mitral valve is located between the left atrium and ventricle. It opens during systole, when blood enters the left ventricle from the left atrium, and it closes during ventricular contraction, when blood exits the left ventricle to perfuse the rest of the body.

Unlike the aortic valve, a trileaflet structure that passively opens and closes during the cardiac cycle, the mitral valve is a bileaflet structure with a subvalvular apparatus consisting of cords that connect its leaflets to the papillary muscles. Papillary muscles are part of the left ventricle that help keep the mitral valve closed during ventricular contraction (Figure 1).

The Mitral Valve of the Heart

Figure 1 – The Mitral Valve

Mitral regurgitation is the leakage of blood back into the atrium during left ventricular contraction, resulting from inappropriate closure of the valve leaflets in systole. When regurgitation is mild it is well tolerated and no therapy is needed. However, patients can become symptomatic as the severity of the leakage increases.

Symptoms occur because the increased volume in the left atrium ultimately results in increased pressure in this chamber. This increase in pressure can cause congestion of the lungs resulting in shortness of breath, decrease in exercise tolerance and lower extremity swelling among other symptoms. The increase in volume in the left atrium also causes enlargement of this chamber and can result in cardiac arrhythmias such as atrial fibrillation, which manifest as palpitations – putting the patient at risk for stroke.

Diagnosis of mitral regurgitation starts with the physical exam. Patients usually have a harsh murmur present throughout systole, best heard at the apex. Ultimately, the diagnosis is made on echocardiography. The severity of mitral regurgitation is assessed based on color doppler flow with the use of quantitative measurements, as well as presence or absence of flow reversal in pulmonary veins (Figure2).

Diagnostics for Mitral Valve regurgitation

Figure 2 – Color doppler flow with quantitative measurements to determine severity of Mitral Valve Regurgitation

Generally, pathology of the mitral valve resulting in mitral regurgitation is classified into two separate categories; degenerative and functional.

In degenerative (primary) mitral regurgitation, the pathology involves the mitral valve itself causing malcoaptation of the leaflets. This could be the result of prolapse of one or both leaflets during systole, among other pathologies.

In functional mitral regurgitation, the mitral valve malcoaptation is due to the disease of the left ventricle. For example, patients with advanced congestive heart failure can have dilated left ventricles. This dilation can also stretch the mitral valve annulus and cause malcoaptation of the valve leaflets in systole (Figure3).

Types of Mitral Valve Regurgitation

Figure 3 – Examples of primary and functional mitral valve regurgitation.

Traditionally, surgical repair is shown to be superior to replacement in degenerative mitral regurgitation, while this distinction is not present in functional regurgitation. During repair, the surgeon uses multiple techniques to assure appropriate coaptation of the leaflets during ventricular contraction. Excision of part of the leaflet, suturing part of the leaflets together, and placing a ring along the valve annulus or rearranging the valvular chords are some of these techniques. Mitral valve replacement involves excising the native valve and replacing it with either a bio or mechanical prosthesis.

Over the past decade transcatheter techniques have been developed to mimic surgical ones. In the majority of these techniques, devices are advanced through the femoral vein from the patient’s leg to the mitral valve, avoiding any incisions.

Currently, the most studied and only commercially available transcatheter repair device is MitraClip. By using MitraClip (Figure4), the interventionalist tries to mimic the surgical technique of suturing part of the leaflets together by advancing a clip from the femoral vein and delivering it to the leaflets.

MitraClip

Figure 4 – MitraClip for transcatheter mitral valve therapy.

This delivery would require making a small hole in the intra-atrial septum, enabling the operator to deliver the device from the right side of the heart to the left. In the appropriate patient and in experienced hands, severe mitral regurgitation can be reduced to trace or mild, resulting in improvement of the patient’s symptoms as well as prognosis.  Multiple trials have shown that MitraClip is superior to medical therapy alone in patients with both functional as well as degenerative mitral regurgitation who are at high surgical risk.

While MitraClip is the only commercially available device currently in the US, many other devices are being investigated in different trials. Most of these devices try to duplicate other surgical techniques such as annuloplasty or chordal repair through transcatheter means.

Enthusiasm for transcatheter methods to treat mitral regurgitation is not limited to repair techniques. There is a lot of research focus on replacing the mitral valve without surgery. One area in which this is commercially available is in patients who have already had a mitral valve replacement with a bioprosthesis. Transcatheter methods can be used for therapy, should the initial bioprosthesis degenerate over time. In most cases a new valve can be delivered inside the degenerated one safely – the bioprosthetic valve functioning as the anchor for the new valve (Figure5).

Transcatheter Mitral Valve Repair

Figure 5 – Transcatheter therapy to address degenerative mitral valve bioprosthesis.

Unfortunately, the lack of appropriate anchoring is a major obstacle to replace a native mitral valve with severe regurgitation. The other obstacle is the potential obstruction of the blood flow path out of the heart by native leaflets that can be pushed into the left ventricular outflow track by the new valve. Different methods and devices are being developed and investigated to alleviate these obstacles.

In summary, while the MitraClip has matured into a valuable tool to treat mitral regurgitation in appropriate patients suffering from the condition, other modalities are actively being evaluated in trials for their safety and efficacy. Transcatheter techniques to treat mitral regurgitation are sure to expand as some of these techniques prove both safe and efficacious.

The Structural Heart Team at Carient Heart & Vascular has treated many patients with mitral regurgitation and is involved in a number of trials involving the mitral valve.

Dr. Shawn Yazdani has served as the primary investigator in many of the trials observing transcatheter therapy in patients at high or prohibitive risk for surgical valve replacement. To obtain more information or to schedule a consultation, please call 888-602-3339.

Recent Studies Reveal Early Discharge Advantage following Successful Transfemoral TAVR Procedure

Reduced Hospitalization Proves Particularly Beneficial During COVID-19 Era, though Caution Needed for Certain Patient Groups

Two recent studies observing patients undergoing a transfemoral transcatheter aortic valve replacement (TAVR) procedure have reported shorter hospital stays with no adverse impact on outcomes among study patients – a particular benefit in the COVID-19 era.Transcatheter Aortic Valve Replacement

One study, conducted by researchers from Policlnico-Vittorio Emanuele Hospital, University of Catania, Italy and published in EuroIntervention, found that “discharging patients within 24 hours of a transfemoral TAVR procedure performed without complications appears to be a safe approach,” which could have implications for patient care in the COVID-19 era.1

The researchers reported that “there were no differences in rates of mortality or rehospitalization for heart failure through the first year between patients discharged the next day and those who left the hospital later” – noting that ‘patients with a prior permanent pacemaker implant (PPI) were more likely to receive next-day discharge.’

These results support broader efforts for a “minimalist approach” to post-procedure patient care in centers across the United States and abroad. Propelled by the pandemic, new protocols and best practices may emerge as a silver lining in otherwise challenging times.2

Conversely, a study published as a research letter November 9, 2020, in JACC: Cardiovascular Interventions, and presented at the virtual American Heart Association 2020 Scientific Sessions, reported that pacemaker implantation has risen slightly amid length of stay decline – suggesting that ‘the trend toward earlier discharge following TAVR means that some conduction disturbances are not picked up by physicians during the index stay and patients may develop complications outside the hospital.’3

While the percentage of pacemaker implantation procedures have remained within range, the early discharge of transfemoral TAVR patients changes the timing of implantation and readmission rates, as patients who may have required a pacemaker during their initial hospital stay are released, though later return for the procedure.

According to the study’s senior investigator, Anil Gehi MD of the University of North Carolina, “the need for pacemaker implantation has remained the same—it’s still in that 10% range—but what we saw was that there was a shift in the timing of pacemaker implantation.”

“Because patients are being discharged sooner, rather than getting their pacemaker during that initial hospitalization, more and more of them are having to come back for readmission and then getting their pacemaker,” said Gehi.

While researchers and practitioners agree shortened hospital stays can be beneficial to patient recovery, particularly during a pandemic, identifying high-risk patients for continued monitoring is key in shaping new protocols.

View video on the TAVR procedure.

References

  1. Costa G, Barbanti M, Picci A, et al. Predictors and safety of next-day discharge in patients undergoing transfemoral transcatheter aortic valve implantationEuroIntervention. 2020;16:e494-e501.
  2. Wood DA, Sathananthan J. “Minimalist” transcatheter aortic valve implantation during the COVID-19 pandemic: previously optional but now a necessityEuroIntervention. 2020;16:e451-e452.
  3. Mazzella AJ, Hendrickson MJ, Arora S, et al. Shifting trends in timing of pacemaker implantation after transcatheter aortic valve replacementJ Am Coll Cardiol Intv. 2020;Epub ahead of print.

 

Aortic Stenosis and the Role of Catheter Based Therapies

When Less Invasive TAVR is Preferable in the Treatment of this Serious Heart Condition

Aortic valve disease is one of the most encountered structural abnormalities of the heart.  The aortic valve is a trileaflet structure that separates the left ventricle from the aorta. In systole, during left ventricular contraction, the aortic valve opens between 3 -5 cm2 to allow blood flow.

Aortic valve disease is one of the most encountered structural abnormalities of the heart.  The aortic valve is a trileaflet structure that separates the left ventricle from the aorta. In systole, during left ventricular contraction, the aortic valve opens between 3 -5 cm2 to allow blood flow through the aorta and to the rest of the body.

The most common disease of the aortic valve is aortic stenosis. Aortic stenosis is the result of calcification and narrowing of the aortic valve. As a result, the valve does not open adequately in systole, causing strain and pressure overload on the left ventricle. Aortic stenosis is the result of active inflammation of the valve, which in many ways is similar to atherosclerosis.

Risk factors for developing aortic sclerosis include hypertension, high cholesterol, diabetes and chronic kidney disease. There is perhaps also a genetic predisposition to developing aortic stenosis. Aortic stenosis is more prevalent in the older population. It is mostly diagnosed and treated in patients in their 70’s and 80’s. It is estimated that over six percent of the population in the United States over the age of 70 suffer from aortic stenosis. However, aortic stenosis can present earlier if the patient is born with an abnormal valve such as an unicuspid or bicuspid valve. In these instances, symptoms develop earlier in the fifth and sixth decade of life.Healthy Aortic Valve

Symptoms of aortic stenosis include chest pain, shortness of breath and palpitation. If left untreated, it can ultimately cause congestive heart failure and loss of consciousness – and ultimately sudden cardiac death. The three-year prognosis in aortic stenosis is extremely poor once the patient has developed symptoms.

Diagnosis of aortic stenosis hinges on a physical examination and noninvasive diagnostic cardiac testing such as echocardiography.  Severe aortic stenosis results in a harsh systolic murmur heard best on the left sternal border. The second heart sound is also blunted or absent in this area. Echocardiography shows thickening and calcification of the valve with significantly reduced mobility in systole. The ultimate diagnosis is made by measuring pressure gradient across the aortic valve, utilizing Doppler Wave Echocardiography. A mean gradient of over 40 mmhg, or a valve area of less than 1 cm square, strongly predicts severe aortic stenosis.Aortic Valve Assessment

Treatment of aortic stenosis requires active intervention. Medical therapy alone does not resolve the severe narrowing of the valve. Traditionally, patients have required open heart surgery to replace the narrowed valve with either a bioprosthesis or a mechanical valve. This would require a sternotomy and 4-6 weeks of recovery post operation.

Over the past decade, though, a new technique utilizing transcatheter methods has been shown to be either equivalent or superior to surgical replacement in most patients regardless of their surgical risks. During this procedure commonly known as Transcatheter Aortic Valve Replacement (TAVR), a new valve is advanced from the femoral artery in the groin (in most instances) and placed inside the narrowed valve. There is no surgical incision during TAVR, therefore recovery is much faster.Transcatheter Aortic Valve Replacement

 

Patients undergoing TAVR need elaborate work up prior to their procedure. Aortic valve size needs to be determined prior to the procedure, unlike the traditional procedure when the surgeon decides on valve size during the surgery. While most valves are delivered through the femoral arteries, there are instances where femoral arteries are either too small or diseased to accommodate delivery of the valve. In these instances, alternative access should be utilized to deliver the valve.

A gated CT angiography is essential to address sizing and access before the procedure. Cardiac catheterization is also needed to define patency of the coronary arteries before the procedure. Significant coronary artery disease usually needs to be addressed prior to TAVR. There are currently three commercially available TAVR valves. Which valve to use depends on the anatomical and clinical characteristics of each individual patient for optimal outcome.

Finally, TAVR in lieu of surgical aortic valve replacement (SAVR) is determined on a case by case basis. For example, a patient with extensive multivessel coronary artery disease (CAD), who will need coronary bypass surgery, should also have SAVR at the same time. Some patients with bicuspid aortic valve also have ascending aortic dilatation and will need surgical repair of their aorta, which can be done at the time of SAVR.

Lastly, there are patients who can go either route depending on their circumstances. For example, a younger patient with a small aortic valve might undergo TAVR now. But it is conceivable that their TAVR valve will deteriorate over the next decade or two and they will need another procedure. The small size of the aortic valve might prohibit another TAVR procedure down the line. So, this patient might decide to have a TAVR now and reserve SAVR for a later time, or, alternatively, do the reverse depending on the circumstances. That is why it is important that the treatment recommendation is made after input from every member of the valve team, including an interventional cardiologist as well as a cardiac surgeon.

 

Should Patients With Stable Coronary Artery Disease Undergo Stent Placement?

Should anyone with obstructive coronary artery disease undergo angioplasty and stent placement?

The answer is, of course, no.

Like everything else in medicine, intervening in a disease process is all about risks vs benefits. The immediate risks of the procedure should be weighed against the patient’s gains from that procedure.

In considering invasive coronary intervention, the degree of symptomatic relief as well as preventing future cardiac events should be weighed against the immediate risks of the procedure. Many trials have tried to identify the patient pools where the benefits of an invasive strategy outweigh the risks.

The recently presented ISCHEMIA trial renewed this discussion regarding the utility of coronary interventions in patients with significant disease. In this trial, presented at the last American Heart Association meeting, patients with stable coronary artery disease were randomized to an invasive strategy with coronary angiography and revascularization (either via stent placement or cardiac bypass surgery) vs Optimal Medical Therapy ( OMT).

After a median of 3.3 years, there was no difference in terms of cardiovascular deaths, heart attacks, heart failure or unstable angina admissions as well as resuscitated cardiac arrests. However, quality of life was shown to be more improved in the invasive treatment arm due to better relief of anginal symptoms.

ISCHEMIA, while a landmark trial, is not the only study showing similarity between OMT and revascularization in patients with coronary artery disease. COURAGE and BARI 2D are two such trials published in the past couple of decades showing similar findings.

There were several criticisms of these trials that resulted in the need for ISCHEMIA. For example, both these trials did not include the new generation of stents.

ISCHEMIA Trial

Also, a significant number of patients enrolled had low burden of ischemia (inadequate blood supply to the heart due to the blockage). Patients with low burden of ischemia are thought to derive less benefit from invasive strategy compared to those with higher degree of ischemia.

Additionally, everyone received cardiac catheterization prior to randomization introducing operator bias in the equation. Keeping the treating physicians blind to the patient’s coronary anatomy (obtained by CT angiography in most) prior to randomization, utilizing new stent designs in the invasive arm, and enrolling only patients with moderate or higher degree of ischemia, the ISCHEMIA trial eliminated some of the concerns raised by the earlier studies.

ISCHEMIA confirmed what most interventional cardiologists already believed. In patients with stable coronary artery disease who do not have high risk features such as left main obstructive disease or very poor heart muscle function (these groups were excluded in the ISCHMIA trial), an invasive strategy alleviates symptoms much better than OMT alone, but it does not give superiority in terms of future deaths or heart attacks.

So, do we have all the answers now based on these results? Should we tell our patients that they only get better symptomatic relief via invasive strategy and nothing else?

The majority of the data available points to the validity of this statement but there remains some unanswered questions. For one, did this study use nuclear or echo imaging as the initial work up for most patients? Nuclear perfusion imaging and stress echocardiography while prevalent are hardly the best tests to define the ischemic burden. Perhaps utilizing more sensitive tests such as PET or FFRCT would better identify patients with higher burden of disease and at higher risk.

Also, as of now we know that patients were randomized based on having more than 50% luminal narrowing on CT angiography. As all interventional cardiologists know, there is a big difference between 50% narrowing and 95%. It is unclear how many patients had FFR (hemodynamic assessment of the blockage) performed at the time of revascularization in ISCHEMIA. No one intervenes on a 50% narrowing without functional data.

Studies such as FAME have shown that identifying lesions with hemodynamic significance at the time of the angiography and intervening on them only will provide patients benefit from future events.

The exact severity of coronary artery disease on CTA and its correlation to the stress imaging studies are unknown since investigators were blinded to the CT results. We also don’t know how many patients in the invasive arm had complete revascularization. Lack of complete revascularization (leaving some of the narrowing untreated at the time of the invasive procedure) could explain absence of superior benefit with the invasive arm.

Upcoming release of further data from the trial will shed light on some of these concerns.

In summary, many patients might benefit from coronary intervention and stent placement on top of OMT. However, this benefit comes from symptomatic relief. So far, there is little data to suggest coronary stent placement protects most stable patients (patients with high risk characteristics excluded) from future cardiac events.

Whether to proceed with coronary intervention or continue with OMT should be based on in-depth discussion between the patient and their treating physicians. Severity of patient symptoms, compliance with medications and understanding of the data by the patient are essential in shared decision making.

Additionally, it is essential that the patient’s work up not stop at perfusion nuclear imaging, given patients with high risk anatomical findings on the follow up CTA were excluded from ISCHEMIA. It would be catastrophic to miss a patient with left main disease (about 5% of screened patients in the trial).

Perhaps a more sensitive test to identify patients with high ischemic burden such as PET or FFRCT should be considered upfront rather than myocardial perfusion imaging when available.

Tricuspid Valve Therapies

Tricuspid regurgitation (TR) has generally been ignored in the therapeutic algorithm of patients with heart disease. There are several reasons for that.

Perhaps the most common reason is that almost 90 percent of patients with severe tricuspid regurgitation (TR) have left-sided heart disease such as mitral valve disease or left ventricular systolic dysfunction. In these instances the TR is thought to be a bi-product of the left-sided disease and most therapies are directed at addressing the left-sided disease.

There is also no effective therapy in the treatment of tricuspid regurgitation. As a matter of fact the most prescribed treatment for this disease is a diuretic. This is in part because surgical literature has shown that patients with primary TR who undergo surgical repair/replacement have higher mortality as well as morbidity compared to other valvular therapies. As a result cardiologists are reluctant to recommend corrective surgery in patients with secondary TR unless the patient was undergoing surgery for another cardiac condition at the same time.

However, there has been a paradigm shift over the past few year in our approach to the treatment of severe TR. A major part of this shift is due to the proliferation of transcatheter techniques in the treatment of other valvular heart diseases such as mitral and aortic valve.

It is observed that patients do worse after transcatheter aortic replacement or transcatheter mitral repair if they have concomitant tricuspid regurgitation. This is in line with the data from the surgical literature. As a result, there is an explosion in device development for percutaneous treatment of tricuspid regurgitation to be done either alone or in conjunction with percutaneous treatment of other valvular heart diseases. Many feasibility trials are currently looking at safety of these devices and a few trials are either ongoing or starting to look at their efficacy.

MitraClip developed to treat mitral regurgitation remains also the most prevalent device used to treat TR in the worldwide registry.

 

 

 

 

 

 

 

 

 

 

 

 

 

Nevertheless, the road ahead from diagnosis to treatment of TR is certainly torturous and long and perhaps it will take many years for us to have a clear understanding of when and how to treat this disease entity.

For one, the timing of intervention to give the patient the best prognosis is poorly understood. In most surgical trials, patients had advanced disease at the time of the operation. It is postulated that intervention should be done earlier in the disease course to give patients the best prognosis. However, the exact timing for transcatheter intervention remains a point of discussion.

Currently surgical correction is considered in patients based on the annular diameter of the tricuspid valve. This might not be the best surrogate marker to assess the severity of tricuspid regurgitation effect on the right ventricle. Many other parameters are being investigated to determine the deleterious effects of TR on the right ventricule. Echocardiographic measurements such as right ventricular strain are among such parameters.

Longitudinal follow up of these parameters will make it more clear as to when to intervene in the disease process to obtain the best prognosis.

The other obstacle in the treatment of TR is the tricuspid valve’s anatomy. It is comprised of three unequal very thin leaflets, the anterior leaflet the longest and posterior leaflet the shortest. Its location and thin nature of the leaflets make echocardiographic imaging especially difficult during any transcatheter procedure.

Optimal intraprocedural imaging is essential in successfully treating the valve. The development of intracardiac imaging as part of the percutaneous devices currently being developed should alleviate some of this difficulty.

Finally, the proximity of other cardiac structure to the tricuspid valve should be taken into account while planning for transcatheter intervention. The right coronary artery is positioned to the lateral aspect of the valve and conduction system to the septal portion. Therefore, the risk of right coronary perforation or inducing conduction disturbance during the procedure should be taken into account. Obtaining a cardiac CT and meticulously evaluating the tricuspid valve and its relationship to other cardiac structures is of paramount importance prior to most percutaneous therapies.

Anatomy of the tricuspid valve and its relationship to other cardiac structures.

 

 

 

 

 

 

 

 

 

Tricuspid valve pathology is perhaps the last valvular pathology to be addressed by transcatheter techniques. There are a lot of challenges ahead as outlined above. Perhaps that is why tricuspid intervention is one of the more exciting fields to be involved in at this time. Also, its treatment could be the most rewarding for the patients as well as physicians.

Watch our recent video presentation on Tricuspid Regurgitation.

Mitral Regurgitation and Advancing Catheter Based Treatments – Results from Recent Landmark COAPT Trial

Mitral regurgitation (MR) is the most prevalent valvular heart disease in the United States and the world.

MR occurs due to malcoaptation of the mitral leaflets in systole (period of contraction of the ventricles). As a result, a portion of the left ventricular volume in systole is ejected back into the left atrium instead of the aorta. Patients become symptomatic when this regurgitant volume is severe. Additionally, the increase in volume and pressure in the heart causes remodeling of the left ventricle over time, ultimately ending in heart failure. Patients can also develop cardiac arrhythmias such as atrial fibrillation, which increases their risk for stroke.

There are two main etiologies for mitral regurgitation. The first is disease of the mitral valve apparatus itself. In some patients, leaflets are elongated, valvular cords are diseased, or one of the leaflets is flail. These conditions cause prolapse of the diseased leaflet in atria or leave a gap between the leaflets during systole. The second etiology causes regurgitation, not because the mitral valve is diseased itself but because the mitral valve is affected by the anatomy of the left ventricle. In this condition the left ventricle dilates because of either coronary artery disease (CAD) or other pathology resulting in malcoaptation of the mitral leaflets, which is either due to dilatation of the mitral valve annulus or through tethering of the leaflets in systole.

The first type of mitral valve regurgitation is called degenerative (DMR), the second is called functional (FMR). The natural history of the disease progression and patient prognosis is very different in each type and the effectiveness of the treatment options vary as well.

Surgical valve repair is the gold standard of treatment in DMR. During repair, an experienced mitral valve surgeon uses different techniques to ensure appropriate coaptation of the mitral leaflets in systole, effectively reducing the regurgitant volume to negligible. These patients do very well post repair and their long-term prognosis is excellent, barring any secondary disease of the heart such as left ventricular dysfunction. It is also well documented that these patients do much better with valve repair versus valve replacement.

Surgical valve repair does not have as good a result in patients with FMR. It has been shown that patients with FMR experience a recurrence of their regurgitation over the years, and in these patients mitral valve replacement – during which the mitral valve is excised and a prosthesis is placed – might be the better option.  Regardless, patients with FMR do not fair as well since their prognosis depends on the disease state of the left ventricle.

There has been tremendous interest generated over the past decade among cardiologists and cardiac surgeons regarding the ability to treat MR via catheter-based techniques. MitraClip® is a catheter-based device that clips the two leaflets of the mitral valve together at the site of the pathology. This device has shown to be effective in symptomatic relief among DMR patients at high risk for surgery and has been commercially available in the US for this indication since 2013. However, this represents a very small portion of patients with severe MR, therefore the utilization of MitraClip has been limited.

The results of the recent landmark trial COAPT, though, were recently published in the New England Journal of Medicine (NEJM). In this study investigators randomized patients with FMR to MitraClip versus medical therapy. These are patients who typically do not undergo surgery since their left ventricular function is poor, their risk higher and surgical results less robust than DMR patients.

The results of the COAPT trial were astounding.

Not only did patients do better with MitraClip in terms of hospitalization and symptomatic relief, but their mortality was also significantly improved. Physicians are optimistic that MitraClip will soon be approved for this indication in the US based on the trial.

Edwards Cardioband System

Medtronic Intrepid Valve

The field of transcatheter mitral valve therapies is evolving fast. There are ongoing trials with flexible and semi-rigid devices to mimic surgical annuloplasty via transcatheter techniques. Millipede (Boston Scientific), Cardioband (Edwards), and Carillon (Cardiac Dimensions) are just a few. There is also much activity involving transcatheter mitral valve replacement. Early feasibility trials are ongoing with Intrepid (Medtronic) and Tendyne (Abbott), both of which are delivered by puncturing the tip of the heart. Also, CardiaQ (Edwards) and M3 (Edwards) are two which are delivered via the leg vessels.

The challenge with transcatheter mitral replacement remains how to deliver the valve safely via the leg vessels and through the heart with good anchoring while avoiding obstruction to other areas of the heart such as left ventricular outflow tract.

One thing is certain – we are in the early stages of a big revolution in the treatment of severe mitral regurgitation. There is nothing more satisfying for an interventional cardiologist than to be part of this journey.

 Shawn Yazdani, MD, FACC, FSCAI, is an interventional cardiologist specializing in structural heart care – leading the way in innovative new approaches and advanced cardiovascular treatments. For more information, 888.602.3339 / www.shawnyazdanimd.com.

A Tale of Two Valves: Why Is Surgery Still the Preferred Treatment for Mitral Valve Disease?

Transcatheter aortic valve replacement (TAVR) has become a mainstream treatment for aortic valve stenosis, a disease that affects the heart’s aortic valve.

As the technique has grown in popularity, many patients are wondering whether similar minimally invasive approaches can be used to treat disease in other heart valves. However, each of the heart’s valves has its own unique anatomy and presents its own unique challenges.

TAVR Takes Over

TAVR was initially approved for patients at high risk of experiencing complications from surgical valve replacement. By 2015, a third of patients being treated for aortic valve stenosis underwent TAVR. And in late 2016, the Food and Drug Administration (FDA) approved TAVR for treating patients at moderate surgical risk after clinical trials showed it was safe and effective for them.

Experts predict the number of patients undergoing TAVR will grow significantly in the next five years, overtaking surgical valve replacement as the most common treatment for aortic valve stenosis.

How We Treat Mitral Valve Disease Today

Now patients and healthcare professionals are wondering: Could the same concept be used to repair other heart valves?

There’s great interest in doing so, especially for treating mitral valve disease – a condition that affects far more patients than aortic valve disease. In fact, experts estimate that several billion dollars have already been spent on research and development of transcatheter therapies for mitral valve disease.

Despite all that activity, though, the only device approved for mitral valve disease so far is the MitraClip. This device has been shown to be somewhat effective in treating mitral regurgitation (backward fow of blood into the heart) in patients with severe disease, who aren’t good surgical candidates.

MitraClip has so far been approved only for treatment of degenerative mitral valve disease, a condition that is the result of pathology of mitral valve itself. Only a mi purity of patients with mitral valve disease have degenarative disease. However, the results of Coapt trial recently presented showed that this device could be as effective in functioitral regurgitation a condition that caused malfunctioning of the mitral valve as a result of dilitation of left ventricule.By far the majority of patients with severe mitral regurgitation have functional disease.

The Mitral Valve’s Tricky Anatomy

While Mitraclip has certainly shown promise in treatment of mitral regurgitation, transcatheter mitral therapies are yet to show similar effectiveness in treatment of mitral valve disease as surgery in all comers. Why is it, then, that transcatheter techniques have been so effective for aortic valves but not for mitral valves? The answer lies in the anatomy and location of these two valves:

  • Shape: The aortic valve is a circular apparatus sitting at the end of a tube. The mitral valve, on the other hand, is noncircular saddle shape and sits in the middle of the heart. As a result, it’s influenced by the many different forces that act on the heart.
  • Location: In addition, the mitral valve is located close to the left ventricle outflow tract, an area in which blood flows out of the heart and into the major arteries. Those factors make mitral valve replacement much more challenging.

Unanswered Questions

While there continues to be a lot of enthusiasm for transcatheter mitral valve therapies, we have a long road ahead before these techniques become mainstream. There are many repair or replacement devices that are being studied. We also don’t know yet whether minimally invasive techniques might be more effective for repairing or for replacing the mitral valve. So far, it seems that mitral valve repair techniques are safer but less effective than mitral valve replacements using these catheter-based approaches.

It took a while before TAVR reached prime time – and it only got there after years of development and proof that the technique was as good or better than surgery. New mitral valve therapies must also pass that test before they become established as an alternative to surgery in patients healthy enough for operations.