Straight Dope on Medicine: Fixing Mitral Regurgitation

Author

Scott Ganser
November 27, 2023

Rick Lyon has a mitral valve replacement story.

He opted for repair versus replacement. This is a better option if you can get it. The video explains why.

One thing that I’ve always championed is that people, meaning patients and their family, grow up. It doesn’t help anyone when adults act like infants, and have to have their “feelings” serviced.

Surgeons are NOT touchy-feely people. Nor should they be expected to be. They are there to do a job, to fix the problem.

Their more distant personalities probably help them do what they do.

If you want empathy and sympathy, get a Care Bear or Raggedy Ann, and leave your poor surgeon alone. He doesn’t want your emotional diarrhea. Keep it to yourself.

The focus is to have a good, perfect medical outcome.

If you do manage to lock down Mr. Water Works for a surgeon, you probably got the B cut.

When he screws it up, you can have a joint doctor/patient cry session over what was totally avoidable.

What Is Mitral Regurgitation?

Mitral valve regurgitation is a heart valve condition in which the flaps of the mitral valve do not close properly, causing a backward flow of blood back to the heart.

The flaps of the mitral valve (also called valve leaflets or cusps) control the flow of blood from the left atrium to the left ventricle through the valve. If not closed tightly enough or if the valve’s size and shape are altered, blood may leak in the wrong direction. This leak is also referred to as mitral regurgitation (MR) or mitral valve insufficiency and is the most common form of heart valve disease.[i]

There are two types of mitral valve regurgitation:

· Degenerative mitral regurgitation: This occurs when the mitral valve itself is dysfunctional. The flaps may droop or bulge and do not close tightly.

· Functional mitral regurgitation: Functional mitral regurgitation happens when an issue outside of the valve (such as diseases of the left ventricle) causes the leakage. You may have normal valve flaps and still be diagnosed with functional mitral regurgitation.

Echocardiography is the primary and essential diagnostic test for the diagnosis and assessment of mitral regurgitation (American College of Cardiology/American Heart Association (ACC/AHA) [Class I recommendation]. Transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) provide both qualitative and quantitative analysis.[ii]

Mitral regurgitation is a common yet debilitating condition that leads to increased morbidity and mortality.[iii] A study of 144 patients, found that the 5-year mortality of patients with MR was an impressive 30% compared to 13% of the age-matched control group. The study also determined that patients with functional mitral regurgitation had an overall increase in morbidity and mortality than those with structural MR.[iv] 

· Mitral regurgitation is usually caused by genetic conditions (passed down in your family) or by heart attack. 

· The more blood that leaks backward, the harder your heart has to work to pump out enough blood

· Eventually, your heart has to pump so hard to compensate for the leak that you develop heart failure.

· Doctors can hear a heart murmur through a stethoscope and do echocardiography to diagnose mitral regurgitation

· Mild regurgitation may not cause any symptoms or need treatment

· Severe regurgitation can cause symptoms, such as shortness of breath, or an abnormal heart rhythm, such as atrial fibrillation.

· For severe regurgitation, your mitral valve will need to be repaired or replaced[v]

 

Mitral Valve Regurgitation Symptoms

Mitral valve regurgitation often evolves slowly with no noticeable symptoms. As the condition progresses, you may develop heart valve disease symptoms including:

· Shortness of breath: You may have trouble breathing, especially during exercise.

· Heart palpitations: You may notice a fluttering sensation in your heart, especially when lying on your left side.

· Swelling of hands and feet: Extremities may swell when blood flow is disturbed.

· Fatigue: You may tire easily, especially during physical exertion.

Long-awaited outcomes data of transcatheter edge-to-edge procedures to repair patients’ leaky mitral valves revealed the minimally invasive procedure to be safe and effective in nearly 90% of patients, according to Cedars-Sinai physician-scientists.

Their findings on the condition called degenerative mitral regurgitation were published today in the peer-reviewed Journal of the American Medical Association (JAMA), representing the largest study to date that examines outcomes for patients treated outside of a clinical trial with transcatheter edge-to-edge repair (TEER).

“Treatment was successful in nearly nine out of every 10 patients in whom TEER was used to repair their mitral valve,” said Raj Makkar, MD, Cedars-Sinai’s vice president of Cardiovascular Innovation and Intervention, the Stephen R. Corday, MD, Chair in Interventional Cardiology and the study’s senior author. “These strong safety and efficacy outcomes were validated, despite the advanced age and significant comorbidities of these patients.” 

Degenerative mitral regurgitation occurs when the mitral valve—one of the heart’s four valves—becomes leaky. While a very small amount of leakiness is common, some people have severe mitral valve regurgitation that can cause blood to leak back through the valve, which can cause fluid buildup in the lungs, with shortness of breath and limited ability to exercise. When this occurs, intervention is required.

Using data from the Transcatheter Valve Therapy (TVT) Registry—a jointly maintained database from the Society for Thoracic Surgery and the American College of Cardiology—investigators analyzed 19,088 patients who underwent TEER for moderate to severe isolated degenerative mitral valve regurgitation between January 2014 and June 2022.

The study’s primary endpoint was mitral regurgitation success, defined by investigators as moderate or better residual mitral regurgitation without narrowing of the mitral valve. Additional endpoints included death while hospitalized and within 30 days and within one year of the procedure.

Key findings include:

  • Patients’ average age was 82.

  • 49% were women.

  • Mitral regurgitation success was shown in 88.9% of patients. 

  • At 30 days, the incidence of death was 2.7%, stroke was 1.2% and mitral valve reintervention was 0.97%.

  • The lowest mortality rate was observed in patients who had both mild or less residual mitral regurgitation.

To treat mitral valve regurgitation—a condition affecting more than 2 million Americans—experts from the Smidt Heart Institute

Joanna Chikwe, MD

at Cedars-Sinai rely on either the minimally invasive TEER procedure, minimally invasive robotic surgery or minimally invasive surgery. All patients treated at Cedars-Sinai meet with an interventional cardiologist as well as a cardiac surgeon before making their treatment decision.

Edwards Life Sciences also has something positive to say, regarding their CLASP IID.

Patients enrolled in the CLASP IID pivotal trial had significant symptomatic DMR and were determined to be at prohibitive surgical risk. Patients enrolled in the CLASP IID registry met those same criteria yet were deemed ineligible for randomization. One-year results from the CLASP IID randomized trial showed the PASCAL system achieved:

  • Freedom from major adverse events rate of 84.7 percent at one year, and

  • Significant and sustained MR reduction, with 95.8 percent of patients achieving MR ≤2+ at one year.

Increasingly, the MR reduction goal with TEER is to achieve MR ≤1+ because contemporary evidence suggests reduced regurgitation may correlate with improved long-term patient outcomes. At one year, 77.1 percent of PASCAL patients in the trial achieved a MR rate of ≤1+. The PASCAL system also showed sustained outcomes of high survival, low heart failure hospitalization and meaningful quality-of-life improvements.[vi]

Conclusion

The medical good news keeps rolling along, like Old Man River.


[iii] Dziadzko V, Clavel MA, Dziadzko M, Medina-Inojosa JR, Michelena H, Maalouf J, Nkomo V, Thapa P, Enriquez-Sarano M. Outcome and undertreatment of mitral regurgitation: a community cohort study. Lancet. 2018 Mar 10;391(10124):960-969.

[iv] Lindmark K, Söderberg S, Teien D, Näslund U. Long-term follow-up of mitral valve regurgitation--importance of mitral valve pathology and left ventricular function on survival. Int J Cardiol. 2009 Oct 02;137(2):145-50.