EHJ: Cards need to bone up on mitral valve regurgitation guidelines

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Guidelines suggest repair rather than replacement should be the first course of action for asymptomatic severe mitral valve regurgitation, but more often it is not. Researchers suggest that cardiologists should become more familiar with the guidelines to ensure proper surgical referral, according to a study in the Aug. 16 edition of the European Heart Journal.

“The recommended treatment for degenerative mitral valve disease is mitral valve reconstruction, as opposed to valve replacement with a bioprosthetic or mechanical valve, because valve repair is associated with improved event free survival,” the authors wrote. “The debate around appropriate timing of intervention for asymptomatic severe mitral valve regurgitation has put additional emphasis on targeted surgeon referral and the need to ensure a very high rate of mitral valve repair, particularly in the non-elderly population."

According to the authors, degenerative mitral valve disease affects 2 percent of the population and deciding how to treat the condition depends on the severity of the regurgitation in addition to how it may affect ventricular function and dimension, systolic flow reversal, secondary pulmonary hypertension or risk of sudden death.

David H. Adams, MD, of the Mount Sinai School of Medicine in New York City, and colleagues performed a review to outline the best practices for treating the condition.

“Controversy exists as to whether early surgical intervention in asymptomatic patients, before the onset of ventricular changes, improves the outcome of patients with chronic severe degenerative mitral valve disease,” the authors wrote. “This debate has put emphasis on the lack of predictability of mitral valve repair, despite broad consensus that this is the procedure of choice for patients undergoing surgical intervention.”

According to the authors, it is essential for cardiologists to be familiar with degenerative disease differentiation, timing of intervention and surgical techniques.

The authors wrote that echocardiography is the optimal diagnostic approach to evaluate patients with mitral valve disease and said that identifying etiology and underlying lesions that can result in mitral valve dysfunction is important for making clinical decisions for treatment.

“Patients with degenerative mitral regurgitation should be differentiated from those with other forms of mitral disease such as rheumatic or functional mitral regurgitation,” the authors wrote.

While the authors said that etiology, in most cases, can be identified by transthoracic echocardiography, using transesophageal echocardiography is more precise and should be used when the transthoracic approach is inadequate.

“Surgical intervention for chronic severe mitral valve regurgitation is usually triggered by the occurrence of symptoms, declining left ventricular (LV) function, significant LV enlargement, or the development of atrial fibrillation or severe pulmonary hypertension,” the authors wrote.

The authors found that previous studies have documented discordance in ‘real world’ surgical referrals for patients who have Class I indication for surgery. For example, Bach et al of the University of Michigan in Ann Arbor, Mich., evaluated the frequency at which adult patients with recorded severe mitral valve regurgitation were denied surgery. The results showed that 53 of the 112 patients assessed were not referred to surgery, but 39 of those 53 patients had one of more indications for an intervention according to the current guidelines.

“Much of the ‘perceived risks’ leading to a denial of referral were incorrectly interpreted by cardiologists or other referring physicians,” the authors wrote. Further educating clinicians on the current guidelines could improve appropriate surgical referrals.

A previous report conducted by Gammie et al found that repair rates for isolated mitral regurgitation rose from 51 percent to 69 percent between January 2000 and December 2007. Additionally, the authors found that reports have shown repair rates in excess of 90 percent at sites skilled to perform mitral valve repair. This suggested “an ongoing ‘gap’ in best practice surgical care of patients with degenerative disease of at least 20 percent, which translates into a significant incidence of unnecessary mitral valve replacement." The authors said that this reinforces the quality guidelines that say clinicians should refer patients for surgery to sites “experienced in performing mitral valve repair.

“Prevailing data suggest many patients with degenerative mitral valve disease do not receive state-of-the-art care,” the authors wrote. The authors said that reluctance from cardiologists to refer patients for mitral valve surgery in a timely fashion could be due to the unawareness of guidelines and a poor understanding of surgical techniques and its results.

Even though there has been much progress in the surgical repair of mitral valves, the authors still say many patients are subject to unnecessary valve replacements.

“There are numerous ‘medical, geo-political and financial barriers’ to such a transparency in surgical referral, but the patient with degenerative mitral valve disease deserves the best possible chance for a repair procedure, which is associated with lower long-term morbidity and mortality compared with valve replacement in a majority of patients,” the authors concluded.