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Percutaneous mitral commissurotomy (PMC) is safe and effective for patients with mitral valve stenosis even in the presence of significant commissural calcification, according to a study published online January 6, 2014, ahead of print in the European Heart Journal. The results support the use of the procedure as a first-line treatment for this patient group, investigators say.

David Messika-Zeitoun, MD, PhD, of Bichat Hospital (Paris, France), and colleagues studied the impact of valvular calcification on outcomes after PMC in 464 consecutive patients at a single center. The patients were divided into 3 groups based on calcification:

• Cohort 1: no leaflets’ or commissural calcification (n = 261)
• Cohort 2: leaflet calcification with no significant commissural calcification (n = 141)
• Cohort 3: At least 1 significantly calcified commissure (n = 62).

Though final valve area and the rate of complete opening of at least 1 commissure differed between the groups, the rate of severe postprocedural mitral regurgitation was similar (table 1).

Table 1. Outcomes After Percutaneous Mitral Commissurotomy by Level of Calcification

The rate of “good immediate result”, defined as a valve area ≥ 1.5 cm² with no mitral regurgitation > 2, was different between the groups (88%, 78%, and 73%, respectively; P for trend = 0.004).

There were no instances of in-hospital complications, including mortality, in any group, with very low rates of embolism (n = 1 in cohort 1) and tamponade (n = 1 in cohort 2). Mitral valve replacement was required in 7, 3, and 1 patients in the 3 groups, respectively (P for trend = 0.17).

Perfect Valves Not Necessary for PMC

Dr. Messika-Seitoun and colleagues conclude that PMC can be performed even in the presence of commissural calcification. “[Unilateral] commissural calcifications should not be considered as a contra-indication to PMC,” they write, adding that the results reinforce the current guidelines listing PMC as first-line therapy.

The European Society of Cardiology, as well as the American College of Cardiology, list PMC as reasonable for patients with stenosis and moderate calcification, though the recommendation is listed as class IIa. The authors did note the lack of longer-term data, but point out that immediate results are strongly predictive of later outcomes in other studies.

In a telephone interview with TCTMD, Ted Feldman, MD, of Evanston Hospital (Evanston, IL), said that historically many physicians have focused on the Wilkins score for valve morphology to determine whether PMC is indicated. “From the beginning of the procedure, it has been clear that the more deformed the valve, the less good the outcomes,” he commented. “And that has led to an oversimplification in the minds of many cardiologists that a high score, which is defined as a Wilkins score greater than 8, is a contraindication to the procedure.”

Dr. Feldman observed that the paper reinforces 2 main points: that PMC produces generally good results even in calcified valves, and that clinical decision making beyond a simple score is important in patients with mitral valve stenosis. “The score characterizes the valve deformity morphologically, but there are many other factors, including associated valve lesions and the goals for the individual patient,” he said.

PMC is not particularly common in Western Europe and the United States, Dr. Feldman reported, though it remains an “everyday procedure” in countries such as India, Thailand, and others where prophylaxis for strep throat and rheumatic fever are harder to obtain. PMC is among the best-studied valve procedures, and randomized trials have shown similar or better results for balloon procedures compared with surgery, he added.

“There is no indication for surgery in a patient with a well-suited valve for balloon commissurotomy,” Dr. Feldman concluded. The new study extends the category of ‘well-suited’ to those with significant calcification.

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