Percutaneous Mitral Commissurotomy Shows Long-term Success, Even with Reintervention

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Nearly half of all patients with mitral stenosis who undergo percutaneous mitral commissurotomy (PMC) remain free from cardiovascular death or surgery at 20 years, according to a long-term follow- up study published online March 20, 2013, ahead of print in the European Heart Journal. While reintervention is frequently necessary in these patients, the study found that repeat PMC resulted in equally good outcomes.

Bernard Iung, MD, of Bichat University Hospital (Paris, France), and colleagues studied 912 patients who underwent PMC at their institution from March 1986 to March 1995 and showed good immediate results, defined as a mitral valve area ≥ 1.5 cm² and mitral regurgitation of grades 2 to 4 or less.

At a median follow-up of 12 years, 351 patients (38%) required reintervention. Of these, 24% had repeat PMC and 76% were managed surgically. Surgical interventions consisted of isolated mitral valve surgery (either replacement or repair) in 78% of patients. The remaining 22% underwent combined surgery including aortic valve replacement or CABG.

Age, A-fib Among Factors in Reinterventions

At 20 years, overall survival was 75% with a cardiovascular survival rate of 85%. Cardiovascular survival was 38% for patients without reintervention (either surgery or repeat PMC) at 20 years, while 46% remained free from cardiovascular death and surgery.

In multivariable analysis, older age, male sex, higher NYHA class, A-fib, valve calcification, smaller mitral valve area after PMC, and higher mean gradient after PMC were independent predictors of cardiovascular death or mitral surgery. Additionally, cardiovascular survival without reintervention began to decline significantly at age 50 (28% vs. 45% for age > 50). The same pattern was seen for cardiovascular survival without surgery alone (32% vs. 57% for age > 50).

Among patients who underwent reintervention, those who received repeat PMC compared with mitral surgery were younger, less frequently in A-fib and had less calcified valves (table 1).

Table 1. Comparison of Patient Characteristics by Method of Reintervention

No patient who underwent repeat PMC died as a result of the procedure. The most frequent complication was severe traumatic mitral regurgitation (4%). After repeat PMC, the median valve area increased from 1.1 cm² to 1.9 cm² (P < 0.0001) and median gradient decreased from 10 mm Hg to 4 mm Hg (P < 0.0001).

Repeat PMC Presents Good Option

During a median follow-up of 40 months after repeat PMC, 2 patients died from cardiovascular causes and 27 underwent subsequent reintervention, mainly surgery. Of the 56 patients who survived without further reintervention, 96% were in NYHA class I or II at the last follow-up. After repeat PMC, the 10-year rate of cardiovascular survival was 52% for those not needing any additional reintervention and 60% for those not needing mitral surgery.

According to the authors, the findings attest to the fact that patients who have good immediate results after PMC can expect good long-term outcomes, as well as to the low mortality rate associated with mitral stenosis after reintervention.

They note that when surgery is needed for mitral restenosis after PMC, valve replacement is often performed “due to frequent nonfavorable valve anatomy” and because that is “the favored therapeutic option for most teams.” But given the high rates of cardiovascular survival in the repeat PMC cohort in this study, “PMC may be particularly useful for deferring the need for surgery in young patients” even when anatomy is not ideal.

Delaying Surgery Benefits Patients

“This study reaffirms what we have known about commissurotomy for many years,” Ted Feldman, MD, of Evanston Hospital (Evanston, IL), told TCTMD in a telephone interview.

He explained that the majority of patients who undergo PMC have mitral stenosis stemming from rheumatic valvular disease, which has a low natural prevalence in the United States due to widespread antibiotic therapy for streptococcal infections.

A novel characteristic of individuals with rheumatic disease, he added, is that they tend to be younger. More than half of the patients in the current study were under 50 years of age at the time of their initial procedure. Even at 20-year follow up, they were still under age 70.

“Depending on how long the authors themselves live, we could see quite a bit more follow-up from this group,” Dr. Feldman said. “There will be a lot of survivors left in a decade out of a cohort like this, so it’s very realistic to expect a 30-year report.”

He praised the authors for their follow-up thus far, adding that the strategy of putting off surgery for a decade in the majority of patients is “phenomenal” since PMC seems to increase the length of time before a surgical valve becomes necessary.

“This becomes important with regard to the quality-of-life issue too, because the difference for patients living without the prosthesis is huge,” Dr. Feldman said.

He added that currently up to 20% of patients who undergo a first PMC are candidates for a repeat procedure. While surgical commissurotomy has been shown to last about 7 to 10 years in the average patient, these data demonstrate that PMC has improved on that significantly, he concluded.

Study Details

The median age of patients was 48 years; most were highly symptomatic NYHA class III or IV, and 39% were in A-fib at baseline.

 

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Source:
Bouleti C, Iung B, Himbert D, et al. Reinterventions after percutaneous mitral commissurotomy during long-term follow-up, up to 20 years: The role of repeat percutaneous mitral commissurotomy. Eur Heart J. 2013;Epub ahead of print.

 

 

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