Papillary muscle surgery may benefit patients with ischemic mitral regurgitation

CHICAGO — Patients with severe ischemic mitral regurgitation who underwent surgery were more likely to experience favorable left ventricular modeling and mitral valve configuration if their procedure included papillary muscle approximation, according to findings presented at the American College of Cardiology Scientific Session.

According to the study background, guidelines recommend surgery for patients with severe ischemic mitral regurgitation, but there was no evidence from randomized trials as to whether subvalvular repair affects outcomes.

Francesco Nappi, MD, and colleagues randomly assigned 96 patients with severe ischemic mitral regurgitation to undersizing restrictive mitral annuloplasty along or in conjunction with papillary muscle approximation. They simultaneously published their findings in the Journal of the American College of Cardiology.

The primary endpoint was change in left ventricular end diastolic diameter (LVEDD) at 5 years. Secondary endpoints included all-cause mortality, change in echocardiographic parameters, major adverse cardiac and cerebrovascular events and quality of life.

At 5 years, the mean LVEDD in the papillary muscle approximation group was 56.5 mm (mean change from baseline, –5.8 mm) compared with 60.6 mm in the control group (mean change from baseline, –0.2 mm; P < .001), Nappi, from the department of cardiovascular surgery at the Campus Bio-Medico University in Rome, and colleagues reported.

They found no differences in mortality at 5 years (HR = 0.76; 95% CI, 0.35-1.68), nor a difference in cumulative major adverse cardiac and cerebrovascular events at 5 years (HR = 0.66; 95% CI, 0.42-1.04), but they found that between 48 months and 60 months, the risk for major adverse cardiac and cerebrovascular events was much lower in the papillary muscle approximation group (HR = 0.1; 95% CI, 0.02-0.49).

“This finding suggests a long-term protective effect of papillary muscle surgery that, in combination with a stably reduced LVEDD and improved LV function, decreases the cumulative incidence of adverse events,” the researchers wrote in JACC.

There were no differences between the groups in any quality-of-life outcome, Nappi and colleagues wrote.

Among echocardiographic outcomes, papillary muscle approximation was associated with short-term and long-term reduction in tenting height, tenting area and interpapillary distance, as well as reduced recurrence of moderate to severe mitral regurgitation, they found.

They concluded that long-term adverse LV remodeling has been an impediment to successful mitral repair in patients with ischemic mitral regurgitation, but “papillary muscle surgery together with complete myocardial revascularization can address these issues, improving the generally negative outcomes of this procedure.” – by Erik Swain

References :

Nappi F, et al. Featured Clinical Research I. Presented at: American College of Cardiology Scientific Session; April 2-4, 2016; Chicago.

Nappi F, et al. J Am Coll Cardiol. 2016;doi:10.1016/j.jacc.2016.03.478.

Disclosure: The researchers report no relevant financial disclosures.