Long-term results of surgical treatment of secondary severe mitral regurgitation in patients with end-stage heart failure: Advantage of prosthesis insertion

Abstract

Surgical treatment of secondary mitral regurgitation (SMR) is controversial. To analyse outcome after undersizing annuloplasty (UA) and mitral valve replacement (MVR). Consecutive patients operated on for severe SMR, with left ventricular ejection fraction (LVEF)<40% and refractory CHF, were included. Endpoints were in-hospital mortality, mid-term cardiovascular (CV) mortality, evolution of LV variables and recurrence of mitral regurgitation (MR). 59 patients were included (mean age 65±10 years, preoperative LVEF 36±6%; effective regurgitant orifice [ERO] 41±17 mm2), 41 with ischaemic disease: 12 underwent UA and 47 underwent MVR; only eight had concomitant coronary revascularization. In-hospital mortality was 3.3% (8.3% in UA group; 2.1% in MVR group). Eight-year CV mortality was 39±13% (40±18% in UA group; 27±10% in MVR group). Older age (hazard ratio 1.14, 95% confidence interval 1.07 to 1.22; P<0.001) and LV end-systolic diameter (hazard ratio 1.18, 95% confidence interval 1.09 to 1.27; P<0.001) independently predicted CV mortality. LVEF did not change between the preoperative and follow-up transthoracic echocardiograms in the MVR group (36±6% vs. 35±10%; P=0.6) or the UA group (36±5% vs. 31±12%; P=0.09). Conversely, LV end-diastolic diameter decreased significantly in the MVR group (64±8m to 59±9mm; P=0.002), but not in the UA group (61±7m to 64±10mm; P=0.2). Recurrence of significant MR occurred in 81% of patients in the UA group (mean postoperative ERO 19±6 mm2) versus none in the MVR group. Surgical treatment of SMR can be performed with acceptable operative risk and mid-term survival in severe heart failure, even if there is no indication for revascularization. MVR is associated with significant reverse remodelling, and UA with prohibitive risk of MR recurrence.