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

Background: Surgical treatment of secondary mitral regurgitation (SMR) is controversial.
Aim: To analyse outcome after undersizing annuloplasty (UA) and mitral valve replacement (MVR).
Methods: 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).
Results: 59 patients were included (mean age 65±10 years, preoperative LVEF 36±6%; effective regurgitant orifice [ERO] 41±17 mm ² ), 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 mm ² ) versus none in the MVR group.
Conclusions: 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.
(Copyright © 2018. Published by Elsevier Masson SAS.)