Does moderate mitral regurgitation impact early or mid-term clinical outcome in patients undergoing isolated aortic valve replacement for aortic stenosis?
Objective: The early and mid-term impact of functional mitral regurgitation (MR) in patients undergoing isolated aortic valve replacement (AVR) for aortic stenosis remains unresolved. Method: Through our institutional databank, using a case-match study, we identified 58 patients with MR grades 0–1 and 58 patients with MR grades 2–3 (patients matched for sex, age, ejection fraction (EF), NYHA, diabetes, and CVA). Data were collected prospectively (mean duration of follow-up: 3.2±2.4 years). Results: Perioperative morbidity (re-operation for bleeding, low cardiac output, CVA, renal failure) was comparable among groups. Difference in mortality between the two groups was non-significant (7.0 vs. 3.5%, P=0.67 in groups MR 2–3 vs. 0–1, respectively). At early echocardiographic follow-up, 7/58 patients (12.1%) within group MR grades 0–1 increased their MR to grades 2–3; among which only two remained with MR grades 2–3 at mid-term follow-up. Within MR group 2–3, 18/58 (31.0%) remained with MR grades 2–3 among which 7/18 (38.9%) decreased of at least one grade at follow-up. Eight year actuarial survival was comparable in both groups: MR grades 0–1=60.9% vs. MR grades 2–3=55.0%; P=0.1. Actuarial survival of patients with MR grades 2–3 postoperatively was similar to patients with MR grades 0–1 (MR grades 0–1=59.0%, MR grades 2–3=58.9%, P=NS). Conclusions: Presence of preoperative moderate functional MR (grades 2–3) in patients undergoing isolated AVR for aortic stenosis regresses in the majority of patients postoperatively and has no significant impact on perioperative morbidity or mortality, nor mid-term survival. Thus, moderate functional MR should be treated conservatively in the majority of patients especially in the elderly subjected to isolated AVR for aortic stenosis.