Background Optimal timing of surgery in degenerative mitral regurgitation (MR) remains a controversial topic. The impact of current ACC/AHA guideline recommendations about optimal timing of surgery on outcomes is untested and contemporary data are lacking.

Objective To assess the association between the timing of surgery and long-term survival in patients with severe MR.

Methods A cohort of 481 patients with severe, degenerative mitral regurgitation (1995–2007) from the Duke Cardiovascular Disease Databank who fulfilled at least one ACC/AHA guideline indication for surgery was identified. Exclusion criteria were rheumatic disease, congenital mitral valve (MV) disease, hypertrophic cardiomyopathy, coronary disease in more than one vessel, endocarditis, other severe valve disease, h/o valve repair/replacement. Patients were grouped into early surgery (in ≤2 months of presenting with surgical indications) and late surgery (>2 months) groups. An adjusted Cox regression model was constructed for time to death after 2 months with a time-dependent covariate term for late surgery.

Results 168 patients had early surgery (median time to surgery 0.42 months) with 153 followed up after 2 months, 94 had late surgery (median time to surgery 8.75 months) and 219 medically managed. 127/168 in the early surgery group and 84/94 in the late surgery group received MV repair (p=0.02). Over 5.6 years' (median) follow-up there were 35 deaths (21%) in the early surgery group, with two occurring before 2 months and 20 (21%) in the late group. In the multivariable model, those undergoing early surgery had a lower hazard for death than those who underwent late surgery (HR=0.54 (95% CI 0.30 to 0.97), p=0.039). MV repair was independently associated with survival (HR=0.45 (95% CI 0.25 to 0.83), p=0.01).

Conclusions In patients with severe MR who presented with guideline indications for surgery, those selected for earlier surgery had improved survival. These data support the current guidelines for early referral to surgery in patients with severe MR for enlarged left ventricular dimensions, reduced ejection fraction and symptoms rather than delaying surgery. Larger randomised trials are needed to definitively answer the question of optimal timing of surgery in patients with severe degenerative MR.