Mitral valve surgery with or without coronary bypass grafting: eight-year cohort study.

Aims: A significant minority of patients undergoing mitral valve surgery (MVR) have indication for coronary artery bypass grafting (CABG). The risks of combination surgeries are not well appreciated and maybe more than additive. We compared the characteristics and outcomes of MVR+/-CABG performed at our centre.

Methods: Consecutive patients undergoing isolated MVR or with concurrent (MVR+)CABG at Auckland City Hospital during 2005-2012 were compared for baseline and operative characteristics and outcomes in univariable and multivariable analyses.

Results: A total of 178 MVR+CABG and 407 MVR patients were included. MVR+CABG patients had higher age, CCS and NYHA Class, cardiopulmonary bypass time, and higher prevalence of urgent surgery, hypertension, diabetes, renal impairment, myocardial infarction/coronary artery disease, congestive heart failure/impaired ejection fraction and peripheral vascular disease, although lower prevalence of active endocarditis and previous valve surgery (all P<0.05). MVR+CABG had higher mortality (operative 11.2% vs 2.5% P<0.001; one and five-year survival 85% vs 96% and 78% vs 87% P=0.041) and composite morbidity 53.4% vs 18.9% P<0.001, including acute renal failure, prolonged ventilation, return to theatre (all P<0.001) but not stroke. In multivariable analyses, MVR+CABG was independently associated with higher operative mortality odds ratio 2.07 95% confidence interval 1.09-3.93 and composite morbidity 2.38 (1.03-5.47), but not long-term mortality.

Conclusion: MVR+CABG compared to MVR patients had more comorbidities and greater operative risk, and were independently associated with higher operative mortality and composite morbidity, but not independently associated with higher long-term mortality.