Propensity-matched analysis of outcomes after mitral valve surgery between trainees and consultants (institutional...

We aimed to determine whether early outcomes and long-term survival after mitral valve surgery performed by trainee residents are equivalent in terms of safety and efficacy when compared with consultant surgeons.

Between January 2000 and December 2015, a total of 1742 patients who underwent mitral valve surgery were identified. Of these, 1622 operations were performed by consultants (Group I) and 120 operations were performed by trainees (Group II). A propensity score-matched analysis has been used to minimize selection bias. Early postoperative outcomes were defined as in-hospital mortality, cerebrovascular accident, postoperative requirement of renal replacement therapy, reoperation for bleeding and postoperative length of hospital stay. Long-term outcomes were evaluated using late survival data after discharge.

Before matching, the 2 groups differed significantly in terms of gender and reduced left ventricular ejection fraction, but these differences were solved after matching. Also, Group I included significantly more patients with mitral regurgitation (83% vs 62%; P < 0.01), but after matching, this difference was corrected (62% vs 59%; P = 0.71). Consultant group was associated with a higher in-hospital mortality (6% vs 2%; P = 0.04) in the unmatched population. Moreover, in the unmatched cohort, this group had longer cross-clamp time compared with the trainees group (91 ± 38 vs 89 ± 26 min; P = 0.47) and longer cardiopulmonary bypass time (132 ± 58 vs 121 ± 33 min; P = 0.27); these differences were not statistically significant. There were no significant differences in postoperative dialysis, cerebrovascular accident, reoperation for bleeding and length of hospital stay. Even after matching, no significant differences were found in terms of perioperative complications. The Kaplan-Meier survival curves at 1, 5 and 10 years were similar between the 2 groups.

Mitral valve surgery can be safely performed by trainees and provides similar short- and long-term results compared with consultant surgeons.