Mitral valve repair rates in degenerative mitral valve disease correlate with surgeon and hospital procedural volume.

Study Aim: To determine the relationship between surgeon and hospital procedural volume, and mitral valve repair rates and 30-day mortality for degenerative mitral regurgitation (MR), in Australian cardiac surgical centers.

Methods: A total of 4420 patients who underwent elective surgery for degenerative MR between January 2008 and December 2017 in the Australian and New Zealand Society of Cardiac and Thoracic Surgeons Database were retrospectively included. Univariate and multivariate regression analyses examined surgeon and hospital procedural volumes for associations with repair rate and mortality.

Results: Repair rates varied widely by caseload; from 62.57% to 79.53% for lowest to highest volume surgeons; and from 54.56% to 77.54% for lowest to highest volume hospitals. Compared to surgeons performing ≤5 procedures/annum, surgeons performing 10.1-20/annum were more likely to repair the valve (odds ratio [OR] 2.40, 95% confidence interval [CI] 1.09-5.28, p = .03), particularly if performing more than 20/annum (OR 2.88, 95% CI 1.09-7.60, p = .03). Compared to hospitals performing ≤10/annum, those performing any number of procedures more than 10 demonstrated an increased likelihood of repair (caseload 10.1-20/year OR 1.96, 95% CI 1.25-3.07, p = .003) though odds did not increase above this threshold. Low incidence of 30-day mortality (63 of 4414, 1.43%) limited analysis of contributing variables; procedural volume did not confer a survival benefit.

Conclusions: Surgeon and hospital caseload were significantly associated with repair rates of degenerative MR. A threshold minimum of 10 procedures annually for surgeons and hospitals should be utilized to maximize repair rates, and ideally of 20 for surgeons. Mortality was low and may not be significantly impacted by procedural volume.