Mitral valve repair rates in degenerative mitral valve disease correlate
with surgeon and hospital procedural volume
Abstract
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 centres. Methods: 4,970 patients who underwent surgery for
degenerative MR between January 2008 and December 2017 in the Australian
and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS)
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 56.7% to 80.4% for lowest to highest
volume surgeons; and from 52.0% to 76.1% 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 (OR 2.91,
95% Confidence Interval [CI] 1.50-5.64, p=0.002), particularly if
performing >20/annum (OR 3.9, 95% CI 1.62-9.37, p=0.002).
Compared to hospitals performing ≤10/annum, those performing any number
of procedures >10 demonstrated increased likelihood of
repair (caseload 10.1-20/year OR 2.04, 95% CI 1.30-3.20, p=0.002)
though odds did not increase above this threshold. Low incidence of
30-day mortality (83 of 4,964, 1.67%) limited analysis of contributing
variables; procedural volume did not confer a survival benefit, though
mortality rates were lowest for highest volume proceduralists and
hospitals. 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 utilised to
maximise repair rates, and ideally of 20 for surgeons. Mortality was low
and may not be significantly impacted by procedural volume.