Results
Between January 2008 to December 2017, a total of 40 hospitals and 124 surgeons performed 4,970 mitral valve operations for degenerative MR, with 3,405 (68.5%) being repairs.
The repair group tended to be younger, more likely to be male, elective, and associated with increased surgeon and hospital volume. The repair group was less likely to be associated with urgent surgery, infective endocarditis, reduced LVEF, increased NYHA and other comorbidities such as diabetes (See Table 1). On multivariate analyses, hospital and surgeon remained associated with repair after adjustment for other confounders (See Table 2).
Data regarding 30-day mortality was available for 99.9% of patients. The all-cause mortality rate was 1.67% overall and 1.18% for repair and 2.75% for replacement (OR of unadjusted 30-day mortality of repair compared to replacement 0.42, 95%. CI 0.27-0.65, p<0.01). On univariate analysis, the variables associated with 30-day mortality were increased age, pre-operative dialysis, peripheral vascular disease, significant coronary disease, congestive heart failure, increase NYHA Class, moderate or severely impaired left ventricle (EF ≤45%), non-elective status, concomitant major cardiac surgery or CABG, and mitral valve replacement (see Table 3). The median hospital volume (kept continuous due to small numbers) was lower (21.5 per year) for those that died compared to alive at 30-days (24.3 per year), which was no longer significant after adjustment for age and gender (see Table 4).