Demographics and Baseline Clinical Profile
Preoperative patient characteristics are detailed in Table 1. Patients who underwent MVR were overall a sicker group of patients; they were older, were more likely to have unstable angina, New York Heart Association (NYHA) class IV symptoms, cardiogenic shock, recent MI, peripheral vascular disease, end-stage renal failure and the need for urgent or emergent surgery. These differences were not unexpected since the patients were not randomized. The decision whether to repair or replace the mitral valve was based at least in part on these characteristics.