Isolated mitral valve surgery risk in 77,836 patients from the Society of Thoracic Surgeons database.

BACKGROUND: Understanding the operative outcomes of mitral valve (MV) surgery across the spectrum of predicted risk of mortality (PROM) is necessary to determine the best use of novel percutaneous approaches. METHODS: The Society of Thoracic Surgeons Adult Cardiac Surgery Database was utilized to study isolated MV operations during two time periods: era 1 (2002 to 2006, n = 37,743) and era 2 (2007 to 2010, n = 40,093). In each era, four PROM groups were defined: low risk (PROM 0% to <4%); intermediate risk (PROM 4% to <8%); high risk (PROM 8% to <12%); and extreme risk (PROM ≥ 12%). In each risk group, mortality rates and observed to expected mortality ratios were compared across eras. RESULTS: A total of 63,645 cases (82%) were classified as low risk, 8,032 (10%) as intermediate risk, 2,765 (4%) as high risk, and 3,394 (4%) as extreme risk. Sixty-seven percent of MV repairs (n = 30,488) and 18% of MV replacements (n = 5,749) had a PROM less than 1%. PROM less than 4% was seen for 93% of MV repairs (n = 42,196) and 66% of replacements (n = 21,449). Across the two eras, the MV repair rate increased from 54.8% to 61.8% (p = 0.0017); and a significant reduction in operative mortality was observed in high risk and extreme risk cohorts (p < 0.05). CONCLUSIONS: The frequency with which MV repair for isolated MV disease is performed has increased over time and is associated with very low early mortality. A significant reduction in mortality among patients at highest risk has occurred, and must be considered as patients are evaluated for percutaneous therapies.

Duke Scholars

Author Pamela Susan Douglas Medicine, Cardiology

Author Sean Michael O'Brien Biostatistics & Bioinformatics, Division of Biostatistics

Author J. Matthew Brennan Medicine, Cardiology