J. Maxwell Chamberlain Memorial Paper for Adult Cardiac Surgery. Less-invasive Mitral Valve Operations: Trends and Outcomes from the Society of Thoracic Surgeons Adult Cardiac Surgery Database

Background: The purpose of this study was to examine utilization and outcomes of less-invasive mitral valve (LIMV) operations in North America.

Methods: Between 2004 and 2008, 28,143 patients undergoing isolated mitral valve (MV) operations were identified in The Society of Thoracic Surgeons Adult Cardiac Surgical Database (STS ACSD). The LIMV operations were defined as those performed with femoral arterial and venous cannulation.

Results: The LIMV operations increased from 11.9% of MV operations in 2004 to 20.1% in 2008 (p < 0.0001). In 2008, 26% of STS ACSD centers performed at least one LIMV operation, with a median of 3 per year. Patients in the LIMV group were younger and had fewer comorbidities. Median perfusion (135 versus 108 minutes) and cross-clamp times (100 versus 80 minutes, p < 0.0001) were longer in the LIMV group. Mitral valve repair rates were higher in the LIMV group (85% versus 67%, p < 0.0001). Adjusted operative mortality was similar (odds ratio 1.13, 95% confidence interval: 0.84 to 1.51, p = 0.47). Blood transfusion was less common (odds ratio 0.86, 95% confidence interval: 0.76 to 0.97, p < 0.0001) while stroke was more common (OR 1.96, 95% confidence interval: 1.46 to 2.63, p < 0.0001) in the LIMV group.

Conclusions: In selected patients, LIMV operations can be performed with equivalent operative mortality, shorter hospital stay, fewer blood transfusions, and higher rates of MV repair than conventional sternotomy. However, perfusion and cross-clamp times were longer, and the risk of stroke was significantly higher. Beating- or fibrillating-heart LIMV techniques are associated with particularly high risks for perioperative stroke.