Aortic valve replacement: using a statewide cardiac surgical database identifies a procedural volume hinge point

Area of Science:

• Cardiac Surgery
• Health Services Research
• Patient Outcomes

Background:

• Aortic stenosis therapies are expanding, necessitating evaluation of conventional surgical approaches.
• Conventional aortic valve replacement (AVR) and AVR with coronary artery bypass grafting (CABG) outcomes require assessment, especially for high-risk patients.

Purpose of the Study:

• To analyze the relationship between hospital/surgeon volume and outcomes for AVR and AVR/CABG procedures.
• To identify predictors of early mortality and postoperative complications in patients undergoing AVR.

Main Methods:

• Analysis of 6,270 AVR or AVR/CABG procedures in Michigan (2008-2011) using a statewide cardiothoracic surgical database.
• Assessment of hospital and surgeon volume-outcome relationships, including mortality and complication rates.

Main Results:

• Hospital volume was an independent predictor of early mortality; high-volume hospitals (HVH) had lower mortality (2.41%) than low-volume hospitals (LVH, 4.34%).
• HVHs showed improved outcomes for high-risk patients (predicted risk of mortality > 4.7%) and reduced rates of prolonged ventilation, transfusion, pneumonia, and organ failure.
• No significant surgeon-volume outcome relationship was identified.

Conclusions:

• Volume-outcome relationships exist for AVR, primarily driven by hospital procedural volume.
• High-risk patients undergoing AVR benefit most from procedures performed in high-volume hospital settings.
• Findings suggest a review of approaches for high-risk AVR patients, considering system experience and resource availability.