Surgeon experience and outcomes: specific, analogy-based and cumulative learning in cardiac surgery

OBJECTIVES: To assess how different learning mechanisms, including specific learning, analogy-based learning, and cumulative experience, influence surgical outcomes following coronary artery bypass graft (CABG), aortic valve replacement (AVR), and mitral valve reconstruction (MVR) surgeries. METHODS: Between 2010 and 2023, 46 surgeons performed 21,269 cardiac surgeries (CABG, AVR, and MVR) at a major heart surgery center in Germany. Surgical proficiency was assessed using 30-day risk-adjusted mortality rate (RAMR) and risk-adjusted re-thoracotomy rate (RARR), calculated for each surgeon and adjusted using EuroSCORE II. Linear regression models examined associations between learning mechanisms and surgical outcomes. RESULTS: Higher procedure-specific volume in the preceding quarter was significantly associated with a lower 30-day RAMR for CABG, demonstrating a decline of 0.49 percentage points (95% CI, -0.88 to -0.10; P = 0.014). Furthermore, analogy-based learning demonstrated a significant cross-procedural effect for CABG, as prior-quarter volumes of technically related procedures (AVR and MVR) exhibited significant non-linear associations with 30-day RAMR. For MVR, greater cumulative experience significantly reduced the RARR (-0.295; 95% CI, -0.55 to -0.03; P = 0.028). No significant volume-outcome associations were observed for AVR.This analysis included 21,269 total procedures (12,706 CABG, 5,477 AVR, and 3,086 MVR) from 2010 to 2023. Surgeons had a mean specialist experience of 8.2 years (CABG), 10.3 years (AVR), and 11.9 years (MVR) and performed a mean of 12, 5.1, and 5.1 procedure-specific surgeries per quarter, respectively. CONCLUSIONS: Maintaining consistent, procedure-specific practice and accumulating experience are crucial for improving cardiac surgery outcomes.