Volume-Outcome Relationship of Resternotomy Coronary Artery Bypass Grafting

Area of Science:

• Cardiovascular Surgery
• Health Services Research
• Surgical Outcomes

Background:

• Assessing the relationship between surgical case volume and patient outcomes is crucial for quality improvement in cardiac surgery.
• Resternotomy coronary artery bypass grafting (CABG) is a complex procedure with potentially higher risks.
• Understanding factors influencing resternotomy CABG outcomes can guide surgical practice and patient selection.

Purpose of the Study:

• To evaluate the association between surgical case volume and outcomes for resternotomy coronary artery bypass grafting (CABG).
• To determine whether hospital-level or surgeon-level volume is a more significant predictor of resternotomy CABG success.
• To identify optimal case volume thresholds for improving patient safety in resternotomy CABG.

Main Methods:

• Analysis of 1,362,218 first-time CABG and 93,985 resternotomy CABG cases from The Society of Thoracic Surgeons Adult Cardiac Surgery Database (2010-2019).
• Comparison of in-hospital mortality and mortality and morbidity (M&M) rates across hospital and surgeon volume categories.
• Application of multivariable generalized linear mixed-effects models to assess volume-outcome relationships, adjusting for patient characteristics and clustering effects.

Main Results:

• Unadjusted mortality and M&M rates for resternotomy CABG declined with increasing hospital and surgeon case volume.
• Optimal outcomes were observed beyond annual volumes of 200-300 cases for hospitals and 100-150 cases for surgeons.
• Higher procedural volume was significantly associated with improved surgeon-level outcomes (mortality AOR 0.39, M&M AOR 0.37 per 100 procedures), but hospital-level associations were not significant.

Conclusions:

• Individual surgeon experience, reflected in procedural volume, is the primary determinant of improved outcomes in resternotomy CABG.
• Institutional or hospital-level volume did not show a statistically significant association with improved resternotomy CABG outcomes after adjustment.
• Focusing on surgeon-specific experience may be more impactful for enhancing the quality of care in resternotomy CABG procedures.