Influence of Cardiopulmonary Bypass Time and Aortic Cross-Clamp Time on 30-day Mortality in Low- and High-Risk Elective Patients

Background: Cardiopulmonary bypass (CPB) time and aortic cross-clamp time are critical intraoperative factors influencing mortality in cardiac surgery. However, their relative importance may differ across patient risk categories. This study compares the predictive value of CPB time and cross-clamp time in low-risk (EuroSCORE II < 8) and high-risk (EuroSCORE II ≥ 8) patient groups undergoing elective cardiac surgery.

Methods: We analyzed data of 12,395 patients, who underwent elective cardiac surgery in our clinic from 2004 to 2024. We performed univariate logistic regression analyses to assess the impact of CPB time and cross-clamp time on 30-day mortality in both low-risk and high-risk patients. Separate models were constructed for each variable, with mortality as the dependent outcome. Predictive strength was evaluated using pseudo R-squared values and regression coefficients.

Results: For low-risk patients, the odds of mortality increased by 1.48% per minute of CPB time (OR = 1.0148, p < 0.001), while cross-clamp time increased mortality odds similarly by 1.48% per minute (OR = 1.0148, p < 0.001). The pseudo R-squared values were higher for CPB time (0.0875) compared with cross-clamp time (0.051), indicating that CPB time had a stronger impact. In high-risk patients, the odds of mortality rose by 1.02% per minute of CPB time (OR = 1.0122, p < 0.001), compared with 1.10% for cross-clamp time (OR = 1.0110, p < 0.001). CPB time also had a higher predictive value (pseudo R-squared = 0.077) than cross-clamp time (pseudo R-squared = 0.053) in this group.

Conclusion: CPB time is a stronger predictor of mortality than aortic cross-clamp time in both low- and high-risk patients. However, the impact of both factors on mortality is reduced in high-risk patients, suggesting that other factors, likely related to preoperative condition and comorbidities, contribute more significantly to mortality in this group. These findings highlight the complexity of predicting outcomes in high-risk patients and suggest a need for further investigation into additional risk factors.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
11 February 2025