ABSTRACT
Objective To analyze the incidence,risk factors,and impact of intraoperative conversion on the mortality in patients undergoing off-pump coronary artery bypass grafting.Methods This retrospective observational study included 207 patients undergoing off-pump coronary artery bypass grafting.According to whether intraoperative conversion,207 patients were randomly divided into intraoperative unchanged group(191 cases)and intraoperative changed group(16 cases).The incidence,patient characteristics,cause of intraoperative conversion,and its impact on outcome were studied.Results Intraoperative conversion increases odds for mortality to 25.0%,while the other group was 1.0%.The most common cause for intraoperative conversion was hemodynamic disturbances during grafting to the obtuse marginal artery.On multivariate logistic regression analysis,left main disease,mitral regurgitation and higher EuroSCORE II independently predicted intraoperative conversion.Conclusion Intraoperative conversion to on-pump coronary artery bypass grafting is independently associated with higher mortality in patients undergoing off-pump coronary artery bypass grafting.Identification of high risk group of intraoperative conversion may improve the outcome.
ABSTRACT
Context: One of the main limitations of off‑pump coronary artery bypass grafting (OPCAB) is the occasional need for intraoperative conversion (IOC) to on‑pump coronary artery bypass grafting. IOC is associated with a significantly increased risk of mortality and postoperative morbidity. The impact of IOC on outcome cannot be assessed by a randomized control design. Aims: The objective of this study was to analyze the incidence, risk factors, and impact of IOC on the outcome in patients undergoing OPCAB. Settings and Design: Three tertiary care level hospitals; retrospective observational study. Subjects and Methods: This retrospective observational study included 1971 consecutive patients undergoing OPCAB from January 2012 to October 2015 at three tertiary care level hospitals by four surgeons. The incidence, patient characteristics, cause of IOC, and its impact on outcome were studied. Statistical Analysis Used: The cohort was divided into two groups according to IOC. Univariate logistic regression was performed to describe the predictors of IOC. Variables that were found to be significant in univariate analysis were introduced into multivariate model, and adjusted odds ratio (OR) was calculated. To further assess the independent effect of IOC on mortality, propensity score matching with a 5:1 ratio of non‑IOC to IOC was performed. Results: The overall all‑cause in‑hospital mortality was 2.6%. IOC was needed in 128 (6.49%) patients. The mortality in the IOC group was significantly higher than non‑IOC group (21 of 128 [16.4%] vs. 31 of 1843 [1.7%], P = 0.0001). The most common cause for IOC was hemodynamic disturbances during grafting to the obtuse marginal artery (51/128; 40%). On multivariate logistic regression analysis, left main disease, pulmonary hypertension, and mitral regurgitation independently predicted IOC. We obtained a propensity‑matched sample of 692 patients (No IOC 570; IOC 122), and IOC had OR of 16.26 (confidence interval 6.3–41; P < 0.0001) for mortality in matched population. Conclusions: Emergency IOC increases odds for mortality by 16‑fold. Hence, identification of patients at higher risk of IOC may improve the outcome.