Elucidation of the novel role of ethnicity and diabetes in poorer outcomes after cardiac surgery in a multiethnic Southeast Asian cohort

BACKGROUND: Although diabetes is associated with ethnicity and worse cardiac surgery outcomes, no research has been done to study the effect of both diabetes and ethnicity on cardiac surgery outcomes in a multiethnic Southeast Asian cohort. Hence, this study aimed to delineate the association of ethnicity on outcomes after cardiac surgery among diabetics in a multiethnic Southeast Asian population.

METHODS: Perioperative data from 3008 adult patients undergoing elective cardiac surgery from 2008 to 2011 at the two main heart centers in Singapore was analyzed prospectively, and confirmatory analysis was conducted with the generalized structural equation model.

RESULTS: Diabetes was significantly associated with postoperative acute kidney injury (AKI) and postoperative hyperglycemia. Postoperative AKI, Malay ethnicity, and blood transfusion were associated with postoperative dialysis. Postoperative AKI and blood transfusion were also associated with postoperative arrhythmias. In turn, postoperative dialysis and arrhythmias increased the odds of 30-day mortality by 7.7- and 18-fold, respectively.

CONCLUSIONS: This study identified that diabetes is directly associated with postoperative hyperglycemia and AKI, and indirectly associated with arrhythmias and 30-day mortality. Further, we showed that ethnicity not only affects the prevalence of diabetes, but also postoperative diabetes-related outcomes.