Outcomes after cardiac surgery: are women of South Asian origin at increased risk?

Abstract

Objectives The population served by our centre has a relatively high proportion of people originating from the Indian subcontinent (“South Asians”) compared to the national average (14.3% vs 4.6%). We observed that the mortality rate in South Asian women undergoing cardiac surgery in our unit appeared to be relatively high. We investigated this observation further to determine whether ethnic origin was an independent risk factor for postoperative death in females. Methods Data for all patients undergoing cardiac surgery were collected prospectively in a registry. Retrospective analysis was carried using SPSS on data for 4901 patients operated on in the 6- year period April 2004 to March 2010. Categorical data associated with mortality were analysed using c2 tests. Risk factors for inhospital mortality were subjected to univariate analysis, and those found to be significant were tested for independence using multivariate logistic regression. Results During the study period, 1160 female patients underwent surgery with a mortality rate of 4.7%. Mortality in 113 South Asians was 8.9% vs 4.3% in non-Asians (p¼0.03). Of 20 risk factors tested with univariate analysis, 16 were significantly associated with mortality. Logistic regression showed the following to be independent predictors of postoperative mortality: urgency of operation (OR 32.0; p<0.001), older age (OR 24.2; p<0.001), preoperative renal dysfunction (OR 15.8; p<0.001), diabetes (OR 7.8; p¼0.005), South Asian ethnicity (OR 7.3; p¼0.007), extra-cardiac arteriopathy (OR 4.8; p¼0.028), and an operation other than isolated CABG (OR 5.8; p¼0.016). Conclusions In our population, South Asian ethnicity appears to be an independent risk factor for mortality in females undergoing cardiac surgery. Studies in larger populations are warranted.