Outcomes following percutaneous coronary revascularization among South Asian and Chinese Canadians

Background: Previous data suggest significant ethnic differences in outcomes following percutaneous coronary revascularization (PCI), though previous studies have focused on subgroups of PCI patients or used administrative data only. We sought to compare outcomes in a population-based cohort of men and women of South Asian (SA), Chinese and "Other" ethnicity. Methods: Using a population-based registry, we identified 41,792 patients who underwent first revascularization via PCI in British Columbia, Canada, between 2001 and 2010. We defined three ethnic groups (SA, 3904 [9.3%]; Chinese, 1345 [3.2%]; and all "Others" 36,543 [87.4%]). Differences in mortality, repeat revascularization (RRV) and target vessel revascularization (TVR), at 30 days and from 31 days to 2 years were examined. Results: Adjusted mortality from 31 days to 2 years was lower in Chinese patients than in "Others" (hazard ratio [HR] 0.72; 95% confidence interval [CI] 0.53-0.97), but not different between SAs and "Others". SA patients had higher RRV at 30 days (adjusted odds ratio [OR] 1.30; 95% CI: 1.12-1.51) and from 31 days to 2 years (adjusted hazard ratio [HR] 1.17; 95% CI: 1.06-1.30) compared to "Others". In contrast, Chinese patients had a lower rate of RRV from 31 days to 2 years (adjusted HR 0.79; 95% CI: 0.64-0.96) versus "Others". SA patients also had higher rates of TVR at 30 days (adjusted OR 1.35; 95% CI: 1.10-1.66) and from 31 days to 2 years (adjusted HR 1.19; 95% CI: 1.06-1.34) compared to "Others". Chinese patients had a lower rate of TVR from 31 days to 2 years (adjusted HR 0.76; 95% CI: 0.60-0.96). Conclusions: SA had higher RRV and TVR rates while Chinese Canadians had lower rates of long-term RRV, compared to those of "Other" ethnicity. Further research to elucidate the reasons for these differences could inform targeted strategies to improve outcomes.