Postrevascularization Survival among South Asians Admitted with an Acute Coronary Syndrome

Summary

Canadians of South Asian ancestry treated with coronary artery bypass graft (CABG) or percutaneous coronary intervention (PCI) have improved long-term survival but higher rates of repeat revascularization with PCI compared with Canadians of European descent. This article presents data from a study comparing short- and long-term clinical outcomes among Canadians of South Asian and European descent admitted to the hospital with acute coronary syndrome.

  • Interventional Techniques & Devices Clinical Trials
  • Coronary Artery Disease
  • Interventional Techniques & Devices
  • Cardiology Clinical Trials
  • Coronary Artery Disease
  • Cardiology

Canadians of South Asian ancestry treated with coronary artery bypass graft (CABG) or percutaneous coronary intervention (PCI) have improved long-term survival but higher rates of repeat revascularization with PCI compared with Canadians of European descent. Kevin R. Bainey, MD, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada, presented data from a study comparing short- and long-term clinical outcomes among Canadians of South Asian and European descent admitted to the hospital with acute coronary syndrome (ACS).

With the growing migration of South Asians to North America, there is an increased need for physicians to be aware of ethnic differences associated with coronary artery disease (CAD) [Bainey KR and Jugdutt BL. Atherosclerosis 2009]. South Asians living in Canada have a greater prevalence of atherosclerosis [Anand SS et al. Lancet 2000] and high rates of CAD mortality [Sheth T et al. CMAJ 1999] that occurs at a younger age [Yusuf S et al. Lancet 2004]. Canadians of South Asian descent with CAD also have significantly worse health outcomes 1 year after angiography compared with Canadians of European ancestry. One-year adjusted mean (SD) scores were significantly lower in South Asian angina frequency (86 [23] vs 88 [20]), treatment satisfaction (86 [19] vs 89 [16]), and quality of life (71 [24] vs 76 [21]; p<0.001 for all) [Bainey KR et al. Am Heart J 2011].

The objective of this large, prospective, comprehensive clinical registry study was to compare short- and long-term clinical outcomes of South Asian and European Canadian patients admitted with ACS. A validated names analysis program was used to identify South Asian surnames for patients listed in the Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease database, an ongoing prospective data collection initiative that tracks patients having balloon angioplasty, the type and location of coronary artery stents, as well as previous or subsequent revascularization by CABG or PCI. A 3:1 propensity-matched technique was used to reduce variability and improve biased reduction.

Of the 68,108 patients with ACS undergoing coronary angiography between 1999 and 2012, 1823 were South Asian and 61,260 were of European descent. There were no significant differences in 30-day and 1-year mortality rates, or 1-year repeat angiogram rates between the two groups. Propensity-matched, adjusted, 1-year repeat revascularization rates with PCI were significantly higher for South Asian compared with European patients (6.0% vs 3.6%; p<0.01). There was no difference in 1-year repeat revascularization among patients receiving CABG (4.8% vs 5.6%; p=0.75). Long-term survival for propensity-matched, adjusted ACS patients was significantly higher (p<0.01) for South Asian Canadians (Figure 1) particularly with revascularization.

It should be noted that the use of name recognition software, versus self-identification, may have resulted in the incorrect assignment of some subjects because of interracial marriage or religious conversion/name change. In addition, the use of propensity-matched analysis may not control for unmeasured confounders between South Asian and European Canadian patients.

These data indicate the need for clinicians to be more sensitive to ethnic-based outcomes and therapeutic strategies in the treatment of ACS.

Figure 1.

Comparison of Long-Term Mortality in South Asian and European ACS Patients

Reproduced with permission from KR Bainey, MD.
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