Contemporary Outcomes of Acute Coronary Syndromes in Indigenous Compared with Non-Indigenous Patients: A Northern Saskatchewan Perspective

Background In patients presenting with an acute coronary syndrome (ACS), the impact of efforts leveraged at bridging historical care gaps between Indigenous and non-Indigenous patients remains limited. Methods For consecutive ACS presentations (STEMI and NSTEMI/UA, respectively) at the Royal University Hospital, Saskatoon, we compared between self-identified Indigenous and non-Indigenous patients their demographics, treatments and all-cause mortality (in-hospital and 3-years). We used propensity score-inverse probability weighting to mitigate confounding, and Cox regression models to estimate the adjusted hazard (aHR, 95% confidence intervals) for all-cause mortality. Results Of 3946 ACS patients, 37.2% (n=1468) were STEMI of whom 11.3% (n=166) were Indigenous. Of the NSTEMI/UA (n=2478), 12.6% (n=311) were Indigenous. Overall, Indigenous compared with non-Indigenous patients were likely to be younger, female, have higher risk burden, and lived more remotely; Indigenous STEMI patients triaged to primary PCI had longer first medical contact-to-device times, while Indigenous NSTEMI/UA patients more likely to present with heart failure, cardiac arrest and/or cardiogenic shock.No significant differences were noted for in-hospital mortality (STEMI 8.4% vs 5.7%, p= 0.16; NSTEMI/UA 1.9% vs 1.6%, p=0.68), however, in follow-up, Indigenous STEMI patients associated with a higher all-cause mortality risk (aHR 1.98, 95% CI 1.19, 3.31, p=0.009) with no between-group differences evident for NSTEMI/UA (aHR 1.03, 95% CI 0.63 1.69, p=0.91). Conclusions Indigenous compared with non-Indigenous patients presenting with an ACS had higher cardiovascular risk profiles, and consequently residual mortality risk. Improving primary care and intensifying secondary risk reduction, and particularly so for Indigenous patients, will substantially modify ACS outcomes in Saskatchewan.