Outcomes of cardiac surgery in Indigenous Australians

To describe baseline characteristics, operative events and late mortality among Indigenous Australians undergoing cardiac surgery.

Prospective study of consecutive patients undergoing cardiac surgery at Flinders Medical Centre in Adelaide between January 2000 and December 2005.

Operative (30-day) mortality and late mortality after cardiac surgery.

Of 2635 patients undergoing cardiac surgery, 283 (10.7%) were Indigenous. Indigenous patients were substantially younger than non-Indigenous patients (mean, 47 [SD, 14] years v 65 [SD, 12] years; P = 0.001) and were more likely to have diabetes (39.6% v 27.3%; P = 0.001), renal dysfunction (3.2% v 1.2%; P = 0.009), and valvular surgery (53.0% v 23.1%; P < 0.001). There was a non-significant trend toward excess operative mortality in Indigenous patients (Indigenous 2.5% v non-Indigenous 1.3%; hazard ratio [HR], 1.67 [95% CI, 0.74-3.75]). But in the under-55-years age cohort, the difference between the two groups was highly significant (Indigenous 3.3% v non-Indigenous 0.4%; HR, 7.99 [95% CI, 1.66-38.50]), even after adjustment for euroSCORE (the European System for Cardiac Operative Risk Evaluation). Survival at 1 and 5 years was 94.0% and 80.6%, respectively, for Indigenous patients compared with 96.7% and 87.7%, respectively, for non-Indigenous patients. There was an excess in euroSCORE-adjusted mortality in the Indigenous cohort overall (HR, 1.46 [95% CI, 1.03-2.07]) that strengthened when restricted to the under-55-years cohort (HR, 6.9 [95% CI, 1.42-33.5]).

Indigenous Australians present for cardiac surgery nearly 20 years earlier than non-Indigenous Australians and experience excess age-stratified operative and late mortality.