Coronary dominance and prognosis of patients with acute coronary syndrome

Background A number of studies have identified the number of diseased vessels to be an important determinant of survival in patients with acute coronary syndrome (ACS). It is unknown if coronary dominance has an impact on prognosis of these patients. We hypothesized that the prognosis of patients with ACS with left dominance (LD) would be worse than that of patients with right or mixed dominance. Methods The study population consisted of 27 289 patients whose primary indication for cardiac catheterization was ACS. The patients were divided into 3 groups according to coronary dominance. The mean duration of follow-up was 3.5 years (range 1-6.5 years). A Cox proportional hazards analysis was used to compare survival by dominance, adjusting for age, sex, diagnosis, comorbidities, severity of coronary disease, and ejection fraction. Results The rates and patterns of revascularization among patients with significant coronary disease were similar between the groups. At the end of follow-up, patients with LD had a significantly higher mortality (hazard ratio 1.18, 95% CI 1.05-1.34; adjusted hazard ratio 1.13, CI 1.00-1.28). The mortality of patients with mixed and right dominance was similar. Conclusion In patients with ACS, LD is a significant and independent predictor of increased long-term mortality. Further research is needed to determine mechanisms of increased mortality in patients with LD and measures that can be taken to improve the outcome of patients with left-dominant circulation.