We explored for geographic variations in coronary atheroma progression rates in the United States compared to other world regions (Canada, Latin America, Western Europe, and Central-Eastern Europe) and sought to ascertain if this associated with regional differences in major adverse cardiovascular events (MACE; cardiovascular death, nonfatal myocardial infarction, coronary revascularization). Across 7 randomized trials with a global recruitment pattern, 5,451 participants with angiographic coronary disease underwent serial coronary intravascular ultrasonography during 18 or 24 months, with adjudicated MACE. Change in coronary percent atheroma volume (ΔPAV) and MACE in the United States versus other world regions were assessed. Despite similar baseline angiographic and plaque characteristics across participants and regions, following propensity-weighted and multivariate analysis, US (n = 3,706) versus non-US (n = 1,745) participants demonstrated marginal but significantly greater annualized ΔPAV (least-square means ± SE: 0.27 ± 0.14% vs 0.062 ± 0.14%, p = 0.005). However, MACE rates were disproportionately higher in US compared to non-US participants (23.5% vs 10.9%, p <0.001), driven by a doubling in crude rates of coronary revascularization procedures (16.1% vs 7.8%, p <0.001). The US participants hospitalized with unstable angina demonstrated more significant disease progression than their non-US counterparts (ΔPAV: 0.57 ± 0.19% vs -0.30 ± 0.36%, p = 0.033) and greater MACE (9.1% vs 4.8%, p <0.001). A US geographic disposition independently associated with MACE (hazard ratio 1.53, 95% confidence interval 1.22 to 1.92, p <0.001). In conclusion, in participants with stable coronary disease, coronary atheroma progression rates are modestly higher in US-based compared to non-US-based participants. Elective coronary revascularization rates however are disproportionately greater in US-based participants.
Copyright © 2016 Elsevier Inc. All rights reserved.