Eighteen-year trends in cardiovascular risk and mortality in patients with acute coronary syndrome without ST-segment elevation

Abstract Background The management of patients with non-ST-segment elevation myocardial infarction (NSTEMI) and unstable angina pectoris (UAP) has changed substantially within the past decades. We examined temporal trends in the management and two-year clinical outcomes following a first-time NSTEMI/UAP event between 2004 and 2021 in Western Denmark. Methods We included patients without previous history of ischemic heart disease referred to coronary angiography due to NSTEMI/UAP and excluded patients without angiographic evidence of coronary artery disease (CAD). Patients were stratified by examination year (2004-2006, 2007-2009, 2010-2012, 2013-2015, 2016-2018, and 2019-2021). We examined trends in diagnostic patterns of CAD extent and post-procedural anti-thrombotic and lipid-lowering treatment. Clinical outcomes were 2-year risk of myocardial infarction, cardiovascular death, and all-cause death, as well as 90-day coronary revascularization rates. We estimated cumulative incidence proportions and adjusted incidence rate ratios (aIRR) using patients examined in 2004-2006 as the reference. Results A total of 25,959 patients were included, with a median age of 67 years (Q1-Q3 58-76) and 68.1% were males. Fewer patients were diagnosed with obstructive CAD (96% in 2004-2006 versus 79% in 2019-2021); a trend which coincided with a gradual increase in the use of pressure wires (from 0.6% to 10.2%) and intracoronary imaging (from 2.8% to 9.2%). The 90-day rate of percutaneous coronary intervention decreased from 71% to 61% (aIRR 0.71, 95% CI 0.65-0.78) and coronary artery bypass grafting from 18% to 10% (aIRR 0.50, 95% CI 0.44-0.57) from 2004-2006 to 2019-2021 (Figure 1). We observed a transition to more potent anti-thrombotic agents (from clopidogrel to ticagrelor and prasugrel) and high-intensity statins (from simvastatin to atorvastatin and rosuvastatin). The 2-year risk of recurrent myocardial infarction decreased from 5.4% to 3.1% (aIRR 0.54, 95% CI 0.43-0.68) and cardiovascular death was reduced from 5.3% to 3.9% (aIRR 0.64, 95% CI 0.45-0.79) (Figure 2). However, all-cause death was stable throughout the study period (9.1% in 2004-2006; 9.8% in 2019-2021; aIRR 0.95, 95% CI 0.81-1.11). Conclusions These real-world data demonstrate a substantial decline in the 2-year risk of recurrent myocardial infarction and cardiovascular death following a first-time NSTEMI/UAP event between 2004 and 2021. The improvements in cardiovascular risk coincided with 1) changes in the diagnostic evaluation of obstructive CAD, 2) a reduction in coronary revascularization – in particular a 50% decline in coronary bypass surgery, and 3) optimized medical therapy.Figure 1 Figure 2