Long-term outcomes in high-risk patients with non-ST-segment elevation myocardial infarction

Abstract

Greater use of evidence-based therapies has improved outcomes for patients with acute coronary syndromes (ACS) in recent decades. Consequently, more ACS patients are surviving beyond 12 months; however, limited data exist to guide treatment in these patients. Long-term outcomes have not improved in non-ST-segment elevation myocardial infarction (NSTEMI) patients at the same rate seen in ST-segment elevation myocardial infarction patients, possibly reflecting NSTEMI patients' more complex clinical phenotype, including older age, greater burden of comorbidities and higher likelihood of a previous myocardial infarction (MI). This complexity impacts clinical decision-making, particularly in high-risk NSTEMI patients, in whom risk-benefit assessments are problematical. This review examines the need for more effective long-term management of NSTEMI patients who survive ≥12 months after MI. Ongoing risk assessment using objective measures of risk (for bleeding and ischemia) should be used in all post-MI patients. While 12 months appears to be the optimal duration of dual antiplatelet therapy for most patients, this may not be the case for high-risk patients, and more research is urgently needed in this population. A recent subgroup analysis from the DAPT study in patients with or without MI who had undergone coronary stenting (31 % presented with MI; 53 % had NSTEMI) and the prospective PEGASUS-TIMI 54 trial in patients with a prior MI and at least one other risk factor (40 % had NSTEMI) demonstrated that long-term dual antiplatelet therapy improved cardiovascular outcomes but increased bleeding. Further studies will help clarify the role of dual antiplatelet therapy in stable post-NSTEMI patients.

Keywords: Acute coronary syndromes; Dual antiplatelet therapy; Non-ST-segment elevation myocardial infarction.

Fig. 1

Kaplan–Meier curves for the primary composite end point of cardiovascular death, MI, or stroke in subgroups of patients. a Patients with prior MI in CHARISMA [13]; b Patients with prior MI in the TRA2°P-TIMI 50 trial [9]; c Patients with established coronary artery disease who had not had an MI in CHARISMA [13]. ASA aspirin, CI confidence interval, HR hazard ratio Panels a + c are reprinted from J Am Coll Cardiol 49 (19), Bhatt DL et al. ‘Patients with prior myocardial infarction, stroke, or symptomatic peripheral arterial disease in the CHARISMA trial.’ 1982–1988, copyright (2007), with permission from Elsevier. Panel b is reprinted from The Lancet 380, Scirica BM et al. ‘Vorapaxar for secondary prevention of thrombotic events for patients with previous myocardial infarction: a prespecified subgroup analysis of the TRA2°P-TIMI 50 trial.’ 1317–1324, copyright (2012) with permission from Elsevier

Fig. 2

Prasugrel use by mortality and bleeding risk in the NSTEMI population of the ACTION registry [42]. Reproduced from Sherwood MW et al. ‘Early clopidogrel versus prasugrel use among contemporary STEMI and NSTEMI patients in the US: insights from the National Cardiovascular Data Registry. J Am Heart Assoc 2014;3:e000849, with permission from Wiley. ©2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell