High medium-term incidence of major cardiovascular events in discharged patients with unstable angina

The introduction of high-sensitivity troponin (hsTn) assays has reduced the diagnosis of unstable angina (UA) in favor of non-ST elevation myocardial infarction (NSTEMI) in the context of non-ST elevation acute coronary syndrome (NSTEACS). It is unclear whether the detection of these hsTn levels affects the prognosis and therefore whether a different therapeutic approach is warranted. This study aims to determine whether using hsTn results in medium-term prognostic differences in patients with UA and NSTEMI. Methods: This multicenter, prospective registry study included consecutive patients who underwent hsTn assays and were discharged with a diagnosis of NSTEACS. Patients were followed for two years. Outcomes were the occurrence of major adverse cardiovascular events (MACE: cardiovascular death, non-fatal myocardial infarction, and non-fatal ischemic stroke), major bleeding, and all-cause mortality. Results: Patients with UA and NSTEMI did not show differences in terms of the invasive interventions received, the coronary artery disease diagnosed, the type of revascularization performed, or the proportion presenting MACE (UA 18.1% vs. NSTEMI 18.9%; p = 0.79). However, patients with NSTEMI had higher cardiovascular mortality at two years (UA 4% vs. NSTEMI 9.2%; p = 0.012), as well as, all-cause mortality (UA vs. 7.9% vs. NSTEMI 16.4%; p = 0.002). Conclusions: Medium-term incidence of MACE was similar in patients with UA and NSTEMI, but cardiovascular and all-cause mortality in NSTEMI patients was over twice that of patients with UA.