Should Non-ST-Elevation Myocardial Infarction be Treated like ST-Elevation Myocardial Infarction With Shorter Door-to-Balloon Time?

It is estimated that each year in the United States >780,000 persons will experience an acute coronary syndrome. Approximately 70% of these will have non-ST-elevation myocardial infarction (NSTEMI). Optimal timing of angiography in NSTEMI is a matter of debate. The aim of this retrospective analysis was to evaluate whether and how the timing of percutaneous coronary intervention (PCI) affects the 1-year rate of major adverse cardiac events (MACE) in patients presenting with NSTEMI. Within our PCI database, we identified 1550 patients who underwent PCI for NSTEMI. We then divided the population into 3 groups based on door-to-balloon time (D2BT) (group 1 = D2BT <90 minutes; group 2 = D2BT >90 minutes <24 hours; group 3 = D2BT >24 hours). Primary outcome was MACE, a composite of MI, death and target vessel revascularization (TVR), or TVR at 1 year. Baseline characteristics were heterogeneous among the 3 groups, with patients who underwent angiograms >24 hours from presentation being older with more cardiovascular co-morbidities. Patients with D2BT <90 minutes were more likely to present with cardiogenic shock and had higher troponin levels. In-hospital mortality was similar among the 3 groups, but 1-year MACE/TVR was significantly higher in groups 1 and 3, driven by worse mortality. In this large cohort of patients presenting with NSTEMI, patients who underwent PCI between 90 minutes to 24 hours from presentation had better 1-year outcomes but also had fewer co-morbidities and with significantly lower prevalence of cardiogenic shock and high troponin on presentation. Therefore, treatment selection bias makes causal inference concerning rapid revascularization and outcome unreliable. Randomized clinical trials are warranted to assess outcome of rapid revascularization in patients presenting with NSTEMI.