OBJECTIVES

: Early results from the ISCHEMIA trial have not shown improved outcomes among patients with ischemic heart disease treated with routine invasive therapy (INV) and optimal medical therapy (OMT) in comparison with OMT on its own. This study aims to replicate the parameters of this trial using real world evidence and to characterize outcomes of INV for patients experiencing certain ischemic events.

METHODS

: Data from an EMR research network representing over 58M patient-lives was used to examine outcomes after treatment for two initial ischemic indications, angina pectoris and non-ST elevation myocardial infarction (NSTEMI), newly incident in the past five years. INV was defined as cardiac catheterization, coronary artery bypass grafting, or percutaneous coronary intervention, and OMT constituted several cardiovascular medications. INV+OMT cohorts were treated with at least one INV and one OMT within the month after the incident ischemic event. OMT cohorts were treated with OMT alone in the first month. We matched on demographic factors, comorbid ischemic events, and other risk factors, and we compared outcomes (cardiac arrest, all-cause mortality, STMEI, NSTEMI, unstable angina, heart failure, and all-cause hospitalization) between cohorts using risk ratios and 95% confidence intervals.

RESULTS

: The risk for most outcomes were significantly greater among patients treated with INV+OMT, such as STEMI [RR=2.8(CI=2.4-3.3)] and heart failure [RR=1.2(CI=1.1-1.3)] among initial angina pectoris patients, and unstable angina [RR=2.7(CI=2.3-3.1)] and secondary NSTEMI [RR=1.8(CI=1.7-1.8)] among initial NSTEMI patients. There was no difference in risk of cardiac arrest between treatments for NSTEMI. INV+OMT appeared to be protective against all-cause mortality after an NSTEMI event [RR=0.4(CI=0.4-0.5)], but there was no difference in all-cause mortality by treatment after an angina pectoris event.

CONCLUSIONS

: Routine INV may be beneficial in reducing all-cause mortality among patients with an NSTEMI event. Otherwise, this study suggests INV+OMT treatment has the same or greater risk for other relevant outcomes than OMT alone.