Abstract 5615: A Comparison of Early Invasive Versus Conservative Therapy for Non-ST Elevation Myocardial Infarction Patients Excluded from Clinical Trials
Background: Randomized clinical trials (RCT) have tested the efficacy of early invasive (EI) versus conservative (CON) strategies for managing non-ST-elevation myocardial infarction (NSTEMI). However, RCT’s often have restricted entry criteria that limit external validity and exclude high risk patients. This leaves clinicians with little evidence to guide the appropriate management of NSTEMI patients that would have been ineligible for traditional RCT’s.
Methods: We sought to understand the outcomes of EI versus CON strategies in managing NSTEMI in a prospective cohort of patients that would have been ineligible for entry into the TACTICS TIMI 18 trial. The data source for this study is PREMIER. PREMIER is a multi-center observational registry of 1,409 NSTEMI patients. The definitions for EI and CON strategies were the same as in TACTICS TIMI 18. Propensity score matching was used to adjust for biases in treatment selection, baseline characteristics and site between the EI and CON groups. Stratified proportional hazards regression was used to compare 1-and 3-year survival and 1-year rehospitalization between groups.
Results: Of the 1,409 NSTEMI patients enrolled in PREMIER, 686 patients (49%) would have been excluded from TACTICS TIMI 18. Of these, 227 (33%) received an EI approach and 459 (67%) received a CON approach to managing their NSTEMI. With propensity score matching 174 pairs were identified for comparison. After matching, there were no significant differences in baseline characteristics between the EI and CON groups. While there was no difference in 1-year rehospitalization between CON vs. EI patients (HR 1.18, 95% CI 0.79 –1.77), the CON group had a significantly higher 1-year (HR 2.27, 95% CI 1.24 – 4.16) and 3-year mortality (HR 1.67, 95% CI 1.06 –2.62).
Conclusion: Nearly half of all NSTEMI patients enrolled in PREMIER would have been ineligible for enrollment into TACTICS TIMI 18, and two thirds of these ineligible patients received a CON approach. Compared with CON management among propensity-matched ineligible patients, the EI approach was associated with significantly lower 1 and 3-year mortality. These results suggest that NSTEMI patients ineligible for TACTICS TIMI 18 still benefit from management by an EI approach.