Routine invasive strategy is of most benefit in trials that did not specify positive cardiac biomarker status as an inclusion criterion: a meta-analysis

Purpose: We further explored the hypothesis of fewer cardiac deaths among Unstable Angina and Non-ST-Elevation Myocardial Infarction (UA/NSTEMI) patients undergoing early angiography, attempting to address previous concerns on baseline risk of patients as assessed by troponin status. Methods: Only randomized controlled clinical trials reporting data on cardiac biomarkers were considered for inclusion in this meta-analysis. Routine invasive and selective invasive strategies were compared as follows: analysis 1: trials only recruiting participants with positive cardiac biomarkers (NSTEMI) versus those that recruited participants with positive and negative cardiac biomarkers as an inclusion criterion (UA/NSTEMI), regardless of stents use; analysis 2: trials selected as above, with stents deployed during procedures. The primary end-points were mortality, recurrent non fatal MI and their combination. Results: For analysis 1, a total of 8 trials (10,411 patients) were eligible for our study: 3 with NSTEMI (VINO, VANQWISH and ICTUS) and 5 with UA/NSTEMI (TIMI IIIB, MATE, FRISC II, TACTIS-TIMI 18 and RITA 3). For analysis 2, three of the eight selected trials (MATE; TIMI-3B and VANQWISH) were excluded because they were undertaken in the pre-stent era. Duration of the follow-up periods ranged from 6 to 24 months. In the period of time from randomization to the end of follow-up, the use of routine invasive strategy was associated with a significant reduction for the composite ischemic events with 21% lower odds (RR 0.79; CI, 0.70-0.90) in UA/NSTEMI. In contrast, there was no benefit of the use of such strategy (RR 1.19; CI, 1.03-1.38) in NSTEMI. The observed effects were consistent among most evaluated trials except for the case of MATE in UA/NSTEMI and VINO in NSTEMI. Regarding the period of time from randomization to discharge, a routine invasive strategy was associated with significantly higher odds of the endpoint in both UA/NSTEMI (RR 1.28; CI, 1.11-1.46) and NSTEMI (RR 1.85; CI, 1.49-2.29). Changing the methods for analysis from all randomized studies to studies that were undertaken in the post-stent era (analysis 2) did not alter the interpretation of the data. Conclusions: Contrary to expectations, a routine invasive strategy is of most benefit in trials recruiting a large number of UA patients, whereas it cannot be proven to reduce deaths or nonfatal myocardial infarction in NSTEMI patients. Potential clinical benefits from PCI do not seem to favorably affect the overall prognosis of the index myocardial infarction.