Safety and Efficacy of Intracoronary Thrombolysis as Adjunctive Therapy to Primary PCI in STEMI: A Systematic Review and Meta-analysis

Background Primary percutaneous coronary intervention (PPCI) is the preferred method of reperfusion in ST-elevation myocardial infarction. However, microvascular perfusion is often impaired due to distal embolization of thrombus. Intracoronary (IC) thrombolysis may attenuate thrombotic burden. We conducted a meta-analysis comparing the benefits and risks of IC thrombolytic therapy as an adjunct to PPCI. Methods Randomized controlled trials (RCTs) were identified through search of Medline, EMBASE, Scopus, Web of Science, Cochrane Library (Cochrane Reviews and Cochrane Protocols), PROSPERO, and clinicaltrials.gov from 1946 to January 2019. Studies included patients with ST-elevation myocardial infarction undergoing primary PCI receiving IC thrombolytic agents. Both safety and efficacy outcomes were explored. Data were combined using a fixed-effects model. Results Of 1278 citations identified, 6 RCTs (890 patients; 519 IC thrombolytic and 371 IC placebo) were included. Post-PCI thrombolysis in myocardial infarction (TIMI) flow grade 2/3 occurred in 97.1% of the IC thrombolytic group vs 95.1% of the IC placebo group (odds ratio [OR], 0.57; 95% confidence interval [CI], 0.28-1.17; P = 0.13). Complete ST-segment resolution was more common with IC thrombolysis (OR, 0.29; 95% CI, 0.15-0.57; P = 0.0003). There was a strong trend favouring fewer in-hospital major adverse cardiac events with IC thrombolysis when compared with IC placebo (OR, 0.64; 95% CI, 0.41-1.01; P = 0.05). There was no difference in bleeding (TIMI major, TIMI minor, and Bleeding Academic Research Consortium [BARC] 3-5 bleeds) between the 2 groups (OR, 1.36; 95% CI, 0.38-3.54; P = 4.84). Conclusions Given the limited studies to date, our meta-analysis suggests that a targeted IC thrombolytic approach is safe and potentially effective to augment PPCI. However, these findings deserve confirmation in a larger RCT.