Intracoronary Thrombolysis in ST-Segment Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention: an Updated Meta-analysis of Randomized Controlled Trials.

backgroundPrimary percutaneous coronary intervention (PPCI) is the standard reperfusion treatment in ST-segment elevation myocardial infarction (STEMI). Intracoronary thrombolysis (ICT) may reduce thrombotic burden in the infarct-related artery, which is often responsible for microvascular obstruction and no-reflow.

methodsWe conducted, according to the PRISMA statement, the largest meta-analysis to date of ICT as adjuvant therapy to PPCI. All relevant studies were identified by searching the PubMed, Scopus, Cochrane Library, and Web of Science.

resultsThirteen randomized controlled trials (RCTs) involving a total of 1876 patients were included. Compared to the control group, STEMI ICT-treated patients had fewer major adverse cardiac events (MACE) (OR 0.65, 95% CI, 0.48-0.86, P = 0.003) and an improved 6-month left ventricular ejection fraction (MD 3.78, 95% CI, 1.53-6.02, P = 0.0010). Indices of enhanced myocardial microcirculation were better with ICT (Post-PCI corrected thrombolysis in myocardial infarction (TIMI) frame count (MD - 3.57; 95% CI, - 5.00 to - 2.14, P < 0.00001); myocardial blush grade (MBG) 2/3 (OR 1.76; 95% CI, 1.16-2.69, P = 0.008), and complete ST-segment resolution (OR 1.97; 95% CI, 1.33-2.91, P = 0.0007)). The odds for major bleeding were comparable between the 2 groups (OR 1.27; 95% CI, 0.61-2.63, P = 0.53).

conclusionsThe present meta-analysis suggests that ICT was associated with improved MACE and myocardial microcirculation in STEMI patients undergoing PPCI, without significant increase in major bleeding. However, these findings necessitate confirmation in a contemporary large RCT.