Pharmaco-invasive Strategy and Dosing of Tenecteplase in STEMI Patients 60 to <75 Years: an Inter-trial Comparison of the STREAM-1 and STREAM-2 Trials

BACKGROUND:Previous studies indicate a safety risk with full-dose TNK in elderly patients. In a study of patients ≥60 years STREAM-2 (STrategic Reperfusion Early After Myocardial infarction-2), a pharmaco-invasive (PI) strategy with half-dose TNK was similar (in efficacy and safety) to primary percutaneous coronary intervention (PPCI) in ST-elevation myocardial infarction (STEMI) patients presenting <3 hours. While no treatment difference ± 75 years was observed, the role of this half-dose PI strategy in patients <75 years is unknown. In this comparison of STEAM-1 and -2, we analyzed PI strategies with full-dose (STREAM-1) versus half-dose TNK (STREAM-2) to evaluate their relative efficacy and safety in this younger STEMI cohort. METHODS:We evaluated patients 60 to <75 years from STREAM-1 and STREAM-2 receiving PI treatment versus PPCI for their resolution of ST-elevation after fibrinolysis and angiography, primary efficacy composite of 30-day all-cause death, myocardial infarction, heart failure, and shock, and safety events. RESULTS:Among 1103 patients, 327 received a full-dose PI strategy (STREAM-1), 289 a half-dose PI strategy (STREAM-2) and 487 PPCI (338 in STREAM-1; 149 in STREAM-2). Half- compared to full-dose TNK resulted in similar proportions of patients achieving ST resolution ≥50% (71.2% vs 68.7%, P = .519): their ICH risks were 2.1% vs 1.5%, P = .605 respectively). Following angiography, PI patients had nominally better ST resolution ≥50% compared to their PPCI counterpart (STREAM-1: 87.7% vs. 83.2%, P = .120; STREAM-2: 88.2% vs. 81.0%, P = .048) with similar primary composite outcome at 30 days (STREAM-1: 14.4% vs. 16.3%, 0.90 [0.62, 1.31]; STREAM-2: 9.0% vs 8.1%, 1.29 [0.64, 2.61]). Major (non-ICH) bleeding markedly declined in STREAM-2 compared to STREAM-1 in both treatment groups (STREAM-1: 7.1% vs. 6.0%; STREAM-2: 0.3% vs. 0.7%). CONCLUSIONS:In STEMI patients 60 to <75 years presenting within 3 hours of symptoms, half-dose PI treatment appears as efficacious as a full-dose PI strategy with a low systemic bleeding risk. Half-dose PI treatment deserves consideration when timely PPCI is not attainable in this important STEMI sub-group. CLINICALTRIALS: GOV REGISTRATION NUMBERS:NCT00623623, NCT02777580.