Adjunctive Transcutaneous Ultrasound With Thrombolysis : Results of the PLUS (Perfusion by ThromboLytic and UltraSound) Trial

ObjectivesWe investigated whether transcutaneous ultrasound (TUS) augments coronary thrombolysis and achieves higher rates of Thrombolysis In Myocardial Infarction (TIMI) flow grade 3 and ST-segment resolution in patients with ST-segment elevation myocardial infarction (STEMI).BackgroundIn animal coronary and peripheral artery thrombosis models, low-frequency TUS enhances and accelerates thrombolysis.MethodsIn a double-blind, randomized, controlled international clinical trial, 396 patients with STEMI ≤6 h were randomized to thrombolysis alone or thrombolysis plus TUS. The 60 minute TIMI flow grade, ST-segment resolution (primary end points) and other angiographic, electrocardiographic, and clinical outcomes were compared between treatment groups.ResultsThe trial was halted after Safety and Efficacy Monitoring Committee interim analysis that demonstrated lack of treatment efficacy. In total, 360 patients were evaluable for angiographic, electrocardiographic, or clinical end points. Sixty minutes after thrombolytic administration, the proportion of patients achieving TIMI flow grade 3 did not differ between TUS and control groups (40.7% vs. 48.5%, respectively; p = 0.10). Achievement of >50% ST-segment resolution at 60 min did not differ between TUS and control groups (53.2% vs. 50.0%; p = 0.93). Thirty-day mortality and composite clinical events—death, reinfarction, recurrent ischemia, stroke, major bleed, left ventricular rupture (9.7 % vs. 10.2%; p = 0.88)—did not differ between TUS and control patients.ConclusionsThrombolysis plus TUS failed to improve 60-min TIMI flow grade or ST-segment resolution versus thrombolysis alone.