Ultrasound enhanced prehospital thrombolysis using microbubbles infusion in patients with acute ST elevation myocardial infarction: pilot of the Sonolysis study.

In animal studies, transthoracic ultrasound and microbubbles have shown to dissolve thrombi in ST elevation myocardial infarction (STEMI). To examine this effect in patients, we have initiated the Sonolysis trial. In this pilot study of 10 patients with a first acute STEMI, we investigated the safety and feasibility of this trial. After pretreatment in the ambulance, five patients were randomized to receive microbubbles with three-dimensional (3-D) guided high mechanical index impulses (1.18) for 15 min, whereas the control group received placebo without ultrasound. Subsequently, primary percutaneous coronary intervention (PPCI) was performed, if indicated. All patients successfully underwent study treatment and PPCI. No significant difference between treatment and control group in safety (minor adverse events 2/5 vs. 2/5, p = NS) and outcome (TIMI III flow 3/5 vs. 1/5 respectively, p = 0.23) was recorded. These results demonstrate that the study protocol is feasible in the acute cardiac care setting and safe during treatment and follow-up.