ABSTRACT
Background Sonothrombolysis using diagnostic ultrasound and microbubbles has been proposed as a potential adjunctive treatment that could reduce microvascular obstruction (MVO) in patients with ST-elevation myocardial infarction (STEMI). In this preliminary analysis of an ongoing randomized controlled trial on the efficacy of sonothrombolysis after percutaneous coronary intervention (PCI) in STEMI patients with MVO, we sought to assess whether a difference could be observed between the treatment and control group with respect to the occurrence of early and late serious adverse events (SAE). Methods Patients with STEMI and persistent ST-elevation on the electrocardiogram (ECG) after PCI were randomized to sonothrombolysis (> 60 high mechanical index pulses in the apical 4-, 2- and 3-chamber view during an infusion of commercially available microbubbles) or sham (low mechanical index imaging with < 6 HMI pulses for perfusion imaging). All SAEs, defined according to the International guidelines for Good Clinical Practice (ICH-GCP), were recorded and divided in early (<1 month) and late (<6 months) SAEs. Results Forty-five patients were included in the trial. In total, 12 SAEs occurred: 4 in the sonothrombolysis group (2 early, 2 late), 8 in the control group (6 early, 2 late). In the sonothrombolysis group, the SAEs consisted of out-of-hospital cardiac arrest, gastrointestinal bleeding, collapse with subdural hematoma and endocarditis. In the control group, the listed SAEs were all-cause death (2x), hospitalization for heart failure, pneumonia, COVID-infection, diabetes mellitus, non ST-elevation myocardial infarction and aspecific chest paint. Conclusion Sonothrombolysis after PCI in patients with high-risk STEMI and MVO is not associated with an increased occurrence of early or late SAEs. Further clinical trials are needed to comment on the efficacy of sonothrombolysis in this patient population.