Feasibility of sonothrombolysis in the ambulance for ST-elevation myocardial infarction

Abstract

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Lantheus Medical Imaging, Inc., North Billerica, MA Background Patients with ST-elevation myocardial infarction (STEMI) due to coronary occlusion require immediate restoration of epicardial and microvascular blood flow. A potentially new reperfusion method is the use of ultrasound and microbubbles, also called sonothrombolysis. The oscillation and collapse of intravenously administered microbubbles upon exposure to high mechanical index (MI) ultrasound pulses results in thrombus dissolution and stimulates nitric oxide-mediated increases in tissue perfusion. The aim of this study was to assess feasibility of sonothrombolysis in the ambulance for STEMI patients. Methods Patients presenting with chest pain and ST-elevations on initial electrocardiogram were included. Sonothrombolysis was applied in the ambulance during patient transfer to the percutaneous coronary intervention (PCI) center. Feasibility was assessed based on duration of sonothrombolysis treatment and number of high MI pulses applied. Vital parameters, ST-resolution, pre- and post-PCI coronary flow and cardiovascular magnetic resonance images were analyzed. Follow up was performed at six months after STEMI. Results Twelve patients were screened, of which three patients were included in the study. Sonothrombolysis duration and number of high MI pulses ranged between 12-17 minutes and 32-60 flashes respectively. No changes in vital parameters were observed during and directly after sonothrombolysis. In one case, sonothrombolysis on top of regular pre-hospital care resulted in reperfusion, in another case the effect was inconclusive, and in the last case no effect was seen on reperfusion or definite infarct size. Conclusion Sonothrombolysis in the ambulance for STEMI patients is feasible. Larger clinical trials on efficacy and safety of pre-hospital sonothrombolysis are needed. Abstract Figure. Sonothrombolysis set-up in the ambulance Abstract Figure. Sonothrombolysis case with reperfusion