Therapeutic use of ultrasound in an acute and chronic coronary artery disease

Abstract

In acute coronary artery disease, pre-clinical studies have indicated that, during a continuous infusion of intravenous perfluorocarbon containing micro bubbles, the ultrasonic power delivered from a diagnostic ultrasound transducer is capable of restoring microcirculatory flow and improving epicardial recanalization rates obtained by conventional therapy, a process known by Sonothrombolysis. Since both diagnostic ultrasound and intravenous infusions of micro bubbles are a Class I indication to assess regional and global left ventricular function and risk area in patients with ST segment elevation myocardial infarction, we propose to examine whether diagnostic assessments of left ventricular function and risk area size impacts epicardial recanalization rates and infarct size in ST segment elevation myocardial infarction. In the spectrum of chronic coronary artery disease, a new Shockwave Therapy (SWT) was developed recently which couples the ability of low intensity shock waves to induce angiogenesis to the therapy of angina and is becoming a new alternative in the treatment of these patients. Reversible ischemic regions, no longer approachable or treatable by exiting invasive methods are being targeted and treated with SWT. Short and long term results have shown the ability of this new therapy to increase local perfusion, reduce symptoms and improve overall quality of life of patients. High intensity extracorporeal shock waves are used for renal and cholelithotripsy. Studies have shown that low-intensity SWT increases capillary density and regional myocardial blood flow in animal and human experiments a process known as Sonoangiogenesis. Shock waves are waves of frequencies within the range of ultrasound (100 KHz to 1 MHz), which have some peculiarities in relation to the latter. Among them, there is high energy (100 MPa), in opposition to the ultrasound used for medical diagnosis which uses low energy (>0.5 MPa). However, unlike the treatment of acute coronary syndromes, it is unknown whether the combination this therapy can be improved with SWT association with micro bubbles injected intravenously. We hypothesized that SWT might be beneficial in patients suffering from severe chronic angina pectoris (CCS class III or IV) refractory to individually optimized medical treatment not suitable for percutaneous or surgical revascularization. Since coronary artery disease accounts for nearly 20% of deaths worldwide and increasingly consumes nearly 20% of the resources of the National Health System in Brazil. This innovative therapy has the potential to improve treatment outcomes for the various existing coronary syndromes and reduce the number of hospitalizations and myocardial revascularization in this population of Brazilians. (AU)