Preliminary clinical results with intracoronary ultrasound angioplasty

Abstract

BASIS AND AIM OF STUDY: Low-frequency, high-intensity ultrasound has been shown, both in vivo and in vitro, selectively to remove arteriosclerotic plaques and thrombi. This study was undertaken to investigate the safety and effectiveness of intracoronary ultrasound angioplasty. Ultrasound coronary angioplasty (UCA) with highly flexible ultrasound catheters (1.2 mm or 1.7 mm probe tip) was performed in 50 patients (36 men, 14 women; mean age 64.7 [33-79] years) with coronary heart disease involving one (n = 26 or several (n = 24) vessels. Indications for treatment were exercise-induced (n = 35) or unstable (n = 14) angina or acute myocardial infarction (n = 11). Treated lesions were in the anterior interventricular branch (n = 25), circumflex branch of the left coronary artery (n = 3) and right coronary artery (n = 22). 19 vessels were occluded, 24 lesions were partially thrombosed, 19 were calcified. 22 stenoses were longer than 20 mm. According to AHA/ACC criteria, 10 type A, 17 type B1, 6 type B2 and 17 type C lesions were treated. Total ultrasound time was 336 +/- 308 s; mean passing time through the stenosis was 233 +/- 289 (10-556) s. 17 of 19 occlusions were recanalised after 285 +/- 224 s. Percutaneous transluminal angioplasty (PTCA) was subsequently performed in 49 patients. The mean stenosis grade was reduced by UCA from initially 82 +/- 3 to 64 +/- 2% and by subsequent PTCA to 38 +/- 1%. Average flow grade rose from 1.5 to 1.9 after UCA and to 2.8 after PTCA. No vasospasm, atrioventricular block or perforation was caused by UCA. Angiography demonstrated dissection after PTCA in seven patients, treated in two with a stent. Both UCA and PTCA failed to achieve recanalization in one patient with a thrombotic occluded coronary artery after acute myocardial infarction. In all other patients there were no complications. The results show UCA to be a safe method for removing high-degree coronary artery stenosis or recanalize thrombotic occlusions.