Detection of coronary restenosis aftercoronary angioplasty by contrast-enhanced transthoracic echocardiographic Doppler assessment of coronary flow velocity reserve

This study sought to evaluate the diagnostic potential of contrast-enhanced transthoracic echocardiography (CE-TTE) during adenosine infusion, a noninvasive method for evaluating coronary flow reserve (CFR), in detecting restenosis after successful percutaneous transluminal coronary angioplasty (PTCA). Restenosis is the most important limitation of PTCA, and CFR can be impaired in patients with angiographically documented significant coronary stenosis. We performed 6 ± 2 months of follow-up of 53 patients after successful elective PTCA in the left anterior descending coronary artery (LAD). Coronary angiography was performed at the end of the planned follow-up period or even before, if clinically indicated. Thus, of the 53 patients, a total of 63 angiographic studies were performed; CE-TTE assessment of CFR was achieved before each of the 63 angiographic studies. Coronary angiography revealed the presence of restenosis (defined as >50% stenosis at a previous PTCA site) in 32 angiographic examinations (group A) and no coronary restenosis in the remaining 31 examinations (group B). Coronary flow reserve was significantly reduced in group A compared with group B (1.65 ± 0.5 vs. 3.17 ± 0.8, p ≤ 0.001). A noninvasive CFR value ≤2 was 93% specific and 78% sensitive for detecting significant restenosis, with positive and negative diagnostic accuracies of 92% and 80%, respectively. Noninvasive CFR assessment by CE-TTE is an accurate method of monitoring significant restenosis in the LAD when following up patients submitted to elective PTCA.