Myocardial perfusion and angioplasty. Comparison of myocardial contrast echocardiography and scintigraphy.

Objectives: To estimate the efficacy of myocardial contrast echocardiography (MCE) by harmonic power imaging (HPI), in evaluation of perfusion in one-vessel coronary disease treated by angioplasty, using myocardial scintigraphy as gold standard. Study design: Prospective comparative study. Setting: Ambulatory. Population: We included 33 patients (pts), aged 53.5 ′ 9 years, 27 male. Inclusion criteria: pts with one-vessel coronary disease (≥70% stenosis), with indication for angioplasty; sinus rhythm; good echocardiographic window with harmonic imaging. Exclusion criterion: previous myocardial infarction. Methods: All patients underwent myocardial scintigraphy and HPI together with stress echocardiography, both followed by angioplasty (stenting in ten). HPI and myocardial scintigraphy were repeated, in all patients, at three months after intervention. Ten patients were re-assessed by coronary angiography for ischemia on the scintigraphic study. For the HPI exam, Levovist was selected as contrast and dipyridamole as stress agent (0.56 mg/kg). Perfusion was assessed visually and classified by HPI and scintigraphy studies as: 1 (normal), 2 (reduced), or 3 (absent). For analysis, the left ventricle was divided into 16 segments. Results: Of the 43 coronary angiograms performed (ten at three months after angioplasty), 38 showed 70% stenosis, none occlusive or subocclusive. We analyzed 1056 left ventricle segments, from 66 HPI and myocardial scintigraphy studies (before and after angioplasty). Analysis was impossible or doubtful in 4.9%. Baseline and stress HPI detected 216 perfusion abnormalities. Global concordance between the segmental perfusion score obtained by HPI and scintigraphy was 66.2%, which became 76.3% when two groups were considered: a) score 1 b) score 2 and 3 together. In comparison with scintigraphy, HPI sensitivity for detection of perfusion abnormalities was 79.3% (higher for anterior septum, anterior and lateral wall) and specificity was 91.4% (higher for septum, inferior wall and apical segments). HPI correctly identified the location of coronary stenosis in 73.5% of patients. Conclusions: In our study, HPI was a feasible and promising method for assessment of perfusion in one-vessel coronary disease and chronic ischemia. In comparison with myocardial scintigraphy, a high concordance for perfusion score was found, as well as high sensitivity and specificity for detection of perfusion abnormalities.