214 Can stress echocardiography with tissue characterization evaluate non-critical coronary stenosis? A validation study against simultaneous measurement of fractional flow reserve

Abstract

Background: Fractional flow reserve (FFR) is accepted as gold standard for the functional assessment of coronary stenosis. The typical marker of acute myocardial ischemia by tissue Doppler echocardiography with strain rate imaging (TDE/SRI) is postsystolic shortening (PSS). The study evaluated different echocardiographic modalities for detection of myocardial ischemia due to non-critical coronary stenosis. Material and methods: We investigated 22 consecutive patients presenting with stable angina, negative exercise tests and coronary 1-vessel disease with 50-75% diameter stenosis. TDE/SRI was performed at baseline and at peak hyperemia during 0.14 mg/kg/min adenosine infusion simultaneously with intracoronary FFR measurements. Angioplasty was carried out if FFR 0.3, with reduced Ss <15%. Results: Pathologic FFR <0.75 was found in 11 patients, who underwent angioplasty. Myocardial contractility reflected by SRs increased during hyperemia only in the patient group with FFR ≥0.75 and decreased markedly during balloon inflation, but its variation was not robust enough to predict pathologic FFR (Fig. 1). PSS was identified in 10 of 11 patients during vessel occlusion, but had a low sensitivity (2 of 11 patients with FFR <0.75) for the more subtle changes during hyperemia. Conclusion: Although TDE/SRI enhances the diagnostic accuracy of adenosine stress echocardiography, it still cannot serve as a reliable noninvasive alternative to FFR for the functional assessment of moderate-to-severe coronary stenosis.