Feasibility of triple imaging vasodilator stress echo in patients with suspected coronary artery disease

Abstract

Background: Regional wall motion abnormalities (RWMA) are the diagnostic cornerstone of stress echo, but the positivity rate hasbeen declining over the last decades. Additional information is obtained with simultaneous assessment of coronary flow velocityreserve (CFVR) on left anterior descending coronary artery and global left ventricular contractile reserve (LVCR) from the systolicpressure/end-systolic volume relationship.Objective: The aim of this study was to assess the feasibility of triple imaging (RWMA + LVCR + CFVR) during dipyridamole stressecho.Methods: We enrolled 40 consecutive patients (30 men; 62±11 years, mean ejection fraction: 62±7%) referred to testing for suspectedcoronary artery disease. All patients underwent dipyridamole (0.84 mg/kg in 6 min) stress echo. LVCR was defined as theratio between peak and rest elastance index (cuff systolic blood pressure/left ventricular end-systolic volume from biplane Simpsonmethod, normal values: > 1.0). CFVR was defined as the ratio between maximal vasodilation and rest peak diastolic flow velocity inthe left anterior descending coronary artery (normal values >2.0).Results: In 40 consecutive patients, interpretable images were obtained in 40/40 patients (100%) for RWMA, 40/40 (100%) for LVCRand 40/40 (100%) for CFVR. The positivity rate was 1/40 (2%) for RWMA, 4/40 (10%) for LVCR, 6/40 (15%) for CFVR and 9/40(22.5%) with any of the three criteria combined. The average additional imaging time at peak stress after completion of RWMA imagingwas 45 seconds for CFVR; no extra-time was required for LVCR. The average off-line analysis time was 30 seconds for RWMA,55 seconds for LVCR, and 15 seconds for CFVR.Conclusions: Triple imaging vasodilator stress echo was highly feasible and non-time consuming. Abnormal values are more frequentlyfound with CFVR and LVCR than with RWMA. Triple imaging might become the new diagnostic standard in stress echo,and a larger scale validation is now ongoing in the Italian Stress echo 2020 multicenter study.