Sensitivity Increase of Dipyridamole Echo-Stress with Simultaneous Determination of Contractility and Coronary Flow Reserve of the Anterior Descending Coronary Artery by Transthoracic Doppler Echocardiography

pp 683-696

Abstract

Objectives

To evaluate the feasibility and safety of the determination of the coronary flow velocity reserve(CFR) in the left anterior descending coronary artery (LAD) territory by transthoracic Doppler echocardiography (TTE) during dipyridamole echo-stress (Dip), and to find out if there is some additional information to the simultaneous analysis of the regional left ventricular contractility.

Material and methods

One hundred and seventy consecutive studies were performed in unselected patients, mean age 64.4 ±10 years old (93 men). Patients with revascularization procedures or prior anterior AMI or severe (akinesis -diskinesis) baseline apical, septal and/or anterior wall motion abnormalities were excluded.The betablocker medication was not interrupted. The diastolic coronary flow velocity was continuously monitored by pulsed-wave Doppler at theLAD, at rest and during the hyperemic phase induced by 0.84 mg/kg of dipyridamole (Dip) for 4 minutes, plus 1 mg atropine. The CFR was calculated as the ratio between the maximal (MCFV) and the basal velocity (BCFV). The results of the patients with a non significant LAD (< 70%) stenosis (group A) were compared with the remaining group disease (>_ 70%) lesion (group B).

Results

The CFR feasibility was 97.6% (166/170 patients), without severe side effects. Thirty-nine patients who met the inclusion criteria and an angiographic study within the week after the Dip echo-stress study with simultaneous CFR measurement provided the following findings: in group A (24 patients with LAD stenosis < 70%), all the 24 patients had a normal contractile response in the territory of the LAD during our standard Dip-atropine stress procotol (specificity of 100%), and 4 patients presented an abnormal CFR (specificity 83.3%) (p =0.1).In group B (15 patients with LAD stenosis >_70%) new apical, septal and/or anterior wall motion abnormalities were identified in only 10 patients (sensitivity 66.6%) while a restricted CFR was determined in all the 15 patients (sensitivity of100%) (p < 0.02) .

Conclusions

The simultaneous coronary flow reserve and contractility assessment by transthoracic Doppler echocardiography during dipyridamole echo-stress allows to increase the sensitivity of the test significantly. The proposed methodology was highly feasible and safe, with favorable implications on the cost-effectiveness profile of the test.