Aim: to assess additive diagnostic value of simultaneous evaluation of coronary flow reserve (CFR) in the left anterior descending (LAD) artery and posterior descending artery (PDA) during dipyridamole stress echocardiography (stress-Echo) for detection of LAD and PDA stenoses >50%.
Methods: 108 in-patients (mean age 50+/-11 years) with cardiac chest pain underwent dipyridamole stress-Echo with ECG-analysis, wall motion analysis by 2-dimentional imaging (2D) and coronary flow reserve (CFR) evaluation in both LAD and PDA by pulse-wave Doppler. The 2D test was considered positive when more or equal 2 segments demonstrated wall motion abnormalities. CFR was calculated as ratio of hyperemic to basal peak diastolic blood flow velocity. CFR <2.0 was considered reduced. Coronary angiography was performed within one week after stress-Echo.
Results: 34 of 97 patients with CFR in the LAD and wall motion in the LAD territory had LAD stenosis >50%, and 22 of 90 patients with evaluated CFR in the PDA and wall motion in the RCA territory had RCA stenosis >50%. Thus stenosis >50% was detected in 56 of 187 evaluated LAD and RCA. The 2D test and ECG results were positive for 35 arterial territories, reduced CFR - for 48 arteries. With combined evaluation of ECG, 2D test and CFR, accuracy was not significantly higher (80% for ECG+2D test, 82% for CFR and 80% for combined test) but sensitivity and negative predictive value increased (sensitivity: 63% for ECG+2D test, 86% for CFR and 91% for combined test; negative predictive value: 85% for ECG+2D test, 93% for CFR and 95% for combined test).
Conclusion: Assessment of CFR in both LAD and PDA is feasible for majority of patients and can increase sensitivity and negative predictive value of dipyridamole stress-Echo for the detection.