Aims: Coronary microcirculation is disturbed in hypertensive patients. We investigated the association of coronary flow reserve (CFR) with the response of left ventricular (LV) function as assessed by tissue Doppler imaging (TDI) during adenosine stress echocardiography in never-treated hypertensive patients.
Methods and results: We studied 90 hypertensive patients and 30 control subjects, matched for age and sex, by adenosine stress echocardiography. We measured: (i) CFR, E and A Doppler, S', E', A' mitral annulus velocities with TDI, as well as the E'/A' ratio and the E/E' ratio before and during adenosine infusion (ii) the %changes of the measured indices between baseline and adenosine infusion. After adenosine infusion, there was an increase in S', E', and A' in all patients and controls (P < 0.05). Compared with controls and patients with CFR ≥ 2.5, patients with CFR <2.5 showed a smaller increase in S' (28.6 vs. 30.0 vs. 11.1%, F for interaction = 14.592) and E' (33.3 vs. 33.3 vs.1.5%, F = 28.927) as well as a decrease in E'/A' (9.2 vs. 6.4% vs. -20.0%, F = 5.128) and an increase in E/E' (-6.1 vs. -1.6 vs. 30.5%. F = 12.780) after adenosine infusion (P < 0.05 for all comparisons). CFR was independently related to %changes of TDI parameters (regression coefficient b = 0.576 for S'; b = 0.517 for E'; b = 0.473 for E'/A'; b = -0.520 for E/E', respectively, P < 0.001). By the receiver operating curve, a CFR <2.5 predicted the median changes of all measured TDI markers, with a sensitivity and specificity over 70% (AUC >75%, P < 0.05).
Conclusion: An abnormal response of the LV longitudinal function during adenosine stress echocardiography is related to impaired CFR in untreated hypertensive patients.