Abstract 5518: Abnormal Coronary Flow Reserve is Related to Impairment of Left Ventricular Function During Adenosine Stress Echocardiography in Untreated Hypertensive Patients
Objective: Coronary microcirculation is disturbed in hypertensive patients. We investigated the effects of coronary flow reserve (CFR) on the response of Left Ventricular (LV) systolic and diastolic function as assessed by Tissue Doppler Imaging during adenosine stress echocardiography in never-treated hypertensive patients.
Methods: We studied 43 patients (mean age: 53±12 years), with untreated arterial hypertension (clinic blood pressure >140/90 mmHg and >125/80 mmHg in 24hour ambulatory BP monitoring) by adenosine stress echocardiography and 22 healthy controls matched for sex, age and atherosclerotic factors. We measured:
time integral (VTI-Vd) of diastolic (Vd) coronary blood flow velocity by transthoracic Doppler echocardiography of the LAD
Ratio of VTI-Vd after adenosine infusion (140 μg/kg/min) to VTI-Vd at baseline to assess CFR
E and A doppler, Sm, Em, Am lateral mitral annulus velocities with TDI, Em/Am ratio and E/Em ratio before and during adenosine infusion to assess LV systolic and diastolic function,
the percent % changes of the measured indices between baseline and peak adenosine infusion.
Results: All patients had normal baseline ejection fraction. Compared to controls, hypertensives had lower CFR (2.3±0.7 vs. 2.9±0.9, p=0.03). At baseline, hypertensives compared to controls, had lower Em/Am ratio (0.9±0.3 vs. 1.3±0.4, p=0.002), Sm (8.7±1.7 vs. 9.7±2.6, p=0.07), Em (10.1±2.8 vs 12.1±3.5, p=0.03) and higher Am (11.1±2.5 vs. 9.5±2.0, p=0.03). At peak adenosine infusion there were an increase in Sm, Em and Am in all patients (p<0.05). Furthermore a decreasing CFR was associated with a decreasing Em (r= 0.46, p=0.05), Em/Am (r=0.49, p=0.048) and increasing E/Em (r=−0.4, p=0.04). A reduced CFR was related with a smaller % increase of Sm (r= −0.40, p=0.049), % increase of Em (r=− 0.5, p=0.033) and higher % increase of E/Em (r=−.42, p=0.04) at peak stress. Patients with CFR<2.5 (n=28), compared to those with CFR≥2.5 had lower % change of Sm (27±20% vs. 51±34% p=0.04), % change of Em (8±3% vs. 46 ±3%, p=0.05) and higher % increase of E/Em (24±3% vs −1±2%, p=0.04).
Conclusions: An abnormal response of LV function during adenosine stress echocardiography is related with impaired CFR in untreated hypertensive patients.