Augmentation of myocardial blood flow in hypertensive heart disease by angiotensin antagonists: a comparison of lisinopril and losartan.
OBJECTIVE
The goal of this study was to compare myocardial perfusion reserve (MPR) before and after long-term treatment with lisinopril and losartan in patients with hypertension and left ventricular hypertrophy (LVH).


BACKGROUND
Studies have suggested that treatment with angiotensin-converting enzyme inhibitors (ACEIs) improves MPR in patients with hypertension by potentiating endogenous bradykinins. Because angiotensin receptor blockers (ARBs) lack a direct effect on bradykinins, we hypothesized that they may not improve MPR.


METHODS
We measured pre- and post-treatment myocardial blood flow (MBF) by positron emission tomography in 17 patients (lisinopril: 9 patients, losartan: 8 patients) with hypertension and LVH at baseline and after coronary vasodilation with intravenous dipyridamole. In addition, we measured rest and hyperemic blood flow in eight normotensive controls.


RESULTS
Post-treatment maximal coronary blood flow and MPR in the lisinopril group increased significantly compared with pretreatment values (3.5 +/- 1.2 vs. 2.6 +/- 1.1 ml/min/g, p = 0.02; 3.7 +/- 1.1 vs. 2.4 +/- 1 ml/min/g, respectively, p = 0.002, respectively). Post-treatment hyperemic flow in the patients treated with lisinopril was not significantly different from corresponding measurements in controls (3.5 +/- 1.2 vs. 3.9 +/- 1 ml/min/g, respectively, p = NS). In the patients treated with losartan, there was no difference between pre- and post-treatment MBF values and MPR.


CONCLUSIONS
Myocardial perfusion reserve and maximal coronary flow improved in asymptomatic patients with hypertension-induced LVH after long-term treatment with lisinopril but not with losartan. Thus, ACEIs, but not ARBs, might be effective in repairing the coronary microangiopathy associated with hypertension-induced LVH.
Saint Francis Hospital, Non-Invasive Laboratory, Roslyn, New York 11576, USA. ooa2@columbia.edu
Olakunle O
OO
Akinboboye
Ru-Ling
RL
Chou
Steven R
SR
Bergmann
D000328:Adult; D000804:Angiotensin II / Q000037:antagonists & inhibitors; D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D003326:Coronary Circulation / Q000187:drug effects*; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000503:physiopathology; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D017379:Hypertrophy, Left Ventricular / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology*; D017706:Lisinopril / Q000494:pharmacology* / Q000627:therapeutic use; D019808:Losartan / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D014055:Tomography, Emission-Computed
D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D000804:Angiotensin II; D017706:Lisinopril; D019808:Losartan