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Normalization of abnormal coronary vasomotion by calcium antagonists in patients with hypertension
J Frielingsdorf1, C Seiler, P Kaufmann
1Cardiology, University Hospital, Zürich, Switzerland.
Insights
Hypertension impairs coronary artery vasomotion during exercise. Calcium antagonists improve exercise-induced coronary vasodilation in hypertensive patients with coronary artery disease, potentially correcting endothelial dysfunction.
Area of Science:
- Cardiovascular Medicine
- Clinical Physiology
- Pharmacology
Background:
- Endothelial dysfunction and impaired vasodilation are noted in hypertension.
- Coronary artery disease (CAD) patients often exhibit endothelial dysfunction.
Purpose of the Study:
- To assess coronary vasomotor response to exercise in CAD patients with and without hypertension.
- To determine the impact of calcium antagonists on coronary vasomotion during exercise in these patients.
Main Methods:
- Biplane quantitative coronary arteriography evaluated luminal area changes in 79 CAD patients during exercise.
- Patients were grouped based on hypertension status and calcium antagonist pretreatment.
- Coronary vasomotor response was assessed at rest, during exercise, and after nitroglycerin.
Main Results:
- Hypertensive patients without calcium antagonists showed blunted vasodilation in normal arteries and vasoconstriction in stenotic arteries during exercise.
- In contrast, hypertensive patients pretreated with calcium antagonists exhibited normal coronary vasodilation in both normal and stenotic vessels during exercise.
- Mean aortic pressure was higher in hypertensive groups compared to normotensive groups.
Conclusions:
- Hypertension is associated with abnormal coronary vasomotion during exercise, characterized by reduced vasodilation and enhanced vasoconstriction.
- Calcium antagonists effectively normalize exercise-induced coronary artery responses in hypertensive CAD patients.
- These findings suggest calcium antagonists may mitigate endothelial dysfunction-related exercise impairment in hypertensive individuals.
Background:
Endothelial dysfunction with a loss of endothelium-dependent vasodilation has been reported in patients with arterial hypertension. The purpose of the present study was to evaluate coronary vasomotor response to dynamic exercise in patients with coronary artery disease with and without arterial hypertension and to determine the effect of calcium antagonists on coronary vasomotion.
Methods And Results:
Cross-sectional areas of a normal and a stenotic coronary vessel segment were examined in 79 patients with coronary artery disease at rest and during supine bicycle exercise (Ex). Change in luminal area after acute administration of a calcium antagonist (diltiazem or nicardipine), during exercise, and after sublingual nitroglycerin (percent change compared with rest = 100%) was assessed by biplane quantitative coronary arteriography. Patients were divided into two groups: Group 1 (control) consisted of 48 patients without (normotensive subjects, n = 30; hypertensive subjects, n = 18) and group 2 of 31 patients with (normotensive subjects, n = 15; hypertensive subjects, n = 16) pretreatment with a calcium antagonist immediately before exercise. The groups did not differ with regard to clinical characteristics or hemodynamic data measured during exercise. Mean aortic pressure at rest, however, was significantly increased in hypertensive patients compared with normotensive subjects in group 1 (103 mm Hg versus 92 mm Hg, P < .01) and group 2 (110 mm Hg versus 98 mm Hg, P < .025). In group 1, exercise-induced vasomotor response was significantly different between normotensive and hypertensive patients in normal (+20% versus +1%, P < .003) and stenotic vessels (-5% versus -20%, P < .025). However, in group 2 there was coronary vasodilation in normotensive and hypertensive patients for both normal (delta Ex +23% versus +21%, P = NS) and stenotic vessel segments (+24% versus +26%, P = NS).
Conclusions:
Abnormal coronary vasomotion during exercise can be observed in hypertensive patients with reduced vasodilator response in normal arteries and enhanced vasoconstrictor response in stenotic arteries. Calcium antagonists prevent the abnormal response of normal and stenotic coronary arteries to exercise in hypertensive patients and thus may compensate for endothelial dysfunction with reduced vasodilator response to exercise.