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Coronary vasodilator reserve in untreated and treated hypertensive patients with and without left ventricular
I Antony1, A Nitenberg, J M Foult
1Service d'Explorations Fonctionnelles, Institut National de la Santé de la Recherche Médicale Unité 251, Centre Hospitalier, Universitaire Xavier Bichat, Paris, France.
Insights
Hypertension impairs coronary reserve, especially with left ventricular hypertrophy. Effective treatment normalizes coronary reserve in patients without persistent hypertrophy, but impairment remains if hypertrophy persists.
Area of Science:
- Cardiology
- Hypertension Research
- Coronary Physiology
Background:
- Coronary reserve is compromised in hypertensive patients with left ventricular hypertrophy.
- Elevated basal coronary resistance is noted in hypertensive patients without left ventricular hypertrophy.
- Left ventricular hypertrophy (LVH) is a key concern in managing hypertension.
Purpose of the Study:
- To compare coronary reserve in treated hypertensive patients with and without LVH.
- To evaluate coronary reserve in untreated hypertensive patients.
- To assess the impact of hypertension treatment on coronary reserve.
Main Methods:
- Coronary reserve measured using coronary Doppler catheter and intracoronary papaverine.
- Study included 16 control subjects and 37 hypertensive patients.
- Patients categorized into untreated (with/without LVH) and treated (with/without persistent LVH) groups.
Main Results:
- Coronary reserve was reduced in untreated patients with normal myocardial mass and those with LVH.
- Markedly diminished coronary reserve was observed in untreated patients with LVH and treated patients with persistent LVH.
- Treated patients without persistent LVH showed coronary reserve comparable to controls.
Conclusions:
- Coronary microvasculature abnormalities may precede LVH in hypertension.
- Effective hypertension treatment normalizes coronary reserve when LVH is absent or resolved.
- Persistent LVH despite treatment is associated with significant coronary reserve impairment.
Objectives:
This study was initiated to compare the coronary reserve in treated hypertensive patients with and without left ventricular hypertrophy with that in untreated patients.
Background:
Coronary reserve is impaired in hypertensive patients with left ventricular hypertrophy and normal coronary arteries. Moreover, basal coronary resistance is elevated in hypertensive patients without left ventricular hypertrophy.
Methods:
Coronary reserve was measured with a coronary Doppler catheter before and after a maximally vasodilating dose of intracoronary papaverine (peak/rest flow velocity ratio) in 16 control subjects and 37 hypertensive patients with normal epicardial coronary arteries. Among 20 untreated hypertensive patients, myocardial mass was increased in 11 (group 2a) and normal in 9 (group 2b). Seventeen patients had been treated effectively for at least 1 year; nine (group 3a) had persistent left ventricular hypertrophy, and eight (group 3b) had no left ventricular hypertrophy before treatment. Left ventricular volumes and ejection fraction were normal in all groups.
Results:
Coronary reserve was moderately reduced in group 2b (3.5 +/- 0.6 vs. 5.2 +/- 0.8 in control subjects, p < 0.001) and markedly diminished in groups 2a and 3a (2.5 +/- 0.5 and 2.7 +/- 0.4, respectively; all p < 0.001 vs. control subjects). In group 3b, coronary reserve was comparable to that of control subjects (5.1 +/- 1.4).
Conclusions:
The reduction in coronary reserve observed in untreated hypertensive patients with normal myocardial mass suggests that structural abnormalities of the coronary microvasculature may occur before left ventricular hypertrophy. Treated patients with normal mass before treatment had a coronary reserve comparable to that of normotensive control subjects, whereas normalization of arterial pressure with persistent left ventricular hypertrophy was associated with a marked impairment of coronary reserve.