Left ventricular remodeling impairs coronary flow reserve in hypertensive patients.

BACKGROUND

In arterial hypertension, changes in both left ventricular mass and geometry may occur. Concentric left ventricular remodeling (i.e. an increased wall thickness relative to end diastolic diameter) has been implicated as an independent cardiovascular risk factor in hypertensive patients. The influence of concentric remodeling on the coronary microcirculation is not known.

OBJECTIVE

To investigate the impact of left ventricular geometry on coronary flow reserve in patients with arterial hypertension and angiographically normal coronary arteries.

METHODS

Following exclusion of coronary artery disease by cardiac catheterization, coronary flow reserve (dipyridamole, 0.5 mg/kg body weight intravenously; argon gas-chromatographic method) was measured in 49 patients with arterial hypertension and in six age-matched controls. Hypertensive patients were grouped by echocardiographic findings according to left ventricular mass and relative left ventricular wall thickness (i.e. left ventricular posterior wall plus septal thickness divided by end diastolic diameter): seven patients had normal left ventricular mass and geometry, 19 had eccentric hypertrophy (i.e. normal relative wall thickness but increased mass), concentric remodeling (i.e. normal mass but increased relative wall thickness) was present in nine patients, and 14 patients had concentric hypertrophy.

RESULTS

There was a marked reduction in coronary flow reserve in all hypertensive groups as compared with control values (4.2 +/- 0.5). Within the hypertensive subgroups, the coronary flow reserve was differentially reduced in the following rank order: concentric remodeling (2.0 +/- 0.7) approximately concentric hypertrophy (2.3 +/- 0.8) < eccentric hypertrophy (2.9 +/- 0.6) mu normal geometry (2.7 +/- 0.4). Multi-factorial regression analysis showed that the relative wall thickness but not left ventricular mass was independently linked to the coronary flow reserve.

CONCLUSIONS

Concentric left ventricular remodeling is an independent predictor of the coronary flow reserve in hypertensive patients with chest pain and normal coronary angiogram. The impairment of the coronary microcirculation may contribute to the excess cardiovascular event rate associated with hypertensive concentric left ventricular remodeling.