The influence of left ventricular geometry on coronary vasomotion in patients with essential hypertension

Left ventricular (LV) geometry and dipping state are determinants of LV mass reduction with angiotensin-converting enzyme inhibitor antihypertensive treatment

OBJECTIVES

Left ventricular hypertrophy is a major risk predictor in hypertensive patients and its regression is beneficial in terms of prognosis. The aim of this observational, open-labeled study was to investigate the effect of left ventricular geometry and dipping pattern on left ventricular mass reduction after chronic treatment with angiotensin-converting enzyme inhibitors, in a large population of hypertensive patients.

METHODS

We evaluated untreated patients with mild to moderate essential hypertension, before and 6 months after treatment with angiotensin-converting enzyme inhibitor monotherapy or angiotensin-converting enzyme inhibitor-low-dose thiazide combination. Left ventricular mass index, relative wall thickness and geometry pattern were derived from echocardiography. Dipping state was determined with 24-h ambulatory blood pressure monitoring at enrollment.

RESULTS

Overall, left ventricular mass index decrease in the 1400 patients (mean age 52.5 years) who completed the study was 12.9% of baseline value (P<0.00001). After adjusting for pretreatment value, left ventricular mass index reduction was similar with all angiotensin-converting enzyme inhibitors used [P= NS (not significant)], but it was higher in nondippers than dippers (14.1 vs. 12.3%, P<0.0001) and in patients with than without baseline left ventricular hypertrophy (14.6 vs. 11.3%, P<0.0001). We observed a stepwise augmentation of left ventricular mass index decrease with worsening left ventricular geometry (P<0.001). In multivariable analysis, impaired left ventricular geometry and blunted nocturnal blood pressure fall before treatment were independent predictors of a high left ventricular mass index reduction after treatment, independent of blood pressure fall, pretreatment left ventricular mass index, and other potential confounders.

CONCLUSION

In essential hypertension, left ventricular geometry and dipping state are independent determinants of left ventricular mass reduction with angiotensin-converting enzyme inhibitor treatment. All angiotensin-converting enzyme inhibitors are efficient in decreasing left ventricular mass.

Coronary flow reserve in hypertensive patients with appropriate or inappropriate left ventricular mass

OBJECTIVE

To assess the association between coronary flow reserve (CFR) and levels of left ventricular mass (LVM) exceeding the compensatory needs in arterial hypertension. DESIGN, SETTINGS AND PATIENTS: The association between the excess of LV mass and CFR was assessed in a population of 40 consecutive hypertensive outpatients free of coronary heart disease, 22 with appropriate and 17 with inappropriately high LVM (i.e. LVM exceeding 128% of the value predicted by sex, stroke work and height in m(2.7)). The CFR (the ratio between dipyridamole and basal diastolic peak velocity) of the distal left anterior descending artery was measured by transthoracic Doppler echocardiography.

RESULTS

Patients with inappropriate LVM had similar age, body mass index (BMI), baseline blood pressure (BP) and coronary velocities, but lower LV systolic function, post-dipyridamole diastolic peak velocities (P < 0.05) and lower CFR (P < 0.002) than patients with appropriate LVM. CFR was negatively related to the extent of the excess of LVM (beta = -0.44, P < 0.005), independently of potential combined effect of age, BMI and post-dipyridamole diastolic BP. Impairment of CFR (i.e. < 2) was better discriminated by identification of clear-cut inappropriate LVM (P < 0.004) than by the presence of LV hypertrophy (i.e. LV mass index > or = 51 g/m(2.7); P = 0.057).

CONCLUSIONS

In hypertensive patients free of coronary artery disease, the degree of reduction in CFR is associated with the excess of LVM beyond the values compensatory for individual haemodynamic load. This relation is also independent of the presence of LV hypertrophy.

Influence of wall stress and left ventricular geometry on the accuracy of dobutamine stress echocardiography

OBJECTIVE

The goal of this study was to determine whether wall stress at rest and during stress could explain the influence of left ventricular (LV) morphology on the accuracy of dobutamine stress echocardiography (DSE).

BACKGROUND

The sensitivity of DSE appears to be reduced in patients with concentric remodeling, but the cause of this finding is unclear.

METHODS

We studied 161 patients without resting wall motion abnormalities who underwent DSE and coronary angiography. Patients were classified into four groups according to relative wall thickness (normal <0.45) and LV mass (normal </=131 g/m(2) in men and </=100 g/m(2) in women): normal geometry, concentric remodeling, concentric hypertrophy, and eccentric hypertrophy. Significant coronary artery disease was defined as >/=50% stenosis. Circumferential (cESS) and meridional end-systolic wall stress (mESS) were calculated at rest and peak DSE.

RESULTS

Both false-negative and false-positive results for DSE were present in 35 patients (22%). The accuracy of DSE in patients with concentric remodeling (61%) was lower than that in patients with normal geometry (85%, p < 0.05) or concentric hypertrophy (86%, p < 0.05), but the accuracy with eccentric hypertrophy (64%, p < 0.05) was lower than with concentric hypertrophy. Patients in lowest quartile of cESS and mESS at peak had significantly lower sensitivity and accuracy than those in the highest quartile. A reduced cESS at peak (p = 0.012), presence of concentric remodeling (p = 0.044), and eccentric hypertrophy (p = 0.012) were significant predictors of both false-negative and false-positive results for DSE.

CONCLUSIONS

The accuracy of DSE is influenced by the LV geometric pattern and peak wall stress.

Influence of left ventricular geometry on regional systolic and diastolic function in patients with essential hypertension

OBJECTIVE

In essential hypertension, especially in concentric hypertrophy, global diastolic function is impaired. But, whether the left ventricular (LV) geometric pattern influences regional systolic and diastolic function or not, is unknown. This study was aimed to evaluate the influence of left ventricular geometric pattern on regional systolic and diastolic function in hypertensive patients.

DESIGN

Ninety untreated mild to moderate hypertensive patients were studied. M-mode parameters, standard Doppler and PW tissue Doppler indices were measured. Patients were divided into four groups according to left ventricular mass index and relative wall thickness: normal geometry (n = 16), concentric remodeling (n = 16), eccentric hypertrophy (n = 32) and concentric hypertrophy (n = 26).

RESULTS

Age, gender, body mass index, systolic and diastolic blood pressure were similar among groups. E/A ratio was significantly lower in the concentric hypertrophy group compared with the normal geometry group. Em velocity and Em/Am ratio in basal septum and Em velocity in basal inferior were statistically lower in the concentric hypertrophy group compared with the normal geometry group. In the concentric hypertrophy group, the number of segments with diastolic dysfunction was significantly higher compared with the normal geometry group. LV ejection fraction and regional S velocity could be compared among groups.

CONCLUSION

LV regional diastolic function is being impaired in concentric hypertrophy. LV regional systolic function does not show a difference according to the LV geometric pattern.