Changes in left ventricular dimensions and systolic function in 100 mildly hypertensive men during one year's treatment with atenolol vs. hydrochlorothiazide and amiloride (Moduretic): a double-blind, randomized study

Regression of Left Ventricular Mass by Antihypertensive Treatment

Blood pressure–lowering therapy reduces left ventricular mass, but the question of whether differences exist among drug classes has not been fully resolved. Our aim was to compare the effects of diuretics, β-blockers, calcium channel blockers, angiotensin-converting enzyme inhibitors, and angiotensin receptor blockers on left ventricular mass regression in patients with hypertension on the basis of prospective, randomized comparative studies. We performed meta-analyses, involving pooled pairwise comparisons of the drug classes and of each class versus other classes statistically combined, and meta-regression analyses to identify the determinants of the regression. The 75 relevant publications involved 84 pairwise comparisons and 6001 patients. Regression of left ventricular mass was significantly less ( P =0.01) with β-blockers (9.8%) than with angiotensin receptor blockers (12.5%), but none of the other analyzable pairwise comparisons between drug classes revealed significant differences ( P >0.10). In addition, β-blockers showed less regression than the other 4 classes statistically combined ( P <0.01), and regression was more pronounced with angiotensin receptor blockers versus the others ( P <0.01). In multivariable meta-regression analysis on all of the treatment arms, β-blocker treatment was a significant and negative predictor of the regression (−3.6%; P <0.01), but this was not the case for the other drug classes, including angiotensin receptor blockers. In conclusion, β-blockers show less regression of left ventricular mass, whereas angiotensin receptor blockers may induce larger regression. The inferiority of β-blockers appears to be more convincing than the superiority of angiotensin receptor blockers.

Hypertensive left ventricular hypertrophy: pathophysiology, assessment and treatment

Left ventricular hypertrophy (LVH) is a strong predictor of cardiovascular morbidity and mortality. LVH is associated with coronary events, and there is an association between cerebrovascular disease and increased left ventricular mass (LVM). Experimental studies have elucidated the importance of non-myocytic cells inducing increased perivascular and interstitial fibrosis along with thickening of the media of intramyocardial coronary arteries in hypertensive LVH. M-mode echocardiography is the most accepted standard for the diagnosis and quantification of LVH, but some controversies exist regarding the ideal methodology for serial assessment of LVM. It is still a matter of debate whether 2-dimensional echo measurements represent a more accurate method. Hopefully, both the introduction of 3-dimensional echo and new Doppler techniques can provide more accurate measurements of LVM and additional information on changes in myocardial fibrosis and stiffness. Experimental studies have shown that normalization of hypertensive myocardial and coronary artery remodelling take place with drugs like angiotensin converting enzyme (ACE)-inhibitors and calcium antagonists. Two meta-analyses suggest that ACE-inhibitors may be the most efficient drugs in reducing LVM, but a clinical correlate to this assumption is at present not available. There are some indications that regression or progression of LVH assessed by ECG and echocardiography may in fact be related to the incidence of cardiovascular events. But large-scale controlled studies of various treatment regimens are still needed to establish whether drug induced regression can improve the prognosis of hypertensive LVH independent of the antihypertensive effect.

Left ventricular end-diastolic dimensions measured at the P wave and Q wave during a randomized, double-blind one-year follow-up study comparing the effect of atenolol vs. hydrochlorothiazide + amiloride on blood pressure in men with mild to moderate hypertension

Echocardiographic measurement of left ventricular (LV) end-diastolic dimensions and mass (M) were made at baseline, at 3 and 12 months of a randomized trial comparing atenolol 50/100 mg od. and hydrochlorothiazide 25/50 mg+amiloride 5 mg od. (co-amiloride) in 100 men with mild to moderate hypertension. Data from 48 subjects controlled adequately on drug monotherapy and completing 12 months treatment are reported (31 randomized to atenolol and 17 to co-amiloride). Left ventricular mass was measured with the Penn convention at the R and P wave respectively. A significant reduction of LVM was noted after one year in both groups (p < 0.05) when measured at the R, but not at the P wave. Measurements according to American Society of Echocardiography (ASE method) at the Q wave revealed a significant reduction of LV wall thickness (p < 0.01) and an increase of LV internal diameter (p < 0.01) with atenolol. In the co-amiloride group non-significant reductions of LV dimensions were observed. Principally similar changes were observed with measurements at the P wave (National Institute of Heart method) in both groups, but LV wall thickness was greater and LV internal diameter smaller than at the Q wave. With similar effect on LVM, the mechanisms in reducing LVM were different between the two drugs. Left ventricular dimensions differed when assessed with the two methods applied, stressing the need for careful standardization in relation to the cardiac cycle in serial echocardiographic measurements.

Haemodynamic findings and response rates to beta-blocker--and diuretic monotherapy in mild and moderate hypertension. A one year randomized, double blind study in 100 men

In a randomized double blind study 100 men (mean age 46 (22-64) years) with mild to moderate hypertension were followed every 3rd month for one year. Fifty were randomized to atenolol 50 mg and 50 to hydrochlorothiazide 25 mg+amiloride 5 mg (co-amiloride) once daily. The doses were doubled at 3 or 6 months if diastolic blood pressure (DBP) remained > or = 95 mmHg. If DBP was > or = 95 mmHg even at 6 or 9 months, patients were classified as non-responders, and nifedipine 20 mg b.i.d. was added. After one year 31/50 randomized to atenolol and 17/50 randomized to co-amiloride had responded to monotherapy (p < 0.05). Neither clinical findings nor haemodynamic measurements by Doppler at baseline could distinguish between co-amiloride responders and non-responders. Conversely, non-responders to atenolol as compared with atenolol responders had higher body weight (p = 0.02), higher systolic BP (p = 0.03), higher DBP (p = 0.009), stroke volume (p = 0.04), and cardiac output (p = 0.0002) combined with lower total systemic vascular resistance (p = 0.02). This suggests that some were apparent non-responders due to too low dosing of atenolol rather than true non-responders. Measurements of haemodynamics may be of importance in the assessment of optimal antihypertensive therapy according to baseline and follow-up haemodynamic aberrations.