No abstract

Central aortic systolic blood pressure (BP) is an important determinant of cardiac workload and cardiac hypertrophy. The relationship of central aortic systolic BP and brachial BP varies depending on the stiffness of blood vessels. It is not certain whether the different drug classes affect the brachial and aortic systolic BP in a similar manner. In a double-blind crossover study, we measured the effects of the four major drug classes compared with placebo on central aortic pressure. Central aortic pressure and various indices were determined using the Sphygmo Cor apparatus. The study was undertaken in patients aged 65 to 85 years with systolic BP >150 mm Hg at study entry. Results are reported for 32 patients who had satisfactory applanation tonometry in all five periods. Calcium channel blockers and diuretics caused a greater fall in brachial artery systolic BP than angiotensin-converting enzyme (ACE) inhibitors or beta-blocking drugs. On placebo, central aorta augmentation pressure and index were 23 mm Hg and 33.3%; on ACE inhibitors the values were 18 mm Hg and 30%; on beta-blockers, 26 mm Hg and 38.5%; on calcium channel blockers, 16 mm Hg and 28%; and on diuretics, 17 mm Hg and 28.8%. The augmentation pressure on beta-blocking drugs was greater than on the other three drug classes (P <.05), and augmentation pressures on ACE inhibitors, calcium channel blockers, and diuretics were less than on placebo (P <.05). The lowest central aortic pressures were achieved with calcium blocking drugs and diuretics. Therapy based on brachial artery recordings may thus overestimate the effect of beta-blocking drugs on central aortic systolic BP and underestimate the effectiveness of ACE inhibitors and calcium blocking drugs. The clinical importance of this discrepancy needs to be evaluated.

Carvedilol is an arylethanolamine that is a racemic mixture of 2 enantiomers. The S-(-)-enantiomer has beta-adrenoceptor blocking activity, while the racemate also has alpha 1-receptor blocking activity due to the activity of the R-(+)-enantiomer. The drug is rapidly absorbed and undergoes extensive first-pass metabolism in the liver. It reaches a peak concentration 1 to 2 hours postdose and has an elimination half-life of about 4 to 7 hours. Absorption is delayed by food. The drug is highly lipophilic and is highly protein bound. The drug is metabolised by the liver, with some metabolites having biological activity. The pharmacokinetic profile is not altered in the elderly or in patients with renal disease. However, bioavailability of the oral medication is greatly increased in patients with liver disease. Carvedilol lowers blood pressure as a result of its beta-blocking and vasodilatory activity. The reduction in blood pressure is similar to that achieved with other antihypertensive drugs, and there are no adverse effects on renal or cerebral blood flow. Carvedilol has been used in small numbers of patients with cardiac failure. It reduces left ventricular hypertrophy and has no significant adverse metabolic effects.

Abstract-Central arterial waveforms and related indices of large artery properties can be determined with relative ease.This would make them an attractive adjunct in the risk stratification for cardiovascular disease. Although they have been associated with some classical risk factors and the presence of coronary disease, their prospective value in predicting cardiovascular outcomes is unknown. The present study determined the relative predictive value for cardiovascular disease-free survival of large artery properties as compared with noninvasive brachial blood pressure alone in a population of elderly female hypertensive subjects. We measured systemic arterial compliance, central systolic pressure, and carotid augmentation index in a subset of female participants in the Second Australian National Blood Pressure Study (untreated blood pressure 169/88Ϯ12/8 mm Hg). There were a total of 53 defined events during a median of 4.