Comparison of the efficacy between hydrochlorothiazide and chlorthalidone on central aortic pressure when added on to candesartan in treatment-naïve patients of hypertension

Abstract

Thiazide-type diuretics are the most commonly used blood pressure (BP)-lowering drug for patients with uncomplicated hypertension. However, it has remained unclear whether hydrochlorothiazide (HCTZ) or chlorthalidone (CTD) shows better improvement in central aortic pressure. We conducted an open-label, randomized, prospective cross-over study with an 8-week active treatment (HCTZ of 25 mg with candesartan of 8 mg or CTD of 12.5 mg with candesartan of 8 mg) with a 4-week washout period (only candesartan during this period). Twenty-eight treatment-naïve patients of hypertension were enrolled (mean age: 50±9 years, male: 44.4%). Central aortic pressure, pulse wave velocity (PWV), augmentation index (AIx) and other BP-derived parameters were measured. After 8 weeks of active treatment, there was no significant difference in changes of central aortic pressure between HCTZ and CTD treatments (Δ=-14±8 vs. -16±7 mm Hg, P=0.645). However, CTD treatment showed a significant reduction in PWV compared with baseline (1321±194 vs. 1439±190 cm s(-1), P=0.007) and HCTZ treatment (Δ=-118±82 vs. Δ=5±72 cm s(-1), P=0.033), whereas HCTZ treatment showed a marginal, but not a significant reduction in AIx compared with baseline. In conclusion, CTD of 12.5 mg is as potent as HCTZ of 25 mg, when combined with candesartan of 8 mg, in lowering central aortic pressure. In addition, CTD treatment resulted in a significant reduction of PWV.

Impact of the augmentation time ratio on direct measurement of central aortic pressure in the presence of coronary artery disease

“…The reason why we could not show a relationship between AI and CAD might have been due to the differences in patient background compared with previous studies. First, the mean augmentation pressure serves as a predictive factor of the presence of CAD, especially in a group with a low augmentation pressure (7-8 mm Hg), 6 whereas the mean augmentation pressure does not serve as a predictive factor in a group with a high augmentation pressure (12-14 mm Hg). 15 The mean augmentation pressure in our study was 20 mm Hg, which was higher than previous studies.…”

“…1-3 Furthermore, central hemodynamic variables, such as augmentation index (AI), are independent predictors of cardiovascular events and mortality. [3][4][5][6][7][8] Recent advances in noninvasive instrumentation to estimate central aortic pressure have allowed for estimation of the AI in many patients. A higher augmentation pressure and index measured by using the central artery pressure are associated with an increased risk of coronary artery disease (CAD).…”

Comparisons of microvascular and macrovascular changes in aldosteronism-related hypertension and essential hypertension

“…Several variables may influence PWV, including aldosterone plasma level, weight, age, use of anti-hypertensive drugs or statins 45–50 . Our population study consisted of patients with PA and EH who were well matched for all these baseline parameters.…”

Do thiazide diuretics reduce central systolic blood pressure in hypertension?

“…The results of this work contradict studies that have shown that diuretics appear to have no beneficial effect on central hemodynamics. Several agents, including thiazide diuretics, were shown to have a neutral effect on the reduction of CSBP and a neutral effect on the amplification of the pressure waveform moving from the aorta to the radial artery . Consistent data are available for bendrofluazide and indapamide, which also have neutral effects on AIx75 and pulse wave velocity, respectively …”