Abstract Introduction The goal of antihypertensive therapy is to prevent complications. The harmful effects of aldosterone are innumerable: induced cardiac/renal fibrosis, sodium and water retention, inflammation, oxidative stress, among others, that are involved in arterial/myocardium stiffness, remodelling, heart failure and new-onset atrial fibrillation (AF). Thiazide diuretics can activate the neurohormonal system, impair glucose metabolism, increase new-onset diabetes, and are potentially arrhythmogenic. Protective effect of Angiotensin Receptor Blockers (ARB) on major cardiovascular events might be partly independent of the degree of blood pressure reduction. Mineralocorticoid Receptor Antagonists (MRA) therapy reduce arterial stiffness, plasma volume, collagen/elastin ratio and vascular/myocardial fibrosis. Purpose The objective was to assess the levels reached in central haemodynamic parameters (CHP) and the presence of episodes of AF during ARB+hydrochlorothiazide (Hct) versus ARB+MRA therapy in hypertensive patients with normal kidney function. Methods For this cross-sectional retrospective study, data were entered from 108 hypertensive patients, female 62 (ARBs+MRA/ARB+Hctz average age 67/71), male 46 (average age ARB+MRA/ARB+Hctz 67/71), both p=ns). The average doses of Hct among female/male were 16/19 mg and the duration of the ARB+Hctz therapy were 37/47 months, while the ARB+MRA therapy were 36/49 months. 24-hours Holter monitoring was used in all patients. The group ARB+MRA before therapy had a history of AF episodes. The CHP (Central Aortic Pressure, End-Systolic Pressure, Mean Arterial Pressure, Pulse Pressure, Augmentation Pressure, Augmentation Index) were registered by the SphygmoCor System PVX (AtCor-Medical, Australia), according system's standard methods. Also was measured the difference between the normal levels, and the observed values of Augmentation Index (Diff-AIx) according age. Results The results of CHP, Diff-AIx, systolic and diastolic blood pressure during association of ARB+MRA therapy compared to ARB+Hct, both genders, showed the lowest values with a highly statistically significant difference. The episodes of AF during 24-hours Holter monitoring in the group ARB+Hct therapy in female/male were 55%/71%; instead, in the ARB+MRA treated they were not found. Conclusions These findings suggest that the dual block with ARB+MRA therapy giving better CHP, reducing the stress to arterial-ventricular coupling, it could be helpful to prevent, the harmful effects of angiotensin-aldosterone system such as the development of heart failure and atrial fibrillation. Funding Acknowledgement Type of funding source: None