Author(s): Vivencio Barrios [**] 1 , Antonio Coca 2 , Carlos Escobar 3 , Rosa Enrique 4 , Luis Miguel Rincón 5
angiotensin-converting enzyme inhibitors; angiotensin receptor blockers; clinical practice; renin-angiotensin system; treatment
The renin-angiotensin-aldosterone system (RAAS) is critical for human physiology  . Under normal conditions, the RAAS is implicated in cardiovascular homeostasis, blood pressure (BP) regulation, sodium and water balance, and for cellular growth and replication  . However, although RAAS is necessary, its excessive activation is deleterious, and it has been associated with the establishment and progression of vascular disease (hypertension, left ventricular hypertrophy, ischemic heart disease, heart failure, renal disease, microalbuminuria, stroke or retinopathy, among others) [3-5] .
Angiotensin-converting enzyme inhibitors (ACEis) and angiotensin receptor blockers (ARBs) are the most frequently used RAAS blockers. Although both are RAAS inhibitors, there are some important differences, which may have a significant impact on clinical events. ACEis do not act on Ang II generation via nonangiotensin-converting enzyme pathways, whereas ARBs block the effects mediated by the AT1 receptor of Ang II. As Ang II can be produced through angiotensin-converting enzyme-independent pathways, it is suggestive that ACEi may provide a suboptimal long-term RAAS blockade. Moreover, ARBs only block AT1 receptors and may activate AT2 receptors, while ACEis affect both AT1 and AT2 receptors similarly. This may be important as the activation of AT1 receptors exert vasoconstriction and proliferative effects, whereas AT2 receptor stimulation promotes vasodilator and antiproliferative effects  . Despite all these different properties, which could potentially favor ARBs, the ONTARGET trial showed that an ARB was equivalent to an ACEi in high-risk patients such as those with vascular disease or diabetics with target organ damage  .
Although RAAS has a key role along the entire cardiovascular continuum, and many randomized clinical trials have shown the benefits of both ACEis and ARBs in cardiovascular disease [1,6-13] , to date the available information regarding how these drugs, alone or in combination, are used in general practice is very scarce.
The RAS study was a multicenter and cross-sectional survey, carried out to determine the cardiovascular risk profile and the clinical characteristics of patients treated with RAAS inhibitors in conditions of daily clinical practice and whether they are used according to current clinical recommendations.
Physicians from primary care, hypertension units and different medical specialties related to the cardiovascular disease, such as cardiology, internal medicine, nephrology or endocrinology, participated in this study. The primary end point was to assess the clinical profile and cardiovascular risk of the patients treated with RAAS inhibitors. The secondary objectives were to determine the reasons for the prescriptions of RAAS inhibitors and for choosing an ARB or an ACEi in each condition.
A total of 386 investigators from many area of Spain participated in the study performed during the fourth quarter of 2009. Each investigator was asked to consecutively include subjects the attended at the outpatient clinic who met the inclusion criteria. Patients of both genders, aged [greater than or equal]18 years, undergoing treatment with RAAS inhibitors (ACEis, ARBs or both) for at least 6...