IJCS | Volume 33, Nº2, March / April 2020

149 16.4 mmHg (0.001). No statistical difference was found for the diastolic component of BP (Table 2). It is of note that, compared with peripheral pressures, central BP shows a better correlation with clinical outcomes. This is probably explained by the fact that central pressures have lower variability, and from the pathophysiological point of view, central pressure reflects the levels of tension on target organs. 22-26 In the comparison between central BP values obtained by tonometry and by oscillometry, no difference was found for cSBP, cDBP, PP amplification, andAIx, but differences were found for cPP (37.7 mmHg and 30.9 mmHg, p = 0.013) and PWV (8.4 m/s and 7.4 m/s, p = 0.013). These findings also corroborate previous findings showing a tendency of the oscillometric method in underestimating parameters of cBP. 12,14,15 A study with 320 patients comparing an oscillometric (ARCSolver - Mobil O Graph®) method with the tonometric (SphygmoCor®) method, the results of most parameters agreed with those obtained by tonometric method. 27 In another study with 89 patients, the authors also reported good reproducibility between the methodsand suggested that oscillometry should be considered in everyday clinical practice, as it is an easy- to-perform test, with good cost-benefit relationship. 28 A guideline on protocols, equipment and non-invasive methods for estimation of central BP, published by the Artery Society in 2017, showed that, comparedwith intra- arterial BPmeasurement and the non-invasive tonometry method, the oscillometric method tend to underestimate PWV measurements, which should be considered in the use of this method. 29 More recently, a risk score (SAGE score) has been validated, using clinical criteria to identify hypertensive patients at higher risk for developing elevated arterial spiffiness. In this patients, analysis of central BPwould be indicated, 30 i.e., there is a current thinking of the scientific community that the method should be incorporated in cardiovascular risk stratification as an effective tool to early detect patients at higher risk. Despite the small sample size, we believe that our main objective in this study, to compare central hemodynamics indices obtained by different methods in patients at low cardiovascular risk, was achieved. To our knowledge, this is the first nation-wide study to evaluate the reproducibility of the oscillometric method in comparison with tonometric method in patients with borderline BP or patients with stage 1 hypertension, that may contribute to the advance, debate and implementation of this tool into clinical practice. Conclusion The parameters of central BP and those that reflect arterial compliance, particularly PWV, show better correlationwith cardiovascular outcomes in hypertensive patients than peripheral BP measurements. The use of non-invasive methods (tonometry and oscillometry) were validated for intra-arterial BP measurements of these parameters. Although tonometry is considered the gold standard among non-invasive methods, oscillometry has good reproducibility and may be considered a promising instrument to be used in clinical practice. Author contributions Conception and design of the research: Barroso WKS, Vitorino PVO. Acquisition of data: Barroso WKS, Gonçalves CF, Berigo JAC, Melo MA, Oliveira ACA, Vitorino PVO. Analysis and interpretation of the data: Barroso WKS, Gonçalves CF, Berigo JAC, Vitorino PVO. Statistical analysis: Vitorino PVO. Writing of the manuscript: Barroso WKS, Gonçalves CF, Berigo JAC, Melo MA, Vitorino PVO. Critical revision of the manuscript for intellectual content: Barroso WKS, Gonçalves CF, Berigo JAC, Melo MA, Oliveira ACA, Lelis ES, SousaWM, Rezende JM, JardimTV, SousaALL, Jardim PCBV, Vitorino PVO. Potential Conflict of Interest No potential conflict of interest relevant to this article was reported. Sources of Funding There were no external funding sources for this study. Study Association This article is part of the thesis of master submitted by Milena Andrade Melo, from Universidade Federal de Goiás. Ethics approval and consent to participate This study was approved by the Ethics Committee of the Hospital das Clínicas da Universidade Federal de Barroso et al. Assessment methods for central blood pressure Int J Cardiovasc Sci. 2020; 33(2):145-150 Original Article