ABC | Volume 113, Nº6, December 2019

Original Article Leite et al. Risk of sleep apnea and echocardiographic parameters Arq Bras Cardiol. 2019; 113(6):1084-1089 In patients with controlled arterial hypertension, Lisi et al. 21 observed that mild to moderate OSA, diagnosed by polysomnography, is associated with diastolic disfunction, regardless of age, gender and mean arterial blood pressure levels and in the absence of concentric left ventricular hypertrophy or increased left atrium. The authors suggest that nocturnal hypoxemia could be the key factor for the development of diastolic disfunction. 21 Hypertension is the main cause of diastolic disfunction and is also one of the biggest consequences of OSA. 22 Two studies excluded obese individuals from the analysis 20,23 and at least one excluded obese and hypertensive individuals. 23 The two articles studied solely individuals with OSA and compared the moderate OSA group with the one with severe OSA. In both studies, the E/A association was statistically significant. In the study of Imai et al., 23 LAV-i and E/E’ ratio were significantly bigger in the severe OSA group. The data from these two studies show that the association of the OSA with abnormal diastolic function may occur in non-obese and non-hypertensive individuals. Due to the high prevalence of these two conditions, in the present study, it was not possible to exclude them from the analysis to confirm the independent association and the risk of OSA and the indicators of diastolic disfunction. The present study evaluated the contribution of several echocardiographic parameters, which represent, with bigger reliability, the structural or cardiac function abnormalities that may be associated with the diagnosis of OSA. LAV-i. TD, E/A ratio, E’/A’ ratio and A wave abnormalities in individuals with OSA indicated a less effective diastolic function in patients with sleep disorders, compatible to findings that defined OSA through polysomnography. Limitations The BQ does not confirm the OSA and only points out those patients at risk for the syndrome, with reduced sensitivity and specificity, questionable reproductivity, because the perception and documentation of what is informed may not be precisely estimated, since it involves limitations resulting from the level of literacy or pre-existing cerebral vascular conditions of the informant, making it difficult to understand the BQ, especially by the elderly. Due to the limitation of resources and because it is a tracking study, each patient was examined by only one echocardiographer, preventing inter or intra-observer concordance examination. Despite these limitations, the results according to the TDE parameters among the risk groups were in line with those of the literature. Because it is a cross-sectional study, it was not possible to establish a causal link. Despite having excluded from the analysis hypertensive and obese individuals that who did not meet any other criterion for the risk of OSA according to the BQ, those at risk presented higher mean BMI, systolic and diastolic arterial pressure, which notwithstanding the control (inclusion in multiple models) still may have caused residual confounding. Conclusions Evaluation of the association of OSA and the presence of structural and functional cardiac abnormalities obtained by the TDE can contribute to a discussion about the adoption of the BQ in the community, to select individuals with cardiovascular risk that should undergo TDE, despite its limitations. This strategy of fast execution may be easily incorporated into the routine of assessment of patients with risk factors for the development of HF, but it still needs a detailed analysis and long-term follow-up for its definitive prescription. Author contributions Conception and design of the research: Leite AR, Garcia-Rosa ML, Lagoeiro AJ; Acquisition of data: Leite AR, Macedo EA, Vasques Netto D, Santos CC, Martinez DM; Analysis and interpretation of the data: Garcia-Rosa ML, Lagoeiro AJ; Statistical analysis: Garcia-Rosa ML; Writing of the manuscript: Leite AR, Garcia-Rosa ML, Macedo EA, Lagoeiro AJ, Martins WA, Vasques Netto D, Santos CC, Martinez DM; Critical revision of the manuscript for intellectual content: Garcia-Rosa ML, Lagoeiro AJ, Martins WA. 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 Adson Renato Leite, from Universidade Federal Fluminense. Ethics approval and consent to participate This study was approved by the Ethics Committee of the Hospital Universitário Antônio Pedro under the protocol number 0077.0258.000-10. All the procedures in this study were in accordance with the 1975 Helsinki Declaration, updated in 2013. Informed consent was obtained from all participants included in the study. 1088