ABC | Volume 113, Nº5, November 2019

Original Article Barroso et al. Telemedicine in hypertension diagnosis Arq Bras Cardiol. 2019; 113(5):970-975 the possibility of providing the necessary information for the appropriate diagnosis with greater comfort and better cost-benefit ratio. 7 Also, in relation to HBPM, the inclusion of the habitual BP measurements into the patient’s routine has shown an increase in compliance with drug treatment. This benefit seems to be even greater when using telemedicine platforms. 8,9 An adequate identification of MH andWCH is so important that the main guidelines of AH recommend the use of ABPM or HBPM in the diagnostic investigation whenever possible, emphasizing their use at the initial BP alterations. 1,2,3,7 The present study is the first national study to evaluate the prevalence of MH and white coat hypertension through the HBPM in prehypertensive and stage 1 hypertensive patients. Method ThisstudywassubmittedandapprovedbytheHumanResearch Ethics Committee of Hospital das Clínicas da Universidade Federal de Goiás under CAEE number 99691018.7.0000.5078. This is a retrospective study that evaluated the data of all patients who underwent exams on the TeleMRPA platform (www. telemrpa.com ) fromMay 2017 to September 2018. Of the total, those who underwent the examination for diagnostic purposes and were not using antihypertensive drugs were selected. Inclusion criteria were age older than 18 years; individuals assessed on the TeleMRPA platform, without the use of antihypertensive drugs and who had, by the casual measure (mean of two measurements) performed at the clinic on the first day of the protocol, SBP and DBP that met the criteria for the diagnosis of prehypertension (PH) - SBP ≥ 120 mmHg and/or DBP≥80mmHg and SBP<140mmHg andDBP<90mmHg; or stage 1 AH - SBP ≥ 140 mmHg and/or DBP ≥ 90 mmHg and SBP < 160 mmHg and DBP < 100 mmHg, according to the Brazilian Guideline of Arterial Hypertension (DBHA, Diretriz Brasileira de Hipertensão Arterial ). 1 The TeleMRPA platform was developed as a telemedicine monitoring tool, with characteristics that allow the analysis and filtering of the database according to the scientific questions to be investigated. There was a concern to develop and improve the mathematical algorithm aiming to allow the high quality of the analyzable data, either for the interpretation of the exam or for the development of research projects. In this context, the database protects the identification data of the patient and clinics or health units. Prior to the inclusion of data into the platform, the co-investigators were trained regarding the scientific evidence and methodology of the HBPM, as well as for the use of Omron automatic devices for BP measurements. The protocol used to obtain home measurements follows the recommendation of the Brazilian guidelines for HBPM, 7 which advises two measures to be carried out on the first day at the office or clinic (these measures are not used for the analysis of the mean home measurements) and six measurements a day on four consecutive days (three in the morning and three in the evening), with a total of 24 measures to calculate the mean. This mean value is considered normal when lower than 135/85 mmHg (Table 1). 1,2,7,8 It is recommended, on the first day, when the patient receives the device at the health unit, that the patient be taught the correct handling of the BP measuring device, as well as the technique for adequate and reliable measurement. This recommendation follows the DBHA guidelines. 1 Subsequently, the patient (or caregiver/companion) is instructed to measure the BP twice a day, following the abovementioned protocol. Patient data, as well as BP values, were included into the TeleMRPA platform and analyzed for the following variables: Socio-demographic data: gender, age, sample distribution and BP behavior by geographic regions; Anthropometric data: BMI using the Quetelet formula (BMI = weight in kg/height in meters 2 ). Blood pressure: mean BP at the clinic (first day), mean of home BP measures (second to fifth days) and mean BP in morning and evening, mean pulse pressure and BP variability. Database and statistical analysis The database was created using the Excel® (Microsoft) software with data imported from the TeleMRPA platform; the numerical codes were typed by three researchers with subsequent cross-checking to identify and correct typing errors. Continuous variables were presented as mean and standard deviation and categorical variables as absolute and relative frequencies. The Kolmogorov-Smirnov test was used to verify the distribution of the continuous variables. The paired t -test was used to compare BP measurements between the casual measurements and HBPM. To compare the frequencies of masked AH between stage 1 and stage 2 prehypertensive patients, the chi-square test was used, which was also used to compare the diagnoses of prehypertension and stage 1 hypertension between the casual BP measure and the HBPM. The significance level was set at p < 0.05. The Stata® software, version 14.0 was used for the analysis. Results The initial sample consisted of 4,350 individuals who underwent HBPM fromMay 2017 to September 2018 in nine Brazilian states. Of these, 1,273 participants with a clinical diagnosis of prehypertension or stage 1 AH and without use of medications (Figure 1) were selected, of which 853 (67.0%) were from the Northeast region, 43 (3.4%) from the North region, 10 (0.8%) from the Midwest region, 307 (24.1%) from the Southeast region and 60 (4.7%) from the South region. Mean age was 52.4 ± 14.9 years and the mean BMI was 28.4 ± 5.1 kg/m 2 . As for gender, 739 (58.1%) were women. The mean values of casual BP were 133.2 ± 11 mmHg and 84.1 ± 8 mmHg, and for HBPM, the mean values were 125.5 ± 11.7 mmHg and 78.9 ± 8 mmHg for SBP and DBP, respectively. The mean number of valid measures was 22.96. When comparing the means of the casual BP with the HBPM, higher values were found for casual BP in 7.6 mmHg for SBP and 5.2 mmHg for DBP, both with statistical significance (p < 0.001) (Figure 2). Considering the casual BP measurement, 703 (55.2%) participants were classified as prehypertensive and 570 (44.8%) as stage 1 hypertensive. When we considered the measures of the HBPM for the diagnosis, in the total sample, 558 (43.8%) were normotensive; 291 (22.9%) had sustained hypertension; 145 (11.4%) had MH; and 279 (21.9%) had WCH; that 971