Impact on Hypertension Reclassification by Ambulatory Blood Pressure Monitoring (ABPM) According to the V Brazilian Guidelines on ABPM

Background: New recommendations on reference values for normal test results in ambulatory blood pressure monitoring (ABPM) were proposed by the V Brazilian Guidelines on Ambulatory Blood Pressure Monitoring, based mainly on the IDACO study. Objectives: This epidemiological study is aimed at evaluating the impact of adopting these new standards in an arterial hypertension referral center. Methods: The results of 1,567 ABPM tests carried out between 2005 and 2010 were analyzed; 481 patients were excluded from the sample for not meeting minimum quality criteria of the test. Reference values from the IV Brazilian Guidelines on ABPM (2005) were used for the classification of these tests regarding the abnormality and compared with the changes proposed by the V Brazilian Guidelines on ABPM (2011). Statistical analysis was performed by Pearson's chi-square method and p values <0.05 were considered statistically significant. Results: For the 1,086 tests evaluated, there was a significant difference in the proportion of patients with altered ABPM results, especially for the variable systolic pressure in the sleeping period: 49% when adopting the cutoff values of 2005 and 71% when adopting the values of 2011, with statistical significance, p <0.0001. Conclusions: The recommendations of the new guidelines had a great impact on the hypertension classification by ABPM test results in the study population. The question of thresholds of these tests for therapeutic targets of patients known to be hypertensive is still open and requires further studies, preferably national ones, for better definition of the subject. (Arq Bras Cardiol. 2013; 100(2): 175-179)