Arquivos Brasileiros de Cardiologia (May 2008)
Índice Tornozelo-Braquial (ITB) determinado por esfigmomanômetros oscilométricos automáticos Assessing Ankle-Brachial Index (ABI) by using automated oscillometric devices
Abstract
FUNDAMENTO: Índice Tornozelo-Braquial (ITB) é essencial na prática clínica, mas dificuldades técnicas na sua execução pelo padrão de referência Doppler vascular (DV) tornam-no ainda pouco utilizado. OBJETIVO: Avaliar aplicabilidade da determinação do ITB com uso de esfigmomanômetros oscilométricos automáticos (EOA) e sugerir a utilização dos índices delta-Bráquio-Braquial (delta-BB) e delta-ITB como marcadores de risco cardiovascular. MÉTODOS: Estudo descritivo e observacional de 247 pacientes ambulatoriais (56,2% feminino, média 62,0 anos) submetidos à determinação do ITB com aferição simultânea da pressão arterial (PA) em membros superiores (MMSS) e inferiores (MMII) utilizando-se dois EOA (OMRON-HEM705CP). Nos casos em que não foi possível aferir PA em pelo menos um dos MMII utilizou-se DV. Os pacientes divididos em Grupo N (ITB normal: 0,91 a 1,30) e Grupo A (ITB alterado: 1,30) tiveram comparados entre si os valores de delta-ITB (diferença absoluta ITB/MMII) e delta-BB (diferença absoluta PAS/MMSS). RESULTADOS: Utilizando-se EOA foi possível determinar ITB em 90,7%. Com dados do Grupo N determinaram-se valores de referência (VR) no percentil 95 de delta-ITB (0-0,13) e delta-BB (0-8 mmHg). Quando comparado com o Grupo N, o Grupo A apresentou prevalência mais elevada tanto de delta-ITB (30/52 contra 10/195; Razão de Chances: 25,23; pBACKGROUND: Assessing Ankle-Brachial Index is an essential procedure in clinical settings, but since its measurement by the gold standard Doppler Ultrasonic (DU) technique is impaired by technical difficulties, it is underperformed. OBJECTIVE: The aim of this study was to assess the efficacy of an automated oscillometric device (AOD) by performing Ankle-Brachial Index (ABI) assessments and to suggest delta brachial-brachial (delta-BB) and delta-ABI as markers of cardiovascular risk. METHODS: In this observational and descriptive study, 247 patients (56.2% females, mean age 62.0 years) had their arterial blood pressure (ABP) measured for ABI calculation. Two AOD (OMRON-HEM705CP) devices were used for simultaneous measurements of the ABP, first of the two arms and then of the arm with higher systolic ABP and a leg, first the left and then the right one. When leg ABP measurements were not possible, ABI determination was performed by using the standard Doppler Ultrasonic (DU) technique. Patients were designated to Group N (normal ABI: 0.91 to 1.30) or Group A (abnormal ABI: 1.30). Other indexes were also calculated: delta-BB (absolute difference in mmHg of systolic ABP between arms) and delta-ABI (absolute difference of ABI between legs) and the results were compared. RESULTS: In most patients (90.7%), it was possible to determine the ABI. Group N data allowed calculation of the 95th percentile reference values (RV) of delta-BB (0 to 8 mmHg) and delta-ABI (0 to 0.13). When compared to Group N, Group A had a significantly higher prevalence of high values greater than the RVs of delta-ABI (30 of 52 and 10 of 195, respectively; Odds Ratio = 25.23; p<0.0001) and delta-BB (13 of 52 and 7 of 195, respectively; Odds Ratio = 8.95; p<0.0001). CONCLUSION: In most patients, the ABI could be measured by AOD. Both indexes, delta-BB and delta-ABI greater than the RVs, were significantly more prevalent in patients with abnormal ABI values, and their usefulness as new markers of cardiovascular disease should be further appraised in epidemiological studies.
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