Monitoramento cardiovascular em tempo real durante a aplicação do teste de caminhada de seis minutos: avaliação clínico-funcional na síndrome metabólica

Abstract

Introduction: Cardiovascular diseases are the leading cause of death worldwide. In this context, the association of metabolic disturbances, such as obesity, hypertension, dyslipidemia and insulin resistance define the Metabolic Syndrome (MetS), increasing the cardiovascular risk in its carriers. With the progression of this disease, vascular injury and target organ damage implies the reduction in the functional capacity and quality of life. In this scenario, the development of low-cost tools presenting good reproducibility, providing prognostic information, becomes and important strategy for early cardiovascular screening. Before this, the present study aimed to monitor, using a real-time approach, the main cardiovascular parameters during the six-minute walk test (6MWT) in patients with MetS. Methods: For this case-control study, 24 MetS carriers were selected from the Federal University of Alagoas Teaching Hospital and 18 apparently healthy individuals from a private clinic, all age and socioeconomic status-matched. The diagnosis for the cases was established according to the Harmonized version of the MetS (2009). During the clinical assessment, systolic blood pressure, diastolic blood pressure, pulse pressure, mean arterial pressure and heart rate were obtained, followed by the anthropometric measurements. After a 12-hour fasting period, venous blood samples were collected for biochemical dosages. Non-invasive vascular assessment was performed using the ankle-brachial index (ABI), with a vascular doppler. Functional capacity was evaluated by using the 6MWT in two moments: the first, 6MWT I, was performed based on the conventional test, and later, the second test (6MWT II), with the real-time cardiovascular monitoring. Moreover, a questionnaire for assessing the quality of life was applied. Results: For the biochemical characterization, MetS carriers presented with major metabolic imbalance compared to the controls, with no differences between groups for the ABI. In the 6MWT I and 6MWT II, MetS patients showed lower walked distance than controls. However, no difference was observed for the physical functional capacity. Interestingly, patients with MetS presented a lower walked distance in the 6MWT II compared to the same group in the 6MWT I, with such difference not being observed for the controls. Furthermore, MetS carriers showed lower scores for the parameters related to the quality of life compared to the controls. For the correlation analysis, the major findings point to the inter-relationship between MetS diagnostic parameters and some variables assessed during the 6MWT, mainly for blood pressure data. Conclusion: The 6MWT was shown to be a useful tool for assessing the physical functional capacity in individuals with MetS. In addition, the adaptation of this test with real-time cardiovascular monitoring was presented as an important safety method for the evaluation of serious events while performing submaximal effort in individuals under cardiovascular risk.