ABC | Volume 111, Nº5, November 2018

Original Article Vasodilation and Reduction of Systolic Blood Pressure after One Session of High-Intensity Interval Training in Patients With Heart Failure with Preserved Ejection Fraction Juliana Beust de Lima, Anderson Donelli da Silveira, Marco Aurélio Lumertz Saffi, Márcio Garcia Menezes, Diogo Silva Piardi, Leila Denise Cardoso Ramos Ramm, Maurice Zanini, Rosane Maria Nery, Ricardo Stein Hospital de Clínicas de Porto Alegre - Universidade Federal do Rio Grande do Sul, Porto Alegre, RS – Brazil Mailing Address: Juliana Beust de Lima • R. Ramiro Barcelos, 2350, Postal Code 90035-007, Santa Cecilia, Porto Alegre, RS - Brazil E-mail: julianabeustdelima@gmail.com Manuscript received February 27, 2018, revised manuscript May 23, 2018, accepted May 23, 2018 DOI: 10.5935/abc.20180202 Abstract Background: Heart failure with preserved ejection fraction (HFpEF) is a multifactorial syndrome characterized by a limited exercising capacity. High-intensity interval training (HIIT) is an emerging strategy for exercise rehabilitation in different settings. In patients with HFpEF, HIIT subacute effects on endothelial function and blood pressure are still unknown. Objective: To evaluate the subacute effect of one HIIT session on endothelial function and blood pressure in patients with HFpEF. Methods: Sixteen patients with HFpEF underwent a 36-minute session of HIIT on a treadmill, alternating four minutes of high-intensity intervals with three minutes of active recovery. Brachial artery diameter, flow-mediated dilation, and blood pressure were assessed immediately before and 30 minutes after the HIIT session. In all analyses, p <0.05 was considered statistically significant. Results: There was an increase in brachial artery diameter (pre-exercise: 3.96 ± 0.57 mm; post-exercise: 4.33 ± 0.69 mm; p<0.01) and a decrease in systolic blood pressure (pre-exercise: 138±21mmHg; post-exercise: 125±20mmHg; p<0.01). Flow-mediated dilation (pre‑exercise: 5.91 ± 5.20%; post-exercise: 3.55 ± 6.59%; p = 0.162) and diastolic blood pressure (pre-exercise: 81 ± 11 mmHg; post‑exercise: 77 ± 8 mmHg; p = 1.000) did not change significantly. There were no adverse events throughout the experiment. Conclusions: One single HIIT session promoted an increase in brachial artery diameter and reduction in systolic blood pressure, but it did not change flow-mediated dilation and diastolic blood pressure. (Arq Bras Cardiol. 2018; 111(5):699-707) Keywords: Heart Failure; Arterial Pressure; Exercise; Vasodilatation; Brachial Artery; Endothelium/function. Introduction Heart failure with preserved ejection fraction (HFpEF) is a complex and prevalent clinical syndrome characterized by a significant limitation to exercising capacity, and pharmacological treatment has not evidenced any improvement in mortality rates in this scenario yet. 1,2 Therapeutic approaches are limited and they are mainly based on symptom management and control of cardiovascular risk factors, such as high blood pressure (BP). 3-5 Hypertension is associated with increased oxidative stress and vascular inflammation, closely related to endothelial dysfunction. 6,7 On the other hand, attenuated endothelial function in individuals with HFpEF contributes to intolerance to exercising 8-10 and it is an independent predictor of adverse cardiovascular events. 11,12 As a non-pharmacological intervention, exercise training appears as a potential strategy to be included in HFpEF’s therapeutic arsenal. 13,14 High-intensity interval training (HIIT) has emerged as an exercise modality with a positive impact on some cardiovascular outcomes, and it is at least as effective as moderate-intensity continuous training in patients with heart failure with reduced ejection fraction. 15-17 Recent meta‑analyses have demonstrated that HIIT, in a long-term basis, is more effective in promoting endothelial function improvement and BP reduction in individuals with cardiovascular risk factors. 18,19 In previous studies, after one singleHIIT session, patients with coronary artery disease and hypertension showed increased brachial artery diameter, 20,21 improved endothelial function, 20 and reduced BP. 21-23 It is well known that HFpEF patients have attenuated vasodilator reserve while exercising and their ventricular‑arterial coupling responses are impaired. 9,10,24 However, the effect of one HIIT session on endothelial function and BP in these patients is still unknown. Considering this gap in the literature, the aim of this study was to evaluate brachial artery diameter, endothelial function, and BP 30 minutes after one HIIT session in patients with HFpEF. 699