ABC | Volume 111, Nº5, November 2018

Original Article Lima et al High-intensity interval training and heart failure Arq Bras Cardiol. 2018; 111(5):699-707 Table 1 – Participants’ characteristics at baseline Characteristic n = 16 Female 9 (56%) Age (years) 59 ± 7 Weight (kg) 87 ± 28 Height (cm) 159 ± 10 Body mass index (kg/m 2 ) 34 ± 7 Waist circumference (cm) 110 ± 27 Smoking Active smoker 2 (12%) Former smoker 7 (44%) NYHA functional classification II 12 (75%) III 4 (25%) Comorbidities Hypertension 16 (100%) Diabetes 7(44%) Rheumatic disease (gout) 2 (12%) Atrial fibrillation 1 (6%) CRF 4 (25%) AMI 2 (12%) Stroke 3 (19%) Medications ACEI/ARA 16 (100%) Beta-blockers 13 (81%) Diuretics 13 (81%) Calcium channel blockers 11 (69%) Statins 10 (62%) Antiplatelets 9 (56%) Vasodilators 7 (44%) Hypoglycemic drugs 7 (44%) Values are described as mean ± standard deviation or absolute frequency (percentage). Former smoker: more than 1 year without smoking; NYHA: New York Heart Association; CRF: chronic renal failure; AMI: acute myocardial infarction; ACEI: angiotensin-converting enzyme inhibitors; ARA: angiotensin receptor antagonists. Table 2 – Echocardiographic variables Variables n = 16 LVEF (%) 68 ± 5 E/e’ 13 ± 4 LAD (cm) 4.22 ± 0.41 LVESV (ml) 37.9 ± 9.10 LVEDV (ml) 124.41 ± 23.24 LVEDVI (ml/m 2 ) 67.09 ± 6.35 IVST (cm) 1.15 ± 0.17 PWT (cm) 1.10 ± 0.19 LVM (g) 244.35 ± 58 LVMI (g/m 2 ) 146.2 ± 35.84 LAVI (ml/m 2 ) 20.81 ± 3.40 Values are described as mean ± standard deviation.LVEF: left ventricular ejection fraction; E/e’: early diastolic peak velocity and diastolic peak velocities of the mitral annulus ratio; LAD: left atrium diameter; LVESV: left ventricular end-systolic volume; LVEDV: left ventricular end-diastolic volume; LVEDVI: left ventricular end-diastolic volume indexed to body surface; IVST: interventricular septum thickness; PWT: posterior wall thickness; LVM: left ventricular mass; LVMI: left ventricular mass indexed by body surface; LAVI: left atrial volume indexed to body surface. Table 3 – Cardiopulmonary exercise testing variables Variables n = 16 VO 2 peak (mL.kg -1 min -1 ) 18.40 ± 3.16 HR max. (bpm) 125 ± 23 VE/VCO 2 slope 33 ± 6 PET CO 2 rest (mmHg) 33 ± 3 Pulse O 2 11.36 ± 4.45 R peak 1.16 ± 0.13 Values are described as mean ± standard deviation or median±interquartile range. VO 2 peak: peak oxygen consumption; HR max.: maximum heart rate; VE/VCO 2 slope: incline of the ventilatory equivalent of carbon dioxide; PET CO 2 rest: expired pressure of carbon dioxide; O 2 pulse: oxygen pulse; R peak: respiratory quotient. Finally, in a condition characterized by exercise limitation, aerobic exercise training has a significant role and is indicated for all patients capable of performing it. In an acute and subacute setting, HIIT reduced BP and increased brachial artery diameter, suggesting that this training modality could be a beneficial alternative for individuals with HFpEF. Limitations and future perspectives This was a small, single-center; before-and-after study with HEpEF patients where the presence of diabetes, atherosclerosis, gout, and use of tobacco may have influenced the study outcomes. However, these characteristics represent the reality of this complex syndrome which have multiple comorbidities. We acknowledge that further studies are necessary to evaluate the effect of a HIIT session, especially after one hour, as well as the long-term efficacy of this exercise strategy as part of a cardiovascular rehabilitation program for these patients. Finally, the presence of a control group of matched individuals without HFpEF could help establishing which responses can be attributed to the syndrome under study. Likewise, comparing a HIIT session with a continuous moderate-intensity training session could help establishing the differences in hemodynamic response among these different exercise protocols. 703