ABC | Volume 114, Nº4, April 2020

Original Article Schmidt et al. Physical fitness and quality of life in HFpEF Arq Bras Cardiol. 2020; 114(4):701-707 balance and mobility, muscular fitness, cardiorespiratory fitness (CRF) and body composition) 8 and, in parallel, QoL is a multidimensional construct (e.g. general, emotional and physical). 9 Until now, it remains unknown how the different components of physical fitness correlate with the specific dimensions of QoL in HFpEF patients. To date, it has only been demonstrated that a higher CRF is associated with a better QoL, mainly regarding the physical dimension. 7,10 However, the influence of other physical fitness components on QoL dimensions is relatively unknown. Therefore, the clarification of this issue might have important clinical implications in the design of specific interventional programs for HFpEF patients targeting the physical fitness component, which most impacts on QoL, whether overall or one of its depressed dimensions. Therefore, the aims of the present study are twofold: i) to evaluate the association between different physical fitness components (CRP, upper body strength, dynamic balance and mobility, and body composition) and the QoL dimensions (total, physical and emotional) in HFpEF patients, and ii) to assess which of the physical fitness components are independently associated to different dimensions of QoL in this specific population. Methods Study design This is a cross-sectional study conducted in a Portuguese public hospital ( Centro Hospitalar do Porto - Hospital de Santo Antonio , Porto) with a convenience sample of HFpEF. Inclusion criteria was diagnosis of HFpEF according to the European Society of Cardiology guidelines. 11 Patients were excluded if they presented with unstable angina, acute coronary syndrome as primary diagnosis, symptomatic severe aortic stenosis, acute pulmonary embolism, acute myocarditis, decompensated heart failure, uncontrolled hypertension, complex ventricular arrhythmias, severe renal dysfunction, severe chronic obstructive pulmonary disease, medical or orthopedic conditions that precluded independent ambulation and exercise testing. Patients who were potentially eligible to participate in the study were identified from the clinical files of the hospital cardiology department. A total of 30 patients were invited through phone calls by a cardiologist. Of those, 24 patients (17 women and 7men) accepted to take part in the study. The study was approved by the Ethics Committee of Centro Hospitalar do Porto - Hospital de Santo Antonio ( N/S: 2015.125) and met the ethical standards of the Declaration of Helsinki. Data were collected from November 2016 to September 2017 during a single day in the hospital. Data collection Blood pressure A trained researcher performedbloodpressuremeasurements after a 10minute-rest in the sitting position. Blood pressure was assessed (Colin, BP 8800; Critikron, Inc., USA) in both arms, and the arm showing the highest BP was used. SBP and DBP were computed as the average of 3 readings, with a 2-minute interval between them. Additional readings were performed when differences between readings exceeded 5mmHg. 12 Blood collection and biochemical determinations Peripheral venous blood (15 mL) was collected into an EDTA tube. The EDTA tubes were immediately placed on ice and allowed to clot for 30 minutes before centrifugation for 15 minutes at 1000xg. The plasma was aliquoted and stored at -80ºC for biochemical analysis. Brain Natriuretic Peptide (BNP) was quantified in a certified laboratory using chemiluminescent microparticle immunoassay (ARCHITECT BNP). Anthropometric and body composition measures Body height (cm) was measured in the upright position using a stadiometer (Holtain Ltd., Crymmych, UK). 13 Weight (kg), body mass index (BMI; kg·m 2 ), fat mass (%) and free fat mass (kg) were measured with patients wearing light clothes, using an electronic segmental body composition analyzer (Tanita, BC-418, Tokyo, Japan). Fat mass and free fat mass were measured using bioelectrical impedance. Patients were asked to fast for 10-12 hours, avoid vigorous physical exercise and alcohol intake before being measured. Waist circumference (cm) was measured at the midpoint between the lowest rib and the iliac crest at the end of normal expiration. 14 Obesity was determined as BMI equal or higher than 30 kg/m 2 . 15 Functional classification Patients were classified by the physician into subgroups based on their symptoms using the New York Heart Association (NYHA) functional class. Patients’ symptoms are based on how much they were limited during physical activity (class I to IV). 16 Echocardiography Evaluation Supine transthoracic echocardiography was performed using a cardiovascular ultrasound model Vivid E95 ® (GE Healthcare). All quantitative echocardiographic measurements were performed by a single reader blinded to the results of the other evaluations, using a computerized off-line analysis station. Peak early diastolic tissue velocity was measured at the septal and lateral mitral annulus. Mitral inflow velocity was assessed by pulsed wave Doppler at the apical 4-chamber view, positioning the sample volume at the tip of the mitral leaflets. E/e’ ratio was calculated as E wave divided by e’ velocities. LV mass was estimated based on LV linear dimensions and indexed to body surface area, as recommended by ESC guidelines.17 LV hypertrophy was defined as LV mass indexed to body surface area (LV mass index) >115 g·m 2 in men or >95 g·m 2 in women. LV volumes were estimated by the modified Simpson method using the apical 4- and 2-chamber views, and LVEF was derived from volumes in the standard manner. LA volume was estimated by the method of disks using apical 4- and 2-chamber views at an end-systolic frame preceding mitral valve opening and was indexed to body surface area to derive LA volume index. 702