ABC | Volume 114, Nº4, April 2020

Original Article Fernandes et al. Galectin-3 in pericardial constriction Arq Bras Cardiol. 2020; 114(4):683-689 serve as a biomarker or modulator of severity in patients with constrictive pericarditis. The aim of this study was to assess plasma Gal-3 levels in patients with CCP and correlate these levels with functional and histologic parameters. Methods Study population In this prospective study, 33 patients with surgically proven constrictive pericarditis were included. Twenty-nine patients underwent radical pericardiectomy from February 2011 through November 2015 in a tertiary hospital in São Paulo, Brazil. Four patients were excluded from the study by the following exclusion criteria: patients older than 70 years old, severe pulmonary disease according to a lung test, and moderate/severe valvular heart disease. Twenty-five patients were compared with 21 healthy, physically inactive individuals without heart disease (control group). The sample size was defined by convenience. The presumptive diagnosis of CCP was based on clinical, echocardiographic, and cardiac magnetic resonance (CMR) imaging criteria according to European Society of Cardiology guidelines and proven by surgery. 1 The following procedures were performed during hospitalization for surgery: measurement of serum B-type natriuretic peptide (BNP) levels, transthoracic echocardiography, cardiopulmonary exercise test (CPET) and CMR imaging test (Figure 1 depicts the screening process). Tuberculosis constriction was defined by pericardial biopsy, when caseating granuloma was demonstrated or polymerase chain reaction was positive for Mycobacterium sp . Postsurgical constriction was defined as constrictive pericarditis after cardiac surgery. Constriction secondary to systemic inflammatory disease was defined in two patients with lupus erythematosus. Idiopathic constriction was defined when patients did not qualify for any of the previous groups. Study design This was a case control study with controls (healthy subjects) paired by age and sex. Procedures Pericardiectomy procedure Median sternotomy was performed in all cases without cardiopulmonary bypass. Total pericardiectomy was performed with excision of the pericardium anteriorly, extending to both phrenic nerves and diaphragmatic pericardium. When this procedure was technically impossible, removal of parietal and visceral pericardium was attempted. Cardiopulmonary exercise test Functional capacity was evaluated using the CPET, according to American Heart Association guidelines. 6 The evaluation was performed on a treadmill ( Ergoline - Via Sprint 150 P ) with modified Balke protocol with velocity varying from2 to 3.4mph and a ramp increment of 2% per minute. After placement on the treadmill, patients were connected to a volume transducer, with nose clipped, electrocardiographic monitoring ( Micromed - Cardio PC 13 ) was performed. The oxygen (O 2 ) and carbon dioxide (CO 2 ) fractions were measured at each respiratory cycle. This evaluation was performed using a computerized system ( Sensormedics, Vmax Analyzer Assembly, Encore 29S ). Blood pressure was assessed by the auscultatory method, and measurements were taken every two minutes of exercise. In the recovery period, blood pressure was measured in the first, second, fourth, and sixth minutes. The cardiopulmonary exercise test was considered maximum when the individual reached at least one of the following parameters: respiratory exchange ratio > 1.10, heart rate > 95% of predicted for age, and extreme tiredness. BNP assays were performed using the ADVIA Centaur® Kit ( Siemens Medical Solutions Diagnostic, Los Angeles, California, USA ) and processed in automated equipment of the same brand. Samples were processed within two hours as recommended by the manufacturer. PlasmaGal-3 levels were determined using an Enzyme-Linked Fluorescent Assay ( ELFA ) and measured on Biomerieux Vidas 30 ( Biomerieux, Marcy l’Etoile, LY-France ). Calibration of the assaywas performed according to the manufacturer’s recommendations. Figure 1 – Screening process. Patients underwent pericardiectomy between February 2011 and November 2015 (n = 29) Patients enrolled (n = 25) 01 age > 70 years 01 severe pulmonary disease 01 severe valvular heart disease 01 death before inclusion 684