ABC | Volume 111, Nº1, July 2018

Special Article Executive Summary – Guidelines for Mechanical Circulatory Support of the Brazilian Society of Cardiology Silvia Moreira Ayub-Ferreira Instituto do Coração do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP - Brazil Hospital Sírio-Libanês, São Paulo, SP - Brazil Keywords Heart Failure/complications, Heart Failure/therapy; Myocardial Ischemia/complications; Assisted Circulation/ instrumentation; Contraindicators; Risk Assessment. Mailing Address: Silvia Moreira Ayub-Ferreira • Rua Enéas Carvalho de Aguiar, 44. CEP 05403-000, São Paulo, SP - Brasil E-mail: silvia.ayub@incor.usp.br DOI: 10.5935/abc.20180126 Evaluation of candidates for mechanical circulatory support devices In advanced heart failure (HF), the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) proposed seven clinical profiles (and modifiers) for a convenient, easy classification of disease status, risk of implantation of mechanical circulatory support devices (MCSDs) and adequate time for intervention (Chart 1). 1 One of the main determinant factors for a successful MCSD implantation is patient eligibility. Correct selection of patients involves – (1) patients with advanced HF to which the risk of MCSD implantation surpasses mortality risk for current disease (making it a beneficial intervention); (2) patients withmoderately advanced HF, i.e., implantation of MCSD would not increase patient’s morbidity andmortality due to increased complication rate; (3) no contraindications for MCSD implantation. 2,3 Perioperative renal failure, pre-existing right HF, liver dysfunction, mechanical ventilation in the pre-operative period, low weight or overweight and reoperation have been related to worse clinical outcomes after MCSD implantation. 3-5 The main scores for risk prediction in MCSD implantation are described in Chart 2. Echocardiography Evaluation of patients candidates for MCDS should include a transthoracic echocardiogram (TEE) complemented by a transesophageal echocardiography (TEE). The effects of MCDS on right ventricular function depend on the balance between the benefits of decompression of the left chambers (reduction of the left ventricular afterload) and greater volumetric load to the right atrium (RA; increase of the right ventricular preload). Decompression of left chambers also cause changes in the geometry of the right chambers, such as leftward shift of interatrial (IAS) and interventricular septum (IVS), structural changes of tricuspid annulus, which can aggravate a pre-existing tricuspid insufficiency (TI) and right ventricular overload. 10 Considering that right ventricular cardiac output determines left ventricular preload, a significant reduction in right ventricular function results in decreased output by the MCSD. It is estimated that approximately 30% of patients with left ventricular assist device develop limiting right ventricular dysfunction. For these reasons, a careful evaluation of right ventricular function is mandatory before MCDS implantation. In the presence of moderate-to-severe dysfunction, the requirement of a permanent biventricular support cannot be ruled out. 11 In the assessment of right ventricular function before MCSD implantation, it is recommended the measurement of the right ventricle, as well as a semiquantitative assessment of right ventricular longitudinal and radial contractility combined with quantitative parameters, including fractional area change (FAC; FAC < 20% are associated with increased risk of right ventricular dysfunction after MCSD implantation), 12 tricuspid annular plane systolic excursion (TAPSE) determined by M mode, peak systolic velocity of lateral tricuspid ring, measured by tissue Doppler (s’), and right ventricular performance index. 13,14 Predictors of right ventricular dysfunction before mechanical circulatory support device implantation Right ventricular dysfunction is multifactorial and includes an increase in preload, ventricular ischemia and mechanical interdependence of ventricular geometry. It is one of the most severe complications of left ventricular assist device, observed in up to 30% of cases and associated with a six-fold increase in morbidity and mortality (increased risk in up to 67%). 11,15 Risk factors and the main risk score for right ventricular dysfunction after MCSD implantation are described in Charts 3 and 4. Implantation of a MCSD in the left ventricle should be performed with caution in patients with important right ventricular dilation, moderate-to-severe tricuspid insufficiency, tricuspid valve annulus > 45 mm and CVP > 15 mmHg. By this means, hemodynamic variables directly reflect a preload or afterload increase and right ventricular contractility reductions, whereas venous congestion and organ hypoperfusion, consequence of right ventricular dysfunction, indicate hepatic and renal dysfunctions 15,21 Positive hemodynamic indicators of adequate right ventricular function that might reduce the risk of post‑MCSD implantation dysfunction are: CVP ≤ 8 mmHg; PCP ≤ 18 mmHg; CVP/PCP ≤ 0,66; pulmonary vascular resistance (PVR) < 2 wood units and right ventricular work index ≥ 400 mL/m 2 . 4