Evaluation of the Right Ventricle in Candidates for Right Ventricular Assist Device Implantation. Evaluation of RVAD Function. Ioannis A Paraskevaidis Attikon University Hospital
Historical Perspective on Mechanical Support Stewart GC et al,. Circulation 2012 ;125:1204-15 Rose EA et al,. NEJM 2001 ;345:1435-43
The Competing Outcomes for MC Support Miller LW et al,. NEJM 2007;357:885-96 INTERMACS Registry, Holman WL. Circulation 2012 ;126:1401-06
Indications for Mechanical Support LVAD RVAD LVAD BiVAD Long or Short term support <or>7 days) Pre - existing or newly developed dysfunction BiVAD Cardiogenic shock after AMI Post-surgical BiVAD LVAD RVAD LVAD Most common indication Persistent hemodynami c instability BiVAD Decompensated chronic HF Acute cardiac failure from myocarditis Delgado, DH et al,. Circulation 2002 ;106:2046-50
Decision Tree for VAD Stewart GC et al,. Circulation 2012 ;125:1204-15
Is RV Important? In CHF After LVAD implantation RVEF>35% RVEF=25-35% RVEF<25% De Groote P et al,. JACC 1998;32:948 Genovese AE. et al,. Ann Thorac Surg. 2009 ;88:1162-70 Meyer Ph. et al,. Circulation 2010 ;121:252-58 Drakos SG. et al,. Am J Cardiol. 2010 ;105:1030-35
Comparison of LV & RV Response to LVAD RV myocardial efficacy is maintained by a decrease in RV afterload and an increase in RV preload. RV contractility is depressed due to inherent properties and to leftward septal shift Patients supported with an LVAD alone demonstrate less RV structural remodeling, There is a tendency of the RV to develop a more circular shape in some patients that may result in worsening RV function. Barbone A et al,. Circulation 2001;104:670-5 Ranjit J. et al,. J Cardiov Trans Res 2010 ;3:604-11
RV Function During LVAD Support Factors contributing to RV failure Pre-operative RV dysfunction Chronically elevated afterload as a results of Pulmonary Hypertension or secondary to myopathy of the right ventricle itself Ischemia Peri-operative fluctuation in pulmonary vascular resistance Complement activation and blood transfusions increase pulmonary vascular resistance and result in increased right ventricular afterload Excessive right ventricular pre-load Excessive LVAD flows may result in excessive right ventricular preload Altered inter-ventricular imbalance The unloading of the left ventricle may cause the inter-ventricular septum to shift leftward Maeder MT et al,. J Heart & Lung Transplantation 2009 ;28:360-6 Craig ML. Curr Heart Fail Rep 2011; 8:65 71
A Pre-operative Assessment of RV Failure in LVAD Candidates Matthews JC et al,. JACC 2008;51:2163-72
Prediction of RV Dysfunction Following LVAD Support Michigan RV Risk Score Use of pre-operative vasopressor agents (4points) Creatinine>2.3mg/dl (3 points) Bilirubin>2mg/dl (2.5 points) Asparate Aminotransferase >80IU/dl (2 points) Grant ADM et al,. JACC 2012 ;60:521-8
LV 2D Echo Study Predict RV Failure Following LVAD Implantation Kato TS et al,. Am J Cardiol 2012;109:246 51
Are RV Risk Scores Useful? The use of risk scores failed to predict the need of RV support after LVAD. Stratification of the hazard with these scores should occur with extreme caution. Pettinaria M et al,. Eur. J of Cardio-thoracic Surg 2012 :1-6
Echo Assessment of Mechanical Support Pre-VAD insertion Evaluating suitability of patient for VAD placement Assessing significant cardiac abnormalities that could lead to postoperative complications. 1. left heart chamber function and structure, 2. the quantification of RV function and TR, 3. the assessment for aortic and mitral regurgitation 4. examine a patent foramen ovale, or the presence of intracardiac clots Postoperative Value of Echocardiography Evaluate the surgical results of the VAD implantation To determine reasons for postoperative hemodynamic compromises 1. overall structure and function of left heart chambers 2. quantification of RV function and TR 3. proper inflow and outflow cannula placement
RV Assessment by Echo RVSP= TR Velocity + RAP (determined by IVC) (VTI & Acceleration Time) PVR= TVR (m/s) / TVI-RVOT (cm) X 10 + 0.16 (Woods units) RVFAC: (RVAd-RVAs)/RVAd (32-60%) TAPSE >15 mm Kaitlyn MTL et al,. JASE 2009 ;22:1055-62
RV Assessment by Echo RV Function -RV Size, Volumes, Pressures, -Factional Area, -TAPSE, TDI: Peak systolic wave velocity, acceleration time, -Tricuspid annular dilation, -Severe leftward shifting of IVS. Elevated RA pressure -Interatrial septal motion (leftward Shifting), - Tricuspid diastolic inflow pattern, - Size of inferior vena cava, Hepatic Vein Flow Pattern. VAD Validation -Small LV and/or collapsed around the inflow cannula, -Systemic CO assessment. -Pump Speed
Assessment by 3D Echo RV Structure & Function, MV-TV
Corrected Time interval between the onset and cessation of TR flow Early Systolic Equalization of RV and RA pressure Topilski Y et al,. JACC Img 2011;4:211-22
Tissue Doppler in RV Sa Ea Aa Meluzin J et al,. Eur J Echocardiography 2003 ;4:262-71
Prediction of RV Dysfunction After LVAD Speckle Tracking Grant ADM et al,. JACC 2012 ;60:521-8
Echo Variables at Various Continuous-Flow Pump Speed Settings
Echo & hemodynamic data under different Continuous- Flow Pump Speed Low Speed High Speed LV diameter decrease Inter- ventricular atrial septa shifted to the right Lower MR Severity Normalization of Wedge, RV & RA pressure
Conclusions The incidence of RVF after LVAD implantation is significant, and the presence of RVF is associated with higher rates of mortality and longer lengths of hospitalization. Unfortunately, consistent identification of preoperative predictors of RVF has proven more difficult. Echo along with Clinical, Laboratory, and Hemodynamic findings can determine RV dysfunction both at preand post device implantation time.