DECLARATION OF CONFLICT OF INTEREST
Cardiovascular magnetic resonance for timing pulmonary valve replacement E.Valsangiacomo Buechel University Children s Hospital Zurich
Outline Introduction Pulmonary regurgitation Evidence for use of CMR Timing PVR Additional information by CMR /new insights Conclusions no conflicts of interest to disclosure
Repair of tetralogy of Fallot
Longterm follow-up 20-years survival rates 94% Nollert et al. JACC 1997
Longterm follow-up Major hemodynamic indications for reoperation ---------------------------------------------------------------------- Primary lesion n % RVOT complications 45 75 Severe pulmonary regurgitation 24 40 Conduit failure 13 22 RVOT obstruction 5 8 Severe PR and RVOT obstruction 3 5 VSD patch leak (Qp/Qs > 1.5) 6 10 Severe tricuspid regurgitation 3 5 Patent Blalock-Taussig shunt 3 5 Others 3 5 Oechslin et al. JTCS 1999
Pulmonary regurgitation Pulmonary regurgitation pulmonary valve function compliance of the RV pulmonary vascular resistance What should we measure? RV size and function PR volume RV and LV stroke volume Henkens et al. Ann Torac Surg 2007 Wald et al. Eur Heart J 2009 Knauth et al. Circulation 2005
Regurgitant fraction or regurgitant volume? Wald et al. Eur Heat J 2009
RV parameters by SSFP CMR Reproducibility Fallot: EDV <5% EF 5% ESV 10-15% Valsangiacomo Buechel et al. Eur Heart J 2005
Normal values for adults males females Maceira et al. Eur Heart J 2006
Normal values for children Valsangiacomo et al. JCMR 2009
Quantitative CMR assessment Pulmonary regurgitation RV enddiastolic volume (ml/m2) RV ejection fraction Reg fraction (%) Reg Volume (l/min/m2) borderline 100-110 40-50% mild <20 < 1 110-130 35-40% moderate 20-40 1 2.5 130-150 25-35% severe >40 > 2.5 >150 < 25%
Timing pulmonary valve replacement Definition of treshold values for pulmonary valve replacement : RVEDV/m2 Therrien, Am J Cardiol 2005 Valsangiacomo, Eur Heart J 2005 Geva, Pediatr Card Surg Ann 2006 170 150 160
Timing pulmonary valve replacement Preoperative treshold for RV volume normalization: RV endiastolic volume < 160 ml/m2 RV end-systolic volume < 82 ml/m2 Sens 55% Spec 92% Sens 74% Spec 82% Oosterhof et al. Circulation 2007
Guidelines for timing pulmonary valve replacement Class II a / level C PVR shold be considered in asymptomatic patients with severe PR when at least one of the following criteria is present: Decrease in objective exercise capacity Progressive RV dilatation (160 ml/m2 EDV) Progressive RV dysfunction Progressive tricuspid regurgitation Sustained atrial/ventricular arrhythmias ESC Guidelines 2010
Additional information by CMR Contrast-enhanced MR angiography : Anatomy RVOT Pulmonary arteries side branches Velocity encoded phase contrast cine: flow Regurgitant volume Differential lung perfusion RPA:LPA = 63% : 37% PR = 47% RF 1200ml
RVOT geometry Percutaneous valve replacement RVOT morphology circular conduit > 16 mm RVOT < 22mm Schievano et al. J Cardiovasc Magn Reson 2007
Additional information by CMR Gadolinium late enhancement: scars Risk stratification RV size and function QRS complex / arrhythmias QRS 172 msec
Assessment of fibrosis P<0.01 QRS (msec) 117±32 162 ±18 RVEDV (ml/m2) 118 ±34 175 ±42 RV EF% 54 ±10 43 ±6 Oosterhof et al. Radiology 2005 Copyright 2005, Radiological Society of North America, Inc
New Insights Natural course of RV dilatation 32 patients 45 patients Age at TOF repair 1.5 y Age at TOF repair 1.1 y (3.9) Follow up 10.8 y Follow up 4.5 y (16.5) Time interval CMR 3.2 y (1.5) Time interval CMR 3y (2) Navarini et al. AEPC 2011 Grothoff et al. Clin Res Cardiol 2011
Natural course of RV dilatation Navarini et al. AEPC 2011 Grothoff et al. Clin Res Cardiol 2011
Natural course of RV dilatation RV ESV ml/m2 160 140 120 Volume (ml) 100 80 60 40 20 First MR Navarini et al. AEPC 2011 P = 0.03 Second First MR MR
Regional dysfunction and late gadolinium enhancement Wald et al. Circulation 2009
Regional dysfunction and late gadolinium enhancement
Conclusions Take home messages Pulmonary regurgitation is the most frequent and insidious residual finding after TOF repair Right ventricular dilatation and dysfunction determine prognosis CMR is the ideal tool for quantifying parameters related to pulmonary regurgitation - High reproducibility of the data - Regurgitant volume more appropriate than fraction Additional findings can be shown by CMR and risk stratification given