Inefficient Ventriculoarterial Coupling in Fontan Patients: A Cardiac Magnetic Resonance Study
The ventriculoarterial coupling (VAC) ratio, the ratio of arterial elastance (Ea) to ventricular end-systolic elastance (Ees), reflects cardiovascular efficiency. Little is known about this ratio in patients who have undergone the Fontan procedure. Our aim was to assess the VAC ratio in a cohort of Fontan patients using a cardiac magnetic resonance (CMR) method, and to examine its relation to outcomes. We retrospectively assessed VAC from CMR data on 195 Fontan patients (age 19.6 ± 10.7 years) and 42 controls (age 15.2 ± 2.2 years). The VAC ratio was calculated as Ea/Ees (Ea = mean arterial blood pressure (MBP)/ventricular stroke volume; Ees = MBP/end-systolic volume). Compared with controls, Fontan patients had lower body surface area-adjusted median Ees (1.54 vs. 2.4, p < 0.001) and Ea (1.35 vs. 1.48, p = 0.01), and a higher median VAC ratio (0.88 vs. 0.62, p < 0.001). After a median follow-up of 4 years (range 1–10), 20 patients reached a composite endpoint of death or heart transplant listing. On multivariable modeling, being in the lowest tertile of the VAC ratio was independently associated with the composite endpoint (odds ratio 11.39, p = 0.02), and inclusion of the VAC ratio in the model improved prediction compared to traditional risk factors. In patients without ventricular dilation, the VAC ratio was the only factor predictive of the composite endpoint (p = 0.02). In conclusion, we found evidence for inefficient ventriculoarterial coupling in Fontan patients. The VAC ratio improved prediction of outcomes and was especially useful in patients without ventricular dilation. Further investigation into the clinical significance of ventriculoarterial coupling in this patient population is warranted.
KeywordsSingle ventricle Fontan Cardiac magnetic resonance Pathophysiology Prognosis
Compliance with Ethical Standards
Conflict of interest
The authors declare that they have no competing interests.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. For this type of study formal consent is not required.
- 1.Anderson PA, Sleeper LA, Mahony L, Colan SD, Atz AM, Breitbart RE, Gersony WM, Gallagher D, Geva T, Margossian R, McCrindle BW, Paridon S, Schwartz M, Stylianou M, Williams RV, Clark BJ, 3rd (2008) Contemporary outcomes after the Fontan procedure: a Pediatric Heart Network multicenter study. J Am Coll Cardiol 52:85–98CrossRefPubMedPubMedCentralGoogle Scholar
- 2.d’Udekem Y, Iyengar AJ, Galati JC, Forsdick V, Weintraub RG, Wheaton GR, Bullock A, Justo RN, Grigg LE, Sholler GF, Hope S, Radford DJ, Gentles TL, Celermajer DS, Winlaw DS (2014) Redefining expectations of long-term survival after the Fontan procedure: twenty-five years of follow-up from the entire population of Australia and New Zealand. Circulation 130:S32–S38CrossRefPubMedGoogle Scholar
- 4.Rathod RH, Prakash A, Powell AJ, Geva T (2010) Myocardial fibrosis identified by cardiac magnetic resonance late gadolinium enhancement is associated with adverse ventricular mechanics and ventricular tachycardia late after Fontan operation. J Am Coll Cardiol 55:1721–1728CrossRefPubMedPubMedCentralGoogle Scholar
- 8.Chirinos JA (2013) Ventricular-arterial coupling: invasive and non-invasive assessment. Art Res 7:2–14Google Scholar
- 26.Truong U, Patel S, Kheyfets V, Dunning J, Fonseca B, Barker AJ, Ivy D, Shandas R, Hunter K (2015) Non-invasive determination by cardiovascular magnetic resonance of right ventricular-vascular coupling in children and adolescents with pulmonary hypertension. J Cardiovasc Magn Reson 17:81CrossRefPubMedPubMedCentralGoogle Scholar
- 29.Rathod RH, Prakash A, Powell AJ, Geva T (2009) Myocardial fibrosis identified by cardiac magnetic resonance delayed enhancement is associated with ventricular dysfunction and nonsustained ventricular tachycardia after Fontan operation. J Am Coll Cardiol 53:A356Google Scholar
- 31.Blalock SE, Banka P, Geva T, Powell AJ, Zhou J, Prakash A (2013) Interstudy variability in cardiac magnetic resonance imaging measurements of ventricular volume, mass, and ejection fraction in repaired tetralogy of Fallot: a prospective observational study. J Magn Reson Imaging 38:829–835CrossRefPubMedGoogle Scholar
- 33.Williams RV, Margossian R, Lu M, Atz AM, Bradley TJ, Jay Campbell M, Colan SD, Gallagher D, Lai WW, Pearson GD, Prakash A, Shirali G, Cohen MS, Pediatric Heart Network I (2013) Factors impacting echocardiographic imaging after the Fontan procedure: a report from the pediatric heart network Fontan cross-sectional study. Echocardiography 30:1098–1106PubMedPubMedCentralGoogle Scholar
- 34.Margossian R, Schwartz ML, Prakash A, Wruck L, Colan SD, Atz AM, Bradley TJ, Fogel MA, Hurwitz LM, Marcus E, Powell AJ, Printz BF, Puchalski MD, Rychik J, Shirali G, Williams R, Yoo SJ, Geva T, Pediatric Heart Network I (2009) Comparison of echocardiographic and cardiac magnetic resonance imaging measurements of functional single ventricular volumes, mass, and ejection fraction (from the Pediatric Heart Network Fontan Cross-Sectional Study). Am J Cardiol 104:419–428CrossRefPubMedPubMedCentralGoogle Scholar
- 36.Atz AM, Zak V, Mahony L, Uzark K, Shrader P, Gallagher D, Paridon SM, Williams RV, Breitbart RE, Colan SD, Kaltman JR, Margossian R, Pasquali SK, Allen K, Lai WW, Korsin R, Marino BS, Mirarchi N, McCrindle BW (2014) Survival data and predictors of functional outcome an average of 15 years after the Fontan procedure: the pediatric heart network Fontan cohort. Congenit Heart Dis 10:E30CrossRefPubMedPubMedCentralGoogle Scholar