Ventricular size and function assessed by cardiac MRI predict major adverse clinical outcomes late after tetralogy of Fallot repair

Background: Factors associated with impaired clinical status in a cross-sectional study of patients with repaired tetralogy of Fallot (TOF) have been reported previously. Objectives: To determine independent predictors of major adverse clinical outcomes late after TOF repair in the same cohort during follow-up evaluated by cardiac magnetic resonance (CMR). Methods: Clinical status at latest follow- up was ascertained in 88 patients (median time from TOF repair to baseline evaluation 20.7 years; median follow- up from baseline evaluation to most recent follow-up 4.2 years). Major adverse outcomes included (a) death; (b) sustained ventricular tachycardia; and (c) increase in NYHA class to grade III or IV. Results: 22 major adverse outcomes occurred in 18 patients (20.5%): death in 4, sustained ventricular tachycardia in 8, and increase in NYHA class in 10. Multivariate analysis identified right ventricular (RV) end-diastolic volume Z >= 7 (odds ratio (OR)= 4.55, 95% confidence interval (CI) 1.10 to 18.8, p= 0.037) and left ventricular (LV) ejection fraction < 55% (OR= 8.05, 95% CI 2.14 to 30.2, p= 0.002) as independent predictors of outcome with an area under the receiver operator characteristic curve of 0.850. LV ejection fraction could be replaced by RV ejection fraction < 45% in the multivariate model. QRS duration >= 180 ms also predicted major adverse events but correlated with RV size. Conclusions: In this cohort, severe RV dilatation and either LV or RV dysfunction assessed by CMR predicted major adverse clinical events. This information may guide risk stratification and therapeutic interventions.