IMPORTANCE Adults late after total correction of tetralogy of Fallot (TOF) are at risk for majorcomplications. Cardiovascular magnetic resonance (CMR) imaging is recommended toquantify right ventricular (RV) and left ventricular (LV) function. However, a commonly usedrisk model by Khairy et al requires invasive investigations and lacks CMR imaging to identifyhigh-risk patients.
OBJECTIVE To implement CMR imaging in noninvasive risk stratification to predict majoradverse clinical outcomes.
DESIGN, SETTING, AND PARTICIPANTS This multicenter study included 575 adult patients withTOF (4.083 patient-years at risk) from a prospective nationwide registry in whom CMR wasperformed. This study involved 5 tertiary referral centers with a specialized adult congenitalheart disease unit. Multivariable Cox hazards regression analysis was performed to determinefactors associated with the primary end point. The CMR variables were combined with thenoninvasive components of the Khairy et al risk model, and the C statistic of the finalnoninvasive risk model was determined using bootstrap sampling. The data analysis wasconducted from January to December 2016.
MAIN OUTCOMES AND MEASURES The composite primary outcome was defined as all-causemortality or ventricular arrhythmia, defined as aborted cardiac arrest or documentedventricular fibrillation and ventricular tachycardia (lasting 30 seconds or recurrentsymptomatic).
RESULTS Of the 575 patients with TOF, 57% were male, and the mean (SD) age was 31 (11)years. During a mean (SD) follow-up of 7.1 (3.5) years, the primary composite end pointoccurred in 35 patients, including all-cause mortality in 13 patients. Mean (SD) RV ejectionfraction (EF) was 44% (10%), and mean (SD) LV EF was 53% (8%). There was a correlationbetween RV EF and LV EF (R, 0.36; 95% CI, 0.29-0.44; P < .001). Optimal thresholds forventricular function (RV EF <30%: hazard ratio, 3.90; 95% CI, 1.84-8.26; P < .001 and LV EF<45%: hazard ratio, 3.23; 95% CI, 1.57-6.65; P = .001) were independently predictive inmultivariable analysis. Both thresholds were included in a point-based noninvasive risk model(C statistic, 0.75; 95% CI, 0.63-0.85) and combined with the noninvasive components of theKhairy et al risk model.
CONCLUSIONS AND RELEVANCE In patients with repaired TOF, biventricular dysfunction onCMR imaging was associated with major adverse clinical outcomes. The quantified thresholds(RV EF <30% and LV EF <45%) may be implemented in noninvasive risk stratification.
- CONGENITAL HEART-DISEASE
- PULMONARY VALVE-REPLACEMENT
- REPAIRED TETRALOGY
- PREOPERATIVE THRESHOLDS