Aims: Ventricular dysfunction or structural alteration of either ventricle is a well-established risk factor for sudden death (SD). Ebstein anomaly (EA) can present with both right and left heart abnormalities; however, predictors of SD have not been described. We therefore sought to characterize the incidence and risk factors of SD among a large cohort of patients with EA.
Methods and results: All EA patients who underwent evaluation at a high-volume institution over a 4-decade period were retrospectively reviewed. Clinical variables, cardiovascular surgical procedure(s), and cause of death were recorded. Sudden death incidence from birth and following tricuspid valve (TV) surgery were estimated using the Kaplan-Meier method. Cox regression analysis was used to identify clinical and surgical predictors of SD. The cohort comprised of 968 patients [mean age 25.3 years, 41.5% male; 79.8% severe EA, 18.6% accessory pathway, 0.74% implantable cardioverter-defibrillator (ICD) placement]. The 10-, 50-, and 70-year cumulative incidences of SD from birth were 0.8%, 8.3%, and 14.6%, respectively. Prior ventricular tachycardia [hazard ratio (HR) 6.37, P < 0.001)], heart failure (HR 5.64, P < 0.001), TV surgery (HR 5.94, P < 0.001), syncope (HR 2.03, P = 0.019), pulmonic stenosis (HR 3.42, P = 0.001), and haemoglobin > 15 g/dL (HR 2.05, P = 0.026) were multivariable predictors of SD. In a similar subgroup analysis of patients who underwent TV surgery, all of the above factors except syncope were significantly associated with post-operative SD on multivariable analysis.
Conclusion: Patients with EA are at significant risk for SD. Key clinical SD predictors identified can aid in risk stratification and potentially guide primary prevention ICD implantation.