Unnatural history of tetralogy of fallot: Prospective follow-up of 40 years after surgical correction

Background —Prospective data on long-term survival and clinical outcome beyond 30 years after surgical correction of Tetralogy of Fallot (ToF) is non-existing. Methods and Results —This longitudinal cohort study consists of the 144 ToF patients who underwent surgical repair at age <15 years between 1968-1980 in our center. They are investigated every ten years. Cumulative survival (data available in 136 patients) was 72% after 40 years. Late mortality was due to heart failure and ventricular fibrillation. Seventy-two of 80 (90%) eligible survivors participated in the third in-hospital investigation, consisting of electrocardiography, Holter, echocardiography, cardiopulmonary exercise testing, NT-proBNP measurement, CMR including dobutamine stress testing and the SF-36 questionnaire. Median follow-up was 36 (range 31-43) years. Cumulative event-free survival was 25% after 40 years. Subjective health status was comparable to the normal Dutch population. Although systolic right and left ventricular function declined, the peak exercise capacity remained stable. There was no progression of aortic root dilation. A prior shunt operation, low temperature during surgery and early postoperative arrhythmias were found to predict late mortality (HR 2.9, 1.1 and 2.5 respectively). Increase in QRS-duration, deterioration of exercise tolerance and ventricular dysfunction did not predict mortality. Insertion of a transannular patch was a predictor for late arrhythmias (HR 4.0 [95%CI 1.2-13.4]). Conclusions —Although many patients needed a reoperation or developed arrhythmias, late mortality was low and the clinical condition and subjective health status of most patients remained good. Prior shunt, low temperature during surgery and early postoperative arrhythmias were found to predict late mortality.