Long-term follow-up and risk assessment of arrhythmogenic right ventricular dysplasia/cardiomyopathy: personal experience from different primary and tertiary centres.

Objectives: Limited data are available on the course of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) because of the low frequency of this diagnosis. A long-term follow-up was analysed in typical ARVD/C patients from different primary and tertiary centres, and risk factors for sudden cardiac death (SCD) and end-stage heart failure were assessed.
Methods and Results: A total of 313 patients (197 males) with a mean age of 44.8 +/- 16.5 years were included, with symptoms including aborted SCD (7%), ventricular arrhythmias (47%), additional chest pain (42%), syncopes (17%), and atrial arrhythmias (12%); follow-up duration was 8.5 years. The total annual mortality rate was 0.3%, from SCD in 0.2% and heart failure in 0.1%. In symptomatic or high-risk patients, the annual rate of malignant ventricular arrhythmias was 6 and 9%, respectively. In multivariate analysis, a risk factor for SCD was left ventricular dysfunction. The annual heart failure rate was low at 0.5%; four patients died, two had heart transplants and one tricuspid reconstruction. Intrathoracic cardioverter-defibrillator (ICD) therapy was initiated in 35 patients. Adequate shocks after 6-72 months were delivered in 77%; in the majority aborted sudden death with documented ventricular fibrillation and unstable ventricular tachycardia were underlying arrhythmias.
Conclusions: The clinical course of ARVD/C is characterized by a high rate of recurrent malignant ventricular arrhythmias in initially symptomatic and high-risk cases, and is uneventful in primarily asymptomatic affected individuals. The spectrum of clinical symptoms represents a warning symptom initiating the so-called 'hot phase' of the disease in many cases. ICD treatment is highly effective in cases of aborted SCD and unstable ventricular tachycardia.