Risk of malignant outcome in patients with wolff-parkinson-white syndrome: results of 28-years prospective electrophysiological follow-up study

Purpose: The Wolff-Parkinson-White (WPW) syndrome can be associated with sudden death (SD), thus risk assessment (RA) with electrophysiological (EP) testing (EPT) is a mandatory to identify patients (pts) requiring catheter ablation (CA). Our prospective study aimed to identify and treat WPW pts at high arrhythmogenic risk (HAR), and to evaluate the predictive value of transesophageal EPT (TEEPT) for RA, evaluation of treatment efficacy, and longitudinal EP follow up (F-up) of untreated athletes/pts. Methods: 318 WPW pts referred to us between 1985 and 2013. Antegrade effective refractory period (ERP) of accessory pathway (AP) and of the atrioventricular node (AVN), Wenckebach point (WP), shortest preexcited RR intervals (SPERRI) during atrial fibrillation (AF) and/or atrial pacing, and inducibility of supraventricular arrhythmias (SVTA) were assessed, at rest (in supine and upright position) and during effort. Results: Out of 318 pts, 275 untreated pts (53.8% athletes) were enrolled. AP’s/AVN’s ERP and SPERRIs varied as a function of autonomic modulation and were shorter in the 128 symptomatic (S) compared with 147 asymptomatic (AS) pts, (p<0.05). One or more sustained SVTA were inducible in 128/275 pts (46.54%), and AF in 70 pts. During the F-up (12.3±5.2 pts years), out of 57 pts classified at HAR, 37 were ablated. Before CA availability, two S pts, with inducible antidromic AVRT and AF (SPERRI <180 msec at rest), refused surgery and died suddenly (at rest). Both had self-discontinued antiarrhythmic therapy (AAD). Other 18 HAR pts were treated with AAD, without complications. Overall mortality was (0.06%/year of F-up). Among 218 pts classified at low (198) or medium (20) risk, 21 pts underwent elective CA for fit-for-duty requirements. Periodical reevaluation was performed, if clinically or legally required (overall 922 F-up TEEPTs). 56 refused a second study (TEEPT2), which was performed in 161 pts. Compared to TEEPT1, EP data of untreated pts who underwent TEEPT2 were highly reproducible. Clinical F-up data of untreated pts remained unchanged in 79.4%. Only 5.3% of initially AS became S, whereas 41.8% of S became AS. Conclusions: This study confirms good long-term prognosis in WPW pts. Our two casualties were avoidable, given the correct HAR identification provided by TEEPT, if surgery was accepted or CA available. No other patient had complications during the F-up, even though 72.2% of athletes were allowed to continue competitive sports activity. TEEPT is an efficient method which can minimize invasivity for EP RA of WPW pts and for longitudinal F-up of professional athletes.