VENTICULAR ARRHYTHMIA FOLLOWING SUCCESSFUL MYOCARDIAL REVASCULARIZATION - INCIDENCE, PREDICTORS AND PREVENTION

Objectives: We estimated the risk of sudden cardiac death (SCD), from a spontaneous episode of ventricular arrhythmia (VT/VF), after a succe ssful surgical myocardial revascularization (coronary artery bypass gr afting; CABG) procedure. Predictors of these events were identified, a nd long term benefits of the prophylactic regimes, that were used to c ontrol these events, were evaluated. Methods: We selected 8642 consecu tive patients, who had undergone an isolated and first time CABG proce dure, between 1/3/1980 and 1/3/1995. A standard hazard function model (1) was used for statistical analysis. Efficacy of the prophylactic re gimes, was examined in a group of 350 high risk patients, with a preop erative left ventricular ejection fraction 30% or less, who were recen tly operated since 1/1/1988. Electrophysiologic (EP) guided prophylaxi s was used in 92 (26%) patients, who had survived a documented episode of SCD, and remaining 258 patients were maintained on antiarrhythmic medication on an empirical basis. A sequential EP evaluation was perfo rmed, when indicated. Results: During an early phase of hazard, which mainly lasted for up to 3 months after CABG, incremental risk factors were preoperative LVEF 30% or less (P = 0.0007) and preoperative episo des of VT/VF (P = 0.04). This phase was followed by a constant phase w ith a low risk of the events, which merged into a slowly rising late p hase after 6 years. EP guided prophylaxis, reduced the risk of SCD in high risk patients (P = 0.03). A sequential EP evaluation, helped to d etect the problems of drug resistance and a cross over from non-sustai ned to sustained runs of VT/VF. Conclusions: Despite a successful CABG surgery, risk of VT/VF persists. A routine EP evaluation before and a fter a CABG procedure is recommended in all patients with a poor left ventricular function. (C) 1998 Published by Elsevier Science B.V. All rights reserved.