Biventricular pacing in patients with ICD: how many patients are possible candidates?

BACKGROUND: About 80 % of patients receiving an implantable cardioverter-defibrillator (ICD) due to life-threatening episodes of ventricular tachycardia (VT) or ventricular fibrillation (VF) have structural heart disease. ICD implantation reduces the risk of sudden cardiac death to less than 2 %. However, the major obstacle in these patients is chronic heart failure (CHF). Biventricular stimulation (BIV) has shown its efficiency as an alternative therapy in drug refractory CHF. METHODS: According to the InSync registry, we predefined possible indications for BIV as follows: complete branch bundle block (> 120 ms), left-ventricular ejection fraction (EF) II. We evaluated the number of patients presenting this indication at time of implant and during follow-up (FU) at our ICD clinic. RESULTS: Between 1992 and 1998, 360 patients were provided with an ICD (mean age 64.6 +/- 5.4 yrs, mean EF 37 +/- 14 % at implant, 82 % of patients with organic heart disease). Mean FU was 34 +/- 21 months. During FU 46 patients (13 %) died, 15 of these (33 %) presenting criteria for BIV. 33 patients died of heart failure, there was 1 sudden death and 12 patients died for non-cardiac reasons. 35 % of the patients who died of heart failure had an indication for BIV. CONCLUSIONS: About 10 % of ICD patients had an indication for BIV at time of implant. Over a mean FU period of 34 months, 16% of all patients presented an indication for BIV. Patients with an indication for BIV had a higher mortality rate and more frequent atrial fibrillation compared to patients without. With this data and the good clinical results after BIV-ICD implantation, we consider the implantation of a BIV-ICD system in every patient with appropriate indications.