Abstract 1891: Mortality After CRT: a Synergetic Effect Between Ventricular Remodeling and Reduced Frequency of Ventricular Arrhythmias. The InSync ICD Italian Registry
Introduction: It is currently debated whether cardiac resynchronization therapy (CRT) has an effect on the burden of ventricular arrhythmias (VA). We investigated whether the reverse remodeling after CRT may reduce the occurrence of VA.
Methods: The study included 398 patients enrolled in the InSync ICD Italian Registry, treated with CRT-D and with a follow-up of at least 12 months. Spontaneous VA detected by the device were reviewed and validated.
Results: After 6 months of follow-up no VA episodes occurred in 319 patients (group 1), while VA episodes persisted in the remaining 79 (group 2). At baseline, clinical and echocardiographic characteristics of the two groups were comparable: NYHA class (2.9±0.6 vs. 3.0±0.7), QRS width (166±31ms vs. 163±34ms), ejection fraction (26±7% vs. 26±6%), LVEDV (251±98ml vs. 226±45ml), LVESV (182±84ml vs. 158±38ml) (All p=NS). At 6 month visit, ventricular remodeling was apparent only in group 2 pts: LVEDV (200±83ml, p=0.042 vs. Baseline), LVESV (133±65ml, p=0.002 vs. Baseline). No changes were evident in group 2 pts: LVEDV (216±69ml, p=0.769 vs. Baseline), LVESV (160±59ml, p=0.521 vs. Baseline). The long-term survival from all-cause death resulted higher in group 1 pts (Log-rank test: p=0.032). (Figure⇓)
Conclusions: In patients treated with CRT, a reduction of ventricular arrhythmic events occurs during the initial 12 months following implant and is correlated with the degree of ventricular remodeling induced by the therapy. Patients demonstrating the remission of arrhythmic episodes will have better survival and more pronounced long term improvements.