Impact of the electrocardiographic pattern in V1, aVL and I following cardiac resynchronization therapy at 2 years

Abstract Funding Acknowledgements Type of funding sources: None. Introduction There is little evidence regarding if the electrocardiographic pattern following CRT has impact on morbidity and mortality. In a previous study, a specific group of patterns in three leads of the ECG (Rs in V1, Qr in aVL or rS in I) was associated with lower incidence of the composite endpoint of death from any cause and heart failure hospitalization at 1 year. Purpose In this historical cohort study we analyzed if the specific pattern (Rs in V1, Qr in aVL or rS in I) was associated with outcomes at 2 years follow up. Methods Patients with CRT devices were consecutively included from January 2012 to April 2019. The primary endpoint was a composite of death from any cause and heart failure hospitalization at 2 years. Secondary endpoints included the individual components of the primary endpoint at 2 years. Survival analysis was performed using Kaplan-Meier test, comparing survival graphics through Log-Rank test. For multivariate analysis, Cox regression was performed. Results We included 111 patients. Baseline characteristics are reported in Table 1. Presence of any of the three patterns was not significantly associated with the primary endpoint (p=0.182). Patients who presented any of these patterns had not a significantly lower incidence of death from any cause (p=0.303), but had a significantly lower incidence of HF hospitalization (4.7% vs. 17.6%, hazard ratio 0.207, 95% confidence interval 0.046-0.93, p=0.04). Previous atrial fibrillation was independently associated with a higher incidence of primary and secondary endpoints. QRS duration postimplantation was independently associated with incidence of the primary endpoint. Conclusion The presence of the patterns Rs in V1, Qr in aVL or rS in I is an independent predictor of reduced HF hospitalizations at 2 years in patients with CRT. Previous atrial fibrillation and QRS duration were also associated with outcomes.