The role and outcomes of new supraventricular tachycardia among patients with mild heart failure.

INTRODUCTION: We aimed to assess the predictors of new supraventricular tachycardia (SVT) and the association of new SVT with subsequent clinical outcomes among mild heart failure (HF) patients.

METHODS AND RESULTS: The study population comprised patients enrolled in MADIT-CRT, after exclusion of patients with atrial arrhythmias before enrollment (N = 325). Multivariate analysis was used to identify predictors of new-onset SVT and the association of time-dependent development of SVT with subsequent ventricular tachyarrhythmic events (VTEs), HF-hospitalizations, and death. SVT burden was categorized into three groups based on the number of episodes per patient; (a) Low <10, (b) Intermediate ≥10 but <20, and (c) High ≥20. During mean follow up of 3.4 ± 1.1 years, 41(3%) subjects developed new SVT. African American race, diastolic blood pressure (DBP) >80 mmHg and prior non sustained ventricular arrhythmia were independent predictors for SVT. Multivariate analysis showed that the development of time-dependent SVT was associated with a >4-fold increased risk for VTEs (HR = 4.3; 95% CI: 1.6-11.7; P = .004) and with a >6-fold increased risk for all-cause mortality (HR = 6.5; 95% CI: 2.3-18.7; P < .001), but not with HF hospitalizations (HR = 2.2; 95% CI: 0.7-7.2; P = .17). Intermediate, and high SVT-burden were each independent risk factors for death when compared with Low burden (HR = 9.1; P = .03, and HR = 19.4; P < .001; respectively).

CONCLUSIONS: In patients with mild HF, the development of new-onset SVT after device implantation is related to distinct baseline clinical and epidemiologic characteristics and is associated with a significant increase in subsequent adverse outcomes, including VTEs and death.