A prospective study of the METS-IR index to predict arrhythmia risk in middle-aged adults

Background: Higher METS-IR has been shown to be associated with a higher risk of major adverse cardiovascular events, but data are lacking regarding cardiac arrhythmias. Objectives: The aim of this study was to assess the association between METS-IR and atrial fibrillation/flutter, ventricular arrhythmia and bradyarrhythmia. Methods: Data from the Atherosclerosis Risk in Communities study spanning 1987 to 2013 was utilized for this analysis. METS-IR scores were assessed at baseline (1987-1989) and arrhythmia episodes were identified using ICD-9 codes. Multivariate-adjusted Cox proportional hazard models were constructed to evaluate the relationship between METS-IR and arrhythmia risk, with dose-response analyses conducted. In addition, we analyzed the predictive value of METS-IR for arrhythmias. Results: Over a mean follow-up of 21.9 years, 2493 cases of AF, 688 cases of bradyarrhythmia, and 1315 cases of ventricular arrhythmia were recorded. Each interquartile range increase in METS-IR was associated with a 49% higher risk of atrial fibrillation(P<0.001), 29% higher risk of bradyarrhythmia(P<0.001), and 42% higher risk of ventricular arrhythmia(P<0.001). After correction for relevant confounders, the METS-IR index was significantly and positively associated with the risk of new-onset atrial fibrillation, bradyarrhythmia, and ventricular arrhythmia (P overall<0.05, P for non-linearity>0.05). Most of the results of the subgroup analyses were not significantly different. The inclusion of METS-IR in the base model improves the predictive value of the risk of arrhythmogenesis. Conclusions: There is a significant association between METS-IR and increased risk of arrhythmias.