Abstract 13630: Association Between Arrhythmia Burden During Clinical Exercise Testing and All-Cause Mortality

Abstract

Introduction: Arrhythmias commonly occur during clinical exercise stress testing (EST), however there are limited data on prognostic significance, particularly differences between individuals with minor versus significant arrhythmia burden. Hypothesis: We hypothesized that significant but not minor arrhythmia burden during EST would be predictive of future all-cause mortality. Methods: Adults who underwent clinically indicated EST at Mayo Clinic Rochester between September 1993 and April 2017 were included and followed-up until March 2021 using the National Death Index to ascertain survival status. Expert clinician coding pertaining to arrhythmia burden during EST were used to group individuals (see Table 1 ). Cox proportional hazard models adjusted for known predictors of exercise-induced arrhythmias, were used to test the association of arrhythmia burden with all-cause mortality. Results: A total of 30796 individuals were included (age: 55±14yrs; female: 36%; Table 1 ). Mean follow-up was 8.8±3.6yrs, with a total of 2516 deaths. Arrhythmia during EST was associated with all-cause mortality compared with no arrhythmia (HR: 1.72; 95% CI: 1.58-1.88; p<0.001), however significant arrhythmia showed greater association compared with minor arrhythmia (HR: 2.07; 95% CI: 1.81-2.38; p<0.001). Both minor and significant arrhythmia during EST were significant predictors of all-cause mortality compared with no arrhythmia ( Figure, Table 2 ), however, after model adjustments, only significant arrhythmia was associated with all-cause mortality (HR: 1.40; 95% CI: 1.21-1.63; p<0.001) ( Table 2 ). Conclusions: After multivariate adjustment, significant arrhythmia burden during EST showed a 40% increased future risk of all-cause mortality, Conversely, adjusting for age and sex attenuated the effect of minor arrhythmia burden during EST on incidence of death. These results highlight the clinical significance of arrhythmia burden during exercise testing.