Abstract 18095: Resting Heart Rate is a Significant Predictor of Sudden Death in the General Population
Introduction: In cohort studies, increased resting heart rate is a risk factor for cardiovascular mortality as well as sudden death after myocardial infarction. Hypothesis: We hypothesized that resting heart rate is a determinant of sudden cardiac arrest (SCA) in the community.
Methods: Cases of SCA with coronary artery disease (CAD) from an ongoing population-based study in the Northwest US were included (population approximately one million). Controls were residents with CAD without SCA. Subjects were required to have a 12-lead ECG with measurement of resting heart rate. For cases, the ECG closest and unrelated to the occurrence of SCA was evaluated and showed sinus rhythm (89%), sinus arrhythmia (2%), atrial fibrillation (8%) and atrial flutter (1%). Independent samples t-tests and Pearson's chi-square tests were used for case-control comparisons of continuous and categorical variables, respectively. Logistic regression was used to estimate the association of heart rate with SCA.
Results: A total of 692 cases of SCA and 536 controls, age ≥35 years and with available ECG, were enrolled from 2002 to 2009. Cases were older than controls (71 yrs vs. 66 yrs, p<0.0001) but there was no difference in gender distribution (p=0.40). Cases had significantly higher resting heart rate compared to controls (79 bpm vs. 70 bpm, p<0.0001). Controls had more ECGs in sinus rhythm than cases (94% vs. 86%) whereas cases had more atrial fibrillation compared to controls (11% vs. 4%) (p=0.0001). Both male and female cases had higher heart rate compared to controls (78 bpm and 79 bpm vs. 69 bpm and 71 bpm, respectively, p<0.0001). Similarly, young and old (≥ 60 yrs) cases had higher heart rate compared to controls (81 bpm and 78 bpm vs. 71 bpm and 69 bpm, respectively, p<0.0001). Heart rate was a significant predictor of SCA after adjustment for age and gender [OR for 10 bpm increase = 1.37; 95% CI (1.27 - 1.48)]. Similar results were found when analysis was limited to ECGs with sinus rhythm [OR for 10 bpm increase = 1.42; 95% CI (1.31 - 1.54)].
Conclusions: These findings in the broad community validate the strong association between resting heart rate and sudden death identified from cohort studies. Mechanisms of this association merit further evaluation.
- © 2010 by American Heart Association, Inc.