Abstract 10916: Lower Framingham Risk Score are Associated With Morning Peak in the Circadian Variation of ST Elevation Myocardial Infarction Onset
Introduction: There are few studies analyzing the influences of coronary risk factors on the circadian variation of ST elevation myocardial infarction (STEMI).
Hypothesis: We assessed the hypothesis that coronary risk factors could be associated with circadian variation of STEMI.
Methods and Results: Two hundred and ninety-three patients were admitted to Miyazaki Prefectural Nobeoka Hospital, Japan with STEMI from April 2008 to March 2011. Among them, the onset time of STEMI was identified in 280 patients [age; 70.5±11.7, male; 68%, hypertension (HT); 80%, diabetes mellitus (DM); 28%, current smoking (cSM); 33%, Framingham risk score (FRS); 8.77±3.28]. The hourly circadian variation of STEMI onset showed 2 peaks around 09:00 and 23:00. The day was divided into six 4-h periods, with the morning peak between 08:00-12:00 (77/ 280, 28%, p<0.01). When we divided patients into three groups; the morning incidence group (08:00-12:00), the nighttime incidence group (20:00-24:00) and other time incidence group, the frequency of HT in morning incidence group was significantly lower than in nighttime incidence group (68% vs. 87%). FRS in morning incidence group was significantly lower than that in nighttime incidence group and other time incidence group (7.95±3.47 vs. 9.14±2.89 vs. 9.06±3.25). Multivariate logistic regression analysis revealed HT was independent variables associated with the morning peak of STEMI [odds ratio (OR); 0.43 (95% confidence interval); 95%-CI 0.23-0.83, p=0.01]. The rate of cSM was independent variables associated with the nighttime incidence of STEMI (OR; 1.96 95%-CI; 1.01-3.80, p=0.04). In subgroup analysis, non-HT group, non-smoking group and non-DM group have no significant morning peak of STEMI. Finally, logistic regression analysis revealed lower FRS was significantly associated with the morning peak of STEMI (OR; 1.12, 95%-CI; 1.02-1.21, p=0.01).
Conclusion: Lower FRS and non-HT are associated with the morning peak in the circadian variation of STEMI onset. cSM is associated with the nighttime incidence of STEMI. Coronary risk factors is associated with circadian variation of STEMI and morning incidence of STEMI might be affected by unknown pathogenesis rather than classical coronary risk factors.
- © 2013 by American Heart Association, Inc.