Comparison of Circadian Variation for In-Hospital Versus Out-of-Hospital Sudden Cardiac Arrest Survivors

https://doi.org/10.1016/j.amjcard.2021.08.034Get rights and content

Several studies have reported circadian periodicity of sudden cardiac arrest (SCA). It remains unclear to what extent this circadian rhythm is influenced by variation in patients’ activities. One way to elucidate this is to compare patients with out-of-hospital cardiac arrests (OHCAs) with those with in-hospital cardiac arrests (IHCAs). We therefore examined the presence of a circadian pattern of SCA in a large cohort of OHCA and IHCA survivors. A total of 1,433 consecutive survivors of SCA in the Pittsburgh area from 2002 to 2012 were included. Patient demographics, including clinical histories and details of SCA, were collected. The distribution of SCA throughout the day was tested for differences using the chi-square test. Of the 1,224 patients analyzed, 706 had IHCA and 518 OHCA. We observed a nadir of SCA in the nighttime hours between 12 a.m. and 6 a.m. in both IHCA and OHCA groups (p <0.001), although this pattern was more blunted in the IHCA group. Patients who had an SCA in the nighttime window had more co-morbidities (p = 0.01). The circadian pattern was noted to be absent in patients with higher co-morbidity burden in IHCA only. In conclusion, the typical pattern of nighttime nadir in SCA is observed in patients with both OHCA and IHCA but is blunted in the hospital and especially in sicker patients. This suggests a common mechanistic pathway of SCA transcending differences in physical activities of patients and a difference in how co-morbidities interact with the timing of SCA in the inpatient setting.

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Methods

Patients with SCA who were cared for at affiliated hospitals of the University of Pittsburgh Medical Center in Western Pennsylvania from 2002 to 2012 were included in this analysis. A total of 3,426 consecutive records of patients were identified using International Classification of Disease, 9th edition, codes for ventricular fibrillation (427.41), ventricular tachycardia (427.1), ventricular flutter (427.42), and cardiac arrest (427.5). Only patients aged 18 years and older, those without

Results

The baseline characteristics of the study cohort are listed in Table 1. Compared with OHCA survivors (n = 706), IHCA survivors (n = 518) were older, of higher body mass index, and had more co-morbid conditions with a higher CCI (p <0.001). Specifically, IHCA survivors had higher prevalence of atrial fibrillation, diabetes mellitus, hypertension, and chronic kidney disease and were more likely to be prescribed aspirin and β blockers. Compared with IHCA survivors, OHCA survivors had higher serum

Discussion

We demonstrated a clear circadian pattern of SCA in both hospitalized and community settings, suggesting an underlying common mechanistic pathway that transcends differences in physiology and activity levels between these 2 settings. Although the circadian pattern of SCA has been well documented in OHCA, it has rarely been examined previously in the IHCA population. One recent large study based on the American Heart Association's multicenter Get With The Guidelines-Resuscitation registry

CRediT Author Statement

Yicheng Tang: Data collection, analysis, and manuscript writing; Tarryn Tertulien: Data collection and analysis; Aditya Bhonsale: critical review of the manuscript; Krishna Kancharla: critical review of the manuscript; N.A. Mark Estes III: critical review of the manuscript; Sandeep K. Jain: critical review of the manuscript; Samir Saba: Concept of study, data analysis, and critical review of the manuscript.

Disclosures

Dr. Saba reports receiving research support from Boston Scientific and Abbott Inc.

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