PO-05-163 INCIDENCE AND RHYTHM PRESENTATION OF IN-HOSPITAL VERSUS OUT-OF-HOSPITAL SUDDEN CARDIAC ARREST AND PREDICTORS OF READMISSION AT 90 DAYS

Abstract

Sudden cardiac arrest (SCA) may culminate in sudden cardiac death (SCD) if resuscitation efforts are unsuccessful or absent. The pathogenesis and system of care for in-hospital and out-of-hospital cardiac arrest (IHCA and OHCA) are different. We sought to determine predictors of readmission in these patients presenting with SCA and surviving to discharge. All patients >18 years of age presenting with sudden cardiac arrest from 2016-2019 were included. Data were abstracted using the International Classification of Diseases 10th Revision-Clinical Modification from the Nationwide Readmissions Database (NRD). Patient demographics, presence of comorbidities, presenting rhythm, and predictors of readmission were evaluated. Out of 51,998,206 admissions between 2016 to 2019, 35,050 (0.07%) presented with SCA. IHCA was commoner than OHCA [21,347 (60.9%) vs 13,703 (39.1%)]. Patients presenting with OHCA were younger [67 vs 69 years, p <0.0001] and had overall lower systemic comorbidities [Charlson’s comorbidity index (CCI) – OHCA: 2.0 (1.0-3.0) vs IHCA: 2.0 (1.0-4.0) points, P<0.0001]. Pulseless electrical activity (PEA) was the predominant presenting rhythm overall but much higher in the OHCA group [overall: 68.6%, IHCA: 51.5% vs OHCA: 95.4%, p<0.0001]. Ventricular arrhythmia (VA) [ventricular tachycardia (VT), ventricular fibrillation (VF)] were commoner in IHCA as compared to OHCA [OHCA: 2,878 (29.9%) vs IHCA: 6,761 (70.1%), p<0.0001]. Of the patients getting admitted with SCA, 26,080 (74.41%) died at the first admission, with a higher mortality in the OHCA group [IHCA 15,690 (73.5% mortality) vs OHCA 10,390 (75.82% mortality), p<0.0001]. At 90-day follow-up, a much higher percentage of the OHCA group had PEA as compared to IHCA [OHCA: 3,012 (90.9%) vs. IHCA: 2,573 (45.5%), p<0.0001] similar to the first admission. Young age predicted higher readmissions in the IHCA group whereas the presence of diabetes mellitus and renal diseases predicted higher readmission rates in both the groups (P<0.0001). PEA was the predominant presenting rhythm irrespective of the type of cardiac arrest (IHCA or OHCA) at the first admission as well as at readmission. Younger patients (<60 years) with IHCA were more likely to get readmitted, which is alarming and needs a proper evaluation of this cohort to prevent recurrences and reduce mortality among sudden cardiac arrest survivors.