Abstract Body (Do not enter title and authors here): Background:
Coronary artery dissection (CADx), either spontaneous or iatrogenic, carries high mortality associated with it. Tachycardia induces a shear stress on the blood vessel; thus, controlling heart rate is cornerstone for the treatment of dissecting blood vessels. We hypothesize that Afib, by inducing shear stress, can lead to increased risk or worsen an existing coronary artery dissection. With this study, we aim to compare the impact of Afib on CADx mortality and morbidity outcomes and healthcare utilization using the NIS databse.
Methods:
We performed a retrospective cohort study using the 2021 NIS database, which is a survey-weighted sample of pan-US hospital admissions comprising of over 6 million observations. Patients with CADx (spontaneous + iatrogenic) were identified (using ICD-10 CM codes) and stratified based on presence of Afib/Aflutter(AF) which served as the primary exposure. Logistic regression was used to calculate the odds ratio(OR) for all-cause mortality and cardiac arrest and ventricular fibrillation/flutter (primary outcome variables). Comorbidities were accounted for using the Charlson comorbidity index. The OR for mechanical circulatory support (Impella and balloon pump) were secondary outcomes. Length of stay(LOS) and total cost were calculated and compared between the two groups.
Results:
Among the 10,255 patients with CADx, 15.6% (1,538) had concurrent AF. While the overall mortality for patients with CADx was 7.2% (738), the crude mortality was higher in the afib group (14.1% vs 5.8%, Chi², p<0.001). Cardiac arrest (23% vs 14%), impella (9% vs 4%) and balloon pump (12% vs 8%) use were also seen more frequently in the afib group. When adjusted for age, sex, race and comorbidities the risk for cardiac arrest remained significantly increased (aOR: 1.7, CI: 1.2-24, p<0.001) while all-cause-mortality (p=0.055), impella (p=0.092) and balloon pump use (p=0.7) became non-significant. The mean LOS and TOTCHG for afib group was significantly higher (8.1 vs 4.6 days) and $260,828 vs $155,686.
Conclusion:
In our study, new onset or preexisting AF in patients with coronary artery dissection was associated with increased risk of malignant ventricular arrhythmias and cardiac arrest. This risk did not translate into increased all cause mortality likely due to prompt identification and termination of these arrhythmias. However, AF was associated with an increase in mean LOS and total cost of care.