Income is associated with the probability to receive early coronary angiography after out-of-hospital cardiac arrest

Introduction: Low socioeconomic status has been associated with worse outcome after cardiac arrest. This study aims to investigate if patients´ income influences the probability to receive early coronary angiography in out-of-hospital cardiac arrest (OHCA) patients.

Methods: In this nationwide retrospective observational study, 3906 OHCA patients admitted alive and registered in the Swedish Registry for Cardiopulmonary Resuscitation were included. Individual data on income and educational level, prehospital parameters, coronary angiography results and comorbidity were linked from SWEDEHEART and other national registers.

Results: Patients were divided into quarters depending on their income level. In the unadjusted model there was a strong correlation between income level and rate of early coronary angiography where 35.5% of patients in the highest income quarters received early angiography compared to 15.4% in the lowest income quarters. When adjusting for educational level, sex, age, comorbidity and hospital type, there were still higher chance of receiving early coronary angiography with increasing income, OR 1.31 (CI 1.01-1.68) and 1.67 (CI 1.29-2.16) for the two highest income quarters respectively compared to the lowest income quarter. When adding potential mediators to the model (first recorded ECG rhythm by the EMS, location, response time, bystander cardiopulmonary resuscitation and if the arrest was witnessed) no difference in early angiography related to income level where found. The main mediator was first recorded ECG rhythm.

Conclusion: Income level is associated with the probability to undergo early coronary angiography in OHCA patients. This association seems to be mediated by the initial ECG rhythm.