Patients with obstructive pulmonary disease have an increased risk of ecg documented out-of-hospital cardiac arrest

Background: Signals exist that patients with obstructive lung disease (OPD) have an increased risk of out of hospital cardiac arrest (OHCA), but evidence is scarce. Objectives: 1. To determine whether patients with OPD have an increased risk of OHCA. 2. To identify subgroups with a high risk of cardiac arrest. Methods: A prospective case-control study was performed, with 1,372 cases suffering from OHCA and 6068 age, gender, and OHCA-date matched controls. To ensure that OHCA resulted from cardiac causes, electrocardiogram (ECG) documentation of ventricular tachycardia/ fibrillation (the most common causes of cardiac arrest) was required. Patients were considered to have OPD if they had at least 2 prescriptions of any medication with ATC code R03 within 1 year prior to OHCA date. Conditional logistic regression analysis was used to examine the risk for cardiac arrest in relation to OPD. Stratified analysis were performed regarding age category, gender, cardiovascular comorbidity, and disease severity (number of different respiratory drugs used within 6 months before OHCA date). Results: Patients with OPD had an increased risk of OHCA compared to patients without OPD (adjusted (adj.) OR 1.4 [1.2-1.6], p <0.001). The risk of OHCA was higher among females (adj. OR 1.8 [1.3-2.6], p = 0.001) than males (adj. OR 1.2 [1.0-1.5], p = 0.032). The risk of OHCA was comparable in the different age categories. Patients with more severe OPD (>3 respiratory drugs) had a higher risk of OHCA (adj. OR 1.8,(1.2- 2.8), p = 0.004) than patients with moderate disease (three drugs, adj. OR 1.3 (0.9-1.8), p = 0.150) or mild disease (1-2 drugs, adj. OR 1.4 (1.1-1.7), p = 0.007). OPD patients with cardiovascular disease (adj. OR 3.7 [3.0-4.5], p <0.001) had a higher risk of OHCA than OPD patients without cardiovascular disease (adj. OR 1.2 [0.9-1.7], p = 0.299) or patients without OPD, but with cardiovascular disease (adj. OR 2.6 [2.2-3.0], p <0.001). Conclusions: Patients with OPD have an increased risk of OHCA compared to patients without OPD. Of the patients with obstructive lung disease, women, patients with severe disease and patients with concomitant cardiovascular disease have the highest risk.