Non-steroidal anti-inflammatory drugs and risk of pulmonary embolism in patients with inflammatory joint disease-results from the nationwide Norwegian Cardio-rheuma registry.

Aims: Patients with inflammatory joint diseases (IJD), including rheumatoid arthritis (RA), psoriatic arthritis (PsA), and axial spondyloarthritis (axSpA) have increased rates of pulmonary embolism (PE). Non-steroidal anti-inflammatory drugs (NSAIDs) use is associated with PE in the general population. Our aim was to evaluate the association between NSAIDs use and PE in IJD patients.

Methods and results: Using individual-level registry data from the whole Norwegian population, including data from the Norwegian Patient Registry and the Norwegian Prescription Database, we: (1) evaluated PE risk in IJD compared to non-IJD individuals, (2) applied the self-controlled case series method to evaluate if PE risks were associated with use of traditional NSAIDs (tNSAIDs) and selective cox-2 inhibitors (coxibs). After a one-year wash-out period, we followed 4 660 475 adults, including 74 001 with IJD (RA: 39 050, PsA: 20 803, and axSpA: 18 591) for a median of 9.0 years. Crude PE incidence rates per 1000 patient years were 2.02 in IJD and 1.01 in non-IJD individuals. Age and sex adjusted hazard ratios for PE events were 1.57 for IJD patients compared to non-IJD. Incidence rate ratios (IRR) [95% confidence interval (CI)] for PE during tNSAIDs use were 0.78 (0.64-0.94, P = 0.010) in IJD and 1.68 (1.61-1.76, P < 0.001) in non-IJD. IRR (95% CI) for PE during coxibs use was 1.75 (1.10-2.79, P = 0.018) in IJD and 2.80 (2.47-3.18, P < 0.001) for non-IJD.

Conclusion: Pulmonary embolism rates appeared to be higher in IJD than among non-IJD subjects in our study. Traditional NSAIDs may protect against PE in IJD patients, while coxibs may associated with increased PE risk.