New research has linked the prescribing of NSAIDs with an elevated risk of atrial fibrillation or flutter.
An analysis in the BMJ found exposure to non-aspirin NSAIDs – either non-selective NSAIDs or Cox-2 inhibitors – was associated with an increased risk of atrial fibrillation or flutter.
The association was strongest for new users, with between a 40% and 70% increase in relative risk compared with non-users.
NSAIDs have known cardiovascular risks, but the Danish researchers, who published the study online in the BMJ this week, said the study meant GPs should be aware of this addition risk as it ‘adds evidence that atrial fibrillation or flutter needs to be added to the cardiovascular risks to be considered when prescribing NSAIDs.’
The case-control study analysed 36,600 records held in a Danish hospital database for patients with a first diagnosis of atrial fibrillation or flutter between 1999 and 2008, compared with 326,000 matched controls.
Compared with no use, patients who were current users of non-selective NSAIDs – those who had already been exposed at the time of admission – was associated with a 17% increased risk of atrial fibrillation or flutter and Cox-2 inhibitors were associated with a 27% higher risk.
Among new users – those patients who were redeemed their first prescription within 60 days of the date of diagnosis – the incidence of atrial fibrillation or flutter was 46% higher in those taking non-selective NSAIDS and 71% higher in those taking cox-2 inhibitors, compared to non-users.
The adjusted incidence rates for the individual NSAIDs were similar (see box). The risk appeared highest in older people. Patients with chronic kidney disease, who had a 2.9-fold higher risk, or rheumatoid arthritis, who had a 2.5-fold higher risk, were at particularly increased risk when starting treatment with COX 2 inhibitors.
Professor Henrik Toft Sørensen, professor of clinical epidemiology at Aarhus University Hospital in Denmark, concluded: ‘In this large population based case-control study, we found that patients starting treatment with non-aspirin NSAIDs were at increased risk of atrial fibrillation or flutter compared with those not using NSAIDs.
‘The relative risk increase was equivalent to approximately four extra cases per year of atrial fibrillation per 1,000 new users of non-selective NSAIDS, and seven extra cases per year of atrial fibrillation per 1,000 new users of COX 2 inhibitors.’
BMJ 2011, online 5 July
Adjusted incidence rate ratio for atrial fibrillation or flutter among new drug users
Ibuprofen – 1.43
Naproxen – 1.44
Diclofenac – 1.73
Etodolac – 1.51
Celecoxib – 1.83
Rofecoxib – 1.59