Researchers from the UK and Italy performed a combined analysis (known as a "meta-analysis") of all the available randomised trials that compared a COX 2 inhibitor with placebo, or a COX 2 inhibitor with a traditional NSAID, and had recorded serious cardiovascular events. By including data from 138 trials among 140,000 patients, this meta-analysis provides a much more reliable estimate of the cardiovascular risks of these drugs, since individual trials were too small to study this question.
The study showed, as expected, that, COX 2 inhibitors were associated with an increased risk of vascular events, mainly heart attack. Unfortunately, there were insufficient data to reliably assess whether these risks were dose dependent, or whether the risks might differ among aspirin and non-aspirin users.
But the study also showed that high doses of two of the NSAIDs studied, diclofenac and ibuprofen, were associated with a similar increase in the risk of vascular events to COX 2 inhibitors, although the risks of high doses of another NSAID, naproxen, were smaller.
However, the average increased risk of vascular events was modest among the people studied in the trials: For every 1,000 people taking an NSAID or COX 2 inhibitor, around three extra people per year would have a vascular event, most likely a heart attack.
The authors conclude that very large randomised trials are needed to identify which anti-inflammatory drug regimens minimise serious cardiovascular and gastrointestinal problems.
An accompanying editorial discusses other options for treating chronic pain and suggests that doctors work with their patients to choose the best solutions for them.