Nonsteroidal Anti-inflammatory Drug Treatment for Postoperative Pericardial Effusion: A Multicenter Randomized, Double-Blind Trial

The incidence of asymptomatic pericardial effusion is high after cardiac surgery. Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely prescribed in this setting, but no study has assessed their efficacy.

To assess whether the NSAID diclofenac is effective in reducing postoperative pericardial effusion volume.

Multicenter randomized, double-blind, placebo-controlled study. (Clinical trials.gov registration number: NCT00247052)

5 postoperative cardiac rehabilitation centers.

196 patients at high risk for tamponade because of moderate to large persistent pericardial effusion (grade 2, 3, or 4 on a scale of 0 to 4, as measured by echocardiography) more than 7 days after cardiac surgery.

Random assignment at each site in blocks of 4 to diclofenac, 50 mg, or placebo twice daily for 14 days.

The main end point was change in effusion grade after 14 days of treatment. Secondary end points included frequency of late cardiac tamponade.

The initial mean pericardial effusion grade was 2.58 (SD, 0.73) for the placebo group and 2.75 (SD, 0.81) for the diclofenac group. The 2 groups showed similar mean decreases from baseline after treatment (−1.08 grades [SD, 1.20] for the placebo group vs. −1.36 (SD, 1.25) for the diclofenac group). The mean difference between groups was −0.28 grade (95% CI, −0.63 to 0.06 grade; P = 0.105). Eleven cases of late cardiac tamponade occurred in the placebo group and 9 in the diclofenac group (P = 0.64). These differences persisted after adjustment for grade of pericardial effusion at baseline, treatment site, and type of surgery.

The sample was not large enough to find small beneficial effects of diclofenac or assess the cardiovascular tolerance of diclofenac.

In patients with pericardial effusion after cardiac surgery, diclofenac neither reduced the size of the effusions nor prevented late cardiac tamponade.

French Society of Cardiology.