Acetylsalicylic acid cuts out-of-hospital cardiac arrest risk

The use of acetylsalicylic acid (ASA) reduces the risk of out-of-hospital cardiac arrest (OHCA) in both sexes, but appears to have a stronger effect on women, a recent study has found. Meanwhile, clopidogrel does not seem to affect OHCA risk.

Drawing from the Amsterdam Resuscitation Registry, researchers conducted a population-based case-control study that included 772 OHCA patients who had documented ventricular tachycardia/ventricular fibrillation. Data on the use of antiplatelet drugs were also retrieved. A parallel group of non-OHCA controls was also included in the analysis.

Multivariable logistic regression analysis showed that the use of ASA reduced the likelihood of OHCA by 40 percent overall (adjusted odds ratio [OR], 0.6, 95 percent confidence interval [CI], 0.5–0.8).

This effect was stronger in women, who saw a 70-percent drop in OHCA risk after ASA (adjusted OR, 0.3, 95 percent CI, 0.2–0.6). Risk reduction in men, on the other hand, was at 30 percent (adjusted OR, 0.7, 95 percent CI, 0.5–0.95). The sex interaction was statistically significant (p=0.021).

In addition, the use of carbasalate calcium likewise reduced OHCA risk in women (adjusted OR, 0.5, 95 percent CI, 0.3–0.9) but not in men (adjusted OR, 1.3, 95 percent CI, 0.96–1.7; p=0.005 for interaction). Clopidogrel did not affect OHCA risk in either sex.

“The observational nature of our study allows for reporting statistical associations, and, as such, we could only detect associations without proving causality. Furthermore, our subgroup analysis was based on small sample sizes, which may have resulted in possible low statistical power,” the researchers said.

“Hence, our findings should be interpreted with caution. Future studies with available data on therapeutic indication are needed to confirm and support our findings,” they added.