Azithromycin use poses acute heart failure, mortality risks for some COVID-19 patients

Exposure to azithromycin may put patients with COVID‐19 and history of cardiovascular disease (CVD) at higher risks of acute heart failure and death, as reported in a study.

For the study, researchers used data from the ISACS‐COVID‐19* registry. A total of 2,934 patients (mean age 65 years, 43 percent women) with a confirmed diagnosis of SARS‐CoV‐2 infection comprised the sample, including 793 patients who were exposed to azithromycin within 24 hours of hospital admission and 2,141 patients who received only standard care (control).

Compared with the control group, the azithromycin group were much older (standardized difference ≥0.10) and had higher rates of dementia (13.7 percent vs 10.2 percent) but were less likely to present with radiograph or computed tomography signs of interstitial pneumonia (61.9 percent vs 68.3 percent). Moreover, the azithromycin group tended to receive hydroxychloroquine (28.5 percent vs 11.5 percent) more frequently and antiviral medications such as remdesivir (7.4 percent vs 11.4 percent), antiplatelet agents (17.8 percent vs 26.9 percent), and diuretics (27.4 percent vs 45.4 percent) less frequently.

Overall, 1,066 patients (36.4 percent) had pre-existing CVD. A total of 617 patients (21.0 percent) died, and 253 (8.6 percent) had acute heart failure.

Analyses showed that among patients with pre-existing CVD, azithromycin therapy was associated with an excess risk of acute heart failure (risk ratio [RR], 1.48, 95 percent confidence interval [CI], 1.06–2.06) compared with standard of care. Furthermore, azithromycin use did not lower the risk of all‐cause 30‐day mortality (RR, 0.94, 95 percent CI, 0.69–1.28).

Among patients without prior CVD, on the other hand, azithromycin use was associated with reduced odds of death (RR, 0.57, 95 percent CI, 0.42–0.79) and did not contribute to a significant increase in acute heart failure (RR, 1.23, 95 percent CI, 0.75–2.04) compared with standard of care.  

Of note, pre-existing CVD was associated with increased risk of acute heart failure and death (odds ratio, 2.28, 95 percent CI, 1.34–3.90) compared with no CVD history (p=0.01 for interaction).

*International Survey of Acute Coronavirus Syndromes‐COVID‐19