Oral fluoroquinolone use and the risk of aortic and mitral valve regurgitation: a nationwide cohort study.

OBJECTIVE

This study aims to investigate whether oral fluoroquinolone use is associated with an increased risk of aortic and mitral valve regurgitation.

DESIGN

A nationwide cohort study based on linked healthcare register data encompassing patient characteristics, prescription data and cases of aortic and mitral valve regurgitation.

SETTING

Sweden, 2006-2018.

PARTICIPANTS

Study participants were adults aged 18-75 years. 794 588 courses of fluoroquinolones (88% ciprofloxacin) propensity score-matched (1:1) to an equal number of courses of penicillin V.

MAIN OUTCOME MEASURES: Aortic or mitral valve regurgitation leading to ED visit, hospitalisation or death. Cox regression was used to estimate HRs for the first incident of valve regurgitation within 120 days of treatment initiation. Subgroup and supplementary analyses included sex, age, first episode, surgery or death only, 356-day follow-up and analysis using amoxicillin as comparator drug.

RESULTS

There were 29 (incidence rate 0.5 per 1000 person-years) cases in the fluoroquinolone group compared with 43 (0.7 per 1000 person-years) cases in the penicillin V group during the main (1-30 days) follow-up period; corresponding to a HR 0.70 (95% CI 0.43 to 1.11). Analyses of subsequent time periods yielded results consistent with the main period: HR 1.06 (0.63-1.78) for days 31-60 and 0.90 (0.59-1.36) days 61-120. No significant differences were found in any of the subgroup- or supplementary analyses. The absolute risk difference was -17 (95% CI -33 to 6) cases of valve regurgitation per 1 000 000 courses of fluoroquinolones.

CONCLUSION

In a nationwide cohort study, there was no statistical support for an increase in the risk of mitral or aortic valve regurgitation associated with oral fluoroquinolone use.