Changes in loop diuretic use following mitral valve surgery for mitral regurgitation according to age: a nationwide cohort study

Loop diuretic use (LDU) may provide complementary information on post-operative heart failure (HF) burden after mitral valve surgery (MVS).

We investigated changes in LDU before and after MVS for mitral regurgitation (MR) and assessed post-operative HF admission according to age.

Using Danish nationwide registries, we identified patients aged ≥18 years discharged after first-time MVS for MR between 1996 and 2022. LDU was assessed from redeemed prescriptions before surgery and at post-operative landmarks. HF admission within 5 years was estimated with death as a competing risk. Among 6840 patients, LDU was 46.2% before surgery and declined among survivors to 27.0% at 12–15 months and 23.7% at 36–39 months. Pre-operative use was more frequent with increasing age, ranging from 27.9% in patients aged 18–49 years to 64.3% in those aged ≥80 years. Postoperatively, LDU remained common, ranging from 13.5% to 41.6% at 12–15 months and from 11.9% to 35.4% at 36–39 months across age groups. The 5-year cumulative incidence of HF admission was 20.9% (95% CI: 20.0–22.0%) overall and increased across age groups, from 13.9% to 27.4%. Pre-operative LDU was associated with higher 5-year mortality irrespective of recorded HF status.

LDU declined after MVS for MR but remained common, particularly among older patients, and showed an age-related pattern consistent with hospital admission for HF.