Outcomes with inpatient use of midodrine in patients with heart failure and kidney failure on maintenance dialysis.

Background: Midodrine, an FDA-approved medication for orthostatic hypotension, is also used off-label to manage hypotension in dialysis patients, including those with heart failure. However, in patients with reduced ejection fraction (HFrEF) and/or right heart failure, midodrine is potentially harmful. No known studies examine the safety of midodrine in hospitalised kidney failure patients with HF.

Methods: The TriNetX database was queried for hospitalised kidney failure patients with HFrEF and/or right heart failure who experienced hypotension (SBP < 110 mm Hg or MAP < 70 mm Hg). Excluding those needing critical care or vasopressors, we compared cohorts based on midodrine use, matching for comorbidities.

Results: Analysis showed patients on midodrine had a higher 6-month mortality risk ratio (RR 1.53, 95% CI 1.037 to 2.246) and Hazard Ratio (HR 1.54, 95% CI 1.022 to 2.317) compared to those not on midodrine, indicating an association with increased mortality.

Conclusion: This study illuminates the complexities in treating hospitalised patients with kidney failure and HF. Our findings, drawn from an exploratory analysis, indicate that inpatient midodrine use is associated with increased 6-month mortality. This may reflect deleterious effects from vasoconstriction and/or unmeasured confounders in this vulnerable population. This investigation, utilising TriNetX, was limited by access to deidentified aggregate data, preventing detailed exploration of specifics such as timing, dosage, and indications for midodrine use. Moreover, given its observational nature, cause-effect relationship cannot be established. Our findings indicate an increased mortality associated with midodrine use for hypotension, underscoring the need for further research and consideration of alternative strategies.