Midodrine and clinical outcomes in patients on maintenance hemodialysis

Patients on hemodialysis often experience intradialytic hypotension (IDH), contributing to increased cardiovascular disease and mortality. Midodrine, an α-1 adrenergic receptor agonist, is commonly prescribed for IDH treatment or prevention. However, the effects of midodrine on clinical outcomes remain unclear. We aimed to evaluate the impact of midodrine use on clinical outcomes in patients on maintenance hemodialysis. This retrospective study evaluated patients according to midodrine prescriptions based on a dataset from the hemodialysis quality assessment program and Health Insurance Review and Assessment. Propensity score matching was employed to minimize bias in baseline characteristics. The Cox regression model was used to estimate the hazard ratio (HR) and confidence interval (CI) for all-cause mortality and cardiovascular events (CVEs). Approximately 9.6% of 71,540 patients were prescribed midodrine. The numbers of patients in the No-proscription and Midodrine groups were 20,305 and 6,887 after matching, respectively. The 5-year patient survival rates in the No-prescription and Midodrine groups were 62.6% and 58.0%, respectively (P < 0.001). Midodrine use was associated with an increased risk of all-cause mortality (adjusted HR: 1.17, 95% CI 1.13-1.22, P < 0.001). A high dose of midodrine was associated with a higher HR for mortality than that in a No-prescription or low dose of midodrine. The risk of CVE between the groups was not significantly different. This study showed that midodrine use was associated with a dose-dependent increase in all-cause mortality. Clinicians should actively search for and treat comorbidities and risk factors for IDH in patients requiring midodrine, especially frequent dosing. The findings should be interpreted with caution due to the observational nature of the study and should be validated in future prospective studies incorporating comprehensive IDH data.