Retrospective Cohort Study: As-Needed Blood Pressure Medications Associated With Increased AKI and Other Adverse Outcomes in Hospitalized Veterans
8 Dec, 2024 | 21:34h | UTCBackground: Inpatient asymptomatic blood pressure (BP) elevations are common, and clinicians frequently use as-needed BP medications to rapidly lower BP values. However, there is limited evidence supporting this practice, and abrupt BP reductions may increase the risk of ischemic events, including acute kidney injury (AKI).
Objective: To examine whether as-needed BP medication use during hospitalization is associated with increased risk of AKI and other adverse outcomes compared to no as-needed use.
Methods: This retrospective cohort study used a target trial emulation and propensity score matching. Adults hospitalized for ≥3 days in non-ICU VA hospital wards from 2015-2020, who received at least one scheduled BP medication within the first 24 hours and had at least one systolic BP reading >140 mm Hg, were included. Patients were categorized into two groups: those receiving at least one as-needed BP medication (oral or IV) and those receiving only scheduled BP medications. The primary outcome was time-to-first AKI event. Secondary outcomes included a >25% drop in systolic BP within 3 hours and a composite of myocardial infarction (MI), stroke, or death.
Results: Among 133,760 veterans (mean age 71.2 years; 96% male), 21% received as-needed BP medications. As-needed BP medication use was associated with a 23% higher risk of AKI (HR=1.23; 95% CI, 1.18-1.29). The IV route showed a particularly pronounced AKI risk (HR=1.64). Secondary analyses indicated a 1.5-fold increased risk of rapid BP reduction and a 1.69-fold higher rate of the composite outcome (MI, stroke, death) among as-needed users.
Conclusions: In a large, national cohort of hospitalized veterans, as-needed BP medication use was associated with increased AKI risk and other adverse outcomes. These findings suggest that routine as-needed BP medication use for asymptomatic BP elevations may be harmful.
Implications for Practice: Clinicians should carefully reconsider the use of as-needed BP medications in the inpatient setting, especially in older individuals or those with significant cardiovascular risk. Given the lack of clear benefit and potential for harm, greater caution and potentially more conservative approaches are warranted.
Study Strengths and Limitations: Strengths include a large, nationally representative sample and robust analytic methods. Limitations include the retrospective design, potential residual confounding, and limited generalizability to non-veteran or surgical populations. While causal inferences cannot be made, the findings strongly support the need to question current practice.
Future Research: Prospective, randomized trials are needed to determine the optimal management of asymptomatic inpatient hypertension and to assess whether avoiding or reducing as-needed BP medication use improves clinical outcomes.