2017 HSR&D/QUERI National Conference

4003 — Clinical Effectiveness of Hydralazine-Isosorbide Dinitrate in VHA Heart Failure Patients by Race

Lead/Presenter: Boback Ziaeian, COIN - Los Angeles
All Authors: Ziaeian B (VA GLA) Fonarow GC (UCLA) Heidenreich PA (VA Palo Alto)

Objectives:
Among African American patients with heart failure (HF) with reduced ejection fraction (HFrEF), the combination of hydralazine and isosorbide dinatrate (H-ISDN) in addition to usual care was found to improve quality of life, lower HF hospitalization and mortality rates in the A-HEFT randomized control trial. Few studies have evaluated the effectiveness in a real-world setting. Here we observe the benefits of therapy in the VA HFrEF population.

Methods:
VA patients with a primary HF admission between 2007 to 2013 were screened for inclusion in an observational cohort. Inclusion criteria included African American race, left ventricular ejection fraction < 40%, and received regular medications through the VA pharmacy. Patients were excluded if they had contraindications to receiving H-ISDN, a creatinine greater 2.0, or intolerance to angiotensin converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARB). Hazard ratios (HR) were calculated for patients who received H-ISDN 6 months prior to admission compared to those that did not receive H-ISDN using inverse probability weighting of propensity scores and a time to death analysis with 18 months of follow-up. Propensity scores were generated using patient characteristics, vitals, lab values, and hospital characteristics.

Results:
The final cohort included 5,168 African American HF patients (age 65.19) with 15.2% treated with H-ISDN prior to index admission. After 18 months of follow-up from index admission, there were 1,275 reported deaths (24.7%). The unadjusted HR was 0.88, (p = 0.11), adjusted HR using inverse probability weighting of propensity scores were 0.85, (p = 0.006). Adjusted mortality at 18 months was 22.1% for H-ISDN treatment and 25.2% for untreated (p = 0.009).

Implications:
H-ISDN remains underutilized in African American patients with HFrEF for unclear reasons. In this observational cohort, we find a significant mortality advantage associated with H-ISDN use in African American HFrEF patients at 18 months when adjusting for patient and hospital factors using an inverse probability weighted propensity score model.

Impacts:
H-ISDN is under-utilized for African American HFrEF patients. We observe evidence for a sustained benefit associated with usage.