Michael L. Sabolinski

Early and Sustained Benefit on Event-Free Survival and Heart Failure Hospitalization From Fixed-Dose Combination of Isosorbide Dinitrate/Hydralazine Consistency Across Subgroups in the African-American Heart Failure Trial

Background— We previously reported that the fixed-dose combination of isosorbide dinitrate and hydralazine hydrochloride (FDC I/H) significantly decreased the risk of all-cause death and first hospitalization for heart failure (HF) and improved quality of life in patients with New York Heart Association class III or IV heart failure in the African-American Heart Failure Trial (A-HeFT). The current analyses further define the effect of FDC I/H on the timing of event-free survival (mortality or first hospitalization for HF) and time to first hospitalization for HF, as well as effects by subgroups and effects on cause-specific mortality. Methods and Results— Kaplan-Meier analyses of the 1050 A-HeFT patients on standard neurohormonal blockade demonstrated that FDC I/H produced a 37% improvement in event-free survival (P<0.001) and a 39% reduction in the risk for first hospitalization for HF (P<0.001). These benefits appeared to emerge early (at ≈50 days of treatment) and were sustained through the duration of the trial. Subgroup analyses of treatment effect by age, sex, baseline blood pressure, history of chronic renal insufficiency, presence of diabetes mellitus, cause of HF, and baseline medication usage demonstrated consistent beneficial effect of FDC I/H on the primary composite score and event-free survival across all subgroups. Mortality from pump failure was reduced by 75% (P=0.012). Conclusions— FDC I/H treatment of black patients with moderate to severe HF who were taking neurohormonal blockers produced early and sustained significant improvement in event-free survival and hospitalization for HF in the A-HeFT cohort, with significant reduction in mortality from cardiovascular and pump failure deaths. The treatment effects on the primary composite end point and event-free survival were consistent across subgroups.

Endothelial Nitric Oxide Synthase (NOS3) Polymorphisms in African Americans With Heart Failure : Results From the A-HeFT Trial

BACKGROUND Genetic heterogeneity at the endothelial nitric oxide synthase (NOS3) locus influences heart failure outcomes. The prevalence of NOS3 variants differs in black and white cohorts, but the impact of these differences is unknown. METHODS AND RESULTS Subjects (n = 352) in the Genetic Risk Assessment of Heart Failure (GRAHF) substudy of the African-American Heart Failure Trial were genotyped for NOS3 polymorphisms: -786 T/C promoter, intron 4a/4b, and Glu298Asp and allele frequencies and compared with a white heart failure cohort. The effect of treatment with fixed-dose combination of isosorbide dinitrates and hydralazine (FDC I/H) on event-free survival and composite score (CS) of survival, hospitalization, and quality of life (QoL) was analyzed within genotype subsets. In GRAHF, NOS3 genotype frequencies differed from the white cohort (P < .001). The -786 T allele was associated with lower left ventricular ejection fraction (LVEF) (P = .01), whereas the intron 4a allele was linked to lower diastolic blood pressure and higher LVEF (P = .03). Only the Glu298Asp polymorphism influenced treatment outcome; therapy with FDC I/H improved CS (P = .046) and QoL (P = .03) in the Glu298Glu subset only. CONCLUSIONS In black subjects with heart failure, NOS3 genotype influences blood pressure and left ventricular remodeling. The impact of genetic heterogeneity on treatment with FDC I/H requires further study.

Dysfunctional Corin I555(P568) Allele Is Associated With Impaired Brain Natriuretic Peptide Processing and Adverse Outcomes in Blacks With Systolic Heart Failure Results From the Genetic Risk Assessment in Heart Failure Substudy

Background—Corin, a transmembrane serine protease expressed in cardiomyocytes, cleaves pro–atrial natriuretic peptide and pro–brain natriuretic peptide (BNP) into biologically active peptide hormones. The minor corin I555(P568) allele, defined by the T555I and Q568P mutations, is common in persons of African ancestry and associated with increased risk for hypertension and cardiac concentric hypertrophy. The corin gene product containing the T555I and Q568P mutations has significantly reduced natriuretic peptide processing capacity. We hypothesized that the corin I555(P568) allele would be associated with adverse outcomes and impaired BNP processing in blacks with systolic heart failure. Methods and Results—This is a retrospective study of 354 subjects in the African American Heart Failure Trial Genetic Risk Assessment in Heart Failure substudy. In the corin variant group (n=50) compared with corin nonvariant group (n=300), BNP-32 (amino acids 77 to 108) was lower (190 pg/mL versus 340 pg/mL, P=0.007), but the ratio of unprocessed BNP1 to 108/processed BNP-32 was significantly higher (P=0.05). Stratified analyses were conducted because of evidence of significant interaction between the corin I555(P568) allele and treatment assignment. In the placebo arm, multivariable analysis demonstrated that the corin I555(P568) allele was associated with increased risk for death or heart failure hospitalization (relative risk 3.49; 95% CI, 1.45 to 8.39; P=0.005); however, in the treatment arm (fixed-dose combination isosorbide-dinitrate/hydralazine), the corin I555(P568) allele was not associated with adverse outcomes. Conclusions—We have identified a pharmacogenomic interaction in blacks with systolic heart failure. The corin I555(P568) allele is associated with an increased risk for death or heart failure hospitalization in patients receiving standard neurohormonal blockade, but the addition of fixed-dose combination isosorbide-dinitrate/hydralazine ameliorates this risk. A plausible mechanism for this pharmacogenomic interaction is the impaired processing of BNP in carriers of the corin I555(P568) allele as compared with noncarriers.

Cost-Effectiveness of Fixed-Dose Combination of Isosorbide Dinitrate and Hydralazine Therapy for Blacks With Heart Failure

Background— Fixed-dose combination of isosorbide dinitrate/hydralazine (ISDN/HYD) improved clinical outcomes in the African-American Heart Failure Trial (A-HeFT). We assessed the resource use, costs of care, and cost-effectiveness of ISDN/HYD therapy in the A-HeFT trial population. Methods and Results— We obtained resource use data from A-HeFT, assigning costs through the use of US federal sources. Excluding indirect costs, we summarized the within-trial experience and modeled cost-effectiveness over extended time horizons, including a US societal lifetime reference case. During the mean trial follow-up of 12.8 months, the ISDN/HYD group incurred fewer heart failure–related hospitalizations (0.33 versus 0.47 per subject; P=0.002) and shorter mean hospital stays (6.7 versus 7.9 days; P=0.006). When study drug costs were excluded, both heart failure–related and total healthcare costs were lower in the ISDN/HYD group (mean per-subject heart failure–related costs,

Dysfunctional Corin I555(P568) Allele Is Associated With Impaired Brain Natriuretic Peptide Processing and Adverse Outcomes in Blacks With Systolic Heart FailureCLINICAL PERSPECTIVE

5997 versus

Lack of Bioequivalence between Different Formulations of Isosorbide Dinitrate and Hydralazine and the Fixed-Dose Combination of Isosorbide Dinitrate/Hydralazine The V-HeFT Paradox

9144; P=0.04; mean per-subject total healthcare costs,

Exploring the Potential Synergistic Action of Spironolactone on Nitric Oxide-Enhancing Therapy: Insights From the African-American Heart Failure Trial

15 384 versus

Effects of ACE inhibitors or β-blockers in patients treated with the fixed-dose combination of isosorbide dinitrate/hydralazine in the african-american heart failure trial

19 728; P=0.03). With an average daily drug cost of

Effect of fixed-dose combined isosorbide dinitrate/hydralazine in elderly patients in the African-American heart failure trial.

6.38, ISDN/HYD therapy was dominant (reduced costs and improved outcomes) over the trial duration. Assuming that no additional benefits accrue beyond the trial, we project the cost-effectiveness of ISDN/HYD therapy using heart failure–related costs to be

Dysfunctional Corin I555 (P568) Allele is Associated with Impaired BNP Processing and Adverse Outcomes in African-Americans with Systolic Heart Failure: Results from the Genetic Risk Assessment in Heart Failure A-HeFT Sub-Study

16 600/life-year at 2 years after enrollment,