Temporal Relation Between Myocardial Fibrosis and Heart Failure With Preserved Ejection Fraction: Association With Baseline Disease Severity and Subsequent Outcome.

Importance: Among myriad changes occurring during the evolution of heart failure with preserved ejection fraction (HFpEF), cardiomyocyte-extracellular matrix interactions from excess collagen may affect microvascular, mechanical, and electrical function. Objective: To investigate whether myocardial fibrosis (MF) is similarly prevalent both in those with HFpEF and those at risk for HFpEF, similarly associating with disease severity and outcomes. Design, Setting, and Participants: Observational cohort study from June 1, 2010, to September 17, 2015, with follow-up until December 14, 2015, at a cardiovascular magnetic resonance (CMR) center serving an integrated health system. Consecutive patients with preserved systolic function referred for CMR were eligible. Cardiovascular magnetic resonance was used to exclude patients with cardiac amyloidosis (n = 19). Exposures: Myocardial fibrosis quantified by extracellular volume (ECV) CMR measures. Main Outcome and Measures: Baseline BNP; subsequent hospitalization for heart failure or death. Results: Of 1174 patients identified (537 [46%] female; median [interquartile range {IQR}] age, 56 [44-66] years), 250 were "at risk" for HFpEF given elevated brain-type natriuretic peptide (BNP) level; 160 had HFpEF by documented clinical diagnosis, and 745 did not have HFpEF. Patients either at risk for HFpEF or with HFpEF demonstrated similarly higher prevalence/extent of MF and worse prognosis compared with patients with no HFpEF. Among those at risk for HFpEF or with HFpEF, the actual diagnosis of HFpEF was not associated with significant differences in MF (median ECV, 28.2%; IQR, 26.2%-30.7% vs 28.3%; IQR, 25.5%-31.4%; P = .60) or prognosis (log-rank 0.8; P = .38). Over a median of 1.9 years, 61 patients at risk for HFpEF or with HFpEF experienced adverse events (19 hospitalization for heart failure, 48 deaths, 6 with both). In those with HFpEF, ECV was associated with baseline log BNP (disease severity surrogate) in multivariable linear regression models, and was associated with outcomes in multivariable Cox regression models (eg, hazard ratio 1.75 per 5% increase in ECV, 95% CI, 1.25-2.45; P = .001 in stepwise model) whether grouped with patients at risk for HFpEF or not. Conclusions and Relevance: Among myriad changes occurring during the apparent evolution of HFpEF where elevated BNP is prevalent, MF was similarly prevalent in those with or at risk for HFpEF. Conceivably, MF might precede clinical HFpEF diagnosis. Regardless, MF was associated with disease severity (ie, BNP) and outcomes. Whether cells and secretomes mediating MF represent therapeutic targets in HFpEF warrants further evaluation.

Efficacy and Safety of Spironolactone in Acute Heart Failure: The ATHENA-HF Randomized Clinical Trial.

Importance: Persistent congestion is associated with worse outcomes in acute heart failure (AHF). Mineralocorticoid receptor antagonists administered at high doses may relieve congestion, overcome diuretic resistance, and mitigate the effects of adverse neurohormonal activation in AHF. Objective: To assess the effect of high-dose spironolactone and usual care on N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels compared with usual care alone. Design, Setting, and Participants: This double-blind and placebo (or low-dose)-controlled randomized clinical trial was conducted in 22 US acute care hospitals among patients with AHF who were previously receiving no or low-dose (12.5 mg or 25 mg daily) spironolactone and had NT-proBNP levels of 1000 pg/mL or more or B-type natriuretic peptide levels of 250 pg/mL or more, regardless of ejection fraction. Interventions: High-dose spironolactone (100 mg) vs placebo or 25 mg spironolactone (usual care) daily for 96 hours. Main Outcomes and Measures: The primary end point was the change in NT-proBNP levels from baseline to 96 hours. Secondary end points included the clinical congestion score, dyspnea assessment, net urine output, and net weight change. Safety end points included hyperkalemia and changes in renal function. Results: A total of 360 patients were randomized, of whom the median age was 65 years, 129 (36%) were women, 200 (55.5%) were white, 151 (42%) were black, 8 (2%) were Hispanic or Latino, 9 (2.5%) were of other race/ethnicity, and the median left ventricular ejection fraction was 34%. Baseline median (interquartile range) NT-proBNP levels were 4601 (2697-9596) pg/mL among the group treated with high-dose spironolactone and 3753 (1968-7633) pg/mL among the group who received usual care. There was no significant difference in the log NT-proBNP reduction between the 2 groups (-0.55 [95% CI, -0.92 to -0.18] with high-dose spironolactone and -0.49 [95% CI, -0.98 to -0.14] with usual care, P = .57). None of the secondary end point or day-30 all-cause mortality or heart failure hospitalization rate differed between the 2 groups. The changes in serum potassium and estimated glomerular filtration rate at 24, 48, 72, and 96 hours. were similar between the 2 groups. Conclusions and Relevance: Adding treatment with high-dose spironolactone to usual care for patients with AHF for 96 hours was well tolerated but did not improve the primary or secondary efficacy end points. Trial Registration: clinicaltrials.gov Identifier: NCT02235077.

Effect of Oral Iron Repletion on Exercise Capacity in Patients With Heart Failure With Reduced Ejection Fraction and Iron Deficiency: The IRONOUT HF Randomized Clinical Trial.

IMPORTANCE: Iron deficiency is present in approximately 50% of patients with heart failure with reduced left ventricular ejection fraction (HFrEF) and is an independent predictor of reduced functional capacity and mortality. However, the efficacy of inexpensive readily available oral iron supplementation in heart failure is unknown. OBJECTIVE: To test whether therapy with oral iron improves peak exercise capacity in patients with HFrEF and iron deficiency. DESIGN, SETTING, AND PARTICIPANTS: Phase 2, double-blind, placebo-controlled randomized clinical trial of patients with HFrEF (<40%) and iron deficiency, defined as a serum ferritin level of 15 to 100 ng/mL or a serum ferritin level of 101 to 299 ng/mL with transferrin saturation of less than 20%. Participants were enrolled between September 2014 and November 2015 at 23 US sites. INTERVENTIONS: Oral iron polysaccharide (n = 111) or placebo (n = 114), 150 mg twice daily for 16 weeks. MAIN OUTCOMES AND MEASURES: The primary end point was a change in peak oxygen uptake (V̇o2) from baseline to 16 weeks. Secondary end points were change in 6-minute walk distance, plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, and health status as assessed by Kansas City Cardiomyopathy Questionnaire (KCCQ, range 0-100, higher scores reflect better quality of life). RESULTS: Among 225 randomized participants (median age, 63 years; 36% women) 203 completed the study. The median baseline peak V̇o2 was 1196 mL/min (interquartile range [IQR], 887-1448 mL/min) in the oral iron group and 1167 mL/min (IQR, 887-1449 mL/min) in the placebo group. The primary end point, change in peak V̇o2 at 16 weeks, did not significantly differ between the oral iron and placebo groups (+23 mL/min vs -2 mL/min; difference, 21 mL/min [95% CI, -34 to +76 mL/min]; P = .46). Similarly, at 16 weeks, there were no significant differences between treatment groups in changes in 6-minute walk distance (-13 m; 95% CI, -32 to 6 m), NT-proBNP levels (159; 95% CI, -280 to 599 pg/mL), or KCCQ score (1; 95% CI, -2.4 to 4.4), all P > .05. CONCLUSIONS AND RELEVANCE: Among participants with HFrEF with iron deficiency, high-dose oral iron did not improve exercise capacity over 16 weeks. These results do not support use of oral iron supplementation in patients with HFrEF. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT02188784.

Rationale and Design of the ATHENA-HF Trial: Aldosterone Targeted Neurohormonal Combined With Natriuresis Therapy in Heart Failure.

Although therapy with mineralocorticoid receptor antagonists (MRAs) is recommended for patients with chronic heart failure (HF) with reduced ejection fraction and in post-infarction HF, it has not been studied well in acute HF (AHF) despite being commonly used in this setting. At high doses, MRA therapy in AHF may relieve congestion through its natriuretic properties and mitigate the effects of adverse neurohormonal activation associated with intravenous loop diuretics. The ATHENA-HF (Aldosterone Targeted Neurohormonal Combined with Natriuresis Therapy in Heart Failure) trial is a randomized, double-blind, placebo-controlled study of the safety and efficacy of 100 mg/day spironolactone versus placebo (or continued low-dose spironolactone use in participants who are already receiving spironolactone at baseline) in 360 patients hospitalized for AHF. Patients are randomized within 24 h of receiving the first dose of intravenous diuretics. The primary objective is to determine if high-dose spironolactone, compared with standard care, will lead to greater reductions in N-terminal pro-B-type natriuretic peptide levels from randomization to 96 h. The secondary endpoints include changes in the clinical congestion score, dyspnea relief, urine output, weight change, loop diuretic dose, and in-hospital worsening HF. Index hospital length of stay and 30-day clinical outcomes will be assessed. Safety endpoints include risk of hyperkalemia and renal function. Differences among patients with reduced versus preserved ejection fraction will be determined. (Study of High-dose Spironolactone vs. Placebo Therapy in Acute Heart Failure [ATHENA-HF]; NCT02235077).

A contemporary appraisal of the heart failure epidemic in Olmsted County, Minnesota, 2000 to 2010.

IMPORTANCE: Heart failure (HF) is commonly referred to as an epidemic, posing major clinical and public health challenges. Yet, contemporary data on its magnitude and implications are scarce. OBJECTIVE: To evaluate recent trends in HF incidence and outcomes overall and by preserved ejection fraction (HFpEF) or reduced ejection fraction (HFrEF). DESIGN, SETTING, AND PARTICIPANTS: Incidence rates of HF in Olmsted County, Minnesota (population, approximately 144,248), between January 1, 2000, and December 31, 2010, were assessed. MAIN OUTCOMES AND MEASURES: Patients identified with incident HF (n = 2762) (mean age, 76.4 years; 43.1% male) were followed up for all-cause and cause-specific hospitalizations (through December 2012) and death (through March 2014). RESULTS: The age- and sex-adjusted incidence of HF declined substantially from 315.8 per 100,000 in 2000 to 219.3 per 100,000 in 2010 (annual percentage change, -4.6), equating to a rate reduction of 37.5% (95% CI, -29.6% to -44.4%) over the last decade. The incidence declined for both HF types but was greater (interaction P = .08) for HFrEF (-45.1%; 95% CI, -33.0% to -55.0%) than for HFpEF (-27.9%; 95% CI, -12.9% to -40.3%). Mortality was high (24.4% for age 60 years and 54.4% for age 80 years at 5 years of follow-up), frequently ascribed to noncardiovascular causes (54.3%), and did not decline over time. The risk of cardiovascular death was lower for HFpEF than for HFrEF (multivariable-adjusted hazard ratio, 0.79; 95% CI, 0.67-0.93), whereas the risk of noncardiovascular death was similar (1.07; 95% CI, 0.89-1.29). Hospitalizations were common (mean, 1.34; 95% CI, 1.25-1.44 per person-year), particularly among men, and did not differ between HFpEF and HFrEF. Most hospitalizations (63.0%) were due to noncardiovascular causes. Hospitalization rates for cardiovascular causes did not change over time, whereas those for noncardiovascular causes increased. CONCLUSIONS AND RELEVANCE: Over the last decade, the incidence of HF declined substantially, particularly for HFrEF, contrasting with no apparent change in mortality. Noncardiovascular conditions have an increasing role in hospitalizations and remain the most frequent cause of death. These results underscore the need to augment disease-centric management approaches with holistic strategies to reduce the population burden of HF.

Diuretic strategies in patients with acute decompensated heart failure.

BACKGROUND: Loop diuretics are an essential component of therapy for patients with acute decompensated heart failure, but there are few prospective data to guide their use. METHODS: In a prospective, double-blind, randomized trial, we assigned 308 patients with acute decompensated heart failure to receive furosemide administered intravenously by means of either a bolus every 12 hours or continuous infusion and at either a low dose (equivalent to the patient's previous oral dose) or a high dose (2.5 times the previous oral dose). The protocol allowed specified dose adjustments after 48 hours. The coprimary end points were patients' global assessment of symptoms, quantified as the area under the curve (AUC) of the score on a visual-analogue scale over the course of 72 hours, and the change in the serum creatinine level from baseline to 72 hours. RESULTS: In the comparison of bolus with continuous infusion, there was no significant difference in patients' global assessment of symptoms (mean AUC, 4236±1440 and 4373±1404, respectively; P=0.47) or in the mean change in the creatinine level (0.05±0.3 mg per deciliter [4.4±26.5 µmol per liter] and 0.07±0.3 mg per deciliter [6.2±26.5 µmol per liter], respectively; P=0.45). In the comparison of the high-dose strategy with the low-dose strategy, there was a nonsignificant trend toward greater improvement in patients' global assessment of symptoms in the high-dose group (mean AUC, 4430±1401 vs. 4171±1436; P=0.06). There was no significant difference between these groups in the mean change in the creatinine level (0.08±0.3 mg per deciliter [7.1±26.5 µmol per liter] with the high-dose strategy and 0.04±0.3 mg per deciliter [3.5±26.5 µmol per liter] with the low-dose strategy, P=0.21). The high-dose strategy was associated with greater diuresis and more favorable outcomes in some secondary measures but also with transient worsening of renal function. CONCLUSIONS: Among patients with acute decompensated heart failure, there were no significant differences in patients' global assessment of symptoms or in the change in renal function when diuretic therapy was administered by bolus as compared with continuous infusion or at a high dose as compared with a low dose. (Funded by the National Heart, Lung, and Blood Institute; ClinicalTrials.gov number, NCT00577135.).

Regulation of circulating progenitor cells in left ventricular dysfunction.

BACKGROUND: Reductions in numbers of circulating progenitor cells (CD34+ cell subsets) have been demonstrated in patients at risk for, or in the presence of, cardiovascular disease. The mediators of these reductions remain undefined. To determine whether neurohumoral factors might regulate circulating CD34+ cell subsets in vivo, we studied complementary canine models of left ventricular (LV) dysfunction. METHODS AND RESULTS: A pacing model of severe LV dysfunction and a hypertensive renal wrap model in which dogs were randomized to receive deoxycorticosterone acetate (DOCA) were studied. Circulating CD34+ cell subsets including hematopoietic precursor cells (HPCs: CD34+/CD45(dim)/VEGFR2-) and endothelial progenitor cells (EPCs: CD34+/CD45-/VEGFR2+) were quantified. Additionally, the effect of mineralocorticoid excess on circulating progenitor cells in normal dogs was studied. The majority of circulating CD34+ cells expressed CD45dimly and did not express VEGFR2, consistent with an HPC phenotype. HPCs were decreased in response to pacing, and this decrease correlated with plasma aldosterone levels (Spearman rank correlation=-0.67, P=0.03). In the hypertensive renal wrap model, administration of DOCA resulted in decreased HPCs. No changes were seen in EPCs in either model. Normal dogs treated with DOCA exhibited a decrease in HPCs in peripheral blood but not bone marrow associated with decreased telomerase activity. CONCLUSIONS: This is the first study to demonstrate that mineralocorticoid excess, either endogenous or exogenous, results in reduction in HPCs. These data suggest that mineralocorticoids may induce accelerated senescence of progenitor cells, leading to their reduced survival and decline in numbers.

Advanced glycation end products accumulate in vascular smooth muscle and modify vascular but not ventricular properties in elderly hypertensive canines.

BACKGROUND: Advanced glycation end products (AGEs) are believed to increase left ventricular (LV) and vascular stiffness, in part via cross-linking proteins. We determined whether and where AGEs were increased in elderly hypertensive nondiabetic dogs and whether an AGE cross-link breaker (ALT-711) improved vascular or ventricular function. METHODS AND RESULTS: Elderly dogs with experimental hypertension (old hypertensives [OH]) were randomized to receive ALT-711 (OH+ALT group; n=11; 1 mg/kg PO) or not (OH group; n=11) for 8 weeks. Conscious blood pressure measurements (weekly), echocardiography (week 8), and anesthetized study (week 8) with LV pressure-volume analysis and aortic pressure-dimension and pressure-flow assessment over a range of preloads and afterloads were performed. In LV and aorta from OH, OH+ALT, and young normal dogs, AGE content (immunohistochemistry and Western analysis for N(epsilon)-(carboxymethyl)lysine [CML]) was assessed. Aortic CML content was markedly increased in OH and OH+ALT dogs compared with young normal dogs. CML was localized to aortic and aortic vasa vasorum smooth muscle but not to collagen or elastin. CML was essentially undetectable in young normal, OH, or OH+ALT myocardium but was visible in large vessels in the LV. ALT-711 therapy was associated with lower blood pressure and pulse pressure, decreased systemic vascular resistance, increased aortic distensibility and arterial compliance, and, notably, significant aortic dilatation. Neither LV systolic nor diastolic function was different in OH+ALT versus OH dogs. CONCLUSIONS: In elderly hypertensive canines, AGE accumulation and AGE cross-link breaker effects were confined to the vasculature without evidence of myocardial accumulation or effects. The lack of AGE accumulation in collagen-rich areas suggests that the striking vascular effects may be mediated by mechanisms other than collagen cross-linking.

The effects of nesiritide on renal function and diuretic responsiveness in acutely decompensated heart failure patients with renal dysfunction.

BACKGROUND: Strategies to preserve renal function and enhance diuretic responsiveness during therapy for heart failure (HF) are needed. We hypothesized that brain natriuretic peptide (nesiritide) added to standard HF therapy would preserve renal function and enhance diuretic responsiveness. METHODS: Patients with HF with underlying renal dysfunction who were admitted with volume overload were randomized to standard therapy with nesiritide (2 mug/kg bolus; 0.01 mug/kg/min for 48 hours) or without nesiritide. Patients requiring intravenous vasodilator or inotropic therapy for rapid symptom relief were ineligible. In all patients, diuretics were administered according to a standardized dosing algorithm. RESULTS: Patients (n = 72) had a mean creatinine level of 1.75 +/- 0.59 mg/dL. Patients receiving nesiritide had a lesser increase in creatinine (P = .048) and blood urea nitrogen (P = .02), but a greater reduction in blood pressure (P < .01). Nesiritide did not enhance diuretic responsiveness (P = .57) but increased 3'5' cyclic guanosine monophosphate and decreased endothelin more (P < .05 for both). There were no differences in the change in atrial natriuretic peptide, N-terminal pro-brain natriuretic peptide, plasma renin activity, angiotensin II, and aldosterone between groups. CONCLUSION: When used as adjuvant "renal protective" therapy in patients with HF with renal dysfunction, the recommended dose of nesiritide reduced blood pressure, did not seem to worsen renal function, and suppressed endothelin but did not enhance diuretic responsiveness or prevent activation of the renin-angiotensin-aldosterone system.

Bioenergetic protection of failing atrial and ventricular myocardium by vasopeptidase inhibitor omapatrilat.

Deficient bioenergetic signaling contributes to myocardial dysfunction and electrical instability in both atrial and ventricular cardiac chambers. Yet, approaches capable to prevent metabolic distress are only partially established. Here, in a canine model of tachycardia-induced congestive heart failure, we compared atrial and ventricular bioenergetics and tested the efficacy of metabolic rescue with the vasopeptidase inhibitor omapatrilat. Despite intrinsic differences in energy metabolism, failing atria and ventricles demonstrated profound bioenergetic deficiency with reduced ATP and creatine phosphate levels and compromised adenylate kinase and creatine kinase catalysis. Depressed phosphotransfer enzyme activities correlated with reduced tissue ATP levels, whereas creatine phosphate inversely related with atrial and ventricular load. Chronic treatment with omapatrilat maintained myocardial ATP, the high-energy currency, and protected adenylate and creatine kinase phosphotransfer capacity. Omapatrilat-induced bioenergetic protection was associated with maintained atrial and ventricular structural integrity, albeit without full recovery of the creatine phosphate pool. Thus therapy with omapatrilat demonstrates the benefit in protecting phosphotransfer enzyme activities and in preventing impairment of atrial and ventricular bioenergetics in heart failure.