Sheryl L. Chow

Introduction: This review summarizes the current management of heart failure (HF) in patients with reduced ejection fraction and the potential role of heart rate lowering agents in select populations, as recommended in the updated guidelines. Areas covered: PubMed was searched for studies that evaluated the role of heart rate lowering or ivabradine in HF management. Expert commentary: Targeting heart rate may offer benefit when added to renin-angiotensin aldosterone antagonists, and beta-blockers. Ivabradine is a heart rate lowering agent that acts on the funny current (I_f) in the sinoatrial node, thereby reducing heart rate without directly affecting cardiac contraction and relaxation. Clinical data from a phase III trial demonstrated that ivabradine reduced the composite end point of cardiovascular death or hospital admission for worsening systolic HF, while maintaining an acceptable safety profile in patients receiving standard of care therapy. These data, in addition to more recently published guidelines, suggest ivabradine as a promising new treatment option for lowering heart rate after optimizing standard therapy in select patients with chronic HF.

Nesiritide, a recombinant form of B-type natriuretic peptide, is a vasodilator and currently recommended as an additive therapy for patients with acute decompensated heart failure (ADHF) who have been optimized on loop diuretics. With hospitalizations for ADHF rising, appropriate selection of therapy becomes even more important to optimize efficacy and reduce adverse events. Nesiritide has many properties that antagonize the pathophysiologic processes of heart failure and has demonstrated a comparative benefit in previous reports; however, controversy still remains with respect to its efficacy and safety. Based on results from recent clinical trials, nesiritide has been shown to be safe at currently approved doses and strongly considered for the treatment of ADHF in patients who remain symptomatic despite optimal doses of intravenous loop divertics.

Heart failure ( HF ) care takes place in multiple settings, with a variety of providers, and generally involves patients who have multiple comorbidities. This situation is a “perfect storm” of factors that predispose patients to medication errors. The goals of this paper are to outline potential roles for clinical pharmacists in a multidisciplinary HF team, to document outcomes associated with interventions by clinical pharmacists, to recommend minimum training for clinical pharmacists engaged in HF care, and to suggest financial strategies to support clinical pharmacy services within a multidisciplinary team. As patients transition from inpatient to outpatient settings and between multiple caregivers, pharmacists can positively affect medication reconciliation and education, assure consistency in management that results in improvements in patient satisfaction and medication adherence, and reduce medication errors. For mechanical circulatory support and heart transplant teams, the Centers for Medicare and Medicaid Services considers the participation of a transplant pharmacology expert (e.g., clinical pharmacist) to be a requirement for accreditation, given the highly specialized and complex drug regimens used. Although reports of outcomes from pharmacist interventions have been mixed owing to differences in study design, benefits such as increased use of evidence‐based therapies, decreases in HF hospitalizations and emergency department visits, and decreases in all‐cause readmissions have been demonstrated. Clinical pharmacists participating in HF or heart transplant teams should have completed specialized postdoctoral training in the form of residencies and/or fellowships in cardiovascular and/or transplant pharmacotherapy, and board certification is recommended. Financial mechanisms to support pharmacist participation in the HF teams are variable. Positive outcomes associated with clinical pharmacist activities support the value of making this resource available to HF teams.

Despite numerous pharmacologic and nonpharmacologic treatment strategies, heart failure remains a complex, progressive disorder with significant morbidity and mortality. Angiotensin‐converting enzyme (ACE) inhibitors, angiotensin II receptor blockers (ARBs), and β‐blockers have been used as routine treatment options for heart failure for the majority of patients with left ventricular systolic dysfunction who tolerate these agents. Mineralocorticoid receptor antagonists (MRAs) have also demonstrated significant benefits in the treatment of heart failure, which include a reduction in sudden cardiac death and ventricular remodeling; however, these agents have not been recommended for most patients with heart failure. In the most recent American College of Cardiology Foundation and American Heart Association guidelines, MRAs are recommended for patients with New York Heart Association class III or IV symptoms or previous acute myocardial infarction, provided an absence of contraindications or risk factors for developing hyperkalemia. Based on more recent evidence, it is likely that future recommendations and guidelines will further expand the use of MRAs to patients with mild heart failure as well. These agents have the potential to be recommended nearly as universally as ACE inhibitors and β‐blockers because of the potential to reduce mortality and hospital admissions for heart failure. The risk of hyperkalemia should be carefully assessed when using these drugs; nonetheless, new strategies being developed may reduce the occurrence of hyperkalemia as well.

Background: Previous studies have shown that long-term oral daily PDE 5 inhibitors (PDE5i) counteract fibrosis, cell loss, and the resulting dysfunction in tissues of various rat organs and that implantation of skeletal muscle-derived stem cells (MDSC) exerts some of these effects. PDE5i and stem cells in combination were found to be more effective in non-MI cardiac repair than each treatment separately. We have now investigated whether sildenafil at lower doses and MDSC, alone or in combination are effective to attenuate LV remodeling after MI in rats.Methods: MI was induced in rats by ligature of the left anterior descending coronary artery. Treatment groups were: “Series A”: 1) untreated; 2) oral sildenafil 3 mg/kg/day from day 1; and “Series B”: intracardiac injection at day 7 of: 3) saline; 4) rat MDSC (10⁶cells); 5) as #4, with sildenafil as in #2. Before surgery, and at 1 and 4 weeks, the left ventricle ejection fraction(LVEF)was measured. LV sections were stained for collagen,myofibroblasts, apoptosis, cardiomyocytes, and iNOS, followed by quantitative image analysis.Western blots estimated angiogenesis and myofibroblast accumulation, as well as potential sildenafil tachyphylaxis by PDE 5 expression. Zymography estimated MMPs 2 and 9 in serum.Results: As compared to untreated MI rats, sildenafil improved LVEF, reduced collagen, myofibroblasts, and circulating MMPs, and increased cardiac troponin T. MDSC replicated most of these effects and stimulated cardiac angiogenesis. Concurrent MDSC/sildenafil counteracted cardiomyocyte and endothelial cells loss, but did not improve LVEF or angiogenesis, and upregulated PDE 5.Conclusions: Long-term oral sildenafil, or MDSC given separately, reduce the MI fibrotic scar and improve left ventricular function in this rat model. The failure of the treatment combination may be due to inducing overexpression of PDE5.