Is heart failure with decent systole due to bad diastole?

Heart failure with preserved ejection fraction: an ongoing enigma

Heart failure with preserved ejection fraction (HFpEF) is a complex clinical syndrome based on traditional heart failure symptoms with documentation of increased left ventricular filling pressures and preserved left ventricular ejection fraction. The exact mechanisms that induce HFpEF are not known. End-diastolic ventricular stiffness does not seem to be acting alone. Substantial mortality exists compared with healthy age-matched controls, as well as significant health care expenditures on hospitalizations and readmissions. This article reviews the epidemiology, pathophysiology, and treatment of heart failure with preserved ejection fraction (HFpEF). Current practice guidelines focus on remedying volume overload, aggressively controlling hypertension, and treatment of comorbid conditions that contribute to decompensation.

Treatment of heart failure with preserved ejection fraction: have we been pursuing the wrong paradigm?

Heart failure with preserved ejection fraction (HF-PEF) is the clinical syndrome of heart failure associated with normal or near-normal systolic function. Because inhibition of the adrenergic and renin-angiotensin-aldosterone systems has been so effective in the treatment of systolic heart failure, these same therapies have been the subject of recent clinical trials of HF-PEF. In this review, we examine the current evidence about treatment of HF-PEF, with particular emphasis on reviewing the literature for large-scale randomized clinical studies. The lack of significant benefit with neurohormonal antagonism in HF-PEF suggests that this condition might not involve neurohormonal activation as a critical pathophysiologic mechanism. Perhaps heart failure as we traditionally think of it is the wrong paradigm to pursue as we try to understand this condition of volume overload known as HF-PEF.

Death in heart failure: a community perspective

BACKGROUND

Mortality in heart failure (HF) remains high but causes of death are incompletely defined. As HF is heterogeneous syndrome categorized according to ejection fraction (EF), the association between EF and causes of death is important, yet elusive.

METHOD AND RESULTS

Community subjects with HF were classified according to preserved (> or =50%) and reduced EF (<50%). Deaths were classified as coronary heart disease (CHD), other cardiovascular and non-cardiovascular. Among 1063 persons with HF, 45% had preserved EF with less cardiovascular risk factors and less coronary disease than those with reduced EF. At 5 years, survival was 45% (95% CI 43%-49%) and 43% of the deaths were non-cardiovascular. The leading cause of death in subjects with preserved EF was non-cardiovascular (49%) vs CHD (43%) for subjects with reduced EF. The proportion of cardiovascular deaths decreased from 69% in 1979-1984 to 40% in 1997-2002 (p=0.007) among subjects with preserved EF contrasting with a modest change among those with reduced EF (77% in to 64%, p=0.08). Advanced age, male sex, diabetes, smoking and kidney disease were associated with an increase risk of all cause and cardiovascular death. After adjustment, preserved EF was associated with a lower risk of cardiovascular death but not all cause death.

CONCLUSION

Community subjects with HF experience a persistently high mortality and a large proportion of deaths are non-cardiovascular. Subjects with preserved EF have less cardiovascular disease before death, are less likely to experience cardiovascular deaths than those with reduced EF and the proportion of cardiovascular deaths declined over time.

Differences in arterial compliance, microvascular function and venous capacitance between patients with heart failure and either preserved or reduced left ventricular systolic function

BACKGROUND

Up to 50% of patients with the clinical syndrome of heart failure have preserved left ventricular systolic function (HF-PSF). These patients may have abnormalities of ventriculo-vascular coupling, due to increased vascular and ventricular stiffness.

METHODS

We compared arterial compliance, microvascular vasodilator function and venous capacitance (VC) in 3 groups of patients (n=12 each) matched for the presence of coronary heart disease: 1) HF and preserved systolic function (HF-PSF), 2) HF and reduced systolic function (HF-RSF) and 3) controls (no HF, PSF). Arterial compliance was assessed by measuring aortic pulse wave velocity (PWV) with applanation tonometry. Cutaneous microvascular function was assessed using Laser Doppler imaging (LDI) coupled with iontophoresis of endothelium-dependent (acetylcholine) and -independent (sodium nitroprusside) vasodilators. VC was measured using venous occlusion plethysmography.

RESULTS

PWV was significantly higher in HF-PSF subjects than in both HF-RSF and control groups (10.7 [1.1], 8.9 [1.7] and 8.6 [2.1] m/s respectively, p<0.05). Acetylcholine and nitroprusside induced vasodilatation were equally impaired in HF-PSF and HF-RSF, as compared to controls (p<0.01). VC was higher in HF-RSF subjects compared with HF-PSF subjects (1.75 [0.41], 1.34 [0.34] ml/100 ml forearm vol. respectively, p<0.05).

CONCLUSIONS

These findings are consistent with a more marked increase in vascular stiffness in HF-PSF than in HF-RSF and suggest that arterial stiffness, dynamic vasodilator function and venous abnormalities may be implicated in the complex pathophysiology of HF-PSF.

A phase 1-2 dose-escalating study evaluating the safety and tolerability of istaroxime and specific effects on electrocardiographic and hemodynamic parameters in patients with chronic heart failure with reduced systolic function

Istaroxime (PST2744) is a luso-inotrope that stimulates the sarcoplasmic reticulum calcium adenosine triphosphatase isoform 2a without chronotropic effects. Additionally, it has beneficial effects on myocardial energetics. This phase 1-2 clinical trial in patients with chronic stable heart failure (HF) is the first evaluation of istaroxime in humans. Three cohorts of 6 patients each were exposed to 4 sequentially increasing 1-hour infusions with a random placebo. Doses were 0.005-5.0 micro/kg per min. Safety and hemodynamics were evaluated by impedance cardiography, digital Holter recorder, and electrocardiography. Pharmacokinetic data were obtained for 1 hour during treatment and for 6 hours after dosing. The mean age was 53+/-7 years, and the mean left ventricular ejection fraction was 0.27+/-0.08. Impedance cardiography demonstrated enhanced contractility as measured by the acceleration index, left cardiac work index, cardiac index, and pulse pressure at doses>or=1 micro/kg per min, with evidence of activity at doses of 0.5 micro/kg per min. Istaroxime shortened QTc. After infusion, the hemodynamic effect rapidly dissipated over 1-2 hours. Istaroxime was pharmacologically active and well tolerated at doses up to 3.33 micro/kg per min. Side effects were related to gastrointestinal symptoms and injection site pain at higher doses, which dissipated within minutes after the infusion ended. Ventricular ectopy was not altered. This study suggests that istaroxime is potentially useful in the treatment of HF and may offer a unique treatment for systolic and/or diastolic dysfunction. Additional studies are under way to further define its utility in acute HF.