The epidemiological enigma of heart failure with preserved systolic function

[Management of heart failure at the CHU the National Reference of Ndjamena/Chad]

INTRODUCTION

Heart failure (HF) is a syndrome of diverse etiologies, and a real public health problem in both developed and developing countries. The aim of this study was to determine the clinical, etiological, therapeutic and evolutionary aspects of heart failure.

MATERIALS AND METHODS

This was a descriptive and analytical study carried out in the cardiology department of the national referral university hospital in N'Djamena (Chad).

RESULTS

Heart failure accounted for 30.84% of cardiovascular pathologies hospitalized in the cardiology department during the study period. The mean age of our patients was 52 ± 34 years, with extremes ranging from 18 to 87 years. Females predominated, accounting for 50.7% of cases, with a M/F sex-ratio of 0.97. Hypertensive heart disease (33.7%), valvular heart disease (16.6%) and ischemic heart disease (15.1%) were the most frequent etiologies. The drugs most frequently used were loop diuretics (97%), ACE inhibitors (96%) and beta-blockers (93.5%). The in-hospital mortality rate was 9% in our series.

Assessing strategies for heart failure with preserved ejection fraction at the outpatient clinic

BACKGROUND

Heart failure with preserved ejection fraction (HFPEF) is the most common form of heart failure (HF), its diagnosis being a challenge to the outpatient clinic practice.

OBJECTIVE

To describe and compare two strategies derived from algorithms of the European Society of Cardiology Diastology Guidelines for the diagnosis of HFPEF.

METHODS

Cross-sectional study with 166 consecutive ambulatory patients (67.9±11.7 years; 72% of women). The strategies to confirm HFPEF were established according to the European Society of Cardiology Diastology Guidelines criteria. In strategy 1 (S1), tissue Doppler echocardiography (TDE) and electrocardiography (ECG) were used; in strategy 2 (S2), B-type natriuretic peptide (BNP) measurement was included.

RESULTS

In S1, patients were divided into groups based on the E/E'ratio as follows: GI, E/E'> 15 (n = 16; 9%); GII, E/E'8 to 15 (n = 79; 48%); and GIII, E/E'< 8 (n = 71; 43%). HFPEF was confirmed in GI and excluded in GIII. In GII, TDE [left atrial volume index (LAVI) ≥ 40 mL/m2; left ventricular mass index LVMI) > 122 for women and > 149 g/m2 for men] and ECG (atrial fibrillation) parameters were assessed, confirming HFPEF in 33 more patients, adding up to 49 (29%). In S2, patients were divided into three groups based on BNP levels. GI (BNP > 200 pg/mL) consisted of 12 patients, HFPEF being confirmed in all of them. GII (BNP ranging from 100 to 200 pg/mL) consisted of 20 patients with LAVI > 29 mL/m2, or LVMI ≥ 96 g/m2 for women or ≥ 116 g/m2 for men, or E/E'≥ 8 or atrial fibrillation on ECG, and the diagnosis of HFPEF was confirmed in 15. GIII (BNP < 100 pg/mL) consisted of 134 patients, 26 of whom had the diagnosis of HFPEF confirmed when GII parameters were used. Measuring BNP levels in S2 identified 4 more patients (8%) with HFPEF as compared with those identified in S1.

CONCLUSION

The association of BNP measurement and TDE data is better than the isolated use of those parameters. BNP can be useful in identifying patients whose diagnosis of HF had been previously excluded based only on TDE findings.

Role of estrogen in diastolic dysfunction

The prevalence of left ventricular diastolic dysfunction (LVDD) sharply increases in women after menopause and may lead to heart failure. While evidence suggests that estrogens protect the premenopausal heart from hypertension and ventricular remodeling, the specific mechanisms involved remain elusive. Moreover, whether there is a protective role of estrogens against cardiovascular disease, and specifically LVDD, continues to be controversial. Clinical and basic science have implicated activation of the renin-angiotensin-aldosterone system (RAAS), linked to the loss of ovarian estrogens, in the pathogenesis of postmenopausal diastolic dysfunction. As a consequence of increased tissue ANG II and low estrogen, a maladaptive nitric oxide synthase (NOS) system produces ROS that contribute to female sex-specific hypertensive heart disease. Recent insights from rodent models that mimic the cardiac phenotype of an estrogen-insufficient or -deficient woman (e.g., premature ovarian failure or postmenopausal), including the ovariectomized congenic mRen2.Lewis female rat, provide evidence showing that estrogen modulates the tissue RAAS and NOS system and related intracellular signaling pathways, in part via the membrane G protein-coupled receptor 30 (GPR30; also called G protein-coupled estrogen receptor 1). Complementing the cardiovascular research in this field, the echocardiographic correlates of LVDD as well as inherent limitations to its use in preclinical rodent studies will be briefly presented. Understanding the roles of estrogen and GPR30, their interactions with the local RAAS and NOS system, and the relationship of each of these to LVDD is necessary to identify new therapeutic targets and alternative treatments for diastolic heart failure that achieve the cardiovascular benefits of estrogen replacement without its side effects and contraindications.

Diastolic dysfunction and heart failure with a preserved ejection fraction: Relevance in critical illness and anaesthesia

Epidemiological and clinical studies suggest that HF with a preserved ejection fraction will become the more common form of HF which clinicians will encounter. The spectrum of diastolic disease extends from the asymptomatic phase to fulminant cardiac failure. These patients are commonly encountered in operating rooms and critical care units. A clearer understanding of the underlying pathophysiology and clinical implications of HF with a preserved ejection fraction is fundamental to directing further research and to evaluate interventions. This review highlights the impact of diastolic dysfunction and HF with a preserved ejection fraction during the perioperative period and during critical illness.

The natural history of preclinical diastolic dysfunction: a population-based study

BACKGROUND

Preclinical diastolic dysfunction (PDD) has been broadly defined as subjects with left ventricular diastolic dysfunction, without the diagnosis of congestive heart failure (HF) and with normal systolic function. Our objective was to determine the risk factors associated with the progression from PDD (stage B) HF to symptomatic (stage C) HF.

METHODS AND RESULTS

Using the resources of the Rochester Epidemiology Project, all residents of Olmsted County, MN, who underwent echocardiography between January 1, 2004, and December 31, 2005, and had grade 2-4 diastolic dysfunction and ejection fraction ≥50% were identified. Patients with a diagnosis of HF before or within 30 days of the echocardiogram were excluded. Patients were also excluded if they had a diagnosis of atrial fibrillation or severe mitral or aortic valve regurgitation at the time of the echocardiogram. A total of 388 patients met the inclusion criteria. The mean age of the cohort was 67±12 years, with a female (57%) predominance. Prevalence of renal insufficiency (estimated glomerular filtration rate <60 mL/min per 1.73 m(2)) was 34%. The 3-year cumulative probabilities of development of (stage C) HF, development of atrial fibrillation, cardiac hospitalization, and mortality were 11.6%, 14.5%, 17.7%, and 10.1% respectively. In multivariable Cox proportional hazard regression analysis, we determined that age, renal dysfunction, and right ventricular systolic pressure were independently associated with the development of HF.

CONCLUSIONS

This population-based study demonstrated that in PDD (stage B) HF, there was a moderate degree of progression to symptomatic (stage C) HF over 3 years, and renal dysfunction was associated with this progression independent of age, sex, hypertension, coronary disease, and ejection fraction.

Nuclear cardiology and heart failure

The prevalence of heart failure in the adult population is increasing. It varies between 1% and 2%, although it mainly affects elderly people (6-10% of people over the age of 65 years will develop heart failure). The syndrome of heart failure arises as a consequence of an abnormality in cardiac structure, function, rhythm, or conduction. Coronary artery disease is the leading cause of heart failure and it accounts for this disorder in 60-70% of all patients affected. Nuclear techniques provide unique information on left ventricular function and perfusion by gated-single photon emission tomography (SPECT). Myocardial viability can be assessed by both SPECT and PET imaging. Finally, autonomic dysfunction has been shown to increase the risk of death in patients with heart disease and this may be applicable to all patients with cardiac disease regardless of aetiology. MIBG scanning has a very promising prognostic value in patients with heart failure.

Initial emergency department systolic blood pressure predicts left ventricular systolic function in acute decompensated heart failure

Ejection fraction (EF) is often unknown in patients who present with acute decompensated heart failure (ADHF). The objective of this study was to determine whether a patient's systolic blood pressure is associated with their left ventricular EF. This study was a retrospective chart review of all patients admitted to an emergency department (ED) observation unit from January 2002 to December 2004. A low EF was defined as <40%. Among 475 patients, the median age was 72 years, 53% were men, 40% were white, 59% were black, and 59% had a low EF. Patients with low EFs were more likely male ( P<.0001), with prior congestive heart disease ( P<.0001), longer QRS duration ( P<.0001), left bundle branch block ( P<.0001), and higher B-type natriuretic peptide ( P<.0001). The low EF group was less likely to have diabetes ( P<.0001). Adjusted odds ratios for an EF >or=40% were significant at all systolic blood pressure readings >120 mm Hg. Having an ED systolic BP >120 mm Hg is associated with significantly higher rates of preserved left ventricular systolic function in patients with ADHF.

Ejection fraction and blood pressure are important and interactive predictors of 4-week mortality in severe acute heart failure

BACKGROUND

In acute heart failure syndromes (AHFS), the prognostic value of left ventricular ejection fraction (LVEF), although widely accepted, has been recently challenged. In contrast, blood pressure is increasingly gaining ground over LVEF as predictor of mortality. Therefore, it is not clear whether both LVEF and mean arterial pressure (MAP) are independent risk factors in patients with AHFS.

METHODS AND RESULTS

The EFICA study enrolled 581 AHFS patients admitted to 60 CCU/ICUs. Survival at 4 weeks was analyzed for all cases with echocardiographic LVEF available on admission (n=355). Four-week mortality was 23%. Multivariable analysis identified lower LVEF, lower MAP and serum creatinine >1.5 mg/dl as independent correlates of mortality (respectively, OR: 1.27 per 10% decrease, CI: 1.05-1.53, p=0.012; OR: 1.30 per 10 mmHg decrease, CI: 1.15-1.48, p<0.0001; OR: 2.84, CI: 1.64-4.93, p=0.0002). LVEF interacted significantly with MAP (p<0.0001) and the subgroup analysis showed that reduced LVEF was a strong risk factor in patients with MAP <or=90 mmHg (OR: 2.73, CI: 1.23-5.98, p=0.01) but did not reach statistical significance in patients with MAP >90 mmHg.

CONCLUSIONS

Both LVEF and MAP are important predictors of death in severe AHFS. LVEF can provide additional prognostic information on top of MAP but mainly in patients with low MAP (<or=90 mmHg) at admission.

Systolic and diastolic heart failure: Different phenotypes of the same disease?

Traditional pathophysiological concepts of chronic heart failure have largely focused on the haemodynamic consequences of ventricular systolic dysfunction. How these concepts relate to the pathophysiology of diastolic heart failure, i.e., heart failure with a preserved ejection fraction is, however, unclear, causing uncertainty about pathophysiology, diagnosis and management. Recent measurements of regional myocardial systolic function in patients with diastolic heart failure indicate that systolic and diastolic heart failure may be more closely related than previously anticipated. Rather than being considered as separate diseases with a distinct pathophysiology, systolic and diastolic heart failure may be merely different clinical presentations within a phenotypic spectrum of one and the same disease. In this review, we will interpret these new insights in a broader conceptual context of chronic heart failure and design novel paradigms in which systolic and diastolic heart failure jointly progress in a pathophysiological time trajectory of only one disease.

Diastolic Heart Failure: Perception of the Syndrome and Scope of the Problem

Diastolic Heart Failure: perception of the syndrome and scope of the problem. As a result of the recent publications of the CHARM-Preserved trial, the upcoming I-PRESERVE and other still ongoing clinical trials in patients with Heart Failure and Normal (or Preserved) Left Ventricular Ejection Fraction, numerous questions have arisen as for the conceptual rationale and pathophysiological basis of such trials. The present symposium is a synopsis of the most important remaining controversies. We gratefully acknowledge all authors for their contribution as summarized in this Introduction Paper.

Diastolic dysfunction and diastolic heart failure: mechanisms and epidemiology

Studies have demonstrated that diastolic dysfunction is frequently present in asymptomatic community-based individuals, especially in the elderly with hypertension, coronary artery disease, and diabetes. The presence of diastolic dysfunction is a predictor for the development of heart failure (HF) and confers a higher risk of mortality. These findings have raised the question of whether treating preclinical diastolic dysfunction will be helpful in preventing or delaying the onset of clinical HF and mortality, as has been proven with treatment of asymptomatic left ventricular systolic dysfunction. In addition, in some individuals, diastolic dysfunction in the presence of a normal ejection fraction is associated with exercise intolerance as well as symptomatic clinical HF, referred to as diastolic HF. Patients with diastolic HF, who are more often elderly women, have a significant mortality and morbidity burden compared with age-matched controls. Studies that further our understanding of mechanisms underlying diastolic dysfunction and diastolic HF will provide potential new targets for development of effective therapies for these conditions.

Diastolic heart failure: a myth

PURPOSE OF REVIEW

Until recently, patients with heart failure and preserved ejection fraction (HFprEF) have been excluded from nearly all large clinical trials in heart failure. Based on the conjecture that this clinical picture of heart failure, also known as diastolic heart failure, may be different from other forms of heart failure, several recent and ongoing clinical trials have targeted more specifically this patient population. The present review critically re-evaluates the pathophysiological rationale for such trials.

RECENT FINDINGS

Novel techniques to evaluate cardiac performance have revealed that HFprEF is a consequence of significant systolic dysfunction of the ventricular muscular pump in the presence of a preserved performance of the ventricular hemodynamic pump. Diastolic and systolic heart failure are the mere extremes of a spectrum of different phenotypes of one and the same disease. Ongoing research explores the various disease modifiers, or protective pathways, that delay the progression of remodeling in patients with HFprEF. Although, currently, therapy to improve the prognosis of HFprEF is essentially the same as for other forms of heart failure, the latter ongoing studies may help, in addition, in developing novel and more patient-specific therapeutic strategies in these patients.

SUMMARY

HFprEF constitutes a heterogenous group of different phenotypes within one continuous spectrum reflecting heart failure as one disease entity. No pathophysiological basis currently warrants setting up empirical clinical trials based on an arbitrary subdivision of patients with heart failure.

The Irbesartan in Heart Failure With Preserved Systolic Function (I-PRESERVE) Trial: Rationale and Design

BACKGROUND

Although 40% to 50% of patients with chronic heart failure (HF) have relatively preserved systolic function (PSF), few trials have been conducted in this population and treatment guidelines do not include evidence-based recommendations.

METHODS AND RESULTS

The Irbesartan in Heart Failure with Preserved Systolic Function (I-PRESERVE) is enrolling 4100 subjects with HF-PSF to evaluate whether 300 mg irbesartan is superior to placebo in reducing mortality and prespecified categories of cardiovascular hospitalizations. The principal inclusion criteria are age > or =60 years, heart failure symptoms, an ejection fraction > or =45%, and either hospitalization for heart failure within 6 months or corroborative evidence of heart failure or the substrate for diastolic heart failure. Additional secondary end points include cardiovascular mortality, cause-specific mortality and morbidity, change in New York Heart Association functional class, quality of life, and N-terminal pro-BNP measurements. Follow-up will continue until 1440 patients experience a primary end point. Substudies will evaluate changes in echocardiographic measurements and serum collagen markers.

CONCLUSION

I-PRESERVE is the largest trial in this understudied area and will provide crucial information on the characteristics and course of the syndrome, as well as the efficacy of the angiotensin receptor blocker irbesartan.

Different prognostic impact of systolic function in patients with heart failure and/or acute myocardial infarction

AIMS

To study the prognostic importance of left ventricular systolic function in patients with heart failure (HF) and acute myocardial infarction (AMI) with respect to the presence of prior heart failure and known ischemic heart disease.

METHODS

In 13,084 consecutive patients diagnosed with either AMI or HF, a medical history and an echocardiographic assessment of left ventricular systolic function by wall motion index (WMI) were obtained. Patients were divided into four groups: AMI with or without a history of HF, and primary HF (no recent AMI) with or without a history of ischemic heart disease (IHD). Mortality was assessed after nine years of follow-up.

RESULTS

WMI stratified patients according to all-cause mortality in all four groups of patients (p<0.0001). For a decrease in WMI of 0.3 (corresponding to a decrease in left ventricular ejection fraction of 0.1), the hazard ratio was 1.61 (95% CI: 1.48-1.76) for AMI patients without prior HF, 1.43 (1.38-1.48) for AMI patients with prior HF, 1.26 (1.22-1.30) for primary HF patients with IHD and 1.23 (1.18-1.27) for HF patients without IHD.

CONCLUSION

WMI stratifies patients with IHD and/or HF according to risk of all-cause death. The presence of HF attenuates the prognostic power of WMI.