Heart failure with preserved ejection fraction and systolic dysfunction in the community

Abstracts

FUNDAMENTO: Em países desenvolvidos, a insuficiência cardíaca com fração de ejeção preservada (ICFEP) é o modelo mais prevalente que a insuficiência cardíaca com disfunção sistólica (ICDS) na comunidade. No entanto, não está plenamente estabelecido se tal fato também é observado na nossa comunidade. OBJETIVO: Determinar o tipo mais prevalente de insuficiência cardíaca (ICFEP ou ICDS) e se a prevalência de ICFEP é elevada na comunidade. MÉTODOS: Estudo transversal de pacientes atendidos na comunidade com diagnóstico clínico de IC, de janeiro a dezembro de 2005. O ecodopplercardiograma foi realizado em todos os pacientes. O tipo de IC foi estratificado pela presença de anormalidades e pela fração de encurtamento ao ecodopplercardiograma. RESULTADOS: O estudo avaliou 170 pacientes (61,0±13,3 anos), a maioria mulheres e idosos. A ICFEP foi o tipo de IC mais prevalente (64,2%, p<0,001) com tendência nas mulheres idosas (62%, p=0,07), e o inverso na ICDS, nos homens idosos (63,6%, p=0,07). Os pacientes sem IC representaram um terço dos casos (27,6%). A ICDS apresentou mais edema de membros inferiores, doença coronariana, diabete, insuficiência renal crônica, re-internações e maior escore de Boston. O etilismo e o tabagismo estiveram mais presentes na ICDS. CONCLUSÃO: A ICFEP é o tipo de IC mais prevalente na comunidade, principalmente nas mulheres idosas, enquanto a ICDS, nos homens idosos, com maior gravidade clínica e acometimento dos principais fatores de risco e sem modificação nos hábitos de vida. Apesar dos sinais e dos sintomas de IC, em um terço dos casos a IC não foi confirmada.

Insuficiência cardíaca; função ventricular; volume sistólico

ORIGINAL ARTICLE

Heart failure with preserved ejection fraction and systolic dysfunction in the community

Marco Aurélio Esposito Moutinho; Flávio Augusto Colucci; Veronica Alcoforado; Leandro Reis Tavares; Mauricio Bastos Freitas Rachid; Maria Luisa Garcia Rosa; Mário Luiz Ribeiro; Rosemery Abdalah; Juliana Lago Garcia; Evandro Tinoco Mesquita

Universidade Federal Fluminense, Fundação Municipal de Saúde de Niterói - Programa Médico de Família, Niterói, RJ - Brazil

Mailing Address

SUMMARY

BACKGROUND: In developed countries, heart failure with preserved ejection fraction (HFpEF) is more prevalent than heart failure with reduced ejection fraction (HFrEF) in the community. However, it has not been completely established if this fact is also observed within our community.

OBJECTIVE: To determine the most prevalent form of heart failure (HFpEF or HFrEF) and whether the prevalence of HFpEF is higher in the community.

METHODS: This is a cross-sectional study conducted with patients clinically diagnosed with HF who were seen in community-based health care centers from January to December 2005. Echodopplercardiograms were performed for all patients. The form of HF was stratified according to the presence of abnormalities and the shortening fraction observed on the echodopplercardiogram.

RESULTS: The study evaluated 170 patients (61.0 ± 13.3 years of age), most of them women and elderly. HFpEF was the more prevalent form of HF (64.2%, p<0.001), affecting mostly elderly women (62%, p = 0.07), whereas the opposite condition, HFrEF, was observed mostly in elderly men (63.6%, p = 0.07). Patients with no HF represented one-third of the cases (27.6%). HFrEF patients had more lower-limb edema, coronary disease, diabetes, chronic renal failure, higher Boston scores and hospital readmissions. Use of alcoholic beverages and smoking were also more common among HFrEF patients.

CONCLUSION: HFpEF is the most prevalent form of HF in the community especially among elderly women, whereas HFrEF affects mostly elderly men and is associated with greater clinical severity, main risk factors and no changes in lifestyle. Despite the signs and symptoms of HF, this condition was not confirmed for one-third of the cases. (Arq Bras Cardiol 2008; 90(2):132-137)

Key words: Heart failure/epidemiology; ventricular function; stroke volume.

Introduction

Heart failure (HF) is a complex clinical syndrome with several etiologies and a high prevalence^1-6. It is a growing concern among different public health systems due to its high economic impact, particularly in terms of hospitalization costs^7,8.

The known physiopathologic models are heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF). Physiopathology associated with systolic dysfunction has been well studied, and the clinical assays and guidelines set by different medical associations address this specific group of patients^9-12. From a clinical point of view, HF evolves in many different ways – different phenotypes – according to a complexity of interactions with factors modifying the syndrome that are inherent to each individual¹³.

Epidemiological studies in the community show that HFpEF accounts for most cases^2,6,14-17. Although HFpEF has been considered a disease of lesser severity, current data show the clinical importance of the condition by the 5-8% increase in annual mortality rates (compared to 10 to 15% in HFrEF)¹⁸.

In Brazil, HF is an emerging epidemic cardiovascular disease and the third leading cause among all-causes, and the first cause among cardiovascular diseases, for hospitalization in the Unified Health System (SUS) for patients above 65 years of age, raising costs with hospitalization and medication^19,20.

In Niterói, family physicians (FP) provide primary health care^21,22. It is well known that FPs have a limited capacity of perceiving and distinguishing between HFpEF and HFrEF^23,24. Brazilian medical literature lacks epidemiological studies conducted in the community about the prevalence of HFpEF and its associations with risk factors and comorbidities.

The objective of this study is to estimate the prevalence of HF forms (HFrEF and HFpEF) among community patients who have been clinically diagnosed with HF and who were seen by FPs, as well as to identify the clinical characteristics of each form of HF. The central hypothesis is that the rate of HFpEF is high in the community.

Methods

This is an observational cross-section study of patients with a clinical suspicion of HF enrolled in the Programa Médico de Família (Family Physician Program) in the municipality of Niterói. These patients were referred to the specialized outpatient center from January 3 through December 19, 2005.

During the first visit to the outpatient unit, a structured questionnaire was used to obtain the patient’s clinical history with demographic variables, lifestyle, physical examination, anthropometric data, as well as quantification of functional class according to the New York Heart Association (NYHA) criteria. HF was categorized using Boston scores. Blood samples were collected to perform laboratory tests, and patients underwent electrocardiograms, chest X-rays and echodopplercardiograms.

Inclusion criteria were the presence of symptoms and/or signs of HF (dyspnea and/or fatigue and/or lower-limb edema), electrocardiographic abnormalities and/or chest X-ray associated with Boston scores > 5 or therapy with HF medication (diuretics, as a monotherapy and/or combined with ACE-I and/or digitalis).

The variables analyzed on the echodopplercardiogram were: 1) LV shortening fraction < 28%; 2) significant segment abnormality with LV dilation; 3) LV mass index > 134 g/m² in men and > 110 g/m² in women; 4) interventricular septum and LV posterior wall hypertrophy; 5) enlargement of LA diameter². The Devereux formula was used to quantify the mass index, and the Henry formula to quantify interventricular septum and LV posterior wall hypertrophy, as well as LA diameter according to age, gender and body surface^25-27.

Patients were classified according to the structural and functional abnormalities detected on the echodopplercardiogram in the following forms of HF: 1) HFrEF: shortening fraction < 28% or presence of significant segment abnormality with LV dilation; 2) HFpEF: shortening fraction > 28% with no segment abnormality and LV dilation, or increase in the rate of LV mass, or interventricular septum and LF posterior wall hypertrophy when there was no mass rate; 3) absence of HF (AHF): non-identification of morphological and functional abnormalities.

With the objective of verifying if there was a significant relationship between the clinical variables and HF, the following methods were applied:

1) to compare ratios (qualitative variables), the prevalence odds ratio was calculated using the chi-square test (c²) or Fisher’s exact test, according to the number of cases; and

2) To compare age (in years) between two categories, Student’s t-test was used for independent samples; and to compare three categories, the one-way analysis of variance was used.

The statistical analysis was performed with SAS v.6.04 software.

A 5% level was the criterion applied to determine significance.

The study was approved by the Institutional Review Board of the University’s Medical School, and all participants provided written informed consent.

Results

A total of 239 patients with a clinical suspicion of HF enrolled in the Family Physician Program. One-hundred-seventy patients were selected who completed the evaluation performed through the echodopplercardiogram at the university hospital. The mean age was 61 ± 13.3 years, 58% of patients were women, 54% were elderly (> 60 years), 84% had systemic arterial hypertension (SAH), 25% had diabetes mellitus (DM) and 21% had coronary artery disease (CAD).

The echodopplercardiogram showed structural abnormalities in 123 patients, of which 79 (64.2%) had HFpEF, the most prevalent physiopathologic model of HF. Table 1 displays differences between AHF, HFpEF and HFrEF. Indicators of severity, according to NYHA III/IV functional classes, were at least one hospitalization in the preceding year and Boston scores > 5. From a demographic point of view, there were no significant differences among the forms of HF, despite the higher percentage of HFpEF cases among women in comparison with HFrEF. As to signs and symptoms, edema was the sign that most discriminated HF patients (HFpEF and HFrEF), with a higher odds ratio (OR) for those with HFrEF. As to risk factors and comorbidities, the differences were statistically significant only for the presence of CAD, DM and chronic renal failure (CRF) in HFrEF. As to the indicators of severity, there was a greater chance of their being present in HFrEF than in AHF, which did not happen in HFpEF cases except when Boston scores > 5.

Considering just the two physiopathologic models of HF as displayed on Table 2, no statistically significant difference was observed between demographic and lifestyle variables. However, it is worthy mentioning that the chance of an alcoholic beverage drinker developing HFrEF was three times that of his developing HFpEF, whereas the chance of a smoker developing HFpEF was 1.77-fold. Similarly, no statistically significant differences were observed as to signs and symptoms between the two forms of HF, and there was a tendency towards a greater chance of edema in HFrEF. Considering risk factors and comorbidities, the chances of patients with HFrEF developing CAD and CRF were significantly greater (OR 2.40 and 4.79, respectively). The chance of these conditions being more severe was also greater among HFrEF patients, with an OR of 2.9 for hospitalization and 2.35 for Boston scores > 5.

In comparing HFpEF and HFrEF, a tendency was observed toward a higher percentage of HFpEF among elderly women (26 patients, 62% versus 8 patients, 36% p = 0.07), whereas HFrEF was more common among elderly men (14 patients, 63.6% versus 16 patients, 38.1% p = 0.07). The analysis of non-elderly patients (< 60 years) showed that the presence of CAD (10 patients, 45% versus 22 patients, 8% p = 0.05) and DM (11 patients, 50% versus 6 patients, 16% p = 0.007) was more common in HFrEF. In the analysis of elderly patients, hospitalization (7 patients, 32% versus 4 patients, 9% p = 0.03) and Boston scores > 5 (17 patients, 77% versus 20 patients, 48% p = 0.02) were more common in HFrEF.

Discussion

In this cross-sectional study conducted with patients suspected of having HF at the primary evaluation, most of them were identified as having HFpEF and more than half were women and elderly. This was the first study to identify this fact in Brazil. The mean age of HF patients was at least 10 years lower than the results of studies conducted in communities in other countries, indicating that our population is more exposed to factors associated with the development of HF^{2,6,10,11,28-31}. Several studies have shown an increased prevalence of HFpEF with aging, especially in populations of elderly women^2,6,10. This may be attributed to a greater control of diseases and risk factors involved in HF which has reduced the number of HFrEF cases. The predominance of HFpEF among elderly women is probably associated with the loss of the protective effect of estrogen on the cardiovascular system after menopause¹⁰.

The EPICA study, conducted in inland Portugal to evaluate the prevalence of HF, showed a greater prevalence of HFpEF than HFrEF (40% versus 30%), especially among women aged 60 years or more. Most patients were classified as I/II functional class (NYHA). Arterial hypertension (66%) and coronary artery disease (37%) were the main risk factors involved in HF². The EPICA-RAM study conducted in Portugal in the Autonomous Madeira region confirmed the same results of the EPICA study, with a lower rate of HFrEF (16%) and a higher rate of HFpEF (58%), which could be related to a higher rate of SAH (79.4%) and a lower rate of CAD (19.0%)⁶. These results are consistent with the results in the present study.

The prevalence of arterial hypertension (three times that of CAD), observed especially among HF patients, was greater than that observed in developed countries ^{2,6,10,17,31-33}. Arterial hypertension had a high prevalence in both forms of HF (HFrEF and HFpEF), with no differences between them. This contrasts with the results from other studies which showed a greater prevalence of arterial hypertension in HFpEF, indicating that within our environment the inadequate control of hypertension is one of the factors directly involved in the prevalence of HF, both HFpEF and HFrEF^2,6,32-35.

The larger number of cases of lower-limb edema identified among HFrEF patients was due to the greater severity of HFrEF in this population, confirmed by the presence of advanced functional classes (NYHA III/IV). Other factors involved in HFrEF were the presence of coronary artery disease, diabetes, chronic renal failure, greater number of hospital admissions and Boston scores > 5, confirming a more advanced and severe clinical presentation. In the elderly population, factors associated with HFrEF were hospitalization and Boston scores > 5, whereas in the population under 60 years of age, the factors were the significant presence of coronary artery disease and diabetes. These results are not consistent with those from other studies, showing that this population has its own characteristic progression of HFrEF^32-35. The association of these risk factors in patients less than 60 years of age shows that such factors are involved in the early onset and in the genesis of heart dysfunction in this population. Alcohol consumption and smoking were frequent lifestyle habits, especially in HFrEF, and played an important role in the development of this form of HF.

The homogeneous distribution of chronic obstructive pulmonary disease reduced the chance that this could be a decompensation factor for HF patients, although, due to the limitations of the study, no spirometry was performed.

Studies that evaluate the prevalence and forms of HF differ according to the criteria used to measure ventricular function (Table 3). The type of measurement used for ventricular function — the modified biplanar Simpson method or shortening fraction — and the cutoff level in these methods differ among the studies, determining a variance in the results of prevalence of HFrEF and HFpEF^10,14. The assessment of the ventricular function measured by the LV shortening fraction, using a 28% cutoff level which corresponds to an ejection fraction of 45% as per the Simpson method, proves to be the ideal choice for epidemiological studies in the community^2,6,14,27. The limitations of the shortening fraction method would apply to cases of myocardial structural abnormalities, either in the walls corresponding to the LV measurements or in apical dysfunction. Therefore, these measurements would not represent the actual measurement of the ventricular function. In these cases, structural abnormalities classify HF as systolic dysfunction since it is an important segment deficit responsible for the ventricular dysfunction which could not be expressed exclusively by the LV shortening fraction.

In conclusion, HFpEF is the most prevalent physiopathologic model in the community, especially among elderly women, whereas HFrEF affects mostly elderly men, is associated with greater clinical severity, early onset of the main risk factors and no changes in lifestyle. Despite the signs and symptoms of HF, this condition was not confirmed for one-third of the cases.

Potential Conflict of Interest

No potential conflict of interest relevant to this article was reported.

Sources of Funding

There were no external funding sources for this study.

Study Association

This article is part of the thesis of master submitted by Marco Aurelio Esposito Moutinho, from Universidade Federal Fluminense.

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Publication Dates

• Publication in this collection
  28 Apr 2008
• Date of issue
  Feb 2008

History

• Accepted
  08 Oct 2007
• Reviewed
  20 Sept 2007
• Received
  02 Aug 2007