Prevalence of Heart Failure and Its Subtypes in the Population of Developed Countries

Introduction

Heart failure (HF) is a clinical syndrome whose occurrence is globally higher in men than in women. The incidence in both sexes is relatively low before the age of 60, but there is a significant increase after this age threshold. The most significant risk factors for the development of HF include obesity, hypertension, diabetes, smoking, and ischemic heart disease. The occurrence of type 2 diabetes doubles the risk of HF in men and quadruples it in women.

According to the current 2021 guidelines of the European Society of Cardiology (ESC), HF is divided into three subgroups based on left ventricular ejection fraction (LVEF) values: heart failure with preserved EF (HFpEF; LVEF ≥ 50%), with mildly reduced EF (HFmrEF; LVEF 41-49%), and with reduced EF (HFrEF; LVEF ≤ 40%). Up to half of the hospitalized patients with heart failure are those with HFpEF, whose prevalence has recently been increasing due to advanced diagnostic capabilities and a higher occurrence of risk factors in the aging population.

Study Methodology

A non-interventional cross-sectional study conducted at the Health Local Unit of Matosinhos in Portugal included all patients over 18 years old examined at this integrated center of primary, secondary, and tertiary healthcare over 3 years. A total of 126,636 individuals with an average age of 52.2 years were included in the assessment; 57% were women.

The presence of type 2 diabetes (DM2) was defined as an HbA1c value > 47.5 mmol/mol or random blood glucose > 11.1 mmol/l. The occurrence of heart failure was confirmed based on echocardiographic examination and laboratory values of BNP and NT-proBNP, and the heart failure subtype was determined according to these measurements:

• HFrEF with LVEF ≤ 40% and either NT-proBNP ≥ 400 pg/ml (≥ 600 pg/ml in the case of atrial fibrillation/flutter [AF]), or BNP ≥ 100 pg/ml (≥ 125 pg/ml in the case of AF)
• HFnrEF, including HFpEF (LVEF ≥ 50%) and either NT-proBNP ≥ 200 pg/ml (≥ 600 pg/ml in the case of AF), or BNP ≥ 100 pg/ml (≥ 125 pg/ml in the case of AF) + the presence of ≥ 1 structural heart anomaly, and HFmrEF (LVEF 40-50%) and either NT-proBNP ≥ 200 pg/ml (≥ 600 pg/ml in the case of AF), or BNP ≥ 100 pg/ml (≥ 125 pg/ml in the case of AF) + the presence of ≥ 1 structural heart anomaly.

The threshold for statistical significance was set at p ≤ 0.001.

Findings

The overall prevalence of heart failure in the studied population was 2.13% (n = 2700), 2.20% in the age group over 50 years, and 10.88% in seniors over 80 years. The average age of individuals with heart failure was 74 years, and 51.6% were women. Atrial fibrillation was present in 41.1% of patients with heart failure, and diabetes in 44.7%.

HFrEF was diagnosed in 18.6% of patients. Their average age was 70 years compared to an average age of 74.7 years for patients with HFnrEF (i.e., HFpEF and HFmrEF), the proportion of women was 33.9% compared to 55.0% in the HFnrEF group, and 45.6% had a history of myocardial infarction compared to 28.4% of patients with HFnrEF. Patients with HFrEF also more frequently used cardiovascular medication, especially antiplatelet agents, ACE inhibitors, beta-blockers, and aldosterone receptor antagonists.

Discussion and Conclusion

Recent Portuguese research provided data on the prevalence of heart failure in the population of developed countries, including its subtypes. The results correspond to other published estimates in the adult population of developed countries. However, compared to the EPICA study conducted in Portugal more than 20 years ago, the current prevalence of heart failure was approximately half (2.13% vs. 4.36%). The definition of heart failure criteria, however, differed between the two studies – the EPICA study also included exercise intolerance, fluid retention, and the use of medication for heart failure therapy, while at that time the examination of natriuretic peptides and echocardiographic determination of LVEF were not yet available.

An important finding of the current study is that more than half of the patients with heart failure have preserved left ventricular ejection fraction (65.4%), which corresponds to current data on the increasing occurrence of HFpEF. This proportion is likely to continue increasing due to the aging population and the rising prevalence of cardiovascular risk factors such as DM2 and hypertension. Current guidelines mainly focus on the therapy of HFrEF, while HFpEF and HFmrEF are much more briefly addressed. The conclusions of current studies, however, highlight the high and increasing proportion of patients with HFpEF.

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Source: Gavina C., Carvalho D. S., Valente F. 20 years of real-world data to estimate the prevalence of heart failure and its subtypes in an unselected population of integrated care units. J Cardiovasc Dev Dis 2022 May 7; 9 (5): 149, doi: 10.3390/jcdd9050149.