Impact of Hear Failure on Lungs in Patients With Heart Failure

Heart failure (HF) is a global disease, which affects 1-2% adults worldwide. It is believed that 60% of these patients have HF with reduced ejection fraction (EF≤40%; HFrEF), 24% have HF with mildly reduced (EF 41-49%; HFmrEF) and 16% have HF with preserved ejection fraction (EF ≥50%, HFpEF). Despite its high prevalence, there are still many aspects of the disease that are not well recognized yet. One of them is impact of HFpEF on function lungs. Previous studies focused on this topic are scarce and mainly concern patients with advanced HFrEF. It was documented that HFrEF may lead to both lung abnormal changes in chest imaging and lung function tests. It may sometimes lead to unnecessary diagnostic procedures. However, pathophysiology and clinical relevance between heart and lung function in HFpEF patients still need to be elucidated.

Thus the aim of the study is to determine whether pulmonary abnormal findings found both in chest imaging and pulmonary function tests are comparable in patients with HFpEF and HFrEF.

Patients:

The study will include 84 patients (42 with HFrEF and 42 with HFpEF) aged 50-90 years diagnosed with chronic HF (NYHA II/III) in a stable period.

Inclusion criteria

• Age: 50-90 years old
• Chronic heart failure (NYHA class II-III)
• Signed informed consent

Exclusion criteria

• No consent to the study
• Age: <50 or >90 years old
• Any chronic pulmonary diseases diagnosed before
• Acute respiratory infection 14 days before enrollment (fever ≥38°C and at least one additional symptoms of infection)
• Acute kidney injury or chronic kidney failure (stage 4 or 5)
• Acute hepatic failure

Power analysis and sample size calculations indicated that a sample size of 84 subjects would provide 80% statistical power to detect significant differences between the two groups (alpha = 0.05, beta = 0.20) assuming that abnormal findings in chest CT will be present in 60% of patients with HFrEF and in 30% of subjects with HFpEF.

Included patients will be examined by:

• echocardiographic examination of the heart
• X-ray and CT of the chest
• spirometry, plethysmography, diffusion capacity for carbon monoxide (DLCO)
• arterial blood gas testing
• assessment of lung hydration in ultrasound
• peripheral blood collection In patients with abnormal, suspected changes in the lungs revealed in the chest CT bronchoscopy and endobronchial ultrasound (EBUS) will be considered.

The primary outcome :

• difference in frequency of chest CT abnormalities (ground-glass opacities or interlobular septal thickening or pleural effusion or mediastinal lymphadenopathy) between patients with HFrEF and HFpEF

The secondary outcomes:

• difference in pulmonary function test results (FEV1, FVC, TLC, RV, DLCO)
• differences in arterial pO2 and pCO2
• differences in B- line score in lung ultrasound
• differences in concentration of blood biomarkers (troponin, CRP, NTproBNP, IL-6, TNF-α, sST2, Gal-3, GDF-15)

The results of the study will allow to better understand the pathomechanisms of the occurrence of lesions in lungs secondary to HF. Thus, it may enable to reduce unnecessary diagnostics in patients with HF in the future.

Inclusion criteria

• Age: 50-90 years old
• Chronic heart failure (NYHA class II-III)
• Signed informed consent

Exclusion criteria

• No consent to the study
• Age: <50 or >90 years old
• Any chronic pulmonary diseases diagnosed before
• Acute respiratory infection 14 days before enrollment (fever ≥38°C and at least one additional symptoms of infection)
• Acute kidney injury or chronic kidney failure (stage 4 or 5)
• Acute hepatic failure