Respiratory function in patients with chronic heart failure and different ranges of ejection fraction

Abstract

Spirometric respiratory impairment is a significant and well-studied predictor for cardiovascular fatality in heart failure. However, reports of the interrelation between spirometric indexes and structural alterations of the heart, particularly left ventricular ejection fraction (LVEF), are scarce. Apparently, the respiratory function differs in patients with different LVEF and influences their clinical phenotype. The aim of this study was to investigate features of external respiration in patients with chronic heart failure (CHF) and different LVEF values. Materials and methods. 78 patients with stable, functional class (FC) I-IV CHF were evaluated and divided into three groups based on their LVEF (impaired, midrange, and preserved). Assessment of the clinical status (Clinical Condition Scale, quality of life, 6-min walk test), EchoCG, and spirometry with the bronchodilation test were performed for all patients. Results. 59.1% of studied patients had normal pulmonary function. 25.6% of patients had restrictive ventilatory defects; 5.1% had obstructive disorders, and 10.2% had mixed disorders. In the patient cohort with restrictive disorders, 55% had FC I-II CHF and 45% had FC III-IV CHF; among patients with obstructive disorders, 25% had FC I-II CHF and 75% had FC III-IV CHF; and among patients with mixed disorders, 12.5% had FC I-II CHF and 87.5% had FC III-IV CHF. Normal ventilatory function was observed in 64.7% of patients with preserved LVEF, 30% of patients with midrange LVEF, and 58.9% of patients with impaired LVEF (<40%). Incidence of restrictive defects was higher in patients with midrange LVEF (40%). Conclusion. Study results indicated presence of both restrictive and obstructive, mixed disorders resulting from secondary changes in lungs due to pulmonary hypertension. Therefore, to improve the treatment tactics spirometry should be performed for all patients with heart failure for timely diagnostics, which would possibly allow to introduce elements of individualized therapy.