Abstract 13333: Restrictive Lung Function is Related to Sympathetic Hyperactivity in Patients With Chronic Heart Failure

Abstract

Introduction: Sympathoexcitation and impaired lung function are common characteristics of patients with severe heart failure (HF). However, whether impaired lung function is associated with sympathoexcitation independently of HF severity remains unknown. Hypothesis: We postulated that impaired lung function itself is associated with sympathetic overactivation independently of HF severity. Methods: Muscle sympathetic nerve activity and clinical variables were determined in 83 HF patients with left ventricular ejection fraction (LVEF) < 0.45. Abnormal spirometric findings with restrictive and obstructive changes were defined as reduced forced vital capacity (%FVC) < 80% and a ratio of forced expiratory volume in the first second to FVC (FEV1.0%) < 70%, respectively. Results: Restrictive and obstructive changes were identified in 17 and 21 patients, respectively. Muscle sympathetic nerve activity was higher in patients with, than without restrictive changes (p<0.01), but comparable in those with or without obstructive changes. Univariate analyses showed that %FVC, glomerular filtration rate, specific activity scale, brain natriuretic peptide level, LVEF, age and use of aldosterone receptor blockers were significant predictors of burst incidence. Multivariate analysis revealed that %FVC, LVEF and glomerular filtration rate were common independent factors of increased burst rate and burst incidence. Changes in %FVC during follow-up negatively correlated with changes in burst rate (n=11, p<0.01). Conclusions: Restrictive lung function is associated with increased sympathetic nerve activity independently of HF severity.