Abstract 16289: COPD in Congestive Heart Failure Contributes to Increased Sympathetic Nerve Activity Due to Impaired Baroreflex Sensitivity
Background: Chronic heart failure (CHF) and chronic obstructive pulmonary disease (COPD) are frequently associated and COPD is an established bad prognostic factor for CHF patient. We sought to assess if sympathetic hyperactivity, could explain progression, severity and outcome of CHF patient with COPD.
Methods and results: We prospectively studied 13 patients with both COPD and CHF and 13 control CHF patients. Patients were matched for age, gender, type of cardiomyopathy, left ventricular ejection fraction (LVEF), pulmonary arterial pressure (PAP) and BMI. We compared muscle sympathetic nerve activity (MSNA) and sympathetic baroreflex function assessed by the slope of the relationship between MSNA and diastolic blood pressure: CHF patients with COPD showed higher HR (74.7 ± 4.0 vs 63.0 ± 2.2 bpm; p=0.017); heart rate was significantly related to the degree of pulmonary abnormality expressed by FEV1 (both absolute and as a % of predicted; r2=0.3507; P=0.0014). MSNA was significantly higher in CHF patients with COPD compared with control (57.8±2.4 vs 48.7± 2.8 bursts/min; P=0.02). Regression analyses showed a significant correlation between the degree of sympathetic hyperactivity (MSNA burst/min) and FEV1 (both absolute and as a % of predicted; r2=0.2002; P=0.02; figure), Respiratory Rate (r2=0.3588; P=0.0086) and Heart Rate (r2=0.2522; P=0.0089). Baroreflex gain, used to assess the baroreflex control of sympathetic nerve activity, was significantly decreased in patients with HF and COPD compared with patients with HF solely (2.05 vs 2.60 %MSNA/mmHg; p=0.008).
Conclusions: In CHF patients, COPD leads to a higher sympathetic activity and depressed baroreflex function. These finding are correlated with the severity of COPD and could explain the progression and prognosis of CHF patients with COPD.
- © 2013 by American Heart Association, Inc.