Background: While sympathetic drive in pathophysiology and pharmacological therapy shapes our understanding of systolic heart failure, it is still unclear whether COPD is also associated with a potentially therapeutically targetable increase in sympathetic drive. The gold standard of sympathetic tone measurement, available only in a few centers worldwide, is invasive microneurographic measurement of muscle sympathetic activity. Burst rate (/minute) or incidence (adjusted for heart rate) then expresses sympathetic activity as the spontaneous discharge rate of sympathetic nerve fascicles measured with microneurographic electrodes as the gold standard.

Methods: In 9 COPD patients without a secondary cardiovascular disease, external and intraneural microneurographic stimulation was used to find the peroneal nerve in the leg and then invasive microneurographic measurement of muscular sympathetic activity was performed via this nerve and compared with data from healthy control subjects.

Results: In 9 COPD patients (age 66±9 years, BMI 22±4 kg/m², 3 male, Gold II-IV) there was no difference in heart rate compared to age, sex and BMI matched controls (HR 73.22±9.44 vs. 72.50±6.37 bpm, p=0.89). MSNA Burst rate was significantly increased in COPD patients compared to controls (33.31±6.72 vs. 20.25±4.99 bursts/minute, p=0.004), indicating increased sympathetic tone. Burst incidence was significantly increased in COPD patients compared to controls (45.57±9.35 vs. 28.73±9.45 bursts/100 bpm, p=0.01) too.

Conclusion: Sympathetic drive is increased in COPD patients independent of secondary cardiovascular disease. This could be used therapeutically in the future to improve the prognosis of COPD patients.