Effect of Tiotropium on Heart Rate Variability in Stable Chronic Obstructive Pulmonary Disease Patients

BACKGROUND: The chronic use of the long-acting anticholinergic agent, tiotropium, in chronic obstructive pulmonary disease (COPD) has been linked in some reports to an increase in adverse cardiovascular effects. Decreased heart rate variability (HRV) is a condition seen in COPD patients that has also been linked to poor cardiovascular outcome. We aimed in this study to investigate changes in HRV caused by tiotropium administration to COPD patients in order to determine whether changes occurred that might contribute to an increase in adverse cardiovascular events. METHODS: Seventy patients with moderate-to-severe stable COPD were treated with once-daily dosing of tiotropium (two puffs of Spiriva Respimat, 2.5 μg solution) for 3 months. HRV, pulmonary function, and quality of life were measured before and after 1 and 3 months of therapy. RESULTS: Pulmonary function and quality of life improved significantly, after both 1 and 3 months of therapy. No significant change in HRV parameters occurred, except for a significant decrease in the high-frequency and increase in the low-frequency component of HRV at the 1-month assessment. CONCLUSION: Changes in HRV caused by tiotropium use are not sufficient to explain a possible increase in adverse cardiovascular events.