Improving Myocardial Perfusion by Percutaneous Coronary Intervention Reduces Central Sympathetic Activity in Stable Angina

Background By stimulating sympathetic afferents, repetitive myocardial ischemia induces a state of increased sympathetic tone. Hypothesis Removing the ischemic trigger by revascularization using percutaneous coronary intervention (PCI) might thus reduce central sympathetic activity in symptomatically stable angina patients. Methods A total of 20 patients with stable angina ≥ New York Heart Association (NYHA) class II with persistent symptoms despite maximal pharmacological therapy and a clinical indication for PCI, were included in our study. Sympathetic nervous system activity was measured before and 1 month after PCI by a combination of techniques: direct muscle sympathetic nerve activity (MSNA), neurochemical (plasma catecholamine levels), and heart rate variability (HRV). Results All patients completed the study. After PCI there was a significant reduction in MSNA (pre‐PCI 72 ± 4 to post‐PCI 53 ± 4 burst/100 beats, P < .05) and low frequency/high frequency (LF/HF) ratio (3.7 ± 0.6 vs 2.4 ± 0.4, P < .05) consistent with a decline in sympathetic activity. Plasma norepinephrine levels were reduced after PCI, but this difference did not reach statistical significance (1.84 ± 0.17 vs 1.73 ± 0.13 nmol/L, P = not significant). Conclusion Coronary revascularization by PCI reduces sympathetic activity in patients with established myocardial ischemia. Copyright © 2010 Wiley Periodicals, Inc.