Intracoronary infusion of L-arginine reversed the aging-associated impairment in endothelium-dependent coronary microvascular vasodilation to acetylcholine (correlation with age r=-0.37, p=0.19).
Does L-arginine improve aging-associated endothelium-dependent coronary microvascular dysfunction in patients with normal coronary angiograms?
Intracoronary L-arginine administration reverses the aging-associated impairment of endothelium-dependent coronary microvascular vasodilation in humans.
Effect estimate: r = -0.37
p-value: p=0.19
OBJECTIVES: This study investigated the hypothesis that aging selectively impairs endothelium-dependent function, which may be reversible by administration of L-arginine. BACKGROUND: An impaired response to acetylcholine with aging has been demonstrated in humans. However, the mechanisms underlying this impaired response of the coronary microvasculature remain to be determined. METHODS: We infused the endothelium-independent vasodilators papaverine and glyceryl trinitrate (GTN) and the endothelium-dependent vasodilator acetylcholine (1,3,10 and 30 micrograms/min) into the left coronary artery of 34 patients (27 to 73 years old) with atypical chest pain, negative exercise test results, completely normal findings on coronary angiography and no coronary risk factors. Coronary blood flow was measured with an intracoronary Doppler catheter. The papaverine and acetylcholine infusions were repeated in 14 patients (27 to 73 years old) after an intracoronary infusion of L-arginine (160 mumol/min for 20 min). RESULTS: There was a significant negative correlation between aging and the peak coronary blood flow response evoked by acetylcholine (r = -0.73, p < 0.0001). However, there was no correlation to papaverine (r = -0.04, p = 0.82) and GTN (r = -0.24, p = 0.17). The peak coronary blood flow response evoked by acetylcholine correlated significantly with aging before L-arginine infusion (r = -0.87, p < 0.0001), but this negative correlation was lost after L-arginine infusion (r = -0.37, p = 0.19). CONCLUSIONS: The results suggest that aging selectively impairs endothelium-dependent coronary microvascular function and that this impairment can be restored by administration of L-arginine, a precursor of nitric oxide.
Chauhan et al. (Sun,) conducted a other in Atypical chest pain with normal coronary angiography (n=34). L-arginine vs. Baseline (before L-arginine infusion) was evaluated on Correlation between aging and peak coronary blood flow response evoked by acetylcholine (r = -0.37, p=0.19). Intracoronary infusion of L-arginine reversed the aging-associated impairment in endothelium-dependent coronary microvascular vasodilation to acetylcholine (correlation with age r=-0.37, p=0.19).