Effect of short-term administration of high dose L-arginine on restenosis after percutaneous transluminal coronary angioplasty.

BACKGROUND

A single and local administration of L-arginine after balloon angioplasty enhances nitric oxide (NO) generation and inhibits lesion formation in animals.

OBJECTIVES

The present study assessed the effect of increasing NO to inhibit restenosis after percutaneous transluminal coronary angioplasty (PTCA) in humans by local and systemic administration of L-arginine, a precursor of NO in humans.

METHODS

L-arginine was administered to 34 consecutive patients with angina pectoris or old myocardial infarction via a cardiac catheter (500 mg/4 min) before PTCA, and via a peripheral vein (30 g/4 hr, for 5 days) after PTCA. Patients were treated between December 1998 and December 2000. Plasma concentrations of L-arginine, NO (as nitrite + nitrate) and cyclic guanosine monophosphate (cGMP) were measured before and after L-arginine administration. The control group consisted of 90 patients who underwent PTCA successfully without L-arginine administration in the period between July 1996 and November 1998. Baseline clinical and angiographic characteristics were compared between the two groups. All patients were followed by coronary angiography for 3 months after PTCA. Quantitative coronary angiography and restenosis rate were studied.

RESULTS

Baseline clinical and angiographic characteristics were not different between the two study groups. Despite a significant elevation in plasma L-arginine concentration after L-arginine administration, NO and cGMP did not increase significantly. After PTCA, the difference in restenosis rates between L-arginine and control subjects (34% vs 44%) was not significantly different.

CONCLUSIONS

Short-term administration of high dose L-arginine did not significantly change the restenosis rate after PTCA.