Correction of Endothelial Dysfunction in Chronic Heart Failure: Additional Effects of Exercise Training and Oral L-Arginine Supplementation.

The aim of this study was to analyze whether L-arginine (L-arg.) has comparable or additive effects to physical exercise regarding endothelium-dependent vasodilation in patients with chronic heart failure (CHF).

Endothelial dysfunction in patients with CHF can be corrected by both dietary supplementation
with L-arg. and regular physical exercise.

Forty patients with severe CHF (left ventricular ejection fraction 19 6 9%) were randomized
to an L-arg. group (8 g/day), a training group (T) with daily handgrip training, L-arg. and
T (L-arg. 1 T) or an inactive control group (C). The mean internal radial artery diameter was
determined at the beginning and after four weeks in response to brachial arterial administration
of acetylcholine (ACh) (7.5, 15, 30 mg/min) and nitroglycerin (0.2 mg/min) with a transcutaneous high-resolution 10 MHz A-mode echo tracking system coupled with a Doppler device. The power of the study to detect clinically significant differences in endothelium-dependent vasodilation was 96.6%.

At the beginning, the mean endothelium-dependent vasodilation in response to ACh,
30 mg/min was 2.54 6 0.09% (p 5 NS between groups). After four weeks, internal radial
artery diameter increased by 8.8 6 0.9% after ACh 30 mg/min in L-arg. (p , 0.001 vs. C),
by 8.6 6 0.9% in T (p , 0.001 vs. C) and by 12.0 6 0.3% in L-arg. 1 T (p , 0.005 vs. C,
L-arg. and T). Endothelium-independent vasodilation as assessed by infusion of nitroglycerin
was similar in all groups at the beginning and at the end of the study.

Dietary supplementation of L-arg. as well as regular physical exercise improved agonistmediated,
endothelium-dependent vasodilation to a similar extent. Both interventions together seem to produce additive effects with respect to endothelium-dependent vasodilation.




重症CHF(左室駆出率199%)の患者40人を、L-arg群(8 g /日)と毎日ハンドグリップ・トレーニングを行うトレーニング群(T)、L-argおよびT(L-argT)、または不活性な対照群(C)に無作為に割り付けた。平均橈骨動脈内径を、開始時と4週間後に、アセチルコリン(ACh)(7.5、15、30 mcg/分)とニトログリセリン(0.2 mg/分)の上腕動脈投与応答時に、ドップラー装置に結合した経皮高分解能10 MHz Aモード エコートラッキングシステムで測定した。試験の内皮依存性血管拡張において臨床的に有意な差異を検出する検出力は、96.6%であった。

開始時、30 mcg/分のAchに応答した平均内皮依存性血管拡張は、2.540.09%(群間p = NS)であった。4週間後、30 mcg/分のAch後の橈骨動脈内径は、L-arg群で8.80.9%(p0.001 vs. C)、T群で8.60.9%(p0.001 vs. C)、L-argTで12.00.3%(p0.005 vs. C、L-arg及びT)増加した。ニトログリセリン注入によって評価した内皮非依存性血管拡張は、試験の開始時、終了時とも、全群で同様であった。