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Abstract

Carnitine is an important cofactor in the intermediary metabolism of the heart, and carnitine deficiency is associated with congestive heart failure. We therefore studied the effects of acute (IV bolus, 30 mg/kg body weight) and chronic administration (1.5 mg/d for 1 month) of propionyl-L-carnitine on hemodynamics, hormone levels, ventricular function, exercise capacity, and peak oxygen consumption in 30 patients with chronic congestive heart failure (NYHA II-III, mean EF 29.5 +/- 7%) in a phase II, parallel, single-blind, randomized, and placebo-controlled study. Acute administration of propionyl-L-carnitine caused a significant reduction in pulmonary artery and pulmonary wedge pressures at both day 1 (P < 0.001) and day 30 (P < 0.05) of the study but no other hemodynamics changes. Hormone levels did not change following acute administration of the drug. Chronic administration of propionyl-L-carnitine increased peak oxygen consumption by 45% (from 16.0 +/- 3 to 23.5 +/- 2 mL/kg/min, P +/- 0.001), exercise time by 21% (from 8.1 +/- 0.5 to 9.8 +/- 0.4 minutes, P < 0.01), and peak exercise heart rate by 12% (P < 0.01). These changes were concomitant with a reduction of pulmonary artery pressure. In the treated group, there was a slight, but significant (P < 0.01), reduction in left ventricular dimensions. Hemodynamics and hormones measured after 1 month of oral therapy remained unchanged, except for a fall in pulmonary artery pressures, with a nonsignificant trend towards a fall in filling pressures and plasma norepinephrine. The chronic changes in the propionyl-L-carnitine group were seen at 15 days of treatment, and no further changes in these parameters were seen at 1 month. We conclude that propionyl-L-carnitine increases exercise capacity and reduces ventricular size in patients with congestive heart failure. The drug has no significant effects on hemodynamics or neurohormone levels. The use of a single-blind design reduces the impact of the positive finding on exercise capacity.

<i>L</i>-Carnitine Treatment in Patients with Mild Diastolic Heart Failure Is Associated with Improvement in Diastolic Function and Symptoms

“…Improvement in echocardiographic parameters similar to our findings has been documented which validates our data [28]. The effect of L -carnitine treatment on ejection fraction has been inconsistent [28,29]. However, these studies lack a control group in contrast to our study showing a positive effect of L -carnitine treatment in comparison to a control group.…”

“…The effect of L -carnitine treatment in patients with heart failure has shown significant increases in exercise capacity, maximum exercise time, peak heart rate, and peak oxygen consumption consistent with a positive effect of L -carnitine treatment as was found in our population after L -carnitine treatment [28,29,30]. Improvement in echocardiographic parameters similar to our findings has been documented which validates our data [28]. The effect of L -carnitine treatment on ejection fraction has been inconsistent [28,29].…”

“…A multicenter trial CEDIM ( L -carnitine Ecocardiografia Digitalizzata Infarto Miocardico) showed a positive effect of L -carnitine on cardiac remodeling after myocardial infarction [27]. The effect of L -carnitine treatment in patients with heart failure has shown significant increases in exercise capacity, maximum exercise time, peak heart rate, and peak oxygen consumption consistent with a positive effect of L -carnitine treatment as was found in our population after L -carnitine treatment [28,29,30]. Improvement in echocardiographic parameters similar to our findings has been documented which validates our data [28].…”

“…L -Carnitine is essential for the utilization of pyruvate in the Krebs cycle which may improve muscle metabolism by L -carnitine supplementation. Oral propionyl- L -carnitine has been shown to improve exercise tolerance in heart failure patients in some studies [4] but not others [5]. It has been tested in patients requiring cardiac surgery [6], in patients with angina pectoris [7,8,9], acute myocardial infarction [10,11], shock [12] and peripheral vascular disease [13].…”

Effects of Oral Amino Acid Supplements on Functional Capacity in Patients with Chronic Heart Failure

“…Subsequently, several studies have shown that supplementation of a single AA in patients with HF was able to improve the functional capacity. Mancini et al17 observed in 60 patients affected by stable chronic HF that the supplementation of L-carnitine for six months improved the maximum exercise duration, and Anand et al18 described 30 patients with HF in whom the supplementation of L-carnitine for one month improved peak VO 2 and exercise duration. The major limitation of these early studies is the supplementation of a single type of AA.…”