CREATINE SUPPLEMENTATION IN CHRONIC HEART-FAILURE INCREASES SKELETAL-MUSCLE CREATINE-PHOSPHATE AND MUSCLE PERFORMANCE

Background: Cardiac creatine levels are depressed in chronic heart fai lure. Oral supplementation of creatine to healthy volunteers has been shown to increase physical performance. Aim: To evaluate the effects o f creatine supplementation on ejection fraction, symptom-limited physi cal endurance and skeletal muscle strength in patients with chronic he art failure. Methods: With a double-blind, placebo-controlled design 1 7 patients (age 43-70 years, ejection fraction < 40) were supplemented with creatine 20 g daily for 10 days. Before and on the last day of s upplementation ejection fraction was determined by radionuclide angiog raphy as was symptom-limited 1-legged knee extensor and 2-legged exerc ise performance on the cycle ergometer. Muscle strength as unilateral concentric knee extensor performance (peak torque, Nm at 180 degrees/s ) was also evaluated. Skeletal muscle biopsies were taken for the dete rmination of energy-rich phosphagens. Results: Ejection fraction at re st and at work did not change. Performance before creatine supplementa tion did not differ between placebo and creatine groups. While no chan ge was seen in the placebo group compared to baseline, creatine supple mentation increased skeletal muscle total creatine and creatine phosph ate by 17 +/- 4% (P < 0.05) and 12 +/- 4% (P < 0.05), respectively. In crements were seen only in patients with < 140 mmol total creatine/kg d.w. (P < 0.05). One-legged performance (21%, P < 0.05), 2-legged perf ormance (10%, P < 0.05), and peak torque, Nm (5%, P < 0.05) increased. Both peak torque and 1-legged performance increased linearly with inc reased skeletal muscle phosphocreatine (P < 0.05). The increments in 1 -legged, 2-legged and peak torque were significant compared to the pla cebo group, (P < 0.05). Conclusions: One week of creatine supplementat ion to patients with chronic heart failure did not increase ejection f raction but increased skeletal muscle energy-rich phosphagens and perf ormance as regards both strength and endurance. This new therapeutic a pproach merits further attention.