(31)Phosphorus magnetic resonance spectroscopy to evaluate medical therapyefficacy in peripheral arterial disease - A pilot study

Background. Human and animal studies have shown that propionyl-l-carnitine, increasing carnitine content, improves the energy metabolism of ischemic s keletal muscle. The aim of the study was to evaluate the accuracy of Dopple r continuous wave, Treadmill test and (31)Phosphorus magnetic resonance spe ctroscopy in determining the efficacy of propionyl-E-carnitine in patients with peripheral arterial disease. Methods, Experimental design: Prospective study. Setting: University hospit al, Patients: Eighteen male patients with peripheral arterial disease (cate gory 3) and 8 healthy volunteers form the basis of the study, Patients quit smoking, start physical training (2-3 Km walk per day) and were assigned t o medical therapy consisting of propionyl-L-carnitine (8 patients) or place bo (10 patients), Patients were studied with Doppler continuous wave, Tread mill test and (31)Phosphorus magnetic resonance spectroscopy at day 0 and a t day 90, The following parameters were assessed by the principal component analysis: clinical (absolute claudication, ankle brachial index at rest an d at 2, 5 and 10 minutes after completing Treadmill exercises) and biochemi cal (inorganic phosphorus/phosphocreatine ratio and pH profiles at 20% and 50% of the maximum load, the recovery half time of phosphocreatine, number of exercise steps and slope of linear relationship between muscle power and inorganic phosphorus/phosphocreatine ratio), Results. Final evaluation showed a significant improvement of clinical and biochemical variables (p<0.05 and p<0.02 respectively). Breaking down the r esults on the basis of the two study arms, (31)Phosphorus magnetic resonanc e spectroscopy showed a significant improvement of biochemical variables in the group of patients treated with propionyl-l-carnitine (p<0.05) and was more sensitive in the evaluation of changes induced by 90-day treatment as compared with the other noninvasive examinations, Conclusions. P-31-MRS permits the evaluation of muscle metabolic effect ind uced by PLC after a 90-day-period in patients affected by category 3 of per ipheral arterial disease and it is a more sensitive tool in the evaluation of the pharmacological effects of medical therapy.