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These results suggest that warfarin may not prevent ischemic stroke in Japanese hemodialysis patients with chronic sustained AF. Adequately powered studies are needed to determine the risks and benefits of anticoagulation therapy in these patients.

The concentration of carnitine, which is essential to fatty acid metabolism, can decrease markedly in patients on long-term hemodialysis coincident with life-threatening cardiac damage. However, administration of L-carnitine improves the myocardial function of these patients. To evaluate the underlying events of this phenomenon, we used recently developed technology, ¹²³I-labeled β-methyl-p-iodophenyl-pentadecanoic acid (BMIPP) myocardial scintigraphy, as a test of myocardial fatty acid metabolism. Our results showed that the free carnitine concentration (19.2 ± 6.5 μmol/l) was lower in 11 chronically dialyzed patients than in 8 healthy controls (49.3 ± 7.7 μmol/l, p < 0.0001). Additionally the heart to mediastinal ratio (H/M) of BMIPP was higher for these patients than for the controls (1.91 ± 0.19 vs. 1.52 ± 0.24, p < 0.005), and the patients’ washout rate (WOR) of BMIPP was lower (17.2 ± 6.0 vs. 22.8 ± 4.2%, p < 0.05). After L-carnitine was administered orally to the patients at doses of 1 g/day for 1 month and 0.5 g/day for the following month, the concentration of free carnitine in their sera increased to 85.4 ± 27.0 μmol/l (p < 0.0001). Although the H/M ratio did not change (1.89 ± 0.20) with this treatment, their WOR increased to 21.9 ± 6.6% (p < 0.001), similar to that of controls. The left ventricular end-diastolic dimension and left ventricular fractional shortening remained unchanged, as shown by echocardiography. The results presented here denote that a carnitine deficiency in chronically hemodialyzed patients disrupts their myocardial fatty acid metabolism, which is improved by L-carnitine supplementation.

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Background Patients on long-term hemodialysis become deficient in carnitine and are frequently treated with carnitine supplementation to offset their renal anemia, lipid abnormality and cardiac dysfunction. The therapeutic value of carnitine supplementation on left ventricular hypertrophy (LVH) in patients with normal cardiac systolic function remains uncertain. Methods and ResultsThe cardiac morphology and function of 10 patients given 10 mg/kg of L-carnitine orally, immediately after hemodialysis sessions 3 times per week for a 12-month period were compared with 10 untreated control patients. Using echocardiography, left ventricular fractional shortening (LVFS) and left ventricular mass index (LVMI) were measured before and after the study period. As a result, amounts of serum-free carnitine increased from 28.4±4.7 to 58.5±12.1 mol/L. The LVMI decreased significantly from 151.8±21.2 to 134.0±16.0 g/m 2 in treated patients (p<0.01), yet the LVMI in untreated control patients did not change significantly (ie, from 153.3±28.2 to 167.1±43.1 g/m 2 ). However, LVFS values remained unchanged in both groups. Although L-carnitine promoted a 31% reduction in erythropoietin requirements, hematocrit and blood pressure did not change during the study period. Conclusions Supplementation with L-carnitine induced regression of LVH in patients on hemodialysis, even for those with normal systolic function. (Circ J 2008; 72: 926 -931)