Plasma homocysteine, B vitamins, and amino acid concentrations in cats with cardiomyopathy and arterial thromboembolism

Arterial thromboembolism (ATE) is a common complication of cats with cardio myopathy (CM), but little is known about the pathophysiology of ATE. In peo ple, high plasma concentrations of homocysteine and low B vitamin concentra tions are risk factors for peripheral vascular disease. In addition, low pl asma arginine concentrations have been linked to endothelial dysfunction. T he purpose of this study was to compare concentrations of homocysteine, B v itamins, and amino acids in plasma of normal cats to those of cats with CM and ATE. Plasma concentrations of homocysteine, vitamin B-6, vitamin B-12, folate, and amino acids were measured in 29 healthy cats, 27 cats with CM a lone, and 28 cats with both CM and ATE. No differences were found between g roups in homocysteine or folate. Mean vitamin B-12 concentration (mean +/- standard deviation) was lower in cats with ATE (866 +/- 367 pg/mL) and cars with CM (939 +/- 389 pg/mL) compared with healthy controls (1,650 +/- 700 pg/mL; P <.001). Mean vitamin B-12 concentration was lower in cats with ATE (3,247 +/- 1,215 pmol/ml) and cats with CM (3,200 +/- 906 pmol/ml) compare d with healthy control animals (4,380 +/- 1,302 pmol/ml; P = .005). Plasma arginine concentrations were lower in cats with ATE (75 +/- 33 nmol/mL) com pared with cats with CM (106 +/- 25 nmol/mL) and healthy control animals (9 6 +/- 25 nmol/ mL; P <.001). Vitamin B-12 concentration was significantly c orrelated with left atrial size. We interpret the results of this study to suggest that vitamin B-12 and arginine may play a role in CM and ATE of cat s.