Plasma carnitine levels as a marker of impaired left ventricular functions

L-Carnitine plays a role in the utilization of fatty acids and glucose in t he myocardium. Previous studies have indicated carnitine deficiency in pati ents with congestive heart failure. However, the extent of altered carnitin e metabolism and left ventricular function is not fully determined. This st udy is designed to determine if plasma L-carnitine levels can serve as a ma rker for impaired left ventricular function in patients with congestive hea rt failure. To test this hypothesis, plasma and urinary levels of L-carnitine were meas ured in 30 patients with congestive heart failure (CHF) and in 10 control s ubjects. CHF was due to dilated cardiomyopathy (DCM) and rheumatic heart di sease (RHD). Cardiac functions such as percentage of fractional shortening (%FS), ejection fraction (EF), left ventricular mass index (LVMI), were det ermined by echocardiography. All patients and control subjects had normal r enal functions. Plasma carnitine was significantly higher in patients with DCM (37.05 +/- 7 .62, p < 0.0001) and with RHD (47.2 +/- 8.04, p < 0.0001) vs. the control s ubjects (14.4 +/- 5.30 mg/L). Urinary carnitine was significantly higher in DCM (49.13 +/- 14.11, p < 0.0001) and in RHD 43.53 +/- 15.5, p < 0.0001), than the control (25.1 +/- 5.78 mg/L). Plasma carnitine level correlated si gnificantly with impaired left ventricular systolic functions in these pati ents: %FS < 25% (r = -0.38 and p = 0.038), EF < 0.55 (r = -0.502 and p = 0. 005) and LMVI > 124 gm/m(2) (r = 0.436, and p = 0.016). These data suggest that elevated plasma and urinary carnitine levels in patients with CHF coul d serve as a marker for myocardial damage and impaired left ventricular fun ctions.