Association of hyperhomocysteinemia with left ventricular dilatation and mass in human heart

Background: Hyperhomocysteinemia is a risk factor for ischemic heart disease. Several other mechanisms apply also to dilative types of heart failure of various, non-ischemic etiologies. We hypothesized that hyperhomocysteinemia is associated with left ventricular (LV) dilatation and hypertrophy in dilative cardiomyopathy. Methods: Homocysteine was measured in 66 individuals with suspected cardiomyopathy. Cardiac magnetic resonance imaging was used to assess LV volume, mass, and wall stress. Results: Hyperhomocysteinemia (> 12 mu mol/L) was found in 45 patients (68%). LV mass was greater in these patients compared with individuals with normal homocysteine (83+/-27 vs. 67+/-19 g/m(2); p < 0.02). Homocysteine was increased in patients with increased brain natriuretic peptide >= 100 pg/mL (18.3+/-5.9 vs. 14.9+/-5.1 mu mol/L; p = 0.018). LV mass, LV end-diastolic and end-systolic volume (LVEDV, LVESV) were significantly increased in individuals in the upper quartile compared with the lower quartile (90+/-25 vs. 65+/-18 g/m(2), p = 0.021; 114+/-50 vs. 71+/-23 mL/m(2), p = 0.042; 76+/-51 vs. 36+/-22 mL/m(2), p = 0.045). LV dilatation (LVEDV >= 90 mL/m(2)) was more common in hyperhomocysteinemia (> 12 mu mol/L, p = 0.0166). Normalized LV mass was correlated with homocysteine (r = 0.346, p = 0.065). Homocysteine was not significantly correlated with LVEDV (r = 0.229, p = 0.065), LV end-diastolic wall stress (r = 0.226, p = 0.069) and LV ejection fraction. Conclusions: Hyperhomocysteinemia appears to be, at least in part, involved in a disproportional LV dilatation, where the ensuing hypertrophy is not sufficient to compensate for the increased wall stress. A potential mechanism is the hyperhomocysteinemia associated increase in oxidative stress that favors muscle fiber slippage. Clin Chem Lab Med 2010;48:555-60.