31P-MR spectroscopic imaging in hypertensive heart disease

Hypertensive heart disease (HHD) causes structural changes (e.g., fibrosis) that result in diastolic and systolic myocardial dysfunction. Alterations of P-31 metabolism and cardiac energy impairments were assessed in patients with HHD by MR spectroscopy (MRS) and correlated with left ventricular systolic function. Thirty-six patients with HHD and 20 healthy controls (mean age 35.2 +/- 10.7 years) were examined with P-31-MRS at 1.5 T by using an ECG-gated CSI sequence. Twenty-five patients (mean age 64.3 +/- 9.3 years) had diastolic dysfunction, but preserved systolic function (HHD-D), whereas 11 patients (62.3 +/- 11.4 years) suffered from additional impaired systolic function (HHD-S). In both patient groups, the PCr/gamma-ATP ratio was lower than in the controls (controls: 2.07 +/- 0.17; P < 0.001), and in HHD-S was lower than in HHD-D (1.43 +/- 0.21 vs. 1.65 +/- 0.25; P=0.012). PCr/gamma-ATP ratios were linearly correlated with LVEF (Pearson's r: 0.39; P=0.025). In the HHD-S group, the PDE/gamma-ATP ratio was significantly lower (0.56 +/- 0.36) than in the controls (1.14 +/- 0.42; P=0.001). In contrast to the group of HHD-D patients, whose slightly decreased PCr/gamma-ATP ratios compared to controls may be explained by age differences, the more distinct changes observed in HHD-S patients indicate an altered energy metabolism. The observed metabolic changes were related to functional impairments, as indicated by a reduced LVEF. Reduced PDE/ATP ratios indicate changes in the phospholipid metabolism.