P-31-MR spectroscopy for the evaluation of energy metabolism in intact residual myocardium after acute myocardial infarction in humans

Objective: experimental studies have demonstrated that acute myocardial inf arction (MI) alters energy metabolism even in non-infarcted adjacent tissue . In patients with subacute MI, the influence of the regional ischemic insu lt on energy metabolism of intact septal myocardium was analyzed using P-31 -Magnetic resonance spectroscopy (MRS). Patients and Methods: in eight patients with wall motion abnormalities in t he anterior wall P-31-spectra were obtained from non-infarcted adjacent sep tal myocardium, as well as infarcted anterior myocardium (voxel size 25 ccm each) 29 +/- 8 days after MI using a 3D-CST technique. Additionally, cardi ac function was analyzed using breath-hold cine MRL MRI was repeated 6 mont hs after revascularization to assess viability of infarcted segments. Eight age-matched healthy volunteers served as control group. Results: according to follow-up MRI 4/8 patients showed regional wall motio n recovery. Here, PCr/ATP-ratios were not significantly reduced in intact s eptal myocardium as well as infarcted anterior myocardium compared to healt hy volunteers (1.28 +/- 0.10 and 1.14 +/- 0.09 vs. 1.45 +/- 0.29). No recov ery of regional function was detected in 4/8 patients with-therefore-nonvia ble anterior myocardium. PCr/ATP-ratios were significantly reduced in intac t and infarcted myocardium compared with healthy volunteers as well as to p atients with wall motion recovery (0.77 +/- 0.17 and 0.49 +/- 0.23; P < 0.0 5). Discussion: these preliminary results indicate that energy metabolism is re duced in patients with persisting wall motion abnormalities after myocardia l infarction and revascularization in ischemically injured as well as in ad jacent non-injured myocardium. (C) 2001 Elsevier Science B.V. All rights re served.