IDENTIFICATION AND REVASCULARIZATION OF HIBERNATING MYOCARDIUM IN ANGINA-FREE PATIENTS WITH LEFT-VENTRICULAR DYSFUNCTION

We examined 17 angina-free patients with left ventricular dysfunction, referred for surgical decision-making, who presented with no or few s igns and symptoms of myocardial ischemia according to treadmill stress test. On cardiac catheterization they were affected by severe multi-v essel coronary artery disease; the mean left end-diastolic pressure of this population was 26.3 +/- 5.5 mmHg (mean +/- SD) and their mean ej ection fraction was 27.6 +/- 4.9% (mean +/- SD). They all were investi gated for the presence of viable myocardium by the combined assessment of cardiac perfusion and metabolism using single photon emission tomo graphy with [Tc-99m] labelled hexakis-2-methoxy-isobutyl-isonitrile [T c-99m]MIBI/SPET) and positron emission tomography with [F-18]-2-fluoro -2-deoxy-D-glucose ([F-18]FDG/PET), respectively. Patients were consid ered for coronary surgery when [F-18]FDG was detectable in at least tw o cardiac segments with wall motion abnormalities and perfusion defect s. Nine patients were operated on, six were medically treated and two were scheduled for heart transplantation. We recorded no in-hospital m ortality. At a mean follow-up of 28.4 +/- 9.8 (mean +/- SD) months all surgical patients were alive and their NYHA functional classes have i mproved, except in one case. Among the patients refused for bypass sur gery, three are in stable conditions, three have worsened clinical sta tuses and two died while waiting for heart transplantation. In conclus ion, for patients with bypassable coronaries, left ventricular dysfunc tion and lack of angina, successful coronary revascularization may be predicted by the presence of viable myocardium demonstrated with posit ron emission tomography.