Abnormalities in myocardial contractility, metabolism and perfusion reserve in non-stenotic coronary segments in heart failure patients

Objective: Myocardial blood flow (MBF) reserve is impaired in congestive heart failure (CHF), while fluorine-18-deoxyglucose ((18)FDG) uptake is relatively preserved. To determine whether this mismatch could be interpreted as ischemia, we performed dobutamine stress echocardiography (DSE). Methods: 12 males with coronary artery disease (CAD) and CHF were compared with 12 controls with similar CAD but normal left ventricular (LV) function. MBF in non-infarct-related artery areas was assessed using [N-13]ammonia positron emission tomography (PET), at rest and after dipyridamole infusion and (18)FDG uptake was determined. DSE was performed with doses up to 40 mug/kg per min. Results: In areas with non-stenotic arteries MBF reserve was more impaired in CHF patients (1.6+/-1-0.6 vs. 2.2+/-0.5; CHF versus normal LV, respectively, P<0.05). MBF reserve was related to LV ejection fraction (r=0.6, P<0.05) and wall stress (r = -0.72, P<0.05). PET showed mismatch in 4+/-1% of the myocardium in normal LV, compared to 26+/-26% in CHF (P<0.05), coinciding with more ischemic wall motion abnormalities on DSE (21 vs. 4%; CHF versus normal LV, respectively, P<0.05). Conclusions: In CHF, mismatch was found in areas supplied by non-stenotic coronary arteries. Corresponding areas showed ischemic wall motions on DSE. These findings suggest that the condition of CHF may play a role in perpetuating myocardial failure by inducing myocardial ischemia. Follow-up studies to investigate the ischemia-CHF relationship in time would be needed. (C) 2002 Elsevier Science B.V. All rights reserved.