Reverse perfusion-metabolism mismatch predicts good prognosis in patients undergoing cardiac resynchronization therapy: a pilot study.

BACKGROUND Cardiac resynchronization therapy (CRT) improves glucose metabolism in the septum of patients with heart failure, so in the present study the predictive value of combined fluorodeoxyglucose (FDG)-positron emission tomography (PET) and metoxy-isobutyl isonitrile (MIBI)-single photon emission computed tomography (SPECT) for the prognosis of patients undergoing CRT was investigated. METHODS AND RESULTS Fourteen patients (70.3+/-8.2 years) who underwent FDG-PET and MIBI-SPECT before implantation of a biventricular pacemaker were enrolled. The total number of matches, mismatches, reverse mismatches, summed difference score (SDS: sum total of FDG - MIBI scores) and SDS per segment (%SDS) in each of 5 areas of myocardium (septum, anterior, lateral, inferior area, apex) was calculated and compared between the survival groups (all survival: survival group; survival without ischemic heart disease (IHD): non-IHD survival group) and non-survival group. Both the number of reverse mismatch segments and the %SDS in the septum in the non-IHD survival group were significantly greater than in the non-survival group (3.2+/-1.6 vs 0.5+/-0.6, p<0.05; 0.62+/-0.61 vs -0.11+/-0.19, p<0.05). The receiver-operating characteristics curves for prognosis showed that the area under the curve for the number of reverse mismatch segments in the septum (0.93; confidence interval 0.61-0.98) was significantly greater. CONCLUSION A reverse mismatch pattern in the septum can predict a good prognosis for patients treated with CRT.