The incremental value of myocardial viability, evaluated by 18F-fluorodeoxyglucose positron emission tomography, and cardiovascular magnetic resonance for mortality prediction in patients with previous myocardial infarction and symptomatic heart failure

OBJECTIVES

To find the imaging mortality predictors in patients with previous myocardial infarction (MI), symptomatic heart failure (HF), and reduced left ventricle (LV) ejection fraction (EF).

METHODS

for the study 39 patients were selected prospectively with prior MI, symptomatic HF, and LVEF ≤40%. All patients underwent transthoracic echocardiography (TTE), single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI), 18F-FDG positron emission tomography (FDG PET). 31 patients underwent cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE). Patients were divided into two groups: 1 group - cardiac death; 2 group - no cardiac death. Myocardial scars were assessed on a 5-point-scale. Follow-up data was obtained.

RESULTS

Imaging features disclosed significant difference (p < 0.05) of defect score (CMR and SPECT-PET), LV end-diastolic diameter (EDD) (TTE), LVEDD index (CMR), LV global longitudinal strain (CMR) and LV global circumferential strain (CMR) between the groups. Predictors of cardiac death were: LVEDD index (TTE) and LV global longitudinal strain. The cut-off values to predict cardiac death were: defect score (CMR) 25 (AUC, 79.5%; OR 1.8, 95% CI 1.2-2.7), SPECT-PET defect score 22 (AUC, 73.9%; OR 0.5, 95% CI 0.3-0.7), LVEDD (TTE) 58 mm (AUC, 88.4%; OR 23.6, 95% CI 2.6-217.7), LVEDDi 30 mm/m2 (TTE) (AUC, 73.6%; OR 22.0, 95% CI 1.9-251.5), LVEDDi 33.6 mm/m2 (CMR) (AUC, 73.6%; OR 22.0, 95% CI 1.9-251.5), LV global longitudinal strain -13.4 (AUC, 87.8%; OR 2.1, 95% CI 1.2-3.7) and LV global circumferential strain -16.3 (AUC, 76.1%; OR 1.9, 95% CI 1.2-3.0).

CONCLUSIONS

Imaging features, such as defect score (CMR) >25, SPECT-PET defect score >22, LVEDD (TTE) >58 mm, LVEDDi (TTE) >30 mm/m2, LVEDDi (CMR) >33.6 mm/m2, LV global longitudinal strain -13.4 and LV global circumferential strain -16.3, may increase sensitivity and specificity of FDG PET and LGE CMR predicting of late mortality.

Comparative Analysis of Myocardial Viability Multimodality Imaging in Patients with Previous Myocardial Infarction and Symptomatic Heart Failure

Background and Objectives: To compare the accuracy of multimodality imaging (myocardial perfusion imaging with single-photon emission computed tomography (SPECT MPI), 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET), and cardiovascular magnetic resonance (CMR) in the evaluation of left ventricle (LV) myocardial viability for the patients with the myocardial infarction (MI) and symptomatic heart failure (HF). Materials and Methods: 31 consecutive patients were included in the study prospectively, with a history of previous myocardial infarction, symptomatic HF (NYHA) functional class II or above, reduced ejection fraction (EF) ≤ 40%. All patients had confirmed atherosclerotic coronary artery disease (CAD), but conflicting opinions regarding the need for percutaneous intervention due to the suspected myocardial scar tissue. All patients underwent transthoracic echocardiography (TTE), SPECT MPI, 18F-FDG PET, and CMR with late gadolinium enhancement (LGE) examinations. Quantification of myocardial viability was assessed in a 17-segment model. All segments that were described as non-viable (score 4) by CMR LGE and PET were compared. The difference of score between CMR and PET we named reversibility score. According to this reversibility score, patients were divided into two groups: Group 1, reversibility score > 10 (viable myocardium with a chance of functional recovery after revascularization); Group 2, reversibility score ≤ 10 (less viable myocardium when revascularisation remains questionable). Results: 527 segments were compared in total. A significant difference in scores 1, 2, 3 group, and score 4 group was revealed between different modalities. CMR identified “non-viable” myocardium in 28.1% of segments across all groups, significantly different than SPECT in 11.8% PET in 6.5% Group 1 (viable myocardium group) patients had significantly higher physical tolerance (6 MWT (m) 3892 ± 94.5 vs. 301.4 ± 48.2), less dilated LV (LVEDD (mm) (TTE) 53.2 ± 7.9 vs. 63.4 ± 8.9; MM (g) (TTE) 239.5 ± 85.9 vs. 276.3 ± 62.7; LVEDD (mm) (CMR) 61.7 ± 8.1 vs. 69.0 ± 6.1; LVEDDi (mm/m2) (CMR) 29.8 ± 3.7 vs. 35.2 ± 3.1), significantly better parameters of the right heart (RV diameter (mm) (TTE) 33.4 ± 6.9 vs. 38.5 ± 5.0; TAPSE (mm) (TTE) 18.7 ± 2.0 vs. 15.2 ± 2.0), better LV SENC function (LV GLS (CMR) −14.3 ± 2.1 vs. 11.4 ± 2.9; LV GCS (CMR) −17.2 ± 4.6 vs. 12.7 ± 2.6), smaller size of involved myocardium (infarct size (%) (CMR) 24.5 ± 9.6 vs. 34.8 ± 11.1). Good correlations were found with several variables (LVEDD (CMR), LV EF (CMR), LV GCS (CMR)) with a coefficient of determination (R2) of 0.72. According to the cut-off values (LVEDV (CMR) > 330 mL, infarct size (CMR) > 26%, and LV GCS (CMR) < −15.8), we performed prediction of non-viable myocardium (reversibility score < 10) with the overall percentage of 80.6 (Nagelkerke R2 0.57). Conclusions: LGE CMR reveals a significantly higher number of scars, and the FDG PET appears to be more optimistic in the functional recovery prediction. Moreover, using exact imaging parameters (LVEDV (CMR) > 330 mL, infarct size (CMR) > 26% and LV GCS (CMR) < −15.8) may increase sensitivity and specificity of LGE CMR for evaluation of non-viable myocardium and lead to a better clinical solution (revascularization vs. medical treatment) even when viability is low in LGE CMR, and FDG PET is not performed.