In vivo assessment of myocardial viability after acute myocardial infarction: A head-to-head comparison of the perfusable tissue index by PET and delayed contrast-enhanced CMR

• Published in: Journal of nuclear cardiology Vol. 24; no. 2; pp. 657 - 667
• Main Authors: Timmer, Stefan A.J., Teunissen, Paul F.A., Danad, Ibrahim, Robbers, Lourens F.H.J., Raijmakers, Pieter G.H.M., Nijveldt, Robin, van Rossum, Albert C., Lammertsma, Adriaan A., van Royen, Niels, Knaapen, Paul
• Format: Journal Article
• Language: English
• Published: New York Elsevier Inc 01-04-2017; Springer US; Springer Nature B.V
• Subjects: Cardiology; Contrast Media; Early Diagnosis; Feasibility Studies; Female; Heart attacks; Humans; Imaging; Infarction; magnetic resonance imaging; Magnetic Resonance Imaging, Cine - methods; Male; Medicine; Medicine & Public Health; Middle Aged; myocardial; Myocardial Perfusion Imaging - methods; myocardial perfusion imaging: PET; Myocardial Stunning - diagnostic imaging; Myocardial Stunning - etiology; myocardial viability; Nuclear Medicine; Original; Original Article; Oxygen Radioisotopes; oxygen-15 water; Positron-Emission Tomography - methods; Radiology; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; ST Elevation Myocardial Infarction - complications; ST Elevation Myocardial Infarction - diagnostic imaging; Water; LCX; magnetic resonance imaging; oxygen-15 water; PTI; myocardial; LVEF; CMR; LGE; LAD; RCA; myocardial viability; PCI; STEMI; Infarction; myocardial perfusion imaging: PET; AMI
• ISSN: 1071-3581; 1532-6551
• DOI: 10.1007/s12350-015-0329-7

Early recognition of viable myocardium after acute myocardial infarction (AMI) is of clinical relevance, since affected segments have the potential of functional recovery. Delayed contrast-enhanced magnetic resonance imaging (DCE-CMR) has been validated extensively for the detection of viable myocardium. An alternative parameter for detecting viability is the perfusable tissue index (PTI), derived using [15O]H2O positron emission tomography (PET), which is inversely related to the extent of myocardial scar (non-perfusable tissue). The aim of the present study was to investigate the predictive value of PTI on recovery of LV function as compared to DCE-CMR in patients with AMI, after successful percutaneous coronary intervention (PCI).
Thirty-eight patients with ST elevation myocardial infarction (STEMI) successfully treated by PCI were prospectively recruited. Subjects were examined 1 week and 3 months (mean follow-up time: 97 ± 10 days) after AMI using [15O]H2O PET and DCE-CMR to assess PTI, regional function and scar. Viability was defined as recovery of systolic wall thickening ≥3.0 mm at follow-up by use of CMR. A total of 588 segments were available for serial analysis.
At baseline, 180 segments were dysfunctional and exhibited DCE. Seventy-three (41%) of these dysfunctional segments showed full recovery during follow-up (viable), whereas 107 (59%) segments remained dysfunctional (nonviable). Baseline PTI of viable segments was 0.94 ± 0.09 and was significantly higher compared to nonviable segments (0.80 ± 0.13, P < .001). The optimal cut-off value for PTI was ≥0.85 with a sensitivity of 85% and specificity of 72%, and an area under the curve (AUC) of 0.82. In comparison, a cut-off value of <32% for the extent of DCE resulted in a sensitivity of 72% and a specificity of 69%, and an AUC of 0.75 (AUC PTI vs DCE P = .14).
Assessment of myocardial viability shortly after reperfused AMI is feasible using PET. PET-derived PTI yields a good predictive value for the recovery of LV function in PCI-treated STEMI patients, in excellent agreement with DCE-CMR.