The impact of nuclear cardiology in the evaluation of patients

 

Registry for the Evaluation of the PROgnostic value of a novel integrated imaging approach combining Single Photon Emission Computed Tomography with coronary calcification imaging (REPROSPECT).

Eur Heart J Cardiovasc Imaging. 2012 Oct 30.
[Epub ahead of print]


Authors: Ghadri JR, Fiechter M, Fuchs TA, Scherrer A, Stehli J, Gebhard C, Kläser B, Gaemperli O, Lüscher TF, Templin C, Kaufmann PA.
 
Although an added diagnostic and prognostic value of the global coronary artery calcification (CAC) score as an adjunct to single-photon emission computed tomography (SPECT)-myocardial perfusion image (MPI) has been repeatedly documented, none of the previous studies took advantage of the anatomic information provided by the unenhanced cardiac CT. Therefore, no co-registration has so far been used to match a myocardial perfusion defect with calcifications in the subtending coronary artery. To evaluate the prognostic value of integrating SPECT-MPI with CAC images were obtained from non-enhanced cardiac computed tomography (CT) for attenuation correction to predict major adverse cardiac events (MACE). Follow-up was obtained in 462 patients undergoing a 1-day stress/rest (99m)Tc-tetrofosmin SPECT and non-enhanced cardiac CT for attenuation correction. Survival free of MACE was determined using the Kaplan-Meier method. After integrating MPI and CT findings, patients were divided into three groups (i) MPI defect matched by calcification (CAC ≥1) in the subtending coronary artery (ii) unmatched MPI and CT finding (iii) normal finding by MPI and CT. At a mean follow-up of 34.5 ± 13 months, a MACE was observed in 80 patients (33 death, 6 non-fatal myocardial infarction, 9 hospitalizations due to unstable angina, and 32 revascularizations). Survival analysis revealed the most unfavourable outcome (P < 0.001 log-rank test) for patients with a matched finding. In the present study, a novel approach using a combined integration of cardiac SPECT-CAC imaging allows for refined risk stratification, as a matched defect emerged as an independent predictor of MACE.

 

 

Hybrid myocardial perfusion SPECT/CT coronary angiography and invasive coronary angiography in patients with stable angina pectoris lead to similar treatment decisions.

Heart. 2012 Oct 19. [Epub ahead of print]

Authors: Schaap J, de Groot JA, Nieman K, Meijboom WB, Boekholdt SM, Post MC, Van der Heyden JA, de Kroon TL, Rensing BJ, Moons KG, Verzijlbergen JF.

To evaluate to what extent treatment decisions for patients with stable angina pectoris can be made based on hybrid myocardial perfusion single-photon emission CT (SPECT) and CT coronary angiography (CCTA). It has been shown that hybrid SPECT/CCTA has good performance in the diagnosis of significant coronary artery disease (CAD). The question remains whether these imaging results lead to similar treatment decisions as compared to standalone SPECT and invasive coronary angiography (CA). We prospectively included 107 patients (mean age 62.8±10.0 years, 69% male) with stable anginal complaints and an intermediate to high pre-test likelihood for CAD. Hybrid SPECT/CCTA was performed prior to CA in all patients. The study outcome was the treatment decision categorised as: no revascularisation, percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). Treatment decisions were made by two interventional cardiologists and one cardiothoracic surgeon in two steps: first, based on the results of hybrid SPECT/CCTA; second, based on SPECT and CA. Revascularisation (PCI or CABG) was indicated in 54 (50%) patients based on SPECT and CA. Percentage agreement of treatment decisions in all patients based on hybrid SPECT/CCTA versus SPECT and CA on the necessity of revascularisation was 92%. Percentage agreement of treatment decisions in patients with matched, unmatched and normal hybrid SPECT/CCTA findings was 95%, 84% and 100%, respectively. Panel evaluation shows that patients could be accurately indicated for and deferred from revascularisation based on hybrid SPECT/CCTA.

 

Diagnostic Accuracy of Cardiac Positron Emission Tomography versus Single Photon Emission Computed Tomography for Coronary Artery Disease: A Bivariate Meta-Analysis.

Circ Cardiovasc Imaging. 2012 Oct 10. [Epub ahead of print]

Authors: Parker MW, Iskandar A, Limone B, Perugini A, Kim H, Jones C, Calamari B, Coleman CI, Heller GV.

Positron emission tomography (PET) myocardial perfusion imaging (MPI) offers technical benefits over single-photon emission computed tomography (SPECT) MPI, but there has been no systematic comparison of their diagnostic accuracy for coronary artery disease. The Authors performed a bivariate meta-analysis of the published literature to compare the sensitivity and specificity of PET versus SPECT stress MPI for ≥50% stenosis of any epicardial coronary artery in patients with known or suspected coronary artery disease (CAD). The Authors searched MEDLINE and EMBASE from inception through January 2012 and the references of identified studies for prospective, English-language studies that evaluated the sensitivity and specificity of PET and/or SPECT MPI with coronary angiography as the reference standard and reported sufficient data to calculate patient-level true and false positives and negatives. Two investigators independently extracted patient and study characteristics; a third investigator resolved any disagreements. The Authors identified 117 studies, including 108 evaluating SPECT MPI, four evaluating PET MPI, and five evaluating both modalities. Bivariate meta-analysis demonstrated a significantly higher pooled mean sensitivity with PET [92.6% (95% Confidence Interval (CI), 88.3% to 95.5%)] compared to SPECT [88.3% (95% CI, 86.4% to 90.0%)] (p=0.035). No significant difference in specificity was observed between PET [81.3% (95% CI, 66.6% - 90.4%)] and SPECT [75.8% (95% CI, 72.1% - 79.1%)] (p=0.39). Few studies investigated coronary angiography with PET. Only five studies directly compared SPECT and PET. Conclusions: In a meta-analysis of 11,862 patients, PET MPI demonstrated a higher sensitivity for CAD than SPECT MPI. No difference in specificity was detected in the pooled analysis of PET and SPECT MPI.