13N-ammonia myocardial perfusion imaging with a PET/CT scanner: impact on clinical decision making and cost-effectiveness

Purpose: The purpose of the study is to determine the impact of 13N-ammonia positron emission tomography (PET) myocardial perfusion imaging (MPI) on clinical decision making and its cost-effectiveness. Materials and methods: One hundred consecutive patients (28 women, 72 men; mean age 60.9 ± 12.0years; range 24-85years) underwent 13N-ammonia PET scanning (and computed tomography, used only for attenuation correction) to assess myocardial perfusion in patients with known (n = 79) or suspected (n = 8) coronary artery disease (CAD), or for suspected small-vessel disease (SVD; n = 13). Before PET, the referring physician was asked to determine patient treatment if PET would not be available. Four weeks later, PET patient management was reassessed for each patient individually. Results: Before PET management strategies would have been: diagnostic angiography (62 of 100 patients), diagnostic angiography and percutaneous coronary intervention (PCI; 6 of 100), coronary artery bypass grafting (CABG; 3 of 100), transplantation (1 of 100), or conservative medical treatment (28 of 100). After PET scanning, treatment strategies were altered in 78 patients leading to: diagnostic angiography (0 of 100), PCI (20 of 100), CABG (3 of 100), transplantation (1 of 100), or conservative medical treatment (76 of 100). Patient management followed the recommendations of PET findings in 97% of the cases. Cost-effectiveness analysis revealed lower costs of €206/patient as a result of PET scanning. Conclusion: In a population with a high prevalence of known CAD, PET is cost-effective and has an important impact on patient managemen

Accuracy of quantitative coronary angiography with computed tomography and its dependency on plaque composition: Plaque composition and accuracy of cardiac CT

Objective: To determine the impact of plaque composition on accuracy of quantitative 64-slice computed tomography coronary angiography (CTCA). Methods: The institutional review board approved this study; written informed consent was obtained from all patients. One hundred consecutive patients (42 women, mean age 64.6±9.4years, age range 39-87years) underwent CTCA and invasive quantitative coronary angiography (QCA) to determine (a) the diagnostic accuracy of CTCA for the detection of significant stenosis (diameter reduction of≥50%), and (b) the accuracy of stenosis grading. In CTCA stenosis severity was graded in 10% steps and evaluated separately for calcified and non-calcified coronary lesions using Pearson-linear-regression analysis, Bland/Altman-analysis (BA), and Mann-Whitney-U-test. Results: In 60/100 patients 139 significant coronary artery stenoses were identified with QCA. On a per-segment analysis, sensitivity of CTCA was 75.5%, and specificity was 96.6% (positive predictive value: 72.9%, negative predictive value: 97.0%). Quantification of stenosis grading correlated moderately between methods (r=0.60; P<0.001), with an overestimation by CTCA of 5.5% (BA limits-of-agreement −29 to 39%). BA limits-of-agreement were greater in calcified lesions (−29.2 to 45.6%; mean error 8.2%) than in non-calcified lesions (−25.9 to 30.2%; mean error 2.2%) and differed significantly (P<0.05). Conclusions: Diagnostic accuracy of CTCA is high, however agreement for quantitative lesion severity assessment between CTCA and QCA is moderate for calcified but superior for non-calcified lesion

(13)N-ammonia myocardial perfusion imaging with a PET/CT scanner: impact on clinical decision making and cost-effectiveness

PURPOSE: The purpose of the study is to determine the impact of 13N-ammonia positron emission tomography (PET) myocardial perfusion imaging (MPI) on clinical decision making and its cost-effectiveness. MATERIALS AND METHODS: One hundred consecutive patients (28 women, 72 men; mean age 60.9 +/- 12.0 years; range 24-85 years) underwent 13N-ammonia PET scanning (and computed tomography, used only for attenuation correction) to assess myocardial perfusion in patients with known (n = 79) or suspected (n = 8) coronary artery disease (CAD), or for suspected small-vessel disease (SVD; n = 13). Before PET, the referring physician was asked to determine patient treatment if PET would not be available. Four weeks later, PET patient management was reassessed for each patient individually. RESULTS: Before PET management strategies would have been: diagnostic angiography (62 of 100 patients), diagnostic angiography and percutaneous coronary intervention (PCI; 6 of 100), coronary artery bypass grafting (CABG; 3 of 100), transplantation (1 of 100), or conservative medical treatment (28 of 100). After PET scanning, treatment strategies were altered in 78 patients leading to: diagnostic angiography (0 of 100), PCI (20 of 100), CABG (3 of 100), transplantation (1 of 100), or conservative medical treatment (76 of 100). Patient management followed the recommendations of PET findings in 97% of the cases. Cost-effectiveness analysis revealed lower costs of 206/patient as a result of PET scanning. CONCLUSION: In a population with a high prevalence of known CAD, PET is cost-effective and has an important impact on patient management

Accuracy of quantitative coronary angiography with computed tomography and its dependency on plaque composition: Plaque composition and accuracy of cardiac CT

Objective: To determine the impact of plaque composition on accuracy of quantitative 64-slice computed tomography coronary angiography (CTCA). Methods: The institutional review board approved this study; written informed consent was obtained from all patients. One hundred consecutive patients (42 women, mean age 64.6 +/- 9.4 years, age range 39-87 years) underwent CTCA and invasive quantitative coronary angiography (QCA) to determine (a) the diagnostic accuracy of CTCA for the detection of significant stenosis (diameter reduction of >/=50%), and (b) the accuracy of stenosis grading. In CTCA stenosis severity was graded in 10% steps and evaluated separately for calcified and non-calcified coronary lesions using Pearson-linear-regression analysis, Bland/Altman-analysis (BA), and Mann-Whitney-U-test. Results: In 60/100 patients 139 significant coronary artery stenoses were identified with QCA. On a per-segment analysis, sensitivity of CTCA was 75.5%, and specificity was 96.6% (positive predictive value: 72.9%, negative predictive value: 97.0%). Quantification of stenosis grading correlated moderately between methods (r = 0.60; P < 0.001), with an overestimation by CTCA of 5.5% (BA limits-of-agreement -29 to 39%). BA limits-of-agreement were greater in calcified lesions (-29.2 to 45.6%; mean error 8.2%) than in non-calcified lesions (-25.9 to 30.2%; mean error 2.2%) and differed significantly (P < 0.05). Conclusions: Diagnostic accuracy of CTCA is high, however agreement for quantitative lesion severity assessment between CTCA and QCA is moderate for calcified but superior for non-calcified lesions