Dynamic CT-based stress myocardial perfusion imaging may allow detection of hemodynamically significant coronary artery stenosis.

Objective To determine whether coronary computed tomography angiography (CTA) should be performed in patients with any clinical probability of coronary artery disease (CAD), and whether the diagnostic performance differs between subgroups of patients. Design Prospectively designed meta-analysis of individual patient data from prospective diagnostic accuracy studies. Data sources Medline, Embase, and Web of Science for published studies. Unpublished studies were identified via direct contact with participating investigators. Eligibility criteria for selecting studies Prospective diagnostic accuracy studies that compared coronary CTA with coronary angiography as the reference standard, using at least a 50% diameter reduction as a cutoff value for obstructive CAD. All patients needed to have a clinical indication for coronary angiography due to suspected CAD, and both tests had to be performed in all patients. Results had to be provided using 2×2 or 3×2 cross tabulations for the comparison of CTA with coronary angiography. Primary outcomes were the positive and negative predictive values of CTA as a function of clinical pretest probability of obstructive CAD, analysed by a generalised linear mixed model; calculations were performed including and excluding non-diagnostic CTA results. The no-treat/treat threshold model was used to determine the range of appropriate pretest probabilities for CTA. The threshold model was based on obtained post-test probabilities of less than 15% in case of negative CTA and above 50% in case of positive CTA. Sex, angina pectoris type, age, and number of computed tomography detector rows were used as clinical variables to analyse the diagnostic performance in relevant subgroups. Results Individual patient data from 5332 patients from 65 prospective diagnostic accuracy studies were retrieved. For a pretest probability range of 7-67%, the treat threshold of more than 50% and the no-treat threshold of less than 15% post-test probability were obtained using CTA. At a pretest probability of 7%, the positive predictive value of CTA was 50.9% (95% confidence interval 43.3% to 57.7%) and the negative predictive value of CTA was 97.8% (96.4% to 98.7%); corresponding values at a pretest probability of 67% were 82.7% (78.3% to 86.2%) and 85.0% (80.2% to 88.9%), respectively. The overall sensitivity of CTA was 95.2% (92.6% to 96.9%) and the specificity was 79.2% (74.9% to 82.9%). CTA using more than 64 detector rows was associated with a higher empirical sensitivity than CTA using up to 64 rows (93.4% v 86.5%, P=0.002) and specificity (84.4% v 72.6%, P<0.001). The area under the receiver-operating-characteristic curve for CTA was 0.897 (0.889 to 0.906), and the diagnostic performance of CTA was slightly lower in women than in with men (area under the curve 0.874 (0.858 to 0.890) v 0.907 (0.897 to 0.916), P<0.001). The diagnostic performance of CTA was slightly lower in patients older than 75 (0.864 (0.834 to 0.894), P=0.018 v all other age groups) and was not significantly influenced by angina pectoris type (typical angina 0.895 (0.873 to 0.917), atypical angina 0.898 (0.884 to 0.913), non-anginal chest pain 0.884 (0.870 to 0.899), other chest discomfort 0.915 (0.897 to 0.934)). Conclusions In a no-treat/treat threshold model, the diagnosis of obstructive CAD using coronary CTA in patients with stable chest pain was most accurate when the clinical pretest probability was between 7% and 67%. Performance of CTA was not influenced by the angina pectoris type and was slightly higher in men and lower in older patients. Systematic review registration PROSPERO CRD42012002780.

Compared with CMR, dynamic stress CT provides good diagnostic accuracy for the detection of myocardial perfusion defects and may differentiate ischemic and infarcted myocardium.

CT-derived MBF measurements at rest and stress with varying degrees of coronary stenosis show a valid difference but an underestimated correlation with microsphere-derived MBF in a porcine animal model.

Objectives To evaluate the diagnostic accuracy (DA) of CT-myocardial perfusion imaging (CT-MPI) and a combined approach with CT angiography (CTA) for the detection of haemodynamically relevant coronary stenoses in patients with both suspected and known coronary artery disease. Design Prospective, non-randomised, diagnostic study. Setting Academic hospital-based study. Patients 65 patients (42 men age 70.4±9) with typical or atypical chest pain. Interventions CTA and CT-MPI with adenosine stress using a fast dual-source CT system. At subsequent invasive angiography, FFR measurement was performed in coronary arteries to define haemodynamic relevance of stenosis. Main outcome measures We tried to correlate haemodynamically relevant stenosis (FFR < 0.80) to a reduced myocardial blood flow (MBF) as assessed by CT-MPI and determined the DA of CT-MPI for the detection of haemodynamically relevant stenosis. Results Sensitivity and negative predictive value (NPV) of CTA alone were very high (100% respectively) for ruling out haemodynamically significant stenoses, specificity, Positive predictive value (PPV) and DA were low (43.8, 67.3 and 72%, respectively). CT-MPI showed a significant increase in specificity, PPV and DA for the detection of haemodynamically relevant stenoses (65.6, 74.4 and 81.5%, respectively) with persisting high sensitivity and NPV for ruling out haemodynamically relevant stenoses (97% and 95.5% respectively). The combination of CTA and CT-MPI showed no further increase in detection of haemodynamically significant stenosis compared with CT-MPI alone. Conclusions Our data suggest that CT-MPI permits the detection of haemodynamically relevant coronary artery stenoses with a moderate DA. CT may, therefore, allow the simultaneous assessment of both coronary morphology and function.