Study reveals which imaging tests best confirm heart disease after initial CT scan
A major analysis of 1,410 patients shows that follow-up imaging tests confirm dangerous heart blockages in less than half of abnormal CT scans, with performance varying significantly by test type. For hospitals and insurers, the findings could reshape which expensive second imaging procedures get ordered, potentially reducing unnecessary tests while improving diagnostic accuracy.
Originaltitel: Diagnostic yield of second-line functional imaging after an abnormal coronary computed tomography angiography: an individual patient-data meta-analysis
Abstract Aims Second-line functional imaging is recommended following an abnormal coronary computed tomography angiography (CCTA). However, evidence guiding the choice of imaging modality is limited. We assessed the diagnostic performance of second-line functional imaging using different invasive reference standards. Methods and results We conducted an individual patient-data meta-analysis of seven prospective diagnostic studies including 1410 patients (mean age 62 ± 8.1 years, 67% male) with abnormal CCTA [≥50% diameter stenosis (DS)], who underwent second-line functional imaging tests (dobutamine stress ECHO, SPECT, CMR, and/or PET) followed by invasive angiography with fractional flow reserve (FFR) and quantitative coronary angiography (QCA). Haemodynamically obstructive coronary artery disease (CAD) was defined as invasive FFR ≤0.80 or >90% visual DS; anatomically severe CAD as ≥70% DS by QCA. Pooled and per test, 904/1906 (47.2%) functional imaging tests had haemodynamically obstructive CAD, and 504/1906 (26.3%) functional imaging tests had anatomically severe CAD. In total, 730/1906 (38.3%) functional imaging tests were abnormal. Pooled sensitivity and specificity were 63% and 84% for haemodynamically obstructive CAD, and 81% and 77% for anatomically severe CAD. Findings were generally stable across sex and age. More advanced second-line functional imaging tests showed higher sensitivities, but lower specificities compared to less advanced techniques. Conclusion Second-line functional imaging after an abnormal CCTA enables identification of patients with anatomically severe CAD. In contrast, moderate stenoses (<70% DS) with FFR ≤0.80 do not consistently result in myocardial ischaemia detectable by functional imaging tests. Substantial diagnostic accuracy differences were found between non-invasive diagnostic test which need further investigation. Clinical trial identifiers NCT02264717, NCT03481712, NCT04707859, NCT01521468