Aims: It has been previously reported that the sensitivity and specificity of multislice computed tomography (CT) for detecting significant coronary artery disease (CAD) is high. However, regular sinus rhythm has been considered a prerequisite for an adequate examination, even though atrial fibrillation (AF) is common among patients evaluated for the presence of coronary heart disease. In this study, we investigated the sensitivity and specificity of dual-source CT (DSCT) to detect and rule out significant coronary stenoses in patients with AF referred for invasive coronary angiography.
Methods and results: One hundred and ten consecutive patients with AF who were admitted for a first diagnostic coronary angiogram were screened for participation. Out of these, 50 patients were excluded either due to renal insufficiency, inability to maintain an adequate breath hold or due to rapid AF non-responsive to β-blocker therapy (heart rate > 100 b.p.m.). Sixty remaining patients (mean age 71 ± 7 years) were included and subjected to CT angiography using DSCT within 24 h before invasive coronary angiography. A contrast-enhanced volume data set was acquired (330 ms gantry rotation, collimation 2 × 64 × 0.6 mm, retrospective electrocardiogram gating). Data sets were evaluated concerning the presence or absence of significant coronary stenoses and validated against invasive coronary angiography. A significant stenosis was assumed if the diameter reduction was ≥50%. Mean heart rate during CT was 70 ± 15 b.p.m. (range 32-107 b.p.m.). On a per-patient basis, the sensitivity and specificity for DSCT to detect significant coronary stenoses in vessels >1.5 mm diameter was 100% [14/14, 95% confidence interval (CI) 77-100] and 85% (39/46, 95% CI 71-94), respectively, with a negative predictive value (NPV) of 100% (39/39, 95% CI 91-100) and a positive predictive value (PPV) of 67% (14/21, 95% CI 43-85). On a per-artery basis, 240 vessels were evaluated (left main, left anterior descending, left circumflex, and right coronary artery in 60 patients, with 3 non-assessable vessels due to either severe calcification or motion artefacts which were considered positive for stenoses) with a sensitivity of 95% (21/22, 95% CI 77-100) and specificity of 94% (204/218, 95% CI 89-97); NPV was 99% (204/205, 95% CI 96-100), and PPV was 60% (21/35, 95% CI 38-80).
Conclusion: Our study demonstrates high sensitivity, specificity, and NPV of DSCT to detect significant CAD in selected patients with rate controlled AF.