Computed tomography coronary imaging as a gatekeeper for invasive coronary angiography in patients with newly diagnosed heart failure of unknown aetiology

Aims To evaluate the accuracy of cardiac computed tomography (CT) in distinguishing CAD and non‐CAD heart failure (HF) and its effectiveness as a gatekeeper for invasive coronary angiography (ICA). Methods and results We prospectively included 93 symptomatic patients with newly diagnosed HF of unknown aetiology (59 men; mean age 53 ± 13) and EF 55 mm (women). In all patients, the CT calcium score (CTCS) was determined. CTCS = 0 excluded CAD HF. Additional CT coronary angiography (CTCA) was performed if CTCS >0. ICA was used as the gold standard for distinguishing between CAD and non‐CAD HF in patients with >20% luminal diameter narrowing on CTCA. CAD HF was defined as >50% luminal diameter narrowing in either (i) the left main coronary artery or proximal left anterior descending coronary artery or (ii) in multiple coronary arteries. Diagnostic accuracy and follow‐up data (20 ± 16 months) were collected for all patients. CTCS = 0 ruled out CAD HF in 43 patients (46%). The CT algorithm had 100% sensitivity, 95% specificity, 67% positive predictive value, and 100% negative predictive value for detecting CAD HF. Patients with CTCS = 0 or non‐CAD HF on CTCA had no coronary events during follow‐up, and ICA could have been safely avoided in 76 out of 93 patients (82%). Conclusion In patients with HF of unknown aetiology, cardiac CT combining CTCS and CTCA has high accuracy for detecting CAD HF and can be used effectively as a gatekeeper for ICA.