Diagnostic Accuracy of Computed Tomography Coronary Angiography in Patients Presenting with Heart Failure of Unknown Etiology in the Middle East

OBJECTIVES: The purpose of this study is to assess the diagnostic performance of coronary artery calcium score (CACS), computed tomography coronary angiography (CTCA), and the prevalence of coronary artery disease (CAD) as etiology of heart failure (HF) in the Middle Eastern population. BACKGROUND: CTCA has several advantages compared to invasive coronary angiography (ICA). However, studies on the diagnostic accuracy of CTCA and CACS in detecting the prevalence of CAD in patients with newly diagnosed HF are lacking in the Middle East. METHODS: This study included 204 patients with symptoms of HF and ejection fraction (EF) of <50% by echocardiography who underwent CTCA for diagnosis of CAD within 3 months. The exclusion criteria were defined as patients with a history of CAD, percutaneous coronary intervention, or coronary artery bypass grafting. All patients with obstructive CAD based on CTCA were referred for ICA. In addition, 30 patients with normal CTCA also underwent ICA for verification. RESULTS: The mean age was 48 ± 13 years, 69% (n = 141) were male and 31% (n = 73) were female, mean left ventricular EF was 31% ± 9%, and mean CACS was 58 ± 120. Based on the CTCA results, 169 patients had normal or nonobstructive CAD, whereas 35 patients had obstructive CAD. ICA was performed in all 35 patients with obstructive CAD; 30 of them were confirmed as having abnormal ICA, and only 5 had nonobstructive CAD. In addition, 30 patients with normal CTCA underwent ICA testing and were confirmed as having normal ICA. The CTCA had 100% sensitivity, 84% specificity, 86% positive predictive value, and 100% negative predictive value. Of the total population, 30 (15%) who were documented as having obstructive CAD were classified as CAD HF based on ICA. The remaining 174 (85%) patients were classified as having no CAD HF based on normal CTCA and/or ICA. The prevalence of CAD HF based on ICA was 15%. There was a strong correlation between CACS and both CTCA and ICA, with P = 0.001 and 0.0048, respectively. CONCLUSION: In patients with newly diagnosed HF, CACS and CTCA had a 100% sensitivity and negative value as well as overall excellent diagnostic accuracy. CACS = 0 excluded CAD as the etiology of HF with correlation between CACS groups and both CTCA and ICA. The prevalence of CAD as etiology of HF in the study population was 15%.