Abstract 1904: Clinical Characteristics of Patients with Obstructive Coronary Lesions in the Absence of Coronary Calcification: An Evaluation by Coronary CT Angiography
It is commonly assumed that the absence of coronary calcification makes the presence of obstructive coronary atherosclerotic lesions highly unlikely. We evaluated the clinical characteristics of patients who had a symptomatic, high-grade coronary artery stenosis with absence of any detectable calficiation both in computed tomography and invasive angiography and compared the results to patients with stenoses in the setting of detectable coronary calcium
Methods: We retrospectively identified 15 consecutive symptomatic patients in whom a high grade coronary artery stenosis had been detceted in 64-slice or Dual Sorce CT coronary angiography (Siemens Sensation 64 or Siemens Definition, 120 kV, 50 to 85 ml of intravenous contrast at 5ml/s) in the absence of coronary calcium and in whom that finding had been confirmed by invasive coronary angiography. We assessed clinical presentation (“unstable”: all forms of acute coronary syndrome versus “stable”: stable chest pain or dyspnoea on exertion), as well as standard cardiovascular risk factors and compared the results to 45 consecutive symptomatic patients in whom both coronary calcium and coronary stenoses had been identified in computed tomography and invasive coronary angiography.
Results: The majority of patients with coronary stenoses in the absence of coronary calcium presented with “unstable” symptoms (NSTEMI or unstable angina), significantly more frequently than patients with detectable calcification (80% vs 24%, p = 0.0001). The age range of patients without calcium was 34 to 73 years, the mean age was younger (54±13 vs. 64±8 years, p = 0.001), but none of the risk factors showed a significant difference as compared to patients with calcification.
Summary: The presence of significant coronary artery stenosis in the absence of coronary calcium is possible. It is more likely in the setting of unstable angina or NSTEMI than in stable chest pain and occurs more frequently in younger patients.