Abstract 3824: Zero or Low Agatston Calcium Score Does Not Exclude Significant Coronary Stenosis in Symptomatic Patients Undergoing 64-Slice Cardiac Computed Tomography
Objectives: Multidetector computed tomography (MDCT) both detects coronary calcium and allows direct assessment of coronary stenosis (non-invasive coronary angiography). Low (<100) Agatston calcium score (CS) is believed to indicate less severe coronary artery disease (CAD). We evaluated to what extent absence of calcification (zero) or low (1–100) CS excludes coronary stenoses in pts undergoing MDCT for evaluation of a chest pain syndrome.
Methods: Among 668 pts with chest pain syndromes (38% acute, 62% chronic) referred for 64-slice MDCT scanning (Brilliance 64, Philips), we assessed degree of coronary stenosis by contrast-enhanced MDCT in all 231 pts found to have a zero (N=125) or low (N=106) CS. The study pts were young (51±12 vs 63±12 yrs in 437 pts with CS>100, p<0.0001), 104 (45%) were female, 29 (13%) had diabetes mellitus, 77 (33%) hyperlipidemia and 98 (42%) were hypertensive. Significant CAD on MDCT was defined as ≥1 coronary artery stenosis (≥50% luminal narrowing). MDCT results were compared to invasive coronary angiography (ICA) when available.
Findings: Obstructive CAD was present in 9/125 (7%) pts with zero and 18/106 (17%) pts with low CS (1–100)(p=0.03). Obstructive CAD was detected in 14/90 (16%) pts referred for suspected acute and in 13/141 (9%) pts with chronic chest pain syndrome (p=NS). MDCT and ICA findings were compared in a patient-based analysis. Among 27 pts with significant CAD on MDCT, ICA confirmed MDCT in 21/23 pts (2 false positive MDCT), while in 204 pts without significant CAD on MDCT, ICA confirmed MDCT in 29/32 patients who underwent ICA at discretion of treating physician (3 false negative MDCT).
Conclusions: 1. Obstructive coronary stenosis was found on MDCT in 7% pts with zero and 17% with low (1–100) coronary CS. 2. Significant stenoses were detected both in pts with acute and with exclude significant CAD in pts undergoing investigation of a chest pain syndrome.