Superiority of Computed Tomography Coronary Angiography Over Calcium Scoring to Accurately Evaluate Atherosclerotic Disease in a 35-Year-Old Man

Abstract

A 35-year-old man with juvenile onset diabetes mellitus presented with exertion-associated chest pain. His risk factors also included smoking, hyperlipidemia, and strong family history. As part of a research protocol, he received a calcium score as well as multislice (computed tomography [CT]) coronary angiography using a new, 16-slice scanner (Lightspeed 16, GE Systems).There was no detectable epicardial coronary calcium (Figure 1). However, his noninvasive coronary angiogram demonstrated a high-grade stenosis in his mid-left anterior descending artery (LAD) (Figure 2 and Figure 3). Additionally, there was a significant amount of plaque burden noted in the proximal LAD and right coronary artery (RCA) (Figure 4).Invasive cardiac catheterization confirmed the presence of an occluded mid LAD, with collateral circulation from the RCA. Angioplasty was performed, and a drug-eluting stent was placed. The proximal LAD, although clearly not normal angiographically, did not have any flow-limiting stenosis shown by invasive angiography.Noninvasive angiography clearly demonstrated a 40% diameter reduction and a large burden of soft plaque in the proximal LAD. The outer diameter of the artery was Ͼ5 mm as shown by CT angiography. The lumen of the proximal LAD measured~3 mm by both CT and invasive coronary angiography.This case demonstrates very clearly the difficulties in utilizing calcium scoring alone to screen for coronary artery disease in some patients. It also demonstrates the superiority of CT coronary angiography to evaluate coronary anatomy, and to demonstrate both the coronary lumen and the soft plaque in the artery wall. Particularly interesting is how well the CT angiogram demonstrates the severity of plaque burden in arteries that have no significant flow-limiting stenosis by invasive angiography.

Computed Tomographic Coronary Angiography: Experience at Baylor University Medical Center/Baylor Jack and Jane Hamilton Heart and Vascular Hospital

“…Thus, calcium scoring can underestimate the total amount of plaque in younger patients with high risk factors for CHD (e.g., diabetics) (6). In older patients, it becomes less useful in screening for the presence of CHD, since most patients over the age of 70 have coronary calcification regardless of degree of stenosis (7).…”