Abstract
1661
Objectives Myocardial perfusion imaging (MPI) has limitations in the presence of balanced multivessel disease and left main (LM) coronary artery disease (CAD), occasionally resulting in false-normal results. We aimed to determine whether the combined analysis of MPI and coronary artery calcification score (CACS) could improve the diagnostic accuracy of MPI in detection of CAD in Chinese population.
Methods A retrospective analysis of 188 suspected CAD patients who were referred for One-step examination of MPI combined with CACS and coronary angiography were performed finally. Fixed perfusion defects (scar) and reversible defects (ischemia) were considered abnormal findings for MPI. Significant CAD was defined as the presence of at least 1 coronary vessel stenosis of 50% or greater by the gold standard of coronary angiography. A receiver-operating-characteristic (ROC) analysis was performed for the subgroup of patients with negative MPI results. The optimal CACS threshold was determined as the cutoff that on ROC analysis resulted in the best sensitivity for the detection of significant CAD with an associated specificity of greater than 90%.
Results ① Seventy-three(38.8%) cases were confirmed as CAD of 188 patients, and 76 (40.4%) cases had abnormal MPI results. There were 25 CAD patients with normal MPI results, including 2 cases with LM disease, 5 cases of three-vessel disease (3-VD), 3 cases of 2-VD, 15 cases of 1-VD. ② One hundred and five (55.9%) of the 188 patients had no coronary artery calcification (CACS=0), 32 patients (17.0%) had mild CACS (0<CACS≤100), 27 patients (14.3%) had moderate CAC (100<CACS≤400), 24 patients (12.8%) had severe CAC (CAC>400). With the increase of the degree of coronary artery calcification, the proportion of abnormal MPI results and abnormal CAG stenosis were significantly increased. The CACS of abnormal MPI group was significantly higher than normal MPI group[(494.96 ± 850.83) vs. (38.15 ± 171.93), P <0.001]. Similarly, with rising CACS, a larger percentage of patients had CAD. ③ Receiver-operating characteristic analysis showed that CACS of greater than or equal to 95.1 was optimal cutoff for detecting CAD patients with negative MPI results. Combining MPI with CACS (at cutoff of 95.1) improved the sensitivity of MPI (from 65.8% to 80.8%) for the detection of CAD, in association with nonsignificant decrease in specificity (from 75.7% to 71.3%). Of the 25 CAD patients with negative MPI results, 11 (44%) showed abnormal CACS (CACS蠅95.1), consisted of 2 cases of LM disease (2/2), 5 cases of 3-VD (5/5) , 1 case of 2-VD (1/3) , 3 cases of 1-VD (3/15) .
Conclusions The optimal cutoff of CACS for diagnosing CAD patients was 95.1 in Chinese populations, which can offer incremental diagnostic information over MPI for identifying patients with significant CAD, especially for severe CAD with left main lesions or balanced multivessel disease.