Significant coronary artery calcifications are well known predictor of procedural failure in interventional cardiology. They may negatively influence the immediate results of stent deployment and consequently, the mid and long term outcomes. Validated angiographic predictors of significant coronary calcifications are lacking.
The aim of this study is to define an angiographic scoring regarding the severity of coronary calcification based on the correlation between the angiographic findings and intravascular (IVUS) imaging that served as a gold standard modality for this evaluation.
Methods. The total of 47 coronary angiograms showing different degrees of coronary calcification and in whom IVUS imaging was performed were reviewed by two independent investigators and were classified according to their calcium extent. The angiographic parameters evaluated were: appearance of calcium deposits at one or both edges of artery silhouette (“edge criteria” 0, 1, 2) and visualization of calcium only at the moving loop or still frame as well (“moving criteria” 0, 1, 2). Angiographic calcification score was a summation of the two. We defined no calcification (score 0) and severe calcification (score 4) as calcium shadow been visible at both edges of artery silhouette and on still frame. Severe calcification was defined as extended to more than 180 degrees of the lumen diameter by IVUS.
Results. Agreement between investigators was excellent in detecting coronary calcification by angiography (kappa 0.845) and by IVUS (kappa 0.939) and substantial for evaluation an extent of calcification on angiography (kappa 0.629), and by IVUS (kappa 0.614, p180 degrees but low specificity 53 and 79 % (p<0.023) and high negative predictive value 98 and 100%. Only one case was allegedly estimated by both investigators as having recognizable calcification on angiography, had no evidence on IVUS.
Conclusions. In this small cohort of patients evaluated for a possible classification of coronary calcification (score 1-4) based on angiographic imaging, a moderate correlation between the angiographic score and circumferential span of wall calcium on IVUS was found. However, the maximal angiographic score of 4 provided high sensitivity for significant calcification found on IVUS with high negative predictive value. This real-world study may provide helpful tool for predicting severe coronary calcification based on simple angiographic scoring system, that may help in decision while choosing a strategy of coronary stenting.
