Biological, Radiological, and Clinical Significance of Spotty Calcification in Coronary Artery Disease

Spotty calcification is a marker of microcalcification in coronary artery plaques, where it becomes large enough to be visible on imaging modalities such as computed tomography. Two prevailing hypotheses posit spotty calcification as either a passive indicator of unstable plaque or an active catalyst of plaque vulnerability. Alongside this conceptual development, there has been paired evolution in radiologic characterization, with various imaging modalities demonstrating commendable accuracy in identifying spotty calcification. Many studies have linked the presence of spotty calcification to plaque instability and have reported a higher frequency in culprit lesions leading to acute coronary syndrome. Researchers have thus explored medications such as statins, metformin, and omega-3 fatty acids for their impact on the development and progression of spotty calcification. However, the field lacks standardized definitions that will enhance the clinical utility of this finding. This paper summarizes the evidence that describes spotty calcification as a unique plaque phenotype, its radiologic characteristics on routine cardiac imaging modalities, and its clinical relevance as a novel radiomarker of vulnerable coronary artery disease. This paper benefits from a systematic review of the evidence and, where possible, meta-analysis of the available data to address key questions conclusively in each of 3 areas of interest.