Association Between Medial Calcification and Chronic Thrombus: An Optical Frequency Domain Imaging Study.

BACKGROUND

The below the knee (BTK) arteries of legs with peripheral artery disease (PAD) frequently exhibit medial calcification and chronic thrombus. However, the relationship between chronic thrombus and medial calcification remains poorly understood.

AIMS: This study aimed to evaluate the association between chronic thrombus and medial calcification in the BTK arteries of patients with PAD using optical frequency domain imaging (OFDI).

METHODS

OFDI frames were analyzed in legs with PAD undergoing OFDI-guided endovascular therapy. Data regarding thrombus, medial calcification, and the type and extent of calcification were collected. The multivariate logistic regression analysis was used to find the OFDI factors significantly associated with chronic thrombus. The causes of chronic thrombus were examined.

RESULTS

A total of 5293 frames from 21 legs in 19 patients were analyzed. Among all frames, medial calcification and chronic thrombus were observed in 51% and 23%, respectively. The multivariate logistic regression analysis showed that medial calcification and the degree of arc-quadrant of medial calcification were significantly associated with chronic thrombus. Medial calcification-related thrombus was the most common cause of chronic thrombus (57%), followed by lipidic atherosclerosis (35%), calcified nodule (3%) and distal emboli (3%). The prevalence of chronic thrombus related to medial calcification increased as the degree of arc-quadrant of medial calcification increased.

CONCLUSIONS

Chronic thrombus was significantly associated with medial calcification in the BTK arteries. The major cause of chronic thrombus was medial calcification-related thrombus. This study proposed a potential mechanism by which medial calcification can induce chronic thrombus in the BTK lesions.