Few studies have evaluated rapid progression of carotid stenosis on a large scale. We created a custom software algorithm to analyze an electronic medical record database, aiming to examine the natural progression of carotid stenosis, identify a subset of patients with rapid progression, and evaluate specific patient risk factors associated with this rapid progression.
Patients in a large integrated healthcare system who received 2 or more carotid ultrasounds from August 2010 to August 2018 were identified. We did not distinguish between those with an established carotid stenosis diagnosis and those with a screening ultrasound. We used our novel algorithm to extract data from their carotid ultrasound reports. Degrees of carotid stenosis were categorized into levels: level 1, 0%-39%; level 2, 40%-59%; level 3, 60%-79%; level 4, 80%-99%; and level 5, complete occlusion. The primary endpoint was rapid versus slow progression of carotid stenosis, with rapid progression defined as an increase of 2 or more levels within any 18-month period of the study, regardless of the date of the initial ultrasound. The association of demographic and clinical characteristics with rapid progression was assessed by univariable and multivariable logistic regression.
From a cohort of 4.4 million patients, we identified 4,982 with 2 or more carotid ultrasounds who had a median follow-up 13.1 months (range 0.1-93.7 months). Of these, 879 (17.6%) patients showed progression of carotid stenosis. Only 116 (2.3%) patients progressed to level 4 (80%-99% stenosis) from any starting level during a median time of 11.5 months. A total of 180 (3.6%) patients were identified as rapid progressors during a median follow-up time of 9.9 months. Final multivariable analysis showed that younger age (P<0.01), Caucasian race (P=0.02), lower body mass index (BMI) (P=0.01), a diagnosis of peripheral arterial disease (P=0.03), and a diagnosis of transient ischemic attack (P<0.01) were associated with rapid progression.
Using a novel algorithm to extract data from more than 4 million patient records, we found that rapid progression of carotid stenosis appears to be rare. While 17.6% of patients showed any degree of progression, only 3.6% were rapid progressors. Among those who had any disease progression, 20.5% were rapid progressors. While the overall incidence of rapid progression is low, patients who demonstrate any progression may warrant close follow-up, especially if they have the associated risk factors for rapid progression. The custom software algorithm may be a powerful tool for creating and evaluating large data sets.
Copyright © 2020. Published by Elsevier Inc.