3318. Lung Cancer Screening CT: Use of An Ordinal Coronary Artery Calcium Scoring System and Its Potential Impact on Patient Clinical Management
Authors * Denotes Presenting Author
  1. Tyler Cook; Virginia Commonwealth University School of Medicine
  2. Anup Sanghvi; Virginia Commonwealth University School of Medicine
  3. Emily Walzl; Virginia Commonwealth University Health
  4. Leroy Thacker; Virginia Commonwealth University Health
  5. Mark Parker; Virginia Commonwealth University Health; Virginia Commonwealth University School of Medicine
  6. Sarah Warner *; Biomedical Sciences
We investigated the application of an ordinal coronary artery calcium (CAC) scoring system on low-dose CT (LDCT) exams in our lung cancer screening program, the frequency and severity of CAC based-on demographics, and the impact elevated scores have on clinical management.

Materials and Methods:
This is a retrospective review of CAC scores reported on LDCTs in our program between January 2013 and July 2022. Our radiologists applied an ordinal CAC-score for the four epicardial coronary arteries. Vessels were scored on a 0 - 3-point scale. (0): no calcifications; (1): < 1/3 vessel affected; (2): > 1/3 < 2/3 vessel affected; (3): > 2/3 vessel affected. Maximum score: 12/12. Scores of 4 were deemed significant. We sought to answer five questions. (1) What percent of patients have CAC scores in each category? (2) What is the relationship between CAC score, age, race, and sex?; (3) What percent of patients already had stent(s) or prior CABG? (4) How many patients died during the study? (5) What is the relationship between CAC score 4 and initiation of pharmacotherapy or invasive procedures? Demographics, various therapeutic interventions, and CAC scores were acquired via the electronic medical record. All analyses were done using SAS. An alpha level of 0.05 was used for statistical analysis.

3,264 observations were made in 1,908 studies. Regarding our 5 questions: (1) Median CAC score was 3. 36.5% had scores < 4; 41% score 4. (2) More women (60%) had CAC 0-2. Equal numbers of men and women had scores 3-6. More men (71.4%) had CACs > 6. Regarding race: 57.3% Whites and 38.3% Blacks had CAC < 3: 66.5% Whites and 31.5% Blacks CAC 4. Median age for CAC < 4; 61-years; CAC 4 64-years. (3) 67 patients had prior CABG (70%) or stent(s) (30%). More men (70%) had stent(s) or CABG on baseline imaging. Regarding race, more Whites (70%) had baseline stent(s) or CABG than Blacks (25%), or other races (5%). Median age for stent(s) was 60 and CABG 65-years. (4) 44 patients died during the study: 28 men; 16 women; 27 White; 17 Black,1 other. Their median age 64-years. Cause of death was not identified in most cases. (5) There was a significant relationship between initiation of pharmacotherapy and higher CAC scores and procedural interventions and CAC scores (t = 27.11, <em>p</em> - value < .0001; t = 3.93, <em>p</em> - value < .0001 respectively). Patients with scores 4 more likely received pharmacologic therapy. Patients with scores 4 were less likely to undergo invasive procedures. Patients with scores 4 were 4.19X more likely to receive pharmacotherapy. Patients undergoing invasive procedures were 1.34X less likely to have scores 4 (1/0.7446 = 1.34).

Our study shows higher CAC scores are most often observed in older, White men. There was also a statistically significant relationship between CAC scores and pharmacotherapy and/or invasive procedures. Specifically, patients with scores 4 were more likely to receive pharmacologic therapy. Interestingly, patients with scores 4 were less likely to undergo invasive procedures.