Pre-test Risk and Risk Factors as a Predictor of CTCA Severity and Calcium Score

Abstract

Background: Coronary artery disease CTCA is a tool that is primarily used to rule out coronary artery disease in low-risk patients and reduces unnecessary invasive testing. Methods: This study included 169 patients, referred to a single large-volume centre from October 2015 to October 2016. Risk factors and CTCA severity results were collected and pre-test probability was calculated. Multinomial regression, and ANOVA were used to assess their prediction of CTCA results. Results: Pre-test probability was a significant predictor of moderate to severe disease on the CTCA (p = 0.016) but not a significant predictor of minimal/mild disease. Smoking was a significant predictor of minimal to mild disease on CTCA compared to normal CTCA findings (non-smokers 0.1 log-odds, B = - 2.289, p = 0.034). Current smoking was a significant predictor of moderate/severe disease compared with non-smokers (0.05, B = -2.84, p = 0.023). All other risk factors were not predictive. Low-risk pre-test scores had significantly lower calcium scores (309) than moderate or high pre-test risk (517, 521 respectively, F (2,162) = 15, p < 0.01). However, there was no significant difference in calcium scores between the moderate and high pre-test groups. Conclusion: Pre-test risk appears to have some utility in predicting significant coronary artery disease on CTCA and calcium score, however it was not a reliable discriminator of normal vs mild/minimal disease. Smoking correlated with the presence of at least mild disease and is strongly correlated with moderate disease and low pre-test risk was associated with significantly lower calcium scores.