Carotid Artery Ultrasonography as a Screening Tool for Predicting Coronary Artery Disease: A Cross-sectional Study from Hilly State of Northern India

Abstract

Introduction: Coronary Artery Disease (CAD) is a major cause of morbidity and mortality worldwide; therefore, early diagnosis plays a crucial role in managing patients with CAD. Multidetector Computed Tomography (MDCT) allows non invasive visualisation of coronary arteries but has limited availability, involves radiation, and is costly. Carotid artery atherosclerosis can be assessed by Ultrasound (USG) in terms of Carotid Intima-media Thickness (CIMT) and carotid plaque assessment. These carotid USG parameters are associated with CAD and can be used to predict CAD in high-risk patients. Aim: To study the association and correlation between carotid artery atherosclerosis USG parameters (CIMT and carotid plaque) and CAD, using Computed Tomography Coronary Angiography (CTCA) as a reference. Materials and Methods: A cross-sectional study was conducted from January 2020 to October 2021 in the Department of Radiodiagnosis at Indira Gandhi Medical College, Shimla, Himachal Pradesh, India. In the present study, 31 patients with suspected CAD were enrolled. All patients underwent CTCA followed by carotid artery USG within two weeks. The association and correlation between carotid artery atherosclerosis on USG and CAD on CTCA were examined. Sensitivity, specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV), and accuracy were calculated using CTCA as the reference standard. Categorical data were analysed using the Chi-square test, with a p-value of <0.05 considered statistically significant. Results: The mean age of the patients was 54.06±10.79 years. The CAD was observed in 14 (45.1%) cases, of which 13 (92.8%) had significant CAD. Nine patients had raised CIMT, of which eight had CAD. Raised CIMT and CAD showed a significant association with sensitivity, specificity, PPV, NPV, and accuracy of 57.14%, 94.12%, 88.89%, 72.73%, and 77.42%, respectively. A positive correlation was found between CIMT values and the number of vessels with significant CAD (r= +0.67). A total of 7 patients (22.5%) had the presence of carotid plaque, of which 6 (88.57%) had significant CAD. A significant association was found between CAD and the presence of carotid plaque. Carotid plaque had sensitivity, specificity, PPV, NPV, and accuracy of 50%, 100%, 100%, 70.83%, and 77.42%, respectively, in predicting CAD. A positive correlation was observed between carotid plaque burden and the number of vessels with significant CAD (r= +0.56). Conclusion: There is a significant association between carotid ultrasonography parameters (i.e., CIMT, carotid plaque) and CAD. CIMT is a more sensitive parameter than carotid plaque in predicting CAD. However, carotid plaque is more specific for predicting CAD. Carotid artery ultrasonography can be used as a screening tool for predicting CAD and should be included in the work-up of patients with suspected CAD.