Accuracy and Anatomical information. CCTA has been shown to have the highest accuracy compared with all available non-invasive tests for the detection of angiographically significant stenosis, with a 91% sensitivity and 92% specificity^3-5. CCTA can accurately quantify the extent, severity, and composition of coronary plaques. It provides excellent images of coronary artery ostium stenosis and coronary artery anomalies that can be challenging to see (and sometimes missed) in Invasive Coronary Angiogram. While heavily calcified plaques are still a challenge for CCTA, with later generation scanners, we can now perform a scan in a single heartbeat, in patients with irregular heart beat and also rule out Pulmonary embolism and Aortic dissection at the same time.

Evidence of screening benefits in High Risk Asymptomatic populations. There is growing consensus to recommend CCTA for asymptomatic individuals with high 10-year cardiac risk (>20%)⁶. Diabetes mellitus is considered a CAD equivalent by European and American guidelines. But screening in this group is particularly challenging because angina is often absent, and functional tests less accurate. It has been shown that almost 17% of Asymptomatic Diabetic patients have multivessel disease and high-risk lesions that were consistently associated with the majority of cardiac events during 6-year follow-up⁷.

Early Treatment. CCTA is the only modality that allows us to identify early Coronary artery plaques. Functional tests will only be positive when the disease is severe enough to limit coronary blood flow. In one study in South Korea, out of 1000 Asymptomatic patients who were randomised to perform a CCTA, 215 were found to have Atherosclerotic plaques⁸. While there is consensus to whom to treat in symptomatic CAD patients, it is controversial for asymptomatic patients. Nonetheless, in the SCOT-HEART (Scottish Computed Tomography of the Heart; n = 4,146) trial, more patients who underwent CCTA were started on preventive treatment and this group had significantly lower rate of death from coronary heart disease or nonfatal myocardial infarction at 5 years, suggesting benefits of early detection and treatment⁹.

Being able to see the “disease” can also help convince some patients to go on medications.

Radiation. The NICE recommendation is partly based on the assumption that a CCTA radiation dose is about 1-2mSV. This is likely applicable for the latest generation CT-scanners. For 64-slices CT-scanners, the radiation dose can be up to 15mSV. In comparison, most individuals are exposed to natural radiation exposure of 2-3mSV/year.

Contrast Material. Small risk of renal impairment and allergic reaction. Would need a recent Renal Function test before procedure.

Cost. A CCTA costs between RM2000-3000 in many Klang Valley centres currently. A cost that maybe prohibitive to many as a screening test.

Currently, there are a few private Medical and Screening centres that do offer CCTA for cardiac screening. Ideally, the screening packages should be tailored to the needs and expectations of individuals. Coronary CT-Angiogram provides for early detection of Coronary Artery Disease.