Background
CAUGHT-CAD is a multi-centre Australian randomised trial of coronary calcium for risk evaluation and prevention in patients with a family history of coronary artery disease.
Coronary artery disease (CAD) remains a major cause of premature death and disability, and cost-effective primary prevention depends on accurately evaluating CAD risk. Although most people initially present with CAD when they develop new symptoms (e.g. angina), >20 per cent initially present with a sudden catastrophic event such as myocardial infarction, stroke or even sudden cardiac death. The spectre of these latter scenarios has motivated efforts to reduce the risk of individuals without defined disease.
Lifetime risk of CAD is doubled in people with a family history of premature CAD, yet this risk is not captured in most 5 or 10-year risk assessment algorithms. A promising marker of subclinical risk is coronary artery calcium scoring (CCS). This has been shown in observational studies to provide prognostic information that is incremental to the clinical assessment of CV risk, is relatively inexpensive and performed with a small radiation dose. However, the use of CCS in guiding prevention is not incorporated in Australian guidelines. Definitive evidence of the efficacy and cost-effectiveness of CCS is therefore of primary importance.
The proposed study will be the first randomised controlled trial (RCT) of the use of CCS, and will be targeted to relatives of patients with premature CAD. Control patients will undergo standard risk scoring but have blinded CCS results. In the intervention arm, treatment will be initiated based on CCS, applying the new ACC/AHA prevention guidelines. At three years, the effectiveness of intervention will be assessed on change in plaque volume at CT coronary angiography (CTCA), the extent of which has been strongly linked to outcome. The results will provide high-level evidence to inform the guidelines regarding the place of CTCA in risk assessment, specifically in patients with a family history of premature CAD.
Study design
A paper describing the study design of the trial was published in the American Heart Journal in 2018 — read a summary.
Completion of recruitment
Recruitment of patients to the CAUGHT-CAD trial finished in August 2018. We screened over 1000 patients and randomised 449 to calcium-score guided therapy or usual care. Over 90 per cent of volunteers have been able to take medications as planned. We are very keen to ensure that participants stay on their therapy — if you participated in the trial and have any questions, please don't hesitate to contact your study coordinator.
Follow-up
The first few patients, recruited in 2015, have returned for follow-up scans. In general, we are advising participants to stay on the study treatment until the results of the study are obtained, but this will not be complete until the end of 2020. We expect that a few participants may develop important changes on the scan that warrant changing therapy, or additional testing, and if that’s the case, the study team will be in touch.
Substudies
At your entry into the study, we asked if you would mind us being in touch about sub-studies related to your original involvement. You will receive contact from the team about these in the next couple of months.