A family history of early-onset CAD may promote enhanced development and progression of coronary atherosclerosis in a sibling population. Baseline algorithms may underestimate the risk of coronary incidents in susceptible individuals. CCTA provides a high diagnostic performance for the detection of atherosclerosis. However, there is a paucity of data concerning the prognostic value of this technology in relatives at familial risk of CAD.

To assess CV risk and pre-test probability of CAD in patients with atypical symptoms from high-risk families. To describe CCTA findings and data on coronary angiograms.

Fifty siblings of patients with premature (<60yrs) cardiac events were investigated. The CAD consortium was calculated (clinical model). Risk algorithms were compared (SCORE, FRS for hard coronary disease, PROCAM). Significant CAD was defined as ≥50% reduction in coronary luminal diameter.

Pre-test probability of CAD was low: CAD consortium <10% in 60%, SCORE <5% in 100%, FRS <10% in 88%, CAC scoring <100% in 71%. Conversely, PROCAM was >10% in 16 cases (32%). Only 12patients (24%) presented normal CCTA. Angiography was performed in 31cases (62%). Most patients presented no significant lesions (55%). Revascularization was performed in 8 patients (16%). In patients with abnormal CCTA findings (n=38), PROCAM was higher than FRS in 20 patients (53%). After investigation, lipid-lowering therapy was enhanced in 66% (Table 1, Fig. 1).

We investigated patients with family history and low pre-test probability of CAD. The reclassification of cardiac risk in middle-aged adults at familial risk is a fundamental issue in preventive cardiology. Most patients presented coronary atherosclerosis on CCTA. PROCAM is more appropriate. CCTA may become useful for the screening of subclinical atherosclerosis and the prediction of coronary risk, leading to the institution of appropriate and targeted preventive measures in patients at familial risk.