Background: Cyanotic patients with congenital heart disease (CHD) might be protected against atherosclerosis.
Methods and results: Atherosclerotic risk factors and carotid intima - media thickness (IMT) were investigated in adults with cyanotic CHD and in unaffected age- and sex-matched controls. Fifty-four cyanotic patients (30 men, mean age 38, range 19-60 years) and 54 controls were included. Mean transcutaneous saturation of the cyanotic patients was 81+/-6%. Mean carotid IMT adjusted for age was significantly decreased in cyanotic patients compared to controls (0.55+/-0.1 mm vs 0.58+/-0.08 mm: DeltaIMT =0.04 mm [SE 0.015], P=0.01). In cyanotic patients lower total cholesterol levels were observed (4.4+/-1 mmol/L vs 4.9+/-1 mmol/L; P=0.02), as well as lower thrombocyte levels (173+/-81 x 10(9) /L vs 255+/-54 x 10(9) /L; P<0.01), higher bilirubin levels (18.6+/-11 micromol/L vs 12.7+/-6 micromol/L; P<0.01), and lower diastolic and systolic blood pressure (71+/-9 mmHg vs 76+/-9 mmHg, P<0.01; 113+/-14 mmHg vs 124+/-12 mmHg, P<0.01, respectively).
Conclusions: In patients with cyanotic CHD carotid IMT, and hence atherosclerosis disease risk, was decreased. This might be due to a combination of reduced atherosclerotic risk factors such as lower blood pressure, lower total cholesterol levels, higher bilirubin levels and lower thrombocyte levels.