Repaired coarctation of the aorta, persistent arterial hypertension and the selfish brain

Background: 20-30% repaired aortic coarctation (CoA) patients develop hypertension, with significant cardiovascular morbidity and mortality. Vertebral artery hypoplasia with an incomplete posterior circle of Willis (VAH+ipCoW) is associated with increased cerebrovascular resistance before the onset of increased sympathetic nerve activity in borderline hypertensive humans, suggesting brainstem hypoperfusion may evoke hypertension to maintain cerebral blood flow: the “selfish brain” hypothesis. We now assess the “selfish brain” in hypertension post-CoA repair.
Methods: Time-of-flight magnetic resonance angiography from 127 repaired CoA patients (34±14 years, 61% male, SBP 138±19mmHg, DBP 76±11mmHg) was compared with 33 normotensive controls (42±14 years, 48% male, SBP 124±10mmHg, DBP 76±8mmHg). VAH was defined as <2mm and ipCoW as hypoplasia of one or both posterior communicating arteries.
Results: VAH+ipCoW was more prevalent in repaired CoA than controls (odds ratio: 5.795 [1.614–20.812], p=0.007), after controlling for age, sex and body mass index (BMI). VAH+ipCoW was an independent predictor of hypertension (odds ratio: 2.473 [1.173–5.212], p=0.017), after controlling for age, gender and BMI. Repaired CoA subjects with VAH+ipCoW were more likely to have difficult to treat hypertension (odds ratio: 3.286 [1.005–10.743], p=0.049). Neither age at time of repair nor any specific repair type were significant predictors of VAH+ipCoW in univariate regression analysis.
Conclusions: VAH+ipCoW predicts hypertension and difficult to treat hypertension in repaired CoA. It is unrelated to age at time of repair or repair type. CoA appears to be a marker of wider congenital cerebrovascular problems. Understanding the “selfish brain” in post-CoA repair may help guide management.