The current strategy for prevention of chronic hypertension in patients born with coarctation of the aorta is to repair the lesion as early in life as possible. This study from the United Kingdom evaluated the effectiveness of these early repairs in a large cohort of 199 children who had undergone repair at a mean age of .22 years. These patients, now 7 to 16 years old, had both 24-hour blood pressure monitoring and casual blood pressure measurements performed. Using the 24-hour monitor as the standard, the sensitivity and specificity of casual blood pressure measurements for the detection of hypertension in this population were calculated.
While none of the study subjects were considered active candidates for further intervention, 49 (34%) had echocardiographically detectable mild residual aortic arch obstruction. Mean 24-hour systolic blood pressure was greater than the 95th percentile in 47% of those with, and 19% of those without residual obstruction. Overall, 30% were hypertensive approximately 10 years after coarctation repair. Casual blood pressure exceeded the 95th percentile in 43% of those with, and 21% of those without residual obstruction. Sensitivity and specificity of casual blood pressure determinations were 66% and 88%, respectively.
Chronic hypertension is a well-recognized cause of premature morbidity and mortality.1 After coarctation repair, chronic hypertension is more commonly identified among those in whom the obstruction was relieved at an older age.2,3 Early repair and aggressive surgical technique have been emphasized for close to 2 decades, but the effectiveness of this approach has not been subjected to much scrutiny.
This important investigation uncovered 4 disturbing facts about early coarctation repair: 1) it has a high incidence of mild residual obstruction that does not meet classic criteria for re-intervention; 2) patients with mild residual obstruction are at very high risk for chronic hypertension; 3) those without residual obstruction are at lower, but still substantial, risk; 4) casual blood pressure measurement is an insensitive method to detect this problem.
Surgical optimists will point out that advances in surgical technique since the time this cohort underwent their operations have allowed better repairs at earlier ages. The notion that modern surgical timing and methods will make chronic post-repair hypertension an historical curiosity is prevalent and seductive. So far, however, the available data would not support such a rosy view.
This report suggests that children who have undergone coarctation repair over the past 2 decades should be carefully screened for hypertension. An off-the-cuff, spot blood pressure measurement does not appear to be adequate for this vulnerable group of patients. In the UK, 24-hour blood pressure monitoring may now be the sterling standard, and may become the gold standard in the US.