Paradoxical increase in ambulatory systolic blood pressure in coarctation of aorta as compared to idiopathic hypertension

Abstract

Abstract Background The relationship between office vs ambulatory blood pressure (BP) indices is well-studied in patients with idiopathic hypertension, and based on these data, it is known that average 24-hour ambulatory BP is typically lower than office BP. However, emerging data show that office systolic BP (SBP) underestimates arterial afterload in patients with coarctation of aorta (COA), and minimal increase in stroke volume during low intensity exercise results in exaggerated rise in SBP as compared to those with idiopathic hypertension. We hypothesized that COA patients will have higher ambulatory SBP and a higher prevalence of masked hypertension compared to patients with idiopathic hypertension. Methods Case-control study of 118 COA patients and 118 patients with idiopathic hypertension matched by age, sex, body mass index and office SBP. Results Although both groups had similar office SBP (132±17 mmHg) by design, the COA group had paradoxical increases in 24-hour ambulatory SBP (135±14 vs 126±13, p<0.001) and daytime ambulatory SBP (142±16 vs 130±13, p<0.001), and less nocturnal dipping (−3±5 vs −9±4, p<0.001). The COA group also had a higher prevalence of masked hypertension (36 [31%] vs 14 [12%], p<0.001), and worse arterial function indices. Conclusion These findings underscore the potential limitations of relying on office SBP for screening/monitoring of hypertension in COA and potential pitfalls in extrapolating idiopathic hypertension guidelines recommendations to the treatment of COA. It also provides rationale for further studies to determine if pharmacologic BP interventions guided by ambulatory BP data will improve clinical outcomes in the COA population. Funding Acknowledgement Type of funding sources: None.