Mild coarctation of aorta is an independent risk factor for exercise-induced hypertension

Exercise-induced hypertension is a predictor of cardiovascular events in patients with coarctation of aorta (COA). However, it is unclear whether mild COA diagnosis is an independent risk factor of exercise-induced hypertension. We hypothesized that for every unit increase in exercise, patients with COA (without hemodynamically significant coarctation) will have a higher rise in systolic blood pressure (SBP) compared with matched controls. One hundred forty-nine patients with COA (aortic coarctation peak velocity <2 m/s) who underwent exercise testing were matched 1:1 to controls using propensity score method based on age, sex, body mass index, hypertension diagnosis, and SBP at rest. We compared exercise-induced change in SBP between patients with COA and controls and also assessed the correlation between Doppler-derived aortic vascular function indices (effective arterial elastance index and total arterial compliance index) and exercise-induced changes in SBP. Compared with controls, patients with COA had a greater change in SBP per unit metabolic equivalent (β=2.86; 95% CI, 1.96-4.77 versus 1.07, 95% CI, -0.15 to 1.75; P=0.018) and per unit oxygen pulse (β=4.57; 95% CI, 2.97-7.12 versus 1.45, 95% CI, -0.79 to 2.09, P<0.001). There was a correlation between SBPpeak-SBPrest and elastance index (r=0.38, P=0.032) and between SBPpeak-SBPrest and total arterial compliance index (r=-0.51, P=0.001), suggesting an association between vascular dysfunction and exercise-induced BP changes. Patients with COA, without significant obstruction, had higher exercise-induced changes in SBP after adjustment for other risk factors for hypertension. Considering the already known prognostic importance of exerciseinduced hypertension, the current study highlights the potential role of exercise testing for risk stratification of patients with mild COA.