Effect of Balloon-Dilated Restenosis on Exercise Performance and Cardiac Function in Children After Coarctation Repair

Restenosis occurs commonly after aortic coarctation (CoA) repair, usually requiring treatment by balloon dilation. Its effect on physical exercise performance is not documented. A retrospective analysis of exercise testing and echocardiographic assessment was performed in children after CoA repair. A group without restenosis (= group 1) and a group with recoarctation, treated by single balloon dilation (= group 2) were compared by matching for age and gender at a 2:1 ratio. Group 1 included 40 children and group 2 comprised 21 children, with mean age of 12.3 ± 2.3y and 11.9 ± 2.9y (p = 0.536) at evaluation. Group 2 children were younger at CoA repair (group 1: median 32.0d (11.0-188.0)-group 2: 9.0d (5.5-19.0), p = 0.011). Arterial hypertension was frequently noticed (group 1: 23(57.5%)-group 2: 7(33.3%), p = 0.106). Echocardiography revealed comparable cardiac function properties, showing more left ventricular (LV) hypertrophy in all CoA patients compared to their peers (Posterior wall thickness z-value: 1.03 ± 1.65, p < 0.001)). Exercise results were generally comparable, despite small differences in favor of group 1 (predicted % peak VO2 = group 1: 95.2 ± 21.4%-group 2: 82.3 ± 10.5%, p = 0.024; peak VO2/kg = group 1: 38.9 ± 9.5 ml/min/kg-group 2: 33.8 ± 6.9 ml/min/kg, p = 0.034; VO2/WR slope = group 1: 12.6 ± 2.0 ml/min/watt-group 2: 11.3 ± 1.7 ml/min/watt, p = 0.018). Compared to uncomplicated coarctation patients, children developing a surgical restenosis after CoA repair, and treated effectively by balloon dilation, had lower-but still acceptable-oxygen uptake during exercise. As intrinsic cardiovascular function characteristics were similar, further study to evaluate the impact of non-disease-specific factors is mandatory.