Follow-up of hypertension after aortic coarctation stent implantation based on safe and effective re-intervention: a retrospective cohort study.

Background: Stent implantation for aortic coarctation (CoA) is associated with anatomical and hemodynamic advantages. Although the anatomy is corrected after the intervention, patients often still suffer from hypertension during the follow-up. Its risk factors remain unclear. There are only a few studies on the long-term follow-up of hypertension after stenting. This study aimed to investigate the factors influencing systemic hypertension after CoA by transcatheter stent placement. Methods: A total of 82 patients (native CoA: 37; men: 53) who underwent stent implantation for CoA at a median age of 123 months (range, 40 days-44 years) between January 2004 and September 2012 were included in this study. Patients with native or recurrent CoA after surgery, simple CoA or complex CoA associated with other cardiac anomalies were recruited in this study. Only stents that were expandable to adult size were implanted. After the initial stent implantation, the patients were followed up for 76.7 months (range, 6-151 months). Those who met the indications for a re-intervention underwent a balloon dilatation or stent implantation to relieve restenosis and alleviate the hypertension caused by restenosis. Patients with hypertension were treated with anti-hypertensive agents. Results: In the initial intervention, 87 stents were implanted in 82 patients. Seventy-two patients (87.8%) were diagnosed with hypertension before treatment, but only 23 (28.0%) patients had hypertension at the last follow-up, which is a number significantly lower than that before the intervention (P<0.001). Cox regression analysis showed that age at stent implantation was significantly correlated with the incidence of hypertension, which indicates that the younger the patient receiving the intervention, the lower the incidence of hypertension. Moreover, the incidence of hypertension in follow-up is related to the diagnosis. It was higher in the patients with simple CoA than those with complex CoA. There was no significant correlation between native CoA and recurrent CoA. Conclusions: The incidence of hypertension after CoA stent implantation was significantly lower than that before the intervention. Age at stent implantation is an essential influencing factor for paradoxical hypertension after CoA stent implantation. Complex CoA in patients was related to a significantly lower prevalence of follow-up hypertension.