Determination of factors affecting the results of balloon angioplasty in coarctation of aorta

Coarctation of aorta is the fifth most common congenital heart disorder. It is observed in 6- 8 % of infants born with congenital heart disease. The standard treatment of aortic coarctation is surgery in all age groups. However, invasive treatments applied via catheter such as balloon angioplasty and placement of stents have been increasing in prevalence for the last 20 years. Balloon angioplasty was actually a method applied in re-coarctations arising after surgeries but rates of success in native coarctations and recoarctations are currently found to be similar. Invasive treatments are currently initial treatments of choice in native coarctation due to their high rates of success and reduced rates of complications. The aim of this study is to determine the features affecting the success rate, outcome and rate of recoarctation in patients, treated with balloon angioplasty for coarctation In this study, 53 patients who applied to the Pediatric Cardiology Department of the Istanbul Training and Research Hospital of Baskent University and diagnosed with coarctation of aorta who ultimately received ballon angioplasty between April 2007 and May 2012 were evaluated retrospectively. The mean age of the patients was 14.7 months (S.D. 35.5, Range 0.1- 198 months) while their mean weight was 7.8 kilograms (S.D. 8.9). Thirty of the patients were males (57.0 %) while 23 were females (43 %). The patients were divided in three groups according to their age; as 0- 3 months, 4- 12 months and those older than 12 months. Forty- seven of the patients had native aortic coarctation while six had post-operative, recurrent aortic coarctation. The age groups were compared in terms of arcus and isthmus z scores; both before and after balloon angioplasty. The z scores of arcus (p= 0.000, p=0.000) and isthmus (p=0.004, p=0.000) were found to differ significantly before and after balloon angioplasty in those between 0-3 months and those older than 12 months. The patients between 4- 12 months and those older than 12 months also differed significantly in terms of arcus (p= 0.005, p=0.026) and isthmus (p= 0.019, p=0.003) z scores. In the whole sample, mean systolic blood pressure gradient prior to angioplasty reduced from 35.8 mmHg (S.D. 18.2) to 13.8 (S.D. 10) mmHg (p=0.000). Also, the mean radius of the coarctation segment increased from 3.3 (S.D. 1.9) mm to 4.9(S.D. 2.6) mm (p=0.000). Also, the radii for ascending aorta, isthmus, distal aortic arch and abdominal aorta increased significantly after balloon angioplasty. The rates of successful outcome for ballon angioplasty were found to be 81 % for the whole sample, 79 % for 0- 3 months, 77 % for 4- 12 months, and 92 % for those older than 12 months. The age was found to be significantly related with re-coarctation (p=0.005). When the patients were divided into two groups according to their having re-coarctation, the radii for distal transverse arch, isthmus and coarctation segment, Z score for arch prior to balloon angioplasty and radii for distal transverse arch, isthmus, coarctation segment, abdominal aorta, z scores for arch and isthmus and gradient after ballon angioplasty were found to be significantly different. In patients with radius of isthmus less than or equal to 50 % of ascending aorta prior to balloon angioplasty, the frequence of re-coarctation was significantly higher (p=0.045). The prevalence of coarctation for the whole sample was 19 % (n=10). No complications related to procedure except vessel stenosis and loss of pulse was observed among patients. Balloon angioplasty is a safe treatment alternative for surgery in treatment of aortic coarctation. It allows for remission of symptoms of heart failure and application of surgery under elective conditions in newborn and infants younger than 3 months. Radii and z scores of distal transverse arch and isthmus and radius of the coarctation segment both before and after ballon angioplasty are important measures for recoarctation. Age and severe isthmus hypoplasia are significant risk factors for recoarctation.