Transcatheter Therapy for Native Coarctation: Ready for Primetime as the First-Line Procedure of Choice?

Although percutaneous balloon angioplasty (BA) and endovascular stent implantation are generally accepted as the therapies of choice in cases of post-surgical recoarctation of the aorta, questions remain regarding whether these procedures should replace surgery in cases of native coarctation of the aorta (COA). Despite the uncertainty, many centers employ percutaneous intervention as first-line therapy for native coarctation in most infants, children, and adults in accordance with current guidelines from the American Heart Association (AHA) released in 2011.1 Angioplasty for native COA is a Class IIa indication as a palliative measure to stabilize a patient with severely depressed ventricle function. In addition, Class IIb indications include patients beyond four to six months of age with suitable anatomy (discrete COA). Regarding stenting, Class IIa indications include use of stents that can be dilated to adult size diameters in native (discrete or long segment) COA when angioplasty has failed. We argue that this is the correct approach based on available evidence, even in select neonates and young infants for whom there is evidence of particularly high recoarctation rates following BA.

Since the introduction of BA for native coarctation in the early 1980s,2,3,4 improvements in techniques and technology – including the use of balloon expandable stents – have rendered percutaneous intervention a viable and less invasive alternative to surgery. By 1990, multicenter data from early adopters of the procedure showed that among pediatric and adult patients, BA successfully reduced coarctation in over 80% of patients, increased the diameter of the coarctation in nearly all patients, and resulted in major complications in 10% of patients.5 With ongoing experience and technical advancements, more recent studies have consistently shown that in comparison to surgery, BA is now equally effective in acutely relieving discrete coarctation in neonates, infants, children, and adults, and procedural complications have become quite rare.6,7 Moreover, recent evidence from a multicenter consortium suggests that the use of stents in appropriately sized patients achieves superior acute relief of obstruction and lower rates of acute aortic wall injury compared to both surgery and BA.8 In early results from the Coarctation of the Aorta Stent Trial (COAST), the NuMed Cheatham Platinum Stent was delivered successfully in 99% of patients and reduced the mean coarctation gradient to a mere 2 mm Hg with no serious adverse events or deaths.9 Finally, BA and stenting are associated with considerably shorter durations of post-procedure intubation and hospitalization than surgery.10,11

Available data on intermediate- and long-term outcomes further indicate that percutaneous interventions offer a viable, and perhaps ultimately superior, alternative to surgery. True, BA alone results in tearing of the intima and injury to the media, which is thought to place patients at increased risk of recurrent obstruction and the formation of aortic aneurysms with the potential for rupture. Indeed, a recent meta-analysis of trials and observational studies found that those who underwent BA without stenting experienced higher rates of early recoarctation and later aneurysm formation. However, angioplasty patients who experienced recoarctation responded well to repeat angioplasty, did not experience higher rates of late recoarctation, and tended not to require surgical intervention.12 Furthermore, data indicate that the increasingly common use of stents results in significantly lower rates of intermediate-term aneurysm formation than surgical coarctation repair;13 and covered stents, one of which is currently under phase 2 investigation in the multicenter Covered Cheatham Platinum CP Stents for the Prevention or Treatment of Aortic Wall Injury Associated With Coarctation of the Aorta (COAST II) trial (ClinicalTrials.gov Identifier: NCT01278303), are likely to further reduce the risk of aneurysm in high-risk patients while also allowing for endovascular treatment of existing post-angioplasty aneurysms.14,15 While the use of aortic stenting today is largely limited to older children (25 kg and larger) and adults, in whom stents large enough to reach adult aortic proportions can be deployed, recent improvements in delivery techniques and the availability of small delivery systems such as 3 Fr sheaths and balloons for angioplasty and 7 Fr premounted stents that can eventually be expanded to 20 mm have also extended the procedure to smaller patients with lower vascular complications. In addition, emerging technologies, including bioresorbable stents,16 promise to extend stent availability to all age groups.

Despite the successes of percutaneous therapies, early studies suggested that neonates and younger infants (less than four to six months) were experiencing particularly high rates of recurrent coarctation after BA.17,18 As a result, many began considering BA as merely palliative in these patients and continued opting for surgical repair. However, in reviewing both the published literature and their institutional experience with patients under three months of age, Rao and colleagues19 concluded that BA of native coarctation was as acutely effective as surgery and resulted in lower morbidity and fewer complications. Aneurysm formation and other complications were rare, and although rates of recoarctation were high (45% in the institutional experience), the majority of young patients responded well to repeat angioplasty and did not require surgery during the follow-up period.

Moreover, symptomatic presentation during the neonatal period and early infancy is associated with anatomical features that may be unfavorable for BA without stenting, including arch hypoplasia and tubular hypoplasia of the isthmus. It is likely, therefore, that many publications from earlier eras reflect the outcomes of neonates and young infants with anatomically distinct lesions from those found in patients who present later in life. For example, Patel and colleagues20 reported that only 13 of 17 patients (76%) aged two weeks to nine months remained free from surgical intervention at 2.7 years post-BA; however, three of the four patients who required surgery were noted to have tubular hypoplasia as opposed to discrete coarctation, and BA was considered successful in 93% of patients with discrete coarctation. The authors concluded that pursuing the procedure in neonates and young infants with discrete lesions was reasonable. The point is particularly important since echocardiograms are ordered more frequently by physicians in the recent era resulting in more incidental findings of discrete lesions that may not have been diagnosed until later in life when BA is more routinely deployed.

In summary, percutaneous intervention for COA is a rapidly evolving and less invasive alternative to surgical repair that, in some patients, may offer superior outcomes. Ongoing innovation has made the optimal approach clearer in recent years and will undoubtedly expand the use of the safest and most effective techniques to the smallest of patients. As with all advances in medicine, when all is equal, therapies evolve from more invasive to less invasive over time. Transcatheter treatment for both native and recurrent COA is here to stay.

References

  1. Feltes TF, Bacha E, Beekman R, et al. Indications for cardiac catheterization and intervention in pediatric cardiac disease: a scientific statement from the American Heart Association. Circulation 2011;123:2607-52.
  2. Lababidi Z. Neonatal transluminal balloon coarctation angioplasty. Am Heart J 1983;106:752-3.
  3. Singer MI, Rowen M, Dorsey TJ. Transluminal aortic balloon angioplasty for coarctation of the aorta in the newborn. Am Heart J 1982;103:131-132.
  4. Sperling DR, Dorsey TJ, Rowen M, Gazzaniga AB. Percutaneous transluminal angioplasty of congenital coarctation of the aorta. Am J Cardiol 1983;51:562-564.
  5. Tynan M, Finley JP, Fontes V, et al. Balloon angioplasty for the treatment of native coarctation: results of Valvuloplasty and Angioplasty of Congenital Anomalies Registry. Am J Cardiol 1990;65:790-2.
  6. Rao PS. Current status of balloon angioplasty for neonatal and infant coarctation. Prog Pediatr Cardiol 2001;14:35-44.
  7. Hu ZP, Wang ZW, Dai XF, et al. Outcomes of surgical versus balloon angioplasty treatment for native coarctation of the aorta: a meta-analysis. Ann Vasc Surg 2014;28:394-403.
  8. Forbes TJ, Kim DW, Du W. Comparison of surgical, stent, and balloon angioplasty treatment of native coarctation of the aorta: an observational study by the CCISC. J Am Coll Cardiol 2011;58:2664-74.
  9. Ringel RE, Vincent J, Jenkins KJ, et al. Acute outcome of stent therapy for coarctation of the aorta: results of the coarctation of the aorta stent trial. Catheter Cardiovasc Interv 2013;82:503-10.
  10. Rao PS. Current status of balloon angioplasty for neonatal and infant coarctation. Prog Pediatr Cardiol 2001;14:35-44.
  11. Forbes TJ, Kim DW, Du W. Comparison of surgical, stent, and balloon angioplasty treatment of native coarctation of the aorta: an observational study by the CCISC. J Am Coll Cardiol 2011;58:2664-74.
  12. Hu ZP, Wang ZW, Dai XF, et al. Outcomes of surgical versus balloon angioplasty treatment for native coarctation of the aorta: a meta-analysis. Ann Vasc Surg 2014;28:394-403.
  13. Forbes TJ, Kim DW, Du W. Comparison of surgical, stent, and balloon angioplasty treatment of native coarctation of the aorta: an observational study by the CCISC. J Am Coll Cardiol 2011;58:2664-74.
  14. Tzifa A, Ewert P, Brzezinska-Rajszys G, et al. Covered Cheatham-platinum stents for aortic coarctation: early and intermediate-term results. J Am Coll Cardiol 2006;47:1457-63.
  15. Hijazi, ZM; Kenny, DP. Covered Stents for Coarctation of the AortaTreating the Interventionalist or the Patient? JACC Cardiovasc Interv 2014;7:424-5.
  16. Schranz D1, Zartner P, Michel-Behnke I, et al.Bioabsorbable metal stents for percutaneous treatment of critical recoarctation of the aorta in a newborn. Catheter Cardiovasc Interv 2006;67:671-3.
  17. Redington AN, Booth P, Shore DF, Rigby ML.Primary balloon dilatation of coarctation of the aorta in neonates. Br Heart J 1990;64:277-81.
  18. Fletcher SE, Nihill MR, Grifka RG, et al. Balloon angioplasty of native coarctation of the aorta: midterm follow-up and prognostic factors. J Am Coll Cardiol 1995:25:730-4.
  19. Rao PS. Current status of balloon angioplasty for neonatal and infant coarctation. Prog Pediatr Cardiol 2001;14:35-44.
  20. Patel HT, Madani A, Paris YM, et al. Balloon angioplasty of native coarctation of the aorta in infants and neonates: is it worth the hassle? Pediatr Cardiol 2001;22:53-7.

Clinical Topics: Cardiac Surgery, Congenital Heart Disease and Pediatric Cardiology, Invasive Cardiovascular Angiography and Intervention, Vascular Medicine, Aortic Surgery, Cardiac Surgery and CHD & Pediatrics, Congenital Heart Disease, CHD & Pediatrics and Interventions, Interventions and Structural Heart Disease, Interventions and Vascular Medicine

Keywords: Angioplasty, Angioplasty, Balloon, Angioplasty, Balloon, Coronary, Aorta, Aortic Aneurysm, Aortic Coarctation, Child, Incidental Findings, Infant, Infant, Newborn, Intubation, Pediatrics, Stents, Tunica Media


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