Coronary Interventions in Congenital Heart Diseases: From Preterm to Young Adult Patients

A Rare but Real Necessity: Case Report of Coronary Artery Stenting in an Infant

Percutaneous coronary intervention (PCI) is an extremely common and well-established procedure in adults which is rarely performed in children. We present a case of a successful left main coronary artery stenting in a small infant with a congenital coronary artery anomaly. We highlight the technical challenges of performing a PCI in a small patient, the risks of antithrombotic prophylaxis in this age group, and the importance of the combined work of the adult and pediatric interventional cardiologist.

Percutaneous coronary intervention in a 4-month-old infant for stenosis of both coronary arteries after arterial switch operation for transposition of the great arteries

We present a case of percutaneous coronary intervention in a 4-month-old infant with both severe coronary stenosis and acute heart failure after arterial switch operation for transposition of the great arteries. Under extracorporeal membrane oxygenation, balloon angioplasty of the left coronary artery with a 2.0 × 15-mm balloon and stent implantation on the right coronary artery with a 2.25 × 26-mm stent were performed successfully. Echocardiography after the intervention showed recovered cardiac function and no complications.

Cangrelor use in a 6-year-old patient undergoing complex percutaneous coronary intervention after post-surgical myocardial infarction

Cangrelor is an intravenously administered P2Y₁₂ receptor antagonist, which has been approved for adult patients undergoing percutaneous coronary intervention and, due to its unique pharmacokinetics, it allows effective and controllable peri-procedural platelet inhibition. We report the case of a 6-year-old child with anomalous origin of right coronary artery from aortic left coronary sinus, who underwent elective surgical replacement of stenotic and calcified conduit between the right ventricle and the main pulmonary artery. The surgery was complicated by acute myocardial infarction secondary to coronary extrinsic compression. The patient was successfully treated with urgent percutaneous coronary intervention (simultaneous V-stenting) and cangrelor infusion, subsequently switched to clopidogrel therapy.

Percutaneous Coronary Intervention in an 8-Month-Old Infant for Ostial Stenosis of a Reimplanted Left Main Coronary Artery

Percutaneous coronary intervention (PCI) is a routine procedure undertaken in adult patients. In children, the procedure remains rare and challenging due to a multitude of factors including but not limited to complex congenital heart disease anatomy, catheter and stent to patient size mismatch, and lack of data for post-PCI antiplatelet therapy. We present a case of PCI in an 8-month-old infant with anomalous left coronary artery from pulmonary artery (ALCAPA) who developed severe ostial kinking of the left main coronary artery (LMCA) after surgical reimplantation of the anomalous coronary. A 3.5 × 8 mm Vision bare metal stent was successfully placed into the LMCA and postdilated with excellent results. Follow-up echocardiography at 6 months post-PCI demonstrated a patent stent with normal Doppler flow signals. Despite initial success, the infant developed severe heart failure and was listed for orthotopic heart transplantation at age 20 months, one year after PCI. Given the paucity of published data regarding PCI and outcomes in infants with ALCAPA after surgical reimplantation, we describe our case and present a review of the available literature.

Transcatheter Intervention of Coronary Obstructions in Infants, Children, and Young Adults

This study assesses the characteristics of coronary obstructions that underwent transcatheter intervention in a pediatric catheterization laboratory, the procedural details, and patient outcomes. Acute cardiac failure due to coronary obstructions in children is rare. The role of catheter based intervention is largely unreported. Single center retrospective review between January 2000 and December 2016. Thirty-three patients (median age 2y/o [0-38], weighing 9.6 kg [2.2-91]) underwent 39 transcatheter interventions on 39 lesions, mainly left main coronary (16/39; 39%) and right coronary (9/39; 23%) arteries. Most patients had congenital heart disease (29/33; 88%). Cath indications included ventricular dysfunction (17), cardiac arrest (7), failure to wean from cardiopulmonary bypass (5), and other (4). Almost half (18/39; 46%) were performed on ECMO support. Obstructions were post-surgical (16; 4 with coronary manipulation), thrombotic (13; 5 < 30 days from cardiac surgery), and miscellaneous lesions (10). Interventions included 25 bare metal stents implanted in 22 lesions in 17 patients (mainly post-surgical lesions; 3 at Damus-Kaye-Stansel anastomosis), nine balloon angioplasty only, four lytic therapy ± mechanical disruption of thrombus, and four technical failures. There were no procedure-related deaths. Most patients survived to discharge or transplant (24/33; 73%). Six patients who received stents had follow-up catheterization (median 15.5 months [1-106]); all were without restenosis. Most coronary obstructions intervened upon in a pediatric cath lab were on young, critically ill patients with congenital heart disease secondary to surgical manipulation/injury or thrombosis. Transcatheter intervention should be considered a potential treatment strategy in this population.

Bilayered Nanoparticles with Sequential Release of VEGF Gene and Paclitaxel for Restenosis Inhibition in Atherosclerosis

Complete reendothelialization followed by inhibition of smooth muscle cell (SMC) proliferation is considered as an effective therapeutic option to prevent restenosis. We have designed poly(lactide-co-glycolide)-loaded bilayered nanoparticles (NPs) with the ability to sequentially release vascular endothelial growth factor (VEGF)-encoding plasmids from the outer layer and paclitaxel (PTX) from the core to promote endothelial regeneration as well as prevent restenosis. Comparing with conventional NPs, which release VEGF plasmid and PTX simultaneously, we expect that the bilayered NPs could release the VEGF plasmid more rapidly, followed by a delayed release of PTX, resulting in an efficient VEGF gene transfection, which ideally could promote reendothelialization and inhibit excessive SMC growth. Indeed, in the present study, we have observed efficient gene transfection using a model plasmid as well as cell growth attenuation in vitro using Chinese hamster ovary cells. Therapeutic efficacy of the bilayered NPs on restenosis was further evaluated in vivo using a rabbit model of atherosclerosis. The bilayered NPs were administered locally via balloon angioplasty to the injured aortic wall through perfusion. Twenty-eight days after the NP administration, rabbits treated with the bilayered NPs exhibited rapid reendothelialization and inhibition of restenosis, as demonstrated by histological analysis. Increased level of VEGF and decreased level of C-reactive protein, a biological marker that is closely related to atherosclerosis, were also observed from animals treated with the bilayered NPs, implicating ameliorated atherosclerosis. Our results suggest that the VEGF plasmid-/PTX-loaded bilayered NPs exert a beneficial impact on atherosclerotic restenosis by sequentially releasing VEGF and PTX in vivo.

Percutaneous left main coronary artery stent for acute myocardial ischemia after repaired ALCAPA

Percutaneous coronary artery stent angioplasty is rare in the pediatric population but can be a life-saving by rapidly reestablishing flow to an obstructed coronary artery. It is a technically challenging and high-risk procedure in infants and further limited by the need for future surgical intervention. We report of an infant with anomalous left coronary artery from the pulmonary artery who underwent acutely successful surgical reimplantation of the left coronary artery onto the ascending aorta. One month later, she developed acute myocardial ischemia and emergent catheterization diagnosed near-total occlusion of the left coronary artery. We implanted a 2.5 mm coronary stent in the left main coronary artery with reestablishment of flow. The patient's left ventricular systolic function recovered within 4 weeks and repeat angiography 3 months later showed complete normalization of the entire left coronary artery system. The patient weighed 3 kg and was < 6 weeks of age at the time of stent implantation which to our knowledge is the smallest and youngest reported patient to undergo coronary stent angioplasty. This case supports the feasibility of this procedure in infants as a temporizing solution to hemodynamic instability from myocardial ischemia due to coronary artery stenosis. The left ventricular systolic function remained normal at 7 months after stent placement and the patient was clinically well from a cardiac perspective.

Left main coronary artery dissection in pediatric sport-related chest trauma

BACKGROUND

Traumatic coronary artery dissection (CAD) after blunt chest trauma (BCT) is extremely rare, particularly in children. Among coronary dissections, left main coronary artery (LMCA) dissection is the least common, with only two pediatric cases reported previously. Manifestations of coronary dissections can range from ST segment changes to sudden death. However, these manifestations are not specific and can be present with other cardiac injuries. To our knowledge we present the first pediatric case of traumatic LMCA dissection after sport-related BCT that was treated successfully with coronary stenting.

CASE REPORT

A 14-year-old child sustained BCT during a baseball game. Early in the clinical course, he had episodes of ventricular dysrhythmias, diffuse ST changes, rising troponin I, and hemodynamic instability. Emergent cardiac catheterization revealed an LMCA dissection with extension into the proximal left anterior descending artery (LADA). A bare metal stent was placed from the LMCA to the LADA, which improved blood flow through the area of dissection. He has had almost full recovery of myocardial function and has been managed as an outpatient with oral heart failure and antiplatelet medications. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Our case highlights that CAD, although rare, can occur after pediatric BCT. Pediatric emergency responders must have a heightened awareness that evidence of ongoing myocardial ischemia, such as evolving and focal myocardial infarction on electrocardiogram, persistent elevation or rising troponin I, and worsening cardiogenic shock, can represent a coronary event and warrant further evaluation. Cardiac catheterization can be both a diagnostic and therapeutic modality in such cases. Early recognition and management is vital for myocardial recovery.