Long-term outcome of sirolimus-eluting stent implantation for left main coronary artery stenosis in infancy

OCT: A Modality for Identifying Stent Failure in Pediatric Patients With Angiographically Silent Coronary Arteries

We present the case of a 16-year-old patient with anomalous left coronary artery from the left pulmonary artery requiring percutaneous coronary intervention in infancy who presented with ventricular fibrillation arrest. A coronary angiogram revealed 40% narrowing of the stent relative to the remainder of the left main coronary artery. Optical coherence tomography was performed and revealed an area stenosis of 70% relative to the native left main coronary artery. The patient had outgrown the stent. (Level of Difficulty: Advanced.)

Successful everolimus-eluting stent implantation into the left main trunk stenosis in the anomalous coronary artery after neo-aortic valve replacement in a 6-year-old boy

CHDs occasionally have coronary complications; however, stent implantation is technically difficult in small children. We reported a successful drug-eluting stent implantation into the congenital anomalous coronary artery in a 6-year-old boy. This treatment is useful for rescuing coronary stenosis, and dual antiplatelet therapy is important to prevent stent restenosis.

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.

Pharmacokinetics of Sirolimus-Eluting Stents Implanted in the Neonatal Arterial Duct

Background—

Sirolimus-eluting stents may have clinical advantages over bare-metal stents in the extremely proliferative environment of the neonatal arterial duct. However, sirolimus has immunosuppressive actions and little is known regarding sirolimus pharmacokinetics in the newborn.

Methods and Results—

This is a retrospective review of sirolimus pharmacokinetics in neonates who underwent sirolimus-eluting stent implantation in the arterial duct for pulmonary blood flow augmentation. Pharmacokinetic parameters were obtained by noncompartmental analysis and by a Bayesian one-compartment nonlinear mixed model. Nine neonates received a single sirolimus-eluting stent with a total sirolimus dose of 245 μg (n=1), 194 μg (n=5), or 143 μg (n=3). Peak sirolimus concentrations were 13.6±4.5 μg/L (24.8 μg/L highest) and clearance was 0.042±0.03 L/hour (noncompartmental analysis) and 0.051 L/hour (95% credible intervals 0.037–0.069, nonlinear mixed model). Sirolimus remained >5 μg/L, the trough level used in oral immunosuppressive therapy, for (95% credible interval) 15.9 (11.4, 22.8), 12.9 (7.6, 19.0), and 8.4 (2.3, 14.5) days for the 245, 194, and 143 μg sirolimus dose stents, respectively. Estimates of the duration of systemic immunosuppression are provided for combinations of 2 stents.

Conclusions—

In neonates after sirolimus-eluting stent implantation, peak sirolimus levels were 20× higher and clearance 30× lower than previously reported in older children and adults. Sirolimus levels were within the immunosuppressive range for a prolonged period, but with no observable clinically significant adverse outcomes.