Preliminary experience with IVUS in pediatric heart transplant recipients

Abstract

Post-transplant coronary artery disease (PTCAD) in children leads to late mortality and may be underdetected by coronary angiography (CA). Intravascular ultrasound (IVUS) for PTCAD surveillance has been advocated in adults, but is not routine in children. The purpose of this study was to review our initial experience with IVUS in this cohort. Procedures: Since 1/1/1998 we have performed IVUS in transplant recipients .12 y/o undergoing annual CA. Following baseline CA, IVUS was performed using a 7Fr guide catheter to place a 3.2 Fr ultrasound catheter in each coronary artery. The presence and extent of PTCAD were quantified by determining the maximal intimal thickness (MIT) and highest Stanford score (0-4) for each coronary artery examined. IVUS findings were compared with selective CA. Serial studies were compared and complications were recorded. Results: A total of 25 IVUS studies were performed in 16 pts. Age at IVUS was 18.01/-2.9yrs (12-23yrs); wt. was 59.21/-15.4kg (34-87kg); time since transplantation was 4.31/-2.3yrs (1-9yrs). (Table 1). Follow up IVUS over a 1-2 yr period was available for 10 coronaries in six pts. The Stanford score increased in 5/10 coronaries; the MIT increased in 7/10 coronaries. Complications included 1) a cardiopulmonary arrest in a 13y/o pt due to coronary air embolus during LCA IVUS; she was resuscitated and completely recovered; 2) two pts had prolonged ST elevation ($ 30 minutes) and were monitored overnight. Eight others had transient ST changes. Conclusions: IVUS is much more sensitive than CA in detecting the presence and progression of PTCAD in children. Abnormalities were detected in the majority of pts; however, IVUS may lead to additional complications. Since the clinical utility has not been demonstrated, IVUS should remain investigational in pediatric pts. Table 1