Assessing cardiac and liver iron overload in chronically transfused patients with sickle cell disease.

Transfusional iron overload represents a substantial challenge in the management of patients with sickle cell disease (SCD) who receive chronic or episodic red blood cell transfusions. Iron-induced cardiomyopathy is a leading cause of death in other chronically transfused populations but rarely seen in SCD. Study objectives were to: (i) examine the extent of myocardial and hepatic siderosis using magnetic resonance imaging (MRI) in chronically transfused SCD patients, and (ii) evaluate the relationship between long-term (over the 5 years prior to enrolment) mean serum ferritin (MSF), spot-ferritin values and liver iron content (LIC) measured using MRI and liver biopsy. Thirty-two SCD patients (median age 15 years) with transfusional iron overload were recruited from two U.S. institutions. Long-term MSF and spot-ferritin values significantly correlated with LIC by MRI-R2* (r = 0·77, P < 0·001; r = 0·82, P < 0·001, respectively). LIC by MRI-R2* had strong positive correlation with LIC by liver biopsy (r = 0·98, P < 0·001) but modest inverse correlation with cardiac MRI-T2* (r = -0·41, P = 0·02). Moderate to severe transfusional iron overload in SCD was not associated with aberrations in other measures of cardiac function based on echocardiogram or serum biomarkers. Our results suggest that SCD patients receiving chronic transfusions may not demonstrate significant cardiac iron loading irrespective of ferritin trends, LIC and erythropoiesis suppression.

Safety of Blood Pool Contrast Agent Administration in Children and Young Adults.

OBJECTIVE: The objective of our study was to determine the adverse reaction rate associated with the administration of blood pool contrast material in children and young adults. MATERIALS AND METHODS: A review of the MRI and pharmacy databases identified all patients who received gadofosveset trisodium from October 1, 2011, to June 30, 2014. Patients were classified as having been anesthetized or not anesthetized for the MRI examinations. A review of the electronic medical records identified adverse reactions recorded within 24 hours of contrast administration. The adverse reactions were graded as mild, moderate, or severe. Risk ratios were calculated between the adverse reaction rate experienced by anesthetized patients and that experience by nonanesthetized patients. RESULTS: During the study period, 626 patients (mean age, 11.7 years) received 711 doses of gadofosveset trisodium; 137 adverse reactions were recorded, which yields a 19.3% (137/711) adverse reaction rate. There were 115 adverse reactions experienced by 367 anesthetized patients (31.3%): 93.0% (107/115) were mild and 7.0% (8/115) were moderate. The remaining 22 adverse reactions were experienced by 344 (6.4%) nonanesthetized patients, and 90.9% (20/22) were mild. Three nonanesthetized patients had allergiclike reactions; of these allergiclike reactions, one was mild and two were severe for a severe allergiclike reaction rate of 0.28% (2/711). Severe allergiclike reactions were treated without any adverse outcomes. Anesthetized patients were 5.7 times more likely to experience an adverse event than nonanesthetized patients; most reactions in anesthetized patients were seen after the administration of anesthesia alone. CONCLUSION: Most reactions after gadofosveset trisodium administration in children and young adults are mild; however, severe allergiclike reactions occur, so policies must be in place to treat patients with adverse reactions when using this contrast agent. These data may be useful to centers considering administering gadofosveset trisodium to pediatric patients.

Safety and efficacy of a drug regimen to control heart rate during 64-slice ECG-gated coronary CTA in children.

BACKGROUND: The adult practice for ECG-gated single-source 64-slice coronary CTA (CCTA) includes administering beta-blockers to reduce heart rate. There are limited data on this process in children. OBJECTIVE: To evaluate the safety and efficacy of a drug regimen to decrease heart rate before performing CCTA in children. MATERIALS & METHODS: IV remifentanil and esmolol infusion were chosen to decrease heart rate in 41 children (mean age 6.5 years) while they were under general anesthesia (GA) for CCTA. Drug doses, changes in heart rate and procedural complications were recorded. CCTA image quality was graded on a scale of 1 to 5. The relationships between image quality and heart rate and image quality and age were evaluated. Patient effective radiation doses were calculated. RESULTS: Heart rates were lowered utilizing esmolol (4 children), remifentanil (2 children) or both (35 children); 26 children received nitroglycerin for coronary vasodilation. The mean decrease in heart rate was 26%. There were no major complications. The average image-quality score was 4.4. Higher heart rates were associated with worse image quality (r = 0.67, P < 0.0001). Older age was associated with better image quality (r = 0.66, P < 0.0001). Effective radiation doses were 0.7 to 7.0 mSv. CONCLUSION: Heart rate reduction for pediatric CCTA can be safely and effectively achieved while yielding high-quality images.

J. Maxwell Chamberlain Memorial Paper for congenital heart surgery. 111 Fontan conversions with arrhythmia surgery: surgical lessons and outcomes.

BACKGROUND: The evolving operative strategy and course of 111 consecutive Fontan conversions with arrhythmia surgery and pacemaker therapy were reviewed to identify risk factors for poor outcome. METHODS: Since 1994, 111 patients (mean age 22.5 +/- 7.9 years) underwent Fontan conversion with arrhythmia surgery. The series was divided into three time periods: (1) 1994 to 1996 (initial isthmus ablation, n = 9, group I); (2) 1996 to 2003 (early modified right atrial maze and Cox-maze III, n = 51, group II); and (3) 2003 to 2006 (recent modifications of the modified right atrial maze and left atrial Cox-maze III for both atrial fibrillation and left atrial reentry tachycardia, n = 51, group III). RESULTS: There were one early (0.9%) and six late deaths (5.4%); six patients required cardiac transplantation (5.4%). Two late deaths occurred after transplantation. Renal failure requiring dialysis occurred in four patients (3.6%). Mean hospital stay was 13.7 +/- 12.1 days. Mean cross-clamp time was 70.8 +/- 41.6 minutes. Four risk factors for death or transplantation were identified: presence of a right or ambiguous ventricle, preoperative protein-losing enteropathy, preoperative moderate-to-severe atrioventricular valve regurgitation, and long (>239 minutes) cardiopulmonary bypass time. In intergroup comparisons (groups I and II versus group III), three trends were noted: increased incidence of concomitant surgical repairs (p = 0.03), older patients (p = 0.01), and increased incidence of left atrial reentry tachycardia and atrial fibrillation (p = 0.04). Late recurrence of atrial tachycardia ensued in 15 of 111 (13.5%); 8 of 51 in group II (15.7%) and 4 of 51 in group III (7.8) (p = 0.3). CONCLUSIONS: Fontan conversion with arrhythmia surgery is safe and efficacious. Based on improved results and evolving surgical techniques, selection criteria can be more clearly defined.