Stephanie L. Siehr

Home monitoring program reduces interstage mortality after the modified Norwood procedure

BACKGROUND From 2002 to 2005, the interstage mortality after a modified Norwood procedure was 7% in our program. An interstage home monitoring program (HMP) was established to identify Norwood procedure patients at increased risk of decompensation and to reduce interstage mortality. METHODS Results of the first 5 years of the Norwood HMP were reviewed retrospectively. Interstage was defined as the time between Norwood hospital discharge and admission for second stage surgical palliation. In the HMP, families documented oxygen saturation, heart rate, weight, and feedings daily. Nurse practitioners called each family at least weekly, and when issues arose, action plans were determined based on symptom severity. RESULTS Between October 2005 and October 2010 there were 46 Norwood procedure patients who survived to hospital discharge. All were enrolled in the HMP. Forty-five patients had a Norwood procedure with right ventricle to pulmonary artery conduit, and 1 patient had a modified Blalock-Taussig shunt. Interstage survival was 100%. Nineteen patients (41%) were admitted interstage; 5 patients were admitted twice, 1 patient was admitted 4 times. Seventeen patients (37%) required interstage interventions. Eight patients (17%) required major interventions: conduit stenting, aortic arch balloon angioplasty, emergent shunt, or early Glenn surgery. Minor interventions included supplemental oxygen, blood transfusion, intravenous hydration, diuresis, anti-arrhythmic therapy, or feeding adjustments. CONCLUSIONS In the first 5 years of the HMP, all infants discharged after a modified Norwood procedure survived the interstage period. The HMP altered clinical management in 37% of patients. Home monitoring of oxygen saturation, heart rate, weight, and feedings, along with comprehensive care coordination, allowed timely interventions and reduced interstage mortality from 7% to 0%.

Children with pulmonary arterial hypertension and prostanoid therapy: Long-term hemodynamics

BACKGROUND Pediatric patients with severe pulmonary arterial hypertension (PAH) are treated with intravenous epoprostenol or intravenous or subcutaneous treprostinil. Little is known about longitudinal hemodynamics and outcomes of epoprostenol, treprostinil, and transitions from epoprostenol to treprostinil. METHODS This was retrospective study of 77 pediatric patients (47 idiopathic PAH, 24 congenital heart disease-PAH) receiving epoprostenol or treprostinil from 1992 to 2010 at 2 centers. Outcomes were defined as living vs dead/transplant. RESULTS Mean age at baseline was 7.7 ± 5.2 years, with follow-up of 4.3 ± 3.4 years. Thirty-seven patients were treated with epoprostenol, 20 with treprostinil, and 20 were transitioned from epoprostenol to treprostinil. Mean pulmonary-to-systemic vascular resistance ratio (Rp/Rs) for epoprostenol was 1.0 ± 0.4, 0.8 ± 0.4, 0.8 ± 0.4, 1.0 ± 0.4, and 1.2 ± 0.4, respectively, at baseline, 1, 2, 3, and 4 years. For treprostinil, Rp/Rs was 0.9 ± 0.3, 0.7 ± 0.3, 0.5 ± 0.2, (p < 0.01 vs baseline), and 1.1 ± 0.2, respectively, at baseline, 1, 2, and 3 to 4 years, respectively. There were similar changes in mean pulmonary artery pressure and pulmonary vascular resistance index. The Rp/Rs 1 year after epoprostenol to treprostinil transition increased from 0.6 to 0.8 (n = 7). Changes not statistically significant unless noted. Eight patients died or received a transplant within 2 years of baseline; compared with the rest of the cohort, mean baseline Rp/Rs, right atrial pressure, and pulmonary vascular resistance index were significantly worse in this group. Thirty-nine patients remain on prostanoids, 17 are off, 16 died, and 5 received heart-lung transplant. Kaplan-Meier 5-year transplant-free survival was 70% (95% confidence interval, 56%-80%). CONCLUSION There was improvement in Rp/Rs on both therapies at 1 to 2 years that was not sustained. The 5-year transplant-free survival was better than in similar adult studies.

COCATS 4: Securing the Future of Cardiovascular Medicine.

The latest iteration of the Core Cardiology Training Statement (COCATS 4) [Corrected] provides a potentially transformative advancement in cardiovascular fellowship training intended, ultimately, to improve patient care. This review addressed 3 primary themes of COCATS 4 from the perspective of fellows-in-training: 1) the evolution of training requirements culminating in a competency-based curriculum; 2) the development of novel learning paradigms; and 3) the establishment of task forces in emerging areas of multimodality imaging and critical care cardiology. This document also examined several important challenges presented by COCATS 4. The proposed changes in COCATS 4 should not only enhance the training experience but also improve trainee satisfaction. Because it embraces continual transformation of training requirements to meet evolving clinical needs and public expectations, COCATS 4 will enrich the cardiovascular fellowship training experience for patients, programs, and fellows-in-training.

Incidence and risk factors of complete atrioventricular block after operative ventricular septal defect repair.

BACKGROUND Complete atrioventricular block (AVB) is a recognized complication of ventricular septal defect (VSD) repair. The objective of this study was to examine incidence and risk factors. METHODS This is a single-center, retrospective study. All pediatric patients (age <18 years) who underwent VSD repair between November 2001 and August 2009 with concordant atrioventricular and ventriculoarterial connections were included. Patients were classified as having no AVB or transient AVB, and outcomes of early pacemaker placement (before hospital discharge) or late pacemaker placement (after hospital discharge) were recorded. RESULTS Eight hundred twenty-eight patients (48.6% female) underwent VSD repair during the study period. Mean age at repair was 14 ± 29.4 months. A total of 64 patients (7.7%) developed surgical AVB. Among those patients who developed AVB, 48 (75%) had transient AVB. Sixteen patients (1.9%) required a pacemaker, 14 early (88%) and 2 late (12%). Patients <4 kg (4.2% vs. 1%, P ≤ .01) and those with inlet VSDs (11.6% vs. 1.4%, P ≤ .01) were more likely to develop surgical AVB. Surgical AVB was not influenced by the presence of chromosomal abnormalities or other congenital heart disease. CONCLUSION The overall incidence of surgical AVB is consistent with previous reports. Weight <4 kg and presence of an inlet VSD were significant risk factors.

Mitral Stenosis and Aortic Atresia--A Risk Factor for Mortality After the Modified Norwood Operation in Hypoplastic Left Heart Syndrome.

BACKGROUND There are conflicting reports regarding the importance of mitral stenosis and aortic atresia as a risk factor for Norwood mortality. This study reviews outcomes of this anatomic subgroup at our institution and examines the utility of preoperative cardiac catheterization and its correlation with clinical outcomes and pathology findings. METHODS This is a single-center, retrospective review of hypoplastic left heart syndrome patients who underwent modified Norwood operation between October 2005 and May 2013. RESULTS Fourteen of 74 hypoplastic left heart syndrome patients (19%) had mitral stenosis and aortic atresia. Operative mortality for MS/AA was 29% versus 7% for all other hypoplastic left heart syndrome anatomic subgroups (p = 0.04). Although only 19% of the entire cohort, the mitral stenosis and aortic atresia subgroup constituted 50% of the total operative mortality and the only interstage deaths. Autopsies support myocardial ischemia as the mechanism of death. Although preoperative angiography defined the presence of ventriculo-coronary connections, it did not clearly risk stratify patients in regard to operative mortality. CONCLUSIONS Mitral stenosis and aortic atresia is a risk factor for perioperative myocardial ischemia and mortality. Further exploration of myocardial reserve is warranted.

Hemodynamic Effects of Phenylephrine, Vasopressin, and Epinephrine in Children With Pulmonary Hypertension: A Pilot Study.

Objectives: During a pulmonary hypertensive crisis, the marked increase in pulmonary vascular resistance can result in acute right ventricular failure and death. Currently, there are no therapeutic guidelines for managing an acute crisis. This pilot study examined the hemodynamic effects of phenylephrine, arginine vasopressin, and epinephrine in pediatric patients with pulmonary hypertension. Design: In this prospective, open-label, nonrandomized pilot study, we enrolled pediatric patients previously diagnosed with pulmonary hypertensive who were scheduled electively for cardiac catheterization. Primary outcome was a change in the ratio of pulmonary-to-systemic vascular resistance. Baseline hemodynamic data were collected before and after the study drug was administered. Patients: Eleven of 15 participants were women, median age was 9.2 years (range, 1.7–14.9 yr), and median weight was 26.8 kg (range, 8.5–55.2 kg). Baseline mean pulmonary artery pressure was 49 ± 19 mm Hg, and mean indexed pulmonary vascular resistance was 10 ± 5.4 Wood units. Etiology of pulmonary hypertensive varied, and all were on systemic pulmonary hypertensive medications. Interventions: Patients 1–5 received phenylephrine 1 &mgr;g/kg; patients 6–10 received arginine vasopressin 0.03 U/kg; and patients 11–15 received epinephrine 1 &mgr;g/kg. Hemodynamics was measured continuously for up to 10 minutes following study drug administration. Measurements and Main Results: After study drug administration, the ratio of pulmonary-to-systemic vascular resistance decreased in three of five patients receiving phenylephrine, five of five patients receiving arginine vasopressin, and three of five patients receiving epinephrine. Although all three medications resulted in an increase in aortic pressure, only arginine vasopressin consistently resulted in a decrease in the ratio of systolic pulmonary artery-to-aortic pressure. Conclusions: This prospective pilot study of phenylephrine, arginine vasopressin, and epinephrine in pediatric patients with pulmonary hypertensive showed an increase in aortic pressure with all drugs although only vasopressin resulted in a consistent decrease in the ratio of pulmonary-to-systemic vascular resistance. Studies with more subjects are warranted to define optimal dosing strategies of these medications in an acute pulmonary hypertensive crisis.

Reported sildenafil side effects in pediatric pulmonary hypertension patients

Background: Sildenafil, a phosphodiestase type 5 inhibitor, was approved in 2005 for the treatment of pulmonary arterial hypertension (PAH) in adults and is commonly used off-label for pediatric patients. Little is known, however, about sildenafil’s side effects in this population. Methods: Single institution, longitudinal survey-based study performed in an outpatient pediatric cardiology clinic. Pediatric patients on sildenafil [alone or in combination with other pulmonary hypertension (PH) therapies] completed questionnaires regarding frequency of vascular, gastrointestinal, neurologic, and hematologic side effects. Results: Between January 2011 and May 2014, 66 pediatric patients with PH on sildenafil filled out 214 surveys, 32 patients (96 surveys) on monotherapy, and 43 patients (118 surveys) on sildenafil plus an endothelin receptor antagonist (ERA) (bosentan or ambrisentan) and/or a prostacyclin (epoprostenol or treprostinil). Overall, 30% of respondents identified at least one side effect. For all patients on sildenafil, incidence of side effects by system was 37% gastrointestinal, 35% vascular, and 22% neurologic. For patients on sildenafil monotherapy, incidence of side effects by system was 24% gastrointestinal, 21% vascular, and 18% neurologic compared to patients on combination therapy who reported an incidence of 48% gastrointestinal, 45% vascular, and 25% neurologic. Conclusion: Incidence of vascular, gastrointestinal, and neurologic side effect in pediatric patients on sildenafil therapy for PAH was 30%. Side effects were more common in patients on combination therapy with an ERA and/or prostacyclin than in patients on sildenafil monotherapy.

Electrical and mechanical dyssynchrony in pediatric pulmonary hypertension

BACKGROUND Electrical and mechanical dyssynchrony are often seen in patients with left ventricular failure. In pediatric pulmonary hypertension (PH), right ventricular failure predominates; however, the prevalence of electrical and/or mechanical dyssynchrony in these patients is unknown. We examined the prevalence of electrical and mechanical dyssynchrony in pediatric PH patients. METHODS Medical records (including, functional status, electrocardiograms and echocardiograms) of pediatric PH patients were reviewed. QRS duration z-scores were calculated to determine electrical dyssynchrony. Echo vector velocity imaging was used to calculate the mechanical dyssynchrony index (DI). RESULTS Seventy-seven PH patients (idiopathic pulmonary arterial hypertension [IPAH]: n = 26; congenital heart disease: n = 41; other: n = 10) were studied. Electrical dyssynchrony was seen in 84% (p < 0.01 vs historic controls), with a mean z-score of 4.3 (95% CI 3.5 to 5.1). There was no difference between those with IPAH, z = 3.6 (95% CI 2.5 to 4.6), and those without, z = 4.7 (95% CI 3.6 to 5.8). Mechanical dyssynchrony was seen in 76% of patients (mean DI = 66 ± 47 vs 18 ± 8 milliseconds in historic controls, p < 0.01) in both IPAH and non-IPAH patients. Post-operative congenital heart disease patients had the largest dyssynchrony index. No correlation was found among electrical or mechanical dyssynchrony, hemodynamics or disease severity. CONCLUSIONS Significant electrical and mechanical dyssynchrony is present in pediatric PH patients, regardless of etiology. The overall effect of electrical and mechanical dyssynchrony on outcomes in this patient population is still unknown. Select patients may benefit from resynchronization therapy.

Exploring the Role of Polycythemia in Patients With Cyanosis After Palliative Congenital Heart Surgery.

Objectives: To understand the relationship between polycythemia and clinical outcome in patients with hypoplastic left heart syndrome following the Norwood operation. Design: A retrospective, single-center cohort study. Setting: Pediatric cardiovascular ICU, university-affiliated children’s hospital. Patients: Infants with hypoplastic left heart syndrome admitted to our medical center from September 2009 to December 2012 undergoing stage 1/Norwood operation. Interventions: None. Measurements and Main Results: Baseline demographic and clinical information including first recorded postoperative hematocrit and subsequent mean, median, and nadir hematocrits during the first 72 hours postoperatively were recorded. The primary outcomes were in-hospital mortality and length of hospitalization. Thirty-two patients were included in the analysis. Patients did not differ by operative factors (cardiopulmonary bypass time and cross-clamp time) or traditional markers of severity of illness (vasoactive inotrope score, lactate, saturation, and PaO2/FIO2 ratio). Early polycythemia (hematocrit value > 49%) was associated with longer cardiovascular ICU stay (51.0 [± 38.6] vs 21.4 [± 16.2] d; p < 0.01) and total hospital length of stay (65.0 [± 46.5] vs 36.1 [± 20.0] d; p = 0.03). In a multivariable analysis, polycythemia remained independently associated with the length of hospitalization after controlling for the amount of RBC transfusion (weight, 4.36 [95% CI, 1.35–7.37]; p < 0.01). No difference in in-hospital mortality rates was detected between the two groups (17.6% vs 20%). Conclusions: Early polycythemia following the Norwood operation is associated with longer length of hospitalization even after controlling for blood cell transfusion practices. We hypothesize that polycythemia may be caused by hemoconcentration and used as an early marker of capillary leak syndrome.

Orthotopic heart transplantation in two infants with histiocytoid cardiomyopathy and left ventricular non-compaction

HC is a rare cause of congestive heart failure that typically presents with malignant ventricular arrhythmias in infants, often requiring urgent intervention. Successful heart transplantation in a patient with HC has only been reported once (J Heart Lung Transplant 2004: 23: 902). The combination of HC with concurrent LVNC has only been described three times (Int J Legal Med 2009: 123: 47; Hum Pathol 2005: 36: 403; Pediatr Dev Pathol 2012: 15: 397). We report two rare cases of HC with LVNC in two infants presenting with cardiogenic shock, one requiring ECMO support who was successfully bridged to orthotopic heart transplantation with a Berlin Heart LVAD.