Analysis of immortal-time effect in post-infarction ventricular septal defect.

Introduction: Time-fixed analyses have traditionally been utilized to examine outcomes in post-infarction ventricular septal defect (VSD). The aims of this study were to: (1) analyze the relationship between VSD closure/non-closure and mortality; (2) assess the presence of immortal-time bias. Material and methods: In this retrospective cohort study, patients with ST-elevation myocardial infarction (STEMI) complicated by VSD. Time-fixed and time-dependent Cox regression methodologies were employed. Results: The study included 80 patients: surgical closure (n = 26), transcatheter closure (n = 20), or conservative management alone (n = 34). At presentation, patients without VSD closure exhibited high-risk clinical characteristics, had the shortest median time intervals from STEMI onset to VSD development (4.0, 4.0, and 2.0 days, respectively; P = 0.03) and from STEMI symptom onset to hospital arrival (6.0, 5.0, and 0.8 days, respectively; P < 0.0001). The median time from STEMI onset to closure was 22.0 days (P = 0.14). In-hospital mortality rate was higher among patients who did not undergo defect closure (50%, 35%, and 88.2%, respectively; P < 0.0001). Closure of the defect using a fixed-time method was associated with lower in-hospital mortality (HR = 0.13, 95% CI 0.05-0.31, P < 0.0001, and HR 0.13, 95% CI 0.04-0.36, P < 0.0001, for surgery and transcatheter closure, respectively). However, when employing a time-varying method, this association was not observed (HR = 0.95, 95% CI 0.45-1.98, P = 0.90, and HR 0.88, 95% CI 0.41-1.87, P = 0.74, for surgery and transcatheter closure, respectively). These findings suggest the presence of an immortal-time bias. Conclusions: This study highlights that using a fixed-time analytic approach in post-infarction VSD can result in immortal-time bias. Researchers should consider employing time-dependent methodologies.

Optimización de la protección en radiología y cardiología intervencionista pediatrica en América Latina y el Caribe (OPRIPALC) / Optimization of protection in pediatric interventional cardiology and radiology in Latin America and the Caribbean (OPRIPALC)

El objetivo del presente artículo ha sido describir el programa "Optimización de la Protección en Radiología Intervencionista Pediátrica en América Latina y el Caribe" (OPRIPALC) que nace el año 2018 como respuesta conjunta de la Organización Panamericana de la Salud y la Organización Mundial de la Salud, en cooperación con el Organismo Internacional de Energía Atómica, para colaborar con sus Estados miembros en asegurar que las exposiciones a la radiación de los pacientes pediátricos sean las mínimas necesarias durante los procedimientos intervencionistas. Actualmente, hay 18 centros de los siguientes 10 países que participan: Argentina, Brasil, Chile, Colombia, Costa Rica, Cuba, Ecuador, México, Perú y Uruguay. Para el desarrollo del programa se plantean una serie de objetivos, productos, actividades y resultados esperados. La puesta en marcha de la WEB de OPRIPALC ha significado un instrumento muy válido para seguir la información actualizada del programa. Un programa actualizado de formación en radioprotección para los profesionales implicados en el programa, se está realizando por medio de "webinars". Se deberá seguir actuando en la aplicación del programa de control de calidad básico para los equipos de rayos X participantes y validar los valores de los Niveles de Referencia para Diagnóstico (NRDs). Se propone formar un equipo de trabajo entre los Físicos Médicos y Tecnólogos Médicos participantes de OPRIPALC para implicarse en las pruebas de control básicas que todos los centros debieran realizar. Se han presentado algunos resultados iniciales de OPRIPALC en eventos científicos internacionales. Se está avanzando en proponer unos primeros valores sobre NRDs en procedimientos de intervencionismo cardiológico pediátrico por bandas de edad y peso. OPRIPALC es una de las pocas iniciativas de carácter regional para obtener valores de NRDs en procedimientos intervencionistas pediátricos. Se espera que tanto los valores de referencia como la metodología empleada en OPRIPALC, puedan ser utilizados en otras regiones del mundo.

The objective of this article has been to describe the program "Optimization of Protection in Pediatric Interventional Radiology in Latin America and the Caribbean" (OPRIPALC) that was born in 2018 as a joint response of the Pan American Health Organization and the World Organization of the Health, in cooperation with the International Atomic Energy Agency, to collaborate with its member states in ensuring that radiation exposures of pediatric patients are the minimum necessary during interventional procedures. Currently, there are 18 centers from the following 10 countries participating: Argentina, Brazil, Chile, Colombia, Costa Rica, Cuba, Ecuador, Mexico, Peru and Uruguay. For the development of the program, a series of objectives, products, activities and expected results are proposed. The launch of the OPRIPALC WEBSITE has been a very valid instrument for following up-to-date information on the program. An updated training program in radiation protection for the professionals involved in the program is being carried out through webinars. It should continue acting in the application of the basic quality control program for the participating X-ray equipment and validate the values of the Diagnostic Reference Levels (DRLs). It is proposed to form a work team among the OPRIPALC participating medical physicists to get involved in the basic control tests that all centers should carry out. Some initial results of OPRIPALC have been presented at international scientific events. Progress is being made in proposing first values on DRLs in pediatric cardiac intervention procedures by age and weight bands. OPRIPALC is one of the few regional initiatives to obtain DRLs values in pediatric interventional procedures. It is expected that both the reference values and the methodology used in OPRIPALC can be used in other regions of the world.

Balloon Angioplasty for Native Aortic Coarctation in 3- to 12-Month-Old Infants.

BACKGROUND: Balloon angioplasty for native coarctation of the aorta (CoA) is successful in children and adults but in neonates results in frequent restenosis. The efficacy of balloon angioplasty for native CoA during infancy beyond the neonatal period was examined in infants aged 3 to 12 months of age. METHODS: A retrospective review of 68 infants who underwent balloon angioplasty for native CoA. 95% CI are in parentheses. RESULTS: Procedural age was (mean±SD) 6±3.4 months and weight was 7±1.8 kg. Balloon angioplasty produced a large decrease in both the noninvasive arm-to-leg blood pressure gradient (41.2±18.7 to 5.6±9.6 mm Hg) and the invasive peak systolic pressure gradient (34±12 to 11±9 mm Hg). Balloon angioplasty increased the CoA diameter from 2.7±1 mm to 4.6±1.2 mm. One patient was lost to follow-up. A catheter reintervention was required in 11.8% and surgery in 10.3%. The hazard of reintervention was highest early. Median freedom from reintervention was 89% (95% CI, 80%-96%) at 1 year, 83% (95% CI, 73%-92%) at 5 years, and 81% (95% CI, 69%-90%) at 10 years. Femoral artery thrombosis was documented in 6 (9%) infants without any long-term consequence. One patient developed a small aortic aneurysm late and has not required treatment. A robust estimate of the frequency of aortic aneurysms remains to be determined as the majority of subjects have not had cross-sectional imaging. CONCLUSIONS: Balloon angioplasty of native CoA is effective and safe in infants aged 3 to 12 months with outcomes comparable to those in older children and adults. Catheter reinterventions can avoid the need for surgery in most patients.

Use of Amplatzer vascular plugs and Amplatzer duct occluder II additional sizes for occlusion of patent ductus arteriosus: A multi-institutional study.

BACKGROUND: Variable patent ductus arteriosus (PDA) morphology and the need to close PDAs in small size patients has led physicians to use Amplatzer Vascular Plugs (AVP) and recently available Amplatzer Duct Occluder II - Additional Sizes (ADO II AS). The purpose of this study was to analyze the safety, efficacy, and complication rates of the ADO II AS and AVPs, specifically AVP II. METHODS: All patients undergoing PDA closure with an AVP or ADO II AS from 2011 to 2016 were included. Clinical, echocardiographic, and angiographic data were collected and reviewed. RESULTS: Four hundred and sixty-nine patients were included. Median age was 27 months (0.75-852) and the median weight was 11.4 kg (1-92). There were 51 patients ≤5 kg. Type A PDA was most common in 48% (n = 225), followed by type E (27.5%, n = 129), type D (13%, n = 61), type C (10.2%, n = 48), and type B (1.3%, n = 6). Devices included AVP II (n = 421), ADO II AS (n = 30), and AVP IV (n = 18), left pulmonary artery stenosis occurred in 4.3% (n = 20). One patient required surgery for severe stenosis; the remaining cases were mild and required no intervention. Device embolization occurred in 3 patients (10%) with the ADO II AS. Successful device closure was achieved in 98.9% of cases. CONCLUSIONS: The AVP II was highly effective for closing PDAs in smaller babies with varying morphologies and is safe when used in small sized patients with relatively low risk of complications. More studies are warranted to clarify the risks of ADO II AS.

Outcomes of Delayed Sternal Closure in Pediatric Heart Surgery: Single-Center Experience.

BACKGROUND: Delayed sternal closure (DSC) after cardiac surgery is a therapeutic option in the treatment of the severely impaired heart in pediatric cardiac surgery. METHODS: A single-center retrospective review of all bypass surgeries performed over a 10-year period (2003-2012). RESULTS: Of a total of 2325 patients registered in our database, the DSC group included 259 cases (11%), and the remaining 2066 cases (89%) constituted the control group (PSC). RACHS-1 risk was higher for the DSC group (74% had a score of 3 or 4) than for the PSC group (82% had a score of 2 or 3). The most frequent diagnosis for the DSC group was transposition of the great arteries (28%). We found out that hemodynamic instability was the main indication observed in patients aged ≤ 8 years (63%), while bleeding was the principal indication for patients aged ≥ 8 years (94%) (p ≤ 0.001). The average time between surgery and sternal closure was 2.3 ± 1.4 days. Overall mortality rates were higher for patients of the DSC group (22%) than for the PSC group (8.7%) (OR: 0.4 (95% CI: 0.4 to 0.5), p < 0.05). There were six patients with DSC who developed mediastinitis (2.3%). The risk of mediastinitis was significantly higher when DSC was performed 4 days after the primary surgery. CONCLUSIONS: DSC is an important management strategy for congenital cardiac surgery in infants and children. The prolonged sternal closure time is associated with an increased rate of postoperative mediastinitis.

Catheter-Based Palliation in an Infant With Obstructed Cor Triatriatum.

A 33-day-old infant with obstructed cor triatriatum sinister and partial anomalous pulmonary venous drainage presented with respiratory distress and fever. Her suprasystemic pulmonary hypertension was relieved by opening the connection to the right atrium using balloon atrial septoplasty and septostomy, and to the inferior chamber using balloon dilation of a fenestration in the dividing membrane. This enabled extubation and discharge, with elective surgical repair at 2 months. To our knowledge, this is the youngest patient to receive a catheter intervention for obstructed cor triatriatum sinister, providing relief of pulmonary hypertension and postponement of surgical repair.

Fontan Procedure at 2,240 m Above Sea Level.

The modified Fontan procedure represents the final stage of reconstructive surgery for most patients with functionally univentricular hearts. Although outcomes following Fontan procedures performed at sea level are widely reported, less has been documented and reported concerning outcomes in regions at high altitude. To clarify the main features involved, we present our institutional experience with Fontan operations performed in Mexico city (2,240 m above the sea level), with an emphasis on historical evolution of treatment. A retrospective and observational study was undertaken, which included 98 patients over a period of 18 years, and clinical outcomes in terms of morbidity and mortality were analyzed. A change in operative technique from intra-cardiac nonfenestrated Fontan procedure to extra-cardiac fenestrated technique occurred in 2001. Early mortality rates before and after this change in surgical approach were 26% and 4.7%, respectively. The most common morbidity was the occurrence of pleural effusions (98% of patients), which also appears to be a risk factor for operative mortality. Much remains unknown about the pathophysiology of the Fontan circulation at high altitude, and we need to develop morphological study protocols that include pulmonary biopsy to increase our knowledge and inform our therapeutic actions.