Lisa Bergersen

Adverse event rates in congenital cardiac catheterization — A multi-center experience†

Objectives: To describe case mix variation among institutions, and report adverse event rates in congenital cardiac catheterization by case type. Background: Reported adverse event rates for patients with congenital heart disease undergoing cardiac catheterization vary considerably, due to non‐comparable standards of data inclusion, and highly variable case mix. Methods: The Congenital Cardiac Catheterization Outcomes Project (C3PO) has been capturing case characteristics and adverse events (AE) for all cardiac catheterizations performed at six pediatric institutions. Validity and completeness of data were independently audited. Results: Between 2/1/07 and 4/30/08, 3855 cases (670 biopsy, 1037 diagnostic, and 2148 interventional) were recorded, median number of cases per site 480 (308 to 1526). General anesthesia was used in 70% of cases (28 to 99%), and 22% of cases (15 to 26%) were non‐electively or emergently performed. Three institutions performed a higher proportion of interventions during a case, 72 to 77% compared to 56 to 58%. The median rate of AE reported per institution was 16%, ranging from 5 to 18%. For interventional cases the median rate of AE reported per institution was 19% (7 to 25%) compared to 10% for diagnostic cases (6 to 16%). The incidence of AE was significantly higher for interventional compared to diagnostic cases (20% vs 10%, p<0.001), as was the incidence of higher severity AE (9% vs 5%, p<0.001). Adverse events in biopsy cases were uncommon. Conclusions: In this multi‐institutional cohort, the incidence of AE is higher among interventional compared to diagnostic cases, and is very low among biopsy cases. Equitable comparisons among institutions will require the development and application of risk adjustment methods.

Databases for assessing the outcomes of the treatment of patients with congenital and paediatric cardiac disease - the perspective of cardiology

This review includes a brief discussion, from the perspective of cardiac surgeons, of the rationale for creation and maintenance of multi-institutional databases of outcomes of congenital heart surgery, together with a history of the evolution of such databases, a description of the current state of the art, and a discussion of areas for improvement and future expansion of the concept. Five fundamental areas are reviewed: nomenclature, mechanism of data collection and storage, mechanisms for the evaluation and comparison of the complexity of operations and stratification of risk, mechanisms to ensure the completeness and accuracy of the data, and mechanisms for expansion of the current capabilities of databases to include comparison and sharing of data between medical subspecialties. This review briefly describes several European and North American initiatives related to databases for pediatric and congenital cardiac surgery the Congenital Database of The European Association for Cardio-Thoracic Surgery, the Congenital Database of The Society of Thoracic Surgeons, the Pediatric Cardiac Care Consortium, and the Central Cardiac Audit Database in the United Kingdom. Potential means of approaching the ultimate goal of acquisition of long-term follow-up data, and input of this data over the life of the patient, are also considered.

Catheterization for Congenital Heart Disease Adjustment for Risk Method (CHARM)

OBJECTIVES This study sought to develop a method to adjust for case mix complexity in catheterization for congenital heart disease to allow equitable comparisons of adverse event (AE) rates. BACKGROUND The C3PO (Congenital Cardiac Catheterization Project on Outcomes) has been prospectively collecting data using a Web-based data entry tool on all catheterization cases at 8 pediatric institutions since 2007. METHODS A multivariable logistic regression model with high-severity AE outcome was built using a random sample of 75% of cases in the multicenter cohort; the models were assessed in the remaining 25%. Model discrimination was assessed by the C-statistic and calibration with Hosmer-Lemeshow test. The final models were used to calculate standardized AE ratios. RESULTS Between August 2007 and December 2009, 9,362 cases were recorded at 8 pediatric institutions of which high-severity events occurred in 454 cases (5%). Assessment of empirical data yielded 4 independent indicators of hemodynamic vulnerability. Final multivariable models included procedure type risk category (odds ratios [OR] for category: 2 = 2.4, 3 = 4.9, 4 = 7.6, all p < 0.001), number of hemodynamic indicators (OR for 1 indicator = 1.5, ≥2 = 1.8, p = 0.005 and p < 0.001), and age <1 year (OR: 1.3, p = 0.04), C-statistic 0.737, and Hosmer-Lemeshow test p = 0.74. Models performed well in the validation dataset, C-statistic 0.734. Institutional event rates ranged from 1.91% to 7.37% and standardized AE ratios ranged from 0.61 to 1.41. CONCLUSIONS Using CHARM (Catheterization for Congenital Heart Disease Adjustment for Risk Method) to adjust for case mix complexity should allow comparisons of AE among institutions performing catheterization for congenital heart disease.

Transcatheter Device Closure of Atrial Septal Defects: A Safety Review

This review discusses the current safety issues related to U.S. Food and Drug Administration approved atrial septal defect devices and proposes a potential avenue to gather additional safety data including factors, which may be involved in device erosion.

Procedure-Type Risk Categories for Pediatric and Congenital Cardiac Catheterization

Background— The Congenital Cardiac Catheterization Project on Outcomes (C3PO) was established to develop outcome assessment methods for pediatric catheterization. Methods and Results— Six sites have been recording demographic, procedural and immediate outcome data on all cases, using a web-based system since February 2007. A sample of data was independently audited for validity and data completeness. In 2006, participants categorized 84 procedure types into 6 categories by anticipated risk of an adverse event (AE). Consensus and empirical methods were used to determine final procedure risk categories, based on the outcomes: any AE (level 1 to 5); AE level 3, 4, or 5; and death or life-threatening event (level 4 or 5). The final models were then evaluated for validity in a prospectively collected data set between May 2008 and December 31, 2009. Between February 2007 and April 2008, 3756 cases were recorded, 558 (14.9%) with any AE; 226 (6.0%) level 3, 4, or 5; and 73 (1.9%) level 4 or 5. General estimating equations models using 6 consensus-based risk categories were moderately predictive of AE occurrence (c-statistics: 0.644, 0.664, and 0.707). The participant panel made adjustments based on the collected empirical data supported by clinical judgment. These decisions yielded 4 procedure risk categories; the final models had improved discrimination, with c-statistics of 0.699, 0.725, and 0.765. Similar discrimination was observed in the performance data set (n=7043), with c-statistics of 0.672, 0.708, and 0.721. Conclusions— Procedure-type risk categories are associated with different complication rates in our data set and could be an important variable in risk adjustment models for pediatric catheterization.

Bloodstream Infections Occurring in Patients With Percutaneously Implanted Bioprosthetic Pulmonary Valve A Single-center Experience

Background—Percutaneous pulmonary valve implantation using a stent-based bioprosthetic valve provides an alternative to surgery in select patients. Systemic infections in Melody valve–implanted patients with and without identified valve involvement have been reported, yet the incidence is unknown, and risk factors remain unidentified. Methods and Results—Between 2007 and 2012, a total of 147 consecutive patients with congenital heart disease underwent Melody percutaneous pulmonary valve implantation at our institution. Demographic and clinical variables were collected at baseline and at follow-up and analyzed as predictors. The occurrence of bloodstream infection (BSI), defined as a bacterial infection treated with ≥4 weeks of antibiotics, served as our primary outcome. The mean age at implantation for the study population was 21.5±11 years, and tetralogy of Fallot was the cardiac condition in 59%. During a median follow-up of 19 months, 14 patients experienced BSI (9.5%; 95% confidence interval, 5.3%–15%). Of these, 4 (2.7%) patients had Melody valve endocarditis. Two patients died during the event, neither of whom had known valve involvement. The median procedure to infection time was 15 months (range, 1–56). In univariate analysis, male sex, previous endocarditis, in situ stents in the right ventricular outflow tract, and presence of outflow tract irregularities at the implant site were associated with BSI occurrence. Conclusions—In this cohort, 9.5% of patients who underwent Melody percutaneous pulmonary valve implantation experienced subsequent BSI, occurring 1 to 56 months after implant, and 2.7% of patients had prosthetic endocarditis. Our findings suggest that patient and nonvalve anatomic factors may be associated with BSI after percutaneous pulmonary valve implantation.

Anti-CD 18 monoclonal antibody slows experimental aortic aneurysm expansion☆☆☆★★★

PURPOSE Inflammation has been implicated as a contributing factor in the expansion of abdominal aortic aneurysms (AAA). To test this hypothesis, we examined the effects of a monoclonal antibody (MAB) to the leukocyte CD18 adhesion molecule on the expansion of experimental AAA. METHODS Aneurysms were induced by perfusion of an isolated segment of the infrarenal aorta with elastase in 22 normotensive (WKY) and 17 genetically hypertensive (WKHT) rats. Animals of both strains were randomly allocated to control or MAB-treated groups (MAB, 5 microgram/100 gm body weight intraperitoneally, daily, beginning on the operative day for a total of four doses). The activity of the MAB against rat leukocytes had first been determined by in vitro immunofluorescence flow cytometry. Aortic size was directly measured initially and on day 14. At that time, a segment of aorta was stained with hematoxylin and eosin and mononuclear leukocytes and neutrophils were counted in each of 10 microscopic fields (400X). RESULTS The initial aortic size in all animals was 1.11+/-0.15 mm. All groups developed aneurysms significantly larger than the initial aortic size (p<0.01). However, the MAB-treated animals had significantly smaller aneurysms than the untreated controls (mm): WKY: 3.63+/-1.26, WKY-MAB: 2.08+/-0.30, WKHT: 4.54+/-1.86, WKHT-MAB: 2.37+/-0.40, p<0.0001. There also were significantly fewer monocytes in the MAB-treated normotensive rats: WKY:35.5+/-29.9, WKHT:40.6+/-28.8, WKY-MAB: 8.9+/-8.5, WKHT-MAB: 32.3+/-25.7, p=0.03. Neutrophil counts did not differ significantly between the groups. CONCLUSIONS Treatment with anti-CD18 monoclonal antibody slows the expansion of AAA in this experimental model. The associated inflammatory process at day 14, as indicated by monocyte infiltration, is reduced, but this effect may be opposed by the presence of hypertension. Further evaluation of the role of leukocytes and adhesion molecules in the expansion of AAA is warranted.

Adverse Event Rates in Congenital Cardiac Catheterization: A New Understanding of Risks

We sought to characterize the frequency, severity, and attributability of adverse events (AE) in congenital cardiac catheterization and identify patient and procedural characteristics associated with AE. Risk for any AE was associated with age < 1 year (odds ratio [OR] 2.3), interventional cases (OR 2.2), increasing procedure type risk group (OR 1, 2.0, 2.5), and indicator of hemodynamic vulnerability (OR 1.6), all p < 0.001. Each of these and weight were also associated with increased risk for high severity events, except for young age. Our understanding of populations at risk for adverse outcomes in congenital cardiac catheterization cases can be enhanced through the development and refinement of variables that categorize procedure types and patient characteristics by similar risk for adverse outcomes.

Characterization of radiation exposure and effect of a radiation monitoring policy in a large volume pediatric cardiac catheterization lab

Objectives: This study aimed to characterize radiation dose during cardiac catheterization in congenital heart disease and to assess changes in dose after the introduction of a radiation monitoring policy. Background: Minimizing radiation exposure is an important patient safety initiative and relatively few data are available characterizing radiation dose for the broad spectrum of congenital cardiac catheter‐based interventions. Methods: Radiation dose data were reviewed on all cases since 7/1/05 at a single large center. Procedures were classified according to 20 common case types then subdivided into five age categories. Groups with <20 cases were excluded. Radiation dose was estimated by cumulative air KERMA (mGy) and DAP (dose area product, μGym2) which were reported as median and interquartile range (IQR). We also examined differences in radiation dose before and after the implementation of a radiation policy. Results: Between 7/1/05 and 12/10/08, 3,365 cases were identified for inclusion. Radiation dose increased with age and procedural complexity. Patients were characterized into low, medium, and high dose categories relative to each other. “Low” dose cases included isolated pulmonary or aortic valvotomy, pre‐Fontan assessment, and ASD closure. “High” dose cases involved multiple procedures in pulmonary arteries or veins. After introduction of a radiation policy, there was a significant decrease in radiation dose across a variety of case types, particularly among infants and young children. Conclusions: Radiation dose in congenital cardiac catheterization varies by age and procedure type. A radiation monitoring and notification policy may have contributed to reduced radiation dose.

Ventricular Function Deteriorates With Recurrent Coarctation in Hypoplastic Left Heart Syndrome

BACKGROUND Recurrent coarctation (re-CoA) after stage I palliation in hypoplastic left heart syndrome (HLHS) is deleterious. We studied whether re-CoA had an effect on ventricular systolic function. METHODS Retrospectively reviewed were HLHS patients surviving stage I Norwood palliation (stage I) and cavopulmonary shunt (CPS) between January 2004 and February 2007. Echocardiographic right ventricular fractional area change (RV-FAC) was used to evaluate ventricular systolic function after stage I, before CPS, and before Fontan procedures. Cardiac catheterization and magnetic resonance imaging data before CPS were reviewed to assess re-CoA, using a coarctation index (CI = isthmus diameter/descending aortic diameter). RESULTS Fifty-one patients were included, and 21 had a CI of less than 0.75 (mean, 0.82 +/- 0.19; 21). Twelve patients required arch balloon dilation between CPS and Fontan. The change of RV-FAC for all patients between stage I and CPS was -2.2% +/- 9.6%. Pearson correlation coefficient demonstrated a significant correlation between lower CI values and lower RV-FAC at the pre-CPS echocardiogram (r = .35, p = 0.03); and lower CI values and greater decrease in RV-FAC between stage I and pre-CPS evaluation (r = 0.40, p = 0.018). At follow-up pre-Fontan, RV-FAC for patients who underwent balloon dilation for re-CoA recovered to a level that was inferior but not significantly different from that of patients who did not need balloon dilation. CONCLUSIONS Recurrent aortic arch obstruction after stage I for HLHS is associated with worse RV systolic function at the time of stage II operation. Timely intervention on the re-CoA results in recovery of RV function.