Background
A variety of registries such as Congenital Cardiac Catheterization Project on Outcomes, Mid Atlantic Group of Interventional Cardiology, and Congenital Cardiovascular Interventional Study Consortium have reported data on outcomes of congenital cardiac catheterisation.Reference Bergersen, Marshall and Gauvreau 1 – Reference Holzer, Qureshi and Ghasemi 4 The data were frequently provided for isolated procedures such as patent ductus arteriosus, pulmonary valvuloplasty, pulmonary artery rehabilitation, atrial septal defect closure, as well as for the treatment of coarctation.Reference Holzer, Qureshi and Ghasemi 5 – Reference Holzer, Gauvreau, Kreutzer, Hirsch, Torres and Bergersen 8 Other reports focussed on a general description of the frequency of adverse events as well as risk-adjustment methods.Reference Bergersen, Gauvreau and Foerster 9 Limitations of the currently existing registries include the total number of cases submitted as well as the number of participating centres.
The IMproving Paediatric and Adult Congenital Treatment registry is now operating in over 90 hospitals and has recently reported results on selected “core” procedural categories, which were originally chosen to collect additional procedural details for future assessment of procedure-specific risk and efficacy outcomes.Reference Moore, Vincent and Beekman 10 This original selection of “core” procedures included mainly procedure types that were considered “common” and potentially amenable for the development of additional procedural outcome metrics. The publications on those “core” procedures did not include data on cases that were not captured within these “core” IMproving Paediatric and Adult Congenital Treatment procedural categories; however, these “non-core” cases account for a large number of the procedures that are performed in the catheterisation laboratory, and although many of these cases have no clearly established outcome parameters, providing basic data on these procedures could aid in this process. The purpose of this report was to describe the frequency and basic procedural characteristics of those “non-core” cases, as well as providing data on associated adverse events.
Methods
General methodology
The IMproving Paediatric and Adult Congenital Treatment registry is an initiative of the American College of Cardiology Foundation with partnering support from The Society for Cardiovascular Angiography and Interventions and the American Academy of Pediatrics, and it has been previously described by Martin et al.Reference Martin, Beekman and Ing 11 The registry collects data for use in the development of performance and quality metrics, quality improvement programmes, and peer-reviewed outcomes research focussed on paediatric and adult patients with congenital heart disease who are undergoing diagnostic catheterisations and catheter-based interventions. Demographic, clinical, procedural, and institutional data elements are collected at participating centres and entered via either a web-based platform or a software provided by ACC-certified vendors and are collected in a secure, centralised database. IMproving Paediatric and Adult Congenital Treatment registry has in place a data quality programme consistent with that described for The National Cardiovascular Data Registry.Reference Messenger, Ho and Young 12 A comprehensive description of IMproving Paediatric and Adult Congenital Treatment Registry data elements and definitions is available at http://www.ncdr.com.
Specific methodology
The focus of this study was to analyse IMproving Paediatric and Adult Congenital Treatment registry data pertaining to procedural results and outcomes in patients who undergo combined procedures or procedures that were not classified as one of the following IMproving Paediatric and Adult Congenital Treatment ‘core’ procedures originally chosen for additional data collection: atrial septal defect, device closure of patent ductus arteriosus, pulmonary valvuloplasty, aortic valvuloplasty, coarctation of the aorta angioplasty and stenting, proximal pulmonary artery stenting, and any purely diagnostic cardiac catheterisation. These isolated procedure types had been originally chosen as separate procedural categories within the IMproving Paediatric and Adult Congenital Treatment registry and results on these were previously reported by Moore et al.Reference Moore, Vincent and Beekman 10 For the purpose of this study, the above procedure types are referred to as “core” procedures. In contrast, the subjects of this study, which are all other procedures, captured within the IMproving Paediatric and Adult Congenital Treatment registry are referred to as “non-core” procedures.
Registry data from January, 2011 to June, 2013 were collected from a total of 8021 cardiac catheterisation cases. A single trip to the catheterisation laboratory was defined as a case, whereas the term “episode of care” refers to hospital admission following cardiac catheterisation, up to a maximum of 30 days after the procedure or hospital discharge, whichever occurs earlier.
Basic demographic and clinical data were provided for all the cases in this study. The entire study cohort was then separated into various case types, based on the frequency of cases performed, as well as common case characteristics. Table 1 summarises all the cases collected in this cohort, as well as the number of cases of “core” procedures performed within the same time period. Individual data of “non-core” cases were then separated into groups that had no overlap between individual case types (Table 2). Data collected for these individual case types included weight, case time, contrast administered, as well as data on adverse events and death (Fig 1).
Figure 1 Adverse events encountered in “non-core” cases.
Table 1 Frequency of procedural categories collected within the IMPACT registry.
ASD=atrial septal defect; BAS=balloon atrial septostomy; IMPACT=IMproving Paediatric and Adult Congenital Treatment; MPA=main pulmonary artery; PA=pulmonary artery; PDA=patent ductus arteriosus; PFO=patent foramen ovale; RV=right ventricle; VSD=ventricular septal defect
Case types marked with ** were “core” IMPACT case types and are not further analysed in detail within this report. This includes isolated cases of the following categories: diagnostic catheterisation, balloon pulmonary valvuloplasty, balloon aortic valvuloplasty, PDA occlusion, ASD occlusion, balloon angioplasty or stenting of coarctation, and proximal PA stenting. Percentages refer to the total number of cases in the registry (n=19,760=100%) and a case can be listed in more than one procedural category
Table 2 Case categories without overlap.
BAS=balloon atrial septostomy; MPA=main pulmonary artery; PA=pulmonary artery; PDA=patent ductus arteriosus; PFO=patent foramen ovale; PV=pulmonary vein; RV=right ventricle; VSD=ventricular septal defect
Any case is only listed in one of the case categories. Percentages refer to the total number of ‘other’ or ‘combined’ procedures (n=8021=100%)
Adverse events captured within the IMproving Paediatric and Adult Congenital Treatment registry are listed in Table 3. Major adverse events are defined as the need for permanent or temporary pacemaker, cardiac arrest, cardiac tamponade requiring pericardial drainage, embolic stroke, as well as unplanned cardiac surgery due to a catheter-related adverse event. Bleeding events after catheterisation are captured if they are associated with either a drop in haemoglobin of ⩾3 mg/dl, or a transfusion of whole blood or packed red blood cells, or any procedural intervention/surgery at the bleeding site to reverse/stop or correct the bleeding. Adverse events were reported if they occured at any time from cardiac catheterisation until 30 days after the procedure or hospital discharge, whichever occured earlier (episode of care), except for an embolic stroke, which was reported up to 72 hours after the procedure. If more than one catheterisation procedure was performed during the same episode of care, adverse events were captured until the subsequent cardiac catheterisation, except for bleeding and transfusion events, which are captured only up to 72 hours after the procedure. Death was not included as part of the adverse events, but reported separately as either death in the catheterisation laboratory or death within the same episode of care as defined above.
Table 3 Adverse events captured within the IMPACT registry.
AE=adverse events; ECMO=extracorporeal membrane oxygenation; IMPACT=IMproving Paediatric and Adult Congenital Treatment; LVAD=left ventricular assist device
* Events requiring ECMO or LVAD will be classified as a “Major adverse event” in the next version of the IMPACT registry (version 2)
Inclusion and exclusion criteria
Inclusion criteria:
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– Any case submitted to the IMproving Paediatric and Adult Congenital Treatment registry
Exclusion criteria:
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– Any case that only included one of the “core” interventional procedures, as defined in the specific methodlogy section
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– Any procedure that was solely diagnostic
Statistics
Basic descriptive data were calculated for all cardiac catheterisation cases and case types meeting the inclusion and exclusion criteria. Continuous variables are presented as median and interquartile range. Categorical variables are presented as frequency, using the number of cases for which the data element was provided as 100%.
Results
Basic demographic and clinical data
Within the IMproving Paediatric and Adult Congenital Treatment registry, a total of 8021 cases were classified as other procedures and/or multiple procedures, performed during 7691 episodes of care. These “non-core” cases formed the study cohort. The median weight was 23.1 kg (interquartile range 10, 9, 53.8). The age was <30 days for 451 (5.6%), equal to 30 days and below or equal to 1 year for 1017 (12.7%), above 1 year and below or equal to 18 years for 5210 (65.0%), and above 18 years for 1343 (16.7%) of the cases. A history of previous cardiac catheterisation was present in 6507 (82.4%) cases, and 619 (9.5%) cases underwent cardiac catheterisation within the preceding 30 days. A history of previous cardiac surgery was present in 6220 (78%) cases, and 996 (16%) cases had cardiac surgery within the preceding 30 days. Single ventricle anatomy was present in 1655 (20.7%) cases.
The majority of cases were performed electively (6738, 84.3%), followed by urgent (962, 12.0%), emergent (259, 3.2%), and salvage (32, 0.4%) procedures. General anaesthesia was used in 6202 (77.5%) cases, with elective intubation at the start in 4935 (61.5%) cases. The median case time was 80 minutes (interquartile range 39, 138), and the median amount of contrast administered was 2.1 ml/kg (interquartile range 0.3, 4.5). A systemic ventricular end-diastolic pressure equal to or above 18 mmHg was present in 352 (8.2%), and a cardiac index equal to or below 2.8 was present in 1663 (25.8%) of the cases.
Individual procedural data
A summary of all cases performed is listed in Tables 1 and 2. The most commonly performed case – in isolation or in combination with other procedures – was right ventricular biopsy, accounting for 3433 (42.8%) of all “non-core” cases within the IMproving Paediatric and Adult Congenital Treatment registry. Pulmonary artery interventions – in isolation or in combination with other procedures – were performed proximally in 738 (9.2%), peripherally in 451 (5.6%), and at the conduit/main pulmonary artery in 979 (12.2%) cases. Transcatheter pulmonary valve implantation was carried out in 374 (4.7%) cases. Aortopulmonary collaterals were occluded in 601 (7.5%), and venous collaterals were occluded in 253 (3.2%) of the cases.
Isolated case types are listed in Table 4. The longest median case times were seen for combined balloon angioplasty and stent placement in the peripheral pulmonary arteries (178 minutes) as well as the pulmonary veins (180 minutes), whereas the shortest median case times were seen for right ventricular biopsy (38 minutes) and patent foramen ovale occlusion (60 minutes). The only other isolated case type with a case time of <100 minutes was balloon angioplasty and/or stent placement within a Sano conduit, Blalock–Taussig shunt, or patent arterial duct (94 minutes).
Table 4 Basic characteristics of individual case types within the IMPACT registry.
AE=adverse events; BAS=balloon atrial septostomy; IMPACT=IMproving Paediatric and Adult Congenital Treatment; MPA=main pulmonary artery; PA=pulmonary artery; PDA=patent ductus arteriosus; RV=right ventricle; VSD=ventricular septal defect
* The listed atrial septal interventions (of any type) include all the patients with all underlying diagnoses, whether transposition of the great arteries, hypoplastic left heart syndrome, or any other diagnosis
Among all, four case types had an associated median use of contrast exceeding 5 ml/kg. These included multi-level pulmonary artery rehabilitation with balloon angioplasty and/or stent placement (5.0 ml/kg), balloon angioplasty and stent placement in the peripheral pulmonary arteries (5.7 ml/kg) or at the right ventricle-to-pulmonary artery conduit/main pulmonary artery (5.8 ml/kg), as well as vascular/valvar perforation cases (5.9 ml/kg).
Adverse events
Data on adverse events for individual case types are listed in Table 4. For the entire cohort, adverse events of any severity occurred in 957 (12.0%) cases, whereas major adverse events occurred in 113 (1.4%) cases (Fig 1); six patients (0.1%) died in the catheterisation laboratory, and 187 patients died within the same episode of care of causes not necessarily related to cardiac catheterisation. Cardiac arrest occurred in 76 (1.0%), cardiac tamponade in 15 (0.2%), embolic stroke in 5 (0.1%), device malposition requiring surgery in 10 (0.1%), device embolisation requiring retrieval in 30 (0.4%), new requirement for dialysis in 11 (0.1%), need for extra-corporal membrane oxygenation in 28 (0.4%), and an airway event requiring intubation in 59 (0.7%) cases. Bleeding events occurred in 140 (1.8%) cases, with 69 (49.6%) cases bleeding at the access site and 44 (31.7%) with a haematoma at the access site. Blood transfusion was administered in 387 (4.8%) cases. Arrhythmias occurred in 186 (2.3%), requiring cardioversion in 55 (29.6%), antiarrhythmic medication in 87 (46.8%), and temporary pacing in 16 (8.6%) of the cases, no permanent pacemaker was required. Secondary to a catheterisation complication, unplanned cardiac surgery was required in 25 (0.3%) and unplanned vascular surgery in 11 (0.1%) cases. Unplanned other surgery was required in 30 (0.4%) cases, 10.0% of which were secondary to catheter-related complications. Red blood cell transfusion was required in 387 (4.8%) cases.
For individual cases, the number of major adverse events was generally very low, and therefore difficult to compare, with only five case categories having more than three cases with a major adverse event. These were balloon angioplasty and/or stent placement in the Sano conduit, shunt, or patent arterial duct (n=5, 2.8%), balloon atrial septostomy (n=13, 5.5%), as well as other atrial septal interventions with or without balloon atrial septostomy (n=10, 7.8%).
There were four case types where the incidence of cases with any adverse event was >30%, which included balloon angioplasty and stent placement in the peripheral pulmonary arteries (9/20, 45.0%), balloon angioplasty and stent placement in the pulmonary veins (7/21, 33.3%), balloon angioplasty and/or stent placement in the Sano conduit, shunt, or patent arterial duct (66/179, 37.5%), as well as vascular/valvar perforation (5/12, 41.7%).
In total, five case categories had <10% of cases with any type of adverse events. These included balloon angioplasty of the caval vein (6/72, 8.3%), patent foramen ovale occlusion (3/171, 1.8%), occlusion of a fenestration or baffle leak (6/95, 6.3%), right ventricular biopsy (108/3372, 3.2%), as well as mitral or tricuspid valvuloplasty (1/18, 5.6%).
Discussion
This report provides an overview of the types of “non-core” cases submitted to the IMproving Paediatric and Adult Congenital Treatment registry, excluding the “core” IMproving Paediatric and Adult Congenital Treatment procedure types that are reported separately.Reference Moore, Vincent and Beekman 10 Although a variety of registries have published data on individual case types as well as adverse events, beyond the results of the Congenital Cardiac Catheterization Project on Outcomes registry there are limited multi-centre data available on the frequency of the various case types that are performed in the cardiac catheterisation laboratory in the present era.
In this data set, the most commonly performed cases included many well-established case types such as pulmonary artery rehabilitation, right ventricular biopsy, collateral occlusion, as well as atrial septal interventions; however, it also included newer case types such as transcatheter pulmonary valve implantation, which was performed in almost 5% of “non-core” cases submitted to the IMproving Paediatric and Adult Congenital Treatment registry.
The incidence of any adverse events within the IMproving Paediatric and Adult Congenital Treatment registry among “non-core” cases was 12%, whereas major adverse events occurred in 1.4% of the cases. This lies within the range of adverse events reported for “core” interventional procedures, which ranged from 5.3 to 24.3% for any adverse events and from 0 to 3.3% for major adverse events, as reported by Moore et al.Reference Moore, Vincent and Beekman 10 It is important to note that the three of four case categories with the highest incidence of adverse events were among those least frequently performed (n<25 cases), whereas four of the five case categories with the lowest incidence of adverse events were among those more frequently performed case categories (n>70 cases).
For diagnostic cases captured in the IMproving Paediatric and Adult Congenital Treatment registry, any adverse events occurred in 10% of the cases, whereas major adverse events occurred in 1.4% of the cases, as reported by Vincent et al.Reference Vincent, Moore and Beekman 13 Given the very wide variability of case types captured within the group of “non-core” procedures, it is impossible to derive any more detailed conclusions from this data, however.
In addition to IMproving Paediatric and Adult Congenital Treatment data, the only other recent multi-centre registry data available on catheterisation-related adverse events originate from the Congenital Cardiac Catheterization Project on Outcomes registry.Reference Bergersen, Marshall and Gauvreau 1 It reported an incidence of any adverse event of 20% for interventional cases, with 9% being high-severity adverse events; however, the definition of adverse events was broad and not limited to just a few selected types of adverse events, as is the case with the IMproving Paediatric and Adult Congenital Treatment registry. Importantly, however, the incidence of life-threatening adverse events reported from the Congenital Cardiac Catheterization Project on Outcomes registry (2.1%) was more similar to the incidence of major adverse events of 1.4% reported in the present study.Reference Lin, Hegde and Marshall 14
Although the incidence of adverse events is difficult to compare between these two registries, all four case types of the IMproving Paediatric and Adult Congenital Treatment registry that had associated adverse events in >30% of cases had previously also been identified as high-risk “procedure type risk groups” by the data derived from the Congenital Cardiac Catheterization Project on Outcomes registry.Reference Bergersen, Gauvreau and Marshall 15 Further work has been completed on the IMproving Paediatric and Adult Congenital Treatment data set to develop a risk stratification and risk-adjustment method, and to compare this with the catheterisation for congenital heart disease adjustment for risk method derived from the Congenital Cardiac Catheterization Project on Outcomes data set, and these results will be forthcoming in the near future.Reference Bergersen, Gauvreau and Foerster 9 In addition, the procedural diversity shown in this report as well as the low rates of adverse events necessitate the development of a risk-adjustment methodology in IMproving Paediatric and Adult Congenital Treatment to allow for equitable comparisons among institutions in the future, work that is presently being completed within a focussed working group of the IMproving Paediatric and Adult Congenital Treatment registry.
Furthermore, one of the few case types that allowed comparison with recent data available from other registries was endomyocardial biopsy, which accounted for >40% of all “non-core” cases submitted to the IMproving Paediatric and Adult Congenital Treatment registry. Among the biopsy cases submitted to the IMproving Paediatric and Adult Congenital Treatment registry, the rate of any adverse event was 3.2% and major adverse events 0.6%. This is very similar to recent results reported from the Congenital Cardiac Catheterization Project on Outcomes registry collected from eight centres, which documented an overall adverse event rate of 3.3% with 1.1% of high-severity adverse events.Reference Daly, Marshall and Vincent 16 Median case times were 38 minutes for the biopsy data derived from the IMproving Paediatric and Adult Congenital Treatment registry and 30 minutes for the Congenital Cardiac Catheterization Project on Outcomes data.
Pulmonary artery rehabilitation, both proximal and peripheral, accounted for >10% of all “non-core” cases. Individual data were difficult to compare with other series, as most reports were single-centre experiences, with only the Congenital Cardiac Catheterization Project on Outcomes registry reporting a recent multi-centre experience.Reference Holzer, Gauvreau and Kreutzer 7 Furthermore, the location of the intervention, proximal versus peripheral, as well as the number of interventions performed make it difficult to compare these data with other reports. Within the IMproving Paediatric and Adult Congenital Treatment data set, the incidence of any adverse event associated with pulmonary artery balloon angioplasty was 13.0% for proximal locations and 13.8% for peripheral locations, with major adverse events occurring in <1% of the cases. In contrast, the Congenital Cardiac Catheterization Project on Outcomes registry reported rates of high severity adverse events (level 3–5) for different types of balloon angioplasty between 9 and 14%;Reference Holzer, Gauvreau and Kreutzer 7 however, it is important to point out that level 3–5 adverse events as reported in the Congenital Cardiac Catheterization Project on Outcomes registry do include many adverse events that would not be classified as a major adverse event in the IMproving Paediatric and Adult Congenital Treatment registry, and therefore comparison with life-threatening adverse events – only level 4 and level 5 – of the Congenital Cardiac Catheterization Project on Outcomes registry would be more appropriate.Reference Lin, Hegde and Marshall 14
Limitations
Despite being a large study cohort including a total of 8021 cases, the number of cases within individual case types was frequently still small, thereby somewhat limiting the ability to draw any more stringent conclusions from the data presented for many of the case categories. Furthermore, outcome metrics, other than adverse events, have not been firmly established for any of the presented case types, and as such these data do not allow for any conclusions relating to procedural efficacy; however, providing these data is crucial to aid establishing those metrics in the future. In addition, although attempts were made to present well-defined case types, the IMproving Paediatric and Adult Congenital Treatment registry does not collect some other important details such as whether multiple interventions of the same case category were performed in the same case in a given patient – for example, balloon angioplasty in a peripheral pulmonary artery branch in a single lesion would be categorised as the same case category in a case where five peripheral branches were treated through balloon angioplasty, which naturally would have an important impact on parameters such as, for example, case time. Other limitations of this study are inherent to the IMproving Paediatric and Adult Congenital Treatment registry itself, which includes, for example, the lack of longitudinal data collection. Comparison of adverse event data with other registries is often limited by very different definitions and inclusions of adverse events into the specific registries.
Conclusions
The IMproving Paediatric and Adult Congenital Treatment registry has provided important data on the frequency and spectrum of cardiac catheterisation procedures performed in the present era. For many procedures, more data and work are needed to identify more subtle differences between case categories, especially as it relates to the incidence of major adverse events, and to further develop a risk-adjustment methodology to allow equitable comparisons among institutions.
Acknowledgements
None.
Financial Support
This research received no specific grant from any funding agency, commercial, or not-for-profit sectors.
Conflicts of Interest
None.
