Risk Factors for Adverse Events After Catheter-based Procedures in Adolescents and Adults with Congenital Heart Disease: A Report from the IMPACT Registry

Educational Objectives

After completing the activity, the clinician will be better able to estimate risk of adverse events after catheter-based procedures in adolescents and adults with congenital heart disease.

Summary

Interviewer: W. Douglas Weaver, MD, MACC

Take-home Messages:

• While general risk prediction has been available for pediatric and adult patients with congenital heart disease, there has been little guidance for estimating risk relating to catheterization for these patients.
• Investigators used a large registry that was designed to measure variability in performance and outcomes of cardiac catheterization procedures in all children and adults with congenital heart disease.
• They developed and validated a risk score to better predict adverse events related to catheter-based procedures, which appears to be robust for risk estimation in a broad range of patient subgroups.

Just getting a body of data can be a challenge in patients with adult congenital heart disease (ACHD), let alone developing evidence-based guidelines for ACHD. The latter, as pointed out by Ada C. Stefanescu Schmidt, MD, in a recent editorial,¹ is particularly difficult for several reasons.

Randomized controlled trials (RCT) provide the foundation of data for most cardiac guidelines; however, heterogeneity of diagnoses and physiologic variations lead to relatively small populations in ACHD, so studies require long recruitment periods. Today, individuals also emerge from childhood surgery with a different footprint than those in prior decades, further complicating the interpretation and relevance of past RCTs.

One way to gather more data is to use large collections of data. Recently, Dr. Stefanescu Schmidt and colleagues extracted serial cross-sectional data from the United States Nationwide Inpatient Sample to evaluate hospitalizations that included the diagnostic code for tetralogy of Fallot (TOF) from 2000 to 2011.² They analyzed 20,545 admissions for patients with TOF.

Over the decade, hospitalized patients with TOF became significantly more medically complex, with significant increases in comorbidities, cardiovascular procedures, and cost of hospitalization. The authors emphasized that the increase in the prevalence of obesity, hypertension, and diabetes in this young population underscores the need for preventive efforts focused on modifiable risk factors, in addition to treatment of heart failure and arrhythmia.

Catheterization in ACHD

The risk factors are well known for major adverse events (MAE) related to catheterization in a population without congenital heart disease. In general, risk factors include older age; female sex; the presence of vascular disease, heart failure, or diabetes; and renal dysfunction. Specific to transcatheter aortic valve replacement, the general risk factors include (once again) age and renal dysfunction, male sex, severe emphysema, nontransfemoral access, and a high Society of Thoracic Surgeons Predicted Risk of Mortality score.

The reason to better understand risk is simple: risk prediction is actionable. Understanding specific risks enables better outcomes when it permits adjusting interventions or therapies to accommodate a specific patient profile.

To better understand the risk factors for adverse events related to catheter-based procedures, Dr. Stefanescu Schmidt led an analysis of the IMPACT Registry (Improving Pediatric and Adult Congenital Treatments). This registry allows investigators to measure variability in the performance and outcomes of both diagnostic and interventional cardiac catheterization procedures in all children and adults with congenital heart disease. In this study, they evaluated data from 27,293 index procedures conducted in 87 hospitals. Of these, 19,105 were used as the derivation cohort while the rest (n = 8,188) made up the validation cohort.

The team developed a risk score that can facilitate assessment of individual patients (Table 1). As scores increased from 0 to 12+, so too did the risk for MAE, with the greatest increase seen between 7 to 11 points and 12+; indeed, there was a 3-fold increased risk of MAE between these 2 risk score ranges.

The model was robust across various subgroups of patients, including adolescents and adults, severity class, procedural risk category, and whether the patient had been in the intensive care unit before or after the procedure.

Table 1. Risk Score to Predict Adverse Events After Catheter-based Procedures in Adolescents and Adults with Congenital Heart Disease

Variable	Points
Preprocedural oxygen saturation <96%	1
Age 19 to 40 years	1
Age 41 to 65 years	2
Age >65 years	3
Underweight body mass index (adjusted for age)	2
No history of prior cardiac catheterization or surgeries	2
Preprocedural anticoagulation	2
History of renal insufficiency	3
Hemoglobin <11 g/dl	4
Moderate-risk procedure	4
High-risk procedure	5
Urgent procedure	7
Emergent/salvage procedure	14

 

Table 2. Procedural Risk Categories and Examples in Patients with Congenital Heart Disease

Low Risk	Intermediate Risk	High Risk
Atrial septostomy, balloon	Any catheterization within 72 hours of surgery	Atrial septostomy dilation and stent
Balloon angioplasty (native RV outflow tract, proximal PA, dilation <8 atmospheres, RV to PA conduit)	Balloon angioplasty (aorta or other systemic artery, lobar segment PA [dilation ≤8 atm and <4 vessels], systemic shunt or vein)	Balloon angioplasty (lobar segment PA [dilation ≥8 atm and <4 or >4 vessels], pulmonary vein (or stenting)
Diagnostic biopsy in patient ≥10 kg	Biopsy in patient <10 kg (not transplant)	Interventional techniques (atretic valve perforation)
Device closure (ASD, PFO, patent ductus arteriosus)	Device closure (baffle leak, systemic artery)	Device closure (paravalvular leak, ventricular septal defect)
Coronary angioplasty and stenting; stent relation (aorta or other systemic artery, intracardiac atria, proximal PA, RV to PA conduit, systemic vein)	Stent placement (aorta, intracardiac atria), lobar segment PA, native RV outflow tract, proximal PA, RV to PA conduit, RV outflow tract after surgery (no conduit)	Stent placement (intracardiac ventricular, systemic shunt or ductus arteriosus, pulmonary vein, peripheral PA)

ASD = atrial septal defect; PA = pulmonary artery; PFO = patent foramen ovale; RV = right ventricular

The validation cohort suggests this is now the first data-driven score to counsel congenital heart disease adolescents and adults prior to catheterization. The risk factors relate primarily to patient medical complexity (older age, history of renal disease, preprocedural anticoagulant use, lower hemoglobin, and being underweight). Also important: increased severity of congenital disease (lower oxygen saturation) and procedural variables, such as nonelective procedures and higher procedural risk (Table 2).

Interestingly, no history of prior catheterizations or cardiac surgery was an independent predictor of higher risk compared to patients with 1 to 3 or more than 3 procedures. This unexpected finding may be attributable to a couple of factors. These individuals tended to be older and more likely to require more urgent or higher-risk procedures. It is possible that these patients had been lost to care or lost to follow-up for some time or were at an older age at the time of diagnosis.

For now, the investigators think their model can be used to individualize risk/benefit discussions. However, the next step must be validation of the risk score in other national or multinational datasets.

Readings

1. Stefanescu Schmidt AC, Bhatt AB. Increasing the evidence base in adult congenital heart disease. Heart 2016;102:1701-2.

2. Stefanescu Schmidt AC, DeFaria Yeh D, Tabtabai S, Kennedy KF, Yeh RW, Bhatt AB. National Trends in Hospitalizations of Adults with Tetralogy of Fallot. Am J Cardiol 2016;118:906-11.

Disclosures

Ada Stefanescu Schmidt, MD
This author has nothing to disclose.

Interviewer: W. Douglas Weaver, MD, MACC
Mesoblast Ltd (D); Biotronix GmbH (D); CSL Behring Inc (D); Janssen Global Services LLC (D); Boston Scientific Corp (D); SYMETIS (D); GlaxoSmithKline plc (G)

The planning committee reported nothing to disclose.

A = Advisory panel B = Speakers’ bureau C = Consultant fees/honoraria D = Data and Safety Monitoring Board E = Equity interests/stock options F = Fellowship support G = Grant support L = Licensing Agreement O = Other relationship R = Royalties S = Salary W = Expert witness

Acknowledgements

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 0 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 0 CE contact hours.

Lecture ID:

AC490417

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.

More Details - Certification & Accreditation