Imaging of congenital heart disease in adults: choice of modalities

Recommendations for cardiovascular magnetic resonance and computed tomography in congenital heart disease: a consensus paper from the CMR/CCT Working Group of the Italian Society of Pediatric Cardiology and the Italian College of Cardiac Radiology endorsed by the Italian Society of Medical and Interventional Radiology (Part II)

Cardiovascular magnetic resonance (CMR) and computed tomography (CCT) are advanced imaging modalities that recently revolutionized the conventional diagnostic approach to congenital heart diseases (CHD), supporting echocardiography and often replacing cardiac catheterization. This is the second of two complementary documents, endorsed by experts from the Working Group of the Italian Society of Pediatric Cardiology and the Italian College of Cardiac Radiology of the Italian Society of Medical and Interventional Radiology, aimed at giving updated indications on the appropriate use of CMR and CCT in different clinical CHD settings, in both pediatrics and adults. In this article, support is also given to radiologists, pediatricians, cardiologists, and cardiac surgeons for indications and appropriateness criteria for CMR and CCT in the most referred CHD, following the proposed new criteria presented and discussed in the first document. This second document also examines the impact of devices and prostheses for CMR and CCT in CHD and additionally presents some indications for CMR and CCT exams when sedation or narcosis is needed.

Ambulatory sedation for children under 6 years with CHD in MRI and CT

INTRODUCTION

In infants and young children, good image quality in MRI and CT requires sedation or general anesthesia to prevent motion artefacts. This study aims to determine the safety of ambulatory sedation for children with CHD in an outpatient setting as a feasible alternative to in-hospital management.

METHODS

We recorded 91 consecutive MRI and CT examinations of patients with CHD younger than 6 years with ambulatory sedation. CHD diagnoses, vital signs, applied sedatives, and adverse events during or after ambulatory sedation were investigated.

RESULTS

We analysed 91 patients under 72 months (6 years) of age (median 26.0, range 1-70 months; 36% female). Sixty-eight per cent were classified as ASA IV, 25% as ASA III, and 7% as ASA II (American Society of Anesthesiologists Physical Status Classification). Ambulatory sedation was performed by using midazolam, propofol, and/or S-ketamine. The median sedation time for MRI was 90 minutes (range 35-235 minutes) and 65 minutes for CT (range 40-280 minutes). Two male patients (age 1.5 months, ASA II, and age 17 months, ASA IV) were admitted for in-hospital observation due to unexpected severe airway obstruction. The patients were discharged without sequelae after 1 and 3 days, respectively. All other patients were sent home on the day of examination.

CONCLUSION

In infants and young children with CHD, MRI or CT imaging can be performed under sedation in an outpatient setting by a well-experienced team. In-hospital backup should be available for unexpected events.

Recommendations for cardiovascular magnetic resonance and computed tomography in congenital heart disease: a consensus paper from the CMR/CCT working group of the Italian Society of Pediatric Cardiology (SICP) and the Italian College of Cardiac Radiology endorsed by the Italian Society of Medical and Interventional Radiology (SIRM) Part I

Cardiovascular magnetic resonance (CMR) and computed tomography (CCT) are advanced imaging modalities that recently revolutionized the conventional diagnostic approach to congenital heart diseases (CHD), supporting echocardiography and often replacing cardiac catheterization. Nevertheless, correct execution and interpretation require in-depth knowledge of all technical and clinical aspects of CHD, a careful assessment of risks and benefits before each exam, proper imaging protocols to maximize diagnostic information, minimizing harm. This position paper, written by experts from the Working Group of the Italian Society of Pediatric Cardiology and from the Italian College of Cardiac Radiology of the Italian Society of Medical and Interventional Radiology, is intended as a practical guide for applying CCT and CMR in children and adults with CHD, wishing to support Radiologists, Pediatricians, Cardiologists and Cardiac Surgeons in the multimodality diagnostic approach to these patients. The first part provides a review of the most relevant literature in the field, describes each modality's advantage and drawback, making considerations on the main applications, image quality, and safety issues. The second part focuses on clinical indications and appropriateness criteria for CMR and CCT, considering the level of CHD complexity, the clinical and logistic setting and the operator expertise.

Left, but not right, ventricular status determines heart failure in adults with Ebstein anomaly - A case-control study based on magnetic resonance

BACKGROUND

Ebstein anomaly (EA) is a congenital heart defect affecting the right heart. Heart failure (HF) is a significant complication in adults with EA. It may result not only from the right ventricle (RV), but also from the left ventricle (LV) abnormalities. We evaluate the size and function of both ventricles in patients with EA in cardiac magnetic resonance (CMR); to assess their association with the clinical markers of HF.

METHODS

Study group: 37 unoperated adults with EA (mean age 43.0 ± 14.4y, 21[56.8%] males).

CONTROLS

25 volunteers (mean age 39.9 ± 10.9y, 15[60%] males). Study protocol included: CMR [ejection fraction (EF), end-diastolic (EDVind) and stroke volumes (SVind) indexed by body surface area]; cardiopulmonary test (peak VO2, %peak VO2, VE/VCO2 slope).

RESULTS

Size and systolic function of LV were reduced comparing to the controls [LVEDVind (ml/m2): 63.7(range 38.7-94.2) vs. 79.3(48.7-105.1), p < 0.001; LV SVind (ml/m2): 35.8(22.9-55.1) vs. 49.2(37.8-71.7), p < 0.0001; LVEF(%): 58.3(34-70.5) vs. 62.0(52.0-77.0), p = 0.009]. RV was enlarged comparing to the controls [RVEDVind (ml/m2): 124.3(52.8-378.9) vs. 83.0(64.0-102.0), p < 0.0001) with impaired systolic function (RV SVind (ml/m2): 22.7(11.1-74.1) vs. 48.0(37.8-71.7), p < 0.0001; RVEF(%): 38.0(21.0-66.1) vs. 59.0(49.0-69.0), p < 0.0001). A significant correlation was found between LVEDVind vs. peakVO2 (r = 0.52, p = 0.001); LV SVind vs. peakVO2 (r = 0.47,p = 0.005). There was no correlation between the right ventricular status and exercise capacity.

CONCLUSIONS

In adults with Ebstein anomaly the size of left ventricle is reduced, right ventricle is enlarged; the function of both is impaired. Abnormal exercise capacity is associated with left ventricular status. Ventricular interdependence probably plays a role in heart failure pathomechanism.

Narrative review of Ebstein's anomaly beyond childhood: Imaging, surgery, and future perspectives

Ebstein's anomaly is a rare congenital heart disease with malformation of the tricuspid valve and myopathy of the right ventricle. The septal and inferior leaflets adhere to the endocardium due to failure of delamination. This leads to apical displacement of their hinge points with a shift of the functional tricuspid valve annulus towards the right ventricular outflow tract with a possibly restrictive orifice. Frequently, a coaptation gap yields tricuspid valve regurgitation and over time the "atrialized" portion of the right ventricle may dilate. The highly variable anatomy determines the clinical presentation ranging from asymptomatic to very severe with need for early operation. Echocardiography and magnetic resonance imaging are the most important diagnostic modalities to assess the tricuspid valve as well as ventricular morphology and function. While medical management of asymptomatic patients can be effective for many years, surgical intervention is indicated before development of significant right ventricular dilatation or dysfunction. Onset of symptoms and arrhythmias are further indications for surgery. Modified cone reconstruction of the tricuspid valve is the state-of-the-art approach yielding the best results for most patients. Alternative procedures for select cases include tricuspid valve replacement and bidirectional cavopulmonary shunt depending on patient age and other individual characteristics. Long-term survival after surgery is favorable but rehospitalization and reoperation remain significant issues. Further studies are warranted to identify the optimal surgical strategy and timing before adverse right ventricular remodeling occurs. It is this article's objective to provide a comprehensive review of current literature and an overview on the management of Ebstein's Anomaly. It focuses on imaging, cardiac surgery, and outcome. Additionally, a brief insight into arrhythmias and their management is given. The "future perspectives" summarize open questions and fields of future research.

Effects of Choice of Medical Imaging Modalities on a Non-invasive Diagnostic and Monitoring Computational Framework for Patients With Complex Valvular, Vascular, and Ventricular Diseases Who Undergo Transcatheter Aortic Valve Replacement

Due to the high individual differences in the anatomy and pathophysiology of patients, planning individualized treatment requires patient-specific diagnosis. Indeed, hemodynamic quantification can be immensely valuable for accurate diagnosis, however, we still lack precise diagnostic methods for numerous cardiovascular diseases including complex (and mixed) valvular, vascular, and ventricular interactions (C3VI) which is a complicated situation made even more challenging in the face of other cardiovascular pathologies. Transcatheter aortic valve replacement (TAVR) is a new less invasive intervention and is a growing alternative for patients with aortic stenosis. In a recent paper, we developed a non-invasive and Doppler-based diagnostic and monitoring computational mechanics framework for C3VI, called C3VI-DE that uses input parameters measured reliably using Doppler echocardiography. In the present work, we have developed another computational-mechanics framework for C3VI (called C3VI-CT). C3VI-CT uses the same lumped-parameter model core as C3VI-DE but its input parameters are measured using computed tomography and a sphygmomanometer. Both frameworks can quantify: (1) global hemodynamics (metrics of cardiac function); (2) local hemodynamics (metrics of circulatory function). We compared accuracy of the results obtained using C3VI-DE and C3VI-CT against catheterization data (gold standard) using a C3VI dataset (N = 49) for patients with C3VI who undergo TAVR in both pre and post-TAVR with a high variability. Because of the dataset variability and the broad range of diseases that it covers, it enables determining which framework can yield the most accurate results. In contrast with C3VI-CT, C3VI-DE tracks both the cardiac and vascular status and is in great agreement with cardiac catheter data.

Exercise cardiac magnetic resonance imaging to assess dynamic right ventricular outflow tract obstruction in congenital heart disease: a case report

Background

Right ventricular outflow tract obstruction in patients with congenital heart disease is usually assessed using echocardiographic peak instantaneous gradient at rest. Since right ventricular outflow tract obstruction may change during exercise (dynamic right ventricular outflow tract obstruction), we present a case emphasizing the potential use of exercise cardiac magnetic resonance imaging (CMR).

Case summary

We discuss a 15-year-old patient with repaired mid-ventricular sub-pulmonary stenosis type double-chambered right ventricle causing right ventricular outflow tract obstruction and symptoms on exertion. In this case, exercise CMR imaging provided additional information, allowing adequate surgical planning.

Discussion

The additional value of exercise CMR imaging in a case of right ventricular outflow tract obstruction was described. Although exercise cardiac magnetic resonance imaging did not show a significant increase in peak gradient across the right ventricular outflow tract obstruction, shifting and D-shaping of the interventricular septum with subsequent insufficient left ventricular filling (preload) was observed in the patient with recurrent double-chambered right ventricle. This case demonstrates how exercise CMR imaging can be helpful in the clinical decision beyond standard echocardiographic evaluation by providing additional evidence of adverse haemodynamics during exercise.

Diagnosis and treatment of right ventricular dysfunction in congenital heart disease

Right ventricular (RV) function is important for clinical status and outcomes in children and adults with congenital heart disease (CHD). In the normal RV, longitudinal systolic function is the major contributor to global RV systolic function. A variety of factors contribute to RV failure including increased pressure- or volume-loading, electromechanical dyssynchrony, increased myocardial fibrosis, abnormal coronary perfusion, restricted filling capacity and adverse interactions between left ventricle (LV) and RV. We discuss the different imaging techniques both at rest and during exercise to define and detect RV failure. We identify the most important biomarkers for risk stratification in RV dysfunction, including abnormal NYHA class, decreased exercise capacity, low blood pressure, and increased levels of NTproBNP, troponin T, galectin-3 and growth differentiation factor 15. In adults with CHD (ACHD), fragmented QRS is independently associated with heart failure (HF) symptoms and impaired ventricular function. Furthermore, we discuss the different HF therapies in CHD but given the broad clinical spectrum of CHD, it is important to treat RV failure in a disease-specific manner and based on the specific alterations in hemodynamics. Here, we discuss how to detect and treat RV dysfunction in CHD in order to prevent or postpone RV failure.

Noninvasive imaging of congenital cardiovascular defects

Advances in the treatment have drastically increased the survival rate of congenital heart disease (CHD) patients. Therefore, the prevalence of these patients is growing. Imaging plays a crucial role in the diagnosis and management of this population as a key component of patient care at all stages, especially in those patients who survived into adulthood. Over the last decades, noninvasive imaging techniques, such as cardiac magnetic resonance (CMR) and cardiac computed tomography (CCT), progressively increased their clinical relevance, reaching stronger levels of accuracy and indications in the clinical surveillance of CHD. The current review highlights the main technical aspects and clinical applications of CMR and CCT in the setting of congenital cardiovascular abnormalities, aiming to address a state-of-the-art guidance to every physician and cardiac imager not routinely involved in the field.

Imaging Modalities in Congenital Heart Disease

Cardiac imaging provides invaluable guidance at all stages of the management of congenital heart disease. Advances in the field of cardiac imaging have contributed immensely to improved outcomes of these patients. Echocardiography remains the first-line imaging modality. Non-invasive cross-sectional imaging using computed tomography and magnetic resonance imaging supplements morphologic and physiologic evaluation and are being increasingly used for diagnosis and follow-up of patients with a malformed heart. Cardiac catheterization, being invasive, is mostly reserved for accurate assessment of hemodynamic status and percutaneous interventions. Simultaneous improvement in visualization techniques has amplified the information obtained from various imaging modalities. This review provides an overview of cardiac imaging and visualization techniques commonly used in the diagnosis and management of patients with congenital heart disease.

Aortic elasticity after aortic coarctation relief: comparison of surgical and interventional therapy by cardiovascular magnetic resonance imaging

Background

Patients after aortic coarctation (CoA) repair show impaired aortic bioelasticity and altered left ventricular (LV) mechanics, predisposing diastolic dysfunction. Our purpose was to assess aortic bioelasticity and LV properties in CoA patients who underwent endovascular stenting or surgery using cardiovascular magnetic resonance (CMR) imaging.

Methods

Fifty CoA patients (20.5 ± 9.5 years) were examined by 3-Tesla CMR. Eighteen patients had previous stent implantation and 32 had surgical repair. We performed volumetric analysis of both ventricles (LV, RV) and left atrium (LA) to measure biventricular volumes, ejection fractions, left atrial (LA) volumes, and functional parameters (LAEF_Passive, LAEF_Contractile, LAEF_Reservoir). Aortic distensibility and pulse wave velocity (PWV) were assessed. Native T1 mapping was applied to examine LV tissue properties. In twelve patients post-contrast T1 mapping was performed.

Results

LV, RV and LA parameters did not differ between the surgical and stent group. There was also no significant difference for aortic distensibility, PWV and T1 relaxation times. Aortic root distensibility correlated negatively with age, BMI, BSA and weight (p < 0.001). Native T1 values correlated negatively with age, weight, BSA and BMI (p < 0.001). Lower post-contrast T1 values were associated with lower aortic arch distensibility and higher aortic arch PWV (p < 0.001).

Conclusions

CoA patients after surgery or stent implantation did not show significant difference of aortic elasticity. Thus, presumably other factors like intrinsic aortic abnormalities might have a greater impact on aortic elasticity than the approach of repair. Interestingly, our data suggest that native T1 values are influenced by demographic characteristics.

EDUCATIONAL SERIES IN CONGENITAL HEART DISEASE: Cardiovascular MRI and CT in congenital heart disease

Cardiovascular MRI and CT are useful imaging modalities complimentary to echocardiography. This review article describes the common indications and consideration for the use of MRI and CT in the management of congenital heart disease.

Right ventricular systolic dysfunction at rest is not related to decreased exercise capacity in patients with a systemic right ventricle

BACKGROUND

To evaluate the relationship between right ventricular (RV) systolic dysfunction at rest and reduced exercise capacity in patients with a systemic RV (sRV).

METHODS

All patients with congenitally corrected transposition of the great arteries (ccTGA) or complete TGA after atrial switch (TGA-Mustard/Senning) followed in our institution between July 2011 and September 2017 who underwent cardiac imaging within a six-month time period of cardiopulmonary exercise testing (CPET) were analyzed. We assessed sRV systolic function with TAPSE and fractional area change on echocardiogram and, if possible, with ejection fraction, global longitudinal and circumferential strain on cardiac magnetic resonance (CMR) imaging.

RESULTS

We studied 105 patients with an sRV (median age 34 [IQR 28-42] years, 29% ccTGA and 71% TGA-Mustard/Senning) of which 39% had either a pacemaker (n = 17), Eisenmenger physiology (n = 6), severe systemic atrioventricular valve regurgitation (n = 14), or peak exercise arterial oxygen saturation < 92% (n = 17). Most patients were asymptomatic or mildly symptomatic (NYHA class I/II/III in 71/23/6%). Sixty-four percent had evidence of moderate or severe sRV dysfunction on cardiac imaging. Mean peak oxygen uptake (pVO2) was 24.1 ± 7.4 mL/kg/min, corresponding to a percentage of predicted pVO2 (%ppVO2) of 69 ± 17%. No parameter of sRV systolic function as evaluated on echocardiography (n = 105) or CMR (n = 46) was correlated with the %ppVO2, even after adjusting for associated cardiac defects or pacemakers.

CONCLUSIONS

In adults with an sRV, there is no relation between echocardiographic or CMR-derived sRV systolic function parameters at rest and peak oxygen uptake. Exercise imaging may be superior to evaluate whether sRV contractility limits exercise capacity.

Echocardiographic arterial measurements in complex congenital diseases before bidirectional Glenn: comparison with cardiovascular magnetic resonance imaging

Aims

This study sought to investigate diagnostic accuracy of echocardiographic measures of great vessels in patients before bidirectional cavopulmonary connection (BCPC) compared with cardiovascular magnetic resonance (CMR).

Methods and results

Seventy-two patients (61% after Norwood operation) undergoing BCPC between 2007 and 2012 were assessed pre-operatively using echocardiography and CMR. Bland-Altman analysis and correlation coefficients were used for comparison of echocardiography and CMR measurements. Sensitivity, specificity, and positive and negative predictive values were calculated to assess the ability of echocardiography to detect vessel stenosis. Twenty-four percent of all vessel measurements could not be made by echocardiography due to poor image quality. Acquisition of unsatisfactory images was higher in non-sedated patients. Although there was a reasonable correlation (0.68-0.90) and low bias (-0.8 to 0.5), there were wide limits of agreement between echocardiography and CMR demonstrating poor agreement. Sensitivity and specificity for pulmonary branches were moderate [sensitivity for right pulmonary artery (RPA) 67%, left pulmonary artery (LPA) 54%, specificity for RPA 65%, LPA 72%] with low levels of accuracy (RPA and LPA 42%). Sensitivity, specificity, and accuracy were better for aorta (82, 86, and 63%, respectively).

Conclusion

This study demonstrates modest agreement between echocardiographic and CMR measures of vessel diameter and stenosis detection. Approximately a quarter of all vessel segments could not be measured using echocardiography due to poor image quality, which was significantly lower in non-sedated patients. These findings show that echocardiography cannot substitute CMR for reliable identification of great vessel stenoses in complex patients prior to the BCPC, particularly those with Blalock-Taussig shunts.

The Role of Pulmonary Scintigraphy in the Evaluation of Adults with Congenital Heart Disease

Adults with congenital heart disease represent a growing population with challenging and complex medical management. Pulmonary scintigraphy can play a valuable role in the evaluation and care of this patient population. We present a review of the variety of clinical scenarios where pulmonary scintigraphy can be helpful in the evaluation of adults with congenital heart disease, along with technical considerations associated with these studies.

Assessment of myocardial function using MRI-based feature tracking in adults after atrial repair of transposition of the great arteries: Reference values and clinical utility

BACKGROUND

Echocardiographic parameters of ventricular deformation of the systemic right ventricle (sRV) predict adverse clinical outcome in patients after atrial repair of transposition of the great arteries (TGA). We assessed myocardial deformation on cardiac MRI (CMR) and correlated these with clinical and conventional CMR parameters in TGA patients.

METHODS

Retrospective analysis of CMR studies in 91 TGA patients (66% male; mean age 30.1±5.1years) at two tertiary adult congenital heart centers was conducted. Myocardial deformation was assessed by CMR-based feature tracking (FT), providing longitudinal (LS), radial (RS), and circumferential (CS) global strain for the sRV and the subpulmonary left ventricle. A subgroup of optimal TGA was defined (NYHA class I, NT-proBNP <300pg/ml, max. exercise work load ≥100watt, no significant clinical events) as a reference cohort.

RESULTS

There was a significant correlation between FT and conventional CMR parameters. Left ventricular ejection fraction (LVEF) correlated significantly with LV LS, RS, and CS (r between 0.24 and 0.34, p values between 0.03 and 0.005). sRVEF correlated with RV CS (r=0.56, p<0.001), and RV RS (r=0.32, p=0.007). QRS duration showed a negative correlation with RV CS (r=-0.53, p<0.001), LV RS (r=-0.34, p=0.008), and LV CS (r=-0.34, p=0.006). Reference values for the novel FT method in clinically optimal TGA patients are provided.

CONCLUSION

Assessment of myocardial function using CMR-based FT is feasible in TGA patients. FT measurements related to important prognostic clinical parameters. Furthermore, we provide for the first time reference values for TGA patients in an optimal clinical status.

Advanced flow MRI: emerging techniques and applications

Magnetic resonance imaging (MRI) techniques provide non-invasive and non-ionising methods for the highly accurate anatomical depiction of the heart and vessels throughout the cardiac cycle. In addition, the intrinsic sensitivity of MRI to motion offers the unique ability to acquire spatially registered blood flow simultaneously with the morphological data, within a single measurement. In clinical routine, flow MRI is typically accomplished using methods that resolve two spatial dimensions in individual planes and encode the time-resolved velocity in one principal direction, typically oriented perpendicular to the two-dimensional (2D) section. This review describes recently developed advanced MRI flow techniques, which allow for more comprehensive evaluation of blood flow characteristics, such as real-time flow imaging, 2D multiple-venc phase contrast MRI, four-dimensional (4D) flow MRI, quantification of complex haemodynamic properties, and highly accelerated flow imaging. Emerging techniques and novel applications are explored. In addition, applications of these new techniques for the improved evaluation of cardiovascular (aorta, pulmonary arteries, congenital heart disease, atrial fibrillation, coronary arteries) as well as cerebrovascular disease (intra-cranial arteries and veins) are presented.

Aortic Measurements in Patients with Aortopathy are Larger and More Reproducible by Cardiac Magnetic Resonance Compared with Echocardiography

Accurate and reproducible aortic measurements are essential in aortopathy patients. Transthoracic echocardiography (TTE) is commonly used but has several limitations. Cardiac magnetic resonance (CMR) can offset these limitations but has not been directly compared with TTE. We compared the reproducibility of CMR and TTE measurements at multiple aortic levels. Patients with a connective tissue disorder (CTD) or bicommissural aortic valve (BAV) (n = 41; 22 CTD, 19 BAV; mean age 18.8 ± 8.9 years) with TTE and CMR imaging performed within 3 months of each other were randomly selected. Two blinded observers measured the aorta at multiple anatomic levels. Intra- and interobserver variability and agreement between techniques were assessed. Aortic root diameter measurements by TTE and CMR were equally reproducible (% error 4-10 %), but TTE measurements were systematically smaller by 5-7 % (p < 0.0001). Systematic differences were larger in BAV (11-12 %, p < 0.0001) due to root asymmetry. CMR measurements of aortic root cross-sectional area were feasible and highly reproducible (% error 5-8 %). Compared with CMR, ascending aorta measurements by TTE were less reproducible, especially in BAV (% error 21-24 vs. 6-7 %, p = 0.01). Distal aortic measurements by TTE were 14-29 % smaller and had poor reproducibility compared with CMR (% error 24-42 vs. 9-10 %; p < 0.0001). CMR measurement of the largest aortic root dimension is more reliable than TTE, especially when the root is asymmetric. Measurements of the thoracic aorta distal to the root by CMR are more accurate and reproducible than by TTE. These data support a role for CMR in aortopathy patients.

The year 2014 in the European Heart Journal--Cardiovascular Imaging: part II

The European Heart Journal-Cardiovascular Imaging, created in 2012, has become a reference for publishing multimodality cardiovascular imaging scientific and review papers. The impressive 2014 impact factor of 4.105 confirms the important position of our journal. In this part, we summarize the most important studies from the journal's third year, with specific emphasis on cardiomyopathies, congenital heart diseases, valvular heart diseases, and heart failure.

Usefulness of magnetic resonance imaging to guide referral for pulmonary valve replacement in repaired tetralogy of Fallot

The aim of this study was to determine if adult patients with repaired tetralogy of Fallot are being referred for pulmonary valve replacement (PVR) earlier on the basis of cardiac magnetic resonance imaging (CMR) parameters despite the absence of CMR-based recommendations in the American College of Cardiology and American Heart Association joint guidelines. Variables defined by the guidelines were analyzed in conjunction with CMR-based parameters across 3 groups defined by the release of the guidelines: (1) patients referred before the guidelines, (2) patients referred 0 to 3 years after the guidelines, and (3) patients referred ≥3 years after the guidelines. Seventy-nine patients were identified. No significant trend was observed in guideline-defined variables. Significant trends in indexed right ventricular end-diastolic volume (p = 0.034), indexed right ventricular end-systolic volume (p = 0.001), and the right ventricular ejection fraction (p = 0.005) were observed across groups. By multivariate regression, patients who underwent PVR ≥3 years after the release of the guidelines had a 29 ml/m(2) smaller indexed right ventricular end-diastolic volume (p = 0.01) and a 33 ml/m(2) smaller indexed right ventricular end-systolic volume (p <0.001) compared with patients who underwent PVR before the release of the guidelines. PVR 0 to 3 years after the guidelines was not a significant predictor of either indexed right ventricular end-diastolic volume (p = 0.93) or indexed right ventricular end-systolic volume (p = 0.18). Patients referred for PVR ≥3 years after the guidelines had significantly smaller CMR-based right ventricular volumes without significant trends in guideline-defined variables. Given the increased use of CMR to guide PVR referral, revisiting the guidelines to address appropriate use of CMR derived thresholds is indicated.

Heart failure in adult congenital heart disease

OPINION STATEMENT

Adult congenital heart disease (ACHD) patients represent a special population in modern cardiology: though their numbers are growing, and they represent a high-resource utilization subgroup, a robust evidence-base of randomized trials is lacking. Much of the standard therapy is adapted from the treatment of ischemic and idiopathic left ventricle systolic failure, with a small, but growing body of evidence on medical therapy in select ACHD diagnoses. At our institution, for instance, there is a long tradition of using angiotensin antagonists in patients with a systemic right ventricle to prevent deleterious remodeling. The effects of beta-blockers on functional class in ACHD are yet unproven, but there is promising data on pulmonary vasodilators. Control of coronary risk factors and aerobic exercise should be considered for all. Prevention of arrhythmias is important, and multi-site pacing is an emerging therapy. New prognostic tools including natriuretic peptides and CPET are increasingly used to guide earlier initiation of these therapies.