Daniel Tobler

Cardiac outcomes in young adult survivors of the arterial switch operation for transposition of the great arteries.

OBJECTIVES We sought to determine cardiac outcomes in young adults with complete transposition of the great arteries (TGA) after the arterial switch operation (ASO). BACKGROUND Although cardiac outcomes in the pediatric population with TGA after ASO have been well described, outcomes in the adult population have not to our knowledge been studied. METHODS We determined late survival in all operative survivors with TGA after ASO performed before 1991 at our local pediatric referring hospital. In the subset of adults (n = 65) followed in our adult congenital cardiac clinic, we examined cardiac outcomes in adulthood. RESULTS Survival of the 132 infants discharged from hospital after ASO was 97% (70% confidence interval [CI]: 95.0% to 98.1%) at 20 years. In the 65 patients (mean age 21 +/- 3 years, 62% male) followed at our institution, 17% (11 of 65) had at least 1 clinically significant cardiac lesion, including ventricular dysfunction, valvular dysfunction, or arrhythmias. Residual lesions were more common in those who had had cardiac reinterventions in childhood (odds ratio: 10.7, 95% CI: 2.1 to 55). In adulthood, 5 patients (8%) had arrhythmia requiring treatment and 7 patients (11%) required reinterventions (5 reoperations and 2 pacemaker implantations). Intervention for aortic valve regurgitation and aortic root dilation were not observed. Exercise capacity was reduced in most adults (82%) after ASO. CONCLUSIONS Although most adults after ASO are well, and few have residual defects, there are subgroups, particularly those who needed further cardiac intervention in childhood, who are at higher risk for ventricular and valve dysfunction and arrhythmias.

Generalised muscle weakness in young adults with congenital heart disease

Background In patients with heart failure from acquired cardiomyopathy, respiratory and skeletal muscle weakness is common and is an independent predictor for adverse events. Despite a different underlying pathology, many young adults with congenital heart disease (CHD) develop a syndrome comparable to heart failure from acquired cardiomyopathy and may be at risk for a similar skeletal muscle weakness. Objectives To assess respiratory and skeletal muscle strength in adults with complex CHD. Methods Respiratory and skeletal muscle function was assessed in 51 adults; 41 with complex CHD (16 tetralogy of Fallot, 11 univentricular anatomy with Fontan operation and 14 with subaortic right ventricles) and 10 controls. Maximal inspiratory (MIPs) and expiratory (MEPs) pressures, handgrip strength, lung volumes and aerobic capacity (peak VO2) were measured. Results In patients with CHD (age 34±13 years), average% predicted MIPs, MEPs and handgrip strength were lower than in controls (77±27% vs 106±28%, 85±32% vs 116±41% and 72±15% vs 93±14%, respectively, p≤0.01). There was no significant difference in muscle weakness between CHD subgroups. In 39% of patients with CHD, the handgrip strength, and in 22%, respiratory muscle strength was <70% predicted. These patients had a significantly lower peak VO2 (50±12% vs 64±14% predicted, p=0.008). Conclusion Respiratory and skeletal muscle weakness is common in young adults with complex CHD and similar to that found in older adults with advanced heart failure from acquired heart disease.

Cardiac Magnetic Resonance Imaging and the Assessment of Ebstein Anomaly in Adults

No published studies have evaluated the role of cardiac magnetic resonance (CMR) imaging for the assessment of Ebstein anomaly. Our objective was to evaluate the right heart characteristics in adults with unrepaired Ebstein anomaly using contemporary CMR imaging techniques. Consecutive patients with unrepaired Ebstein anomaly and complete CMR studies from 2004 to 2009 were identified (n = 32). Volumetric measurements were obtained from the short-axis and axial views, including assessment of the functional right ventricular (RV) end-diastolic volume (EDV) and end-systolic volume. The volume of the atrialized portion of the right ventricle in end-diastole was calculated as the difference between the total RVEDV and the functional RVEDV. The reproducibility of the measurements in the axial and short-axis views was determined within and between observers. The median value derived from the short-axis and axial views was 136 ml/m(2) (range 59 to 347) and 136 ml/m(2) (range 63 to 342) for the functional RVEDV, 153 ml/m(2) (range 64 to 441) and 154 ml/m(2) (range 67 to 436) for the total RVEDV, 49% (range 32% to 46%) and 50% (range 40% to 64%) for the functional RV ejection fraction, respectively. The axial measurements demonstrated lower intraobserver and interobserver variability than the short-axis approach for all values, with the exception of the intraobserver functional RVEDV and interobserver total RVEDV for which the limits of agreement and variance were not significantly different between the 2 views. In conclusion, measurements of right heart size and systolic function in patients with Ebstein anomaly can be reliably achieved using CMR imaging. Axial imaging appeared to provide more reproducible data than that obtained from the short-axis views.

Increasing Mortality Burden among Adults with Complex Congenital Heart Disease

BACKGROUND Progress in management of congenital heart disease has shifted mortality largely to adulthood. However, adult survivors with complex congenital heart disease are not cured and remain at risk of premature death as young adults. Thus, our aim was to describe the evolution and mortality risk of adult patient cohorts with complex congenital heart disease. METHODS Among 12,644 adults with congenital heart disease followed at a single center from 1980 to 2009, 176 had Eisenmenger syndrome, 76 had unrepaired cyanotic defects, 221 had atrial switch operations for transposition of the great arteries, 158 had congenitally corrected transposition of the great arteries, 227 had Fontan palliation, and 789 had repaired tetralogy of Fallot. We depict the 30-year evolution of these 6 patient cohorts, analyze survival probabilities in adulthood, and predict future number of deaths through 2029. RESULTS Since 1980, there has been a steady increase in numbers of patients followed, except in cohorts with Eisenmenger syndrome and unrepaired cyanotic defects. Between 1980 and 2009, 308 patients in the study cohorts (19%) died. At the end of 2009, 85% of survivors were younger than 50 years. Survival estimates for all cohorts were markedly lower than for the general population, with important differences between cohorts. Over the upcoming two decades, we predict a substantial increase in numbers of deaths among young adults with subaortic right ventricles, Fontan palliation, and repaired tetralogy of Fallot. CONCLUSIONS Anticipatory action is needed to prepare clinical services for increasing numbers of young adults at risk of dying from complex congenital heart disease.

The left heart after pulmonary valve replacement in adults late after tetralogy of Fallot repair.

BACKGROUND Adverse ventricular-ventricular interactions have been recognized in those with repaired tetralogy of Fallot (TOF) and severe pulmonary regurgitation. OBJECTIVE We aimed to examine the impact of pulmonary valve replacement (PVR) on the left heart late after TOF repair. METHODS AND RESULTS Left ventricular (LV) volumes and ejection fractions (EF) were analyzed in adults with severe pulmonary regurgitation after TOF repair with cardiac magnetic resonance imaging (CMR) before and after PVR. Thirty-nine patients (median age 33[20-65] years) were reviewed. Post-PVR, LVEF improved significantly in the entire cohort (50 ± 9%→54 ± 7%, p<0.001) and in those with moderately impaired (defined as LVEF ≤ 45%) preoperative LVEF (38 ± 5%→47 ± 6%, p<0.0001), but was not statistically different in those with relatively preserved (defined as LVEF >45%) preoperative LVEF. By multivariate linear regression analysis to evaluate independent CMR predictors of improved LVEF post-PVR for the entire cohort, the only CMR variable to emerge was preoperative LVEF (p=0.012, regression coefficient -0.54, SE 0.13). Whereas PVR resulted in increased LV filling in patients with relatively preserved preoperative LVEF reflected by an increase in LV end-diastolic volumes (77 ± 10→82 ± 16 mL/m(2), p=0.05), LV end-systolic volumes decreased after PVR in patients with impaired preoperative LVEF (65 ± 12→54 ± 10 mL/m(2), p=0.001) but LV end-diastolic volumes were not significantly changed. CONCLUSION When LVEF is decreased after TOF repair, PVR appears to have a salutary effect on postoperative LVEF, thereby supporting the concept of recovery of adverse right-left heart interactions. Mechanisms of left heart improvement post-PVR differ depending on degree of preoperative LV systolic dysfunction.

Echocardiography for Assessment of Right Ventricular Volumes Revisited: A Cardiac Magnetic Resonance Comparison Study in Adults with Repaired Tetralogy of Fallot

BACKGROUND The aim of this study was to develop a mathematical model using two-dimensional echocardiographic parameters to estimate right ventricular end-diastolic volume (RVEDVi) in adults with repaired tetralogy of Fallot. METHODS Linear regression equations were used to examine the relationship between two-dimensional echocardiographic and cardiac magnetic resonance (CMR) imaging measures of RVEDVi. Imaging studies in 101 adults were used to create and validate the model. The ability of the model to detect changes in CMR RVEDVi was tested in 57 adults with serial studies. RESULTS The optimal model to quantitate CMR RVEDVi included two-dimensional echocardiographic right ventricular end-diastolic area measured in the apical four-chamber view, indexed to body surface area (AreaDi) (CMR RVEDVi = 11.5 + [7 x AreaDi]). The model reliably allowed the detection of stable and changing CMR RVEDVi (kappa = 0.84 and kappa = 0.82, respectively, P < .0001). CONCLUSION Quantitative assessment of right-ventricular volumes by echocardiography is feasible and may be used for serial follow-up in patients with contraindications for CMR.

Knowledge of and preference for advance care planning by adults with congenital heart disease.

Congenital heart disease (CHD) is a chronic illness. Few adults with CHD are cured and those with disease of moderate or great complexity remain at risk of premature death. Current adult CHD guidelines recommend that providers encourage their patients to complete advance directives. We evaluated the prevalence of completed advance directives by and the preference for information about life expectancy of outpatients at a large adult CHD program. Two hundred patients with CHD (52% men, 35 ± 15 years old, range 18 to 79, 81% with disease of moderate or great complexity) completed a survey that assessed knowledge of advance directives and nature of and preferences for advance care planning. Only 5% of patients reported that they had completed advance directives; 56% had never heard of them. However, most patients (87%) reported that they would prefer to have an advance directive available if they were dealing with their own dying and were unable to speak for themselves. Patients who had formally identified substitute decision makers (n = 34) were typically older (47 ± 16 vs 33 ± 13 years, p <0.001) and more likely to have partners (30% vs 6%, p <0.001). Most patients (70%) reported that they wanted general information about the average life expectancy for patients with their heart condition. In conclusion, in contrast to recommendations from published guidelines, advance care planning documents are infrequently completed by outpatients. Health care providers caring for patients with CHD should educate their patients about advance directives and assist them in preparing formal end-of-life-planning documents.

End-of-life in adults with congenital heart disease: A call for early communication

BACKGROUND We investigated preferences of adults with congenital heart disease (CHD) and their health care providers regarding end-of-life (EOL) communication. METHODS Adult CHD outpatients and health care providers completed surveys about preferences for and experiences with EOL communication. Responses were compared between patients and providers. RESULTS Two hundred patients (18-79 years) and 48 CHD health care providers (primarily cardiologists) completed surveys. Only 2 patients (1%) indicated that they had discussed EOL planning with their medical team. In contrast, 50% of providers reported that they typically discuss issues including life expectancy, advance planning, and resuscitation preferences with their outpatients. Seventy-eight percent (156/199) of patients wanted their medical team to raise EOL issues; this preference was independent of disease complexity and socio-demographic factors. In contrast, providers reported that their EOL discussions increase in accordance with disease complexity (p<0.001). Early initiation of EOL discussions, before diagnosis with life-threatening complications, was favored by 62% of patients but only 38% of providers (p<0.001). CONCLUSION Health professionals caring for adults with CHD should explore preferences of their patients for EOL discussions earlier in the disease course, and not only with patients facing life-threatening complications and/or with complex conditions. When EOL discussions do occur, health care providers should attempt to ensure that patients better understand these conversations. Increased attention to EOL issues is proposed in order to improve the care of patients with CHD across the lifespan.

Impact of worsening renal function related to medication in heart failure

Renal failure is a major challenge in treating heart failure (HF) patients. HF medication may deteriorate renal function, but the impact thereof on outcome is unknown. We investigated the effects of HF medication on worsening renal function (WRF) and the relationship to outcome.

Right heart characteristics and exercise parameters in adults with Ebstein anomaly: New perspectives from cardiac magnetic resonance imaging studies

BACKGROUND The utility of cardiac magnetic resonance imaging (CMR) for assessment of adults with Ebstein anomaly is not well-defined. We sought to evaluate CMR characteristics in this population and to relate these to exercise parameters. METHODS We analyzed CMR studies in adults with unrepaired Ebstein anomaly for measures of severity of Ebstein disease, including atrialized, functional and total right ventricular (RV) volumes, ejection fraction (EF) and severity index (area of atrialized RV+right atrium/functional RV+left ventricle+left atrium). We related these CMR values to cardiopulmonary exercise test measurements. RESULTS Twenty-seven adults (mean age 41 ± 14 years, 70% female) were included. Functional RV end-diastolic volume (EDV) was 150 ± 68 mL/m(2) and atrialized RVEDV was 25 ± 24 mL/m(2). In 17 patients (63%), the functional RVEDV was enlarged (>114 mL/m(2)). Percent predicted peak VO2 for the population was 65 ± 20%. On univariable analysis, peak VO2 was inversely related to atrialized RVEDV (p = 0.011), total RVEDV (p = 0.041), functional RVEDV/left ventricular EDV ratio (p = 0.015) and magnitude of tricuspid valve displacement (p = 0.031). In the multivariate model, the only CMR factor to relate to peak VO2 was atrialized RVEDV (p = 0.011, β = -0.48). No significant correlations were found between CMR measures and heart rate response or ventilatory response to exercise. CONCLUSION In adults with unrepaired Ebstein anomaly, atrialized RV volume was independently related to aerobic capacity. The volume of the atrialized RV is a novel CMR measure which may express severity of disease. Further research is needed to evaluate the prognostic relevance of this exploratory work.