Aortic disease and interventions in adults with tetralogy of Fallot.

BACKGROUND: Aortic dilation and aortic valve disease are known long-term complication of tetralogy of Fallot (TOF), but the risk of aortic dissection and the indications for prophylactic aortic surgery are unknown in this population. The purpose of this study was to: (1) determine the prevalence of significant aortic valve disease and/or significant aortic aneurysm (AVD-AA); (2) determine the incidence of progressive aortic dilation and aortic dissection in patients with TOF. METHODS: Retrospective review of adults with repaired TOF, and no prior aortic valve/aorta surgery, who had ≥2 measurements of the thoracic aorta >12 months apart, 1990-2017. The aortic root and mid-ascending aorta were measured at the onset of QRS complex from leading edge to leading edge. Significant aortic valve disease was defined as the presence of ≥moderate aortic stenosis and/or ≥moderate aortic regurgitation. Significant aortic aneurysm was defined as aortic root or mid-ascending aorta dimension ≥50 mm. Progressive aortic dilation was defined as increase in aortic dimension ≥2 mm. RESULTS: Of the 453 consecutive patients (37±13 years, men 216 (49%)) in the study, aortic aneurysm was present in 312 (69%) based on normative data; progressive aortic dilation occurred in 40 (9%), and there was no case of aortic dissection. Significant AVD-AA occurred in 52 (12%) patients; and 15 of them (29%) underwent aortic surgery without any surgical mortality. CONCLUSIONS: Although aortic aneurysm was common, progressive aortic dilation was uncommon and aortic dissection did not occur in our patients with TOF with significant aortic aneurysms who did not undergo aortic surgery. This has important clinical implication in deciding the frequency of imaging follow-up and timing of surgical intervention in this population.

Venous congestion and pulmonary vascular function in Fontan circulation: Implications for prognosis and treatment.

BACKGROUND: Elevation in central venous pressure (CVP) plays a fundamental pathophysiologic role in Fontan circulation. Because there is no sub-pulmonary ventricle in this system, CVP also provides the driving force for pulmonary blood flow. We hypothesized that this would make Fontan patients more susceptible to even low-level elevation in pulmonary vascular resistance index (PVRI), resulting in greater systemic venous congestion and adverse outcomes. METHODS: Adult Fontan patients and controls without congenital heart disease undergoing clinical evaluation that included cardiac catheterization and echocardiography were examined retrospectively. Outcomes including all-cause mortality and the development of Fontan associated diseases (FAD, defined as protein losing enteropathy, cirrhosis, heart failure hospitalization, arrhythmia, or thromboembolism) were assessed from longitudinal assessment. RESULTS: As compared to controls (n = 82), Fontan patients (n = 164) were younger (36 vs 45 years, p < 0.001), more likely to be on anticoagulation or antiplatelet therapy, and more likely to have atrial arrhythmia or cirrhosis. There was a strong correlation between CVP and PVRI in the Fontan group (r = 0.79, p < 0.001), but there was no such relationship in controls. Elevated PVRI identified patients at increased risk for FAD (HR 1.92, 95% CI 1.39-2.41, p = 0.01), and composite endpoint of FAD and/or death (HR 1.89, 95% CI 1.32-2.53, p = 0.01) per 1 WU∗m2 increment. CONCLUSIONS: Systemic venous congestion, which is the primary factor in the pathogenesis of FAD and death, is related to even low-level abnormalities in pulmonary vascular function. Multicenter studies are needed to determine whether interventions targeting pulmonary vascular structure and function can improve outcomes in the Fontan population.

Outcomes of hospitalization in adults with Fontan palliation: The Mayo Clinic experience.

The outcomes of hospitalization in the Fontan population have not been specifically studied. The purpose of this study was to describe outcomes of hospitalization (frequency and indications for hospitalization, and in-hospital mortality) in this population and to determine how these outcomes differ from those of other adults with congenital heart disease (CHD). METHODS: This was a retrospective study of adult Fontan patients hospitalized at Mayo Clinic Rochester in 1990-2015. We selected age- and gender-matched control group of patients with repaired CHD and biventricular circulation hospitalized within the study period. RESULTS: A total of 367 Fontan patients (age 31±7 years and 259 [71%] with atriopulmonary Fontan) had 853 hospital admissions in 4 years (58 hospitalizations per 100 patient-years). The most common indications were arrhythmia (n=188, 22%), heart failure (n=169, 20%), and cardiac surgery (n=133, 16%). Overall in-hospital mortality was 4% (n=38), and the highest in-hospital mortality occurred in patients hospitalized for cardiac surgery (n=15, 11%) and heart failure (n=13, 8%). In comparison to the repaired CHD and biventricular circulation group, the Fontan group had more frequent hospitalizations (22 vs 58 per 100 patient-years, P<.001) and higher overall in-hospital mortality (1% vs 5%, P<.001), mortality after cardiac surgery (2% vs 11%, P=.01), and mortality for heart failure-related hospitalizations (2% vs 8%, P=.04). CONCLUSIONS: Adults with Fontan palliation had more frequent hospitalization and in-hospital mortality compared to the rest of the CHD population. Arrhythmia and heart failure were the most common indications for hospitalization. Perhaps optimal management of heart failure and arrhythmia may improve outcomes in this population.

Temporal changes in liver stiffness after Fontan operation: Results of serial magnetic resonance elastography.

BACKGROUND: The relationship between temporal progression of magnetic resonance elastography derived liver stiffness (MRE-LS) and progression of Fontan associated liver disease (FALD) is unknown. To assess this relationship, we hypothesized that progression of MRE-LS correlated with progression FALD severity and clinical outcomes. METHODS: Retrospective review of Fontan patients who had >1 liver MRE, 2010-2016. Annual change in MRE-LS was the quotient of the difference between baseline and subsequent MRE-LS, and the interval between scans. RESULTS: 22 patients were enrolled; median age 29(19-38) years, 14 (64%) males and 10 (46%) with atriopulmonary Fontan. Baseline and subsequent MRE-LS values were 5.4 ±â€¯1.1 kPa and 5.8 ±â€¯0.9 kPa" for clarity, interval between scans was 25 ±â€¯5 months, and annual change in MRE-LS was 0.3 ±â€¯0.2 kPa. Temporal change in MRE-LS correlated with temporal changes in model for end-stage liver disease (MELD) score (r = 0.84, p < 0.001) and model for end-stage liver disease excluding international normalized ratio (MELD-XI) score (r = 0.75, p = 0.001). The study cohort was divided into 2 groups using the mean annual change in MRE-LS as the cut point. Groups A and B comprised of patients with annual increase in MRE-LS ≥0.3 kPa (n = 6) and <0.3 kPa (n = 16) respectively. Composite adverse event endpoint (death, heart-liver transplant listing, palliative care, hospitalization, paracentesis) was more common in Group A (4 of 6, 67%) compared to Group B (3 of 16, 19%), p = 0.13 although this did not reach statistical significance due to small sample size. CONCLUSIONS: Progression of MRE-LS correlated with clinical deterioration as measured by worsening liver disease severity scores and the occurrence of adverse events.

Mechanism for temporal changes in exercise capacity after Fontan palliation: Role of Doppler echocardiography.

BACKGROUND: The objective was to better understand Doppler hemodynamics and exercise capacity in patients with Fontan palliation by delineating the hemodynamic mechanism for temporal changes in their peak oxygen consumption (V̇o2). METHODS: We performed a retrospective review of adult Fontan patients with systemic left ventricle (LV) who underwent serial transthoracic echocardiograms (TTE) and cardiopulmonary exercise tests (CPET) at Mayo Clinic in 2000-2015. TTE and CPET data were used (1) to determine agreement between V̇o2 and Doppler-derived LV function indices (eg, stroke volume index [SVI] and cardiac index [CI]) and (2) to determine agreement between temporal changes in peak V̇o2 and LV function indices. RESULTS: Seventy-five patients (44 men; 59%) underwent 191 pairs of TTE and CPET. At baseline, mean age was 24±3 years, peak V̇o2 was 22.9±4.1 mL/kg/min (63±11 percent predicted), SVI was 43±15 mL/m2, and CI was 2.9±0.9 L/min/m2. Peak V̇o2 correlated with SVI (r=0.30, P<.001) and with CI (r=0.45, P<.001) in the 153 pairs of TTE and CPET in patients without cirrhosis. Temporal changes in percent predicted peak V̇o2 correlated with changes in SVI (r=0.48, P=.005) and CI (r=0.49, P=.004) among the 33 patients without interventions during the study. In the 19 patients with Fontan conversion, percent predicted peak V̇o2 and chronotropic index improved. CONCLUSIONS: Overall, there was a temporal decline in peak V̇o2 that correlated with decline in Doppler SVI. In the patients who had Fontan conversion operation, there was a temporal improvement in peak V̇o2 that correlated with improvement in chronotropic index.

Role of diastolic function indices in the risk stratification of patients with mixed aortic valve disease.

Aims: Determine the role of diastolic function indices in pre-operative and post-operative risk stratification in patients with moderate mixed aortic valve disease (MAVD). Methods and results: A retrospective study was conducted of asymptomatic patients with moderate MAVD (a combination of moderate aortic stenosis and moderate aortic regurgitation) and an ejection fraction of 50% or more who were followed up at Mayo Clinic from 1 January 2004, to 31 December 2013. A pre-requisite for inclusion in the study was assessment of diastolic function involving at least three of the following indices: tissue Doppler early diastolic velocity (e'), mitral inflow early velocity (E), tricuspid regurgitation velocity, and left atrial volume index. Primary endpoints were aortic valve replacement (AVR) or cardiac death while secondary endpoints were cardiovascular adverse events (CAEs) after AVR. We defined CAEs as stroke, heart failure hospitalization, severe left ventricular dysfunction, and cardiac death. There were 214 patients (age 61 ± 8 years, men 146 [68%]) followed for 6.1 ± 2.3 years during which 162 (76%) AVRs and 11 (5%) cardiac deaths occurred. The multivariable risk factors for cardiac death or AVR were relative wall thickness (RWT) > 0.42 [hazard ratio (HR), 1.88 [95% CI, 1.28-2.59]; P = 0.001] and average E/e' >14 (HR, 1.94 [95% CI, 1.29-3.01]; P = 0.02). Freedom from CAE after AVR was significantly lower in the patients with baseline RWT >0.42 or mean E/e' >14 than the other patients: 79% (95% CI 74-83%) vs. 94% (95% CI 89-98%) at 3 years (P = 0.03). Conclusion: The presence of RWT >0.42 or E/e' >14 identifies a high-risk patient subset whose risk for cardiovascular morbidities persists even after AVR.

Early Prosthetic Valve Dysfunction Due to Bioprosthetic Valve Thrombosis: The Role of Echocardiography.

OBJECTIVES: The purpose of this study was to review the institutional practice of surveillance transthoracic echocardiography (TTE) for diagnosing early prosthetic valve dysfunction (PVD). BACKGROUND: Bioprosthetic valve thrombosis (BPVT) is an important cause of PVD, and guidelines do not recommend routine TTE during the first 5 years after valve implantation. METHODS: The authors performed a retrospective case-control study of all suspected (imaging diagnosis) or confirmed (histopathological diagnosis) cases of BPVT from January 1997 through December 2016. Patients were matched 1:2 (age, sex, prosthesis position) to patients whose prostheses were explanted because of structural failure (SF). PVD was defined as a 50% increase above baseline gradient at valve implantation and classified as early (≤5 years) or late (>5 years) after implantation. RESULTS: There were 94 BPVT (51 suspected, 43 confirmed) and 188 SF cases; patient age 61 ± 9 years; men 61 (65%). The prosthesis positions were aortic 56%; mitral 26%; tricuspid 15%; and pulmonary 3%. Early PVD was more common in the BPVT versus SF group: 83 of 94 (88%) versus 20 of 188 (11%) (p < 0.001). Time from implantation to PVD was shorter for BPVT than SF: 26 months (interquartile range [IQR]: 12 to 43 months) versus 74 months (IQR: 48 to 102 months) (p < 0.001). At the initial PVD diagnosis, 81% of BPVT and 90% of SF patients were asymptomatic. However, BPVT patients had rapid symptomatic deterioration, requiring intervention sooner after PVD diagnosis: 6 months (IQR: 4 to 7 months) versus 51 months (IQR: 22 to 55 months) (p < 0.001). CONCLUSIONS: Most patients with PVD due to BPVT were asymptomatic at initial diagnosis, which was made based on routine surveillance TTE, often performed before 5 years. BPVT, an acute disease process, requires timely diagnosis because patient conditions rapidly deteriorate. Further studies are needed to determine whether routine surveillance TTE should be considered for patients with bioprosthetic valves to identify pre-symptomatic features of BPVT in order to provide effective, appropriate therapy.

Role of Doppler echocardiography for cardiac output assessment in Fontan patients.

BACKGROUND: To determine (1) correlation between Doppler stroke volume index (SVI) and cardiac magnetic resonance imaging (CMRI) SVI and (2) association between Doppler SVI and Fontan-associated diseases (FAD) and Fontan failure. METHODS: Review of Fontan patients who underwent same-day CMRI and transthoracic echocardiography (TTE), 2005 to 2015. We defined FAD as cardiac thrombus, protein-losing enteropathy, arrhythmia, and hospitalization for heart failure. Fontan failure was defined as Fontan conversion or revision, heart transplantation or listing, or death. RESULTS: Fifty-three patients with systemic left ventricle (LV) underwent 86 sets of TTE/CMRI. Mean (SD) age 31 (6) years. SVI (45 [16] vs 42 [13] mL/m2), CI (3.0 [1.1] vs 2.8 [0.8] L min-1 m-2), and ejection fraction (53 [4]% vs 51 [5]%) were similar for both modalities (P>.05 for all). Doppler SVI correlated with CMRI (r=0.68; P<.001). Sixteen patients had cirrhosis, and these patients had a higher CI (3.9 [0.9] vs 2.8 [1.0] L min-1 m-2; P<.01). Among the 37 patients without cirrhosis, Doppler SVI <39 mL/m2 was associated with FAD (odds ratio [OR], 2.11; 95% confidence limit, 1.26-3.14; P=.02); Fontan failure was more common in patients with CI was <2.5 L min-1 m-2 (3/9 [33%] vs 0/28 [0%], P=.01). Another 11 patients with systemic right ventricle (RV) underwent 17 sets of TTE/CMRI, mean (SD) age 17 (3) years, and CMRI SVI also correlated with Doppler SVI (r=0.75; P<.001). CONCLUSION: Doppler SVI correlated with CMRI SVI in patients with systemic LV and systemic RV. The association between output measures (SVI and CI) and FAD were seen only in single LV patients (single RV patients not assessed for this outcome due to small numbers). An association between low Doppler CI and Fontan failure was suggested in a small number of single LV patients.

Outcomes of cardiac pacing in adult patients after a Fontan operation.

BACKGROUND: Cardiac pacing can be challenging after a Fontan operation, and limited data exist regarding pacing in adult Fontan patients. The objectives of our study were to determine risk factors for pacing and occurrence of device-related complications (DRCs) and pacemaker reinterventions. METHODS: We performed a retrospective review of Fontan patients from 1994 through 2014. We defined DRCs as lead failure, lead recall, cardiac perforation, lead thrombus/vegetation, or device-related infection, and cardiovascular adverse events (CAEs) as venous thrombosis, stroke, death, or heart transplant. Pacemaker reintervention was defined as lead failure or recall. RESULTS: Of 439 patients, 166 (38%) had pacemakers implanted (79 during childhood; 87, adulthood); 114 patients (69%) received epicardial leads initially, and 52 (31%), endocardial leads. Pacing was initially atrial in 52 patients (31%); ventricular, 30 (18%); or dual chamber, 84 (51%). There were 37 reinterventions (1.9% per year) and 48 DRCs (2.4% per year). Pacemaker implantation during childhood was a risk factor for DRCs (hazard ratio, 2.01 [CI, 1.22-5.63]; P = .03). There were 70 CAEs (venous thrombosis, 5; stroke, 11; transplant, 8; and death, 46), yielding a rate of 3.5% per year. DRCs, CAEs, and reintervention rates were comparable for patients with epicardial or endocardial leads. CONCLUSIONS: More than one-third of adult Fontan patients referred to Mayo Clinic had pacemaker implantation. Epicardial leads were associated with high rate of pacemaker reinterventions but similar DRC rates in comparison to endocardial leads.

Prevalence and predictors of intracranial aneurysms in patients with bicuspid aortic valve.

OBJECTIVE: To determine the prevalence and outcomes of intracranial aneurysm (IA) in patients with bicuspid aortic valve (BAV). METHODS: Retrospective review of patients with BAV who underwent brain MR angiography at the Mayo Clinic from 1994 to 2013. RESULTS: There were 678 patients included in this study-mean age 57±13 years, men 480 (71%), mean follow-up 10±3 years (5913 patient-years). Coarctation of aorta (COA) was present in 154 (23%) patients.There were 59 IAs identified in 52 of 678 patients (7.7%). IA was present in 20/154 patients (12.9%) with COA and 32/524 patients (5.7%) without COA (p<0.001). For the patients without COA, female gender and right-left cusp fusion were risks factors for IA in women after adjustment for all potential variables (HR 1.76, CI 1.31 to 2.68, p=0.03). There was no significant trend in the risk for IA across age tertiles: age ≤40 years versus 41-60 years (HR 1.19, p=0.34), and age 41-60 years versus 61-80 years (HR 1.06, p=0.56).Among the 52 patients with IA, enlargement occurred in three patients (6%), rupture in two patients (4%) and four patients (8%) underwent coil embolisation. For the 626 patients without IA at baseline, no patient developed IA over 7±2 years of imaging follow-up. CONCLUSIONS: BAV is associated with a higher prevalence of IA compared to the general population, and this risk is higher in patients with COA, right-left cusp fusion and female gender.

Predictors of procedural complications in adult Fontan patients undergoing non-cardiac procedures.

OBJECTIVE: Limited data exist regarding the outcomes of non-cardiac procedures (NCPs) in adult patients after Fontan operations (Fontan patients). METHODS: To compare procedural outcomes after NCPs in Fontan patients with outcomes for two matched control groups: patients with repaired congenital heart disease and biventricular circulation (CHD-BiV) and patients with no heart disease (NHD). We defined cyanosis as oxygen saturation <90% and procedural hypoxia as saturation <80% or a decrease in saturation >10% from baseline. RESULTS: There were 538 NCPs in 154 Fontan patients (mean age, 30 years) performed in 1990-2015. Sedation and anaesthesia types were monitored anaesthesia care (256,48%), general anaesthesia (51,9%), minimal sedation (105,20%), local anaesthesia (75,14%) and regional anaesthesia (51,9%). Ninety-three complications occurred in 79 procedures (15%) and included arrhythmia requiring intervention (9), hypotension (14), bradycardia (8), hypoxia (38), heart failure requiring intravenous diuretics (2), acute kidney injury (3), bleeding requiring blood transfusion (1), unplanned procedures for dialysis catheter placement (2), readmission (2), unplanned hospitalisation for hypoxia (8) and unplanned transfer to intensive care unit (1). Baseline cyanosis was the only multivariable risk factor for complications (HR, 1.87 (95% CI 1.14 to 3.67), p=0.04). Procedural complications were more common in the Fontan group (18%) than in the CHD-BiV (5%) and NHD groups (1.4%) (p=0.001). CONCLUSIONS: Complications after NCPs were more common in Fontan patients, and baseline cyanosis was a risk factor for complications. All-cause mortality was low and may be related to the multidisciplinary care approach used for Fontan patients at our centre.

Outcomes in adult Fontan patients with atrial tachyarrhythmias.

BACKGROUND: The optimal management strategy for atrial tachyarrhythmia in the Fontan population is unknown. METHODS: Retrospective review of 264 adult Fontan patients with atrial tachyarrhythmia evaluating 3 clinically adopted scenarios: antiarrhythmic drug (AAD) therapy, catheter ablation (CA), and Fontan conversion (FC). These patients were followed up at Mayo Clinic from 1994 to 2014. The study objective was to compare freedom from atrial tachyarrhythmia recurrence (AR) and occurrence of composite adverse events (stroke, heart failure hospitalization, death, or heart transplant) between treatment groups. RESULTS: The age of atrial tachyarrhythmia onset was 25 ± 4 years, time from Fontan operation was 13 ± 6 years, follow-up was 74 ± 18 months, atriopulmonary Fontan was 215 (81%), and atrial flutter/intra-atrial reentry tachycardia was 173 (65%). In those managed with AAD (n = 110), freedom from AR was 7% at 60 months. Catheter ablation (n = 31) was associated with an acute procedural success of 94%, and freedom from AR was 41% at 60 months. Fontan conversion (n = 33) resulted in a perioperative mortality of 3%, and freedom from AR was 51% at 60 months. Fontan conversion and CA were similar with regard to AR (P = .14) and significantly better compared with AAD (P < .0001). Adverse events were found to occur more frequently in the patients with AR (P < .0001) and the patients treated with AAD only (P < .0001). CONCLUSIONS: Catheter ablation and FC operations are associated with less recurrence of atrial tachyarrhythmia compared with AAD. Atrial tachyarrhythmias are more likely to recur in patients with a longer history of the arrhythmia and are associated with more adverse events. Early referral to a specialty center for these interventions should be considered.

Cardiopulmonary exercise test in adults with prior Fontan operation: The prognostic value of serial testing.

BACKGROUND: The purpose of the study was to determine the role of cardiopulmonary exercise test (CPET) indices in predicting cardiovascular adverse events (CAEs) in patients with Fontan palliation. CAE was defined as death or cardiac surgery. METHODS: Retrospective review of adult Fontan patients who had treadmill CPET at Mayo Clinic, 1994-2013. Patients with loss of follow-up defined as ≥2years without clinical follow-up were excluded. The results of serial CPETs were reviewed, and patients with CPETs meeting the following criteria were selected for analysis: maximum effort on serial CPETs, minimum of 3-year interval between CPETs, and absence of CAE between CPETs. RESULTS: A total of 145 patients met inclusion criteria for the study; age at baseline CPET was 24±3years; age at Fontan operation was 11±5years; and 91 (63%) were males. Baseline peak oxygen consumption (VO2) was 22.7±5.4ml/kg/min (63±11% predicted), peak heart rate was 135±31beats per minute, and oxygen saturation at peak exercise was 86±7%. Serial CPETs were performed in 71/145 patients (49%); mean duration between CPETs was 3.8±0.3years. The % predicted peak VO2 decreased by 1.7±0.9 percentage points/year. CAE (deaths n=22; cardiac surgery n=45) occurred in 54/145 patients (37%) within 8±3years. Decline in % predicted peak VO2≥3 percentage points/year was the only predictor of 5-year risk of CAE (HR 1.86, 95% CI 1.11-3.48, P=0.02). CONCLUSIONS: Serial CPET is prognostic of CAE in the adult Fontan population, and can be used to risk stratify these patients.

Outcomes of Direct Current Cardioversion in Adults With Congenital Heart Disease.

Few data exist on direct current cardioversion (DCCV) in adult patients with congenital heart disease (CHD). This is a retrospective case-control study of 279 adults with CHD and 279 adults without CHD (control group) who had elective DCCV for atrial arrhythmias at Mayo Clinic, 2001 to 2013. Control patients were matched by gender and arrhythmia type. The objective was to compare DCCV procedural failure (failure to terminate the presenting arrhythmia) and arrhythmia recurrence (AR). In the CHD group (mean age 55 ± 20 years; men 166 [59%]), the most common diagnosis was Fontan palliation (61; 22%). Transesophageal echocardiography was performed before DCCV in 216 patients (77%); 162 (58%) had atrial flutter, and 117 (42%) had atrial fibrillation. Procedural failure and AR between the case and the control groups were more common in the CHD group (14% vs 7%, p = 0.01) and (83% vs 66% at 60 months, p = 0.001) respectively. There were no deaths or thromboembolic complications. The multivariable risk factors for procedural failure were Fontan palliation and spontaneous echocardiographic contrast; the risk factors for AR were Fontan palliation and atrial fibrillation. When patients with Fontan palliation were excluded from the analysis, the outcome of DCCV (failure and recurrence rates) was similar for the CHD and non-CHD groups despite the age difference between the cohorts. In conclusion, the present study showed that DCCV outcomes were similar for CHD and non-CHD patients, with the exception of patients with Fontan palliation.