Jouke P. Bokma

Severe tricuspid regurgitation is predictive for adverse events in tetralogy of Fallot

Objective Patients with surgically repaired tetralogy of Fallot (rTOF) may develop functional tricuspid regurgitation (TR) due to annulus dilation. Guidelines suggest pulmonary valve replacement (PVR) in patients with rTOF with progressive TR, but data on clinical outcomes are lacking. Our objective was to determine whether TR was predictive for adverse events after PVR. Methods In this retrospective, multicenter cohort study, patients with rTOF who had undergone PVR after preoperative echocardiographic assessment of TR grade were included. Preoperative and postoperative imaging data and a composite of adverse clinical events (death, sustained ventricular tachycardia, heart failure, or supraventricular tachycardia) were collected. Multivariate Cox hazards regression analysis was used to determine which factors were predictive for adverse events after PVR. Results A total of 129 patients (61% men, age at PVR 32.9±10.4 years) were included. The composite endpoint occurred in 39 patients during 8.4±4.2 years of follow-up. In multivariate analysis, severe preoperative TR (HR 2.49, 95% CI 1.11 to 5.52), right ventricular end-systolic volume (HR 1.02/mL/m2, 95% CI 1.01 to 1.03) and age at PVR (HR 1.07/year, 95% CI 1.04 to 1.09) were predictive for adverse events. Early postoperative TR was not predictive for adverse events (p=0.96). In patients without any risk factor (age >40 years, right ventricular end-systolic volume >90 mL/m2 or severe TR), 5-year event-free survival was 100% as compared with 61% in patients with two or three risk factors. Conclusions In patients with rTOF, severe preoperative TR was predictive for adverse events after PVR. Close surveillance is warranted in these patients irrespective of postoperative TR.

Factors associated with long-term mortality after Fontan procedures: a systematic review.

Background Despite an ageing Fontan population, data on late outcomes are still scarce. Reported outcome measures and determinants vary greatly between studies making comprehensive appraisal of mortality hazard challenging. Methods We conducted a systematic review to evaluate causes and factors associated with late mortality in patients with Fontan circulation. Late mortality was defined as mortality beyond the first postoperative year. Studies were included if they had ≥90 patients or ≥20 late mortalities and/or transplants. Studies with overlapping patients were rationalised to include only the most recent studies to avoid duplication. Results From 28 studies, a total of 6707 patients with an average follow-up time of 8.23±5.42 years was identified. There were 1000 deaths. Causes of late death were reported in 697 cases. The five most common causes were heart/Fontan failure (22%), arrhythmia (16%), respiratory failure (15%), renal disease (12%) and thrombosis/bleeding (10%). Factors associated with late mortality were evaluated and classified into 9 categories. Conclusions Causes and factors associated with late mortality after the Fontan operation are summarised in this study. The presented information will aid in identifying patients at highest risk for mortality and guide our risk stratification efforts in this patient population.

QRS fragmentation is superior to QRS duration in predicting mortality in adults with tetralogy of Fallot

Background Although QRS duration >180 ms has prognostic value in adults with tetralogy of Fallot (TOF), its sensitivity to predict mortality is low. Fragmented QRS complexes, a simple measurement on ECG, are related to myocardial fibrosis and dysfunction in patients with TOF. Our objective was to determine whether QRS fragmentation predicts major outcomes in TOF. Methods This multicentre study included adult patients with TOF from a prospective registry. Notches in the QRS complex in ≥2 contiguous leads on a 12-lead ECG, not related to bundle branch block, were defined as QRS fragmentation, which was classified as none, moderate (≤4 leads) or severe (≥5 leads). The primary and secondary outcomes were all-cause mortality and clinical ventricular arrhythmia, respectively. Results A total of 794 adult patients with TOF (median age 27 years, 55% male; 52% no QRS fragmentation, 32% moderate, 16% severe) were included. During long-term (median 10.4 years) follow-up, 46 (6%) patients died and 35 (4%) patients had ventricular arrhythmias. Overall, 10-year survival was 98% in patients without fragmented QRS complexes, 93% in patients with moderate QRS fragmentation and 81% in patients with severe QRS fragmentation. In multivariable Cox hazards regression analysis, extent of QRS fragmentation (HR: 2.24/class, 95% CI 1.48 to 3.40, p<0.001) remained independently predictive for mortality, whereas QRS duration was not predictive (p=0.85). The extent of QRS fragmentation was also independently predictive for ventricular arrhythmia (HR: 2.00/class, 95% CI 1.26 to 3.16, p=0.003). Conclusions The extent of QRS fragmentation is superior to QRS duration in predicting mortality in adult patients with TOF and may be used in risk stratification.

Value of Cardiovascular Magnetic Resonance Imaging in Noninvasive Risk Stratification in Tetralogy of Fallot

Importance Adults late after total correction of tetralogy of Fallot (TOF) are at risk for major complications. Cardiovascular magnetic resonance (CMR) imaging is recommended to quantify right ventricular (RV) and left ventricular (LV) function. However, a commonly used risk model by Khairy et al requires invasive investigations and lacks CMR imaging to identify high-risk patients. Objective To implement CMR imaging in noninvasive risk stratification to predict major adverse clinical outcomes. Design, Setting, and Participants This multicenter study included 575 adult patients with TOF (4.083 patient-years at risk) from a prospective nationwide registry in whom CMR was performed. This study involved 5 tertiary referral centers with a specialized adult congenital heart disease unit. Multivariable Cox hazards regression analysis was performed to determine factors associated with the primary end point. The CMR variables were combined with the noninvasive components of the Khairy et al risk model, and the C statistic of the final noninvasive risk model was determined using bootstrap sampling. The data analysis was conducted from January to December 2016. Main Outcomes and Measures The composite primary outcome was defined as all-cause mortality or ventricular arrhythmia, defined as aborted cardiac arrest or documented ventricular fibrillation and ventricular tachycardia (lasting ≥30 seconds or recurrent symptomatic). Results Of the 575 patients with TOF, 57% were male, and the mean (SD) age was 31 (11) years. During a mean (SD) follow-up of 7.1 (3.5) years, the primary composite end point occurred in 35 patients, including all-cause mortality in 13 patients. Mean (SD) RV ejection fraction (EF) was 44% (10%), and mean (SD) LV EF was 53% (8%). There was a correlation between RV EF and LV EF (R, 0.36; 95% CI, 0.29-0.44; P < .001). Optimal thresholds for ventricular function (RV EF <30%: hazard ratio, 3.90; 95% CI, 1.84-8.26; P < .001 and LV EF <45%: hazard ratio, 3.23; 95% CI, 1.57-6.65; P = .001) were independently predictive in multivariable analysis. Both thresholds were included in a point-based noninvasive risk model (C statistic, 0.75; 95% CI, 0.63-0.85) and combined with the noninvasive components of the Khairy et al risk model. Conclusions and Relevance In patients with repaired TOF, biventricular dysfunction on CMR imaging was associated with major adverse clinical outcomes. The quantified thresholds (RV EF <30% and LV EF <45%) may be implemented in noninvasive risk stratification.

A propensity score-adjusted analysis of clinical outcomes after pulmonary valve replacement in tetralogy of Fallot

Objective To determine the association of pulmonary valve replacement (PVR) with death and sustained ventricular tachycardia (VT) in patients with repaired tetralogy of Fallot (rTOF). Methods Subjects with rTOF and cardiac magnetic resonance from an international registry were included. A PVR propensity score was created to adjust for baseline differences. PVR consensus criteria were predefined as pulmonary regurgitation >25% and ≥2 of the following criteria: right ventricular (RV) end-diastolic volume >160 mL/m2, RV end-systolic volume >80 mL/m2, RV ejection fraction (EF) <47%, left ventricular EF <55% and QRS duration >160 ms. The primary outcome included (aborted) death and sustained VT. The secondary outcome included heart failure, non-sustained VT and sustained supraventricular tachycardia. Results In 977 rTOF subjects (age 26±15 years, 45% PVR, follow-up 5.3±3.1 years), the primary and secondary outcomes occurred in 41 and 88 subjects, respectively. The HR for subjects with versus without PVR (time-varying covariate) was 0.65 (95% CI 0.31 to 1.36; P=0.25) for the primary outcome and 1.43 (95% CI 0.83 to 2.46; P=0.19) for the secondary outcome after adjusting for propensity and other factors. In subjects (n=426) not meeting consensus criteria, the HR for subjects with (n=132) versus without (n=294) PVR was 2.53 (95% CI 0.79 to 8.06; P=0.12) for the primary outcome and 2.31 (95% CI 1.07 to 4.97; P=0.03) for the secondary outcome. Conclusion In this large multicentre rTOF cohort, PVR was not associated with a reduced rate of death and sustained VT at an average follow-up of 5.3 years. Additionally, there were more events after PVR compared with no PVR in subjects not meeting consensus criteria.

Predicting long-term mortality after Fontan procedures: A risk score based on 6707 patients from 28 studies

BACKGROUND Reported long-term outcome measures vary greatly between studies in Fontan patients making comprehensive appraisal of mortality hazard challenging. We sought to create a clinical risk score to assist monitoring of Fontan patients in the outpatient setting. METHODS A systematic review was conducted to evaluate risk factors for long-term (beyond the first postoperative year) mortality in Fontan patients. Studies were eligible for inclusion if ≥90 patients were included or ≥20 long-term mortalities we reported. Risk factors for long-term mortality were determined. The pooled hazard ratios were used to create components of a clinical score for long-term mortality using meta-analysis techniques. RESULTS Twenty-eight studies were included. The total number of patients was 6707 with an average follow-up of 8.23 ± 5.42 years. There were 1000 deaths. Thirty-five risk factors for late mortality were identified and classified into 9 categories and their relative hazards were used to derive the initial components of a weighted, practical and clinically based Fontan risk score (ranging from 0 to 100). The final score included 8 risk factors: anatomic risk factors, elevated preoperative pulmonary artery pressure, atriopulmonary Fontan, heart failure symptoms, arrhythmia, moderate/severe ventricular dysfunction or atrioventricular valve regurgitation, protein losing enteropathy, and end organ disease (cirrhosis or renal insufficiency). CONCLUSION In patients with Fontan circulation, the influence of readily available risk factors can be quantified in an integer score to predict long-term mortality. Prospective validation and refinement of this risk score will be undertaken.

Effect of Losartan on Right Ventricular Dysfunction Results From the Double-Blind, Randomized REDEFINE Trial (Right Ventricular Dysfunction in Tetralogy of Fallot: Inhibition of the Renin-Angiotensin-Aldosterone System) in Adults With Repaired Tetralogy of Fallot

Background: The effect of angiotensin II receptor blockers on right ventricular (RV) function is still unknown. Angiotensin II receptor blockers are beneficial in patients with acquired left ventricular dysfunction, and recent findings have suggested a favorable effect in symptomatic patients with systemic RV dysfunction. The current study aimed to determine the effect of losartan, an angiotensin II receptor blocker, on subpulmonary RV dysfunction in adults after repaired tetralogy of Fallot. Methods: The REDEFINE trial (Right Ventricular Dysfunction in Tetralogy of Fallot: Inhibition of the Renin-Angiotensin-Aldosterone System) is an investigator-initiated, multicenter, prospective, 1:1 randomized, double-blind, placebo-controlled study. Adults with repaired tetralogy of Fallot and RV dysfunction (RV ejection fraction [EF] <50%) but without severe valvular dysfunction were eligible. Patients were randomly assigned between losartan (150 mg daily) and placebo with target treatment duration between 18 and 24 months. The primary outcome was RV EF change, determined by cardiovascular MRI in intention-to-treat analysis. Results: Of 95 included patients, 47 patients received 150 mg losartan daily (age, 38.0±12.4 years; 74% male), and 48 patients received placebo (age, 40.6±11.4 years; 63% male). Overall, RV EF did not change in patients allocated to losartan (n=42) (44.4±5.1% to 45.2±5.0%) and placebo (n=46) (43.2±6.3% to 43.6±6.9%). Losartan did not significantly improve RV EF in comparison with placebo (+0.51%; 95% confidence interval, –1.0 to +2.0; P=0.50). No significant treatment effects were found on secondary outcomes: left ventricular EF, peak aerobic exercise capacity, and N-terminal pro–brain natriuretic peptide (P>0.30 for all). In predefined subgroup analyses, losartan did not have a statistically significant impact on RV EF in subgroups with symptoms, restrictive RV, RV EF<40%, pulmonary valve replacement, or QRS fragmentation. However, in a post hoc analysis, losartan was associated with improved RV EF in a subgroup (n=30) with nonrestrictive RV and incomplete remodeling (QRS fragmentation and previous pulmonary valve replacement) (+2.7%; 95% confidence interval, +0.1 to +5.4; P=0.045). Conclusions: Losartan had no significant effect on RV dysfunction or secondary outcome parameters in repaired tetralogy of Fallot. Future larger studies may determine whether there might be a role for losartan in specific vulnerable subgroups. Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02010905.Background —The effect of angiotensin II receptor blockers (ARBs) on right ventricular (RV) function is still unknown. ARBs are beneficial in patients with acquired left ventricular (LV) dysfunction and recent findings suggested a favorable effect in symptomatic patients with systemic RV dysfunction. The current study aimed to determine the effect of losartan, an ARB, on subpulmonary RV dysfunction in adults after repair of tetralogy of Fallot (rTOF). Methods —REDEFINE is an investigator-initiated, multicenter, prospective, 1:1 randomized, double-blind, placebo-controlled study. Adults with rTOF and RV dysfunction (RV ejection fraction (EF) Results —Of 95 included patients, 47 patients received 150mg losartan daily (age: 38.0±12.4 years, 74% male), and 48 patients received placebo (age: 40.6±11.4, 63% male). Overall, RV EF did not change in patients allocated to losartan (n=42) (44.4±5.1% to 45.2±5.0%) and placebo (n=46) (43.2±6.3% to 43.6±6.9%). Losartan did not significantly improve RV EF compared to placebo (+0.51%, 95% CI:-1.0, +2.0, p=0.50). No significant treatment effects were found on secondary outcomes: left ventricular EF, peak aerobic exercise capacity, and N-terminal pro brain natriuretic peptide (p>0.30 for all). In predefined subgroup analyses, losartan did not have a statistically significant impact on RV EF in subgroups with: symptoms, restrictive RV, RV EF Conclusions —Losartan had no significant effect on RV dysfunction or secondary outcome parameters in rTOF. Future larger studies may determine whether there might be a role for losartan in specific vulnerable subgroups. Clinical Trial Registration —URL: https://clinicaltrials.gov Unique Identifier: NCT02010905

Individualised prediction of pulmonary homograft durability in tetralogy of Fallot

Background In patients with repaired tetralogy of Fallot (rTOF), multiple reoperations or percutaneous interventions after pulmonary valve replacement (PVR) may be necessary due to limited homograft durability. However, data to guide individualised prediction of homograft durability remain scarce. The aim of this study was to provide risk models for RV to pulmonary artery homograft durability. Methods This retrospective multicentre study included consecutive patients with rTOF who had undergone PVR at an age of >12 years. Homograft dysfunction was defined as at least moderate pulmonary regurgitation (PR) or pulmonary stenosis (PS) (pressure gradient ≥36 mm Hg) as assessed by echocardiography. Reintervention was defined as percutaneous intervention or redo-PVR. Results A total of 153 patients with rTOF were included (62% male, mean age at PVR 31±11 years, pulmonary homograft 96%, follow-up 9.6 years (IQR 5.9, 13.3)). Average freedom from homograft dysfunction and reintervention after 10 years was 74% and 89%, respectively. In multivariable Cox proportional hazards analysis, postoperative PS ≥20 mm Hg (HR 6.52, 95% CI 3.09 to 13.7), postoperative PR ≥ grade 1 (HR 3.13, 95% CI 1.45 to 6.74) and age at PVR <18 years (HR 3.52, 95% CI 1.64 to 7.53) were independently predictive for homograft dysfunction. In patients without any risk factor, 10-year freedom from homograft dysfunction and reintervention was excellent (91% and 96%, respectively) in contrast to patients with ≥2 risk factors (25% and 73%, respectively). Conclusions Individualised prediction of homograft durability in patients with rTOF can be guided by early postoperative echocardiography. In adult patients without early postoperative PS or PR, homograft dysfunction and reintervention are unlikely to occur within 10 years, and follow-up may be less stringent.

Factors associated with coronary artery disease and stroke in adults with congenital heart disease

Objective To determine factors associated with coronary artery disease (CAD) and ischaemic stroke in ageing adult congenital heart disease (ACHD) patients. Methods We performed a multicentre case–control study, using data from the national CONgenital CORvitia (CONCOR) registry to identify ACHD patients within five participating centres. Patients with CAD were matched (1:2 ratio) with ACHD patients without CAD on age, CHD defect group and gender. Patients with ischaemic stroke (or transient ischaemic attack) were matched similarly. Medical charts were reviewed and a standardised questionnaire was used to determine presence of risk factors. Results Of 6904 ACHD patients, a total of 55 cases with CAD (80% male, mean age 55.1±12.4 years) and 56 cases with stroke (46% male, mean age 46.9±15.2) were included and matched with control patients. In multivariable logistic regression analysis, traditional atherosclerotic risk factors (hypertension (OR 2.45; 95% CI 1.15 to 5.23), hypercholesterolaemia (OR 3.99; 95% CI 1.62 to 9.83) and smoking (OR 2.25; 95% CI 1.09 to 4.66)) were associated with CAD. In contrast, these risk factors were not associated with ischaemic stroke. In multivariable analysis, stroke was associated with previous shunt operations (OR 4.20; 95% CI 1.36 to 12.9), residual/unclosed septal defects (OR 2.38; 95% CI 1.03 to 5.51) and left-sided mechanical valves (OR 2.67; 95% CI 1.09 to 6.50). Conclusions Traditional atherosclerotic risk factors were associated with CAD in ACHD patients. In contrast, ischaemic stroke was related to factors (previous shunts, septal defects, mechanical valves) suggesting a cardioembolic aetiology. These findings may inform surveillance and prevention strategies.

Pulmonary Valve Replacement After Repair of Pulmonary Stenosis Compared With Tetralogy of Fallot

Similar to patients with tetralogy of Fallot (TOF), patients born with congenital pulmonary stenosis (PS) may initially require intervention to relieve right ventricular (RV) outflow tract obstruction. As a consequence, patients with both conditions may develop deleterious RV volume overload due to