Impact of heart failure on reoperation in adult congenital heart disease: An innovative machine learning model

OBJECTIVES

The study objectives were to evaluate the association between preoperative heart failure and reoperative cardiac surgical outcomes in adult congenital heart disease and to develop a risk model for postoperative morbidity/mortality.

METHODS

Single-institution retrospective cohort study of adult patients with congenital heart disease undergoing reoperative cardiac surgery between January 1, 2010, and March 30, 2022. Heart failure defined clinically as preoperative diuretic use and either New York Heart Association Class II to IV or systemic ventricular ejection fraction less than 40%. Composite outcome included operative mortality, mechanical circulatory support, dialysis, unplanned noncardiac reoperation, persistent neurologic deficit, and cardiac arrest. Multivariable logistic regression and machine learning analysis using gradient boosting technology were performed. Shapley statistics determined feature influence, or impact, on model output.

RESULTS

Preoperative heart failure was present in 376 of 1011 patients (37%); those patients had longer postoperative length of stay (6 [5-8] vs 5 [4-7] days, P < .001), increased postoperative mechanical circulatory support (21/376 [6%] vs 16/635 [3%], P = .015), and decreased long-term survival (84% [80%-89%] vs 90% [86%-93%]) at 10 years (P = .002). A 7-feature machine learning risk model for the composite outcome achieved higher area under the curve (0.76) than logistic regression, and ejection fraction was most influential (highest mean |Shapley value|). Additional risk factors for the composite outcome included age, number of prior cardiopulmonary bypass operations, urgent/emergency procedure, and functionally univentricular physiology.

CONCLUSIONS

Heart failure is common among adult patients with congenital heart disease undergoing cardiac reoperation and associated with longer length of stay, increased postoperative mechanical circulatory support, and decreased long-term survival. Machine learning yields a novel 7-feature risk model for postoperative morbidity/mortality, in which ejection fraction was the most influential.

Characteristics and Outcomes of a Single-Centre Cohort of Adult Congenital Heart Disease Patients Referred for Heart Transplant

BACKGROUND

Adult congenital heart disease (ACHD) services increasingly encounter heart failure (HF) in the ageing ACHD population. Optimal timing of referral for heart transplant (HTx) evaluation in this heterogeneous population is complex and ill-defined. We aim to outline the characteristics and outcomes of ACHD patients referred for HTx from a large Australian ACHD centre.

METHOD

Retrospective review of ACHD patients referred for HTx from a primary ACHD centre (1992-2021). Database analysis of patient demographics, characteristics, wait-listing, and transplantation outcomes was performed.

RESULTS

A total of 45 patients (mean age 37±9.9 years old; 69% male) were referred for HTx with a mean follow-up of 5.9±6.3 years. Of these, 22 of 45 (49%) were listed and transplanted, including one heart-lung transplant. The commonest diagnosis was dextro-transposition of the great arteries (13/45, 29%). Most patients, 33 of 45 (73.3%) had undergone at least one cardiac surgery in childhood. Indications for HTx referral included HF in 34 of 45 (75%), followed by pulmonary hypertension in 7 of 45 (11%). Median transplant wait-list time was 145 days (interquartile range, 112-256). Of the 23 patients not wait-listed, the reasons included clinical stability in 13 of 45 (29%), psychosocial factors in 2 of 45 (4.4%) and prohibitive surgical risk, including multiorgan dysfunction, in 8 of 45 (17.7%). Transplant was of a single organ in most, 21 of 22 (95.5%). Overall mortality was 5 of 22 (22.7%) in those after HTx, and 14 of 23 (60.9%) in those not listed (p=0.0156).

CONCLUSIONS

Increasingly, ACHD patients demonstrate the need for advanced HF treatments. HTx decision-making is complex, and increased mortality is seen in those not wait-listed. Ultimately, the referral of ACHD patients for HTx is underpinned by local decision-making and experience, wait-list times and outcomes.

Coarctation of Aorta With Tricuspid Aortic Valve Is Not Associated With Ascending Aortic Aneurysm

BACKGROUND

Aortic aneurysm is common in patients with coarctation of aorta (COA), but it is unclear whether the risk of aortic aneurysms is due to COA or related to the presence of other risk factors such as bicuspid aortic valve (BAV) and hypertension.

OBJECTIVES

The purpose of this study was to assess the relationship among COA, BAV, and thoracic aortic aneurysms.

METHODS

A total of 867 patients with COA (COA group) were matched 1:1:1 to 867 patients with isolated BAV (BAV group) and 867 patients without structural heart disease (SHD) (no-SHD group). The COA group was further subdivided into a COA+BAV subgroup (n = 304 [35%]), and COA with tricuspid aortic valve (TAV) (COA+TAV subgroup [n = 563 (65%)]). Aortic dimensions were assessed at baseline and at 3, 5, and 7 years.

RESULTS

Compared with the no-SHD group, the COA+BAV subgroup had larger aortic root diameter (37 mm [Q1-Q3: 30-43 mm] vs 32 mm [Q1-Q3: 27-35 mm]; P < 0.001) and mid ascending aorta dimeter (34 mm [Q1-Q3: 29-40 mm] vs 28 mm [Q1-Q3: 24-31 mm]; P = 0.008). Similarly, the BAV group had larger aortic root diameter (37 mm [Q1-Q3: 30-42 mm] vs 32 mm [Q1-Q3: 27-35 mm]; P < 0.001), and mid ascending aorta dimeter (35 mm [Q1-Q3: 30-40 mm] vs 28 mm [Q1-Q3: 24-31 mm]; P < 0.001). Compared with the COA+TAV subgroup, the COA+BAV subgroup and BAV group were associated with larger aortic root and mid ascending aorta diameter at baseline and follow-up. The risk of acute aortic complications was low in all groups.

CONCLUSIONS

These findings suggest that BAV (and not COA) was associated with ascending thoracic aorta dimensions, and that patients with COA+TAV were not at a greater risk of developing ascending aortic aneurysms as compared with patients without SHD.

Hot-snare assisted percutaneous mechanical aspiration of a calcified amorphous tumor

A 24-year-old female with history of an atrial septal defect post-patch closure (bovine pericardium) presented 4 years postoperative with an incidentally identified mass originating from the septal patch .

Exercise catheterization in adults post-Fontan with normal and abnormal haemodynamic criteria: Insights into normal Fontan physiology

AIM

The normal (i.e. expected) haemodynamics in adults post-Fontan remain poorly delineated. Moreover, the definitions of elevated exercise pulmonary artery (PA) and PA wedge pressure (PAWP) for this population have not been described.

METHODS AND RESULTS

Seventy-two adults post-Fontan undergoing exercise catheterization were categorized into abnormal (Group I, n = 59; defined as resting mean PA ≥14 mmHg and/or PAWP ≥12 mmHg, ΔPAWP/Δsystemic flow [Qs] >2 mmHg/L/min, and/or ΔPA/Δpulmonary flow >3 mmHg/L/min) and normal (Group II, n = 13) haemodynamics. Thirty-nine patients with non-cardiac dyspnoea (NCD) were included as controls. There was no difference in exercise arterial oxygen saturation (87% [81-92] vs. 89% [85-93], p = 0.29), while exercise PA pressure (27 [23-31] vs. 16 [14.5-19.5] mmHg, p < 0.001) and PAWP were higher (21 [18-28] vs. 12 [8-14] mmHg, p < 0.001) in Group I. At peak exercise, Group I had lower heart rate (97 [81-120] vs. 133 [112.5-147.5] bpm, p < 0.001) and Qs response (67.3 [43.8-93.1] vs. 105.9 (82-118.5) % predicted, p < 0.001) than Group II. Exercise superior vena cava pressures were higher (16 [14-22.5] vs. 5.5 [3-7.3] mmHg, p < 0.001) and arterial oxygen saturation lower (89% [85-93] vs. 97% [96-98], p < 0.001) in Group II compared to NCD, while no differences in PAWP, stroke volume index, heart rate, or Qs response were seen. If defined as two standard deviations above mean values for Group II, elevated PAWP and mean PA pressure post-Fontan would correspond to 20.6 mmHg and 25.8 mmHg, respectively.

CONCLUSION

PAWP >20 mmHg and mean PA pressure >25 mmHg could be used to define elevated values during exercise in adults post-Fontan. The major discrepancy in exercise haemodynamics among Group II compared to controls appears to be the degree of systemic venous hypertension and arterial desaturation.

Right Heart Reverse Remodeling and Prosthetic Valve Function After Transcatheter vs Surgical Pulmonary Valve Replacement

BACKGROUND

There are limited data about postprocedural right heart reverse remodeling and long-term prosthesis durability after transcatheter pulmonary valve replacement (TPVR) and how these compare to surgical pulmonary valve replacement (SPVR).

OBJECTIVES

This study sought to compare right heart reverse remodeling, pulmonary valve gradients, and prosthetic valve dysfunction after TPVR vs SPVR.

METHODS

Patients with TPVR were matched 1:2 to patients with SPVR based on age, sex, body surface area, congenital heart lesion, and procedure year. Right heart indexes (right atrial [RA] reservoir strain, RA volume index, RA pressure, right ventricular [RV] global longitudinal strain, RV end-diastolic area, and RV systolic pressure) were assessed at baseline (preintervention), 1 year postintervention, and 3 years postintervention. Pulmonary valve gradients were assessed at 1, 3, 5, 7, and 9 years postintervention.

RESULTS

There were 64 and 128 patients in the TPVR and SPVR groups, respectively. Among patients with TPVR, 46 (72%) and 18 (28%) received Melody (Medtronic) vs SAPIEN (Edwards Lifesciences) valves, respectively. The TPVR group had greater postprocedural improvement in RA reservoir strain and RV global longitudinal strain at 1 and 3 years. The TPVR group had a higher risk of prosthetic valve dysfunction mostly because of a higher incidence of prosthetic valve endocarditis compared to SPVR but a similar risk of pulmonary valve reintervention because some of the patients with endocarditis received medical therapy only. Both groups had similar pulmonary valve mean gradients at 9 years postintervention.

CONCLUSIONS

These data suggest a more favorable right heart outcome after TPVR. However, the risk of prosthetic valve endocarditis and prosthetic valve dysfunction remains a major concern.

Diagnostic and Prognostic Role of Left Ventricular Strain Imaging in Adults with Coarctation of aorta

The relative diagnostic and prognostic performance of left ventricular (LV) global longitudinal strain (LVGLS) compared with LV ejection fraction (LVEF) and the role of LVGLS for detecting the early stages of LV systolic dysfunction in adults with repaired coarctation of the aorta are unknown. This study aimed to address these knowledge gaps. We used a retrospective cohort study of adults with repaired coarctation of the aorta who underwent transthoracic echocardiogram (2003 to 2020). LV systolic function was assessed using LVEF (derived from volumetric analysis) and LVGLS (derived from speckle-tracking echocardiography). Of the 795 patients (age 36 ± 14 years), the mean LVEF and LVGLS were 62 ± 11% and 21 ± 4%, respectively. The prevalence of LV systolic dysfunction was higher when assessed using LVGLS than using LVEF (20% vs 6%, p <0.001). Of 795 patients, 94 (12%) patients died, of which 75 (9%) died from cardiovascular causes. LVGLS provided more robust prognostic power in predicting the all-cause mortality than LVEF, as evidenced by a higher C-statistic (0.743, 95% confidence interval 0.730 to 0.755 vs 0.782, 95% confidence interval 0.771 to 0.792, p <0.001). Furthermore, patients with normal LVEF in the setting of reduced LVGLS had a higher risk of all-cause mortality (than patients with normal LVGLS and LVEF) and were at risk for a temporal decrease in LVEF during follow-up. These findings suggest that the use of LVGLS for risk stratification can help identify high-risk patients and provide opportunities for interventions, which would, in turn, improve clinical outcomes. Further studies are required to empirically test these postulates.

Mortality and Morbidity of Heart Failure Hospitalization in Adult Patients With Congenital Heart Disease

BACKGROUND

Little is known about outcomes following heart failure (HF) hospitalization among adults with congenital heart disease (CHD) in the United States. We aim to compare the outcomes of HF versus non-HF hospitalizations in adults with CHD.

METHODS AND RESULTS

Using a national deidentified administrative claims data set, patients with adult congenital heart disease (ACHD) hospitalized with and without HF (ACHDHF+, ACHDHF-) were characterized to determine the predictors of 90-day and 1-year mortality and quantify the risk of mortality, major adverse cardiac and cerebrovascular events, and health resource use. Cox proportional hazard regression was used to compare ACHDHF+ versus ACHDHF- for risk of events and health resource use. Of 26 454 unique ACHD admissions between January 1, 2010 and December 31, 2020, 5826 (22%) were ACHDHF+ and 20 628 (78%) were ACHDHF-. The ACHD HF+ hospitalizations increased from 6.6% to 14.0% (P<0.0001). Over a mean follow-up period of 2.23 ± 2.19 years, patients with ACHDHF+ had a higher risk of mortality (hazard ratio [HR], 1.86 [95% CI, 1.67-2.07], P<0.001), major adverse cardiac and cerebrovascular events (HR, 1.73 [95% CI, 1.63-1.83], P<0.001) and health resource use including rehospitalization (HR, 1.09 [95% CI, 1.05-1.14], P<0.001) and increased postacute care service use (HR, 1.56 [95% CI, 1.32-1.85], P<0.001). Cardiology clinic visits within 30 days of hospital admission were associated with lower 90-day and 1-year all-cause mortality (odds ratio [OR], 0.62 [95% CI, 0.49-0.78], P<0.001; OR, 0.69 [95% CI, 0.58-0.83], P<0.001, respectively).

CONCLUSIONS

HF hospitalization is associated with increased risk of mortality and morbidity with high health resource use in patients with ACHD. Recent cardiology clinic attendance appears to mitigate these risks.

Systemic Atrioventricular Valve Surgery in Patients With Congenitally Corrected Transposition of the Great Vessels

BACKGROUND

Limited data exist regarding the long-term outcomes of systemic atrioventricular valve (SAVV) intervention (morphologic tricuspid valve) in congenitally corrected transposition (ccTGA).

OBJECTIVES

The goal of this study was to evaluate the mid- and long-term outcomes of SAVV surgery in ccTGA.

METHODS

We performed a retrospective review of 108 ccTGA patients undergoing SAVV surgery from 1979 to 2022. The primary outcome was a composite endpoint of mortality, cardiac transplantation, or ventricular assist device implantation. The secondary outcome was long-term systemic right ventricular ejection fraction (SVEF). Cox proportional hazard and linear regression models were used to analyze survival and late SVEF data.

RESULTS

The median age at surgery was 39.5 years (Q1-Q3: 28.8-51.0 years), and the median preoperative SVEF was 39% (Q1-Q3: 33.2%-45.0%). Intrinsic valve abnormality was the most common mechanism of SAVV regurgitation (76.9%). There was 1 early postoperative mortality (0.9%). Postoperative complete heart block occurred in 20 patients (18.5%). The actuarial 5-, 10-, and 20-year freedom from death or transplantation was 92.4%, 79.1%, and 62.9%. The 10- and 20-year freedom from valve reoperation was 100% and 93% for mechanical prosthesis compared with 56.6% and 15.7% for bioprosthesis (P < 0.0001). Predictors of postoperative mortality were age at operation (P = 0.01) and preoperative SVEF (P = 0.04). Preoperative SVEF (P < 0.001), complex ccTGA (P = 0.02), severe SAVV regurgitation (P = 0.04), and preoperative creatinine (P = 0.003) were predictors of late postoperative SVEF.

CONCLUSIONS

SAVV surgery remains a valuable option for the treatment of patients with ccTGA, with low early mortality and satisfactory long-term outcomes, particularly in those with SVEF ≥40%. Timely referral and accurate patient selection are the keys to better long-term outcomes.

Risk factors and early outcomes of repeat sternotomy in 1960 adults with congenital heart disease: A 30-year, single-center study

OBJECTIVE

Patients with congenital heart disease (CHD) increasingly live into adulthood, often requiring cardiac reoperation. We aimed to assess the outcomes of adults with CHD (ACHD) undergoing repeat sternotomy at our institution.

METHODS

Review of our institution's cardiac surgery database identified 1960 ACHD patients undergoing repeat median sternotomy from 1993 to 2023. The primary outcome was early mortality, and the secondary outcome was a composite end point of mortality and significant morbidity. Univariable and multivariable logistic regression models were used to determine factors independently associated with outcomes.

RESULTS

Of the 1960 ACHDs patient undergoing repeat sternotomy, 1183 (60.3%) underwent a second, third (n = 506, 25.8%), fourth (n = 168, 8.5%), fifth (n = 70, 3.5%), and sixth sternotomy or greater (n = 33, 1.6%). CHD diagnoses were minor complexity (n = 145, 7.4%), moderate complexity (n = 1380, 70.4%), and major complexity (n = 435, 22.1%). Distribution of procedures included valve (n = 549, 28%), congenital (n = 625, 32%), aortic (n = 104, 5.3%), and major procedural combinations (n = 682, 34.7%). Overall early mortality was 3.1%. Factors independently associated with early mortality were older age at surgery, CHD of major complexity, preoperative renal failure, preoperative ejection fraction, urgent operation, and postoperative blood transfusion. In addition, sternotomy number and bypass time were independently associated with the composite outcome.

CONCLUSIONS

Despite the increase in early mortality with sternotomy number, sternotomy number was not independently associated with early mortality but with increased morbidity. Improvement strategies should target factors leading to urgent operations, early referral, along with operative efficiency including bypass time and blood conservation.

Clinical Outcomes of Percutaneous Fontan Stenting in Adults

BACKGROUND

Fontan pathway stenosis is a well-known complication after palliation. Percutaneous stenting is effective for angiographic/hemodynamic relief of Fontan obstruction, but its clinical impact in adults remains unknown.

METHODS

This was a retrospective cohort of 26 adults undergoing percutaneous stenting for Fontan obstruction from 2014 to 2022. Procedural details, functional capacity, and liver parameters were reviewed at baseline and during follow-up.

RESULTS

Median age was 22.5 years (interquartile range [IQR] 19-28.8 y); 69% were male. After stenting, Fontan gradient significantly decreased (2.0 ± 1.9 vs 0 [IQR 0-1] mm Hg; P < 0.005), and minimal Fontan diameter increased (11.3 ± 2.9 vs 19.3 [IQR 17-20] mm; P < 0.001). One patient developed acute kidney injury periprocedurally. During a follow-up of 2.1 years (IQR 0.6-3.7 y), 1 patient had thrombosis of the Fontan stent and 2 underwent elective Fontan re-stenting. New York Heart Association functional class improved in 50% of symptomatic patients. Changes in functional aerobic capacity on exercise testing were directly related to pre-stenting Fontan gradient (n = 7; r = 0.80; P = 0.03) and inversely related to pre-stenting minimal Fontan diameter (r = -0.79; P = 0.02). Thrombocytopenia (platelet count < 150 109/L) was present in 42.3% of patients before and in 32% after the procedure (P = 0.08); splenomegaly (spleen size > 13 cm) was present in 58.3% and 58.8% (P = 0.57), respectively. Liver fibrosis (aspartate transaminase to platelet ratio index and Fibrosis-4) scores were unchanged after the procedure compared with baseline.

CONCLUSIONS

Percutaneous stenting in adults is safe and effective in relieving Fontan obstruction, resulting in subjective improvement in functional capacity in some. A subset of patients demonstrated improvement in markers of portal hypertension, suggesting that Fontan stenting could improve Fontan-associated liver disease in select individuals.

Effects of inhaled nitric oxide on Fontan hemodynamics in adults

The pulmonary vasculature plays a pivotal role in the nonpulsatile systemic venous return post-Fontan palliation. Elevated pulmonary vascular resistance index (PVRi) carries a worse prognosis post-Fontan, but the benefits of pulmonary vasodilators remain controversial. Moreover, the potential for worsening ventricular filling pressures with pulmonary vasodilation has been highlighted. We reviewed our experience with inhaled nitric oxide (iNO) administration during cardiac catheterization in 30 adults (age 32.7 ± 8.5 years) post-Fontan. The main findings of the study are: (1) iNO decreased pulmonary artery pressures, transpulmonary gradient, and PVRi without increasing pulmonary artery wedge pressure, (2) cardiac index was unchanged with iNO, and (3) different from acquired left heart disease, iNO did not result in further elevations in pulmonary artery wedge pressure in those with elevated ventricular filling pressures. iNO administration in adults post-Fontan was safe; whether baseline PVRi and response to iNO could be used to predict response to pulmonary vasodilators post-Fontan requires further investigation.

Clinical benefits of angiotensin receptor-Neprilysin inhibitor in adults with congenital heart disease

BACKGROUND

There are limited data about the clinical benefits of angiotensin receptor-neprilysin inhibitor (ARNI) in adults with congenital heart disease (CHD). The purpose of the study was to assess the clinical benefits (chamber function and heart failure indices) of ARNI in adults with CHD.

METHOD

In this retrospective cohort study, we compared the temporal change in chamber function and heart failure indices between 35 patients that received ARNI for >6 months, and a propensity matched control group (n = 70) of patients that received angiotensin converting enzyme inhibitor or angiotensin-II receptor blocker (ACEI/ARB) within the same period.

RESULTS

Of the 35 patients in the ARNI group, 21 (60%) had systemic left ventricle (LV) while 14 (40%) had systemic right ventricle (RV). Compared to the ACEI/ARB group, the ARNI group had greater relative improvement in LV global longitudinal strain (GLS) (28% versus 11% increase from baseline, p < 0.001) and RV-GLS (11% versus 4% increase from baseline, p < 0.001), and greater relative improvement in New York Heart Association functional class (-14 versus -2% change from baseline, p = 0.006) and N-terminal pro-brain natriuretic peptide levels (-29% versus -13% change from baseline, p < 0.001). These results were consistent across different systemic ventricular morphologies.

CONCLUSIONS

ARNI was associated with improvement in biventricular systolic function, functional status, and neurohormonal activation, suggesting prognostic benefit. These results provide a foundation for a randomized clinical trial to empirically test the prognostic benefits of ARNI in adults with CHD, as the next step towards evidence-based recommendations for heart failure management in this population.

End-stage heart failure in congenitally corrected transposition of the great arteries: a multicentre study

BACKGROUND AND AIMS

For patients with congenitally corrected transposition of the great arteries (ccTGA), factors associated with progression to end-stage congestive heart failure (CHF) remain largely unclear.

METHODS

This multicentre, retrospective cohort study included adults with ccTGA seen at a congenital heart disease centre. Clinical data from initial and most recent visits were obtained. The composite primary outcome was mechanical circulatory support, heart transplantation, or death.

RESULTS

From 558 patients (48% female, age at first visit 36 ± 14.2 years, median follow-up 8.7 years), the event rate of the primary outcome was 15.4 per 1000 person-years (11 mechanical circulatory support implantations, 12 transplantations, and 52 deaths). Patients experiencing the primary outcome were older and more likely to have a history of atrial arrhythmia. The primary outcome was highest in those with both moderate/severe right ventricular (RV) dysfunction and tricuspid regurgitation (n = 110, 31 events) and uncommon in those with mild/less RV dysfunction and tricuspid regurgitation (n = 181, 13 events, P < .001). Outcomes were not different based on anatomic complexity and history of tricuspid valve surgery or of subpulmonic obstruction. New CHF admission or ventricular arrhythmia was associated with the primary outcome. Individuals who underwent childhood surgery had more adverse outcomes than age- and sex-matched controls. Multivariable Cox regression analysis identified older age, prior CHF admission, and severe RV dysfunction as independent predictors for the primary outcome.

CONCLUSIONS

Patients with ccTGA have variable deterioration to end-stage heart failure or death over time, commonly between their fifth and sixth decades. Predictors include arrhythmic and CHF events and severe RV dysfunction but not anatomy or need for tricuspid valve surgery.

Chest pain epidemiology and care quality for Aboriginal and Torres Strait Islander peoples in Victoria, Australia: a population-based cohort study from 2015 to 2019

Background

This study examined chest pain epidemiology and care quality for Aboriginal and Torres Strait Islander ('Indigenous') patients presenting to hospital via emergency medical services (EMS) with chest pain.

Methods

State-wide population-based cohort study of consecutive patients attended by ambulance for acute chest pain with individual linkage to emergency, hospital admission and mortality data in the state of Victoria, Australia from January 2015 to June 2019. Multivariable models were used to assess for differences in pre-hospital and hospital adherence to care quality, process measures and clinical outcomes.

Findings

From 204,969 EMS attendances for chest pain, 3890 attendances (1.9%) identified as Aboriginal or Torres Strait Islander. Age-standardized incidence rates were higher overall for Indigenous people (3128 vs. 1147 per 100,000 person-years, incidence rate ratio 2.73, 95% CI 2.72-2.74), this difference being particularly striking for younger patients, women, and those residing in outer regional areas. In multivariable models, adherence to care quality and process measures was lower for attendances involving Indigenous people. In the pre-hospital setting, Indigenous people were less likely to be provided intravenous access or analgesia. In the hospital setting, Indigenous people were less likely to be seen by emergency clinicians within target time and less likely to transferred following myocardial infarction to a revascularization capable centre.

Interpretation

Incidence of acute chest pain presentations is high among Indigenous people in Victoria, Australia. Opportunities to improve the quality of care for Indigenous Australians presenting with acute chest pain are identified.

Funding

National Health and Medical Research Council, National Heart Foundation.

Exercise Capacity, NT-proBNP, and Exercise Hemodynamics in Adults Post-Fontan

BACKGROUND

Cardiopulmonary exercise testing (CPET) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) measurement are frequently performed in adults post-Fontan, but their correlations with exercise invasive hemodynamics are poorly understood. Moreover, whether exercise cardiac catheterization provides incremental prognostic information is unknown.

OBJECTIVES

The authors sought to correlate resting and exercise Fontan pressures (FP) and pulmonary artery wedge pressure (PAWP) with peak oxygen consumption (VO2) on CPET, NT-proBNP, and clinical outcomes.

METHODS

This was a retrospective cohort of 50 adults (age ≥18 years) post-Fontan undergoing supine exercise venous catheterization between 2018 and 2022.

RESULTS

Median age was 31.5 years (IQR: 23.7-36.5 years). Ventricular ejection fraction was 48.5% ± 13.0%. Exercise FP and PAWP were related to peak VO2 and ln NT-proBNP levels. Patients with peak VO2 <50% predicted had higher exercise FP (30.0 ± 6.8 mm Hg vs 19 mm Hg [IQR: 16-24 mm Hg]; P < 0.001) and PAWP (25.9 ± 6.3 mm Hg vs 15.1 ± 7.0 mm Hg; P <0.001) compared with those with more preserved exercise capacity. Exercise FP (30.0 ± 7.1 mm Hg vs 23.2 ± 7.2 mm Hg; P = 0.003) and PAWP (25.1 ± 6.7 mm Hg vs 18.8 ± 7.9 mm Hg; P = 0.006) were higher in those with NT-proBNP levels ≥300 pg/mL. During a follow-up of 0.9 years (IQR: 0.6-2.9 years), exercise FP and PAWP remained independently associated with a composite of death, cardiac transplantation, or hospitalization due to heart failure/refractory arrhythmias after adjusting for confounders.

CONCLUSIONS

In adults post-Fontan, resting and exercise FP and PAWP were inversely related to exercise capacity on noninvasive CPET, and exercise hemodynamics were directly related to NT-proBNP levels. Exercise FP and PAWP were independently associated with clinical outcomes and might be more sensitive than resting values to predict clinical outcomes.

Optimizing Referral Timing of Patients With Fontan Circulatory Failure for Heart Transplant

BACKGROUND

There are no criteria guiding the timing of heart transplant referral for Fontan patients, nor are there any characteristics of those deferred or declined listing reported. This study examines comprehensive transplant evaluations for Fontan patients of all ages, listing decisions, and outcomes to inform referral practices.

METHODS

Retrospective review of 63 Fontan patients formally assessed by the advanced heart failure service and presented at Mayo Clinic transplant selection committee meetings (TSM) January 2006 to April 2021. The study is compliant with the Helsinki Congress and Declaration of Istanbul and included no prisoners. Statistical analysis was performed with Wilcoxon Rank Sum and Fisher's Exact tests.

RESULTS

Median age at TSM was 26 years (17.5, 36.5). Most were approved (38/63 [60%]); 9 of 63 (14%) were deferred and 16 of 63 (25%) were declined. Approved patients more commonly were <18 years old at TSM (15/38 [40%] vs 1/25 [4%], P = .002) compared with those deferred/declined. Complications of Fontan circulatory failure were less common in approved vs deferred/declined patients: ascites (15/38 [40%] vs 17/25 [68%], P = .039), cirrhosis (16/38 [42%] vs 19/25 [76%], P = .01), and renal insufficiency (6/38 [16%] vs 11/25 [44%], P = .02). Ejection fraction and atrioventricular valve regurgitation did not differ between groups. Pulmonary artery wedge pressure was overall high normal (12 mm Hg [9,16]) but higher in deferred/declined vs approved patients, 14.5 (11, 19) vs 10 (8, 13.5) mm Hg, P = .015. Overall survival was significantly lower in deferred/declined patients (P = .0018).

CONCLUSION

Fontan patient referral for heart transplant at younger age and before the onset of end-organ complications is associated with increased approval for transplant listing.

Ethics guidelines use and Indigenous governance and participation in Aboriginal and Torres Strait Islander health research: a national survey

OBJECTIVES

To assess the use of NHMRC Indigenous research guidelines by Australian researchers and the degree of Aboriginal and Torres Strait Islander governance and participation in Indigenous health research.

DESIGN, SETTING, PARTICIPANTS

Cross-sectional survey of people engaged in Indigenous health research in Australia, comprising respondents to an open invitation (social media posts in general and Indigenous health research networks) and authors of primary Indigenous health research publications (2015-2019) directly invited by email.

MAIN OUTCOME MEASURES

Reported use of NHMRC guidelines for Indigenous research; reported Indigenous governance and participation in Indigenous health research.

RESULTS

Of 329 people who commenced the survey, 247 people (75%) provided responses to all questions, including 61 Indigenous researchers (25%) and 195 women (79%). The NHMRC guidelines were used "all the time" by 206 respondents (83%). Most respondents (205 of 247, 83%) reported that their research teams included Indigenous people, 139 reported dedicated Indigenous advisory boards (56%), 91 reported designated seats for Indigenous representatives on ethics committees (37%), and 43 reported Indigenous health research ethics committees (17%); each proportion was larger for respondents working in Indigenous community-controlled organisations than for those working elsewhere. More than half the respondents reported meaningful Indigenous participation during five of six research phases; the exception was data analysis (reported as apparent "none" or "some of the time" by 143 participants, 58%).

CONCLUSIONS

Indigenous health research in Australia is largely informed by non-Indigenous world views, led by non-Indigenous people, and undertaken in non-Indigenous organisations. Re-orientation and investment are needed to give control of the framing, design, and conduct of Indigenous health research to Indigenous people.

Abstract 140: The Incidence Of Stroke In Indigenous Populations Of Countries With A Very High Human Development Index: A Systematic Review

Introduction: Despite known socioeconomic and health disparities affecting Indigenous populations in developed countries, stroke incidence data are sparse. With Indigenous Advisory Board oversight, we undertook a systematic review to compare Indigenous with non-Indigenous stroke incidence rates in countries with a very high Human Development Index (HDI).

Methods: We identified population-based stroke incidence studies published from 1990-2022 in Indigenous adult populations of developed countries using PubMed, EMBASE and Global Health databases, without language restriction. We excluded non-peer-reviewed sources, studies with <10 Indigenous people, or studies not covering a 35-64 year minimum age range. Two reviewers independently screened titles, abstracts, and full texts, and extracted data. We assessed quality using "ideal" criteria for population-based stroke incidence studies, the Newcastle-Ottawa Scale for risk of bias, and CONSIDER criteria for Indigenous research.

Results: Among 13,041 publications, 24 studies (19 full text, 5 abstracts) from 7 countries met inclusion criteria. Compared with respective non-Indigenous populations (Fig 1), age-standardised incidence rates were greater in Aboriginal and Torres Strait Islander Australians (ratios ranging from 1.7-3.2), American Indians (1.2), Sámi of Sweden/Norway (1.08-2.14), and Singaporean Malay (1.7-1.9), with higher rate ratios at younger ages. Studies had substantial heterogeneity in design and risk of bias. Few investigators reported Indigenous stakeholder involvement.

Conclusions: In countries with a very high HDI, available data suggest marked disparities in stroke incidence in Indigenous populations, although there are gaps in data availability and quality. Indigenous stakeholder involvement in studies is infrequently reported. A greater understanding of stroke incidence in these populations is imperative for informing effective societal responses.

Long-Term Outcomes After Atrial Switch Operation for Transposition of the Great Arteries

BACKGROUND

For patients with d-loop transposition of the great arteries (d-TGA) with a systemic right ventricle after an atrial switch operation, there is a need to identify risks for end-stage heart failure outcomes.

OBJECTIVES

The authors aimed to determine factors associated with survival in a large cohort of such individuals.

METHODS

This multicenter, retrospective cohort study included adults with d-TGA and prior atrial switch surgery seen at a congenital heart center. Clinical data from initial and most recent visits were obtained. The composite primary outcome was death, transplantation, or mechanical circulatory support (MCS).

RESULTS

From 1,168 patients (38% female, age at first visit 29 ± 7.2 years) during a median 9.2 years of follow-up, 91 (8.8% per 10 person-years) met the outcome (66 deaths, 19 transplantations, 6 MCS). Patients experiencing sudden/arrhythmic death were younger than those dying of other causes (32.6 ± 6.4 years vs 42.4 ± 6.8 years; P < 0.001). There was a long duration between sentinel clinical events and end-stage heart failure. Age, atrial arrhythmia, pacemaker, biventricular enlargement, systolic dysfunction, and tricuspid regurgitation were all associated with the primary outcome. Independent 5-year predictors of primary outcome were prior ventricular arrhythmia, heart failure admission, complex anatomy, QRS duration >120 ms, and severe right ventricle dysfunction based on echocardiography.

CONCLUSIONS

For most adults with d-TGA after atrial switch, progress to end-stage heart failure or death is slow. A simplified prediction score for 5-year adverse outcome is derived to help identify those at greatest risk.

Heart Failure in Adult Congenital Heart Disease

As the population of adult congenital heart disease patients ages and grows, so too does the burden of heart failure in this population. Despite the advances in medical and surgical therapies over the last decades, heart failure in adult congenital heart disease remains a formidable complication with high morbidity and mortality. This review focuses on the challenges in determining the true burden and management of heart failure in adult congenital heart disease. There is a particular focus on the need for developing a common language for classifying and reporting heart failure in adult congenital heart disease, the clinical presentation and prognostication of heart failure in adult congenital heart disease, the application of hemodynamic evaluation, and advanced heart failure treatment. A common case study of heart failure in adult congenital heart disease is utilized to illustrate these key concepts.

Coronary heart disease and stroke in the Sami and non-Sami populations in rural Northern and Mid Norway-the SAMINOR Study

BACKGROUND

Previous studies have suggested that Sami have a similar risk of myocardial infarction and a higher risk of stroke compared with non-Sami living in the same geographical area.

DESIGN

Participants in the SAMINOR 1 Survey (2003-2004) aged 30 and 36-79 years were followed to the 31 December 2016 for observation of fatal or non-fatal events of acute myocardial infarction (AMI), coronary heart disease (CHD), ischaemic stroke (IS), stroke and a composite endpoint (fatal or non-fatal AMI or stroke).

AIM

Compare the risk of AMI, CHD, IS, stroke and the composite endpoint in Sami and non-Sami populations, and identify intermediate factors if ethnic differences in risks are observed.

METHODS

Cox regression models.

RESULTS

The sex-adjusted and age-adjusted risks of AMI (HR for Sami versus non-Sami 0.99, 95% CI: 0.83 to 1.17), CHD (HR 1.03, 95% CI: 0.93 to 1.15) and of the composite endpoint (HR 1.09, 95% CI: 0.95 to 1.24) were similar in Sami and non-Sami populations. Sami ethnicity was, however, associated with increased risk of IS (HR 1.36, 95% CI: 1.10 to 1.68) and stroke (HR 1.31, 95% CI: 1.08 to 1.58). Height explained more of the excess risk observed in Sami than conventional risk factors.

CONCLUSIONS

The risk of IS and stroke were higher in Sami and height was identified as an important intermediate factor as it explained a considerable proportion of the ethnic differences in IS and stroke. The risk of AMI, CHD and the composite endpoint was similar in Sami and non-Sami populations.

Pregnancy in women with pre-existent ischaemic heart disease: a systematic review with individualised patient data

INTRODUCTION

Studies on pregnancy risk in women with ischaemic heart disease (IHD) have mainly excluded pregnancies in women with pre-existent IHD. There is a need for better information about the pregnancy risks in these women and their offspring.

METHODS

We performed a systematic review searching the PubMed/MEDLINE public database for pregnancy in women with pre-existent IHD analysing the cardiac, obstetric and fetal/neonatal outcome of pregnancy in women with pre-existing IHD. Individual patient data were requested from large series. The primary outcome endpoints was a composite of ischaemic complications including maternal death, acute coronary syndrome and ventricular tachycardia.

RESULTS

116 women with pre-existent IHD had 124 pregnancies including one twin pregnancy. They had a 21% chance of having an uncomplicated pregnancy (completed pregnancy without cardiovascular, obstetric or fetal/neonatal complications, n=26). Primary (ischaemic) endpoints occurred in 9% (n=11). Women with atherosclerosis had more cardiovascular complications compared with pregnancies in women with other underlying pathology for IHD (50%vs23%, P=0.02) but no significant difference in occurrence of primary endpoints (13% vs 9%, P=0.53). There were two maternal cardiac deaths (2%), one of which occurred in the 18th week of pregnancy and the other postpartum. Obstetric complications occurred in 58% (n=65) of pregnancies and fetal/neonatal complications in 42% (n=47).

CONCLUSION

Pregnancies in women with pre-existing IHD are high-risk pregnancies. These women have a high risk of ischaemic cardiovascular complications including 2% maternal mortality. The risk of ischaemic complications is especially high among women with atherosclerotic coronary artery disease.

Hospitalization Trends and Health Resource Use for Adult Congenital Heart Disease-Related Heart Failure

Background This study assessed trends in heart failure ( HF) hospitalizations and health resource use in patients with adult congenital heart disease ( ACHD ). Methods and Results The Nationwide Inpatient Sample was used to compare ACHD with non- ACHD HF hospitalization and health resource trends. Health resource use was assessed using total hospital charges, hospital length of stay, and procedural burden. A total of 87 175±2676 ACHD -related HF hospitalizations occurred between 1998 and 2011. During this time, ACHD HF hospitalizations increased 91% (4620±438-8809±740, P<0.0001) versus a 21% increase in non- ACHD HF hospitalizations ( P=0.003). ACHD HF hospitalization was associated with longer length of stay ( ACHD HF versus non- ACHD HF, 7.2±0.09 versus 6.8±0.02 days; P<0.0001), greater procedural burden, and higher charges ($81 332±$1650 versus $52 050±$379; P<0.0001). ACHD HF hospitalization charges increased 258% during the study period ($26 533±$1816 in 1998 versus $94 887±$8310 in 2011; P=0.0002), more than double that for non- ACHD HF ( P=0.04). Patients with ACHD HF hospitalized in high-volume ACHD centers versus others were more likely to undergo invasive hemodynamic testing (30.2±0.6% versus 20.7±0.5%; P<0.0001) and to receive cardiac resynchronization/defibrillator devices (4.7±0.3% versus 1.8±0.2%; P<0.0001) and mechanical circulatory support (3.9±0.2% versus 2.4±0.2%; P<0.0001). Conclusions ACHD -related HF hospitalizations have increased dramatically in recent years and are associated with disproportionately higher costs, procedural burden, and health resource use.

Limited Accuracy of Administrative Data for the Identification and Classification of Adult Congenital Heart Disease

BACKGROUND

Administrative data sets utilize billing codes for research and quality assessment. Previous data suggest that such codes can accurately identify adults with congenital heart disease (CHD) in the cardiology clinic, but their use has yet to be validated in a larger population.

METHODS AND RESULTS

All administrative codes from an entire health system were queried for a single year. Adults with a CHD diagnosis code (International Classification of Diseases, Ninth Revision, (ICD-9) codes 745-747) defined the cohort. A previously validated hierarchical algorithm was used to identify diagnoses and classify patients. All charts were reviewed to determine a gold standard diagnosis, and comparisons were made to determine accuracy. Of 2399 individuals identified, 206 had no CHD by the algorithm or were deemed to have an uncertain diagnosis after provider review. Of the remaining 2193, only 1069 had a confirmed CHD diagnosis, yielding overall accuracy of 48.7% (95% confidence interval, 47-51%). When limited to those with moderate or complex disease (n=484), accuracy was 77% (95% confidence interval, 74-81%). Among those with CHD, misclassification occurred in 23%. The discriminative ability of the hierarchical algorithm (C statistic: 0.79; 95% confidence interval, 0.77-0.80) improved further with the addition of age, encounter type, and provider (C statistic: 0.89; 95% confidence interval, 0.88-0.90).

CONCLUSIONS

ICD codes from an entire healthcare system were frequently erroneous in detecting and classifying CHD patients. Accuracy was higher for those with moderate or complex disease or when coupled with other data. These findings should be taken into account in future studies utilizing administrative data sets in CHD.

Ascending aortic size in aortic coarctation depends on aortic valve morphology: Understanding the bicuspid valve phenotype

BACKGROUND

In roughly half of patients with coarctation of the aorta (CoA), the aorta may be enlarged. It is uncertain whether enlargement is independent of aortic valve morphology. We sought to compare aortic size in CoA with a tricuspid valve (TAV) to those with bicuspid aortic valve (BAV).

METHODS

Sixty-eight CoA patients and 20 healthy controls with prior cardiac magnetic resonance (CMR) imaging were included. CMR was retrospectively reanalyzed to measure aortic root and mid-ascending aorta. The maximum aortic diameter was compared between CoA with TAV, CoA with BAV, and control groups.

RESULTS

CoA with TAV patients (n=27) had smaller aortic root diameters than CoA with BAV (n=41) (32±4.9 vs. 37±5.8mm, p=0.001), despite being older (40 vs. 32years, p=0.01). Similarly, TAV CoA patients had a smaller mid-ascending aortic diameter (28±4.5 vs. 33±6.9mm, p=0.019) than BAV patients. TAV CoA was similar to controls in all metrics. Twenty-four patients (35%) with CoA had dilated aortas (>37mm), of which 79% had BAV. A history of hypertension did not predict larger aortic root or mid-ascending aortic dimensions.

CONCLUSIONS

In patients with CoA, TAV is associated with smaller aortic size compared to those with BAV, and similar to healthy controls. Aortic size in CoA is independent of hypertension. Therefore, aortopathy associated with BAV is likely a reflection of the BAV phenotype rather than CoA or its physiologic effects. This distinction may have implications for the frequency and types of monitoring and treatment of CoA patients.

Triheptanoin versus trioctanoin for long-chain fatty acid oxidation disorders: a double blinded, randomized controlled trial

BACKGROUND

Observational reports suggest that supplementation that increases citric acid cycle intermediates via anaplerosis may have therapeutic advantages over traditional medium-chain triglyceride (MCT) treatment of long-chain fatty acid oxidation disorders (LC-FAODs) but controlled trials have not been reported. The goal of our study was to compare the effects of triheptanoin (C7), an anaplerotic seven-carbon fatty acid triglyceride, to trioctanoin (C8), an eight-carbon fatty acid triglyceride, in patients with LC-FAODs.

METHODS

A double blinded, randomized controlled trial of 32 subjects with LC-FAODs (carnitine palmitoyltransferase-2, very long-chain acylCoA dehydrogenase, trifunctional protein or long-chain 3-hydroxy acylCoA dehydrogenase deficiencies) who were randomly assigned a diet containing 20% of their total daily energy from either C7 or C8 for 4 months was conducted. Primary outcomes included changes in total energy expenditure (TEE), cardiac function by echocardiogram, exercise tolerance, and phosphocreatine recovery following acute exercise. Secondary outcomes included body composition, blood biomarkers, and adverse events, including incidence of rhabdomyolysis.

RESULTS

Patients in the C7 group increased left ventricular (LV) ejection fraction by 7.4% (p = 0.046) while experiencing a 20% (p = 0.041) decrease in LV wall mass on their resting echocardiogram. They also required a lower heart rate for the same amount of work during a moderate-intensity exercise stress test when compared to patients taking C8. There was no difference in TEE, phosphocreatine recovery, body composition, incidence of rhabdomyolysis, or any secondary outcome measures between the groups.

CONCLUSIONS

C7 improved LV ejection fraction and reduced LV mass at rest, as well as lowering heart rate during exercise among patients with LC-FAODs.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov NCT01379625.

Noninvasive Imaging in Adult Congenital Heart Disease

Multimodality cardiovascular imaging plays a central role in caring for patients with congenital heart disease (CHD). CHD clinicians and scientists are interested not only in cardiac morphology but also in the maladaptive ventricular responses and extracellular changes predisposing to adverse outcomes in this population. Expertise in the applications, strengths, and pitfalls of these cardiovascular imaging techniques as they relate to CHD is essential. The purpose of this article is to provide an overview of cardiovascular imaging in CHD. We focus on the role of 3 widely used noninvasive imaging techniques in CHD—echocardiography, cardiac magnetic resonance imaging, and cardiac computed tomography. Consideration is given to the common goals of cardiac imaging in CHD, including assessment of structural and residual heart disease before and after surgery, quantification of ventricular volume and function, stress imaging, shunt quantification, and tissue characterization. Extracardiac imaging is highlighted as an increasingly important aspect of CHD care.

Transesophageal Echocardiography in Atrial Fibrillation

Transesophageal echocardiography (TEE) plays an important role in atrial fibrillation (AF), mainly to detect the presence of left atrial appendage (LAA) thrombus. It is useful in direct current cardioversion (DCC) guidance and for AF ablation and LAA occlusion. With the increasing number of patients affected by AF, the use of TEE will grow and become an important screening modality for LAA thrombus. Future direction includes broader multi-institutional use; further tools to risk stratify patients; and the use of a new spectrum of oral anticoagulants and their cost-effectiveness in patients with AF undergoing DCC, AF ablation, and LAA occlusion.

Heart Failure in Adult Congenital Heart Disease: Nonpharmacologic Treatment Strategies

In early stages, heart failure (HF) in adult congenital heart disease (ACHD) remains an elusive diagnosis. Many ACHD patients seem well-compensated owing to chronic physical and psychological adaptations. HF biomarkers and cardiopulmonary exercise tests are often markedly abnormal, although patients report stable health and good quality of life. Treatment differs from acquired HF. Evidence for effective drug therapy in ACHD-related HF is lacking. Residual ventricular, valvular, and vascular abnormalities contribute to HF pathophysiology, leading to an emphasis on nonpharmacologic treatment strategies. This article reviews emerging perspectives on nonpharmacologic treatment strategies, including catheter-based interventions, surgical correction, and palliative care.

Myocardial factor revisited: The importance of myocardial fibrosis in adults with congenital heart disease

Pioneers in congenital heart surgery observed that exercise capacity did not return to normal levels despite successful surgical repair, leading some to cite a "myocardial factor" playing a role. They conjectured that residual alterations in myocardial function would be significant for patients' long-term outlook. In fulfillment of their early observations, today's adult congenital heart disease (ACHD) population shows well-recognized features of heart failure, even among patients without clear residual anatomic or hemodynamic abnormalities, demonstrating the vital role of the myocardium in their morbidity and mortality. Whereas the 'myocardial factor' was an elusive concept in the early history of congenital heart care, we now have imaging techniques to detect and quantify one such factor--myocardial fibrosis. Understanding the importance of myocardial fibrosis as a final common pathway in a variety of congenital lesions provides a framework for both the study and treatment of clinical heart failure in this context. While typical heart failure pharmacology should reduce or attenuate fibrogenesis, efforts to show meaningful improvements with standard pharmacotherapy in ACHD repeatedly fall short. This paper considers the importance of myocardial fibrosis and function, the current body of evidence for myocardial fibrosis in ACHD, and its implications for research and treatment.