Systolic dysfunction of the subpulmonary left ventricle is associated with the severity of heart failure in patients with a systemic right ventricle

External Validation of a Risk Score Model for Predicting Major Clinical Events in Adults After Atrial Switch

BACKGROUND

A risk model has been proposed to provide a patient individualized estimation of risk for major clinical events (heart failure events, ventricular arrhythmia, all-cause mortality) in patients with transposition of the great arteries and atrial switch surgery. We aimed to externally validate the model.

METHODS AND RESULTS

A retrospective, multicentric, longitudinal cohort of 417 patients with transposition of the great arteries (median age, 24 years at baseline [interquartile range, 18-30]; 63% men) independent of the model development and internal validation cohort was studied. The performance of the prediction model in predicting risk at 5 years was assessed, and additional predictors of major clinical events were evaluated separately in our cohort. Twenty-five patients (5.9%) met the major clinical events end point within 5 years. Model validation showed good discrimination between high and low 5-year risk patients (Harrell C index of 0.73 [95% CI, 0.65-0.81]) but tended to overestimate this risk (calibration slope of 0.20 [95% CI, 0.03-0.36]). In our population, the strongest independent predictors of major clinical events were a history of heart failure and at least mild impairment of the subpulmonary left ventricle function.

CONCLUSIONS

We reported the first external validation of a major clinical events risk model in a large cohort of adults with transposition of the great arteries. The model allows for distinguishing patients at low risk from those at intermediate to high risk. Previous episode of heart failure and subpulmonary left ventricle dysfunction appear to be key markers in the prognosis of patients. Further optimizing risk models are needed to individualize risk predictions in patients with transposition of the great arteries.

Biventricular performance in adults with a systemic right ventricle: new insights from myocardial work analysis

To evaluate biventricular mechanics by means of echo-derived myocardial work (MW) analysis in patients with a systemic right ventricle (sRV). Comprehensive echo data were collected in all patients with a sRV who underwent transthoracic echocardiography at our tertiary centre between 2020 and 2021 including sRV function indices, global longitudinal strain (GLS) of right and left ventricle (RV/LV), biventricular MW, and atrial strain in those with congenitally corrected transposition of the great arteries (ccTGA). Fifty-six patients (37 [30.97-45.87]years, 59% male) and 49 healthy individuals matched per age and sex were included for comparison. Global work index (GWI:1106 [869.80-1293.10] Vs 314.2 [281.5-358.2]mmHg%, p < 0.0001) and global constructive work(GCW: 1542.50 [1338.9-1718.50] Vs 416.4 [365.70-464]mmHg%, p < 0.0001) were both increased for sRV compared to normal RV, reflecting exposition to a systemic afterload, with a contemporary raise in wasted work (GWW:197 [138.50-322.20] Vs 26.09 [17.80-43.48]mmHg%, p < 0.0001) and impaired efficiency (GWE:89 [83-93.54] Vs 93.67 [91.67-96] %, p < 0.0001). Conversely, sRV showed reduced MW indices in comparison to normal LV(p < 0.0001 for all). Non-systemic LV demonstrated normal GLS values (19.51 ± 3.9%), but reduced GWI (479 [368-665] Vs 2172 [1978-2386]mmHg%, p < 0.0001) and GCW (708 [490-815]mmHg% Vs 86.5 [59.25-118], p < 0.0001). Nevertherless, non-systemic LV showed also impaired efficiency (91 [88-94] Vs 95 [94-97]%, p < 0.0001). LVGLS values were related to RVGLS (R = 0.5, p = 0.00019), suggesting a consistent interventricular dependency. Atrial strain could be assessed in 16 out of 20 (80%) patients with ccTGA: both atria had reduced strain values compared to their normal counterparts. Moreover, pulmonary atrial strain during the reservoir phase was related to LVGWE (R = 0.58, p = 0.047) and inversely related to LVGLS (R = - 0.71, p = 0.0043). MW analysis is feasible in sRV and may provide additional clinical data. In our cohort MW revealed biventricular impairment, in particular for non-systemic LV, in spite of normal GLS values.

Myocardial work of the systemic right ventricle and its association with outcomes

We aimed to evaluate clinical and prognostic significance of myocardial work parameters of the systemic right ventricle (SRV). Thirty-eight patients with the SRV underwent echocardiographic assessment of the SRV systolic function including 3D-echocardiography derived ejection fraction, 2D longitudinal strain and myocardial work analysis. The study endpoint was the combination of all-cause mortality and heart transplantation. Global constructive work (GCW) and global work index (GWI) demonstrated moderate correlation with the 3DE-derived SRV ejection fraction (EF) (Rho 0.64, p < 0.0001 and Rho 0.63, p < 0.0001, respectively). GCW showed the strongest correlation with the BNP level (Rho - 0.77, p < 0.0001), closely followed by GWI, 4-chamber longitudinal strain and 3DE EF (all Rho - 0.73, p < 0.0001). GCW and GWI were significantly lower in patients with moderate or severe tricuspid regurgitation compared with less than moderate regurgitation (1226 ± 439 vs 1509 ± 264 mmHg%, p = 0.02, and 984 ± 348 vs 1259 ± 278 mmHg%, p = 0.01, respectively). During a follow-up of 3.5 (2.8-3.9) years, seven patients (18%) died and one received transplantation (3%). They had significantly lower GCW and GWI compared with patients who did not reach the study endpoint (908 ± 255 vs 1433 ± %, p < 0.001 and 721 ± 210 vs 1173 ± 315 mmHg%, p < 0.001, respectively). In Cox regression analysis, GCW, GWI, 3DE SRV volumes and EF were the best-fit models based on the Akaike Information Criterion, outperforming longitudinal strain parameters. GWI and GCW, novel echocardiographic parameters of myocardial work, provided reliable quantification of the SRV systolic function. GWI, GCW and 3DE-derived SRV parameters were closely associated with all-cause mortality and heart transplantation in patients with the SRV.

Surgical Considerations for the Mitral Valve in Congenitally Corrected Transposition

BACKGROUND

Systemic atrioventricular valve (morphologic tricuspid valve [TV]) regurgitation has been implicated in the development of systemic ventricular failure in congenitally corrected transposition of the great arteries (ccTGA), leading to timely referral for valve replacement. However, the surgical management of subpulmonary atrioventricular valve (morphologic mitral valve [MV]) regurgitation and outcomes has not been well studied.

METHODS

Of 108 ccTGA patients undergoing atrioventricular valve surgery from 1979 to 2022, 22 patients (20%) underwent MV surgery. Demographics, etiology of valve regurgitation, operative details, and outcomes of these 22 patients were retrospectively reviewed. Follow-up at 1, 5, and 10 years was available for 18 (82%), 13 (59%), and 11 patients (50%), respectively.

RESULTS

Median age was 37 years (interquartile range, 29-57 years). Intrinsic MV pathology was present in 18 individuals (82%). Operations included repair in 16 patients (73%), replacement in 6 (27%), and concomitant replacement of TV in 16 (73%). There was 1 perioperative death (5%) in a patient undergoing an emergent operation for severe acute-on-chronic heart failure due to worsening TV regurgitation. During a median follow-up of 12 years (interquartile range, 2-19 years), 7 patients (32%) died. Among the 16 patients who underwent repair, recurrent moderate or greater regurgitation was seen in 15%, 29%, and 43% of repairs in patients with annular, leaflet, and lead-induced regurgitation, respectively.

CONCLUSIONS

Concomitant TV and MV disease occur much less frequently than isolated TV disease in ccTGA. Intrinsic MV disease is most commonly observed but appears less amenable to successful repair compared with mitral repair in the systemic position and suggests MV replacement may be preferred in ccTGA patients.

Prognostic significance of subpulmonary left ventricular size and function in patients with a systemic right ventricle

AIMS

To assess the additional prognostic significance of echocardiographic parameters of subpulmonary left ventricular (LV) size and function in patients with a systemic right ventricle (SRV).

METHODS AND RESULTS

All adults with an SRV who underwent transthoracic echocardiography in 2010-18 at a large tertiary centre were identified. Biventricular size and function were assessed at the most recent examination. The study endpoint was all-cause mortality or heart/heart-lung transplantation. We included 180 patients, with 100 (55.6%) males, with a mean age of 42.4 ± 12.3 years, of whom 103 (57.2%) had undergone Mustard/Senning operations and 77 (42.8%) had congenitally corrected transposition of great arteries. Over 4.9 (3.8-5.7) years, 28 (15.6%) patients died and 4 (2.2%) underwent heart or heart-lung transplantation. Univariable predictors of the study endpoint included age, New York Heart Association functional Class III or IV, history of atrial arrhythmias, presence of a pacemaker or cardioverter defibrillator, high B-type natriuretic peptide, and echocardiographic markers of SRV and subpulmonary LV size and function. On multivariable Cox analysis of echocardiographic variables, indexed LV end-systolic diameter [ESDi; hazard ratio (HR) 2.77 (95% confidence interval, CI) 1.35-5.68, P = 0.01], LV fractional area change [FAC; HR 0.7 (95% CI 0.57-0.85), P = 0.002), SRV basal diameter [HR 1.66 (95% CI 1.21-2.29), P = 0.005], and SRV FAC [HR 0.65 (95% CI 0.49-0.87), P = 0.008] remained predictive of mortality or transplantation. On receiver-operating characteristic analysis, subpulmonary LV parameters performed better than SRV markers in predicting adverse events.

CONCLUSION

SRV basal diameter, SRV FAC, LV ESDi, and LV FAC are significantly and independently associated with mortality and transplantation in adults with an SRV. Accurate echocardiographic assessment of both SRV and subpulmonary LV is, therefore, essential to inform risk stratification and management.

Indications for Cardiac Resynchronization Therapy in Patients with Congenital Heart Disease

Heart failure in patients with congenital heart disease (CHD) stems from unique causes compared with the elderly. Patients with CHD face structural abnormalities and malformations present from birth, leading to altered cardiac function and potential complications. In contrast, elderly individuals primarily experience heart failure due to age-related changes and underlying cardiovascular conditions. Cardiac resynchronization therapy (CRT) can benefit patients with CHD, although it presents numerous challenges. The complexities of CHD anatomy and limited access to appropriate venous sites for lead placement make CRT implantation demanding.

Echo-Doppler and strain assessment of filling pressures in adults with congenitally corrected transposition and systemic right ventricles

AIMS

Systolic dysfunction of the systemic right ventricle (sRV) is common in adults with transposition of the great arteries and sRV. In acquired disease, diastology analysis for assessment of filling pressures (FP) is paramount in patient care.

METHODS AND RESULTS

Retrospective analysis of 47 adults with sRV without prior systemic tricuspid valve surgery undergoing catheterization and echocardiography within 7 days (median -2 [-1, -3]) from January 2000 to February 2021 at our institution. Median age was 48 (31, 55) years, and 16 (34.0%) patients were female. FPs were normal in 21 patients (44.7%). Left atrial size was enlarged in most patients (83.0%) with mean indexed value 58.3 ± 23.4 mL/m2. Tissue Doppler e' was not significantly different between those with high FPs vs. normal (medial 0.07 ± 0.03 vs. 0.08 ± 0.03 m/s, P = 0.63; lateral 0.08 ± 0.04 vs. 0.08 ± 0.04 m/s, P = 0.88). E velocity and subpulmonic mitral regurgitant velocity were higher in those with high FPs (0.9 ± 0.3 vs. 0.6 ± 0.2 m/s, P = 0.005; 3.8 ± 1.1 vs. 2.8 ± 0.9 m/s, P = 0.004). Left atrial reservoir strain, sRV global longitudinal strain, and subpulmonic left ventricular strain were worse in those with high FP (18.0 ± 7.6 vs. 27.9 ± 10.2%, P = 0.0009; -13.0 ± 4.4 vs. -17.9 ± 5.0%, P = 0.002; -16.8 ± 5.7 vs. -23.0 ± 3.8%, P = 0.001).

CONCLUSION

Despite the complex anatomy, FPs can be assessed non-invasively in adults with sRV without prior systemic tricuspid valve surgery. The current guideline algorithm for diastolic dysfunction in acquired heart disease has limited applicability in this population. Given the limitations of Doppler in this heterogeneous population, strain analysis can be a helpful adjunct for estimation of FPs.

Heart failure in systemic right ventricle: Mechanisms and therapeutic options

d-loop transposition of the great arteries (d-TGA) and congenitally corrected transposition of the great arteries (cc-TGA) feature a right ventricle attempting to sustain the systemic circulation. A systemic right ventricle (sRV) cannot support cardiac output in the long run, eventually decompensating and causing heart failure. The burden of d-TGA patients with previous atrial switch repair and cc-TGA patients with heart failure will only increase in the coming years due to the aging adult congenital heart disease population and improvements in the management of advanced heart failure. Clinical data still lags behind in developing evidence-based guidelines for risk stratification and management of sRV patients, and clinical trials for heart failure in these patients are underrepresented. Recent studies have provided foundational data for the commencement of robust clinical trials in d-TGA and cc-TGA patients. Further insights into the multifactorial nature of sRV failure can only be provided by the results of such studies. This review discusses the mechanisms of heart failure in sRV patients with biventricular circulation and how these mediators may be targeted clinically to alleviate sRV failure.

Left bundle branch area pacing in congenital heart disease

AIMS

Left bundle branch area pacing (LBBAP) has been shown to be effective and safe. Limited data are available on LBBAP in the congenital heart disease (CHD) population. This study aims to describe the feasibility and safety of LBBAP in CHD patients compared with non-CHD patients.

METHODS AND RESULTS

This is a single-centre, non-randomized observational study recruiting consecutive patients with bradycardia indication. Demographic data, ECGs, imaging, and procedural data including lead parameters were recorded. A total of 39 patients were included: CHD group (n = 13) and non-CHD group (n = 26). Congenital heart disease patients were younger (55 ± 14.5 years vs. 73.2 ± 13.1, P < 0.001). Acute success was achieved in all CHD patients and 96% (25/26) of non-CHD patients. No complications were encountered in either group. The procedural time for CHD patients was comparable (96.4 ± 54 vs. 82.1 ± 37.9 min, P = 0.356). Sheath reshaping was required in 7 of 13 CHD patients but only in 1 of 26 non-CHD patients, reflecting the complex and distorted anatomy of the patients in this group. Lead parameters were similar in both groups; R wave (11 ± 7 mV vs. 11.5 ± 7.5, P = 0.881) and pacing threshold (0.6 ± 0.3 V vs. 0.7 ± 0.3, P = 0.392). Baseline QRS duration was longer in the CHD group (150 ± 28.2 vs. 118.6 ± 26.6 ms, P = 0.002). Despite a numerically greater reduction in QRS and a similar left ventricular activation time (65.9 ± 6.2 vs. 67 ± 16.8 ms, P = 0.840), the QRS remained longer in the CHD group (135.5 ± 22.4 vs. 106.9 ± 24.7 ms, P = 0.005).

CONCLUSION

Left bundle branch area pacing is feasible and safe in CHD patients as compared to that in non-CHD patients. Procedural and fluoroscopy times did not differ between both groups. Lead parameters were satisfactory and stable over a short-term follow-up.

A new score for life-threatening ventricular arrhythmias and sudden cardiac death in adults with transposition of the great arteries and a systemic right ventricle

AIMS

To investigate the incidence of major adverse ventricular arrhythmias and related events (MAREs) and to develop a stratification tool predicting MAREs in adults with a systemic right ventricle (sRV).

METHODS AND RESULTS

In a multicentre approach, all adults (≥16 years old) with a sRV undergoing follow-up between 2000 and 2018 were identified. The incidence of MAREs, defined as sudden cardiac death, sustained ventricular tachycardia, and appropriate implantable cardioverter-defibrillator (ICD) therapy, was analysed. The association of MAREs with clinical, electrical, and echocardiographic parameters was evaluated. A total of 1184 patients (median age 27.1 years; interquartile range 19.9-34.9 years; 59% male; 70% with atrial switch repair for D-transposition of the great arteries) were included. The incidence of MAREs was 6.3 per 1000 patient-years. On multivariate analysis, age, history of heart failure, syncope, QRS duration, severe sRV dysfunction and at least moderate left ventricular outflow tract obstruction were retained in the final model with a C-index of 0.78 [95% confidence interval (CI) 0.72-0.83] and a calibration slope of 0.93 (95% CI 0.64-1.21). For every five ICDs implanted in patients with a 5-year MARE risk >10%, one patient may potentially be spared from a MARE.

CONCLUSION

Sudden cardiac death remains a devastating cause of death in a contemporary adult cohort with a sRV. A prediction model based on clinical, electrocardiographic, and echocardiographic parameters was devised to estimate MARE risk and to identify high-risk patients who may benefit from primary prevention ICD implantation.

Myocardial fibrosis in congenital heart disease

Myocardial fibrosis resulting from the excessive deposition of collagen fibers through the myocardium is a common histopathologic finding in a wide range of cardiovascular diseases, including congenital anomalies. Interstitial fibrosis has been identified as a major cause of myocardial dysfunction since it distorts the normal architecture of the myocardium and impairs the biological function and properties of the interstitium. This review summarizes current knowledge on the mechanisms and detrimental consequences of myocardial fibrosis in heart failure and arrhythmias, discusses the usefulness of available imaging techniques and circulating biomarkers to assess this entity and reviews the current body of evidence regarding myocardial fibrosis in the different subsets of congenital heart diseases with implications in research and treatment.

Malnutrition Increases the Risk of Left Ventricular Remodeling

OBJECTIVES

Malnutrition is associated with increased incidence of heart failure (HF). Left ventricular (LV) remodeling is one of the most important processes in the occurrence and evolution of HF. However, the association between nutritional status and LV remodeling is not well known. The study aimed to investigate the association between malnutrition and LV remodeling.

DESIGN

The study was a retrospective observation study.

SETTING AND PARTICIPANTS

We included patients from the registry of Cardiorenal Improvement study from January 2007 to December 2018 at Guangdong Provincial People's Hospital.

MEASUREMENTS

The primary endpoint was LV remodeling, defined as an absolute decrease in LV ejection fraction ≥10% after discharge compared with baseline. Nutritional status was assessed by the Controlling Nutritional Status (CONUT) score. Eligible patients were divided into absent-mild malnutrition group (CONUT score ≤4) and moderate-severe malnutrition group (CONUT score >4). Univariable and multivariable logistic regression was performed to verify the association between malnutrition and left ventricular remodeling.

RESULTS

A total of 7,217 patients (mean age 61.3±10.5 years, 71.7% male) were included in the final analysis, among which 712 (9.9%) had LV remodeling. The incidence of LV remodeling in moderate-severe malnutrition group was significantly higher than that in absent-mild malnutrition group (12.9% vs. 9.5%, p=0.002). In multivariable logistic regression, moderate-severe malnutrition group was significantly associated with 1.69-fold increased risk of LV remodeling after adjusting confounders (OR: 1.69, CI: 1.32-2.16). Similar results were observed in subgroup stratified by age, gender, and coronary artery disease.

CONCLUSION

Nearly one eighth of patients were classified as moderate-severe malnutrition, 12% of whom had LV remodeling. Moderate-severe malnutrition was associated with 69% increased risk of LV remodeling. Further studies are needed to prospectively evaluate the nutrition-oriented managements on outcomes in LV remodeling.

Contraction patterns of the systemic right ventricle: a three-dimensional echocardiography study

AIMS

To investigate contraction patterns of the systemic right ventricle (SRV) in patients with transposition of great arteries (TGA) post-atrial switch operation and with congenitally corrected transposition of great arteries (ccTGA).

METHODS AND RESULTS

Right ventricular (RV) volumes and ejection fraction (EF) were measured by three-dimensional echocardiography in 38 patients with the SRV (24 TGA and 14 ccTGA; mean age 45 ± 12 years, 63% male), and in 38 healthy volunteers. The RV contraction was decomposed along the longitudinal, radial, and anteroposterior directions providing longitudinal, radial, and anteroposterior EF (LEF, REF, and AEF, respectively) and their contributions to total right ventricular ejection fraction (LEFi, REFi, and AEFi, respectvely). SRV was significantly larger with lower systolic function compared with healthy controls. SRV EF and four-chamber longitudinal strain strongly correlated with B-type natriuretic peptide (BNP) level (Rho -0.73, P < 0.0001 and 0.70, P < 0.0001, respectively). In patients with TGA, anteroposterior component was significantly higher than longitudinal and radial components (AEF 17 ± 4.5% vs. REF 13 ± 4.9% vs. LEF 10 ± 3.3%, P < 0.0001; AEFi 0.48 ± 0.09 vs. REFi 0.38 ± 0.1 vs. LEFi 0.29 ± 0.08, P < 0.0001). In patients with ccTGA, there was no significant difference between three SRV components. AEFi was significantly higher in TGA subgroup compared with ccTGA (0.48 ± 0.09 vs. 0.36 ± 0.08, P = 0.0002).

CONCLUSION

Contraction patterns of the SRV are different in TGA and ccTGA. Anteroposterior component is dominant in TGA providing compensation for impaired longitudinal and radial components, while in ccTGA all components contribute equally to the total EF. SRV EF and longitudinal strain demonstrate strong correlation with BNP level and should be a part of routine echocardiographic assessment of the SRV.

Congenitally Corrected Transposition of the Great Arteries in Adults-A Contemporary Single Center Experience

BACKGROUND

Congenitally corrected transposition of the great arteries (ccTGA) is a rare congenital heart defect (CHD). Contemporary data regarding its outcome in adults are scarce.

METHODS

Retrospective, single-center study of all ccTGA patients over the age of 16 years treated at our center during the time period 2006-2018. Only patients with a biventricular circulation were included. The primary endpoint was all-cause mortality.

RESULTS

Altogether, 96 patients (mean age 32.8 ± 16.0 years, female 50%) with ccTGA and a systemic right ventricle (SRV) were included in the study. An additional CHD was present in 81 patients (84.4%); most common were a ventricular septal defect (VSD) and a left ventricular outflow tract obstruction. Out of the whole cohort, 45 (46.9%) had already undergone cardiac surgery at baseline. During a median follow-up of 6.5 (IQR 2.8-12.7) years, the primary endpoint occurred in 10 patients (10.8%). Cause of death was cardiac in nine patients and suicide in one. Hospitalizations due to heart failure occurred in 48 patients (51.6%). Upon univariate Cox analysis, an NYHA class ≥III, severe tricuspid regurgitation, severe SRV systolic impairment, as well as a reduced left ventricular systolic function were predictors of the primary endpoint. Upon multivariable analysis, only NYHA class ≥ III (HR: 18.66, CI 95%: 3.01-115.80, p = 0.0017) and a reduced left ventricular systolic function (HR: 7.36, CI 95%: 1.18-45.99, p = 0.038) remained as independent predictors.

CONCLUSIONS

Adults with ccTGA and an SRV are burdened with significant morbidity and mortality. Predictors for mortality are NYHA class and subpulmonary left ventricular function.