Diastolic ventricular interaction in patients after atrial switch for transposition of the great arteries: A speckle tracking echocardiographic study

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.

Heart failure with reduced and preserved ejection fraction in adult congenital heart disease

Heart failure with reduced ejection fraction (HFrEF) is common in patients with adult congenital heart disease. Many of the most common congenital defects have a high prevalence of HFrEF, including left-sided obstructive lesions (aortic stenosis, coarctation of the aorta, Shone complex), tetralogy of Fallot, Ebstein anomaly, lesions in which there is a systemic right ventricle, and lesions palliated with a Fontan circulation. However, heart failure with preserved ejection fraction (HFpEF) is also prevalent in all these lesions. Comprehensive evaluation includes physical exam, biomarkers, echocardiography and advanced imaging, exercise stress testing, and, in some cases, invasive hemodynamics. Guideline-directed medical therapy for HFrEF can be applied to left-sided lesions and may be considered on an individual basis for systemic right ventricle and single-ventricle patients. Medical therapy is limited for HFpEF. However, in both HFrEF and HFpEF, ventricular dyssynchrony and arrhythmias play an important role, and medications for rhythm control, ablation, and cardiac resynchronization therapy should be considered. Finally, aggressive management of cardiovascular risk factors and comorbidities, including, but not limited to, hypertension, obesity, diabetes, dyslipidemia, and obstructive sleep apnea, cannot be overemphasized.

Prevalence of pulmonary hypertension in adults after atrial switch and role of ventricular filling pressures

OBJECTIVE

To assess the prevalence of elevated systemic right ventricular (sRV) end-diastolic pressure and pulmonary arterial hypertension in adults with transposition of the great arteries (TGA) who have undergone atrial switch operation.

METHODS

Forty-two adults (aged ≥18 years) with complete TGA and atrial switch palliation undergoing cardiac catheterisation between 2004 and 2018 at Mayo Clinic, MN, were identified. Clinical, echocardiographic and invasive haemodynamic data were abstracted from the medical charts and procedure logs.

RESULTS

Mean age was 37.6±7.9 years; 28 were male (67%). The Mustard operation was performed in 91% of individuals. Mean estimated sRV ejection fraction by echocardiography was 33.3%±10.9% and ≥moderate tricuspid (systemic atrioventricular valve) regurgitation was present in 15 patients (36%). Mean sRV end-diastolic pressure was 13.2±5.4 mm Hg. An sRV end-diastolic pressure >15 mm Hg was present in 35% of individuals whereas a pulmonary artery wedge pressure (PAWP) >15 mm Hg was seen in 59%. Mean pulmonary artery pressure ≥25 mm Hg was seen in 47.5% of patients with PAWP being >15 mm Hg in all but one patient.

CONCLUSION

In adults after atrial switch, elevated sRV end-diastolic pressure was present in only one-third of patients whereas increased PAWP was seen in almost 60%. These findings are most likely related to a combination of decreased pulmonary atrial (functional left atrium) compliance and, in a subset of patients, pulmonary venous baffle obstruction. Elevation in pulmonary pressures was highly prevalent with concomitant elevation in PAWP being present in essentially all patients.

Differential myocardial fibrosis of the systemic right ventricle and subpulmonary left ventricle after atrial switch operation for complete transposition of the great arteries

Background

This study aimed to assess diffuse myocardial fibrosis of the systemic right ventricle and subpulmonary left ventricle in patients after Senning or Mustard operation for complete transposition of the great artery (TGA) using cardiac magnetic resonance (CMR) T1 mapping.

Methods

Thirty-one adult TGA patients after Senning (n = 24) or Mustard (n = 7) operation were studied at the age of 33.3 ± 4.0 years. Systemic right ventricular (RV) and subpulmonary left ventricular (LV) volumes, ejection fraction, and myocardial T1 values and extracellular volume fraction (ECV) were determined using CMR.

Results

The RV and LV ejection fractions were 47.0 ± 10.9% and 61.3 ± 7.4%, respectively. Compared to published normative values, patients had significantly greater RV and LV native T1 and ECV values (all p < 0.001). For each of the basal, mid, and apical segments, the LV native T1 and ECV values were significantly greater in the left than the right ventricle (all p < 0.05). There is a significant trend on progressive increase in ECV value from the basal towards the apical segments in both the right (p = 0.002) and the left (p < 0.001) ventricle. Modestly strong correlations were found between RV and LV native T1 (r = 0.60, p < 0.001) and ECV (r = 0.49, p = 0.005) values but not with ejection fractions of the respective ventricles.

Conclusions

Differential myocardial fibrosis, with greater involvement of the subpulmonary left ventricle than the systemic right ventricle, is present in patients with TGA after atrial switch operation. Associations between the magnitude of RV and LV fibrosis suggests adverse ventricular-ventricular interaction at the cardiac extracellular matrix level.

Frontal QRS-T angle and ventricular mechanics in congenital heart disease

BACKGROUND

The QRS-T angle has been associated with adverse cardiovascular events and sudden cardiac deaths. We determined frontal QRS-T angle in patients with complete transposition of the great arteries (TGA) after atrial switch operation and repaired tetralogy of Fallot (TOF) and explored its relationships with ventricular mechanics.

METHODS

Thirty TGA patients aged 32.3 ± 4.4 years after atrial switch operation and 47 repaired TOF patients aged 28.7 ± 6.0 years were studied. The frontal planar QRS-T angle and QRS duration were measured from 12-lead electrocardiograms. Right (RV) and left ventricular (LV) strain parameters were determined using speckle tracking echocardiography.

RESULTS

Compared with TOF patients, TGA patients after atrial switch operation had significantly greater frontal QRS-T angle (136.3° ± 43.5° vs 74.5° ± 59.6°, p < 0.001), greater prevalence of QRS-T angle ≥ 100° (83.3% vs 29.8%, p < 0.001), and showed progressive increase in QRS-T angle over a duration of 3.3 ± 1.0 years (p = 0.035). The QRS-T angle correlated positively with QRS duration in both the TGA (r = 0.61, p < 0.001) and TOF (r = 0.30, p < 0.043) groups. Among TGA patients, QRS-T angle was found to correlate negatively with systemic RV global longitudinal strain (r = - 0.49, p = 0.007), early diastolic strain rate (r = - 0.41, p = 0.026), and fractional area change (r = - 0.38, p = 0.045), but not subpulmonary LV strain indices. By contrast, among repaired TOF patients, there were no significant correlations between QRS-T angle and systemic and subpulmonary ventricular strain indices (all p > 0.05).

CONCLUSION

Increased frontal QRS-T angle is prevalent in TGA patients after atrial switch operation and is related to worse systemic RV mechanics.

Emerging clinical applications of strain imaging and three-dimensional echocardiography for the assessment of ventricular function in adult congenital heart disease

Management of congenital heart disease (CHD) in adults (ACHD) remains an ongoing challenge due to the presence of residual hemodynamic lesions and development of ventricular dysfunction in a large number of patients. Echocardiographic imaging plays a central role in clinical decision-making and selection of patients who will benefit most from catheter interventions or cardiac surgery.. Recent advances in both strain imaging and three-dimensional (3D)-echocardiography have significantly contributed to a greater understanding of the complex pathophysiological mechanisms involved in CHD. The aim of this paper is to provide an overview of emerging clinical applications of speckle-tracking imaging and 3D-echocardiography in ACHD with focus on functional assessment, ventriculo-ventricular interdependency, mechanisms of electromechanical delay, and twist abnormalities in adults with tetralogy of Fallot (TOF), a systemic RV after atrial switch repair or in double discordance ventricles, and in those with a Fontan circulation.

Improved Exercise Performance in Patients With Tricuspid Atresia After the Fontan-Björk Modification With Pulsatile Systolic Pulmonary Flow

BACKGROUND

After the Fontan-Björk modification for tricuspid atresia, some patients show pulsatile systolic pulmonary flow. We compared the hemodynamic findings and the clinical presentation of patients with and without pulsatile systolic flow after atrioventricular connection.

METHODS

According to the pulmonary flow pattern by pulsed-wave Doppler assessment of transthoracic echocardiography, 41 patients after atrioventricular connection were divided into two groups: patients who showed dominant pulsatile systolic pulmonary flow (group P, n = 11), and patients who did not (group N, n = 30).

RESULTS

Mean follow-up time was 27.8 ± 4.7 years in group P and 25.3 ± 3.8 years in group N (p = 0.1). Patients in group P had significantly less frequently catheter ablation procedures for tachyarrhythmia (9% versus 50%, p = 0.03). No patient in group P had had cardiac decompensation, whereas 7 patients (23%) in group N had had an episode of cardiac decompensation (p = 0.08). Cardiopulmonary exercise testing revealed that patients in group P showed higher oxygen uptake compared with patients in group N (25.0 ± 7.3 versus 19.6 ± 6.0 mL · kg(-1) · min(-1), p = 0.03). Patients in group P showed higher systolic pulmonary artery pressure (21.3 ± 8.4 versus 16.8 ± 4.5 mm Hg, p = 0.05), higher right ventricular end-diastolic volume index (88.6 ± 30.2 versus 50.3 ± 28.5 mL · L(-1) · m(-2), p = 0.03), and higher right ventricle to left ventricle ratio of end-diastolic volume index (1.4 ± 0.6 to 0.7 ± 0.3, p = 0.01).

CONCLUSIONS

Patients with pulsatile systolic flow in the pulmonary artery had better hemodynamic and better exercise performance compared with patients without pulsatile systolic flow after atrioventricular connection. A sufficient volume and function of the right ventricle is a prerequisite to create pulsatile systolic flow.

Systemic Right Ventricular Fibrosis Detected by Cardiovascular Magnetic Resonance Is Associated With Clinical Outcome, Mainly New-Onset Atrial Arrhythmia, in Patients After Atrial Redirection Surgery for Transposition of the Great Arteries

Background—

We hypothesized that fibrosis detected by late gadolinium enhancement (LGE) cardiovascular magnetic resonance predicts outcomes in patients with transposition of the great arteries post atrial redirection surgery. These patients have a systemic right ventricle (RV) and are at risk of arrhythmia, premature RV failure, and sudden death.

Methods and Results—

Fifty-five patients (aged 27±7 years) underwent LGE cardiovascular magnetic resonance and were followed for a median 7.8 (interquartile range, 3.8–9.6) years in a prospective single-center cohort study. RV LGE was present in 31 (56%) patients. The prespecified composite clinical end point comprised new-onset sustained tachyarrhythmia (atrial/ventricular) or decompensated heart failure admission/transplantation/death. Univariate predictors of the composite end point (n=22 patients; 19 atrial/2 ventricular tachyarrhythmia, 1 death) included RV LGE presence and extent, RV volumes/mass/ejection fraction, right atrial area, peak V o 2 , and age at repair. In bivariate analysis, RV LGE presence was independently associated with the composite end point (hazard ratio, 4.95 [95% confidence interval, 1.60–15.28]; P =0.005), and only percent predicted peak V o 2 remained significantly associated with cardiac events after controlling for RV LGE (hazard ratio, 0.80 [95% confidence interval, 0.68–0.95]; P =0.009/5%). In 8 of 9 patients with >1 event, atrial tachyarrhythmia, itself a known risk factor for mortality, occurred first. There was agreement between location and extent of RV LGE at in vivo cardiovascular magnetic resonance and histologically documented focal RV fibrosis in an explanted heart. There was RV LGE progression in a different case restudied for clinical indications.

Conclusions—

Systemic RV LGE is strongly associated with adverse clinical outcome especially arrhythmia in transposition of the great arteries, thus LGE cardiovascular magnetic resonance should be incorporated in risk stratification of these patients.

Functional assessment for congenital heart disease

Significant improvement in survival of children with congenital cardiac malformations has resulted in an increasing population of adolescent and adult patients with congenital heart disease. Of the long-term cardiac problems, ventricular dysfunction remains an important issue of concern. Despite corrective or palliative repair of congenital heart lesions, the right ventricle, which may be the subpulmonary or systemic ventricular chamber, and the functional single ventricle are particularly vulnerable to functional impairment. Regular assessment of cardiac function constitutes an important aspect in the long-term follow up of patients with congenital heart disease. Echocardiography remains the most useful imaging modality for longitudinal monitoring of cardiac function. Conventional echocardiographic assessment has focused primarily on quantification of changes in ventricular size and blood flow velocities during the cardiac cycles. Advances in echocardiographic technologies including tissue Doppler imaging and speckle tracking echocardiography have enabled direct interrogation of myocardial deformation. In this review, the issues of ventricular dysfunction in congenital heart disease, conventional echocardiographic and novel myocardial deformation imaging techniques, and clinical applications of these techniques in the functional assessment of congenital heart disease are discussed.

Circulating annexin A5 levels after atrial switch for transposition of the great arteries: relationship with ventricular deformation and geometry

Background

Inflammatory cytokines, cardiomyocyte apoptosis, and altered collagen turnover may contribute to unfavourable ventricular remodeling. This unfavourable ventricular remodelling is well documented in patients after atrial switch operation for complete transposition of the great arteries. We therefore tested if levels of circulating markers of inflammation, apoptosis, collagen synthesis, and extracellular matrix degradation are altered in patients after atrial switch operation for transposition of the great arteries.

Methods and Results

Circulating tumour necrosis factor (TNF)-α, annexin A5 (AnxA5), carboxy-terminal propeptide of type I procollagen (PICP), amino-terminal propeptide of type III procollagen (PIIINP), matrix metalloproteinase-1 (MMP-1), and tissue inhibitor of metalloproteinase-1 (TIMP-1) levels were determined in 27 patients aged 25.2±3.1 years and 20 controls. Ventricular myocardial deformation and left ventricular eccentricity index (EI) were determined by speckle tracking and two-dimensional echocardiography, respectively. Compared with controls, patients had significantly higher circulating AnxA5 (p<0.001) and TNF-α (p = 0.018) levels, but similar PICP, PIIINP, MMP-1 and TIMP-1 levels. For the whole cohort, plasma AnxA5 correlated with serum TNF-α (p = 0.002), systemic ventricular global longitudinal strain (GLS) and systolic and early diastolic strain rate (all p<0.001), and subpulmonary ventricular GLS and early diastolic strain rate (both p<0.001). In patients, plasma AnxA5 level correlated positively with subpulmonary ventricular EI (p = 0.027). Multiple linear regression analysis identified systemic ventricular GLS (β = −0.50, p<0.001) and serum TNF-α (β = 0.29, p = 0.022) as significant correlates of plasma AnxA5.

Conclusions

Elevated plasma AnxA5 level in patients after atrial switch operation is associated with impaired systemic myocardial deformation, increased subpulmonary ventricular eccentricity, and increased serum TNF-α level.

Right ventricular function with standard and speckle-tracking echocardiography and clinical events in adults with D-transposition of the great arteries post atrial switch

BACKGROUND

The prognostic value of deformation parameters of the systemic right ventricle in adults with D-transposition of the great arteries and prior atrial switch has not been reported.

METHODS

Sixty-four adults with D-transposition of the great arteries and prior atrial switch (mean age, 29 ± 6 years; 22 women; mean right ventricular [RV] fractional area change, 22.9 ± 7.5%; 31 with pacemakers at baseline) and no histories of heart failure or ventricular tachycardia were prospectively evaluated. Global longitudinal strain (GS), global systolic strain rate (GSRs), and global early diastolic strain rate (GSRe) of the right ventricle were measured using speckle tracking from apical views and compared with standard parameters of RV function (fractional area change, tricuspid annular plane systolic excursion, tissue Doppler velocities, and isovolumic acceleration) for association with and potential prediction of clinical events, defined as incident stage C heart failure or ventricular tachycardia.

RESULTS

Baseline RV GS, GSRs, and GSRe were -12.5 ± 3.0%, -0.59 ± 0.14 sec(-1), and 0.68 ± 0.22 sec(-1), respectively. After a median of 2.4 years (interquartile range, 1.5-4.1 years), 12 patients (19%) presented with clinical events (heart failure in 11 patients, ventricular tachycardia in one patient). In Cox models, RV GS had the strongest association with clinical events (hazard ratio [HR] per 1%, 1.35; 95% confidence interval [CI], 1.14-1.58; P < .001), followed by GSRs (HR per 0.01 sec(-1), 1.06; 95% CI, 1.02-1.11; P = .006), GSRe (HR per -0.01 sec(-1), 1.04; 95% CI, 1.00-1.07; P = .031), and fractional area change (HR per -1%, 1.08; 95% CI, 1.00-1.17; P = .047). Other measures of RV function were not significantly associated with risk for events. In receiver operating characteristic analysis, RV GS ≥ -10% optimally predicted future events (C = 0.83; 95% CI, 0.71-0.91; P < .001).

CONCLUSIONS

Reduced longitudinal GS of the systemic right ventricle is associated with increased risk for clinical events among patients with D-transposition of the great arteries and prior atrial switch.