Assessment of long-term cardiac adaptation in adult patients with type II atrial septal defect : A cardiovascular magnetic resonance (CMR) study.

OBJECTIVES: In type II atrial septal defect (ASD) patients, the left-to-right (LR) shunt causes adaptation of the heart and circulation. The study objective was to evaluate with cardiovascular magnetic resonance imaging (CMR) the impact of LR shunt on left (LV) and right ventricular (RV) volumes, function, and myocardial strain. METHODS: Thirty-five patients (42 ± 17 years, 17 male) were compared to a control group (n = 40). Cine imaging was used to calculate ventricular volumes and ejection fraction (EF), global longitudinal (GLS) and circumferential strain (GCS), and longitudinal free wall (FWS) and interventricular septal (IVS) strain. Phase-contrast imaging was used to calculate pulmonary flow to systemic flow ratio (Qp/Qs). RESULTS: The LR shunt (Qp/Qs 2.2 ± 0.6) resulted in larger RV end-diastolic volume (EDVi) (152 ± 42 vs 82 ± 11 ml/m2), lower LV EDVi (72 ± 16 vs 83 ± 9 ml/m2), and higher RV/LV EDVi ratio (2.2 ± 0.5 vs 1.0 ± 0.1) than controls (all p < 0.001). Functionally, stroke volumes were larger in RV and lower in LV (both p < 0.001) with a strong trend toward lower RV EF in patients (p = 0.08). The LR shunt negatively impacted RV GLS (p = 0.03) but not RV GCS. Longitudinal IVS but not RV FWS were significantly lower in patients, i.e., p < 0.001, of longitudinal IVS. Shunt severity correlated with RV size and stroke volume, right atrial size, and pulmonary trunk diameter (all p < 0.001), but not with functional nor strain parameters. CONCLUSION: Long-term cardiac adaptation in ASD patients, with RV overfilling and LV underfilling, has a negative impact on systolic RV performance, a phenomenon which likely can be attributed to longitudinal dysfunction of the interventricular septum. KEY POINTS: • An LR shunt in type II ASD patients causes cardiac remodeling characterized by RV overfilling and conversely underfilling of the left ventricle. • At the long term, there is evidence of systolic dysfunction of the right ventricle in this group of patients. • Septal dysfunction underlies the observed impairment in RV function.

Pulmonary hypertension in patients with a subaortic right ventricle: prevalence, impact and management.

OBJECTIVE: This study sought to determine the prevalence, predictors, prognostic relevance and evolution of pulmonary hypertension (PH) (mean pulmonary artery pressure ≥25 mm Hg) in adult patients with a subaortic right ventricle (RV) in a biventricular circulation (2V-RV). METHODS: We analysed retrospective data from patients with 2V-RV undergoing cardiac catheterisation in our centre between 2000 and 2018. Echocardiographic assessment of subpulmonary ventricular pressures (left ventricular systolic pressure (LVSP)), age and B-type natriuretic peptide (BNP) were assessed as PH screening tools. Kaplan-Meier curves examined time to a composite outcome of death, transplant or ventricular assist device (VAD). Data from repeat catheterisations were analysed to evaluate PH changes over time, including the effects of therapy. RESULTS: A total of 141 patients (median age 39 (IQR 33-45) years, 68% men) underwent 191 cardiac catheterisations. At baseline, 55% had PH (isolated postcapillary 24%, combined precapillary and postcapillary 26% and precapillary 5%). BNP (area under the curve 0.80; 95% CI 0.72 to 0.88; p<0.0001), but not age at catheterisation or echocardiographic estimates of LVSP were associated with the presence of PH. The absence of PH and BNP <100 pg/mL discriminated a subgroup at very low risk during short-term (2.5 (1.3-3.9) years) follow-up (p<0.0001). Diuretics, milrinone and VAD improved haemodynamics over time. CONCLUSION: PH is prevalent in patients with 2V-RV even when asymptomatic. It is difficult to identify by echocardiography and most importantly, is strongly associated with adverse outcomes. PH affects prognosis and transplant options for this patient group and yet is often amenable to treatment. Awareness of these results ought to lower the threshold for invasive haemodynamic assessment and may change the management of failing patients with 2V-RV.

Serial pulmonary vascular resistance assessment in patients late after ventricular septal defect repair.

BACKGROUND: The long-term evolution of pulmonary vascular resistance (PVR) after ventricular septal defect (VSD) repair is unknown. This study serially evaluated resting and exercise PVR after VSD repair in childhood. METHODS: Patients were enrolled from the outpatient Adult Congenital Heart Disease clinic of the University Hospitals Leuven and compared to age- and gender-matched controls. Participants underwent resting and exercise echocardiography and cardiopulmonary exercise testing at baseline and follow-up. Total PVR was calculated as the ratio of mean pulmonary artery pressure (mPAP) to cardiac output (CO). The slope of the mPAP-CO curve (exercise PVR) was obtained using linear regression analysis. RESULTS: Twenty-seven patients (mean age 31 ±â€¯7 years, 70% male) and 18 controls were included. At baseline, patients had larger right ventricular (RV) end-diastolic areas (10 ±â€¯2 vs 9 ±â€¯1 cm2/m2, p = 0.001) and lower tricuspid annular plane systolic excursion (TAPSE) (17 (17-19) vs 26 (22-28) mm, p < 0.001). After 1.1 (1.0-1.5) years follow-up, similar differences in RV areas and TAPSE were found. Patients reached lower peak workload and cardiac index compared to controls at each time point. Peak total PVR was higher (Baseline: 2.7 ±â€¯0.8 vs 2.2 ±â€¯0.3 mm Hg/L/min, p = 0.005; Follow-up: 2.9 ±â€¯0.9 vs 2.1 ±â€¯0.3 mm Hg/L/min, p < 0.001) and the mPAP-CO slope was steeper (Baseline: 2.2 ±â€¯0.8 vs 1.7 ±â€¯0.3 mm Hg/L/min, p = 0.008; Follow-up: 2.5 ±â€¯0.9 vs 1.6 ±â€¯0.3 mm Hg/L/min, p < 0.001) in patients. The mPAP-CO slope in patients correlated inversely with peak oxygen uptake (R = -0.41 and - 0.45, p = 0.036 and 0.022, baseline and follow-up, respectively). CONCLUSION: Despite repair, VSD patients seem to show altered pulmonary hemodynamics and RV impairment at rest and exercise, supporting life-long follow-up.

Functional and haemodynamic assessment of mild-to-moderate pulmonary valve stenosis at rest and during exercise.

OBJECTIVE: In adult patients with mild-to-moderate pulmonary valve (PV) stenosis, exercise capacity and haemodynamics have not been extensively studied, although regular exercise is recommended. Therefore, we aimed to assess exercise capacity to study the increase in PV gradient during exercise and to evaluate the impact of this increased pressure load on the RV. METHODS: Nineteen patients (8 female; 29±6.4 years) with isolated mild-to-moderate PV stenosis and no prior cardiac interventions were consecutively enrolled from the outpatient clinic of adult congenital heart disease. All patients underwent cardiopulmonary exercise testing, transthoracic echocardiography and bicycle stress echocardiography. Results for exercise testing were compared with age-matched and gender-matched control patients. RESULTS: In the studied population, resting heart rate (89±11 vs 75±14 bpm; p=0.001), peak power (199±66 vs 263±68 W; p=0.006); peak VO2 (31.2±9.9 vs 39±7.4 mL/kg/min; p=0.011); oxygen uptake efficiency slope (2430±913 vs 3292±943(mL/min)/(L/min); p=0.007) and VE/VCO2 slope (26.8±5.2 vs 22.6±4.3; p=0.01) differed significantly from controls. A linear increase of peak PV gradient with increasing flow was observed in the pooled dataset (Pearson's R=0.947; p<0.0001) and slopes identical as for control patients were obtained for the oxygen pulse-workload relationship. Right heart morphology and function were preserved in the studied patients. CONCLUSIONS: Patients with mild-to-moderate PV stenosis have decreased exercise capacity. A linear increase in PV gradient with flow suggests a fixed valve area throughout the exercise. Although systolic RV pressure load increases during exercise, good ventricular performance was observed without signs of functional or morphological changes of the right heart. CLINICAL TRIAL NUMBER: NCT01444222.