The role for cardiopulmonary exercise testing in patients with atrial septal defects: A review

A sudden right-to-left shunt: the importance of evaluating patent foramen ovale during exercise

A 55-year-old male affected by heart failure with reduced ejection fraction and a history of a transient cerebrovascular accident was accepted to the Cardiology Department for worsening dyspnea. A cardiopulmonary exercise test was performed after therapy optimization to further evaluate exercise intolerance. A rapid increase in the minute ventilation/carbon dioxide production slope, end-tidal oxygen pressure, and respiratory exchange ratio, with a concomitant decrease in end-tidal carbon dioxide pressure and oxygen saturation, were observed during the test. These findings indicate exercise-induced pulmonary hypertension leading to a right-to-left shunt. Subsequent echocardiography with a bubble test unveiled the presence of an unknown patent foramen ovale. It is, therefore, necessary to exclude a right-to-left shunt by cardiopulmonary exercise testing, particularly in patients predisposed to develop pulmonary hypertension during exercise. Indeed, this eventuality might potentially provoke severe cardiovascular embolisms. However, the patent foramen ovale closure in patients with heart failure with reduced ejection fraction is still debated because of its potential hemodynamic worsening.

Preoperative coupling between right ventricle and pulmonary vasculature is an important determinant of residual symptoms after the closure of atrial septal defect

PURPOSES

The closure of atrial septal defect (ASD) is associated with a significant reduction in right ventricular (RV) overload and an improvement in functional capacity in most adults with ASD. However, a subset of patients remains symptomatic even after closure due to therapeutic delay. To date, no clinically robust preoperative predictor of postoperative residual symptoms has been clearly identified.

METHODS

In this study, 120 adult patients with ASD and 39 controls were investigated. As an index of RV myocardial deformation, RV global longitudinal strain (RV-GLS) was evaluated. The degree of coupling between RV and pulmonary artery (PA) was quantified by the tricuspid annular plane systolic excursion (TAPSE) divided by the PA systolic pressure (PASP).

RESULTS

Compared to controls, baseline RV-GLS was significantly greater (- 27 ± 7 vs. - 23 ± 5%, P = 0.02) and TAPSE/PASP ratio was severely impaired (0.8 ± 0.3 vs. 2.1 ± 1.6 mm/mmHg, P < 0.01) in ASD patients. At 6 months after closure, 15 patients (12.5%) remained symptomatic. In patients without residual symptoms, TAPSE/PASP ratio significantly improved from 0.9 ± 0.3 to 1.0 ± 0.6 mm/mmHg (P = 0.02), and RV-GLS normalized (from - 28 ± 11 to - 24 ± 7%, P < 0.01) after closure. However, RV-GLS and TAPSE/PASP ratio showed no significant change in ASD patients with residual symptoms. On multivariate analysis, preoperative TAPSE/PASP ratio (odds ratio [OR] 0.034, 95% confidence interval [CI] 0.000-0.604, P = 0.03) and pulmonary vascular resistance index ([PVRI], OR 1.011, 95% CI 1.000-1.021, P < 0.05) were associated with the postoperative symptomatic status.

CONCLUSION

In terms of integrated assessment of the RV-PA unit, preoperative TAPSE/PASP ratio and PVRI were important determinants of residual symptoms after ASD closure.

Validation of intracardiac shunt using thoracic bioimpedance and inert gas rebreathing in adults before and after percutaneous closure of atrial septal defect in a cardiology research unit: study protocol

INTRODUCTION

Intrathoracic shunt quantification is a major factor for appropriate clinical management of heart and pulmonary diseases. Intracardiac shunts quantified by pulmonary to systemic output ratio (Qp/Qs) are generally assessed by Doppler echocardiography, MRI or catheterisation. Recently, some authors have suggested the concomitant use of thoracic bioimpedance (TB) and inert gas rebreathing (IGR) techniques for shunt quantification. The purpose of this study is to validate the use of this approach under conditions where shunt fraction is directly quantified such as in patients with isolated atrial septal defect (ASD).

METHODS AND ANALYSIS

This trial is a prospective, observational single-centre, non-blinded study of adults seen for percutaneous closure of ASD. Qp/Qs ratio will be directly measured by Doppler echocardiography and direct Fick. IGR and TB will be used simultaneously to measure the cardiac output before and after closure: the ratio of outputs measured by IGR and TB reflecting the shunt fraction. The primary outcome will be the comparison of shunt values measured by TB-IGR and Doppler echocardiography.

ETHICS AND DISSEMINATION

The study has been approved by an independent Research Ethics Committee (2017-A03149-44 Fr) and registered as an official clinical trial. The results will be published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT03437148; Pre-results.

Atrial septal defect and exercise capacity: value of cardio-pulmonary exercise test in assessment and follow-up

Nearly four decades ago, the World Health Organization stated that functional capacity explorations best reflected the impact of a chronic disease on quality of life. Today, cardio-pulmonary exercise test (CPET) is recommended in the follow-up of patients with congenital heart diseases (CHDs). Indeed, the maximum oxygen uptake (VO_2max) and the ventilatory efficiency (VE/VCO₂ slope) correlate with both the prognosis and the quality of life in this population. Atrial septal defects (ASDs) represent the second most frequent CHD and are usually considered as simple CHDs. However, the exercise capacity of ASD patients may be impaired. Therefore, the CPET provides important information in assessment and follow-up of patients with ASDs, for both children and adults. Exercise capacity of patients with unrepaired ASDs depends on the importance of the shunt, the right ventricular (RV) function and volume overload, the level of pulmonary arterial pressure, and the occurrence of arrhythmias. For repaired ASDs, exercise capacity also depends on the delay before closure and the type of procedure (catheter or surgery). In most cases, the exercise capacity is nearly normal and CPET contributes to promote sports participation. In addition, a regular CPET follow-up is necessary to evaluate the occurrence, severity and physiological mechanisms of comorbidities, i.e., heart failure, pulmonary hypertension and arrhythmia. Furthermore, CPET follow-up in patients with ASDs may detect early onset of muscular deconditioning, for which cardiac rehabilitation may be considered.