Transcatheter closure of atrial septal defect in adults: time-course of atrial and ventricular remodeling and effects on exercise capacity

Sigurdur S Stephensen,Ulf Thilén,Marcus Carlsson,Ellen Ostenfeld,Hakan Arheden,Shelby Kutty,Katarina Steding-Ehrenborg

doi:10.1007/s10554-019-01647-0

Abstract

Investigate ventricular and atrial remodeling following atrial septal defect (ASD) closure and examine if pulmonary-to-systemic flow ratio (QP/QS) and right ventricular (RV) volume predict improvement, determined as percentage of predicted oxygen uptake (VO2%). Long-term cardiovascular magnetic resonance (CMR) data on atrial and ventricular remodeling after ASD-closure is limited and treatment effect on exercise capacity is debated. Sixteen patients undergoing transcatheter ASD closure and 16 age and sexmatched controls were studied. CMR was performed before treatment, the day after and 3 and 12 months later. Exercise test with gas analysis was performed before and 12 months after treatment. QP/QS decreased from 2.1 ± 0.5 to 1.4 ± 0.3 at day 1 and 1.1 ± 0.1 at 3 and 12 months. Left ventricular (LV) volumes increased and normalized on day 1 whereas left atrial volumes were unchanged. RV and right atrial volumes decreased the first 3 months. LV and RV volumes had not equalized at 12 months (RV/LV ratio 1.2 ± 0.1, P < 0.01) and RV ejection fraction remained decreased compared to controls. Improvement of VO2% after ASD closure (P < 0.01) was inversely related to QP/QS at rest (r = − 0.56, P < 0.05) but unrelated to RV end-diastolic volume (P = 0.16). Following transcatheter ASD closure, LV adaptation is rapid and RV adaptation is prolonged, with decreased systolic RV function. Patients with smaller shunts had larger improvement in VO2% suggesting patients with defects of borderline hemodynamic significance might benefit from closure. This may be due to impaired LV diastolic function influencing shunt size and exercise capacity following ASD closure.

Highlights

The indications for surgical or transcatheter closure of secundum atrial septal defects (ASD) are enlargement of the right ventricle (RV) or symptoms including exercise intolerance, fatigue or dyspnea [1]
Controls were matched for age and sex and had similar body surface area (BSA) and heart rate compared to patients at 12 months follow up (Table 1)
The time course of ventricular remodeling after ASD closure is faster in the left ventricle (LV) compared to the RV

Summary

Introduction

The indications for surgical or transcatheter closure of secundum atrial septal defects (ASD) are enlargement of the right ventricle (RV) or symptoms including exercise intolerance, fatigue or dyspnea [1]. Limited data on atrial and ventricular remodeling after ASD closure is available from echocardiography [3] but more comprehensive longterm follow-up information ( > 6 months) on left and right atrial and ventricular volumes with CMR is unavailable. Studies with CMR have found residual RV enlargement compared to the left ventricle (LV) at 6 months [4]. Schoen et al found 30% of patients to have enlarged RV at 12 month follow-up [5]. The long-term adaptation of both ventricles and atria following ASD closure is unknown.

Objectives

Methods

Results

Discussion

Conclusion