Subsequent shunt closure after targeted medical therapy can be an effective strategy for secundum atrial septal defect with severe pulmonary arterial hypertension: two case reports : strategy for ASD with severe PAH

Pulmonary arterial hypertension with left to right shunts: When to treat and/or close?

Pulmonary arterial hypertension (PAH) is defined as increase in mean pulmonary arterial pressure and pulmonary vascular resistance (PVR). It can be associated with congenital heart disease (CHD) with the following subtypes: 1) uncorrected left-to-right (L-R) intracardiac shunt leading to overload of the pulmonary circulation and a progressive increase of PVR; 2) Eisenmenger syndrome, appearing when a large post-tricuspid shunt is left uncorrected and pulmonary vascular disease (PVD) is severe, so the shunt becomes bidirectional or right-to-left, causing cyanosis; 3) PAH after shunt closure, when PVR arises after a defect correction; and 4) PAH associated with small or coincidental defects. While the treatment of patients with Eisenmenger syndrome is well established, the treatment of patients with PAH in whom there is a L-R shunt (with no cyanosis) remains unclear and requires expertise. In such patients, correction of the defect may be contemplated if there is mild PVD and a significant L-R shunt. Others may benefit from a "treat and repair" strategy, which involves the use of PAH therapy to achieve a drop in PVR, with the aim of achieving operability criteria. Cardiac catheterization is at the center of the evaluation and follow-up of these patients, collecting "baseline" data and providing the opportunity to challenge the pulmonary circulation, manipulate the loading status, or temporarily occlude the defect. This article provides a detailed overview of the pathophysiology and treatment options for patients with PAH associated with a L-R congenital shunt, including current approaches to operability and the use of PAH therapies.

The efficacy of the treat-repair-treat strategy for severe pulmonary arterial hypertension associated with congenital heart disease: a meta-analysis

BACKGROUND

This meta-analysis was conducted to evaluate the efficacy of the treat-repair-treat (TRT) strategy in the treatment of severe pulmonary arterial hypertension with congenital heart disease (PAH-CHD).

METHODS

PubMed, EMBASE, Cochrane and Web of Science online databases were searched by two independent investigators for studies that used the TRT strategy for PAH-CHD, and the retrieved studies were reviewed by a third investigator. The main outcomes were pulmonary artery pressure (PAP), pulmonary vascular resistance (PVR), 6-minute walk distance (6MWD), and transcutaneous oxygen saturation (SpO2). The changes were compared between follow-up and baseline. Stata version 14.0 was used for data analysis. A random-effects model was selected for meta-analysis. Subgroup analysis and meta-regression were used to find the source of heterogeneity.

RESULTS

A total of 335 patients from 9 single-arm studies were included. Meta-analysis showed significant reductions in PAP and PVR and improvements in 6MWD and SpO2 (PAP: SMD -2.73 95% CI -2.97, - 2.50 p = < 0.001; PVR: SMD -1.27 95% CI -1.53, - 1.02 p = < 0.001; 6MWD: SMD 1.88 95% CI 1.49, 2.27 p = < 0.001; SpO2: SMD 3.72 95% CI 3.13, 4.32 p = < 0.001). Subgroup analysis showed that younger patients had better efficacy, and the change in SpO2 was an indication for patient selection. The combined mortality rate was 5% at follow-up.

CONCLUSIONS

In this meta-analysis, we demonstrated that the TRT strategy may have positive effects on haemodynamics and cardiac function in patients with severe PAH-CHD at short-term follow-up. Our analysis suggests that changes in age and SpO2 may be related to patient prognosis.

TRIAL REGISTRATION

The protocol was registered on the PROSPERO website with the registration number CRD42022366552. The relevant registration information can be obtained from the website https://www.crd.york.ac.uk/prospero/#searchadvanced .

Management of systemic to pulmonary shunts and elevated pulmonary vascular resistance

Background

Repair of systemic to pulmonary shunts is timed to prevent the development of irreversible pulmonary vascular disease, including in patients with other factors contributing to pulmonary hypertension. This study assessed outcomes of an individualised strategy for managing patients with mild-moderately elevated pulmonary vascular resistance (PVR) deemed borderline eligible for repair.

Methods

A retrospective chart review was conducted of patients with systemic to pulmonary shunts and baseline indexed PVR (PVRi) ≥3 WU·m2 treated at a single centre from 1 January 2005 to 30 September 2019. Data included demographics, World Health Organization functional class (WHO FC), medications and haemodynamic data at baseline and serial follow-up.

Results

30 patients (18 females) met criteria for inclusion. Median age at diagnosis of pulmonary arterial hypertension was 1.3 years (range 0.03-54 years) and at surgery was 4.1 years (range 0.73-56 years). Median follow-up time was 5.8 years (range 0.2-14.6 years) after repair. Most patients received at least one targeted pulmonary arterial therapy prior to repair and the majority (80%) underwent fenestrated shunt closure. There was a significant decrease in mean pulmonary arterial pressure (mPAP) (p<0.01), PVRi (p=0.0001) and PVR/systemic vascular resistance (p<0.01) between baseline and preoperative catheterisation and a decrease in PVRi (p<0.005), mPAP (p=0.0001) and pulmonary to systemic flow ratio (p<0.03) from baseline to most recent catheterisation. WHO FC improved from FC II-III at baseline to FC I post repair in most patients (p<0.003).

Conclusions

In carefully selected patients with systemic to pulmonary shunts and elevated PVR considered borderline for operability, the use of preoperative targeted therapy in conjunction with fenestrated or partial closure of intracardiac shunts is associated with improvement in WHO FC and clinical outcomes.

Efficacy of treat-and-repair strategy for atrial septal defect with pulmonary arterial hypertension

OBJECTIVE

Therapeutic strategies for atrial septal defect (ASD) with severe pulmonary arterial hypertension (PAH) are controversial. This study aimed to evaluate the efficacy of PAH-specific medications and subsequent transcatheter closure (ie, treat-and-repair strategy) on clinical outcomes.

METHODS

We enrolled 42 patients who were referred to 13 institutions for consideration of ASD closure with concomitant PAH and underwent the treat-and-repair strategy. The endpoint was cardiovascular death or hospitalisation due to heart failure or exacerbated PAH.

RESULTS

At baseline prior to PAH-specific medications, pulmonary to systemic blood flow ratio (Qp:Qs), pulmonary vascular resistance (PVR), and mean pulmonary artery pressure (PAP) were 1.9±0.8, 6.9±3.2 Wood units and 45±15 mm Hg. Qp:Qs was increased to 2.4±1.2, and PVR and mean PAP were decreased to 4.0±1.5 Wood units and 35±9 mm Hg at the time of transcatheter ASD closure after PAH-specific medications. Transcatheter ASD closure was performed without any complications. During a median follow-up period of 33 months (1-126 months) after transcatheter ASD closure, one older patient died and one patient was hospitalised due to heart failure, but the other patients survived with an improvement in WHO functional class. PAP was further decreased after transcatheter ASD closure.

CONCLUSIONS

The treat-and-repair strategy results in low complication and mortality rates with a reduction in PAP in selected patients with ASD complicated with PAH who have a favourable response of medical therapy.

Evolving Paradigms in the Treatment of Atrial Septal Defects With Pulmonary Arterial Hypertension

Atrial septal defects are one of the most frequently diagnosed congenital heart defects in adulthood. The presence of concurrent moderate or severe pulmonary arterial hypertension without Eisenmenger syndrome at the time of diagnosis can make for a challenging clinical scenario. There is continually evolving literature to determine the ideal approach to this subset of patients. Here we aim to review the clinical presentation, history, medical therapy, and closure options for atrial septal defects-pulmonary arterial hypertension with predominant left-to-right shunting, in the absence of Eisenmenger syndrome.

Combination of F-ASO and Targeted Medical Therapy in Patients With Secundum ASD and Severe PAH

OBJECTIVES

This study was conducted to investigate the combined use of fenestrated atrial septal occluder (F-ASO) and targeted medical therapy (TMT) in patients with secundum atrial septal defect (ASD) and severe pulmonary arterial hypertension (PAH).

BACKGROUND

Treatment of patients with ASD and severe PAH is still challenging.

METHODS

After ethical approval was obtained, 56 consecutive patients with ASD with severe PAH were included (7 men, 49 women; median age 50.5 years; mean ASD size 26.9 ± 4.6 mm). After 3 months of TMT, transcatheter closure was performed using F-ASO in patients with ratios of pulmonary to systemic blood flow ≥1.5. TMT was continued post-operatively together with 6 months of dual-antiplatelet therapy. The hemodynamic variables during baseline, TMT alone, and combined treatment with F-ASO were compared.

RESULTS

After only TMT, systolic pulmonary arterial pressure (-14.5 mm Hg; p < 0.001), pulmonary vascular resistance (-3.9 Wood units; p < 0.001), and exercise capacity (+72.0 m; p < 0.001) improved. Ratio of pulmonary to systemic blood flow increased by 0.9 (p < 0.001), with adverse cardiac remodeling (right ventricular dimension +3.5 mm; p < 0.001). Closure with F-ASO (median size 34.0 mm) led to further decrease in systolic pulmonary artery pressure (-6.0 mm Hg; p < 0.001). Follow-up (median duration 10 months) revealed further improvement in exercise capacity (+60.5 m; p < 0.001), with favorable cardiac remodeling (right ventricular dimension -9.9 mm; p < 0.001). In addition, all fenestrations were stable (p = 0.699), with negligible shunt (median ratio of pulmonary to systemic blood flow 1.1) and no complications. One year later, pulmonary artery pressure was normalized in 8 of 19 patients, and PAH recurred in 5 patients after discontinuation of TMT.

CONCLUSIONS

In patients with ASD and severe PAH, combination of F-ASO and TMT was a safe and effective procedure. Compared with TMT alone, the combined treatment further improved exercise capacity, with favorable cardiac remodeling.

"Treat and repair" strategy for shunt lesions: a critical review

The issue of operability in patients with shunt lesions and raised pulmonary vascular resistance is contentious. Several reports suggest that patients traditionally considered inoperable may be operated after treatment with targeted drug therapy for pulmonary arterial hypertension. We reviewed all the published literature of "treat and repair" approach to gain more insights into the utility of this approach. A critical appraisal of the published literature suggests that this approach is less established for patients with post tricuspid shunts, and for patients with pre-tricuspid shunts with modestly elevated indexed pulmonary vascular resistance (possibly greater than 11 WU.m²). Targeted drug therapy may be able to extend the therapeutic window in carefully selected patients, but its use as a routine in this setting seems unwarranted.

Transcatheter closure of atrial septal defect protects from pulmonary edema: septal occluder device gradually reduces LR shunt

A 56-year-old woman was diagnosed as atrial septal defect (ASD) with pulmonary hypertension; pulmonary blood flow/systemic blood flow (Qp/Qs) of 2.3, pulmonary artery pressure (PAP) of 71/23(39) mmHg and diastolic dysfunction of left ventricle. PAP was improved after medical therapy; therefore, transcatheter ASD closure was performed. Seven days later, left-sided heart failure occurred, however, the improvement of Qp/Qs (1.7) and PAP of 51/21(32) was confirmed. Diuretic therapy was introduced which led to further decrease of PAP 40/12(25) and Qp/Qs (1.1). Because of gradual decrease of Qp/Qs, this patient appeared to be protected from acute pulmonary edema.