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

Pulmonary arterial hypertension related to congenital heart disease with a left-to-right shunt: phenotypic spectrum and approach to management

Patients with pulmonary hypertension associated with a left-right shunt include a wide spectrum of pathophysiological substrates, ranging from those characterized by pulmonary over-circulation to those with advanced pulmonary vascular disease. The former group may benefit from shunt repair in carefully selected cases but, when advanced pulmonary vascular disease has developed, defect closure should be avoided, and pulmonary vasodilators may be used to improve effort tolerance and hemodynamics. There is a paucity of evidence, however, to support decision-making in the care of these patients. We discuss the principles of management in patients with pulmonary hypertension and a predominant left-right shunt. The recommendations and statements made in this paper are based on pathophysiological considerations and expert opinion.

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.

Pulmonary vasodilator therapies in pulmonary arterial hypertension associated with CHD: a systematic review and network meta-analysis

The optimal treatment strategy using pulmonary vasodilators in pulmonary arterial hypertension associated with CHD (PAH-CHD) remains controversial. We aimed to compare the efficacy and safety of pulmonary vasodilators in PAH-CHD. PubMed and EMBASE databases were searched through May 2022 and a network meta-analysis was conducted. The primary outcomes were mean difference of changes in 6-minute walk distance, NYHA functional class, and N-terminal pro-brain natriuretic peptide. The secondary outcomes included pulmonary vascular resistance, mean pulmonary arterial pressure, and resting oxygen saturation. We identified 14 studies, yielding 807 patients with PAH-CHD. Bosentan and sildenafil were associated with a significant increase in 6-minute walk distance from baseline compared with placebo (MD 48.92 m, 95% CI 0.32 to 97.55 and MD 59.70 m, 95% CI 0.88 to 118.53, respectively). Bosentan, sildenafil, and combination of bosentan and sildenafil were associated with significant improvement in NYHA functional class compared with placebo (MD -0.33, 95% CI -0.51 to -0.14, MD -0.58, 95% CI -0.75 to -0.22 and MD -0.62, 95% CI -0.92 to -0.31, respectively). Bosentan and sildenafil were also associated with significant improvements in secondary outcomes. These findings were largely confirmed in the subgroup analysis. Various adverse events were reported; however, serious adverse event rates were relatively low (4.8-8.7%), including right heart failure, acute kidney injury, respiratory failure, hypotension, and discontinuation of pulmonary vasodilators. In conclusion, bosentan and sildenafil were the most effective in improving prognostic risk factor such as 6-minute walk distance and NYHA class. Overall, pulmonary vasodilators were well tolerated in PAH-CHD.

Hemodynamics of vascular shunts: trends, challenges, and prospects

Vascular bypass surgery takes a significant place in the treatment of vascular disease. According to various assessments, this type of surgery is associated with almost 20 % of all vascular surgery episodes (up to 23 % according to the Federal Neurosurgical Center of Novosibirsk). Even though the problem of using of vascular grafts is obvious and natural, many problems associated with them are not still elucidated. From the mechanics' point of view, a vascular bypass is a converging or diverging tee, and the functioning of such structures still does not have strict mathematical formulations and proofs in the general case, which forces many researchers to solve specific engineering problems associated with shunting. Mathematical modeling, which is the gold standard for virtual simulations of industrial and medical problems, faces great difficulties and limitations in solving problems for vascular bypasses. Complications in the treatment of the vascular disease may follow the difficulties in mathematical modeling, and the price can be a cardiac arrest or a stroke. This work is devoted to the main aspects of the medical application of vascular bypasses and their functioning as a mechanical system, as well the mathematical aspects of their possible setup.

Treatment of left main coronary artery compression in the setting of unpalliated congenital heart disease: a case series

Background

Left main coronary artery compression syndrome (LMCS) is a well-characterized phenomenon resulting from compression of the left main coronary artery (LMCA) between the aorta and an enlarged pulmonary arterial trunk. The development of LMCS is usually described in the context of severe pulmonary arterial hypertension. Cases of LMCS, in the context of unpalliated congenital heart disease (CHD), are complex clinical scenarios that challenge traditional treatment paradigms.

Case summary

Here, we discuss two thought-provoking patients with unpalliated CHD complicated by severe pulmonary hypertension (PH). Both patients developed LMCS, one with severe non-ST elevation myocardial infarction and the other with refractory angina. Their pulmonary vascular resistance was severely elevated despite pulmonary vasodilator therapy, and concomitant surgical correction of their CHD in addition to bypass grafting was deemed high risk. They underwent successful percutaneous coronary intervention (PCI) of the LMCA with drug-eluting stents.

Discussion

Pulmonary hypertension can develop in the setting of long-standing unpalliated CHD. Surgical correction of congenital heart defects may be performed in select patients with systemic-to-pulmonary shunts, contingent on the status of PH severity. Pulmonary vasodilator therapy modulates haemodynamics to ensure surgical correction without risk of cardiopulmonary demise-termed the 'treat and repair' strategy. LMCS, an increasingly recognized phenomenon in patients with long-standing PH, is a notable complicating factor in the 'treat and repair' strategy. We introduce the concept that PCI of the LMCA may bridge patients to corrective surgery for CHD by allowing time for optimization of their pulmonary vasodilator therapy.

The Treatment Strategy for the Atrial Septal Defect in the Presence of Severe Pulmonary Hypertension

Atrial septal defect is one of the most common congenital heart diseases in adults. The defect often leads to volume overload in the right heart coupled with the potential risk of right heart failure and pulmonary arterial hypertension. These conditions lead to worsening in quality of life, decrease in physical capacity, and even to fatal outcomes. The main strategy for treatment of atrial septal defect is a transcatheter or surgical closure of the defect, but in patients with severe pulmonary arterial hypertension, it is recommended to manage pulmonary arterial hypertension and after that treat the defect invasively. This strategy is called “treat and repair” strategy. We present an illustrative case report of management and treatment of atrial septal defect, complicated with severe pulmonary arterial hypertension. In this case, surgical closure of the defect was contraindicated because of the high pulmonary vascular resistance. Therefore, the “treat and repair” strategy was approached. After specific medical treatment of pulmonary arterial hypertension, surgical closure of the defect was chosen and proven successful.

The use of pulmonary arterial hypertension therapies in Eisenmenger syndrome

INTRODUCTION

For many years, treatment options for patients with Eisenmenger physiology had been restricted to conservative measures to alleviate multi-system complications. The use of pulmonary arterial hypertension (PAH)-targeted therapies in patients with Eisenmenger syndrome (ES) changed the course of the disease, since they substantially improved clinical outcomes and increased survival.

AREAS COVERED

In this review, we primarily focus on the use of PAH pharmacotherapies in ES. A literature search was carried out in PubMed, Scopus and Cochrane Database up to May 2021. We thoroughly discuss current evidence about mechanisms of action, safety, and efficacy of these agents and present challenges and gaps in literature regarding the recommended treatment approach.

EXPERT OPINION

Unlike other forms of PAH, we usually treat patients with ES more conservatively as we lack evidence that aggressive management is safe and effective in this complex population. Several issues on the time of initiation of PAH-targeted therapies, choice between monotherapy vs. upfront combination therapy, and time of escalation still remain challenging and require further investigation. Therapeutic management should be guided by patients' individual evaluation based on available prognostic markers. More well-designed trials are warranted to assess the benefits of new PAH-targeted agents and combination therapies.

Temperate approach to ASD closure in pulmonary arterial hypertension: the fenestrated patch technique

The most common CHD in the adult patient population is an atrial septal defect due to its asymptomatic nature in early life. However, when diagnosis and treatment are delayed, pulmonary arterial hypertension may develop as a long-term complication, sometimes before adulthood. The presence of PAH adversely affects the results of surgical treatment and may even eliminate the feasibility of surgery in some patients. In such patients who have high pulmonary artery pressure and pulmonary vascular resistance at the margin of inoperability, the response to the acute vasoreactivity test determines the treatment modality.In our retrospective study, a total of 906 patients who underwent ASD closure between January, 2011 and November, 2020, seven of which had undergone the fenestrated patch procedure after they were identified to have high PAP, but positive AVT test response were included. Short-term follow-up of patients with fenestrated ASD patches revealed decreased pulmonary pressure, regression in NYHA classification, and improvement in symptoms.The fenestrated patch technique should be kept in mind as an option to expand the surgical spectrum in the treatment of patients with high pulmonary pressures, where complete closure is risky. It appears that the fenestrated patch technique is a safe approach in the management of pulmonary hypertension in patients with ASD who have pulmonary hypertension, according to short- and midterm follow-up findings.

Atrial septal defect in adulthood: a new paradigm for congenital heart disease

Atrial septal defects (ASDs) represent the most common congenital heart defect diagnosed in adulthood. Although considered a simple defect, challenges in optimal diagnostic and treatment options still exist due to great heterogeneity in terms of anatomy and time-related complications primarily arrhythmias, thromboembolism, right heart failure and, in a subset of patients, pulmonary arterial hypertension (PAH). Atrial septal defects call for tertiary expertise where all options may be considered, namely catheter vs. surgical closure, consideration of pre-closure ablation for patients with atrial tachycardia and suitability for closure or/and targeted therapy for patients with PAH. This review serves to update the clinician on the latest evidence, the nuances of optimal diagnostics, treatment options, and long-term follow-up care for patients with an ASD.

A case of a middle-aged patient with a ventricular septal defect complicated by severe pulmonary hypertension-stepwise surgical repair with pulmonary vasodilators

We report a case of ventricular septal defect (VSD) in which we attempted to treat pulmonary arterial hypertension (PAH) with the goal of VSD closure in an adult with suspected Eisenmenger syndrome in childhood. Four years previously (age 41 years), she was referred to our department due to repeated hemoptysis requiring further treatment of PAH. We started combination therapy with several pulmonary vasodilators. Two years later, her pulmonary vascular resistance (PVR) was improved but still not at the level where VSD closure was possible. To control the increased PA flow resulting from intensive PAH treatment and to reduce the risk of hemoptysis, we performed pulmonary artery banding (PAB). As the risk of hemoptysis decreased, a prostacyclin analog was introduced, and the dose was increased. More than 1 year after PAB, active vasoactivity testing became positive, suggesting that the pulmonary vascular lesion was now "reversible". We performed VSD closure and atrial septal defect creation even though her PVR was still high. After the operation, her exercise capacity was remarkably improved. We suggest that stepwise surgical repair with pulmonary vasodilators is an important treatment option for select patients with VSD with severe PAH. <Learning objective: Advances in pulmonary arterial hypertension (PAH) treatment have led to the use of a "treat-and-repair" strategy to close the intracardiac shunt after PAH treatment in select patients with adult congenital heart disease. In our case, ventricular septal defect (VSD) closure was achieved with stepwise surgical repair and a combination of pulmonary vasodilators, even though long-standing severe PAH with persistent hemoptysis remained. Even after a long period of exposure to high blood flow, this strategy may reduce pulmonary vascular resistance and permit eventual closure of the VSD.>.

Preventing disease progression in Eisenmenger syndrome

Introduction: Eisenmenger syndrome describes a condition in which a congenital heart defect has caused severe pulmonary vascular disease, resulting in reversed (right-left) or bidirectional shunting and chronic cyanosis.Areas covered: In this paper, the progression of congenital heart defects to Eisenmenger syndrome, including early screening, diagnosis and operability are covered. The mechanisms of disease progression in Eisenmenger syndrome and management strategies to combat this, including the role of pulmonary arterial hypertension therapies, are also discussed.Expert opinion/commentary: Patients with congenital heart disease (CHD) are at increased risk of developing pulmonary arterial hypertension with Eisenmenger syndrome being its extreme manifestation. All CHD patients should be regularly assessed for pulmonary hypertension. Once Eisenmenger syndrome develops, shunt closure should be avoided. The clinical manifestations of Eisenmenger syndrome are driven by the systemic effects of the pulmonary hypertension, congenital defect and long-standing cyanosis. Expert care is essential for avoiding pitfalls and preventing disease progression in this severe chronic condition, which is associated with significant morbidity and mortality. Pulmonary arterial hypertension therapies have been used alongside supportive care to improve the quality of life, exercise tolerance and the outcome of these patients, although the optimal timing for their introduction and escalation remains uncertain.

Congenital Heart Disease-Associated Pulmonary Hypertension

Presently, with increasing survival of patients with congenital heart disease (CHD), pulmonary arterial hypertension (PAH) associated with CHD is commonly encountered in children and adults. This increased prevalence is seen despite significant advances in early diagnosis and surgical correction of patients with structural CHD. PAH is the cause of significant morbidity and mortality in these patients and comes in many forms. With the increased availability of targeted therapies for PAH, there is hope for improved hemodynamics, exercise capacity, quality of life, and possibly survival for these patients. There may also be opportunities for combined medical and interventional/surgical approaches for some.