Interventional treatment of atrial septal defects in the elderly
Atrial septal defects (ASD) are one of the common congenital heart diseases, accounting for about 10% of congenital heart diseases, and are classified as secondary foramen type, primary foramen type and venous sinus type. Surgical closure of ASDs is the standard approach, especially for primary foramen ovale ASDs [1]. In the last 40 years, transcatheter interventional closure has become a safe and effective means of treating secondary foramen ovale ASD [2]. Numerous clinical studies have shown good intermediate and long-term outcomes for interventional treatment of ASD in children and adults [3] [4]. As most congenital heart diseases have been treated in adolescence and early adulthood, untreated congenital heart diseases in old age (R60 years) are dominated by ASD. However, elderly patients with ASD have special challenges for transcatheter interventional closure of ASD in old age due to the complexity of their condition.
I. Clinical characteristics of ASD in the elderly
ASD in the elderly mostly exists due to the following two conditions: pre-existing ASD that has been detected but not treated; newly detected ASD. in adolescence, ASD mostly has no obvious clinical manifestations, and easy fatigue, palpitations and exertional dyspnea gradually appear with the development of the disease. These symptoms worsen with age and are associated with right heart remodeling and hemodynamic deterioration, partly due to left ventricular diastolic dysfunction. Long-term left-to-right shunts increase the right heart load, leading to right heart failure and pulmonary hypertension, while right atrial enlargement can cause atrial arrhythmias such as atrial fibrillation, and is a contraindication to closing ASD if further severe pulmonary hypertension and Eisenmanger syndrome occur.In addition to ASD size, age and female are also risk factors associated with pulmonary hypertension in patients with ASD, and moderate to severe pulmonary hypertension is significantly more common in older patients [5]. Older patients with ASD have significantly different pathophysiological characteristics compared to younger patients. In elderly patients, due to aging, combined atherosclerosis, hypertension, and diabetes mellitus, left ventricular diastolic compliance is reduced and filling pressures are elevated, which may both aggravate left-to-right shunts and may lead to worsening clinical conditions after ASD closure, because the presence of ASD reduces left ventricular filling and this effect disappears after closure, causing a sudden increase in left ventricular filling pressures and left heart failure and pulmonary edema [6].
II. Indications for interventional therapy
The 2008 ACC/AHA practice guideline for adult congenital heart disease requires that ASDs should be closed as early as possible, with no upper age limit, and is a Class IA recommendation for patients with an indication [7]. Although closure of ASDs can be beneficial at any age, the best benefit is in patients with little functional impairment and low elevation of pulmonary artery pressure. Considering that ASDs cause a continuous progressive deterioration of cardiac structure and function with age, early closure is advocated, even in elderly patients [8]. Early closure of ASDs can eliminate complications such as pulmonary hypertension, atrial arrhythmias, right heart failure and thromboembolism that occur with age.
The indications and contraindications for interventional treatment of ASD are as follows
Indications
ASD with a diameter <36 mm secondary to foramen ovale.
Evidence of increased right heart volume load such as right atrial and right ventricular enlargement (cardiac ultrasound, MRI, CT) and pulmonary hypertension or Qp/Qs >1.5 on cardiac catheterization.
The defect is >5 mm from the coronary sinus, mitral valve, vena cava and pulmonary veins.
Other congenital heart disease for which intervention is feasible
Evidence of paradoxical embolism, regardless of defect size and presence of symptoms
Contraindications
Severe pulmonary hypertension with Qp/Qs <0.7 and pulmonary vascular resistance >7woods
no significant improvement in left heart system hemodynamic parameters after rigorous preoperative management
Primary orifice type and venous sinus type ASD.
Combined with other structural heart disease not amenable to intervention
Intra-cardiac thrombus.
III. Efficacy of interventional treatment
To date, there are few and controversial data on interventional treatment of ASD in the elderly, concerning the long-term outcomes such as whether the right heart is retracted and the improvement of symptoms. Early data suggest that surgical closure of middle-aged and elderly ASDs may be accompanied by heart failure, stroke, and atrial arrhythmias, and thus the need for closure in asymptomatic adult ASD patients is controversial [10]. The key is that the relevant research data do not meet the requirements of modern evidence-based medicine, and this problem still exists so far. As clinical research and practice progress, more data suggest that ASD in middle-aged and older adults should be closed promptly, regardless of the presence or absence of symptoms. The natural course of untreated ASD often shortens life expectancy while symptoms progressively progress, with 30% of patients developing exertional dyspnea by age 30 and 75% by age 50 [9]. In younger patients, closure of ASD leads to improved right heart remodeling, decreased pulmonary artery pressure, and reduced or even disappeared clinical symptoms, and these effects are immediate, but right ventricular retraction is later in older patients, mostly after 6 weeks postoperatively, showing differences in the time effect between younger and older patients [11].Swan et al [12] retrospectively analyzed the clinical data of early interventional closure treatment of ASD and compared interventional outcomes in older patients and those <60 years of age. Older patients, who accounted for 27% of all ASD interventions, had higher baseline right ventricular systolic pressure and worse NYHA classification. There was no difference in ASD size or operative time between the two groups. Sealing treatment effectively reduced right ventricular systolic pressure and right ventricular size to a similar extent in both groups, but right ventricular systolic pressure remained higher in the elderly group than in the <60-year-old group after the procedure. Despite the increased comorbidities such as coronary artery disease and hypertension in elderly patients, there was no difference in procedure-related complications between the two groups. Preliminary data suggest that ASD interventional occlusion in elderly patients is safe and effective. In a larger study, 96 elderly patients with ASD were treated with interventional occlusion and follow-up showed a reduction in symptoms (improvement in NYHA classification), improvement in exercise capacity (1-2 ml/kg.min increase in peak oxygen consumption on cardiopulmonary exercise test), and more pronounced improvement in patients with Qp/Qs >2, along with a significant reduction in the dilated right ventricle [13].Khan et al [10] successfully occluded 23 elderly patients with ASD and followed up for one year, with improved NYHA classification, 94 m longer 6-minute walking distance, and significantly better mental and physical scores on the Quality of Life Questionnaire. Echocardiography suggested a smaller right ventricular diameter, increased left ventricular diameter, and improved left ventricular EF; the improvement in left ventricular function resulted from increased left ventricular filling and preceded right ventricular narrowing, and thus may not be dependent on the effects of right ventricular remodeling.Altindag et al [14] observed the results of interventions in patients with ASD over 40 years of age (mean age 58 ± 13 years), and regardless of preoperative age, almost all patients had right ventricular shrinkage, improved NYHA classification, and decreased pulmonary artery pressure, suggesting that age is not a major factor in determining outcome. The above-mentioned studies show that elderly patients with ASD can benefit from interventional therapy, accompanied by improvements in cardiac structure and function and an improved quality of life.
IV. Interventional therapy versus surgical procedures
Surgical closure of ASD has been experienced for decades, and numerous studies have compared the advantages and disadvantages of the two treatments. du et al [15] compared the multicenter results of surgical and interventional closure of ASD, and there was no difference in the success rate between the two with no deaths, complications of interventional treatment were 7.2% compared to 24% for surgical procedures, and the length of stay was significantly longer for surgical procedures than for interventional treatments. In an earlier study, complications of surgery in patients over 60 years of age were 24% and surgical mortality was 6% [16]. Due to the disadvantages of surgery with associated increased complications and prolonged hospital stay, with the improvement and refinement of interventional devices and advances in interventional techniques, interventional therapy has become the standard of care for secondary foramen ovale ASD, especially in elderly patients with simple ASD.
Compared with surgery, the superiority of interventional treatment for elderly ASD is more obvious [17]: 1. Faster improvement in NYHA classification and dyspnea score, which may be related to faster recovery after interventional procedures and complications of surgical cardiac incision and cardiopulmonary bypass 2. Improvement in myocardial work indices in the right and left ventricles, especially in the right ventricle, while little improvement after surgery, stemming from the impairment of right ventricular function by cardiopulmonary bypass 3. Other Benefits, such as social benefits from shorter hospitalization and recovery time, reduced psychological burden of patients and families, etc.
V. Problems faced
At present, it is advocated to close ASD in the elderly as early as possible, and to use interventional therapy in suitable patients as much as possible. However, due to the complexity of the physiological condition of elderly patients, there are still some problems to be solved in clinical practice. Interventional therapy blocks the left-to-right shunt, which may lead to elevated left atrial pressure, left heart insufficiency and even pulmonary edema in some elderly patients due to the underlying left ventricular hypocompliance. For patients with preoperative left atrial pressure over 15 mmHg, caution should be exercised, and trial blocking can be performed first to observe the change of pulmonary artery wedge pressure (PCWP), and if the PCWP rises over 5 mmHg, appropriate diuretic and vasodilatory anti-cardiac failure measures should be given before blocking, or blockers with holes can be used for treatment [17][18]. The key lies in the preoperative development of a reasonable treatment plan, careful intraoperative management and close observation. Prolonged left-to-right shunting at the atrial level leads to right atrial remodeling, which can result in atrial arrhythmias, and aging accelerates this process. Whether intervention can reduce pre-existing arrhythmias is unclear, but notably, Jategaonkar et al [13] found that 20% (16/88 cases) of elderly patients with ASD had new onset of atrial fibrillation within 3 months after intervention, so the increase in postoperative atrial arrhythmias is worthy of clinical attention. Elderly patients have many comorbidities, such as combined coronary artery disease and valvular disease, and the specific treatment plan should be determined by the type of lesion and the patient’s wishes. Finally, there are no multicenter randomized controlled studies comparing transcatheter interventions for ASD with drug therapy alone, mainly based on ethical issues and the benefits already obtained from interventions, but we still expect evidence-based medical evidence to further elucidate the benefits of interventions for ASD in the elderly.
VI. Summary
Transcatheter intervention for secondary foramen ovale ASD has become the standard of care and is a safe and effective treatment even in elderly patients over 60 years of age, reversing right ventricular remodeling, improving cardiac function, and enhancing quality of life. Due to the unique physiological and clinical complexity of elderly patients, they should be treated differently in clinical practice, and reasonable treatment plans should be developed to reduce the occurrence of related complications.