Atrial septostomy for pulmonary arterial hypertension

Timely PAH Identification in Adults With Repaired Congenital Heart Disease? The ACHD-QuERI Registry Insights

Background

The Quality Enhancement Research Initiative (QuERI) in adults with congenital heart disease (ACHD) was developed to improve detection of pulmonary arterial hypertension (PAH) after repair of systemic-to-pulmonary arterial shunt lesions.

Objectives

This study sought to standardize use of accepted criteria for PAH diagnosis and evaluate utility in at-risk patients with ACHD.

Methods

Patients ≥18 years of age with ACHD repaired ≥1 year before enrollment and with additional risk factors for developing PAH were eligible. History, physical examination, electrocardiogram, transthoracic echocardiogram, World Health Organization functional class, and 6-minute walk distance were evaluated at baseline and yearly for 3 years. Pop-up reminders of patient-specific evidence-based recommendations for PAH detection appeared during data entry.

Results

Among 217 eligible patients, mean age (enrollment) was 44.0 ± 15.9 years, 72.3% were women, and 82.0% were World Health Organization functional class I. Electrocardiogram was performed in >80% and TTE in >70% of patients annually; capture of required transthoracic echocardiography (TTE) measures and alignment between study- and core-center interpretation improved over time, with more frequent assessment of pulmonary arterial flow acceleration time and documentation of right ventricular outflow tract Doppler notching. Approximately 40% of patients had ≥2 high-risk features for PAH on TTE, but only 7% (6/82) underwent right heart catheterization (RHC). Using current definitions, 2 patients were confirmed by RHC to have a diagnosis of PAH (maximum follow-up 3 years).

Conclusions

A structured protocol may improve screening for patients with repaired ACHD at risk of developing PAH. RHC may be underutilized in patients with ACHD with TTE findings suggestive of PAH. (Adult Congenital Heart Disease Registry [QuERI]; NCT01659411).

Is combined use of radiofrequency ablation and balloon dilation the future of interatrial communications?

INTRODUCTION

Personalized and stable interatrial communication is an important palliative therapy for patients with heart failure. However, this remains a technically challenging task.

AREAS COVERED

In the past decades, substantial advancements in atrial septostomy for the creation of controllable and durable interatrial communication have been made, and numerous novel devices and techniques are in various stages of development. In this review, we discuss the evolving indications for atrial septostomy, current approaches with or without device implantation, and indicators for optimal interatrial communication. The combined use of radiofrequency ablation and balloon dilation (CURB) is an individualized management approach based on underlying hemodynamics, which demonstrates unique advantages in creating a sufficient interatrial communication with satisfactory stability. The advantages and disadvantages of this implant-free procedure are analyzed and its clinical prospects are assessed.

EXPERT OPINION

With ready availability, high safety, and efficacy, CURB is a promising procedure for creating personalized and stable interatrial communication without device implantation. Further research is required to simplify the procedure, screen optimal reference parameters for personalized therapy, and evaluate the long-term outcome in a large population of patients.

First in-human modified atrial septostomy combining radiofrequency ablation and balloon dilation

OBJECTIVE

Preclinical research suggests that the combined use of radiofrequency ablation and balloon dilation (CURB) could create stable interatrial communications without device implantation. This study examined the first in-human use of CURB for modified atrial septostomy in patients with severe pulmonary arterial hypertension (PAH).

METHODS

Between July 2018 and October 2021, CURB was performed in 19 patients with severe PAH (age: 31.5±9.1 years; mean pulmonary artery pressure: 73 mm Hg (IQR: 66-92); pulmonary vascular resistance: 18.7 Wood units (IQR: 17.8-23.3)). Under guidance of intracardiac echocardiography and three-dimensional location system, (1) fossae ovalis was reconstructed and ablated point-by-point with radiofrequency; (2) then graded balloon dilation was performed after transseptal puncture and the optimal size was determined according to the level of arterial oxygen saturation (SatO₂); (3) radiofrequency ablation was repeated around the rims of the created fenestration. The interatrial fenestrations were followed-up serially.

RESULTS

After CURB, the immediate fenestration size was 4.4 mm (IQR: 4.1-5.1) with intracardiac echocardiography, systolic aortic pressure increased by 10.2±6.9 mm Hg, cardiac index increased by 0.7±0.3 L/min/m² and room-air resting SatO2 decreased by 6.2±1.9% (p<0.001). One patient experienced increased pericardiac effusion postoperatively; the others had no complications. On follow-up (median: 15.5 months), all interatrial communications were patent with stable size (intraclass correlation coefficient=0.96, 95%CI:0.89 to 0.99). The WHO functional class increased by 1 (IQR: 1-2) (p<0.001) with improvement of exercise capacity (+159.5 m, P<0.001).

CONCLUSION

The interatrial communications created with CURB in patients with severe PAH were stable and the mid-term outcomes were satisfactory.

TRIAL REGISTRATION NUMBER

NCT03554330.

Study of the effect of Occlutech Atrial Flow Regulator on symptoms, hemodynamics, and echocardiographic parameters in advanced pulmonary arterial hypertension

Optimal sized balloon atrial septostomy improves hemodynamics in advanced pulmonary arterial hypertension. Occlutech Atrial Flow Regulator is designed to provide an atrial septal fenestration diameter titrated according to the age and right atrial pressures. This observational study analyzed symptoms, exercise distance, oxygen saturations, hemodynamics and echocardiographic parameters after Atrial Flow Regulator implantation in patients with syncope or right-heart failure. Patients with high-risk predictors of mortality during septostomy were scrutinized. Thirty-nine patients (9 children) with syncope (34/39) or right-heart failure (27/39) underwent Atrial Flow Regulator implantation without procedural complications. Six-minute walk distance increased from 310 ± 158.2 to 376.4 ± 182.6 m, none developed syncope. Oxygen saturations reduced from 96.4 ± 6.4% to 92 ± 4.9% at rest and further to 80.3 ± 5.9% on exercise. Right atrial pressures reduced from 9.4 ± 5 (2-27) mmHg to 6.9 ± 2.6 (1-12) mmHg, while cardiac index increased from 2.4 ± 0.8 (0.98-4.3) to 3 ± 1 (1.1-5.3) L/min/m² and systemic oxygen transport increased from 546.1 ± 157.9 (256.2-910.5) to 637.2 ± 191.1 (301.3-1020.2) ml/min. Echocardiographic improvement included significant reduction of pericardial effusion and inferior caval congestion at a median follow-up of 37 months. Overall survival improved except two early and one late deaths in high-risk patients. Five of seven patients with advanced disease and key hemodynamic predictors of mortality survived. Acute hemodynamic benefits in pulmonary arterial hypertension after Atrial Flow Regulator were improved cardiac output, systemic oxygen transport, and reduced right atrial pressures. Improvement of symptoms especially syncope, exercise duration, and right ventricular systolic function as well as device patency were sustained on mid-term follow-up. Implantation was safe in all including young children without procedural complications. Mortality was noted only in patients who had high-risk predictors and patients at advanced stage of the disease.

Graded balloon atrial septostomy for palliation of congenital pulmonary hypertension in a dog: A case report

CASE DESCRIPTION

A 6-month-old intact female Maltese dog was presented for acute onset of syncope.

CLINICAL FINDINGS

The dog was presented for collapse upon excitement and exercise. It collapsed at discharge and suffered cardiopulmonary arrest. Echocardiography after resuscitation indicated severe pulmonary hypertension without evidence of intracardiac or extracardiac shunting. A presumptive diagnosis of congenital pulmonary hypertension was made.

TREATMENT AND OUTCOME

Initial treatment with sildenafil was effective at relieving syncope, but the extent of pulmonary hypertension as determined by serial echocardiography was unchanged. Graded balloon atrial septostomy was performed as a palliative procedure. Follow-up echocardiography identified a patent interatrial communication with bidirectional shunting. The dog remained asymptomatic 18 months after treatment.

CLINICAL RELEVANCE

To the best of our knowledge, this study is the first report in the veterinary literature of graded balloon atrial septostomy performed for therapeutic purposes. Further studies are required to determine if this palliative procedure is a beneficial treatment option for dogs with congenital or severe refractory pulmonary hypertension.

Transvenous implantation of the Occlutech Atrial Flow Regulator: Preliminary results from swine models

AIMS

To evaluate in domestic pigs the histopathological processes after implanting the Occlutech Atrial Flow Regulator (AFR).

METHODS AND RESULTS

Eleven pigs were chosen and had successful implantation of the AFR. Five pigs were sacrificed at 28 days, and 5 pigs at 90 days. One pig was sacrificed at day 3 after device embolization. Each pig had echocardiography performed at 3 weeks to check patency. Post mortem evaluation included Gross evaluation, radiographic evaluation, histology, and electron microscopy. Nine of the 10 devices implanted remained patent at time of autopsy with no thrombus and minimal inflammation. One device placed in the PFO closed by day 28 and the other embolized on day 3.

CONCLUSION

The Occlutech AFR has shown to be safe and easy to implant with good results [Krizanic et al. J Invasive Cardiol. 2010;22(4):182.]. This study has further shown that histologically the device does not cause any end organ damage, causes minimal inflammation, with almost no thrombus formation and can remain patent and secure in the atrial septum.

Use of Balloon Atrial Septostomy in Patients With Advanced Pulmonary Arterial Hypertension: A Systematic Review and Meta-Analysis

BACKGROUND

Despite the use and purported benefits of balloon atrial septostomy (BAS), its safety, efficacy, and therapeutic role in the setting of advanced pulmonary arterial hypertension (PAH) are not well defined.

OBJECTIVE

The goal of this study was to conduct a systematic review and meta-analysis to better determine the evidence supporting the use of BAS in PAH.

METHODS

MEDLINE, Scopus, Cochrane Library, and Clinicaltrials.gov were searched from inception through May 2018 for original studies reporting outcomes with PAH prior to and following BAS. Studies comparing BAS vs other septostomy procedures were excluded. Weighted mean differences and 95% CIs were pooled by using a random effects model.

RESULTS

Sixteen studies comprising 204 patients (mean age, 35.8 years; 73.1% women) were included. Meta-analysis revealed significant reductions in right atrial pressure (-2.77 mm Hg [95% CI, -3.50, -2.04]; P < .001) and increases in cardiac index (0.62 L/min/m² [95% CI, 0.48, 0.75]; P < .001) and left atrial pressure (1.86 mm Hg [95% CI, 1.24, 2.49]; P < .001) following BAS, along with a significant reduction in arterial oxygen saturation (-8.45% [95% CI, -9.93, -6.97]; P < .001). The pooled incidence of procedure-related (48 h), short-term (≤ 30 day), and long-term (> 30 days up to a mean follow-up of 46.5 months) mortality was 4.8% (95% CI, 1.7%, 9.0%), 14.6% (95% CI, 8.6%, 21.5%), and 37.7% (95% CI, 27.9%, 47.9%), respectively.

CONCLUSIONS

The present analysis suggests that BAS is relatively safe in advanced PAH, with beneficial hemodynamic effects. The relatively high postprocedural and short-term survival with less impressive long-term survival suggest a bridging role for BAS; its contribution to this change needs to be verified by using a comparator group.

Interventional Therapies in Pulmonary Hypertension

Despite advances in drug therapy, pulmonary hypertension-particularly arterial hypertension (PAH)-remains a fatal disease. Untreatable right heart failure (RHF) from PAH eventually ensues and remains a significant cause of death in these patients. Lowering pulmonary input impedance with different PAH-specific drugs is the obvious therapeutic target in RHF due to chronically increased afterload. However, potential clinical gain can also be expected from attempts to unload the right heart and increase systemic output. Atrial septostomy, Potts anastomosis, and pulmonary artery denervation are interventional procedures serving this purpose. Percutaneous balloon pulmonary angioplasty, another interventional therapy, has re-emerged in the last few years as a clear alternative for the management of patients with distal, inoperable, chronic thromboembolic pulmonary hypertension. The current review discusses the physiological background, experimental evidence, and potential clinical and hemodynamic benefits of all these interventional therapies regarding their use in the setting of RHF due to severe pulmonary hypertension.

Tailored circulatory intervention in adults with pulmonary hypertension due to congenital heart disease

BACKGROUND

Adults with pulmonary hypertension associated with congenital heart disease (PH-CHD) often have residual shunts. Invasive interventions aim to optimise pulmonary flow and prevent right ventricular failure. However, eligibility for procedures strongly depends on the adaptation potential of the pulmonary vasculature and right ventricle to resultant circulatory changes. Current guidelines are not sufficiently applicable to individual patients, who exhibit great diversity and complexity in cardiac anomalies.

METHODS AND RESULTS

We present four complex adult PH-CHD patients with impaired pulmonary flow, including detailed graphics of the cardiopulmonary circulation. All these patients had an ambiguous indication for shunt intervention. Our local multidisciplinary Grown-Ups with Congenital Heart Disease team reached consensus regarding a patient-tailored invasive treatment strategy, adjacent to relevant guidelines. Interventions improved pulmonary haemodynamics and short-term clinical functioning in all cases.

CONCLUSIONS

Individual evaluation of disease characteristics is mandatory for tailored interventional treatment in PH-CHD patients, adjacent to relevant guidelines. Both strict registration of cases and multidisciplinary and multicentre collaboration are essential in the quest for optimal therapy in this patient population.

Stepwise Approach Using Combined Management in Patients with Congenital Heart Disease and Borderline Pulmonary Vascular Disease

Background and Objectives

Despite remarkable advances in pediatric cardiology, pulmonary arterial hypertension associated with congenital heart disease remains a major problem. In the past decade new vasodilators have been introduced and appear to be effective in reducing pulmonary vascular resistance (PVR).

Subjects and Methods

From 2000 to 2011, we retrospectively reviewed the records of 22 patients who had congenital septal defects and borderline pulmonary vascular disease (PVD). The PVR in these patients was from 6 to 16 wood units · m², and/or the systolic pulmonary arterial pressure was more than 2/3 of the systemic arterial pressure.

Results

The median age was 16 years (range, 9 months-46 years). The median duration of follow-up was 7.4 years (range, 1.4-11.7 years). According to hemodynamic data and clinical symptoms, the initial management comprised targeted medical therapy in four (18%), complete closure in four (18%), and partial closure in 14 patients (63.6%). In the four patients who had a high PVR and negative vasoreactivity, the PVR decreased and vasoreactivity increased after targeted medical therapy; three of these patients underwent cardiac surgery later. Finally, 11 (50%) received targeted medical therapy and 21 patients (95.4%) underwent cardiac surgery. Complete closure resulted in six patients and partial closure in 17 patients. Mortality was observed in two patients. The other 19 patients (91%) had New York Heart Association functional class I.

Conclusion

Targeted medical therapy may be effective in reducing PVR in patients with congenital heart disease and borderline PVD. A stepwise approach may help to achieve improved outcomes in these patients.

Interventional and surgical therapeutic strategies for pulmonary arterial hypertension: Beyond palliative treatments

Despite significant advances in pharmacological treatments, pulmonary arterial hypertension remains an incurable disease with an unreasonably high morbidity and mortality. Although specific pharmacotherapies have shifted the survival curves of patients and improved exercise endurance as well as quality of life, it is also true that these pharmacological interventions are not always accessible (particularly in developing countries) and, perhaps most importantly, not all patients respond similarly to these drugs. Furthermore, many patients will continue to deteriorate and will eventually require an additional, non-pharmacological, intervention. In this review we analyze the role of atrial septostomy and Potts anastomosis in the management of patients with pulmonary arterial hypertension, we summarize the current worldwide clinical experience (case reports and case series), and discuss why these interventional/surgical strategies might have a therapeutic role beyond that of a "bridge" to transplantation.

Balloon dilation atrial septostomy for advanced pulmonary hypertension in patients on prostanoid therapy

BACKGROUND

Prostanoid therapy improves quality of life and may increase survival in patients with advanced pulmonary hypertension (PH). Balloon dilated atrial septostomy (BDAS) can palliate or bridge to transplantation for patients resistant to medical therapy. The safety and efficacy of BDAS in the prostanoid era has not previously been reported.

METHODS

All patients had progressive symptoms despite prostanoid therapy at the time of their first BDAS. Sixteen patients who underwent a total of 23 septostomies between 2004 and 2014 were included in this retrospective case series.

RESULTS

Patients were aged 47.6 years ± 11.3 with 12/16 women. Etiologies included idiopathic (7), methamphetamine (6), scleroderma (1), and anorexigen (2). One patient died within 24 hr post-procedure. Thirty-day and 1-year survival were 75% and 64%, respectively. Six of the septostomies were revisions, including two which were ultimately stented. Three subjects were successfully bridged to transplant. Pulmonary capillary wedge pressure (PCWP) increased from a mean of 13 to 17 mm Hg, cardiac index increased from 2.1 to 2.4 L/min/m(2) , and arterial saturation decreased from 90.7 ± 4.3 to 82.5 ± 5.6%. All non-survivors at 30 days were male and had higher baseline serum creatinine, mean RAP, right ventricular end diastolic pressure (RVEDP), and left ventricle (LV) filling pressures, and lower right ventricle (RV) ejection fraction. Mortality was associated with unchanged post-septostomy cardiac output despite an increase in left ventricular end diastolic pressure (LVEDP).

CONCLUSIONS

BDAS may be an alternate therapy for select PH patients who have symptomatic progression despite prostanoid therapy. Survival is comparable to prior reports of BDAS in the pre-prostanoid era.

Impact of differential right-to-left shunting on systemic perfusion in pulmonary arterial hypertension

OBJECTIVES

This study aimed at identifying the ideal right-to-left shunt-fraction to improve cardiac output (CO) and systemic perfusion in pulmonary arterial hypertension (PHT).

BACKGROUND

Atrial septostomy (AS) has been a high-risk therapeutic option for symptomatic drug-refractory patients with PHT. Results have been unpredictable due to limited knowledge of the optimal shunt-quantity.

METHODS

In nine dogs, an 8-mm shunt-prosthesis was inserted between the superior vena cava (SVC) and the left atrium. With pulmonary artery (PA) banding, mean (± SEM) systolic right ventricular pressure increased from 37 ± 1 mm Hg at baseline to 44 ± 1 mm Hg (moderate PHT, P = 0.005) and 50 ± 2 mm Hg (severe PHT, P < 0.001). Shunt-flow was adjusted by total (forcing all flow through the shunt) or partial occlusion of the SVC and partial or total clamping of the shunt. Caval-, shunt-, and aortic-flow were measured by ultrasonic flow-probes. Blood gases were drawn from the aortic root and PA.

RESULTS

At severe PHT, a shunt-flow of 11 ± 1% of CO (253 ± 90 mL/min) increased CO significantly by 25% (1.8 ± 0.1 to 2.4 ± 0.2 L/min, P = 0.005) causing an increase of systemic oxygen delivery index (DO2 I) by 23% (309 ± 23 to 399 ± 32 mL/min/m(2), P = 0.035). Arterial O2 -saturation did not change significantly until a shunt-flow of 18 ± 2% was exceeded, causing a drop from 96 ± 1% to 84 ± 4% (P = 0.013). At moderate PHT, CO or DO2 I did not improve significantly at any shunt-flow.

CONCLUSIONS

In severe PHT, a shunt-flow of 11% of CO represented the ideal shunt-fraction. Augmentation of CO compensated for declined O2 -saturation due to right-to-left shunting and improved DO2 I. In moderate PHT, AS is less promising.

Clinical and pathologic comparison of simple left-to-right shunt congenital heart disease and transposition of the great arteries with ventricular septal defect

BACKGROUND

This study aimed to compare clinical and pathologic data for selected patients with congenital heart disease (CHD) and severe pulmonary hypertension (PH) treated with a diagnostic-treatment-and-repair strategy and to compare results for patients with pulmonary vascular disease (PVD) with simple left-to-right shunt CHD with patients with transposition of the great arteries (TGA) and ventricular septal defect (VSD).

METHODS

Group I comprised 38 patients with simple left-to-right shunt CHD and severe PH; group II included 11 older patients with TGA with VSD and severe PH; and group III comprised 6 autopsy cases of individuals with a normal circulation. The nature of the pulmonary arteries was determined by the Heath-Edwards classification system. All specimens were quantitatively analyzed.

RESULTS

Group I showed 31 patients with a change to grade I, 3 patients were grade II, 3 patients were grade III, and only 1 patient was grade IV. Group II showed 7 patients with a change to grade I, 2 patients were grade II, 1 patient was grade III, and only 1 patient was grade IV. The media wall thickness percentage (%MT), the media wall area percentage (%MS), and arteriole density were significantly higher in groups I and II than in group III. %MS was significantly higher in group II than in group I; no significant differences in %MT and arteriole density could be found between groups I and II.

CONCLUSIONS

The PVD in these selected patients with CHD and severe PH who were cared for with a diagnostic-treatment-and-repair strategy is generally reversible, and the changes in PVD in the patients with TGA and VSD were similar to those in the patients with simple left-to-right shunt CHD.

Overview of current therapeutic approaches for pulmonary hypertension

There have been tremendous strides in the management of pulmonary hypertension over the past 20 years with the introduction of targeted medical therapies and overall improvements in surgical treatment options and general supportive care. Furthermore, recent data shows that the survival of those with pulmonary arterial hypertension is improving. While there has been tremendous progress, much work remains to be done in improving the care of those with secondary forms of pulmonary hypertension, who constitute the majority of patients with this disorder, and in the optimal treatment approach in those with pulmonary arterial hypertension. This article will review general and targeted medical treatment, along with surgical interventions, of those with pulmonary hypertension.

Atrial septostomy in patients with pulmonary hypertension: should it be recommended?

Treatment options for patients with advanced pulmonary hypertension (PH) are limited. Iatrogenic creation of an interatrial communication (i.e., atrial septostomy [AS]) has been suggested as a possible treatment option or as a bridge to transplantation in selected patients and has been incorporated into current PH guidelines. Uptake of the procedure has been slow and the worldwide experience with AS is limited to approximately 280 published cases, over a period of more than 25 years. The rationale for creating an AS has been provided by the observation that patients with congenital heart disease, shunt lesions and PH have a better survival compared with patients with idiopathic PH. We review pathophysiologic data and the published clinical experience and discuss the rationale, indication and potential pitfalls of AS in patients with severe PH.

A modified technique of stent fenestration of the interatrial septum improves patients with pulmonary hypertension

AIMS

A significant number of patients with pulmonary hypertension are resistant to medical therapy. We wanted to evaluate whether the modified technique of stent fenestration of the interatrial septum would be feasible and safe, and offer clinical benefit.

METHODS AND RESULTS

The medical records of all patients with pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension who underwent a stent fenestration of the interatrial septum between 2001 and 2008 were reviewed. In all fifteen patients (12 female, mean age 48.2 +/- 20.5 years) a successful fenestration procedure could be performed. Median follow-up time between diagnosis and fenestration was 2.3 years (range from 0.5 to 18.6 years). Mean event free survival since diagnosis and after septostomy was 9.8 +/- 2.9 and 3.2 +/- 0.8 years, respectively. When one extreme outlier was excluded, the 6 min walk distance improved significantly from 309 +/- 69 m immediately before fenestration to 374 +/- 84 m, 3-4 months after fenestration (n = 8, paired t-test, P = 0.03). No stent occlusion occurred.

CONCLUSION

The modified stent fenestration technique is feasible and safe in patients with severe pulmonary hypertension. In a selected group of patients, functional capacity might improve although disease progression continues.

Evaluating Operability in Adults with Congenital Heart Disease and the Role of Pretreatment with Targeted Pulmonary Arterial Hypertension Therapy

Despite recent advances in cardiac surgery that have allowed repair of congenital heart defects at a very young age, pulmonary arterial hypertension (PAH) secondary to congenital heart disease (CHD) remains a major problem. In its most severe form, the Eisenmenger syndrome, PAH and its complications result in a significant increase in morbidity and mortality and also greatly affect the quality of life of patients.

Surgical therapies for pulmonary arterial hypertension

Surgical therapies for the treatment of pulmonary arterial hypertension typically are reserved for patients who are deemed to be refractory to medical therapy and have evidence of progressive right-sided heart failure. Atrial septostomy, a primarily palliative procedure, may stave off hemodynamic collapse from right-sided heart failure long enough to permit a more definitive surgical treatment such as lung or combined heart-lung transplantation. This article discusses indications for and results of atrial septostomy and lung and heart-lung transplantation in patients who have pulmonary arterial hypertension.

Atrial septostomy in treatment of end-stage right heart failure in patients with pulmonary hypertension

BACKGROUND

Right ventricular (RV) failure is the main cause of death in patients with pulmonary hypertension (PH). Balloon atrial septostomy (BAS) is believed to relieve symptoms of PH by increasing systemic flow and reducing RV preload.

METHODS

Fourteen BAS procedures were performed in 11 patients (5 men and 6 women; mean [+/- SD] age, 33 +/- 12 years) with RV failure in the course of PH that was refractory to conventional treatment. BAS consisted of a puncture of the interatrial septum and subsequent dilatations with balloons of increasing diameter in a step-by-step manner.

RESULTS

After BAS, the mean oxygen saturation of aortic blood decreased (before, 93 +/- 4%; after, 84 +/- 4%; p = 0.001), while mean cardiac index increased (before, 1.54 +/- 0.34 L/min/m(2); after, 1.78 +/- 0.35 L/min/m(2); p = 0.001), resulting in a positive trend for mean systemic oxygen transport (before, 270 +/- 64 mL/min; after, 286 +/- 81 mL/min; p = 0.08). Pulmonary vascular resistance (PVR) slightly increased immediately after the procedure, and this rise inversely correlated with mixed venous blood partial oxygen pressure both before BAS (r = -0.69; p = 0.009) and after BAS (r = -0.64; p = 0.018). Mean functional class improved from 3.2 +/- 0.4 to 2.6 +/- 0.7 (p = 0.03) after 1 month. At follow-up (mean time to follow-up, 8.1 +/- 6.2 months; range, 0.8 to 20.2 months), seven patients died and two underwent lung transplantation. There was no difference in the survival rate compared to that obtained from National Institutes of Health equation. A significant size reduction in the created defect was observed in six patients, requiring repeat BAS procedures in three cases.

CONCLUSIONS

The current BAS technique improves cardiac index and functional class without significant periprocedural complications, except for a transient increase in PVR related to acute desaturation of mixed venous blood. At long-term follow-up, a high incidence of spontaneous decrease in orifice size has been observed.

Atrial septostomy improves survival in select patients with pulmonary hypertension

BACKGROUND

Atrial septostomy is a palliative treatment for patients with pulmonary hypertension (PHTN) refractory to vasodilator therapy. Limited data exist in the pediatric population and in patients with repaired congenital heart defects.

METHODS

We performed a retrospective analysis of hemodynamic and symptomatic changes in patients with PHTN who underwent an atrial septostomy at our institution.

RESULTS

Forty-six atrial septostomies were performed on 43 patients. Patient ages ranged from 0.3 to 30 years (median 12.5). Of 43 patients, 29 had primary PHTN, 10 had PHTN associated with repaired congenital heart defects, and 4 had other secondary causes of PHTN. Mean baseline pulmonary vascular resistance was 35 +/- 17 Wood units, and mean pulmonary artery pressure was 74 +/- 19 mm Hg. Patients surviving > or = 30 days had immediate improvement in cardiac index (from 2.3 to 2.9 L x min(-1) x m(-2), P < .0001), right atrial pressure (RAp) (from 9.9 to 8.3 mm Hg, P < .05), and oxygen delivery (from 424 to 491 mL O2 per minute, P < .01), with a decrease in systemic oxygen saturation (from 93% to 86%, P < .001). Pulmonary artery pressure was unchanged (P = .3). New York Heart Association class and symptoms of syncope improved (P < .01). Event-free survival at 1, 2, and 3 years was 84%, 77%, and 69%, respectively. Using the National Institutes of Health Registry model, predicted survival probability significantly improved (P < .001). Ten patients (22%) died within 30 days of catheterization. Mortality was associated with preceding decompensations in the intensive care unit (6/10, P < .001) and a higher RAp (21.4 vs 9.8 mm Hg, P < .001).

CONCLUSIONS

Atrial septostomy provides symptomatic and hemodynamic improvement in cardiac index and RAp. Risk of septostomy is increased in patients with preceding decompensation or a RAp > 18 mm Hg.

In utero cardiac fetal surgery: laser atrial septotomy in the treatment of hypoplastic left heart syndrome with intact atrial septum

OBJECTIVE

The purpose of this study was to report a novel technique, laser atrial septotomy, for the in utero treatment of hypoplastic left heart syndrome with intact atrial septum.

STUDY DESIGN

In utero atrial septotomy by Neodymium-YAG laser photofulguration in a fetus with hypoplastic left heart syndrome (HLHS) and intact atrial septum was performed at 30 4/7 weeks of gestation. Percutaneous fetal cardiocentesis was performed to guide a contact (Neodymium-YAG) laser fiber into the right atrium with the objective of creating an interatrial communication by photofulguration of the septal tissue.

RESULTS

New onset of blood flow from the left to the right atrium was confirmed by color Doppler imaging during the procedure. The neoatrial septal defect remained patent until delivery. A 3400-g neonate was born by spontaneous vaginal delivery at 37 weeks of gestation. A first stage Norwood procedure was performed on the first day of life and surgical correction of an obstructed right pulmonary vein at 3 months. Although pulmonary vascular resistance was normal at cardiac catheterization at 2 months of age, the infant died at 5 months of age from multiple organ failure. An autopsy was declined.

CONCLUSION

In utero laser atrial septotomy is feasible. Further experience is necessary to determine the risks and benefits of this technique for the treatment of fetuses hypoplastic left heart syndrome with intact atrial septum.

Paediatric pulmonary vascular disease

Pulmonary vascular disease comprises any congenital or acquired pathology of the intrinsic pulmonary vessels with the unique feature of pulmonary arteries carrying unsaturated blood and pulmonary veins carrying oxygenated blood. Pulmonary hypertension (PH) ensues when pulmonary vascular disease affects at least 50% of the capillary resistance vessels, i.e. pulmonary pre-acinar and intra-acinar arteries (so-called pre-capillary PH), or when pressure in the pulmonary venous system distal to the capillaries rises above a mean of 15 mmHg (so-called post-capillary PH). PH is defined by a mean pulmonary arterial pressure above 25 mmHg at rest. Vasoconstriction, remodelling and thrombosis of small pulmonary arteries lead to an increase in pulmonary vascular resistance. The consequence is failure of the afterload-intolerant right ventricle. In this review, pulmonary vascular disease in children will be addressed according to the 2003 World Health Organisation (Venice) classification of PH.