The prevalence of pulmonary arterial hypertension before and after atrial septal defect closure at adult age: A systematic review.

BACKGROUND: The development or persistence of pulmonary arterial hypertension (PAH) after atrial septal defect (ASD) closure at adult age is associated with a poor prognosis. The objective of this review was to investigate the prevalence of PAH before and after ASD closure and to identify factors that are associated with PAH. METHODS: EMBASE and MEDLINE databases were searched for publications until March 2017. All studies reporting the prevalence of PAH or data on pulmonary artery pressures both before and after surgical or percutaneous ASD closure in an adult population (≥16 years of age) were included. Papers were methodologically checked and data was visualized in tables, bar charts and plots. RESULTS: A total of 30 papers were included. The prevalence of PAH ranged from 29% to 73% before ASD closure and from 5% to 50% after closure; being highest in older studies, small study cohorts, and studies with high rates of loss to follow-up. The pooled systolic pulmonary artery pressure (PAP) was 43±13 before ASD closure and 32±10 after closure. The overall mean PAP was 34±10 before closure and 28±8 after closure. Studies with a higher mean PAP before closure and a higher mean age of the study cohort reported greater PAP reductions. CONCLUSIONS: The prevalence of PAH and mean pulmonary pressures decreased in all studies, regardless of the mean age or pulmonary pressures of the cohort. The reported prevalence of PAH after ASD closure is substantial, although widely varying (5%-50%), which is likely affected by selection of the study cohort.

Insights Into the Effects of Low-Level Vagus Nerve Stimulation on Atrial Electrophysiology: Towards Patient-Tailored Cardiac Neuromodulation.

BACKGROUND: Low-level vagus nerve stimulation through the tragus (tLLVNS) is increasingly acknowledged as a therapeutic strategy to prevent and treat atrial fibrillation. However, a lack in understanding of the exact antiarrhythmic properties of tLLVNS has hampered clinical implementation. OBJECTIVES: In this study, the authors aimed to study the effects of tLLVNS on atrial electrophysiology by performing intraoperative epicardial mapping during acute and chronic tLLVNS. METHODS: Epicardial mapping of the superior right atrium was performed before and after arterial graft harvesting in patients undergoing coronary artery bypass grafting without a history of atrial fibrillation. The time needed for arterial graft harvesting was used to perform chronic tLLVNS. Electrophysiological properties were compared before and during chronic tLLVNS. RESULTS: A total of 10 patients (median age 74 years [IQR: 69-78 years]) underwent tLLVNS for a duration of 56 minutes (IQR: 43-73 minutes). During acute and chronic tLLVNS, a shift of the sinoatrial node exit site toward a more cranial direction was observed in 5 (50%) patients. Unipolar potential voltage increased significantly during acute and chronic tLLVNS (3.9 mV [IQR: 3.1-4.8 mV] vs 4.7 mV [IQR: 4.0-5.3 mV] vs 5.2 mV [IQR: 4.8-7.0 mV]; P = 0.027, P = 0.02, respectively). Total activation time, slope of unipolar potentials, amount of fractionation, low-voltage areas and conduction velocity did not differ significantly between baseline measurements and tLLVNS. Two patients showed consistent "improvement" of all electrophysiological properties during tLLVNS, while 1 patient appeared to have no beneficial effect. CONCLUSIONS: We demonstrated that tLLVNS resulted in a significant increase in unipolar potential voltage. In addition, we observed the following in selective patients: 1) reduction in total activation time; 2) steeper slope of unipolar potentials; 3) decrease in the amount of fractionation; and 4) change in sinoatrial node exit sites.

In-vivo Sino-Atrial Node Mapping in Children and Adults With Congenital Heart Disease.

Background: Sinus node dysfunction (SND) and atrial tachyarrhythmias frequently co-exist in the aging patient with congenital heart disease (CHD), even after surgical correction early in life. We examined differences in electrophysiological properties of the sino-atrial node (SAN) area between pediatric and adult patients with CHD. Methods: Epicardial mapping of the SAN was performed during sinus rhythm in 12 pediatric (0.6 [0.4-2.4] years) and 15 adult (47 [40-55] years) patients. Unipolar potentials were classified as single-, short or long double- and fractionated potentials. Unipolar voltage, relative R-to-S-amplitude ratio and duration of all potentials was calculated. Conduction velocity (CV) and the amount of conduction block (CB) was calculated. Results: SAN activity in pediatric patients was solely observed near the junction of the superior caval vein and the right atrium, while in adults SAN activity was observed even up to the middle part of the right atrium. Compared to pediatric patients, the SAN region of adults was characterized by lower CV, lower voltages, more CB and a higher degree of fractionation. At the earliest site of activation, single potentials from pediatrics consisted of broad monophasic S-waves with high amplitudes, while adults had smaller rS-potentials with longer duration which were more often fractionated. Conclusions: Compared to pediatric patients, adults with uncorrected CHD have more inhomogeneous conduction and variations in preferential SAN exit site, which are presumable caused by aging related remodeling. Long-term follow-up of these patients is essential to demonstrate whether these changes are related to development of SND and also atrial tachyarrhythmias early in life.

Risk Factors for Pulmonary Hypertension in Adults After Atrial Septal Defect Closure.

Atrial septal defect (ASD) closure is performed to prevent pulmonary hypertension (PH), which is associated with poor outcome. This study investigated the prevalence of PH in adults before and after ASD closure and explored associations between patient characteristics and PH after ASD closure. Consecutive adult patients who underwent surgical or percutaneous ASD closure in the Erasmus MC, the Netherlands, were included (2000 to 2014). Echocardiograms before and after ASD closure were retrospectively assessed. Patients were categorized into 3 groups (no PH, possible PH, and PH) based on tricuspid regurgitation velocity (<2.9, 2.9 to 3.4, and ≥3.4 m/s) or mean pulmonary arterial pressure (<20, 20 to 24, and ≥25 mm Hg). Cox regression was performed to identify associations between patient characteristics and PH after ASD closure. Of the 244 eligible patients who underwent ASD closure, 198 (81%) had echocardiograms both before and median 15 (interquartile range 12 to 35) months after ASD closure (median age at closure 45 [interquartile range 30 to 57] years, 75% woman). The prevalence of PH was 13.1% (n = 26) before ASD closure and 5.0% (n = 10) after closure. New York Heart Association III to IV (hazard ratio [HR] 11.07, 95% confidence interval [CI] 3.12 to 39.29, p <0.001), pulmonary disease (HR 10.43, 95% CI 2.12 to 51.21, p = 0.004), cardiac medication use (HR 3.96, 95% CI 1.02 to 15.34, p = 0.047), right ventricular fractional area change (HR 0.87, 95% CI 0.81 to 0.93, p <0.001), and tricuspid annular plane systolic excursion (HR 0.75, 95% CI 0.59 to 0.95, p = 0.018) were significantly associated with PH. In conclusion, adult patients with low pulmonary pressures before ASD closure are not at risk of PH after closure. Nevertheless, PH remained prevalent in approximately 5% of patients. Especially those patients with high New York Heart Association functional class, presence of pulmonary disease, cardiac medication use and impaired RV function at baseline are at risk.