Saudi Guidelines on the Diagnosis and Treatment of Pulmonary Hypertension: Pulmonary arterial hypertension associated with congenital heart disease

Sildenafil's Early, Late Impact on Ventricular Septal Repair: Older Children Using the Double Patch

BACKGROUND

Delayed diagnosis in children with a ventricular septal defect (VSD) is common in developing countries. Consequently, they present with elevated pulmonary vascular resistance (PVR) and pulmonary arterial hypertension (PAH). We introduced the double-flap valve VSD patch closure technique (DFV) in 1996 to reduce early post- operative risk. Long-term results are presented herein.

METHODS

This is a retrospective single-institution study on DFV patients performed between 5/1996 and 7/2015. Beginning in 2005 all candidates for DFV received sildenafil pre-and post-operatively. Pre-operative catheterization data, operative, post-operative, hospital and follow-up data were analyzed.

RESULTS

Forty patients received the DFV surgery. Patient demographics were comparable between sildenafil and non-sildenafil groups. Lost to follow up 1/39 (2.6%). Early mortality: 1/40 (2.5%), late mortality: 1/38 (2.6%). Sildenafil improved pre-op saturation, improved pre-operative hemodynamics as well as shortened prost-operative ventilation time. In both groups abnormal hemodynamic parameters improved with 100% oxygen challenge. The median age at late follow-up was 26.3 years (20.9; 29.9[25%; 75% Intra-quartile range]) and the median time since operation was 19.2 years (11.4; 22.7). Current discharge survival was 97.3%. Patients with severe PAH in late follow-up was 18%. Multi-variate analysis revealed only baseline PVR/SVR ≥ 0.8 as a significant predictor of late severe PAH.

CONCLUSIONS

Our long-term follow-up demonstrates that 60% of the patients will achieve normal or near normal PA pressures. Furthermore, we have demonstrated that sildenafil improves. pre-operative hemodynamics and post-operate management. Children with VSD, elevated PVR and PAH should not be denied operation.

Pulmonary hypertension in the developing world: Local registries, challenges, and ways to move forward

Pulmonary hypertension (PH) is a disease that can only be appropriately managed in the ‘rich’ developed countries, as both diagnostic and therapeutic interventions are extremely expensive and expectations for these to be adopted by the developing, economically-challenged countries are neither practical nor realistic. Furthermore, most of the enormous advances in understanding the pathobiology of PH and the subsequent evidence-based diagnostic and complex treatment algorithms came from the developed world.

Review of evidence for bosentan therapy for treatment of Eisenmenger syndrome

BACKGROUND AND PURPOSE

Eisenmenger syndrome (ES) is a rare condition caused by a right-to-left cyanotic shunt. To date, only heart-lung transplant has been shown to be curative. Bosentan is the only medication studied with a double-blind placebo-controlled randomized trial for management of this condition. The intent of this article is to explore the literature surrounding bosentan in ES and assess its efficacy.

METHODS

A literature review was conducted with no limitation on date. Titles were scanned for applicability, and abstracts of those articles found to be pertinent were reviewed. Those articles considered relevant based on the abstract were read in entirety.

CONCLUSIONS

Eisenmenger syndrome remains incurable except through heart-lung transplant. Although no specific medical treatment or algorithm exists, three pharmacological classes show promise in disease management: endothelin receptor antagonists, phosphodiesterase inhibitors, and prostacyclins. Combined therapy with these agents may improve cardiopulmonary function. Bosentan has not been proven as a monotherapy for ES and is not appropriate in all patients as side effects are commonly reported.

IMPLICATIONS FOR PRACTICE

Further study is required to assess efficacy of combination therapy and utilization as a bridge to transplant or surgical correction of the underlying defect.

Quantification of the area and shunt volume of multiple, circular, and noncircular ventricular septal defects: A 2D/3D echocardiography comparison and real time 3D color Doppler feasibility determination study

BACKGROUND

Quantification of defect size and shunt flow is an important aspect of ventricular septal defect (VSD) evaluation. This study compared three-dimensional echocardiography (3DE) with the current clinical standard two-dimensional echocardiography (2DE) for quantifying defect area and tested the feasibility of real time 3D color Doppler echocardiography (RT3D-CDE) for quantifying shunt volume of irregular shaped and multiple VSDs.

METHODS

Latex balloons were sutured into the ventricles of 32 freshly harvested porcine hearts and were connected with tubing placed in septal perforations. Tubing was varied in area (0.13-5.22 cm²), number (1-3), and shape (circle, oval, crescent, triangle). A pulsatile pump was used to pump "blood" through the VSD (LV to RV) at stroke volumes of 30-70 mL with a stroke rate of 60 bpm. Two-dimensional echocardiography (2DE), 3DE, and RT3D-CDE images were acquired from the right side of the phantom.

RESULTS

For circular VSDs, both 2DE and 3DE area measurements were consistent with the actual areas (R² = 0.98 vs 0.99). For noncircular/multiple VSDs, 3DE correlated with the actual area more closely than 2DE (R² = 0.99 vs 0.44). Shunt volumes obtained using RT3D-CDE positively correlated with pumped stroke volumes (R² = 0.96).

CONCLUSIONS

Three-dimensional echocardiography (3DE) is a feasible method for determining VSD area and is more accurate than 2DE for evaluating the area of multiple or noncircular VSDs. Real-time 3D color Doppler echocardiography (RT3D-CDE) is a feasible method for quantifying the shunt volume of multiple or noncircular VSDs.

Vasopressors induce passive pulmonary hypertension by blood redistribution from systemic to pulmonary circulation

Vasopressors are widely used in resuscitation, ventricular failure, and sepsis, and often induce pulmonary hypertension with undefined mechanisms. We hypothesize that vasopressor-induced pulmonary hypertension is caused by increased pulmonary blood volume and tested this hypothesis in dogs under general anesthesia. In normal hearts (model 1), phenylephrine (2.5 μg/kg/min) transiently increased right but decreased left cardiac output, associated with increased pulmonary blood volume (63% ± 11.8, P = 0.007) and pressures in the left atrium, pulmonary capillary, and pulmonary artery. However, the trans-pulmonary gradient and pulmonary vascular resistance remained stable. These changes were absent after decreasing blood volume or during right cardiac dysfunction to reduce pulmonary blood volume (model 2). During double-ventricle bypass (model 3), phenylephrine (1, 2.5 and 10 μg/kg/min) only slightly induced pulmonary vasoconstriction. Vasopressin (1U and 2U) dose-dependently increased pulmonary artery pressure (52 ± 8.4 and 71 ± 10.3%), but did not cause pulmonary vasoconstriction in normally beating hearts (model 1). Pulmonary artery and left atrial pressures increased during left ventricle dysfunction (model 4), and further increased after phenylephrine injection by 31 ± 5.6 and 43 ± 7.5%, respectively. In conclusion, vasopressors increased blood volume in the lung with minimal pulmonary vasoconstriction. Thus, this pulmonary hypertension is similar to the hemodynamic pattern observed in left heart diseases and is passive, due to redistribution of blood from systemic to pulmonary circulation. Understanding the underlying mechanisms may improve clinical management of patients who are taking vasopressors, especially those with coexisting heart disease.

The Saudi Initiative for Asthma - 2016 update: Guidelines for the diagnosis and management of asthma in adults and children

This is an updated guideline for the diagnosis and management of asthma, developed by the Saudi Initiative for Asthma (SINA) group, a subsidiary of the Saudi Thoracic Society. The main objective of SINA is to have guidelines that are up to date, simple to understand and easy to use by nonasthma specialists, including primary care and general practice physicians. SINA approach is mainly based on symptom control and assessment of risk as it is the ultimate goal of treatment. The new SINA guidelines include updates of acute and chronic asthma management, with more emphasis on the use of asthma control in the management of asthma in adults and children, inclusion of a new medication appendix, and keeping consistency on the management at different age groups. The section on asthma in children is rewritten and expanded where the approach is stratified based on the age. The guidelines are constructed based on the available evidence, local literature, and the current situation in Saudi Arabia. There is also an emphasis on patient-doctor partnership in the management that also includes a self-management plan.

Asymmetric Dimethyl-L-Arginine is a Biomarker for Disease Stage and Follow-Up of Pulmonary Hypertension Associated with Congenital Heart Disease

This study investigated the clinical value of plasma asymmetrical dimethyl-L-arginine (ADMA) level in the diagnosis, staging, and treatment response in congenital heart disease (CHD) patients with pulmonary arterial hypertension (PAH). This was a single-center prospective observational study in 80 CHD patients. Plasma ADMA levels were measured by enzyme-linked immunosorbent assay. Plasma ADMA levels were significantly increased in CHD patients with PAH compared with CHD patients without PAH (P < 0.01) and healthy controls (P < 0.001). In CHD patients with severe PAH, plasma ADMA levels were significantly higher in patients with Eisenmenger's syndrome (ES) than in patients exhibiting low pulmonary vascular resistance (P < 0.001). The plasma ADMA levels significantly correlated with pulmonary arterial pressure (P < 0.001) and pulmonary vascular resistance (P < 0.001) in patients with CHD. Severe PAH was identified by plasma ADMA with a cutoff value of 0.485 μmol/L (P < 0.001) with a specificity of 82.8 % and a sensitivity of 90 %. ES was identified by plasma ADMA with a cutoff value of 0.85 μmol/L (P < 0.05) with a specificity of 85.2 % and a sensitivity of 64.3 %. ADMA levels were significantly decreased after sildenafil therapy for 6 months compared with before therapy levels (0.91 ± 0.22 vs. 0.57 ± 0.30, P < 0.01). Our study suggests that plasma ADMA level may be used as a biomarker for identifying PAH in patients with CHD, assessing pulmonary vascular remodeling, and evaluating the treatment response of CHD patients with PAH to sildenafil.