Atrial septal defect pulmonary hypertension


 * Associate Editors-In-Chief: Priyamvada Singh, MBBS [mailto:psingh@perfuse.org]; ; Assistant Editor-In-Chief: Kristin Feeney, B.S. [mailto:kfeeney@perfuse.org]

Overview
Atrial septal defect patients who develop severe fixed pulmonary hypertension have poor prognosis irrespective of medical or surgical therapies compared to patients with normal pulmonary artery pressure.

Pulmonary hypertension and atrial septal defects
Patients with pulmonary hypertensive conditions face additional challenges with atrial septal defect treatment.

1) In patients with severe fixed pulmonary hypertension (pulmonary vascular resistance is ≥ 15 Wood units) the prognosis is not very good despite medical or surgical therapy.

2) On contrary, an inter-atrial communication is considered advantageous in these conditions as the communication help in decompressing the right side of heart.

3) Research have found that surgical, medical, and natural disease progression had similar high mortality rates.

4) Patients with less severe forms of pulmonary hypertension have more favorable outcomes to medical and surgical therapy.

5) If there is a suspicion that pulmonary hypertension is present, the evaluation may include a right heart catheterization. This involves placing a catheter in the venous system of the heart and measuring pressures and oxygen saturations in the superior vena cava, inferior vena cava, right atrium, right ventricle, pulmonary artery, and in the wedge position.

6) Individuals with a pulmonary vascular resistance (PVR) of ≤ 7 wood units show regression of symptoms (including NYHA functional class).

7) On the other hand, individuals with a PVR of ≥ 15 wood units have increased mortality associated with closure of the ASD.

8) Surgical mortality due to closure of an ASD is lowest when the procedure is performed prior to the development of significant pulmonary hypertension.

9) The lowest mortality rates are achieved in individuals with a pulmonary artery systolic pressure of ≤ 40 mm Hg.

Supportive trial data

 * In a study done by Steele et al on 702 patients over 25 years, with atrial septal defects (secundum or sinus venosus type) forty patients (6%) had pulmonary vascular obstructive disease, of these patients 26 underwent surgical closure and 14 received medical treatment. The patients were followed for a median follow up of 12 years. In the follow-up less than half patients died. Of the 22 surgically treated patients with total pulmonary vascular resistance less than 15 U/m2, 19 were alive with substantial improvements in the symptoms. The rest four surgically treated patients who had pulmonary resistance greater than or equal to 15 U/m2 died during the follow-up period. The outcome of medically treated patient was worse compared to the surgically corrected patients as 4 out of 5 patients with pulmonary resistance less than 15 U/m2 died. The one patient that was living had significant progression of symptoms. The other nine medically treated patients with pulmonary resistance greater than or equal to 15 U/m2, 67% (6) died and the rest survivors had progression of symptoms.