CONTACT:
ACC – Amanda Jekowsky, (202) 375-6645
AHA – Maggie Francis, (214) 706-1382

March 30, 2009

Journal of the American College of Cardiology (JACC) (http://content.onlinejacc.org) , and Circulation:
Journal of the American Heart Association (http://circ.ahajournals.org).

Highlights from the Expert Consensus Document on Pulmonary Hypertension include:

1. Pulmonary arterial hypertension (PAH) is a syndrome resulting from restricted flow through the pulmonary arterial circulation, resulting in increased pulmonary vascular
resistance (PVR) and ultimately in right heart failure. Multiple pathogenic pathways are responsible for modifying smooth muscle and endothelial cells and adventitia, and the imbalance in the vasoconstrictor/vasodilator milieu.

2. The prevalence of PAH is 15 per million in the French registry. Idiopathic PAH (IPAH) is the most common type of PAH and is more common in women. Familial PAH often results from a mutation in the bone morphogenic protein receptor-2 and is inherited as an autosomal dominant disease with incomplete penetrance and genetic anticipation. PAH is also associated with congenital heart disease (CHD), connective tissue diseases, drugs and toxins, human immunodeficiency virus, portal hypertension, hemoglobinopathies, and myeloproliferative disorders. CHD occurs in 8 per 1,000 live births, and PAH will develop in 30% of those with nonrepaired CHD.

3. The 1-year mortality in PAH is about 15% on modern therapy. Predictors of a poor prognosis include: advanced functional class, poor exercise capacity, high right atrial pressure, significant right ventricular (RV) dysfunction, RV failure, low cardiac index, elevated brain natriuretic peptide, and the scleroderma spectrum of diseases.

4. Patients at sufficient risk for the development of PAH to warrant periodic screening include those with a family history of IPAH, scleroderma spectrum of diseases, and portal hypertension who are undergoing evaluation for liver transplantation. The most appropriate study to obtain in patients suspected of having PH is an echocardiogram.

5. The diagnosis of PAH requires confirmation with a complete right heart catheterization. The hemodynamic definition of PAH is a mean pulmonary artery pressure >25 mm Hg; a pulmonary capillary wedge pressure (PCW), left atrial pressure, or left ventricular end-diastolic pressure ≤15 mm Hg; and a PVR >3 Wood units. Acute vasodilator testing should be performed in experienced centers on IPAH patients to screen eligibility for long-term calcium channel blocker (CCB) therapy. Exceptions include those with overt right heart failure or hemodynamic instability.

6. General treatment measures include diet, exercise, appropriate vaccinations, and avoidance of pregnancy. Warfarin anticoagulation is recommended in all patients with IPAH. Diuretics are used for symptomatic management of RV volume overload. Oxygen is recommended to maintain oxygen saturation >90%. Acute responders to vasodilator testing treated with CCB should be followed closely for both the safety and the efficacy of this therapy.

7. Continuous intravenous epoprostenol improves exercise capacity, hemodynamics, and survival in IPAH and is the preferred treatment option for the most critically ill patients. Treprostinil, a prostanoid, may be delivered via either continuous intravenous or subcutaneous infusion. Iloprost is a prostanoid delivered by an adaptive aerosolized device 6 times daily.

8. The endothelin receptor antagonists (ETAs) are oral therapies that improve exercise capacity in PAH. Liver function tests must be monitored indefinitely on a monthly basis. Phosphodiesterase (PDE)-5 inhibitors also improve exercise capacity and hemodynamics in PAH. Patients with poor prognostic indexes should be initiated on parenteral therapy, while patients with class II or early III symptoms can commence therapy with either ETAs or PDE-5 inhibitors. Initial trials suggest that combination therapy may be useful. Lung transplantation is an option for selected patients who progress despite optimal medical management.

9. Due to the complex nature of the disease and its treatments, PAH patients must be closely followed by experienced physicians and nurse clinicians. In general, office visits should be more frequent for patients with advanced symptoms, right heart failure, and advanced hemodynamics and those on parenteral or combination therapy. Most experts obtain an assessment of functional class and exercise capacity, such as a 6-minute walk or graded treadmill test, with each office visit.

10. Any disorder that elevates left heart filling pressures, including systolic dysfunction, diastolic dysfunction, and valvular heart disease, can result in elevated pulmonary artery pressures. In rare instances, PAH-specific therapy may be considered if the underlying cause has been optimally treated, the PCW is normal or minimally elevated, and the transpulmonary gradient and PVR are significantly elevated. The latter is known as “disproportionate” PH or greater than expected on the basis of the elevated left heart pressure or lung disease. The potential adverse effects of PAH-specific therapies in such patients include worsening fluid retention, pulmonary edema, and ventilation perfusion mismatch.

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