VIENNA – New guidelines for managing patients with pulmonary hypertension have been published jointly by the European Respiratory Society and the European Society of Cardiology.

Pulmonary hypertension - an increase in blood pressure in the pulmonary vasculature - occurs in multiple diseases and clinical settings. It may be a complication of cardiac or pulmonary diseases, be due to connective tissue diseases such as scleroderma, liver disease with portal hypertension or to infections such as HIV, or be idiopathic.

The new guidelines describe five different clinical groups (plus an additional clinical group related to group 1). Two of these in particular stand out: patients with pulmonary hypertension due to

• left heart disease (group 2); or
• lung disease, such as COPD (group 3).

Indeed, as many as 60% of patients with severe left heart failure and half of those with advanced COPD will develop pulmonary hypertension - this disease is a concern for respiratory physicians as well as cardiologists. In patients suffering from COPD or pulmonary fibrosis, even “mild” pulmonary hypertension worsens their long-term prognosis.

As well as defining groups of patients, the guidelines provide a new clinical classification and a new definition of pulmonary hypertension.
Speaking at the 19th Annual Congress of the European Respiratory Society, Professor Marius Hoeper, of the Department of Respiratory Medicine, Hannover Medical School, Germany, explained that the recent evaluation of the available data has shown that normal pulmonary arterial pressure at rest is 14±3 mmHg, with an upper limit of normal at about 20 mmHg. Pulmonary hypertension is present when the mean pulmonary arterial pressure at rest (assessed by mandatory right heart catheterisation) equals or exceeds 25 mmHg, in the presence of a pulmonary capillary wedge pressure = 15 mmHg.

While the upper limit at rest remains unchanged in the new guidelines, pulmonary pressure measurements during exercise are no longer being taken into consideration.

According to Dr. Hoeper, the previous definition, which included an upper arterial pressure limit of 30 mmHg with exercise, has been revised because its values were too variable, showing both age-related and individual variations. “Healthy individuals can reach much higher levels than 30 mmHg on exercise,” says Dr Hoeper.

Pulmonary arterial hypertension: Early treatment is favoured

Although pulmonary hypertension is haemodynamically defined by an increase in pulmonary arterial pressure, not all types of pulmonary hypertension are classed as pulmonary arterial hypertension (PAH). In fact, the diagnosis of PAH (group 1) requires the exclusion of all other groups of pulmonary hypertension. Pulmonary veno-occlusive disease, chronic thromboembolic pulmonary hypertension and pulmonary hypertension due to left heart disease or lung disease are all considered to be different entities.

Not only do the 2009 guidelines provide better and clearer definitions for diagnosis, they propose a new diagnostic algorithm for recognising affected patients as early as possible. The guidelines emphasise the identification and risk stratification of patients. Out of the different patient groups, patients in the pulmonary arterial hypertension group tend to be younger and to be affected by more severe disease. A large section of the guidelines, including specific drug therapy recommendations and an evidence-based treatment algorithm, deals with these patients, mainly because specific treatments are available.

There have been rapid advances in the treatment of pulmonary arterial hypertension.
In the past few years, eight drugs from three different pharmacological classes, with various administration routes, have been approved for the condition, leading not only to a significant improvement in patients’ symptoms and rate of progression, but actually reducing mortality substantially. These drugs include phosphodiesterase-5 inhibitors, endothelin receptor antagonists and prostanoids.

Treatment should be started as early as possible in patients presenting with WHO functional class II (a slight limitation of physical activity), using one or two substances from the first two pharmacological classes. There is growing evidence that combination treatment may be superior. However, for patients in WHO functional class IV (who cannot carry out any physical activity without symptoms), intravenous epoprostenol remains the first-line treatment.

As these new guidelines illustrate, treating patients with pulmonary arterial hypertension is a complex matter, combining different drugs and interventions with an ongoing evaluation of disease severity and response to treatments and a programme of general and supportive care.

2009, week 44