Researchers have identified a noninvasive way to predict disease outcomes in patients with pulmonary arterial hypertension (PAH) that uses three-dimensional measures of the right heart ventricle.
The method allows physicians to assess the risk of deterioration without exposing patients to repetitive heart catheterization — and may offer a way to prevent disease worsening by allowing physicians to intensify treatment in time.
The study, “Prognostic value of three-dimensional echocardiographic right ventricular ejection fraction in patients with pulmonary arterial hypertension,” was published in the journal Oncotarget.
Although abnormal behavior of the heart’s right ventricle was long thought to be secondary to lung changes in PAH, research shows that characteristics of the right ventricle can offer insights into how the disease progresses.
The ventricle’s ejection fraction — that is, the percentage of blood that gets pumped out of the heart during a heartbeat — is often used as an indirect measure of its ability to contract. But other factors can impact right ventricle contraction in patients. Researchers at Keio University in Japan, for this reason, examined a range of right ventricle characteristics and compared them to measures of blood flow using right heart catheterization.
To get noninvasive measurements of the heart, the team used two methods — called speckle tracking echocardiography (ECG) and three-dimensional transthoracic ECG — in 86 PAH patients. The group was followed for an average of 423 days.
Among a range of parameters, the team found that three-dimensional right ventricular ejection fraction best correlated with lung blood flow measures. Researchers then examined how the various measures correlated with disease outcomes.
During the study, two patients died, nine were hospitalized, one underwent a pulmonary endoarterectomy (PEA), and seven had a balloon pulmonary angioplasty (BPA) for worsening right-sided heart failure.
Comparing patients with and without worsening disease, the study found that those who experienced problems were older and had more right ventricle symptoms. They also had worse values in blood flow measurements, compared to patients without symptoms of disease progression.
Again, among the right ventricle ECG parameters, the right ventricular ejection fraction differed the most between the groups.
Further analysis revealed that the mean pulmonary arterial pressure and the ejection fraction best predicted outcomes in these patients. Those with a pulmonary arterial pressure of 35 mmHg or higher fared worse than those with lower values. Patients with an ejection fraction of less than 38 percent also had worse outcomes than those with higher outputs.
Although patients with high pulmonary pressure generally had a poor prognosis, some who also had a preserved ejection fraction had better outcomes. This suggests that the three-dimensional right ventricle ejection fraction may indeed be a robust way to noninvasively assess right ventricle hemodynamics, and to predict disease outcome in PAH patients.