Heart Blood Pressure Tool Unable to Predict Survival of PAH Patients on Remodulin, Study Finds

Patricia Inácio, PhD avatar

by Patricia Inácio, PhD |

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A tool for estimating blood pressure on the left side of the heart is unable to predict the long-term survival of pulmonary hypertension patients taking Remodulin, a study reports.

The tool, pulmonary capillary wedge pressure, or PCWP, is used to estimate blood pressure in the left atrium. United Therapeutics makes Remodulin, also known as injected treprostinil.

The research, “Impact of Pulmonary Capillary Wedge Pressure on Long-Term Mortality in Patients With Pulmonary Arterial Hypertension Treated With Parenteral Trepostinil,” was published in the journal Heart, Lung and Circulation.

Researchers studied 743 PAH patients who underwent right heart catheterization before starting on Remodulin. The patients took part in the TRUST-1 (NCT00494533) and SC-TRE (NCT02893995) clinical trials.

The research team looked at the death rates of Remodulin-treated patients. The team placed them in one of three PCWP categories at the start of the four-year study: low, intermediate or high blood pressure.

The team also analyzed patients’ demographics, the cause of their disease and its characteristics before the study started. These parameters included age, gender, race, an exercise-capacity measure known as six-minute walk distance (6MWD), and a measure of shortness of breath known as the BORG dyspnoea score.

Of the patients studied, 280 (37.7 percent) had a mean PCWP of 8 mmHg, putting them in the lowest blood pressure group; 233 patients (31.4 percent) had a median PCWP between 8 and 11 mmHg, putting them in the intermediate group; and 230 patients (31 percent) had a mean PCWP above 11 mmHg, putting them in the highest blood pressure group.

Age and gender were similar across the three groups, as well as the cause of PAH, “with idiopathic PAH and congenital systemic-to-pulmonic shunts serving as the predominant etiologies [causes],” researchers wrote.

No differences in 6MWD and BORG dyspnoea score were found between the groups.

The key finding that there were no differences in the groups’ death rates. Overall, all-cause mortality rates at 1 year were: 10.1 percent for the group with PCWP 8 mmHg, 9.9 percent for patients with PCWP 8-11 mmHg, and 10 percent for the group with PCWP above 11 mmHg. At year 4, the percentage of all-cause mortality was still similar between the groups — 16.8 percent in the first, 21.9 percent in the second, and 19.2 percent in the third.

There was no correlation between levels of PCWP and patients’ survival rates up to four years. Predictors of mortality at four years included being older, belonging to a non-white race, and higher pulmonary vascular resistance.

Overall, “in this study of patients with PAH receiving concomitant parenteral treprostinil, PCWP was not associated with long-term all-cause mortality. Further studies examining prognostic indicators in patients with PAH optimized on guideline-based therapies are warranted,” the team concluded.