Cardiac monitoring foretells clinical deterioration in PAH

By Eleanor McDermid, Senior medwireNews Reporter

Monitoring right ventricular (RV) parameters can give advance warning of clinical deterioration in stable patients with idiopathic pulmonary arterial hypertension (PAH), research suggests.

Patients who deteriorated after 5 years of stable disease had baseline differences in RV ejection fraction (RVEF) and end-systolic volume, relative to patients who remained stable, and these parameters worsened over follow-up, despite haemodynamic measures remaining unchanged.

However, the team notes that haemodynamic changes can be very rapid in end-stage PAH, and had measurements been taken in the days or weeks preceding death they would probably have shown marked deterioration.

Baseline haemodynamic measures, such as mean pulmonary arterial pressure, pulmonary arterial wedge pressure and pulmonary vascular resistance were similar between 12 patients who remained stable and 10 who progressed. All the patients had been stable for 5 years after their diagnosis, but over a median follow-up of 10 years six patients died of cardiopulmonary causes and four underwent lung transplant.

Most baseline cardiac measures were also similar, but patients who progressed had a significantly higher average RV end-systolic volume than those who remained stable, at 59 mL/m² versus 45 mL/m², and a lower average RVEF, at 29% versus 37%.

During follow-up, patients who progressed had a significant increase in RV end-systolic and also end-diastolic volume, whereas these did not change in those who remained stable.

“The absolute differences in RV volumes between stable and progressive PAH patients gradually increased over time which might imply that the changes in RV volumes could be sensitive parameters to monitor patients during follow-up”, write Anton Vonk-Noordegraaf (VU University Medical Center, Amsterdam, the Netherlands) and study co-authors in CHEST.

In addition, RVEF further declined in progressive patients, whereas in stable patients it increased slightly over the first 3 to 4 years and then remained stable.

“We show that in long-term PAH survivors, a clinically stable profile and preserved [cardiac output] may mask RV failure progression, and that changes in RV volumes may be sensitive parameters to predict an ultimate deterioration, even at the time of clinical stability”, say the researchers.

“Our results raise the question whether prognosis can be improved by a goal-oriented strategy using RV rather than clinical parameters as treatment goal.”

They caution, however, that extensive RV remodelling appears to take many years to develop, meaning that their findings “cannot be extrapolated to patients with a more severe hemodynamic profile shortly after the initial diagnosis.”

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