Researchers call for earlier PAH diagnosis and treatment
medwireNews: A study has found that treatment of pulmonary arterial hypertension (PAH) in patients younger than 55 years significantly improves their performance on the 6-minute walk test (6MWT).
By contrast, treatment in older patients was associated with disease stabilisation, and sometimes deterioration. The researchers say the findings highlight the need to treat PAH as early in the disease course as possible.
“This difference in benefit may be the result of more advanced disease at the time of diagnosis with advanced histopathological changes within the pulmonary vasculature affecting the efficacy of available therapy”, comment Nicholas Collins (John Hunter Hospital, New Lambton, New South Wales, Australia) and colleagues.
“This reinforces the need to aggressively investigate dyspnoea to permit appropriately early detection and initiation of therapy.”
The team reviewed 119 patients (88% female) who had been treated with PAH-specific therapies, including endothelin receptor antagonists, phosphodiesterase inhibitors or prostanoids over a maximum follow-up of 8 years. The patients undertook the 6MWT and were given transthoracic echocardiography every 6 months.
The researchers found that in their group of patients, who had a mean age of 65 years, age had a significant effect on the result of the 6MWT, which remained after adjusting for confounders such as smoking, warfarin use and gender. Each year older a patient was at study entry was associated with a 5 metre greater decline in 6MWT distance over the following year.
Further analysis showed that those aged younger than 55 years had a significant improvement in 6MWT distance over time, while the 22 patients aged over 55 years experienced stabilisation or a slight decline in 6MWT distance.
Age at initiation of therapy was also associated with a greater rate of decline in 6MWT over follow-up. However, between each age group over 55 years there was no significant difference compared with baseline.
Writing in Heart, Lung and Circulation, the authors say that the findings may help clinicians to better understand the natural course of PAH with age, which may have implications for making changes, or additions, to therapy. “Decline in 6MWT distance has been used as a tool to identify therapeutic failure and prompt consideration for escalation of treatment”, they explain.
They also note that their findings contradict historical data, showing only a modest decline in function in older patients with treatment and not a dramatic one.
“[O]ur results support the hypothesis that age alone should not be an exclusion to treatment”, they conclude.
By Kirsty Oswald
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