While most veterans with pulmonary hypertension are treated in accordance with clinical guidelines, almost two-thirds who are prescribed therapy are being treated with pulmonary vasodilators inappropriately, an analysis of veteran prescription data reveals.

Little was known about how pulmonary vasodilators were used in practice prior to the publication of this study. While pulmonary vasodilators are considered effective for group 1 pulmonary hypertension (PH), clinical guidelines and advice from the Choosing Wisely campaign recommend against their routine use for PH patients classified into the most common types of PH – groups 2 and 3 – because of a lack of benefit, potential for harm, and high cost, the authors wrote. The report was published in Annals of the American Thoracic Society.

The new analysis shows that patients with PH are potentially being exposed to unnecessary harm, according to study author Renda Soylemez Wiener, MD, MPH, of the Center for Healthcare Organization & Implementation Research at Bedford (Mass.) Veterans Affairs Medical Center, and her colleagues. Their findings also reveal that inappropriate prescribing of pulmonary vasodilators, mostly by specialist clinicians, is contributing to the financial burden of an already stretched health system.

The research team looked at prescription data for veterans prescribed a phosphodiesterase-5 inhibitor (PDE5i), which causes pulmonary vasodilation, between 2005 and 2012 at any VA site. The primary outcome of the study was the proportion of patients who received potentially inappropriate PDE5i as classified in guideline recommendations. Patients with group 1 PH were deemed to have been treated appropriately, while those with group 2 and 3 PH were deemed to have been potentially treated inappropriately. Those with groups 4 and 5 PH were thought to have received treatment of “uncertain value.”

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Among 108,777 veterans with at least one ICD-9CM diagnosis code for PH, 2,790 (2.6% 95% confidence interval, 2.5-2.7%) received daily treatment with PDE5is. Among these, 541 (19.4% [18.0-20.9%]) were being treated appropriately, 1,711 (61.3% [95% CI, 59.5%-63.1%]) were receiving potentially inappropriate treatment, and 358 (12.8% [11.6%-14.1%]) were receiving treatment of uncertain value.

In a chart abstraction analysis from a randomly selected subset of PDE5i-treated patients, half (110/230, 47.8% [41.3%-54.5%]) had documented right heart catheterization to confirm the presence of PH. After factoring this into their algorithm, the investigators determined that only 11.7% [8.0%-16.8%] of these patients received clearly appropriate treatment.

Over the 8-year study period, the number of patients with PH group 2 or 3 prescribed PDE5i rose more than 14-fold, the researchers said. They speculated that this figure was likely to continue to rise with the increasing use of echocardiography and detection of PH.

According to the authors, the cost of treating one PH patient for 1 year with PDE5i therapy was between $10,000 and $13,000.

The 1,711 PH patients classified as being treated inappropriately in the study translated into a cost of over $20 million, if each patient were treated for only 1 year, but many of the patients were treated for a longer period of time.

The researchers suggested that there were several reasons why clinicians might choose to deviate from the guidelines, including lacking familiarity with them or disagreeing with them.

“While guidelines do allow trials of PDE5i in treatment for groups 2 or 3 PH on a case-by-case basis after consultation with a PH expert and a confirmatory [right heart catheterization], even PH experts disagree about whether a trial of PDE5i therapy is reasonable and appropriate for patients with group 3 PH,” they wrote.

They may also overestimate the potential benefits of treatment and/or underestimate potential harm.

Clinicians may believe that guidelines developed for a general population do not apply to the patients they are treating.

“It is understandable why clinicians may offer unproven therapies like PDE5i in hopes of providing relief to very sick patients with groups 2 or 3 PH, especially if they do not believe the recommendation applies to their individual patient or they are not convinced about the potential harms of pulmonary vasodilators,” they said.

The authors expressed concern about VA clinicians’ allowing patients to take PDE5i therapy that had been initially prescribed by clinicians outside of VA hospitals. The researchers said such drugs, which potentially had been prescribed inappropriately, “were continued by VA clinicians without much apparent scrutiny.”

The chart abstraction analysis also showed that specialists prescribed the majority of potentially inappropriate PDE5i treatment, suggesting “that other interventions to prevent inappropriate use may be required.”

The researchers concluded that “[the] time has come to develop interventions to optimize prescribing for PH in order to improve the value, quality, and safety of care.”

One potential intervention suggested by the researchers was to require patients with PH to be evaluated at a PH expert center, as recommended by treatment guidelines.

The study was funded by the Department of Veterans Affairs with resources from the Edith Nourse Rogers Memorial VA Hospital. Elizabeth S. Klings, MD, one of the study’s authors, declared receiving research support from several pharmaceutical companies.

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SOURCE: Wiener RS et al. Ann Am Thorac Soc. 2018 Feb 27. doi: 10.1513/AnnalsATS.201710-762OC.

Phosphodiesterase-5 inhibitors often prescribed inappropriately