– The recommended approach to evaluating suspected pulmonary embolism is “greatly underutilized” in the Veterans Health Administration system, Nancy Hsu, MD, said at the annual meeting of the American College of Chest Physicians.

Dr. Nancy Hsu of the VA Greater Los Angeles Healthcare System Andrew Bowser/MDedge News

Dr. Nancy Hsu

Most Veterans Affairs sites did not require incorporation of a clinical decision rule (CDR) and highly sensitive D-dimer prior to ordering CT pulmonary angiography (CTPA) for suspected pulmonary embolism (PE), according to results of a survey by Dr. Hsu and her coinvestigator, Guy Soo Hoo, MD.

While CTPA has become the imaging modality of choice for evaluating suspected PE, it is overused and potentially avoidable in one-third of cases, said Dr. Hsu, who is with the VA Greater Los Angeles Healthcare System.

“In the 10 years following the advent of CTPA use, there was a 14-fold increase in usage, but there was no change in mortality,” Dr. Hsu said. “This is consistent with overdiagnosis.”

Indiscriminate use of CTPA results in unnecessary and avoidable radiation exposure, contrast-related reactions, and treatment-related bleeding, Dr. Hsu said.

Dr. Hsu and Dr. Soo Hoo surveyed 606 individuals at 18 Veterans Integrated Service Networks (VISNs) and 143 medical centers. A total of 120 fully completed questionnaires were analyzed.

Most respondents (63%) were chiefs, and 80% had 11+ years of experience, Dr. Hsu reported.

Almost all respondents (85%) said CDR with or without D-dimer was not required before ordering a CTPA, survey results show, while only about 7% required both.

“A very small minority of [Veterans Integrated Service Networks], or geographic regions, contained even one hospital that adhered to the guidelines,” Dr. Hsu added.

Though further analysis was limited by sample size, the average CTPA yield for PE appeared to be higher when both components were used in the evaluation, according to Dr. Hsu, who noted an 11.9% yield for CDR plus D-dimer.

Use of CTPA appeared lower at sites with CDR and D-dimer testing, Dr. Hsu added.

These results suggest a need for further research to compare CTPA use and yield in sites that have the algorithm in place, Dr. Hsu told attendees at the meeting.

Adherence to the CDR plus D-dimer diagnostic strategy is “modest at best” despite being a Top 5 Choosing Wisely recommendation in pulmonary medicine, Dr. Hsu told attendees.

The biggest barrier to optimal practice may be the fear of having a patient who “falls through the cracks” based on false-negative CDR and D-dimer data, according to Dr. Hsu.

On the other hand, judicious use of CTPA likely avoids negative sequelae related to radiation, contrast exposure, and treatment-related bleeding, Dr. Hsu said.

“It’s all about balancing risks and benefits,” she said from the podium in a discussion of the study results.

Dr. Hsu and Dr. Soo Hoo disclosed that they had no relationships relevant to their research.

SOURCE: Hsu N et al. CHEST. 2018 Oct. doi: 10.1016/j.chest.2018.08.937