Clinical tool can reduce the use of CPTA in cancer patients

A bedside clinical decision tool can rule out pulmonary embolism in cancer patients as safely as CT pulmonary angiography (CTPA), according to a study published July 12 in JAMA. 

In the six-country trial of 698 patients with active cancer and suspected pulmonary embolism (PE), use of the YEARS algorithm obviated the need to perform CTPAs in 22% of patients without increasing the risk of a missed blood clot, noted lead author Bram Akerboom, MD, of Leiden University Medical Center in the Netherlands, and colleagues. 

"The YEARS algorithm is as safe as a CTPA-only approach to exclude PE in patients with active cancer and avoids CTPA scans," the authors wrote. 

PE is about 11 times more common in people with cancer than in the general population, and cancer patients often undergo several CT scans over the course of treatment, the authors explained. The YEARS algorithm is a validated tool developed in 2017 to help safely exclude PE without CPTA. The algorithm assesses PE probability based on three clinical items combined with a D-dimer blood test. If the D-dimer level is below a certain threshold, acute PE can be safely ruled out; if it exceeds the threshold, CTPA is performed. 

While the YEARS algorithm is a safe and efficient way to rule out acute PE, robust evidence on its accuracy in patients with cancer is lacking, and hence the researchers launched a randomized noninferiority trial to evaluate whether the YEARS algorithm is as safe as and more efficient for ruling out PE in these patients. 

The researchers randomly assigned 698 patients with active cancer and suspected pulmonary embolism across 21 hospitals in the Netherlands, Italy, Switzerland, Belgium, France, and Spain to either diagnostic management with either the YEARS algorithm or CTPA alone. The primary outcome was symptomatic venous thromboembolism or PE-related death within 90 days after ruling out PE at baseline. 

Blood clots or possible clot-related deaths occurred in 1.8% of patients managed with the YEARS algorithm versus 5.5% of those who received CTPA alone, a risk difference of -3.7 percentage points that fell within the study's preset margin for declaring the algorithm noninferior, the researchers reported. 

In addition, diagnostic management of PE was carried out for 77 of 352 patients (22%) in the YEARS group without CTPA, and no difference in the proportion of negative CTPA (P = .93) was observed between the groups, according to the findings. 

“Implementing the YEARS algorithm for PE diagnosis in these patients not only will reduce health care costs and the growing workload for radiology departments but will also result in patients spending less time in the hospital, undergoing less radiation, and experiencing less exposure to contrast material,” the authors wrote. 

In an accompanying editorial, Henry Han, MD, and Joshua Beckman, MD, both of the University of Texas Southwestern Medical Center in Dallas, wrote that the study’s sample size did not permit analysis by cancer site or stage, so that the performance of the YEARS algorithm in highly thrombogenic tumors such as pancreatic, gastric, and brain cancer remains undefined. 

Nonetheless, the results establishes that CTPA for all, while safe, is not the only reasonable approach, they wrote. 

“The next studies should ask not whether decision rules apply to this population but how to refine them for the heterogeneous biology of cancer-associated thrombosis,” Han and Beckman wrote. 

The full study is available here.