Deferred testing for low-risk chest pain patients is safe, limits unnecessary catheterizations

Among patients who had their testing deferred, 64% never underwent testing over the study’s follow-up period of one year. The remaining 36% eventually underwent downstream testing after a median time period of 48 days “based on ongoing or worsening symptoms.” Results were completely normal for 96% of patients when they did undergo testing.

For patients who underwent usual testing, meanwhile, the most common modalities were functional stress tests (83%) and coronary angiography (3%). Another 13% ultimately ended up not undergoing any tests for their chest pain during the follow-up period.

The study’s primary endpoint, a composite of all-cause death, nonfatal myocardial infarction (MI) and catheterization without obstructive CAD, was seen in 0.9% patients in the deferred group and 6.3% of patients in the usual testing group. No deferred patients experienced death or a nonfatal MI. One noncardiovascular death and one MI were seen in the group that was tested like normal. The biggest difference between the two groups was the fact that 0.9% of patients in the deferred group underwent catheterizations without obstructive CAD compared to 5.8% in the usual testing group.

“In symptomatic people with suspected CAD, identification of individuals at minimal risk for obstructive CAD and outcome events by the PMRS enabled a strategy of initial deferred testing with patient consent,” the authors wrote. “In this trial, the strategy was safe with no observed adverse outcome events, fewer invasive catheterizations without significant CAD, and fewer low-yield noninvasive tests compared with a usual testing strategy. Symptoms diminished over time to a similar degree as the alternative strategy of initial functional testing or catheterization.”

These findings, the team added, “support existing guideline recommendations” related to deferred diagnostic testing.

“Implementation of this approach has the potential to safely reduce very low-yield testing and improve care and the efficiency of testing for suspected CAD,” the authors concluded.