CHICAGO – A stepwise care pathway was associated with a substantial reduction in the number of invasive tests performed and a major improvement in outcomes, relative to usual management, in patients suspected of coronary artery disease (CAD), according to 1-year results of the multinational, randomized PRECISE trial.
The care pathway is appropriate for patients with nonacute chest pain or equivalent complaints that have raised suspicion of CAD, and it is extremely simple, according to the description from the principal investigator, Pamela S. Douglas, MD, given in her presentation at the annual scientific sessions of the American Heart Association.
Unlike the highly complex diagnostic algorithms shunting suspected CAD patients to the vast array of potential evaluations, the newly tested protocol, characterized as a “precision strategy,” divides patients into those who are immediate candidates for invasive testing and those who are not. The discriminator is the PROMISE minimal risk assessment score, a tool already validated.
Those deemed candidates for testing on the basis of an elevated score undergo computed coronary CT angiography (cCTA). In those who are not, testing is deferred.
Strategy is simple but effective
Although simple, this pathway is highly effective, judging by the results of the PRECISE trial, which tested the strategy in 2,103 patients at 65 sites in North America and Europe. The primary outcome was a composite of major adverse cardiovascular events (MACE) that included death, nonfatal MI, and catheterization without observed CAD.
After a median follow-up of 11.8 months, the primary MACE endpoint was reached in about 11.3% of those in the usual-care group, which was more than twofold higher than the 4.2% in the precision strategy group. The unadjusted risk reduction was 65% but rose to more than 70% (hazard ratio, 0.29; P < .001) after adjustment for gender and baseline characteristics.
In the arm randomized to the precision strategy, 16% were characterized as low risk and received no further testing. Almost all the others underwent cCTA alone (48%) or cCTA with fractional flow reserve (FFR) (31%). Stress echocardiography, treadmill electrocardiography, and other functional studies were performed in the small proportion of remaining patients.
cCTA performed in just 15% of usual care
In the usual-care arm, cCTA with or without FFR was only performed in 15%. More than 80% of patients underwent evaluations with one or more of an array of functional tests. For example, one-third were evaluated with single photon emission CT/PET and nearly as many underwent stress echocardiography testing. Only 7% in usual care underwent no testing after referral.
Within the MACE composite endpoint, almost all the relative benefit in the precision strategy arm was derived from the endpoint of angiography performed without evidence of obstructive CAD (2.6% vs. 10.2%). Rates of all-cause mortality and MI were not significantly different.
Important for the safety and utility of the precision strategy, there “were no deaths or MI events among those assigned deferred testing ” in that experimental arm, according to Dr. Douglas, professor of research in cardiovascular diseases at Duke University, Durham, N.C.
Instead, those in the precision strategy arm were far less likely to undergo catheterization without finding CAD (20% vs. 60%) and far less likely to undergo catheterization without revascularization (28% vs. 70%).
In addition, the group randomized to the precision strategy were more likely to be placed on risk reducing therapies following testing. Although the higher proportion of patients placed on antihypertensive therapy did not reach statistical significance (P = .1), the increased proportions placed on lipid therapy (P < .001) and antiplatelet therapy (P < .001) did.
Citing a study inthat found that more than 25% of patients presenting with stable chest pain have normal coronary arteries, Dr. Douglas said that the precision strategy as shown in the PRECISE trial addresses several agreed-upon goals in guidelines from the AHA, the European Society of Cardiology and the U.K.’s National Institute for Health and Care Excellence. These goals include reducing unnecessary testing by risk stratification, improving diagnostic yield of the testing that is performed, and avoiding the costs and complications of unneeded invasive testing.