Doctors, Risk Tools Often at Odds When Assessing Risks in Patients With A-fib Undergoing PCI

SAN DIEGO, CA - When it comes to gauging the risks of ischemic and bleeding events in patients with nonvalvular A-fib who are undergoing PCI, subjective assessments by physicians often don’t match up with more objective tools, findings from the AVIATOR 2 registry show.

Physicians’ impressions were close to empiric estimates when risk was in the intermediate range, but doctors tended to overestimate risk in lower-risk patients and underestimate risk in higher-risk patients, especially when looking at CHA2DS2-VASc scores, Usman Baber, MD (Icahn School of Medicine at Mount Sinai, New York, NY), is reporting today at the Society for Cardiovascular Angiography and Interventions 2018 Scientific Sessions in San Diego, CA.

“Ultimately, this suggests that we tend to overtreat low-risk patients and vice versa among higher-risk individuals,” he said at a press conference.

Other interesting observations to come out of the registry, he said, were that use of oral anticoagulation seemed to be driven more by objective assessments of ischemic—as opposed to bleeding—risks and that patients were less concerned than physicians with major bleeding when it came to use of antithrombotic therapy.

“The clinical imperatives—namely, what the clinicians place as most important surrounding antithrombotic therapy—are not completely aligned with patient concerns,” Baber said.

Patients will continue to be followed for up to 1 year after PCI, and Roxana Mehran, MD (Icahn School of Medicine at Mount Sinai), principal investigator of the registry, told TCTMD that information on event rates during that time will provide important information about which baseline assessments—by physicians, patients, or objective tools—are most closely aligned with actual risk.

It could be that physicians are better than objective tools at identifying risks, she said, adding that the fact that concerns among doctors and their patients are not completely in sync highlights the importance of listening to the patients’ perspectives.

“It’s all the more reason to bring the patient into the equation,” Mehran said. “I think we have to listen more to what our patients care about, make sure that we have endpoints that are important to them as well as to us.”

I think we have to listen more to what our patients care about, make sure that we have endpoints that are important to them as well as to us. Roxana Mehran

The prospective AVIATOR 2 registry was designed to evaluate several questions related to use of antithrombotic therapy in patients with A-fib undergoing PCI, a particularly tricky group with indications both for oral anticoagulation and dual antiplatelet therapy (DAPT). A novel aspect of the study is that it employed a smartphone app at the time of PCI to collect information from both physicians and patients about what factors regarding treatment were most important to them.

The study ultimately enrolled 514 patients at 11 centers in the United States and Europe between June 2015 and November 2017, falling well short of the originally planned 2,500 patients because funding ran out. That means, according to Mehran, that the study will be underpowered for its primary endpoint, MACCE at 1 year. Those results will likely by presented next year.

Choice of antithrombotic therapy was left up to the discretion of the treating physicians, and about two-thirds of patients were discharged on triple therapy combining oral anticoagulation and DAPT. Another 20% received dual therapy with an oral anticoagulant and a P2Y12 inhibitor, and 14% received DAPT alone. The P2Y12 inhibitor was clopidogrel in the vast majority of cases (93%), with minimal use of ticagrelor (Brilinta; AstraZeneca) and prasugrel (Effient; Eli Lilly).

When doctors were asked to select the two factors most important in choosing medications, they chose safety (93.8%) and efficacy (89.9%). Other factors like familiarity, availability, frequency, and cost were highlighted by only a small proportion.

Those choices are not completely consistent with what patients were most worried about. Major bleeding was selected as primary concern by only 14.8% of patients, who were mostly worried about having a heart attack (63.4%) or stroke (50.6%) or about dying (47.5%).

In addition to showing that physicians’ risk assessments often were not consistent with scores for risks of ischemic events (CHA2DS2-VASc) or bleeding (HAS-BLED), the registry also revealed that inclusion of oral anticoagulation in the treatment regimen was more strongly related to objective assessment of ischemic risk.

Ultimately, though, tallying actual events will be key to determining what all of this means in terms of the impact on clinical outcomes, Mehran said. “What’s very important is this longitudinal follow-up. That will actually show us some more insights into correlations of risk and events.”

Note: Mehran and study co-author George Dangas, MD, PhD, are faculty members of the Cardiovascular Research Foundation, the publisher of TCTMD.