Stress Echo in Asymptomatic Patients After Revascularization 'Not Worth It'

Marlene Busko

June 26, 2012

May 14, 2012 (Cleveland, Ohio) — A large observational study suggests that routine, periodic stress echocardiography testing in asymptomatic patients who have undergone PCI or CABG is costly and "probably not worth the effort," experts say.

Exercise capacity and clinical-test findings rather than echo findings were better predictors of mortality [1]. Repeat revascularization, even in the high-risk patients, did not lead to better mortality outcomes.

"The specific scenario relates to asymptomatic patients who have had a stent or CABG and they or their doctor say(s), 'I wonder if that CAD is coming back; maybe we should do a test to identify it before it becomes a problem,' " Dr Serge Harb (Cleveland Clinic Heart and Vascular Institute, OH) explained to heartwire . "In this setting, exercise capacity and stress echo are predictors of outcome, but we find that outcome seems uninfluenced by repeat revascularization. . . . The clinical implications are that this activity is a waste of time," he added.

The study is published online May 14, 2012 in the Archives of Internal Medicine as part of the "Less is More" series.

Does Exercise Testing Improve Outcomes?

"The [guideline] criteria claim that testing asymptomatic patients more than two years after PCI and more than five years after CABG are appropriate," Harb noted. "This is based on prognostic data, but nobody has 'closed the loop' to see whether the [testing] changes outcomes."

They performed a study of 2105 patients who had undergone PCI (54% of patients) or CABG (46%) and had no symptoms when they were referred for a treadmill exercise echo test from 2000 to 2010. The patients had a mean age of 64 years, and 15% were women. They had undergone revascularization 4.1 years earlier, on average. The primary study outcomes were repeat revascularization within six months of the stress echo and cardiac and all-cause mortality during a mean follow-up of 5.7 years.

The stress echo test identified ischemia, defined as new or worsening wall-motion abnormality, in 262 patients (13%). Of these patients, only 88 patients (34%) underwent repeat revascularization.

Patients who had ischemia--identified either in early testing (less than two years after PCI or less than five years after CABG) or late testing--were more likely to die during follow-up. However, clinical findings and exercise capacity were better than echocardiographic features in predicting survival.

Asked to speculate why repeat revascularization did not improve outcomes, Harb said: "I think it's a couple of things. First, the presence of ischemia doesn't necessarily mean that a suitable vessel is present for revascularization. Second, things other than ischemia (heart failure, low ejection fraction, etc) may be stronger determinants."

Commentary, Editorial Note Also See No Added Value

"Until well-supported data become available [backing up] such a strategy, routine testing in asymptomatic patients is probably not worth the effort," Dr Mark Eisenberg (McGill University, Montreal, QC) writes in an accompanying invited commentary [2].

"The study suggests that routine periodic treadmill tests with or without nuclear or echo imaging--in short, any type of routine functional test in an asymptomatic patient without a clear clinical indication--[is of little clinical benefit] . . . although in the US, many doctors are doing it for medicolegal reasons or their patients are asking for it," he commented to heartwire .

In an editor's note [3], Dr Rita Redberg (University of California, San Francisco) writes that "Do not perform serial stress cardiac imaging or advanced noninvasive imaging as part of routine follow-up in asymptomatic patients" is one of the "top five" recommendations for an activity that if not done would result in better patient outcomes that were identified by the American College of Cardiology. Performing routine, repeat stress echo tests on these asymptomatic patients "can result in additional procedures that can cause harm but do not lead to reduced mortality," she notes.

The authors have no disclosures. Eisenberg is a national investigator of the Quebec Fund for Health Research.


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