This news release claims that a two-tiered “hybrid” approach to scanning people with suspected coronary artery disease is superior to assessing such patients with an imaging procedure called coronary angiography.
With coronary angiograms, dye is injected into the arteries and then imaged with an x-ray machine to show areas of narrowing in coronary blood vessels. The hybrid approach described here, based on a published study, involves the combination of two other imaging techniques — coronary computed tomography angiography (CCTA) and single photon emission tomography (SPECT) — to produce what the release says is a more accurate picture of cardiac blood flow. That information can supposedly help identify which patients need coronary artery interventions like angioplasty and bypass surgery.
While the release does a nice job explaining the science behind the hybrid approach and the rationale for its use, there is a mismatch between the overstated headline and the more accurate language featured in the release’s conclusion. The headline describes the hybrid approach as an “effective tool” for evaluating coronary artery disease; the last paragraph acknowledges that the approach hasn’t been tested in a clinical trial and that we don’t know if it actually has a positive impact on patient outcomes.
The lack of any clear patient benefit shouldn’t be treated like an afterthought.
The human body and its tissues can be scanned in all manner of ways involving lots of different devices. Such scans can provide information that wouldn’t otherwise have been known and which may appear to be useful for preventing or treating disease. But what seems like useful information may not always have value for patients — it might lead to aggressive and unnecessary treatment that doesn’t improve the outcomes that people care about.
That’s why it’s important to test new technology in ways that can measure real patient benefits like longer life and better quality of life. And it’s why writers should refrain making claims of effectiveness until such benefits have been credibly demonstrated.
There is no discussion of the cost of the hybrid imaging approach compared with the standard approach.
The news release does a reasonable job of quantifying what the researchers found in the study — namely that the hybrid imaging identified some patients who would go on to suffer major cardiac events. Here’s the description:
Patients with matched findings–stenosis of 50 percent or more on CCTA with evidence of ischemia on SPECT in the area of the heart to which the blocked vessel was supplying blood–had more than five times the risk of adverse events than those with normal findings. Patients with unmatched findings, or evidence of ischemia but not in the area of the heart being fed by the stenotic artery, had three times the risk. Major adverse cardiac event rates were 21.8 percent for matched findings and 9.0 percent for unmatched–considerably higher than the 2.4 percent rate for normal findings.
What’s missing, however, is any comparison of how these numbers stack up against results with the standard approach — a coronary angiogram. Such a comparison is necessary to support the news release’s contention that the hybrid approach is superior.
The news release doesn’t address harms, which at a minimum involve exposure to an additional radiation-based imaging technique that could increase the risk for cancer.
The news release headline claims hybrid imaging is an “effective tool” for predicting heart attacks. But it doesn’t say how the results obtained in the study compare to standard imaging practices for patients with suspected cardiovascular disease. Moreover, it’s not until the final paragraph that we learn that the hybrid approach is still in the preliminary stages of testing, and researchers still don’t know if hybrid imaging will have a positive impact on patient outcomes. For the tool to be “effective,” we need to know whether it actually makes a difference in how patients are treated and whether it improves their outcomes.
There is no disease mongering. The release states that “Coronary artery disease is a leading cause of death and disability worldwide,” which is accurate.
The study’s first author disclosed that he is on the speaker’s bureau for GE Healthcare, which manufactures the nuclear imaging machines discussed in the news release. Although the author claims that this relationship is not relevant to the current study, we don’t see how that can be accurate. If the author has a financial relationship with a company that stands to benefit from the approach advocated in the study, that certainly seems relevant to disclose and the news release should have done so.
The news release is clear that the study is testing an alternative to the standard approach for evaluating cardiovasular risk in patients with suspected coronary artery disease.
It’s not clear how widely available the hybrid approach is. Given that the hybrid approach is really just a combination of two existing tests (a CT scan and a nuclear scan) it stands to reason that it should be available in most medical centers but the release fails to explain this.
The point of the study, according to the news release, is to determine whether the hybrid approach is useful for predicting long-term cardiac outcomes.
The news release skirts the line when it makes the following recommendation:
The study supports CCTA use for an initial, noninvasive evaluation of patients with known or suspected stable coronary artery disease. No additional imaging would be necessary if the results were normal. If a lesion was evident, then clinicians could employ a nuclear scan to assess ischemia and take advantage of both modalities by fusing the results together to make a hybrid image.
There’s no evidence provided in the news release or the study to back up the claim that this proposed two-step approach is more effective than the current practice.
However, this statement is not quite egregious enough to merit a Not Satisfactory rating here, which we typically reserve for over-the-top claims of “breakthroughs” and “game changers”.