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ESC: CTA for Stable Chest Pain Prevents More MIs Long Term

— Better than stress ECG as first-line test, SCOT-HEART investigators say

Last Updated August 27, 2018
Ƶ MedicalToday

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MUNICH -- Patients who underwent coronary CT angiography (CTA) to diagnose their chest pain ended up with more preventive therapies and had better outcomes in the long run, according to the SCOT-HEART trial that compared them to a standard-of-care group that predominantly received stress ECG evaluation.

The CTA group had fewer deaths from coronary heart disease and non-fatal MIs at 5 years (2.3% vs 3.9% for standard of care, HR 0.59, 95% CI 0.41-0.84), a finding that was largely driven by the reduction in MI (2.1% vs 3.5%, HR 0.60, 95% CI 0.41-0.87). No differences in death from coronary heart disease or any cause were observed between study arms.

Of note, recipients of CTA had more invasive coronary angiography and coronary revascularization done in the first few months, but this was no longer true at 5 years, said David Newby, MD, of the University of Edinburgh in Scotland, and colleagues.

The results were presented at a late-breaking trial session at the European Society of Cardiology (ESC) meeting here and simultaneously published in the .

David Newby, MD

David Newby, MD, presenting the results at ESC

CTA was associated with more patients getting started on preventive therapies (19.4% vs 14.7%, OR 1.40, 95% CI 1.19-1.65) and antianginal therapies (13.2% vs 10.7%, OR 1.27, 95% CI 1.05-1.54).

"Our findings suggest that the use of CT angiography resulted in more correct diagnoses of coronary heart disease than standard care alone, which, in turn, led to the use of appropriate therapies, and this change in management resulted in fewer clinical events in the CT angiography group than in the standard-care group," Newby's group stated.

The two groups shared similar event rates until diagnoses were confirmed and treatments altered after approximately 7 weeks, the authors noted.

SCOT-HEART trialists previously reported results out to 20-22 months showing that CTA clarified the diagnosis and altered subsequent investigations and treatments among patients with suspected coronary artery disease.

The problem with the hypothesis that better uptake of preventive therapies led to fewer MIs in the CTA arm is that the difference in medical management between the groups was actually quite modest, according to Udo Hoffmann, MD, MPH, of Massachusetts General Hospital, and James Udelson, MD, of Tufts Medical Center, both in Boston.

The difference isn't enough to explain the much lower rate of MI in the CTA group, they said in an , arguing that the key is instead the "suboptimal"strategy of stress ECG testing being the main standard of care (85% of cases).

Hoffmann and Udelson recalled the PROMISE trial, which showed in 2015 that CTA was not associated with better outcomes than functional testing in patients with suspected coronary disease. The caveat: only 10% got stress ECG tests in the functional testing arm back then.

"The more general message from these trials is that the information provided by a diagnostic test can resonate therapeutically beyond making a correct diagnosis of coronary artery disease and that clinicians should aggressively pursue preventive measures to achieve the best outcomes possible while minimizing daily symptoms," they stated.

SCOT-HEART was conducted across 12 centers in Scotland. Participants were adults with stable chest pain (n=4,146) who were randomized to standard care with or without coronary CTA.

Investigators had a median 4.8 years of follow-up for the analysis.

They cautioned that this was a open-label trial that left room for some bias, and that they didn't have the information to account for lifestyle alterations that might have occurred among patients.

Even so, CTA is "clearly" a better first-line test than stress ECG, Udelson said in an interview.

Since 2016, the U.K. National Institute for Health and Care Excellence guidelines have listed CTA as the for chest pain due to suspected coronary artery disease.

Guidelines from the U.S. haven't been updated since 2014, when several tests were said to be appropriate to use and CTA received a rating for low-risk populations that can exercise.

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    Nicole Lou is a reporter for Ƶ, where she covers cardiology news and other developments in medicine.

Disclosures

Newby disclosed support from Siemens.

Hoffmann and Udelson disclosed relevant relationships with HeartFlow.

Primary Source

New England Journal of Medicine

Newby DE, et al "Coronary CT angiography and 5-year risk of myocardial infarction: The SCOT-HEART investigators" N Engl J Med 2018; DOI: 10.1056/NEJMoa1805971.

Secondary Source

New England Journal of Medicine

Hoffmann U, Udelson JE "Imaging coronary anatomy and reducing myocardial infarction" N Engl J Med 2018; DOI: 10.1056/NEJMe1809203.