Cardiac magnetic resonance imaging associated with optical coherence tomography (OCT) in women who presented with myocardial infarction (MI) with non-obstructive coronary arteries (MINOCA) on angiography identified potential mechanisms of injury in nearly 85% of women, according to the results of the HARP study.
In the prospective, multicentre, international, observational study of over 300 women with a diagnosis of MINOCA, multimodal imaging found possible mechanisms in 84.5%, with three-quarters ischemic and one-fourth non-ischemic, alternative diagnoses to MI, reported . Harmony R. Reynolds, MD, of the Sarah Ross Soter Center for Women’s Cardiovascular Research at NYU Langone Health in New York City, at the American Heart Association (AHA) virtual meeting. The study results were published simultaneously in Circulation.
Reynolds also reported that of the 116 women in the study who underwent multimodal imaging, a cause was determined in 98:
- 64% MI
- 15% myocarditis
- 3% Takotsubo syndrome
- 3% non-ischemic cardiomyopathy
- 15% no cause identified
“Identifying the etiology of MINOCA is feasible and has the potential to guide medical therapy for secondary prevention,” Reynolds and colleagues wrote.
However, he warned that “Not all forms of imaging tests are available in all medical centers. Coronary OCT” is not currently available in most centers where heart attack patients are taken, but is available at specialized centers. In time, I anticipate coronary OCT could be more widely used as a routine care for MINOCA patients. “
And “These tests add cost,” Reynolds said MedPage todaybut noted that “it is important to have a diagnosis for the patient as it has cascading implications for treatment.”
At an AHA press conference, Reynolds said the findings were important “because women with MINOCA have historically been told that because the angiogram is okay, they have never had a heart attack. This is totally wrong for you. about two-thirds of the women who had both imaging tests and misleading for a quarter of the women because we found they had another problem that was not related to blood flow and could be diagnosed by cardiac MRI. “
“One in 10 heart attacks in women is MINOCA – three times the number that occurs in men,” he said. “In the 4 years after MINOCA, the risk of a major cardiovascular event is 24%. The risk of death within 5 years of the event is 11%.”
For the HARP study, Reynolds and colleagues enrolled 301 women (mean age 60 years; 50% white non-Hispanic) with a clinical diagnosis of MI. Of these, 170 were diagnosed with MINOCA and 145 had OCT image quality adequate for analysis, while 116 of these patients underwent cardiac MRI.
“If invasive coronary angiography revealed <50% stenosis in all major arteries, multi-vessel OCT was performed, followed by CMR ... Angiography, OCT and CMR were evaluated in blinded independent laboratories. The culprit lesions identified by OCT were classified as definite or possible. The central CMR laboratory identified ischemic-related and non-ischemic myocardium, "the authors explained.
Whenever possible, imaging results were combined to pinpoint the mechanism of MINOCA, they added.
The authors reported that a definite or possible culprit injury was identified by OCT in 46.2% of participants, most commonly plaque rupture, intraplaque cavity, or layered plaque. CMR was abnormal in 74.1% of the participants and an ischemic pattern of CMR abnormalities (heart attack or myocardial edema in a coronary territory) was present in 53.4%.
Limitations of the study included the relatively small sample size, few patients with ST-segment elevation MI, and the fact that the three-vessel OCT was incomplete in some cases, which may have led to underestimation of the prevalence of the culprit lesion. the authors explained.
AHA discussant Martha Gulati, MD, of the University of Arizona / Banner University Medical Center in Phoenix, said, “MINOCA occurs in up to 15 percent of heart attacks, especially in women. Understanding the cause of MINOCA there. will help treat these patients appropriately. Lack of obstruction does not mean that the heart attack is benign. “
However, Gulati said the lack of male participants hindered generalization. Future studies should look at ways to optimally treat MINOCA, with an eye on improving outcomes, he added.
The HARP study was funded by the American Heart Association Go Red for Women Strategically Focused Research Network, the National Center for Advancing Translational Sciences, and the NIH.
Reynolds disclosed relevant relationships with Abbott Vascular, Siemens and BioTelemetry. The co-authors revealed multiple relevant relationships with the industry.
Gulati did not disclose relevant relationships with the industry.