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AHA Was Without 'Blockbuster' Trials, But Still Worth It

Op-Med is a collection of original articles contributed by Doximity members.

The just-concluded AHA meeting was a noble effort to provide science, discussion and advancement of care. Congratulations to the leaders for providing information and discussion in complex circumstances. 

From an interventional perspective, this year’s meeting lacked the high-profile trial results such as the ISCHEMIA Trial in 2019. However, one might consider this meeting as an opportunity for science to “catch up" for interventional cardiology. The focus was on how we optimize diagnoses and treatment. I will focus on three trials presented which emphasize this optimization of management strategies. 

The first is Coronary OCT and Cardiac MRI to Determine Underlying Causes of MINOCA in Women - HARP-MINOCA, (1) a cleverly designed study to assess vascular changes in female patients taken to the catheterization lab for acute PCI in the setting of suspected myocardial infarction (MI) but who in fact had lesions <50% in severity. These patients underwent three vessel Ocular Coherence Tomography (OCT) to better understand the underlying vascular pathology. The study enrolled 301 women from 16 sites with suspected MI of whom 170 had MINOCA (no significant lesion). A total of 25 were eliminated for technical reasons, with 145 undergoing OCT. The mean age was 60, with 50% of patients being non-white, with hypertension in 46% and diabetes in 16%. Mean peak troponin was 17 times the upper limit of normal with angiographic assessment showing maximal stenosis of 30% (26-37%) in patients of whom 44% had abnormal echo segmental wall motion abnormalities. Importantly, OCT identified a culprit lesion in 46% of patients most commonly via characteristics of a ruptured or “active” plaque, consistent with atherosclerotic pathophysiology of infarction although not low limiting. All patients underwent Cardiac Magnetic Resonance (CMR) Imaging to assess myocardial damage. The results showed that more than half of patients had defects consistent with myocardial damage or infarction. Importantly, there was correlation between OCT and CMR imaging in 69% of cases, suggesting that the culprit lesion correlated to the site of injury. Overall, 44% of patients were identified as not having an atherosclerotic case suggesting spasm, thromboembolism and or a missed culprit lesion. The findings support the importance of treating women with MINOCA for atherosclerotic risk factors as an important adjunct to treatment. Practically, the HAPR-MINOCA study emphasized the importance of optimally using imaging tools to identify mechanisms related to better understanding pathophysiology of disease events.  

A second trial, ALPHEUS (Assessment of Loading With the P2Y12 Inhibitor Ticagrelor or Clopidogrel to Halt Ischemic Events in Patients Undergoing Elective Coronary Stenting) (2) was a PCI trial designed to assess the efficacy of loading of clopidogrel vs. ticagrelor for patients undergoing planned PCI. Traditionally, many practitioners have believed there were advantages to ticagrelor. Patients randomized included 1,910 with 30-day follow-up for an acute comparison, which would likely be most important in this stable anginal cohort. In addition, at least one of many high-risk factors must be present in each patient such as complex procedure, age greater than 75, etc. The results showed that the primary endpoint was not different between the two treatment groups for stent thrombosis with myocardial infarction or major MI at 48 hours occurring in 36.2% of clopidogrel patients and 35.5% of ticagrelor patients (p=0.75). These results support the use of clopidogrel for routine PCI treatment of stable angina patients.

The third trial, RAPID-CTCA: Early Coronary CT Angiography in Patients With Suspected or Provisionally Diagnosed Acute Coronary Syndrome - RAPID CTCA, (3) compared early cardiac computed tomography angiography (CTCA) to usual care in patients presenting to a hospital with suspected acute coronary syndrome. There were 1,748 patients randomized to CTCA versus usual care, with the results showing no difference in all-cause death or MI, including stent thrombosis at one year with a primary event occurring in 6.1% of the usual care group and 5.8% of the CTCA patients (p=0.65). Thus, use of CTCA did not improve clinical outcomes and was associated with a modest increase in hospital cost and length of stay. 

In summary, as always there are winners and losers and while not blockbuster trials, we learned some important management lessons from the trials presented.

References:

1. Reynolds HR. Coronary optical coherence tomography and cardiac magnetic resonance

imaging to determine underlying causes of MINOCA in women. Circulation. 2020;Epub ahead of print.

2. Silvain J, Lattuca B, Beygui F, et al., on behalf of the ALPHEUS Investigators. Ticagrelor versus                 clopidogrel in elective percutaneous coronary intervention (ALPHEUS): a randomized, open-label, phase 3b trial. Lancet 2020;Nov 14:[Epub ahead of print].

3. Presented by Dr. Alastair J. Gray at the American Heart Association Scientific Sessions, 2020.

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