Samit Shah, MD, PhD, assistant professor of medicine (cardiovascular medicine), and Alexandra Lansky, MD, professor of medicine (cardiovascular medicine), recently published a new, open-access article in the Journal of the Society for Cardiovascular Angiography & Interventions (JSCAI) outlining their protocol for the DISCOVER INOCA Registry, a prospective, multicenter study on patients with INOCA (ischemia and non-obstructive coronary arteries).
INOCA is most common in women and includes disorders such as coronary microvascular dysfunction, vasospastic angina, myocardial bridging, and endothelial dysfunction.
In an interview, Shah discusses heart disease in women, guideline-recommend protocols for diagnosing the disease, and how providers can support patients with a proper diagnosis.
1. What led you to study INOCA?
The field of medicine is still behind in our understanding of how cardiovascular disease occurs in women. For example, when women present with chest pain and shortness of breath in the emergency department, they wait longer to be seen than men, are less likely to have an EKG performed, and are less likely to be prescribed cardiac medications. We have a lot of work to do to improve how we diagnose and treat cardiovascular conditions in women, and we hope the DISCOVER INOCA Registry will help us do that.
2. Tell me about your study design.
We are enrolling patients in North America with ischemic heart disease who have been referred for angiography and are undergoing coronary function testing (CFT) for INOCA.
Once patients are enrolled, their providers will perform our study protocol, which follows guidelines from the American College of Cardiology and the European Society of Cardiology for evaluating and diagnosing chest pain.
First, we perform coronary angiography, where we take pictures of the blood vessels to look for blockages. From there, we test for vasospasm or endothelial dysfunction by injecting a medication called acetylcholine. Afterward, we assess the pressure and the flow in the vessels to diagnose if a patient has microvascular disease. Finally, we perform an intravascular imaging with ultrasound or optical coherence tomography of the entire blood vessel to look for plaque.
When we use a systematic approach we can diagnose the problem that is causing cardiac symptoms in our patients, while also characterizing the burden of plaque in their blood vessels. This protocol can help our patients understand what is happening within their bodies so they get an accurate diagnosis and treatment. If we can help patients get an accurate diagnosis, we can help improve their outcomes.
3. What outcomes are you studying?
We are following patients for five years to examine hard outcomes, like death, heart attacks, and stent procedures, so we can better understand why certain outcomes happen. For example, if a patient has a heart attack, is it because they already have a lot of plaque or atherosclerosis, or is it because something else is wrong with their blood vessels? We need a comprehensive assessment of the blood vessels to know the answer. This is the first study to do that at multiple centers in the United States.
We’re also the first multi-center INOCA registry that uses patient-reported outcome measures in a standardized way. We know patients with INOCA have higher rates of anxiety, depression, and recurrent symptoms than compared to patients with obstructive coronary heart disease. However, we’re still learning what factors contribute to this. We collect data upfront and at every interval using standardized questionnaires. This has not been done systematically in this population.
3. You have already enrolled more than 100 patients in the Registry. What initial results have you found?
We have found that if physicians use this standardized protocol on patients with these symptoms, 91% of people will have a change in diagnosis, and 76% will then have a change to their medications.
Anecdotally, people say they feel so much better. They feel happy to have a diagnosis, and that alone is therapeutic. But often, the right diagnosis leads to the right treatment. For example, coming off three of the wrong medications and going on just one effective drug is a big win for many patients.
In DISCOVER INOCA, there's no intervention. We're not telling people how to treat, but we care what people do with their medication. We'll be able to go back and see what regimens work for patients and which regimens don’t.
5. What do you hope this Registry achieves?
First of all, we want to ensure patients get the right diagnosis so that they can get on the right medication and have a higher quality of life.
Second, we want more health care providers to use this protocol in their practice. This is not something that can only be performed at a large academic center like Yale. Any institution with a cardiac catheterization lab can use this protocol with its patients. Technology has become much more widely available making this more accessible to health care institutions and their patients.
I also hope this will create momentum in the field to come up with consensus definitions of each diagnosis so we can identify drugs, devices, or other therapeutics to treat a specific diagnosis instead of just symptoms of chest pain.