Angina with non-obstructive coronary arteries (ANOCA) is a common syndrome with unmet clinical needs. Diagnosis in patients can be challenging due to the uncertain association between invasive diagnostic tests and non-invasive ischaemia test results.
In this video, Prof Colin Berry (University of Glasgow, Glasgow, UK) discusses the most appropriate tests to diagnose ANOCA, how to identify the symptoms and summarises the most appropriate treatment strategies.
What is the definition of ANOCA and what is disease prevalence?
What are the symptoms of ANOCA?
Which tests would be best suited to diagnose ANOCA and is there data to support these approaches?
How is ANOCA treated once diagnosed?
Filmed in London at BCIS ACI 2020.
Interviewer: Mirjam Boros
Videographer: Natacha Wienand / Dominic Woodruff
Transcript Below :
Question 1 : What is the definition of ANOCA and what is disease prevalence?
[Berry] ANOCA is angina with no obstructive coronary arteries. It is what it says on the tin, so the clinician should be clear that the symptom is indeed angina. It's a cardiac symptom, consequent on myocardial ischemia in a patient who has unobstructed coronary arteries. And the implication is that this is the syndrome of ischemia with no obstructive coronary arteries. In other words, INOCA with microvascular angina and/or vasospastic angina implicated. In terms of prevalence, in unselected patient populations, such as referrals to a chest pain clinic, potentially two in five patients with angina, possibly higher, and certainly higher than those patients with obstructive coronary narrowings, who represent the small minority of patients attending a chest pain clinic.
Question 2 : What are the symptoms of ANOCA?
[Berry] The symptoms of ANOCA are a sense of insufficiency in the chest that may manifest as chest pain, throat tightness, radiating to the left arm. The symptoms may occur with effort, as is typical angina, or they may be less typical, occurring spontaneously, such as after, with emotional stress, sometimes at night, sometimes hours after exertion, and the patient starts to become habituated to these symptoms so they can become typical for the patient, even if they may be atypical for the clinician.
Question 3 : Which tests would be best suited to diagnose ANOCA and is there data to support these approaches?
[Berry] Tests should be personalised to the patient and the setting. So, if the clinician is undertaking a review of a patient in the outpatient setting, then non-invasive tests would be relevant. To confirm a diagnosis of ANOCA, coronary angiography would be relevant, potentially by CT. And then inducible ischaemia should be assessed with stress echocardiography or stress perfusion MRI or indeed PET. In the cath lab, where patients might be selected for invasive management, then a diagnostic guidewire to measure coronary flow reserve and coronary resistance, and if available with experience, provocative testing with acetylcholine.
Question 4 : How is ANOCA treated once diagnosed?
[Berry] Again, treatment should be personalised to the patient. Is this the first time, the first interaction with the patient? Are they naive to therapy? Or is this a patient who has had anginal symptoms for many years, has potentially passed between different clinicians with different treatments? So, at the point of care, one needs to be mindful about the treatments for the patient. For microvascular angina, a beta blocker may be helpful. Where there is microvascular spasm or epicardial spasm, a calcium channel blocker can be helpful. Nitrates can be helpful for microvascular angina. And then preventive therapies if there is atherosclerosis, an antiplatelet, a statin, and potentially an ACE Inhibitor balanced against the blood pressure level.