Table 4. Key messages.

1	Angina pectoris is the most common symptom of ischaemic heart disease affecting many millions of people globally.
2	A large proportion of patients undergoing coronary angiography because of angina and evidence of myocardial ischaemia do not have obstructive coronary arteries but have demonstrable ischaemia. This entity is defined as INOCA (Ischaemia with Non-Obstructive Coronary Arteries).
3	INOCA is found more frequently among women (50-70%) than among men (30–50%) undergoing coronary angiography for angina.
4	Coronary microvascular dysfunction (CMD), alone or in combination with CAD, is a mechanism of myocardial ischaemia and symptoms in INOCA.
5	INOCA is not a benign condition and associated with comparable incidence of adverse events as well as impaired quality of life as obstructive CAD.
6	INOCA is often not diagnosed and, therefore, no tailored therapy is prescribed for these patients whose symptoms are often dismissed or downplayed.
7	Multiple non-invasive techniques including TTDE, MCE, PET, MRI, and SPECT are available to detect ischaemia in INOCA.
8	Invasive strategies, using coronary angiography and interventional diagnostic procedure consisting of a diagnostic guidewire, pressure and flow measurements, and pharmacological coronary reactivity testing in the catheterization laboratory, should be implemented to differentiate be tween vasospastic angina, microvascular angina and non-cardiac pain.
9	A stratified approach to the management of INOCA to address the short and long-term prognosis in these patients is warranted. This includes tailored counselling on lifestyle factors, risk factor management as per CVD prevention guidelines and use of pharmacotherapy to alleviate ischaemia and symptoms.
10	A current large randomized, controlled strategy trial (WARRIOR NCT03417388) is testing if all INOCA patients should be treated with ACEI and statins.
11	For patients experiencing vasospastic angina, calcium channel blockers, followed by nitrate therapy should be administered and, if still symptomatic, the use of nicorandil should be considered.
12	For patients in whom a diagnosis of microvascular angina has been established based on abnormal coronary flow reserve and/or high microcirculatory resistance (suggesting microvascular remodelling), an initial therapy with beta-blockers should be considered, followed by use of calcium channel blockers. When symptoms continue, use of nicorandil, ranolazine and EECP can be considered.
13	For patients in whom the diagnosis of microvascular angina is based on the presence of microvascular spasm, an initial therapy with calcium channel blockers should be considered, followed by use of ranolazine and EECP can be considered.
14	The use of low-dose tricyclic antidepressants, such as imipramine and xanthine derivatives, may be helpful to reduce the intensity of symptoms.
15	Given the lack of in-depth knowledge, further research is urgently needed to increase our mechanistic understanding and to develop innovative tailored therapies in order to better manage this serious condition.
ACE: angiotensin-converting enzyme inhibitor; CAD: coronary artery disease; CFR: coronary flow reserve; CVD: cardiovascular disease; EECP: enhanced external counter pul.sation; MCE: myocardial contract echocardiography; MRI: magnetic resonance imaging; PET: positron emission tomography; SPECT: single-photon emission computed tomog.raphy; TTDE: trans thoracic Doppler echocardiography.