Dr Fiona Foo General and interventional cardiologist, Sydney Cardiology Group, MQ Health Cardiology, Macquarie University Hospital and Sydney Adventist Hospital, Sydney, NSW; co-vice chair, Doctors for the Environment Australia NSW Committee.

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This information was correct at the time of publication: 20 June 2025

INTRODUCTION

ISCHAEMIC heart disease( IHD) is a

constellation of disorders with myocardial

ischaemia as the common pathophysiological mechanism. 1 IHD is used interchangeably with coronary heart disease( CHD) and coronary artery disease( CAD). 2 In these chronic coronary syndromes, a mismatch between the demand and supply of coronary artery blood flow may lead to transient or recurrent cardiac chest pain( angina is the most common symptom) related to myocardial ischaemia from inadequate cellular availability of adenosine 5’-triphosphate. 3

IHD was the second leading cause of death in Australian women in 2023( 6579 deaths)— 18 women / day; and the fourth leading cause of years of life lost in women in 2023. 4, 5

IHD mortality rates in young women are increasing, and it is no longer considered a problem affecting only postmenopausal women. 6 There are significant differences in the pathophysiology of CAD between women and men, including a higher prevalence of non-obstructive CAD in women. 7 Traditional cardiovascular

( CV) risk factors play an important role in the development of IHD in women; however, sex-specific risk factors( eg, adverse pregnancy outcomes) and other non-traditional risk factors( eg, autoimmune disease, psychosocial contributors) disproportionately affect women. 8

Significant sex disparities exist in the treatment, morbidity and mortality for women with IHD and acute coronary syndromes( ACS). 9-11 Factors contributing to these disparities include limited awareness of heart disease among women and inaccurate assessment of risk by healthcare

12, 13 professionals. There are notable sex differences in pathophysiology, with women more likely to have non-obstructive CAD. 7, 14 Women also have more angina at baseline compared with men. 15 There are sex disparities in management— women are less likely to receive coronary angiography and percutaneous intervention after myocardial infarction( MI) and be discharged with guideline-directed medical therapy

16, 17

( GDMT) compared with men. Traditionally, IHD was thought to result from flow-limiting

atherosclerotic obstructions of the coronary arteries; however, mounting evidence indicates that non-epicardial coronary artery causes of angina and ischaemia are more prevalent than flow-limiting stenoses. 18 Up to 70 % of patients undergoing coronary angiography for angina do not have obstructive CAD( defined as more than 50 % stenosis in epicardial coronary arteries), despite having demonstrable

19, 20 ischaemia. Patients with IHD with non-obstructive CAD may be diagnosed with angina with non-obstructive coronary arteries( ANOCA), ischaemia with non-obstructive coronary arteries( INOCA) or MI with non-obstructive coronary arteries( MINOCA). Research over the past two decades has significantly improved the understanding of IHD in women, including the mechanisms of INOCA and MINOCA. In INOCA, the mismatch between blood supply and myocardial oxygen demands may be caused by coronary microvascular dysfunction( CMD) and / or epicardial coronary artery spasm, usually in the setting of non-obstructive coronary atherosclerotic cardiovascular disease( ASCVD). 21 ANOCA,

INOCA and MINOCA are more common in women.

22, 23

The multiple mechanisms of myocardial ischaemia appear in figures 1,

24, 25

2 and 3. This How to Treat provides an overview of stable / chronic IHD and acute myocardial infarction( AMI) in women, which may be due to obstructive and non-obstructive CAD. It aims to increase awareness and understanding of ischaemia in women, including INOCA and MINOCA, and the differences in IHD between women and men.

Other causes of ischaemia, such as myocardial infiltration and aortic stenosis, are beyond the scope of this article.

STABLE IHD

Epidemiology and pathophysiology

ANGINA or ischaemia may result

from obstructive or non-obstructive CAD. Most patients with chronic angina do not have epicardial obstructions. 26 In the SCOT- HEART trial of patients with known or suspected stable CAD, most( four in five individuals) did not have