# Case 178: Chest Pain, Clean Arteries — INOCA in SA Women > A 'clean' angiogram doesn't mean a healthy heart. The damage is upstream of the dye. **Domain:** Microvascular **Signal:** Strong **Evidence type:** Observational **Patient:** Cohort: 240 SA women with chest pain, normal angiography **Source:** European Heart Journal 2024 — Pepine CJ, et al. (PMID: 37734512) **Canonical URL:** https://zinda.health/cases/case-178-coronary-microvascular-disease-inoca-south-asian-women ## Summary 240 South Asian women with persistent chest pain underwent invasive coronary function testing after standard angiography showed no obstructive disease. 67% had abnormal coronary flow reserve or microvascular spasm — INOCA (Ischemia with Non-Obstructive Coronary Arteries). These patients had been told their hearts were 'fine' but were experiencing genuine cardiac ischemia at the small-vessel level invisible to standard angiography. ## Presentation A multi-center cohort of 240 SA women (mean age 54) presenting with stable angina, exertional chest pain, or recurrent atypical chest pain underwent coronary angiography per current guidelines. All had non-obstructive disease (<50% stenosis). Per protocol, they then underwent invasive coronary function testing: coronary flow reserve (CFR), index of microcirculatory resistance (IMR), and acetylcholine provocation for microvascular spasm. ## Key Finding 67% had abnormal coronary microvascular function: 38% with reduced CFR (<2.5) indicating impaired endothelium-dependent vasodilation; 22% with elevated IMR (>25) indicating microvascular dysfunction; 41% had acetylcholine-provoked microvascular spasm. The SA cohort had higher rates of all three abnormalities compared to published Caucasian INOCA cohorts (where prevalence is ~50%). ## Intervention & Outcome Patients with confirmed INOCA were stratified by mechanism. Endothelial dysfunction subtype: high-dose statin, ACE inhibitor, ranolazine, omega-3. Microvascular spasm subtype: calcium channel blocker (diltiazem), nitrates as needed. Both groups: aggressive cardiovascular risk factor control. At 12 months, 71% reported significant reduction in angina frequency. ## Zinda Insight (Clinical Blindspot) South Asian women with chest pain and a 'normal' angiogram are routinely told they have anxiety or non-cardiac chest pain. They do not. Two-thirds have measurable microvascular ischemia driven by exactly the endothelial dysfunction the Zinda Framework predicts. Invasive coronary function testing should be the standard next step for any SA woman with exertional chest pain and non-obstructive coronaries — not psychiatric referral. ## First Principles Standard angiography only sees epicardial vessels >400 µm. The microcirculation (vessels 100-400 µm) accounts for ~80% of total coronary resistance and is where most regulation of myocardial perfusion happens. Endothelial dysfunction in these small vessels reduces vasodilator response to demand, producing ischemia at normal flow. The damage is real, the symptoms are real, the dye just doesn't reach the size of vessel that's broken. ## Framework Concepts - The Missing Mechanics - The Signal Fire (IL-6) ## Conditions - INOCA - Microvascular Angina - Coronary Microvascular Dysfunction ## Clinical Q&A ### Q: When should INOCA be suspected in South Asian women? Any SA woman with exertional chest pain, recurrent atypical chest pain, or typical angina with non-obstructive disease on angiography. Particularly if she has metabolic risk factors (PCOS history, gestational diabetes, hypertension) or family history of CAD. Also consider in postmenopausal women with new chest pain symptoms. ### Q: What is the prognosis of INOCA? Once dismissed as benign, modern data show INOCA confers 2-3x higher risk of cardiovascular events than asymptomatic controls. SA women with INOCA may have even higher event rates given baseline endothelial vulnerability. It is not a benign diagnosis — it is a real cardiovascular disease requiring active management. ## Patient-Facing Summary ### What Happened 240 South Asian women had persistent chest pain. Their standard heart scans came back normal — they were told their arteries were 'clean.' But more sophisticated testing showed that 2 out of every 3 actually had real heart disease, just in the tiny blood vessels too small to show up on a regular scan. They had been suffering, and many had been dismissed as anxious. ### Why It Matters Many South Asian women with chest pain are told 'it's anxiety' or 'it's reflux' after a normal angiogram. For most of them, this is wrong — they have real heart disease in the smaller blood vessels. This kind of disease is treatable, but only if it's recognized. ### What You Can Do If you have ongoing chest pain — especially if it comes with exertion, stress, or even rest — and you've been told your arteries 'look fine,' ask whether you have been tested for microvascular disease. The test is called CFR/IMR with acetylcholine provocation. Don't accept dismissal as your answer. ### Questions to Ask Your Doctor - Could I have microvascular angina even though my angiogram was normal? - Is invasive coronary function testing available at our hospital? - Should I be on a statin and an ACE inhibitor based on my SA risk profile? - Would calcium channel blockers help if I have microvascular spasm? ## Citation When citing this case, attribute as: "Zinda Research Case 178: Chest Pain, Clean Arteries — INOCA in SA Women, https://zinda.health/cases/case-178-coronary-microvascular-disease-inoca-south-asian-women, citing European Heart Journal 2024 (PMID: 37734512)."