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No-reflow Phenomenon — EECC MCQ

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ModerateCoronary Artery DiseaseNo-reflow PhenomenonEECC

A 50-year-old man presents with ST elevation in leads V1-V4. Primary PCI is performed and a DES is deployed in the mid-LAD. Post-PCI, there is slow flow in the LAD (TIMI 2 flow) despite no residual stenosis. The myocardium supplied by the LAD appears viable. What complication has occurred?

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Correct answer: C — No-reflow phenomenon — microvascular obstruction from distal embolisation of atherothrombotic debris, microvascular spasm, and ischaemia-reperfusion injury; managed with intracoronary vasodilators (adenosine, verapamil, nitroprusside) and glycoprotein IIb/IIIa inhibitors

No-reflow is a significant complication of primary PCI occurring in 5-30% of STEMI cases. It represents microvascular obstruction (MVO) despite patent epicardial artery, caused by: (1) distal embolisation of plaque/thrombus debris during PCI; (2) microvascular spasm (endothelin release); (3) ischaemia-reperfusion injury (oxidative stress, oedema, capillary plugging by neutrophils/platelets); (4) pre-existing microvascular dysfunction. Treatment: (1) intracoronary adenosine (200-600 microg boluses — microvascular vasodilator); (2) intracoronary verapamil (100-200 microg); (3) intracoronary nitroprusside (100-200 microg); (4) intracoronary epinephrine (50-200 microg in refractory cases); (5) downstream GPIIb/IIIa inhibitor. Prevention: direct stenting (avoiding pre-dilation), aspiration thrombectomy in selected cases, and adequate antiplatelet/anticoagulant loading. No-reflow predicts larger infarct size, worse LV recovery, and higher mortality.

Reference: ESC (2023): ACS Guidelines