It is assumed that patients with non-ST-elevation myocardial infarctions (NSTEMI) showing an infero- or posterolateral occluded culprit artery (OCA) during diagnostic angiography frequently elude standard 12-lead electrocardiogram diagnosis. In addition, coronary collaterals may have beneficial effects in patients with OCA.

We examined consecutive NSTEMI patients within 48 h of symptom onset. All patients underwent early invasive angiography plus optimal medical therapy. We compared baseline characteristics, procedural findings including analysis of TIMI-flow and collaterals using the Rentrop-classification, 30-day and 6-months major adverse cardiovascular events (MACE) in patients with and without totally OCA.

Inclusion Criteria:

• age between 18 and 90 years,
• onset of angina pectoris at rest <24 h or crescendo angina in recent weeks with symptoms under minimal exertion or at rest lasting <24 h,
• elevated troponin T ≥0.03 µg/L and
• written informed consent.

Exclusion Criteria:

• persistent angina,
• ST-segment elevation myocardial infarction (STEMI),
• hemodynamic instability including cardiogenic shock,
• oral anticoagulation therapy,
• contraindications for glycoprotein IIb/IIIa inhibitors,
• other disease with life expectancy <6 months,
• known coagulopathy,
• pregnancy,
• other suspected causes of troponin elevation as myocarditis, secondary to hypertensive crisis, or after cardiac decompensation,
• no ability to consent, and
• participation in another study.