Читать книгу Practical Cardiovascular Medicine - Elias B. Hanna - Страница 95

1 Emergent reperfusion with PCI or fibrinolytics is indicated in patients who present within 12 (24) hours of symptom onset and who have persistent ST elevation in two or more contiguous leads or ST depression that is isolated or most prominent in V1–V3 (class I recommendation for PCI or fibrinolytics at ≤12 h, class IIa for PCI at 12–24 h).¹ This applies even if ischemic symptoms have resolved, as long as ST elevation is persistent and the onset of ischemic symptoms is ≤24 hours.PCI is the preferred strategy, and it should be performed with a door-to-balloon time (DTB) of ≤90 min in patients presenting to PCI- capable hospitals, and ≤120 min in patients transferred from non-PCI-capable to PCI-capable hospitals. If PCI cannot be performed with a DTB of ≤120 min, fibrinolytics should be given to patients presenting within 12 hours of symptom onset (initiated ≤ 10 min from diagnosis).^* Regardless of the setting, the DTB that mitigates PCI’s benefit over fibrinolysis is 120 min (ESC).

2 Patients presenting >24 hours after symptom onset generally do not have an indication for emergent PCI. Emergent PCI (not fibrinolysis) is selectively indicated in some of these patients, such as patients with persistent ischemic symptoms, cardiogenic shock, acute severe HF with massive pulmonary edema, or when the onset of STEMI is not clearly >24 hours.Otherwise, non-urgent coronary angiography and PCI are indicated in patients with recurrent chest pain at rest or mild exertion or severe ischemia on stress testing.

While a timely primary PCI is favored over fibrinolysis in all STEMI patients, it is more heavily favored in the following circumstances, where the efficacy of fibrinolysis is reduced:

 Cardiogenic shock or severe HF attributed to STEMI should undergo emergent PCI regardless of the delay to presentation (even if >24 hours). Fibrinolytics should not be a standalone therapy for cardiogenic shock but may be used en route to PCI in early presenters, when delays are expected.

 Late presenters, 3–12 hours.

 Age >75 years.

 History of CABG with suspicion of SVG thrombosis. Both PCI and fibrinolytics have reduced efficacy in this high-risk subset, but PCI remains more effective than fibrinolytics. PCI re-establishes TIMI 3 flow in 50–70% of SVG MIs, vs. 25–50% with fibrinolytics.

 ECG is not definite for STEMI (e.g., LBBB without ST concordance) or time of onset of symptoms is unclear (may be >12 hours).

Myocardial effect of reperfusion therapy:

 In the first 2–3 hours, reperfusion prevents myocardial necrosis.

 Between 3 (or 6) and 12 hours, reperfusion may not prevent further necrosis, but treats peri-infarct ischemia, prevents deleterious remodeling, improves scar turgor, and decreases mortality (absolute mortality reduction >2%).