[Evidence-based management of ST-segment elevation myocardial infarction (STEMI). Latest guidelines of the European Society of Cardiology (ESC) 2010].
Acute myocardial infarction and its consequences (death, chronic ischemic coronary artery disease, heart failure) are still the number 1 causes of death and of cardiovascular diseases in Germany. In this context, patients with STEMI are at the highest risk. The first-line management of STEMI patients often determines if the outcome is life or death. This overview presents the current optimal evidence-based management of STEMI patients as a practice-oriented extract according to the latest ESC guidelines, fully published some weeks ago (http://www.escardio.org).All efforts must be made to keep the respective time intervals between the onset of symptoms and the beginning of reperfusion therapy as short as possible, i.e. best within a dedicated STEMI network. Two of the time intervals are particularly essential: the time delay between the onset of symptoms and the first medical contact (FMC) and the time delay between FMC and the beginning of reperfusion. The time delay between the onset of symptoms and FMC depends on the patient as well as on the organization of the emergency medical service (EMS). Unfortunately, too many patients/bystanders still hesitate to immediately call the EMS. More intense measures must therefore be taken to educate the public. The optimal FMC by medical doctors or paramedics reacts quickly and ideally arrives with ECG equipment for immediate diagnosis of STEMI (persistent ST-segment elevation or presumably new left bundle branch block) before hospital admission. Unfortunately in many cases, the FMC is the emergency room of a hospital. Further decisions can be made without laboratory findings. In Germany, the average time delay between onset of symptoms and FMC is 100 min and therefore longer than in some other European countries.The next critical time interval is that between FMC and the beginning of reperfusion: this interval depends solely on the EMS organization and the distance to the next catheter laboratory with 24 h PCI (percutaneous coronary intervention) availability. The key question for further decisions is whether a primary PCI can be performed within 120 min after FMC. If so, the primary PCI should definitively be preferred. In patients <75 years presenting with a large anterior infarction within 2 h after onset of symptoms, this time interval should not exceed 90 min. For primary PCI an often used measure of quality is the "door-to-balloon" time, which should of course be as short as possible. Therefore, patients with STEMI should be admitted directly to the catheterization laboratory bypassing the emergency room or intensive care unit. In Germany, the average time interval between FMC and start of primary PCI is approximately 120 min just at the upper limit of the guideline recommendations. Some other European countries report a significantly shorter corresponding time delay.If primary PCI is not possible within 120 min (or 90 min) after FMC, thrombolysis must be initiated within 30 min after FMC, either in the EMS ambulance or in a nearby non-PCI hospital. A thrombolytic therapy, however, even if "successful", is not the final therapy: within 24 h (but not before 3 h) cardiac catheterization has to be performed with PCI, if applicable. Analyzing the overall revascularization rates in Germany, 81% receive primary PCI, 7% thrombolysis and 12% no reperfusion therapy. Regarding any reperfusion in STEMI, Germany holds the third place after the Czech Republic and Belgium.Patients presenting at 12-24 h after onset of symptoms or later may possibly benefit from a PCI, even if already asymptomatic, if signs of ischemia/viability in the infarct artery-related area are demonstrable. If this cannot be shown, PCI in these patients is not indicated.The first-line medication aims at dual antiplatelet therapy (DAPT) and anticoagulation. For DAPT, the combination of ASA with a thienopyridine is mandatory. If primary PCI is feasible, DAPT with prasugrel (loading dose of 60 mg, independent of age and weight) is preferred due to its faster onset of action and superior effectiveness over clopidogrel (loading dose of 600 mg). In patients with STEMI, prasugrel when compared to clopidogrel significantly reduced nonfatal myocardial infarction after 15 months from 9.0% to 6.8% and stent thrombosis significantly from 2.8% to 1.6% (ARC definite/probable). If, however, there are contraindications against prasugrel (s/p stroke or TIA) or if thrombolysis had to be performed, clopidogrel is the choice for DAPT.The i.v. administration of glycoprotein IIb/IIIa inhibitors (GPI) has been limited to only those patients with a high intracoronary thrombus burden. The upstream application of GPI is not recommended. Recommendations for the mechanical treatment of thrombus burden include manual thrombus aspiration (which was upgraded) and a mesh-based protection stent device (MGuard™). For anticoagulation, unfractionated heparin (UFH) is recommended as always but bivalirudin is an upcoming alternative, either in the catheterization laboratory on top after an EMS-delivered UFH bolus or as a possible first-line monotherapy. Bivalirudin may be preferred in STEMI patients with a high risk of bleeding. To prevent possible thrombotic events after PCI, bivalirudin should be continued for several hours after primary PCI.Regardless of whether PCI or thrombolysis was the first-line therapy and regardless of whether a stent (BMS or DES) was implanted, DAPT should be continued for 12 months with prasugrel 10 mg/day (or 5 mg/day, if ≥75 years old and/or <60 kg body weight) or clopidogrel (75 mg/day). There is no evidence that higher maintenance doses of clopidogrel may circumvent possible clopidogrel resistance. The usefulness of so far non-standardized in-vitro platelet aggregation measurements or the practice-oriented interpretation of genetic tests for CYP2C19 polymorphism is unknown. With the 12 months DAPT the patient is treated not the stent.
Kardiologische Praxis und Praxisklinik, Akademische Lehrpraxis der Ludwig-Maximilans-Universität München, Am Isarkanal 36, 81379, München. sigmund@silber.com
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D000359:Aftercare; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects; D002317:Cardiovascular Agents / Q000627:therapeutic use; D000077144:Clopidogrel; D003131:Combined Modality Therapy; D000075202:Contraindications; D004562:Electrocardiography; D004632:Emergency Medical Services; D004636:Emergency Service, Hospital; D005060:Europe; D019317:Evidence-Based Medicine; D006801:Humans; D008019:Life Style; D009203:Myocardial Infarction / Q000175:diagnosis / Q000401:mortality / Q000534:rehabilitation / Q000628:therapy*; D015425:Myocardial Reperfusion; D010879:Piperazines / Q000008:administration & dosage / Q000009:adverse effects; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D017410:Practice Guidelines as Topic; D000068799:Prasugrel Hydrochloride; D013876:Thiophenes / Q000008:administration & dosage / Q000009:adverse effects; D015912:Thrombolytic Therapy; D013988:Ticlopidine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives; D013997:Time Factors
D000925:Anticoagulants; D002317:Cardiovascular Agents; D010879:Piperazines; D010975:Platelet Aggregation Inhibitors; D013876:Thiophenes; D000077144:Clopidogrel; D000068799:Prasugrel Hydrochloride; D013988:Ticlopidine