[Acute coronary syndromes: an update. I. Pathogenesis and drug therapy]
1II. Interne Abteilung mit Kardiologie und Internistischer Intensivmedizin, Allgemeines Offentliches Krankenhaus der Barmherzigen Schwestern vom Heiligen Kreuz, Wels, Osterreich. johann.auer@khwels.at
Insights
Aspirin significantly reduces cardiac death and myocardial infarction in unstable angina. Other treatments like clopidogrel, glycoprotein IIb/IIIa inhibitors, and anticoagulants offer further risk reduction for acute coronary syndromes.
Area of Science:
- Cardiology
- Internal Medicine
Background:
- Unstable angina leads to over a million hospital admissions yearly.
- 6-8% of patients experience myocardial infarction or death within a year.
- Acute coronary syndromes encompass unstable angina and myocardial infarctions.
Purpose of the Study:
- To review the pathogenesis and treatment of acute coronary syndromes.
- To highlight the efficacy of antiplatelet and anticoagulant therapies.
Main Methods:
- Review of clinical trials and practice guidelines.
- Analysis of plaque disruption and thrombosis in acute coronary syndromes.
- Evaluation of pharmacological interventions including aspirin, clopidogrel, heparin, and glycoprotein IIb/IIIa inhibitors.
Main Results:
- Aspirin reduces cardiac death and myocardial infarction by 50-70% in unstable angina.
- Enoxaparin showed a lower composite endpoint incidence compared to unfractionated heparin.
- Glycoprotein IIb/IIIa inhibition benefits high-risk patients with refractory unstable angina.
Conclusions:
- Plaque disruption and thrombosis are central to acute coronary syndromes.
- Aspirin, anticoagulants, and other agents are crucial for managing unstable angina and acute coronary syndromes.
- Combination therapy, guided by clinical guidelines, improves patient outcomes.
Background:
Unstable angina accounts for more than one million hospital admissions annually. 6-8% of patients with this condition have non-fatal myocardial infarction or die within the first year after diagnosis. Recently, the term "acute coronary syndromes" has been used to describe the spectrum of conditions that includes unstable angina, non-Q-wave myocardial infarction (which generally presents without ST-segment elevation), and Q-wave myocardial infarction (which generally presents with ST-segment elevation).
Pathogenesis:
Disruption of a formed plaque is a complex pathologic process that is central to the initiation of the acute coronary syndromes. Local thrombosis occurring after plaque disruption results from complex interactions among the lipid core, smooth-muscle cells, macrophages, and collagen.
Treatment:
Multiple huge clinical trials confirmed that aspirin reduces the risk of death from cardiac causes and fatal and non-fatal myocardial infarction by about 50-70% in patients presenting with unstable angina. Ticlopidine may be substituted for aspirin in patients with hypersensitivity to aspirin or gastrointestinal intolerance. Clopidogrel acts similarly to ticlopidin but has fewer side effects than ticlopidine and has not been reported to cause neutropenia. High-risk patients with refractory unstable angina and elevated troponin levels may have substantial benefit of glycoptotein (GP) IIb/IIIa inhibition. Current practice guidelines support the use of the combination of unfractionated heparin and aspirin for the treatment of unstable angina. Clinical studies have demonstrated that the incidence of the composite end point of death, myocardial infarction, or recurrent angina was lower with enoxaparin than with unfractionated heparin. Beta-blockers, nitrates, and calcium-channel blockers are useful for antiischemic therapy in patients with acute coronary syndromes.
More Related Videos
Related Concept Videos
01:27Coronary Artery Disease V: Interprofessional Care
01:30Acute Coronary Syndrome I: Introduction
01:19Acute Coronary Syndrome II: Pathophysiology and Clinical Manifestations
01:30Acute Coronary Syndrome III: Diagnostic Studies
01:28Acute Coronary Syndrome IV: Interprofessional Care
01:26Angina IV: Management