Related Experiment Videos
[Nitrates in unstable angina]
1Serviço de Cardiologia, Hospital de Santa Marta, Lisboa.
Insights
Unstable angina, a critical heart condition, requires aggressive treatment including nitrates and aspirin to prevent heart attack. Early revascularization via angioplasty or surgery may be necessary for severe cases.
Area of Science:
- Cardiology
- Internal Medicine
Context:
- Unstable angina is an acute coronary syndrome.
- It presents distinct clinical and laboratory features compared to stable angina and myocardial infarction.
- Pathologically, it involves plaque rupture, thrombus formation, and coronary artery occlusion.
Purpose:
- To outline the clinical presentation and pathological mechanisms of unstable angina.
- To discuss current therapeutic strategies, including medical management and revascularization procedures.
- To highlight the risks and benefits associated with different treatment modalities.
Summary:
- Patients with unstable angina face a high risk of myocardial infarction and death.
- Aggressive therapy in an Intensive Coronary Care Unit is crucial, involving beta-blockers, calcium antagonists, nitrates, and aspirin.
- Heparin and thrombolytic therapy remain subjects of debate, though heparin is common in acute phases.
- Coronary angiography guides further management with percutaneous transluminal coronary angioplasty (PTCA) or coronary bypass surgery for refractory cases.
Impact:
- Aspirin significantly reduces the risk of death and myocardial infarction.
- Early revascularization through PTCA or bypass surgery can be beneficial, particularly in selected patients.
- PTCA, despite a higher complication rate than elective procedures, reduces late infarction and death in cases with initial success.
- Surgical revascularization improves outcomes and survival in patients with reduced left ventricular function.
Abstract:
Unstable angina is an acute coronary syndrome between stable angina and myocardial infarction, with different clinical and laboratory features. Angiographically, these patients are more likely to have progression of coronary artery disease, vasospastic phenomena and intracoronary thrombus. Sudden plaque rupture, thrombus formation and the occlusion of an epicardial coronary vessel seem to be the underlying pathological mechanism. Patients with unstable angina are at an increased risk of major complications, especially fatal and nonfatal myocardial infarction, justifying an aggressive therapy in an Intensive Coronary Care Unit with beta-blockers, calcium antagonists and, in particular, nitrates, usually in association. The use of antiplatelet agents, namely aspirin, has been proved to be beneficial significantly reducing the risk of death and myocardial infarction. On the other hand, heparin and thrombolytic therapy are still a matter of some controversy, although the former is largely used in the acute phase. Coronary angiography should be done in all patients refractory to medical treatment to allow further management of the underlying coronary lesions by PTCA or coronary bypass surgery. However, some authors have advised a more aggressive attitude, performing the revascularization in an early phase. Randomized studies have shown that, with surgery, only patients with reduced left ventricular function may improve with the procedure, having a better two-year survival rate. Concerning PTCA, although the complication rate is somewhat higher than in the elective procedure, the probability of late infarction and death is significantly reduced in patients in which there was initial success.