Medical management of stable angina and ACS Flashcards
Define stable angina and describe the goals of treatment
- Stable angina characterized by chest discomfort upon exertion, relieved by rest or nitroglycerin
- Treatment objectives:
- Prevent/minimize ischemia and improve survival
- Reduce plaque progression and stabilize plaque (target LDL to at least half of what it was, decrease blood pressure)
- Prevent thrombosis in case of plaque rupture
- Minimize or eliminate symptoms
- Prevent/minimize ischemia and improve survival
- Medical therapy
- Nonpharmacologic and lifestyle measures
- Revascularisation with either percutanenous coronary intervention (PCI) or coronary artery bypass graft surgery (CABG)
Overall goal is to prevent unstable angina
NOTE:
Revascularisation has no real benefit.
If the quality of life is not affected, best to leave people with stable angina.
Describe general advice given to patients with stable angina
General Advice
- Informing patients and close associates of:
- Nature of angina
- Implications of diagnosis and potential treatments
- Advice for managing acute attacks:
- Rest and use of sublingual nitrate
- Informing patients about nitrate side effects and appropriate usage
- seeking medical help if symptoms persist for > 10 - 20 minutes
Describe non-pharmacological treatment for stable angina
- Smoking cessation
- Dietary advice
- Weight reduction if needed
- Moderation of alcohol consumption
- Encouraging exercise within patient’s limits
- Consumption of omega-3 fatty acids (fish oils) at least once weekly
- Appropriately managing coexisting conditions: diabetes, hypertension, anaemia, thyroid dysfunction
- Recommending annual flu vaccination
Describe pharmacological management for stable angina for improved prognosis
- Low-dose aspirin as anti-platelet treatment
- Clopidogrel for aspirin-intolerant patients
- Lipid-lowering therapy
- Statins for all patients
- Fibrates in patients with low HDL and high triglycerides, especially those with diabetes or metabolic syndrome
- Fibrates or nicotinic acid in addition to statins for high-risk patients with low HDL and high triglycerides
- Target LDL level: < 1.8 mmol/L ^[get it to at least half of what it was, in other words, trying to reduce based on person’s baseline; get it to <1.4 if instability]. Treat with statins or BCSK9, ezetimibe (a mon-statin lipid lowering drug)
- Beta blockers (e.g., metoprolol, atenolol)
- Especially post-MI or heart failure
- Reducing heart rate and contractility
- ACE inhibitors
- Especially for patients with coincident indications: Hypertension, heart failure, diabetes, chronic kidney disease
- ARBs
- Indicated for those intolerant of ACE inhibitors
- Heart failure or previous MI
Describe pharmacotherapy agents for symptoms and ischaemia reduction in stable angina
- Nitrates
- Systemic vasodilation to decrease myocardial oxygen demand
- Short-acting sublingual or long-acting oral/transdermal ^[patch for 8 hours]
- Nitrate-free period required
- Calcium channel blockers
- Systemic and coronary vasodilation
- Effective for vasospastic angina
- beta blocker is not tolerated or contraindicated
- addition to beta blocker, if monotherapy ineffective
- verapamil and diltiazem reduce myocardial contractility ^[side effects include bradycardia?]
- dihydropyridine CCBs e.g. amlodipine or felodipine are more vasoselective
- Systemic and coronary vasodilation
- Nicorandil ^[no revasc ability if very old?]
- K+ channel opener with nitrate-like effects
- Ivabradine ^[no revasc ability if very old?]
- Sinus node I channel inhibitor to slow heart rate
- Perhexilline
- Inhibits fatty acid oxidation, increases glucose oxidation
- Caution: hepatotoxicity and peripheral neuropathy (checking plasma levels)
Describe considerations for revascularisation in stable angina
Indicated with triple vessel disease, with requires revascularisation. Otherwise revascularisation has little benefit in stable angina.
- Revascularization when activity-limiting symptoms persist despite maximal medical therapy
- Considerations for revascularization:
- Active patients desiring improved quality of life through PCI
- Anatomy suitable for revascularization with proven survival benefit e.g. significant left main artery disease, or multivessel disease with reduced LVEF and large area of ischaemic myocardium
- Revascularization methods:
- Percutaneous coronary intervention (PCI) for 1 or 2 vessel disease, not a surgical candidate
- Coronary artery bypass grafting (CABG) for unprotected left main disease, 3 vessel disease + reduced LVEF
Describe diagnosis of acute coronary syndrome
Clinical Assessment
- Clinical history
- Electrocardiogram (ECG) findings
- (Serial) cardiac enzymes
Notes:
- STEMI: no preconditioning = myocardial electrical instability and arrhythmias
- Non-STEMI: can be due to cellular conditions OR collateral blood flow
- IF ST elevation AND no myocardial necrosis, troponin is likely above 100. NOT an MI
- IF ST elevation AND ACS, patient should be sent straight to cath lab
- NONST and ACS, patient should be addressed in 24 hours
Describe management of acute coronary syndromes
- Initial Medical Therapy: similar regimen to STEMI (ST-Elevation Myocardial Infarction) with some differences: there is no evidence of benefit (and possible harm) from fibrinolysis
- Sublingual nitroglycerin
- Intravenous nitroglycerin if pain persists after three tablets, or if there’s hypertension (HT) or congestive heart failure (CCF) ^[if sudden chest pain, administer nitrate, wait for 5 minutes and relax, and repeat three times: if no improvement, call 000]
- Caution in cases of right ventricular infarction, severe aortic stenosis (AS), recent use of PDE inhibitors
- Morphine for pain relief
- Beta blockers if no contraindication
- Beta blockers for ongoing chest pain, hypertension (HT), tachycardia not caused by CCF
Describe antiplatelet therapy in ACS
- Aspirin for all patients unless contraindicated
- 300mg loading, 100-150mg daily
- Thienopyridines (platelet P2Y12 receptor blockers)
- Clopidogrel (most common)
- 300-600mg loading, 75mg daily
- Continue for 12 months unless excessive bleeding risk
- Cease 5 days before coronary artery bypass graft surgery (CABG)
- Prasugrel
- Better efficacy, higher bleeding risk
- Ticagrelor
- Better efficacy, higher bleeding risk
- Clopidogrel (most common)
- Glycoprotein IIb/IIIa inhibitors (e.g., Abciximab, Eptifibatide, Bivalirudin)
- Used for recurrent chest pain, dynamic ECG changes
- Administered in cases of delay in cath lab or conservative approach (or after cath lab)
- Continued for 12 to 18 hours after percutaneous coronary intervention (PCI) depending on the agent
Discuss indications for early angiography and revascularisation
- Haemodynamic instability or cardiogenic shock
- Severe left ventricular dysfunction or heart failure
- Recurrent or persistent rest angina despite intensive medical therapy
- New or worsening mitral regurgitation or new ventricular septal defect
- Sustained ventricular arrhythmias
- Elevated cardiac biomarkers
- ST segment depression
- Recurrent angina
- Prior PCI within the prior six months or CABG
- Presence of diabetes mellitus
Discuss TIMI risk score for early angiography and revascularisation
This is used to assess whether it is safe to discharge patients, each represent a point. Do not discharge with a score of 2 or more, unless an extensive review and assessment. If there is a 0 score, there is a 1/300 risk of revisiting hospital.
- Age ≥65 years
- Presence of at least three risk factors for Coronary Heart Disease (CHD): hypertension, diabetes, dyslipidaemia, smoking, or positive family history of early MI
- Prior coronary stenosis of ≥50 percent
- Presence of ST segment deviation on admission ECG
- At least two anginal episodes in prior 24 hours
- Elevated serum cardiac biomarkers
- Use of aspirin in prior 7 days (possibly indicating more severe coronary disease)
Describe early management of ACS
- Relief of ischemic pain
- Assessment of hemodynamic state and correction of abnormalities
- Initiation of reperfusion therapy with primary PCI or fibrinolysis
- Antithrombotic therapy to prevent re-thrombosis or acute stent thrombosis
- Beta blocker therapy to prevent recurrent ischemia and life-threatening ventricular arrhythmias
Note: someone who is revascularised should not need 3rd or 4th line e.g. nitrates
Describe PCI
- Multiple randomized trials show enhanced survival compared to fibrinolysis
- Lower rate of intracranial hemorrhage and recurrent MI
- Door to balloon time should be < 90 minutes
- Consider within 12 to 24 hours after symptom onset in certain conditions
Describe fibrinolysis indication
- Applicable for patients with STEMI within 12 hours of symptom onset with:
- No contraindications for fibrinolysis
- Patient at a facility without primary PCI capability within 90 minutes of first medical contact
- Time from patient contact to lysis should be < 30 minutes
- Consider fibrinolysis up to 24 hours after symptom onset if ongoing chest pain
- Antiplatelet and heparin/LMWH co-therapy
- Emergency CABG in specific cases:
- failed thrombolysis or PCI
- cardiogenic shock
- life threatening arrhythmias with left main or 3 vessel disease
Describe discharge management
- Aspirin (100-150 mg/day) should be continued indefinitely unless it is not tolerated or an indication for anticoagulation becomes apparent: Strong IA
- Clopidogrel should be prescribed if aspirin is contraindicated or not tolerated: Strong IA
- Dual-antiplatelet therapy with aspirin and a P2Y 12 inhibitor (Clopidogrel or ticagrelor) should be prescribed for up to 12 months in patients with ACS, regardless of whether coronary revascularisation was performed. The use of prasugrel for up to 12 months should be confined to patients receiving PCI: Strong IA
- Consider continuation of dual-antiplatelet therapy beyond 12 months if ischaemic risks outweigh the bleeding risk of P2Y 12 inhibitor therapy; conversely consider discontinuation if bleeding risk outweighs ischaemic risks: Weak IIC
- Initiate and continue indefinitely, the highest tolerated dose of HMG-CoA reductase inhibitors/statins for a patient following hospitalisation with ACS unless contraindicated or there is a history of intolerance: Strong IA
- Initiate treatment with vasodilatory beta-blockers in patients with reduced LV systolic function i.e. LVEF< 40%, unless contraindicated: Strong IIA
- Initiate and continue ACE inhibitors or ARBs in patients with evidence of heart failure, LV systolic dysfunction, diabetes, anterior MI, or co-existent hypertension: Strong IA
- Attendance at cardiac rehabilitation or undertaking a structured secondary prevention service is recommended for all patients hospitalised with ACS: Strong IA
