The drug treatment of coronary heart disease is divided into two main parts
1.Prognosis improvement drugs
Anti-platelet aggregation drugs, β-blockers, lipid-regulating drugs ACEI.
2.Reducing symptoms and improving blood supply drugs
β-blockers, nitrate drugs, calcium antagonists.
Drugs to improve prognosis
1.Anti-platelet aggregation drugs
All patients should take aspirin as long as there is no contraindication to the drug (active gastrointestinal bleeding, aspirin allergy, history of intolerance to aspirin). Patients who cannot tolerate aspirin can be treated with clopidogrel as an alternative.
2.β-blockers
Beta-blockers can reduce the death rate and myocardial ischemia in post-MI patients, and should be taken by patients with stable angina after MI without contraindications. Beta-blockers are used in patients with heart failure.
The dose of β-blockers should be individualized, starting with a small dose and gradually increasing the dose to a heart rate of >50 beats per minute.
3.Lipid-regulating drugs
Statin lipid-modifying therapy is a milestone in the treatment of coronary heart disease in recent years, which can significantly reduce cardiovascular events and death. The guidelines recommend that all patients with coronary artery disease should take them to reduce LDL-C levels to below 2.60mmol/L (100mg/dl); for very high-risk patients (such as patients with combined diabetes or acute coronary syndrome), intensive statin lipid regulating therapy should be given to reduce LDL-C to below 2.07mmol/L (80mg/dl). Patients with diabetes mellitus or metabolic syndrome combined with low LDLC and hypertriglyceridemia receive fibrates or nicotinic acid analogs.
To achieve better lipid-lowering goals, ezetimibe 10 mg/d, a cholesterol absorption inhibitor, can be added to the statin application. patients with significantly elevated triglycerides can be treated with fibrates or niacin.
When using statins, biochemical indicators such as transaminases and creatine kinase should be closely monitored. Timely detection of drug may cause liver or myopathy, especially the use of intensive treatment room, more attention should be paid to monitoring the safety of drugs.
4.ACEI class drugs
ACEI class of drugs can reduce left ventricular remodeling to improve cardiac function, reduce the rate of death anterior wall infarction or a history of heart attack, heart failure and tachycardia and other high-risk patients benefit more.
The guidelines recommend ACEIs for all patients with combined diabetes, heart failure, left ventricular insufficiency, hypertension, and post-myocardial infarction left ventricular insufficiency. all patients with definite coronary artery disease use ACEIs.
Symptom-reducing and blood supply-improving drugs
Symptom-reducing and ischemia-improving drugs should be used in combination with drugs to prevent myocardial infarction and death. beta-blockers have both effects.
There are three types of drugs to reduce symptoms and improve ischemia.
1.β-blockers
Beta-blockers inhibit cardiac beta-adrenergic receptors, thereby slowing the heart rate, weakening myocardial contractility and lowering blood pressure to reduce myocardial oxygen consumption, which can reduce angina attacks and increase activity tolerance.
The use of beta-blockers and gradual increase to the maximum tolerated dose, the choice of dosage form and the frequency of administration should be able to anti-myocardial ischemia for 24 hours.
When beta-blockers are not tolerated or when beta-blockers are unsatisfactory as initial therapeutic agents, calcium antagonists, long-acting nitrates, or nicorandil may be used as symptom-reducing therapeutic agents.
When the effect of beta-blockers as the initial treatment drug is unsatisfactory, the combination of long-acting dihydropyridine calcium antagonists or long-acting nitrates
Contraindications: β-blockers are contraindicated in patients with severe bradycardia and high atrioventricular block, sinus node dysfunction, significant bronchospasm, and bronchial asthma. Peripheral vascular disease and depression of the major species are relative contraindications, and highly selective beta-blockers may be used with caution in chronic pulmonary heart disease. Ischemia caused by coronary spasm without fixed stenosis, such as variant angina, beta-blockers should not be used, and calcium antagonists are recommended to be preferred.
2.Nitrates
Nitrates are endothelium-dependent vasodilators, which can reduce myocardial oxygen demand and improve myocardial perfusion, and improve angina symptoms. Nitrates will reflexively increase sympathetic nerve tone to increase the heart rate, so often combined with negative rhythm drugs, such as beta-blockers and non-dihydropyridine calcium antagonists for the treatment of chronic angina pectoris. The anti-anginal effect of the combination is better than that of the drugs alone.
Sublingual or aerosol nitroglycerin is used for symptomatic relief of angina attacks and may also be used minutes before activity to reduce angina attacks. (Level of evidence for Class I indications B) Long-acting nitrates are not appropriate for the treatment of acute attacks of angina pectoris, but rather for chronic long-term treatment. Care should be taken to give adequate drug-free intervals with daily dosing to reduce the development of drug resistance. For example, patients with exertional angina pectoris should take the drug during the day and stop it at night, and skin dressing tablets should be applied during the day and removed at night.
Adverse effects: headache, flushing, reflex increase in heart rate, hypotension (more pronounced when taking short-acting nitrates). Angina pectoris due to severe aortic stenosis or hypertrophic obstructive cardiomyopathy should not be treated with nitrates. Because nitrate drugs can reduce the heart preload and reduce the left ventricular volume, which can further aggravate the degree of obstruction of the left ventricular outflow tract, and patients with severe aortic stenosis can further reduce the heart beat output due to the reduction of preload, which may cause the risk of syncope.
3.Calcium antagonists
Calcium antagonists relieve angina by improving coronary blood flow and reducing myocardial oxygen consumption. For variant angina or angina with predominant coronary spasm, calcium antagonists are the first-line drugs. Diltiazem and verapamil slow down atrioventricular conduction and are often used in patients with angina pectoris with atrial fibrillation or atrial flutter. They should not be used in patients with severe pre-existing bradycardia, high atrioventricular block, or sick sinus node syndrome.
When a long-acting calcium antagonist is necessary in patients with stable angina combined with chronic heart failure, amlodipine or felodipine is recommended.
Adverse effects: Peripheral edema, constipation, palpitations, and facial flushing are adverse effects of all calcium antagonists. Hypotension also occurs from time to time, and headache, dizziness, and fatigue may occur.
Long-acting calcium antagonists may be used as initial therapy in patients with coronary artery disease in combination with hypertension
When monotherapy with long-acting calcium antagonists or combined with β-blockers is unsatisfactory, replace or add long-acting calcium antagonists with long-acting nitrates or nicorandil, and use nitrates to avoid the development of drug resistance.
Calcium antagonists in combination with β-blockers: β-blockers can reduce the reflex tachycardia caused by dihydropyridine calcium antagonists, and the non-dihydropyridine calcium antagonists diltiazem and verapamil can be used as alternatives for patients with contraindications to β-blockers. Patients with bradycardia or left ventricular dysfunction should avoid using them.
4.Other drug therapy
(1) Metabolic drugs: Trimetazidine can improve myocardial ischemia and left heart function and relieve angina pectoris by mediating myocardial energy substrates, inhibiting fatty acid oxidation, and optimizing myocardial energy metabolism, and can be used in combination with β-blockers at the usual dose of 60 mg/d. It is divided into three oral doses.
(2) Nicorandil is a potassium channel opener with similar pharmacological properties as nitrates, and may be effective in stable angina. The usual dose is 6mg/d, divided into three oral doses.