More than 50 years of clinical results have shown that coronary artery bypass surgery is the most durable treatment for ischemic heart disease (coronary artery disease) with the most complete lesion resolution. And secondary risk prevention after bypass surgery is crucial to ensure the patency of coronary vessels and graft vessels and prevent adverse cardiovascular events.
Two of the most central components of secondary risk prevention are currently considered.
Antiplatelet therapy and lipid-lowering therapy.
Other aspects include good control of hypertension and diabetes, stopping smoking, weight loss and cardiac rehabilitation.
Anti-platelet therapy is recommended.
Aspirin should be started before surgery and within 6 hours after bypass surgery at a dose of 81-325 mg per day and continued for life to reduce graft occlusion and adverse cardiac events (I;A).
Two antiplatelet therapies should be applied concurrently for 1 year after nonstop bypass surgery, usually a combination of aspirin 81-162 mg + clopidogrel 75 mg daily to reduce graft vessel occlusion (I;A).
For patients who cannot tolerate aspirin or are allergic to aspirin, a switch to clopidogrel 75 mg daily is recommended and is recommended to be continued for life (IIa;C).
In patients undergoing coronary artery bypass surgery for the development of acute coronary syndrome, postoperative combination antiplatelet therapy with aspirin + prasugrel or aspirin + tegretol is recommended, and these recommendations have yet to be confirmed in relevant prospective studies (IIa;B).
In post-bypass patients treated with an antiplatelet therapy alone, a medium dose (325 mg/day) is more effective than a small dose (81 mg/day) if the patient is aspirin resistant, a finding that needs to be further confirmed (IIa;A).
One study recommended routine combined aspirin and clopidogrel therapy for one year also after extracorporeal bypass surgery, although the relevant findings are controversial (IIb;A).
Recommendations for antithrombotic therapy
Warfarin therapy does not improve the patency of the graft vessel. Therefore, routine antithrombotic therapy is not recommended after bypass surgery, unless the patient has atrial fibrillation, venous thromboembolism, or a mechanical valve implantation (III;A).
Routine application of other antithrombotic agents, such as dabigatran, apixaban, and rivaroxaban, is also not recommended after bypass surgery (III;C).
Recommendations for lipid-modifying therapy
All bypass surgery patients should receive statins, with treatment starting before surgery and resuming as soon as possible after surgery, except for patients with contraindications (I;A).
High-intensity statin therapy (40-80 mg for alvastatin and 20-40 mg for resulvastatin) is recommended for all post-bypass surgery patients younger than 75 years of age (I;A).
For patients who cannot tolerate high-intensity statin therapy and are at high risk of drug-drug interactions, a moderate-intensity regimen is recommended (I;A).
Discontinuation of statin therapy is not recommended before or after bypass surgery unless an adverse reaction to treatment occurs (III;B).
Recommendations for beta-blocker therapy
Preoperative initiation of betablockers is recommended in all patients undergoing bypass surgery to prevent postoperative atrial fibrillation, except in patients with contraindications such as bradycardia or severe reactive airway disease (I;A).
In patients with a history of myocardial infarction, postoperative treatment with betablockers is recommended, except in patients with contraindications (I;A).
Betablocker therapy (bisoprolol, betaxolol, carvedilol) is recommended in patients with bypass surgery with cardiac insufficiency, except in patients with contraindications (I;B).
Betablockers can also be used to treat hypertension in post-bypass patients (without history of infarction and cardiac insufficiency), but are less effective and more acceptable than other antihypertensive therapies, (IIb;B).
Recommendations for hypertension control
In patients without contraindications, early application of betablockers after bypass surgery reduces the risk of postoperative atrial fibrillation and facilitates postoperative blood pressure control (I;A).
In patients with a recent history of infarction, cardiac insufficiency, diabetes mellitus and chronic kidney disease, ACE (angiotensin-converting enzyme) blocker therapy is recommended after bypass surgery, and the timing and dose of the drug are determined by focusing on the patient’s renal function (I;B).
Blood pressure in patients after bypass surgery is recommended to be controlled by medication to 140/85 mmHg or less, (IIa;B).
Patients whose blood pressure is not controlled within the target blood pressure by betablocker therapy alone and ACE blocker therapy may be treated with additional calcium channel blockers and diuretics (IIa;B).
In patients without a history of infarction and cardiac insufficiency, postoperative antihypertension should be considered in addition to betablockers for long-term chronic hypertension management (IIb;B).
In patients without a recent history of infarction, cardiac insufficiency, diabetes mellitus, and chronic kidney disease, routine treatment with ACE blockers is not recommended because it may lead to side effects that may outweigh the benefits, along with unpredictable blood pressure reactions (III;B).
Treatment recommendations for patients with a history of infarction and cardiac insufficiency
Betablockers (bisoprolol, betalactam, carvedilol) are recommended for all patients with post-bypass left ventricular EF <40%, especially those with symptoms of heart failure or a history of previous infarction, except in patients with contraindications (I;A).
For all patients with post-bypass left heart insufficiency (EF <40%) or a history of infarction, treatment with ACE blockers or ARB agents is recommended, except in patients with contraindications (I;B).
For patients with symptoms of heart failure after bypass surgery and left heart insufficiency (EF<35%) in cardiac function class II-IV, treatment with aldosterone blockers is recommended in addition to the application of betablockers and ACE blockers, if there are no relevant contraindications (IIa;B).
For patients with left heart insufficiency (EF<35%) immediate postoperative installation of an ICD to prevent sudden cardiac death is not recommended. Adequate pharmacological treatment for 3 months is recommended, and if persistent left heart insufficiency remains before considering installation of an ICD (III;A).
Recommendations for the treatment of diabetes mellitus
Large group studies have shown that patients with moderate intensity glycemic control (127to179 mg/Dl) after bypass surgery have the lowest mortality and complications.
Efforts to control glycosylated hemoglobin to 7% or less is a reasonable goal for glycemic control in most post-bypass patients and may reduce diabetic microvascular complications and cardiovascular disease (IIa;B).
Smoking cessation recommendation
Smoking cessation is critical to improve near- and long-term outcomes after surgery, and therefore patients need to be consistently counseled to quit during hospitalization and after discharge (I;A).
For bypass smoking cessation patients who are stable after discharge, nicotine replacement therapy, such as the application of drugs like butalbital and varenicline, can be used if needed (IIa;B) Smoking cessation patients during hospitalization may perhaps be treated with nicotine replacement therapy, such as the application of drugs like butalbital and varenicline, but the treatment plan needs to be carefully considered for each patient’s individual situation, (IIb;B)
Cardiac rehabilitation recommendations
Postoperative rehabilitative therapy is recommended earlier during hospitalization for all bypass patients (I;A).
Cardiac rehabilitation of patients after hospital discharge covers two aspects
Medical guidance: some rehabilitation programs based on exercise
Specific core components of cardiac rehabilitation include.
Patient status assessment, nutritional counseling, risk factor management, lipids, blood pressure, weight, diabetes, smoking, psychosocial interventions, physical activity counseling and exercise training
Metabolic syndrome treatment includes.
Improving lifestyle habits, increasing physical activity, improving dietary structure, weight loss, diet, low carbohydrate, high protein, more fruits and vegetables, nonfat dairy products, and bariatric surgery can reduce the occurrence of metabolic syndrome
Obesity and metabolic syndrome treatment
It is recommended that post-bypass patients should have their waist and hip circumference measured frequently even if their BMI is in the normal range, because observing the waist/hip ratio is a better indicator of adverse obesity (IIa;C).
If the weight of post-bypass patients is not well controlled by lifestyle modification alone, bariatric surgery should be considered when BMI is >35 kg/m2 (IIb;C).
Nutritional aspects
Daily calories should be 30kcal/kg/d with 15% to 20% protein, 30% fat, 50%-55% carbohydrate from fruits and vegetables and moderate supplementation of vitamins (A, C, E) and omega-3 fatty acids
Vaccination recommendations
If there are no contraindications, annual influenza vaccination (I;B) is recommended for all bypass patients.