What is the initial treatment for Coronary Artery Disease (CAD)?

Initial Treatment for Coronary Artery Disease

All patients with CAD must immediately start four foundational therapies: aspirin 75-100 mg daily, high-intensity statin therapy targeting LDL-C <55 mg/dL, beta-blockers (especially if prior MI), and enrollment in supervised cardiac rehabilitation—these are non-negotiable starting points. 1, 2

Immediate Pharmacological Foundation (Start All Four)

Antiplatelet Therapy

• Aspirin 75-100 mg daily is the cornerstone antiplatelet agent for all patients with established CAD 1, 3
• Clopidogrel 75 mg daily is the alternative if aspirin is contraindicated 1
• Add a proton pump inhibitor (omeprazole 20 mg or pantoprazole 40 mg daily) if multiple GI bleeding risk factors exist 2

Lipid Management

• Start high-intensity statin therapy immediately with the dual goal of reducing LDL-C by ≥50% from baseline AND achieving LDL-C <55 mg/dL (<1.4 mmol/L) 1, 2, 3
• If goals are not met after 4-6 weeks on maximally tolerated statin, add ezetimibe 1, 2
• Consider PCSK9 inhibitors, inclisiran, or bempedoic acid for refractory cases, though clinical outcomes data for newer agents remain limited 1

Anti-Ischemic Therapy

• Beta-blockers are first-line for symptom control and are mandatory for at least 6 months in patients with prior MI 1, 2, 3
• Important caveat: Long-term beta-blocker therapy beyond one year is NOT recommended in patients without recent MI (within past year), LVEF ≤50%, or another primary indication 1
• Either beta-blockers OR calcium channel blockers can be used as first-line antianginal therapy—this represents a shift from older guidelines that prioritized beta-blockers exclusively 1
• Prescribe short-acting nitrates for immediate relief of effort angina 1, 2

Blood Pressure Control

• Target systolic BP 120-130 mmHg in general population, 130-140 mmHg in patients >65 years 1, 2, 3
• Critical pitfall: Exercise extreme caution when lowering diastolic BP below 60 mmHg in diabetic patients or those >60 years, as this may compromise coronary perfusion 3
• ACE inhibitors (or ARBs if not tolerated) are specifically recommended in patients with heart failure (LVEF <40%), diabetes, chronic kidney disease, or hypertension 1, 2, 3

Mandatory Lifestyle Modifications (Not Optional)

Cardiac Rehabilitation

• Enrollment in supervised exercise-based cardiac rehabilitation is mandatory—this provides significant cardiovascular benefits including decreased morbidity and mortality 1, 2, 3
• Patients should engage in habitual physical activity to reduce sitting time and increase both aerobic and resistance exercise 1

Dietary and Behavioral Changes

• Adopt a heart-healthy diet pattern (Mediterranean, DASH, or AHA diet) to reduce mortality 1, 2, 3, 4
• Smoking cessation is non-negotiable 1, 2, 3
• Weight control and stress management are essential 1, 2
• Do NOT recommend fish oil, omega-3 supplements, or vitamins—these lack benefit in reducing cardiovascular events 1

Additional Preventive Measures

• Annual influenza vaccination, especially for elderly patients 2
• Cognitive behavioral interventions to achieve and maintain lifestyle changes 2, 3
• Psychological interventions for depression symptoms 2

Risk Stratification and Diagnostic Evaluation

Initial Testing Strategy

• Non-invasive functional imaging (stress echo, SPECT, PET, or stress CMR) or coronary CTA is recommended as the initial diagnostic test in symptomatic patients with >5% pre-test probability of obstructive CAD 1, 2
• CCTA is preferred to rule out obstructive CAD in patients with low-to-moderate (5-50%) pre-test likelihood 1
• Resting echocardiography to quantify left ventricular function in all patients 2

High-Risk Features Requiring Invasive Evaluation

Invasive coronary angiography (ICA) with FFR/iFR assessment is recommended for patients with: 1, 2, 3

• Severe symptoms refractory to medical therapy
• Angina at low exercise threshold
• High-risk features on non-invasive testing:
  • Stress imaging showing ≥10% LV ischemia (SPECT/PET) or ≥3 segments with stress-induced dysfunction (echo) or ≥2 segments with perfusion defects (CMR)
  • CCTA showing left main ≥50% stenosis, three-vessel disease ≥70%, or proximal LAD disease ≥70%
  • Duke Treadmill Score <-10

Special Populations and Additional Considerations

Diabetes Management

• Sodium-glucose cotransporter-2 (SGLT2) inhibitors and GLP-1 receptor agonists are now recommended for select CAD patients, including those without diabetes 1
• Aggressive risk factor modification with careful blood glucose monitoring 2, 3

Antianginal Therapy Escalation

If symptoms persist despite first-line therapy, add second-line agents: 1

• Long-acting nitrates
• Ranolazine
• Nicorandil
• Ivabradine
• Trimetazidine

Revascularization Timing

• Myocardial revascularization is indicated when angina persists despite optimal antianginal drug therapy 1, 2, 3
• High-risk patients with LV systolic dysfunction, diabetes, and severe three-vessel or left main disease should be considered for CABG over PCI 2

Long-Term Monitoring

• Periodic cardiovascular healthcare visits to reassess risk status, lifestyle modifications, medication adherence, and development of comorbidities 1, 2, 3
• Routine periodic anatomic or ischemic testing without clinical change is NOT recommended—only repeat testing if symptoms worsen or new high-risk features develop 1, 2, 3
• Continue all medical therapy indefinitely regardless of revascularization decisions 2, 3
• Multidisciplinary team involvement (cardiologists, primary care, nurses, dieticians, physiotherapists, psychologists, pharmacists) improves outcomes 2, 3