Latent coronary heart disease, also known as asymptomatic coronary artery disease, is coronary artery disease (CAD) where there are no symptoms of angina pectoris, but objective evidence of myocardial ischemia is present. Evidence of myocardial ischemia on ECG may appear at rest or only under stress conditions. It is often detected through dynamic ECG monitoring or confirmed by various imaging examinations.
Clinical manifestations
Latent coronary heart disease can be classified into three types:
- Objective evidence of myocardial ischemia without symptoms of angina pectoris
- A history of myocardial infarction with current evidence of myocardial ischemia but no symptoms
- Episodes of myocardial ischemia that are sometimes symptomatic and sometimes asymptomatic
Asymptomatic myocardial ischemia is more frequently observed in diabetic patients. It is crucial to identify such patients early and provide prompt treatment to prevent myocardial infarction or death.
Diagnosis
Non-invasive testing provides important objective evidence for diagnosing myocardial ischemia. Different diagnostic approaches are chosen based on the patient's risk level:
- Resting, dynamic, or stress ECG testing
- Further evaluation with carotid intima-media thickness (IMT), ankle-brachial index (ABI), or coronary CTA to assess coronary stenosis and calcification scores
- Myocardial perfusion imaging, coronary angiography, or intravascular ultrasound (IVUS)
Currently, imaging examinations are not recommended for low- to moderate-risk patients, nor is routine screening advised for all asymptomatic individuals.
Differential diagnosis
Various organic heart diseases can cause ischemic ST-T changes, which should be differentiated accordingly.
Prevention and treatment
Patients diagnosed with latent coronary heart disease should receive pharmacological treatment to prevent myocardial infarction or death, as well as management of associated risk factors. Treatment recommendations are generally similar to those for chronic stable angina.
For asymptomatic patients without contraindications, the following medications should be used to prevent myocardial infarction and death:
- Aspirin and beta-blockers for patients with a history of myocardial infarction
- Statins for lipid-lowering therapy in patients with confirmed CAD or type 2 diabetes
- RAAS inhibitors for patients with diabetes and/or impaired cardiac systolic function
Recommendations for revascularization to improve prognosis in chronic stable angina patients also apply to latent coronary heart disease, though direct evidence is currently lacking.