Ischaemic heart disease

Ischaemic heart disease (IHD) is an umbrella term for all conditions characterised by ischaemia of the myocardium. Because this is almost always due to coronary artery atherosclerosis, the term coronary artery disease (CAD) is virtually equivalent to IHD and they’re often used interchangeably.

We can distinguish acute and chronic ischaemic heart disease. Acute ischaemic heart disease is referred to as acute coronary syndrome (ACS). Chronic ischaemic heart disease is referred to as chronic coronary syndrome (CCS) or stable ischaemic heart disease.

Ischaemic heart disease includes the following syndromes:

• Acute coronary syndrome (ACS)
  • ST-elevation myocardial infarction (STEMI)
  • Non-ST elevation ACS (NSTE-ACS)
    • Non-ST elevation myocardial infarction (NSTEMI)
    • Unstable angina (UA/UAP)
• Chronic coronary syndrome (CCS)
  • Effort angina/stable angina
  • CCS with “anginal equivalent”
  • Vasospastic angina/Prinzmetal angina
  • Silent ischaemia

Over time, CCS can cause ischaemic cardiomyopathy, leading to heart failure, or it can progress to ACS.

Epidemiology

Ischaemic heart disease is a leading cause of death in US and the world. Men are more commonly affected. There is a rising tendency in developing countries. IHD accounts for nearly 30% of all disability cases. It especially affects the middle aged population.

Risk factors

Classic risk factors:

• Male gender
• Older age
• High total or LDL cholesterol
• Hypertension
• Smoking
• Diabetes mellitus
• Family history
• Obesity
• Diet high in energy, low in vegetables, high in meat, high in fats, etc.

Non-classic (“new”) risk factors:

• Metabolic syndrome
• High inflammatory parameters (high CRP)
• Abnormal blood coagulation parameters
• Chronic renal disease
• Oxidative stress, air pollution
• Low socioeconomic status
• Mental ill health, psychological stress
• Alcohol abuse
• Hyperhomocysteinaemia

Diagnosis and evaluation

Cardiac CT can be useful in the evaluation of ischaemic heart disease. Coronary CT angiography is a non-invasive alternative to invasive coronary angiography, used for the diagnosis of coronary artery disease in those at low or intermediate pretest probability. Those with high pretest probability proceed directly to invasive coronary angiography, as this allows for percutaneous coronary intervention of any stenoses in the same setting.

Echocardiography is also important. It can detect wall motion abnormalities which can be signs of previous myocardial infarction.

Myocardial perfusion imaging (nuclear medicine myocardial perfusion studies) is another modality used for evaluation of ischaemic heart disease. It can detect regions of the myocardium which is hypoperfused during rest or activity.

Primary prevention

Screening asymptomatic healthy adults > 40 years with a risk-estimation system like SCORE is recommended. Healthy adults with first-degree relatives with premature (occurring earlier than normal) cardiovascular disease should also be screened.