There is no single cause for coronary heart disease. There are controllable and non-controllable risk factors that can increase your chance of developing it.  

Coronary heart disease risk factors that you can change include:  

• Unhealthy eating  
• Being physically inactive 
• Being overweight or obese 
• Smoking – either being a smoker or inhaling other people’s smoke (passive smoking) 
• Diabetes 
• High blood pressure 
• High cholesterol 
• Lack of good social support. 

Coronary heart disease risk factors that you can’t change: 

• Family history of coronary heart disease 
• Getting older 
• Ethnicity – Māori, Pasifika people and those from South Asian countries are at higher risk of heart disease 
• Being male 
• Being a post-menopausal woman 
• Severe mental illness. 

Your doctor may suggest one of the below procedures. 

Angioplasty and stents 

Angioplasty uses a special balloon to widen a narrowed or blocked artery. This restores blood flow to the heart. During this procedure, the surgeon may put a small mesh tube called a stent into the artery to keep it open.

Coronary Artery Bypass Graft (CABG) Surgery 

Bypass surgery improves blood flow to the heart to treat angina. During the surgery, the cardiologist takes a blood vessel from another part of your body (usually your leg or arm) and uses it to make a new pathway for blood to flow around a blocked artery. 

Where to get help 

• Always dial Triple Zero (000) to call an ambulance in a medical emergency 
• See your GP and/or cardiologist  
• Ask your doctor, or hospital staff about a cardiac rehabilitation service. 

A large study published in the Journal of the American College of Cardiology demonstrated that coronary calcium scoring is a better predictor for heart disease risk compared to intra-venous coronary angiography. Coronary calcium scoring is less expensive, does not require an intra-venous injection, typically is lower radiation & does not have the potential for an anaphylactic reaction or kidney damage in certain cases. 

 Invasive Coronary Angiography

 This is an invasive test where a flexible catheter is introduced either through the artery in the wrist or the groin. It is considered the gold standard to detect & measure the extent & severity of blockages in the coronary arteries. As it is invasive, there is a small potential for risk & therefore should only be performed in patients with significant symptoms or tests that suggest serious lack of oxygen to the heart muscle.

Calcium Scoring

The best current method for determining the degree of coronary atherosclerosis, however, (and therefore coronary risk), is CT scanning of the coronary arteries, also known as coronary calcium scoring. Coronary calcium scoring provides an historical picture of the coronary arteries, which is a surrogate marker for the accumulation of fat in the arteries over the decades up to the point of scanning. The great value is that coronary calcium scoring is quantitative.

The scoring ranking is as follows:
Zero: lowest cardiac risk. (Predicted 10 year risk is only 1% which is much less than the majority of the population.)
1-10: trivial calcification
10 – 100: mild calcification
100 – 400: moderate calcification
> 400: severe calcification

A Calcium score > 400 predicts around a 50% ten year risk, which makes it a much stronger risk predictor than cholesterol levels, blood pressure, diabetes and cigarette smoking. The calcium itself is not the problem. In fact, calcium is used by the body as a strengthening agent. The commonest site for calcium is, of course, in the bones, to make the bones stronger. If the body detects an area of weakness, such as fat build up in the wall of the artery, it will send in calcium to act as a scaffold to make the artery stronger so it will not break down. Unfortunately, if you continue to bombard your arteries with modern living, the fat continues to build up in the wall and thus the calcium builds up attempting to stabilize the fat. Calcium is very easily seen and measured by a CT scanner and therefore is a very good marker for the degree of fat you have in your arteries. Let me also make the point that calcium in the arteries has nothing to do with the calcium you take in your diet or in supplement form and in fact there is now a very strong link between low Vitamin D levels (which is a very important controller of calcium metabolism) and a higher risk for heart disease. Coronary calcium scoring is low dose radiation, usually around 4-5 chest x-rays worth, and relatively inexpensive. It does not require any injections and its results are very reproducible.

The majority of people living in modern society should consider having a coronary calcium score at some stage in their middle age. For men, we suggest somewhere between 45-50 years old, for women 55-60 years.

The reason for the age difference is that women tend to lag ten years behind men in their coronary risk. This is usually because of the hormonal protection afforded by oestrogen and progesterone. When women commence menopause, their risk for heart disease significantly increases.