Researchers in Bristol have found that hearts may develop innate protection against further damage after coronary disease.

However, the same study has also shown that western-style high fat diets can significantly weaken this internal defence of the organ.

Saadeh Suleiman, Professor of Cardiac Physiology at the University of Bristol, and his colleagues at the Bristol Heart Institute modified the apoE gene in mice, which changed their cholesterol processing and made the rodents prone to fatty build-up in the coronary arteries, similar to human heart disease.

Thereafter, the genetically modified mice were fed a high-fat diet that is typically consumed by people in North America and the UK, causing them to develop coronary artery disease and suffer heart attack. On the other hand, mice fed a normal rodent diet for the same period did not develop coronary disease.

The researchers say that coronary disease seemed to have “preconditioned” the hearts, that is, it caused them to develop an innate protection against further damage.

According to them, this finding confirms a widely held belief that in certain heart attack survivors, the heart may become naturally preconditioned against further damage, and that when treating patients with coronary disease, surgeons and cardiologists have an advantage that can be further exploited to protect the heart.

The researchers also observed that though normal mice do not develop coronary disease upon being fed the same Western-type high-fat diet, they were much more vulnerable to injury than rodents fed normal diet in case their hearts were starved of blood supply, as happens in a heart attack of during surgery.