In other words, their 'bad' LDL (low-density lipoprotein) levels were normal, and wouldn't have been a warning sign of heart disease. Instead, heart disease is as likely to be caused by smoking or a bad diet, say researchers from the Minneapolis Heart Institute.
The 1,062 patients they analysed had all survived a STEMI (ST-Elevation Myocardial Infarction) heart attack, one of the most serious kinds that happens when a major artery becomes blocked. It's usually the result of atherosclerosis, or hardening of the arteries, which is supposed to happen when LDL cholesterol levels are high and start attaching to the artery wall until it's blocked.
"Heart disease is a multi-factorial process and factors other than cholesterol can raise your risk, even if your cholesterol is normal. In fact, we found that the average cholesterol level in this group of individuals were quite average," said lead researcher Michael Miedema.
Despite having normal cholesterol levels, 79 per cent of the group met the new and tougher guidelines for starting statin therapy, whereas just 39 per cent would have done so under previous guidance.