Diabetes and Heart Attack: Can We Catch It Before It’s Too Late?

Type 2 diabetes (also known as adult-onset diabetes and non-insulin-dependent diabetes) usually develops gradually in adulthood and is caused by delayed or impaired insulin secretion, impaired insulin action, or excessive glucose output by the liver. Now insulin is a hormone that regulates the amount of glucose (sugar) in the blood and is required for the body to function normally. Cells in the pancreas, called the islets of Langerhans, produce insulin. These cells continuously release a small amount of insulin into the body, but they release surges of the hormone in response to a rise in the blood glucose level. However this function is lost in diabetes. It is important for glucose to be under control as an elevated level results in diabetes and subsequent damage to the eyes, kidneys, feet and can even result in death if not treated.

The leading cause of type 2 diabetes is cardiovascular disease (CVD), the most common of which is a heart attack. Yet the problem for us lies in detecting those patients with type 2 diabetes that are actually at high risk of having a heart attack. In a recent trial published by ‘The Danish Diabetes Association’ and ‘The Danish Heart Foundation’ efforts were made to try and identify a system whereby this was achievable. They had a look at how common heart attacks were in patients with type 2 diabetes and tried to establish an algorithm to identify the ‘at risk’ patients.

Methods included referring patients with type 2 diabetes and no known or suspected CVD to the diabetes clinic for the first time. Here they were categorized based on traditional risk factors for heart attack. These included; chest pain, obesity, blood pressure, blood sugar level, cardiac enzyme markers (for indication of damage to the heart muscle), output of blood from the heart and presence of disease in the arteries in the legs or neck.

With the information above an algorithm was created to stratify patient risk according to low, medium and high risk. All patients were then given a myocardial perfusion scintigraphy scan (MPS) which is basically just a fancy machine that detects if there has been any previous damage to the heart. Information gained from this scan therefore showed if all patients had been categorized to the correct group or not. The results of this showed that the algorithm was able to stratify which patients had a low, intermediate or high risk of heart attack based on MPS. However, the algorithm had low sensitivity and specificity, which means that some will be put in the high risk group when they are low or intermediate risk and vice versa. This algorithm is also associated with high cost and time requirements. However this is only the first attempt and no doubt with further research the algorithm will become more and more effective, watch this space!!!