Diabetics with heart problems have always remained a challenge to physicians. They may present in a most atypical manner. They may have severe coronary heart disease (CHD) and yet remain without symptoms of chest pain – referred to as a "silent ischemia." They may even have a heart attack without the usual severe chest discomfort ("silent heart attack"). Many of these diabetic health patients may die suddenly without reaching the hospital.
Treatment of the diabetic heart patient is also more complicated than it seems. A more comprehensive treatment regimen not simply operating on the known principles of the circulation (as exemplified by commonly used hemodynamic drugs) is necessary.
Scientific evidence in the last five years recommends a class of drugs called "metabolic modulators" as an alternative treatment for CHD which has emerged as a leading killer in our country. These drugs relieve chest pain (angina) and improve exercise and effort capacity, thus, allowing heart patients to resume their usual daily activities, with rare side-effects. Diabetics are a group of patients at high risk of developing coronary heart disease, and metabolic modulators may play a role in their treatment.
Coronary heart disease refers to the narrowing of the blood vessels supplying the heart muscle, by way of a process called atherosclerosis. This results in chest pains and discomfort usually during physical exertion. Diabetes is defined as abnormally elevated levels of blood glucose (a form of sugar), associated with various other abnormalities within the body that lead to damage of vital organs, including the blood vessels, nerves, heart, brain, kidneys and eyes.
The combination of diabetes and coronary heart disease is quite dangerous. Diabetics have more than double the risk of developing CHD, and nearly triple the risk of dying due to heart disease, compared to non-diabetics. Things get worse when these patients develop heart attacks, since the incidence and severity of complications become even greater in diabetics. In fact, diabetics who have had heart attacks have twice the mortality and triple the rate of progression to heart failure compared to non-diabetics.
Scientific studies have identified several reasons why diabetes aggravates CHD. Diabetes accelerates the process known as atherosclerosis, resulting in more extensive, diffused and severe blockages of the blood vessels supplying the heart muscle. Diabetes also causes the deposition of abnormal chemicals within the heart muscle itself, thus, weakening it (called diabetic cardiomyopthy), eventually leading to heart failure. Diabetes also makes the blood more sticky and prone to clotting, which may totally block blood vessels and thus, cause a heart attack. Finally, diabetes may shift the heart’s energy source away from glucose to the use of oxygen-consuming fatty acids, aggravating the lack of blood, nutrients and oxygen even further.
While a detailed discussion of the management of the diabetic coronary patient is far beyond the scope of this article, these few important points may help as a guide in the management of these patients:
• Due to nerve damage, diabetics may not experience the typical chest pain usually felt with blocked blood vessels, thus, delaying consultation and treatment. These patients may have to consult a heart specialist for special test to diagnose coronary heart disease.
• The latest scientific studies have shown that good control of blood sugar levels in diabetics result in a very significant reduction in complications, including heart disease. This means that diabetics should religiously comply with their diet, exercise and drug regimens as prescribed by their attending physicians.
• Risk factors for coronary heart disease, including obesity, high levels of blood cholesterol and other fatty substances, high blood pressure, and cigarette smoking should be vigorously managed.
• Medical therapy for chest pain due to coronary heart disease in diabetics is similar to that in non-diabetics. However, it must be noted that conventional hemodynamic drugs may aggravate typical diabetic complications, including erectile dysfunction (impotence), gastrointestinal dysfunction, heart failure, and even blood sugar control itself. Due to their favorable actions in shifting the heart’s fuel back to oxygen-conserving glucose (instead of oxygen-requiring fatty acids), and due to their rare side-effects, metabolic modulators like the drug Trimetazidine (Vastarel) have been effectively and safely used in diabetic coronary patients, especially when conventional agents are poorly tolerated or are insufficient.
• Should more aggressive therapy be required in diabetics, coronary artery bypass surgery has been shown to be clearly superior to angioplasty, a procedure where the blocked blood vessels are dilated by an inflated balloon inserted through the groin.
In conclusion, the incidence of both diabetes and coronary artery disease is on the rise in the Philippines, and we expect to see an increasing number of patients where these two diseases co-exist. Diabetic coronary patients require expert and special care, so they may continue living happy and productive lives.
(The author is a past president of the Philippine Heart Association, Philippine College of Physicians and medical director of the Philippine Heart Center. She is currently the vice president of the Philippine Society of Hypertension and the Philippine Lipid Society, and a member of the Advisory Board of CHARTER, a non-stock, non-profit research foundation based at the Manila Sanitarium Hospital.)