Silent Myocardial Infarction and Diabetes Mellitus Type 2

Diabetes is regarded as a serious disorder that can lead to chronic micro- and macrovascular complications. Patients who are diagnosed with diabetes mellitus type 2 often die from silent myocardial infarction and heart failure. Glycemic control is usually associated with a positive effect and reduces microvascular complications, but the macrovascular benefits of this treatment are less certain. It is a general opinion that silent myocardial ischemia is highly prevalent in diabetes. The percentage of patients suffering from this complication has decreased over the last decade, but it remains crucial to review the pathophysiology, diagnosis, and treatment of silent myocardial infarction that comes as a result of diabetes mellitus type 2.

Patients with diabetes often exhibit microalbuminuria, which is associated with cardiovascular risk. Some researchers have noted that “patients with microalbuminuria had a higher prevalence of ischemic response (>1mm ST depression) (65% vs 40% p = 0.016)” (Dua & Anand, 2017, p. 1510). Silent myocardial ischemia is referred to as the presence of myocardial ischemia symptoms without angina equivalent and chest discomfort.

This disease is classified into three types. Silent myocardial ischemia type I is not a common form, and it occurs in patients who are fully asymptomatic and suffer from obstructive coronary artery disorder. Type II of silent ischemia occurs in individuals who have had previous myocardial infarcts. Silent ischemia type III is the most prevalent form, and its total burden can be both asymptomatic and symptomatic. It is believed that anginal pain cannot be regarded as a good indicator as most silent myocardial infarctions occur during an absence of physical exertion or are accompanied by a minimum of symptoms.

Silent myocardial infarction is associated with a high coronary risk and may result in sudden death. Coronary artery illness is known to be the main cause of mortality among patients with diabetes mellitus type 2. This disease can be diagnosed early and has an unfavorable prognosis in patients with diabetes. Researchers and practitioners generally recognize that cardiovascular autonomic neuropathy, a common and serious complication of diabetes, is able to provoke silent myocardial infarction by destroying the balance between myocardial demand and supply. Thus, affected patients may often report shortness of breath, fatigue, and diaphoresis. It is noted that information on silent myocardial infarction is very diverse and amounts from 62 to 12 percent in people with diabetes mellitus type 2.

A diagnostic test that is ideal for detecting silent myocardial ischemia in patients does not exist. Some researchers have noted that “the American Diabetes Association did not recommend routine screening for silent myocardial ischaemia in asymptomatic people as it does not improve outcomes as long as cardiovascular disease risk factors are treated” (Sultan et al., 2017, p. 1247). It has also been emphasized that detection of affected individuals with silent myocardial infarction is a challenge because many methods that are regarded as accurate rely on cardiovascular magnetic resonance (CMR) (Swoboda et al., 2016, p. 3316). These methods are recognized to be costly and time-consuming, as well as limited in availability. However, it has been noted that some biomarker and imaging tests can identify its presence. It has also been stated that “silent MI detected on CMR is associated with increased mortality and adverse cardiovascular events” (Swoboda et al., 2016, p. 3323).

Researchers have noted that episodes of silent ischemia can be reduced with the same pharmacological agents that are used for symptomatic ischemia. Such agents include beta-blockers, nitrates, and calcium antagonists. It is believed that increasing myocardial demand for oxygen is the primary reason for the occurrence of silent ischemia. Thus, beta-blockers and nitrate medications are necessary components of combination therapy. It has also been noted that revascularization might be helpful for improving patient outcomes in treating silent ischemia that appears as a complication of diabetes mellitus type 2.

Usually, medications applied to control insulin level in blood will also influence the decrease of silent myocardial infarction. Some researchers argue that Liraglutide, an analog of glucagon-like peptide 1 in humans, has shown fewer microvascular risks than other drugs that have been used previously (Marso et al., 2016). Thus, the more recent medications have been more effective for treating diabetes mellitus type 2 and preventing silent ischemia.

The given paper has dealt with the review of the pathophysiology, diagnosis, and treatment of silent myocardial infarction that comes as a result of diabetes mellitus type 2. The main factors that influence the occurrence of silent myocardial infarction in patients with diabetes were identified, and the screening methods and treatment opportunities were noted.

References

Dua, H. S., & Anand, M. (2017). The study of correlation of silent myocardial ischemia with microalbuminuria in patients of type 2 diabetes mellitus. International Journal of Advances in Medicine, 4(6), 1506-1512.

Marso, S. P., Daniels, G. H., Brown-Frandsen, K., Kristensen, P., Mann, J. F., Nauck, M. A., & Steinberg, W. M. (2016). Liraglutide and cardiovascular outcomes in type 2 diabetes. New England Journal of Medicine, 375(4), 311-322.

Sultan, A., Perriard, F., Macioce, V., Mariano‐Goulart, D., Boegner, C., Daures, J. P., & Avignon, A. (2017). Evolution of silent myocardial ischaemia prevalence and cardiovascular disease risk factor management in Type 2 diabetes over a 10‐year period: An observational study. Diabetic Medicine, 34(9), 1244-1251

Swoboda, P. P., McDiarmid, A. K., Erhayiem, B., Haaf, P., Kidambi, A., Fent, G. J., & Kearney, M. T. (2016). A novel and practical screening tool for the detection of silent myocardial infarction in patients with type 2 diabetes. The Journal of Clinical Endocrinology & Metabolism, 101(9), 3316-3323.