Issue 171 Item 13 Heart Defects Seen in Diabetes Patients Before Symptoms Occur

Patients with diabetes may have cardiac defects that put them at risk of a heart attack — even before they show any symptoms, according to a poster presentation at the 18th International Diabetes Foundation Congress.

"If we can find evidence of heart abnormalities earlier, we may be able to treat these patients earlier as well," says, Ines Thrainsdottir, MD, from the Karolinska Hospital in Stockholm, Sweden..

Dr. Thrainsdottir and colleagues enrolled 77 subjects in the study. Of the group, 43 were patients with type 2 diabetes. The average age was 61 years, and about two thirds were men and had a left ventricular ejection fraction of 57%. The control group was 34 participants without diabetes with an average age of 58 years, of whom about 62% were men. These control patients also had an ejection fraction of 57%, indicating normal heart function.

Patients underwent tissue Doppler imaging using typical office-based ultrasound devices. The ultrasound test recorded myocardial regional velocities from six areas of the heart while the patients were at rest or undergoing heart stress examinations.

"One of the advantages of doing tissue Doppler imaging," Dr. Thrainsdottir said, "is that you can record the tests and then analyze them later off-line."

The researchers found significant differences in systolic, early diastolic, and late diastolic velocities of the patients who already had the diagnosis of diabetes but without clinical symptoms of heart failure. "Patients with diabetes had higher systolic blood pressure and pulse pressure at rest and when undergoing dipyridamole stress," she reported to meeting attendees.

"Diastolic and systolic myocardial dysfunction was identified by quantitative tissue Doppler imaging before the onset of clinical signs of heart failure and appearance of traditional echocardiographic indices of dysfunction," she said.

Eva Toft, MD, a physician at Ersta Hospital in Stockholm, stat that "This is what is so serious about type 2 diabetes." "These patients may already have cardiac damage even before they are diagnosed [with heart disease]."

It’s not surprising that patients with type 2 diabetes, presumably people who had been developing the disease for several years prior to being diagnosed, had some heart dysfunction, said Derek Stocker, MD, assistant professor of medicine at the Uniformed Services University of Health Sciences in Bethesda, Maryland.

"However, we don’t know from this study if the dysfunction that is being seen is important enough to treat people differently than we do now — with antidiabetes medicine, cholesterol-lowering agents, and blood pressure lowering drugs," he said.

Dr. Stocker said he wasn’t sure if the conditions warranted ultrasound studies on patients with type 2 diabetes or whether those patients who had no symptoms of heart failure but who showed ultrasound abnormalities in velocity flow needed to receive treatment, since most of these agents can have uncomfortable adverse effects.

In the study abstract, Dr. Thrainsdottir suggested that while tissue Doppler imaging could become a useful tool in detecting early heart abnormalities, another possible use of the device might be "to use it in pharmacological studies aimed at preventing diabetic cardiomyopathy."

Amanda Adler, MD, a clinician and epidemiologist at Oxford University in the U.K , said that "We would like to see this type of study carried forward prospectively to determine if these early abnormalities have clinical significance later on."

Dr. Thrainsdottir said that if the devices are found to be useful, performing ultrasound tests on patients who show early glucose resistance might determine if those heart abnormalities begin to occur before a diagnosis of diabetes is made. 18th IDF Congress: Abstract 1038. Presented Aug. 27, 2003.

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