Self-reported diagnosis of heart disease: Less than one in five heart problems are diagnosed before symptoms appear

May 11 2009

Clinicians are missing golden opportunities to identify heart disease before patients start displaying symptoms, according to a study of 13,877 people published in the May issue of UK based IJCP.

Researchers from Oregon, Maryland and Delaware, USA, found that just over 11% of the respondents had been diagnosed with heart disease. However, only 19% of those individuals - who had been involved in the ongoing study for two years - said that their heart disease was picked up during routine screening.

More than half of the diabetic patients with heart disease who took part in the study (54%) reported that their heart disease was diagnosed when they became symptomatic and a further 22% said it was picked up while they were being treated for other health issues.

The figures were lower for individuals without diabetes. Just under half (48%) were diagnosed with heart disease when they became symptomatic and 15% were picked up during treatment for other conditions.

"Our study showed that not enough patients with heart disease are being picked up during routine screening or treatment for conditions like diabetes, which are commonly associated with heart problems" says lead author Dr Sandra J Lewis from the Northwest Cardiovascular Institute in Portland, Oregon. "The majority of those who took part in the study were not diagnosed until they started displaying symptoms."

Coronary heart disease (CHD) is the leading cause of death in the United States, accounting for more than 450,000 deaths a year. Approximately 15.8 million Americans who are 20 or older suffer from the disease.

"Many individuals do not show symptoms and go undiagnosed until the disease is in an advanced state, often when they have actually had a heart attack" explains Dr Lewis.

"That is why it is so important to diagnose CHD before patients experience their first crisis, by looking at major risk factors such as smoking, having high blood cholesterol, having high blood pressure, being overweight, being physically inactive or just getting older.

"Guidelines recommend that all adults over the age of 20 should receive risk factor screening from their family doctor every two to five years. There are more specific guidelines for patients with type 2 diabetes as their risk of a heart attack is twice as high as the general population."

The analysis from the SHIELD study (Study to Help Improve Early evaluation and management of risk factor Leading to Diabetes) was performed to see if ongoing recommendations for improved screening in the USA were resulting in more patients being diagnosed with heart disease before they became symptomatic.

It forms part of the larger SHIELD survey of 211,097 US households who responded to a national questionnaire.

More than 18,400 people who had participated in the baseline and first follow-up SHIELD surveys - and had diabetes or one of the five cardiometabolic risk factors - were sent questionnaires and 13,877 (75%) responded. Of these, 1,573 (11% of the total) had been diagnosed with heart disease.

Just under two-thirds had heart disease on its own (62%). They were predominantly male (59%) and white (91%) with an average age of 67. The remaining 38% had heart disease and type 2 diabetes. They were slightly more likely to be women (50.7%), 88% were white and their average age was 69.

The average time since diagnosis was 11.7 years in CHD patients without diabetes and 10.7 years in individuals with diabetes and CHD. Almost a third of the non diabetes group (31%) and 36% of the diabetes group had been diagnosed since 2001 when a number of consensus statements and guidelines on screening and prevention were published.

"Despite increased knowledge and awareness of the risk factors for CHD, many individuals are not diagnosed with heart disease until they are symptomatic" concludes co-author Dr Kathleen Fox from Strategic Healthcare Solutions in Monkton, Maryland.

"The fact that only a small percentage of the SHIELD respondents were diagnosed through screening indicates that there is a missed opportunity to diagnose heart disease during earlier, less severe stages of the disease.

"As blood pressure and weight are evaluated when most patients visit their family doctor, medical providers already have information about two key modifiable risk factors.

"Our study demonstrates the need for improved targeted education aimed at both patients and doctors to reduce heart disease before symptoms occur."