The long-term fate of heart disease patients may be made a bit clearer by a simple blood test. Heart disease is a leading killer of men and women in the U.S., and the blood test could reveal which patients are most vulnerable.
The test checks blood levels of a hormone called B-type natriuretic peptide (search) (BNP). Blood tests for BNP are already used to screen for heart failure, since elevated levels of the hormone indicate that the heart muscle is stressed and the patient is at a high risk of death.
Now, researchers say that high BNP levels may also predict heart disease (search) death in people with coronary artery disease, without heart failure. The study shows that this measure predicts heart disease death beyond traditional heart disease risks factors.
The news appears in The New England Journal of Medicine’s Feb. 17 edition.
Barely a year ago, the journal published a preliminary report suggesting that BNP levels considered normal might actually predict various heart problems, including heart failure, death, irregular heartbeat, and stroke.
Now, Danish researchers report more news about BNP. They followed 1,034 people for an average of 9 years. All participants had shown signs of coronary artery disease and angina (chest pain due to not enough oxygen being received by the heart muscles). However, none of the patients had heart failure.
The participants had been told by their doctors to get angiography.
In angiography (search) a dye is injected into the patient while heart images show how blocked the arteries of the heart are. It helps diagnose coronary artery disease.
Besides angiography, participants had BNP blood tests and provided thorough medical histories. Red flags for future heart trouble included well-known risk factors such as previous heart attacks or strokes, chest pain, suspected heart failure, diabetes, smoking status, and cholesterol levels.
By the end of the study, 288 participants had died. They had significantly higher BNP levels than surviving participants.
Those with the highest BNP levels were also older and more likely to have a history of heart attack, poorer heart function, more blocked heart arteries, and diabetes.
BNP was “a strong predictor of mortality,” say the researchers, who included Charlotte Kragelund, MD, of the cardiology and endocrinology department at Denmark’s Frederiksberg Hospital.
BNP also added predictive information beyond what conventional risk factors showed, say Kragelund and colleagues. Those risk factors included age, gender, family history of heart disease, previous heart attacks, high blood pressure, diabetes, chronic heart failure, body mass index, smoking, blood fats, and coronary artery disease.
If confirmed, the findings could help doctors assess patients’ risk and tailor treatment to their needs, say the researchers.
Likewise, last year’s report and related editorial also concluded that BNP needs more study before action could be taken. For now, high BNP levels look like all-around bad news for the heart, but more work must be done to find the best response.
SOURCES: Kragelund, C. The New England Journal of Medicine, Feb. 17, 2005; vol 352: pp 666-675. WebMD Medical News: “Hormone May Be New Marker of Heart Disease.” WebMD Medical Reference from Healthwise: “Angiography.”