Roche, leading research-oriented healthcare groups, reported that it has received FDA clearance for its Elecsys proBNP (pro-B-type natriuretic peptide) assay, the first fully automated test for use in the diagnosis of congestive heart failure (CHF).

Now, laboratories can have results ready to report to physicians in as few as 18 minutes, using an automated platform that reduces technologist time and minimizes human errors. Just as important, the Elecsys proBNP assay gives the physician an accurate reading of elevated NT-proBNP due to CHF without interference from certain drug therapies."Elecsys proBNP meets the need for a reliable diagnostic test for use in the early detection and treatment of congestive heart failure," says Heino von Prondzynski, Head of Roche Diagnostics and a member of Roche's corporate executive committee.

B-type natriuretic peptide (BNP) is secreted by the left ventricle when the heart is unable to pump blood efficiently. BNP dilates blood vessels and promotes sodium and water loss, reducing fluid load on the heart and improving cardiac performance. Synthetic BNP, marketed as Natrecor (nesiritide), is a treatment for heart failure. Thus, measuring BNP does not necessarily allow the physician to differentiate between elevated BNP levels due to drug treatment and elevated BNP due to ventricular dysfunction.

By contrast, the Elecsys proBNP assay measures N-terminal proBNP (NT-proBNP), which is released when BNP is cleaved from its precursor, proBNP. Elevated plasma NT-proBNP indicates the presence of heart failure and provides information about its severity: the higher the blood level of NT-proBNP, the more serious the condition. NT-proBNP levels have been demonstrated to be a diagnostic aid in identifying left ventricular dysfunction, allowing physicians to differentiate between heart failure and lung disorders with similar symptoms.

According to the American Heart Association, 4.8 million Americans are afflicted with CHF, with 550,000 cases diagnosed each year. CHF is only one of the causes of heart failure; other causes are age, hypertension, cardiomyopathy, or valve defects. Significantly, heart failure is the leading cause of Medicare hospitalization in the U.S., accounting for 18 billion dollar per year in direct costs. Prevalence of heart failure is expected to continue to rise, due to the aging population and increase in acute coronary syndrome survival. Heart failure is often difficult to diagnose, since its symptoms are nonspecific and are sometimes confused with those of other conditions such as chronic obstructive pulmonary disease.

Echocardiography, the gold standard for diagnosis of left ventricular dysfunction, is expensive and not always easily accessible. The Elecsys proBNP assay is available in Europe since 2002 and is planned to be launched in Japan next year. In Europe two per cent of the people are supposed to have CHF. In the age of over 70 this increases to more than 10 per cent.