CAP TODAY Pathology/Laboratory Medicine/Laboratory Management
Karen Lusky
June 2016—Robert Christenson, PhD, a professor of pathology and of medical and research technology at the University of Maryland School of Medicine, likens the U.S. mortality rate for myocardial infarction to three or four jumbo jets crashing daily. For heart failure, it’s about half that many deaths, “so maybe one and one-half jumbo jets,” Dr. Christenson said in a session on cardiac biomarkers at the CAP annual meeting last year.
Dr. Christenson
With more people living longer in general but surviving acute MI, said co-presenter and cardiologist Christopher deFilippi, MD, “we are seeing a marked increase in the number of hospitalizations and the incidence of heart failure in the population.”
Heart failure has moved front and center, too, because of its high readmission rate—about 25 percent within 30 days of discharge as of a couple of years ago, said Dr. deFilippi, vice chair of academic affairs at Inova Heart and Vascular Institute in Fairfax, Va. Yet only about a third of those readmissions are due to heart failure. “These patients have a huge number of comorbidities that can influence a variety of biomarkers,” he noted.
The 2015 approval of the Novartis drug Entresto has brought more attention. Dr. Christenson, Dr. deFilippi, and others talked with CAP TODAY recently about the questions Entresto has raised, and about the conventional and less conventional heart failure biomarkers.
Dr. deFilippi
Entresto, approved for patients with heart failure and reduced ejection fraction, is a chemically bound compound of valsartan, which is a well-known angiotensin receptor blocker, and sacubitril, a neprilysin inhibitor that blocks the breakdown of BNP.
Brian Lund, MT(ASCP), of Alere, which manufactures BNP and NT-proBNP assays (the latter not sold in the U.S.), says that in Novartis’ clinical trial for Entresto, called PARADIGM-HF, the natriuretic peptides showed an “interesting pattern” over the three time points when they were measured. Initially, a small rise in BNP was seen followed by a steady decrease over the next eight months, he says. “In contrast, NT-proBNP showed a small decline initially and a continued decline at the remaining time points similar to that observed for BNP. There are theories on why this pattern emerges, but more work needs to be done,” says Lund, who is global product director in the cardiometabolic business unit in the Waltham, Mass.-based company. (Alere’s assays were not used in PARADIGM-HF.)
Entresto hasn’t had a major uptake in the United States because of its cost and insurance companies’ reluctance to cover it, says cardiologist Allan Jaffe, MD, a professor of medicine and cardiology and of laboratory medicine and pathology at Mayo Clinic in Rochester, Minn. “We do use that particular agent, and given the data in regard to outcomes, its use should increase.”