Interferon shows hope for chronic viral cardiomyopathy
NEW ORLEANS—Giving interferon to heart failure patients with evidence of a chronic viral infection safely eliminated two viruses from their systems and reduced levels of a third virus, according to a late-breaking clinical trial presented Tuesday at the American Heart Association (AHA) Scientific Sessions.

Lead author Heinz Peter Schultheiss, MD, from the department of cardiology and pneumology at Charite – University Medicine of Berlin in Germany, who presented the randomized trial, said that the results “provide the first evidence that interferon beta-1b (IFN_-1b) treatment eliminates cardiotropic viruses and may improve the clinical outcomes of patients with chronic enteroviral and adenoviral heart disease.”

The double-blind Phase II study included 143 patients at 31 medical centers in seven European countries, and found that there were trends toward improved cardiac function and quality of life, but these did not reach significance at 24 weeks.

Schultheiss reported that viral load for parvovirus was reduced, but no evidence for elimination. They found that patients infected with adenovirus, enterovirus and/or parvovirus B19 who received IFN_-1b were about twice as likely to have improved symptoms 12 weeks after treatment ended.

He also said that they found that 38.6 percent of the interferon patients had an improved New York Heart Association (NYHA) functional classification as compared to 18.6 percent of those in the placebo group at 12 weeks. However, by the week 24, the placebo group had improved slightly and the difference between groups was not statistically significant.

Schultheiss said the quality of life score, as measured by the Minnesota Living with Heart Failure Questionnaire, improved continuously during treatment, and was more pronounced in the enterovirus/adenovirus subgroup than in the subgroup with parvovirus. The findings also fell short of statistical significance when compared with placebo.

The primary endpoint was the absence of adenovirus, enterovirus and parvovirus in biopsies taken an average of 12 weeks after treatment ended. For the parvovirus group, virus elimination was assessed with a quantitative assay. Schultheiss said IFN_-1b resulted in clearance of all enteroviruses and adenoviruses, but noted that parvovirus persisted in some of the double infected patients.

According to this primary endpoint, only patients with complete clearance of both viruses were calculated as responders. This resulted in clearance rates of 40 and 50 percent in the chronic adenovirus-enterovirus group, depending on the dose, and clearance or reduction rates of 31.8 to 35.7 percent in the parvovirus group, Schultheiss said.

Schultheiss concluded that these data implicate, for the first time a biopsy-based specific and causal therapy for chronic viral cardiomyopathy. However, he noted that final confirmation including prognosis requires a phase III trial.