Posted on November 17, 2005 at 10:45 a.m.
DALLAS — An experimental drug belonging to a new pharmacological class called calcium sensitizers holds promise for the 1 to 3 million Americans hospitalized annually for worsening symptoms of heart failure.
A study involving the University of Alabama at Birmingham (UAB), presented during a late-breaking clinical trials session at the annual meeting of the American Heart Association November 14, showed that hospitalized heart failure patients who received the new drug, called levosimendan, in addition to standard treatment, had a greater likelihood of clinical improvement and a lower risk of clinical deterioration than those who only received standard therapy.
Results of the REVIVE II (Randomized Multicenter Evaluation of Intravenous Levosimendan Efficacy) study, which tested levosimendan and evaluated its effects on the clinical course of patients with acutely decompensated heart failure during an average hospital stay, were presented by lead author Milton Packer, M.D., of the University of Texas Southwestern Medical Center in Dallas.
UAB was the second largest enroller of the clinical trial nationwide, and UAB lead investigator Robert C. Bourge, M.D., said all of the REVIVE II investigators are pleased with the outcomes. “Based on early studies of this drug, the results are very encouraging, as therapy with levosimendan seemed to improve symptoms in patients with severe heart failure significantly more than conventional therapy alone,” Bourge said. “However, further analysis of the potential side effects of the drug will need to be reviewed in more detail.” He added that the drug is already approved in other countries.
Levosimendan and drugs in the calcium sensitizer class work in a unique way and combine the actions of both inotropic agents and vasodilators. Inotropic agents help the heart beat more forcefully; vasodilators help blood vessels dilate, so more blood can get to the body’s organs with each beat of the heart.
Levosimendan increases the sensitivity of heart cells to calcium. The binding of calcium to proteins in heart cells triggers the heart’s contraction. Most current inotropic agents increase the amount of calcium in the cells. This increase strengthens the heartbeat but carries a risk of having too much calcium in the cells. In contrast, levosimendan makes optimal use of the calcium already present in the cells rather than increasing it.
Six hundred heart failure patients were enrolled at hospitals in the United States, Australia and Israel. Bourge said the results showed the likelihood of clinical improvement was 33 percent higher, and the risks of clinical deterioration were nearly 30 percent lower in patients who received levosimendan in addition to standard therapy compared with those who received only standard therapy. The study was funded by the drug’s manufacturers, Abbott Laboratories and the Orion Corporation.
Bourge said it is estimated that in 2005, hospital costs for congestive heart failure will total $14.7 billion in the U.S. alone, with approximately two-thirds of that cost directly associated with the number of days patients spend in the hospital.