Oct. 26 (HealthDay News) -- A type of drug called human atrial natriuretic peptide (ANP) can lessen cardiac injuries after heart attack and boost patient outcomes, a new study finds.

According to a Japanese study in this week's issue of The Lancet, use of the drug reduced the extent of damaged heart muscle (infarct) and lessened what's known as "reperfusion injuries," caused when blood rushes back to the heart.

The Japanese study included 277 acute heart attack patients who received intravenous ANP for three days and 292 patients who received the same dose of a placebo.

After a median follow-up of 2.7 years, infarct size was 15 percent less and left-ventricular ejection fraction (LVEF) was 5 percent higher in patients who received ANP, compared to those who were given the placebo.

LVEF is a measurement of the heart's pumping ability.

"We need to do another large-scale clinical trial to target clinical outcomes such as cardiovascular death, because our primary aim here was to test the reduction of infarct size," researchers at the National Cardiovascular Centre Suita, in Osaka, said in a statement.

"Our finding that treatment with ANP in the acute phase reduced the incidence or readmission to hospital for chronic heart failure could help to reduce the physical, medical, and economic burdens on people around the world," they concluded.

SOURCE: The Lancet, news release, Oct. 26, 2007