The number of procedures used to unclog cardiac arteries has increased in New York State, even as mortality rates connected to the procedure are down, according to state health officials.

There were 56,058 angioplasties in 2005, up from 51,039 in 2004, according to new data from the state’s Department of Health, and mortality rates dropped to 0.88% in 2005 from 0.93% in 2004.

Health officials attributed both trends to advances in medical technology. Angioplasties are performed using a catheter, and the procedure, which requires a small incision in a patient’s groin or elbow, also results in shorter hospital stays than bypass surgeries.

Among hospitals, state health officials reported that NewYork-Presbyterian Hospital performed the most angioplasties, 4,604 procedures in 2005. The risk-adjusted mortality rate at the hospital’s Columbia University Medical Center in Washington Heights was 0.77%. At the hospital’s Weill Cornell Medical Center campus on the Upper East Side, the risk-adjusted mortality rate was 0.53%.

Health officials said the mortality rate at Brooklyn’s Maimonides Medical Center, 1.39%, was “significantly” higher than the statewide average. In 2005, the hospital performed 1,559 angioplasties. In a statement, a spokeswoman for the hospital said the 2005 data shows a “clustering” of adverse events. Between 2003 and 2005, the hospital had an 0.59% mortality rate for nonemergency cases, “evidence that the previous two years had better-than-average statistics,” the spokeswoman said. The data for 2006 and 2007, when published, will reflect a “return to baseline,” she said.

The Department of Health has publicized the outcomes of certain cardiac procedures, including angioplasties, for 10 years in an effort to improve quality. In 1995, there were 21,707 angioplasties with a mortality rate of 1.86%. In 2005, there were 49,492 nonemergency angioplasties, with a mortality rate of 0.60%.