May 8 (HealthDay News) -- Black Americans are more likely than any other racial group to suffer serious complications after angioplasty and stenting and to require repeat procedures, but the reasons for these worse outcomes aren't clear.

That's the finding of a study that included 1,410 patients, average age 57, who had a percutaneous coronary intervention (PCI) procedure at Cook County Hospital in Chicago and were followed for an average of 1.7 years.

Gender and race-based analyses revealed that men and women were equally likely to experience a major adverse cardiac event -- such as heart attack, death or urgent need for a repeat procedure -- during the follow-up period, according to a Society for Cardiovascular Angiography and Interventions (SCAI) news release.

The study also found that the likelihood of survival without experiencing a major adverse cardiac event was 78.8 percent in black patients and 85.9 percent in all other patients.

"We need to be vigilant about evaluating and controlling all risk factors in this vulnerable population of patients," Dr. Sandeep Nathan, an assistant professor of medicine and director of the interventional cardiology fellowship program at the University of Chicago Medical Center, said in the news release. "Despite our best efforts to provide optimal care to all patients, we need to ask, 'What's missing?'"

The study was presented Friday at the SCAI's annual scientific sessions, in Las Vegas.

Nathan and colleagues are trying to pinpoint the reasons for this disparity in outcomes and suggested several possible explanations. One important cause may be lack of adherence to prescribed medications. Another key factor may be that black patients wait longer before seeking treatment, which means they're more likely to have advanced coronary disease when they undergo PCI.

SOURCE: Society for Cardiovascular Angiography and Interventions, news release, May 8, 2009