ATLANTA — Women with acute MI are roughly one-third less likely than are men to undergo cardiac catheterization and coronary revascularization procedures, a trend that has persisted since the mid-1980s, William J. Kostis, Ph.D., said at the annual meeting of the American College of Cardiology.
Similarly, African Americans with an MI—men as well as women—are roughly one-quarter less likely than are whites to get a revascularization procedure. And again, that trend has held constant since the mid-1980s, said Dr. Kostis of Robert Wood Johnson Medical School, Piscataway, N.J.
These were among the provocative findings of an analysis of nearly 248,000 first MIs in New Jersey during 1986–2002. The data were collected through the state's Myocardial Infarction Data Acquisition System (MIDAS), which includes information on all patients admitted with acute MI to nonfederal hospitals in New Jersey.
Since this is a nonselected patient population, it seems highly likely that the observed trends regarding gender and racial disparities in invasive cardiac procedures are generalizable to the rest of the country, he said. Lower rates of invasive procedures in women and African Americans have been reported previously in several other studies. Where MIDAS breaks new ground is in providing a picture of trends over a lengthy 17-year period.
MIDAS documented a marked increase in cardiac catheterization in MI patients during the study period. Among men, the rate climbed from 23% in 1986 to 70% in 2002. In women, it rose from 13% to 52%.
The rate of revascularization by percutaneous coronary intervention or coronary artery bypass surgery was less than 10% in both men and women with acute MI in 1986. In men, the rate climbed steadily to 54% by 2002, but in women it reached 34% in the mid-1990s and then leveled off.
Both African Americans and whites with acute MI underwent cardiac catheterization about 20% of the time in 1986. The rates of the diagnostic procedure rose comparably in the two racial groups over time.
Coronary revascularization, however, was a different story. The revascularization rate was less than 10% in both groups in 1986, but by 2002 it rose to 46% among whites, and to 38% in African Americans, Dr. Kostis continued.
To learn whether these differences in procedure rates influence clinical outcome, Dr. Kostis and coinvestigators looked at 30-day mortality following a first MI, adjusting for age, comorbid conditions, site and severity of MI, and complications during hospitalization. Adjusted mortality was significantly greater in women than in men, and in African Americans than in whites.
But after further adjustment for rates of invasive cardiac procedures, the increased mortality risk in women and African Americans was diminished; it became statistically nonsignificant in African Americans. This implies the lesser use of procedures in these groups is causally related to their higher mortality, he said.
Dr. Kostis said that he plans next to look at the impact of disparities in procedure rates on longer-term mortality.