Acute Reperfusion for STEMI Still Has Inappropriate Gaps

NEW HAVEN, Conn., Aug. 3 -- A sizable proportion of patients with ST-elevation myocardial infarction is still getting short shrift on acute reperfusion therapy, according to researchers here.

Although more STEMI patients are being appropriately treated than a decade ago, nearly 12% ideally suited for fibrinolytic therapy or percutaneous coronary intervention don't get either, found Harlan M. Krumholz, M.D., SM, of Yale, and colleagues.

The chance of not getting such therapy was highest among those without chest pain, those who didn't get to hospital before six hours after the onset of symptoms, women, patients over 75, and non-white patients, Dr. Krumholz and colleagues reported in the August issue of the American Journal of Medicine.

"This study has good and bad news," said Dr. Krumholz.

"We have definitely made progress in treating appropriate patients," he said, "but our findings indicate that we need to improve further to be sure that no patient who could benefit from this treatment is missed."

The findings emerged from an analysis of patient data in the National Registry of Myocardial Infarction between June, 1994 and May, 2003. The researchers divided the decade into three time periods -- June 1994 to May 1997; June 1997 to May 2000; and June 2000 to May 2003 -- to allow them to estimate trends.

Dr. Krumholz and colleagues found that the hospitals participating in the registry over that time had 238,291 with a STEMI who would have been ideal candidates for fibrinolytic therapy or percutaneous coronary intervention.

From 1994 through 2003, they found that 34,701 (14.6%) did not get either form of acute reperfusion therapy. On the other hand, the proportion of patients who didn't get treated appropriately dropped significantly.

"We found substantial improvement in the use of acute reperfusion therapy among ideal patients with STEMI between 1994 and 2003 in the U.S.," they wrote. "Most of this improvement appeared to occur during the late 1990s and has leveled off over recent years." During the earliest period, 20.6% of patients went untreated, the rate was 11.4% in the middle period, and it was 11.6% in the latest period.

Across all three periods, the trend was significant at P<0.001.

But the researchers also found that some key subgroups were significantly less likely to get treatment:

• Those without chest pain were 71% less likely to get acute reperfusion therapy. The odds ratio was 0.29 with a 95% confidence interval from 0.27 to 0.32.
• Patients presenting six to 12 hours after symptom onset were 43% less likely to get treatment. The odds ratio was 0.57 with a 95% confidence interval from 0.52 to 0.61.
• Patients 75 years or older were 37% less likely to get treated than patients 55 years old. The odds ratio was 0.63 with a 95% confidence interval from 0.58 to 0.68.
• Women were 12% less likely to get treatment. The odds ratio was 0.88 with a 95% confidence interval from 0.84 to 0.93.
• Non-whites were 10% less likely to get treated. The odds ratio was 0.90 with a 95% confidence interval from 0.93 to 0.97.

One of the study's strengths is the large sample size, the researchers noted. On the other hand, because not all hospitals participate in the registry, the data may not be applicable to all medical institutions.

Dr. Krumholz reports financial links with Amgen, Alere, UnitedHealthcare, and Centegen. Among the other authors, John Canto, M.D., reported financial links to Pfizer, Schering-Plough, Sanofi-Aventis, Bristol-Myers Squibb, GlaxoSmithKline, and NRMI/Genentech. Hal Barron, M.D., is the chief medical officer of Genentech. Martha Blaney, PharmD, and Susan Morris, Ph.D., are employees of the company. Lori Parsons and Dave Miller are employees of Ovation Research Group, a company that receives research funding from Genentech.