ORLANDO, FLA. — One in 12 patients with acute MI presents with a concomitant acute potentially life-threatening noncardiac condition at admission, Judith H. Lichtman, Ph.D., reported at the annual meeting of the American College of Cardiology.
None of the current risk-adjustment models for MI patients that are widely used to guide clinical care and benchmark hospital and physician performance take account of these life-threatening noncardiac conditions.
Instead, the prognostic models are restricted to variables that are directly related to the patient's cardiovascular disease. That's largely because the models were developed using data from randomized clinical trials from which patients with significant comorbidities are generally excluded.
As a consequence, the risk-adjustment models fail to account for much of the variation in short-term outcomes in MI patients, explained Dr. Lichtman of Yale University, New Haven.
This is a glaring oversight, she stressed, because those 1 in 12 MI patients who have a dueling potentially life-threatening acute noncardiac condition account for a disproportionate share of total inpatient deaths.
Indeed, in the Prospective Registry Evaluating Outcomes After Myocardial Infarction: Events and Recovery (PREMIER) study such patients had an in-hospital mortality of 20%, compared with 3% in MI patients without such comorbidities.
“We feel that in this study we've identified a very important subgroup of acute MI patients at increased risk for mortality that have really not been previously described in the literature,” Dr. Lichtman added.
The PREMIER registry involved 3,948 acute myocardial infarction patients prospectively enrolled at 19 participating U.S. medical centers during 2003–2004. Chart review showed that 8% of these patients enrolled had an acute potentially life-threatening noncardiac condition present at the time of their admission.
These were not chronic conditions such as arthritis or seizure disorders. The most common of these conditions included severe pneumonia requiring intubation, trauma, stroke, sepsis, severe GI bleeding, and hip fracture.
Patients who present with one of these conditions in addition to an acute MI typically have been found to require care from multiple specialists, including both cardiovascular and noncardiovascular.
The MI patients with acute potentially life-threatening noncardiac conditions in PREMIER presented differently from those with MI alone. They were older—a mean age of 62 years compared with 56—and more likely to be women and nonwhite.
They also were more likely to have diabetes and hypertension and less likely to present with ST-elevation MI. And they were less likely to receive early therapy with aspirin, fibrinolytic agents, and β-blockers, as recommended in national guidelines.
After adjustment for the lesser use of guideline-based initial therapies for MI in the patients with potentially life-threatening comorbid conditions, along with differences in demographics, prior history, and clinical presentation, the patients still had a 4.9-fold increased risk of in-hospital mortality.
“I think this underscores a strong need to adopt a broader perspective of the clinical factors that contribute to the initial assessment, process of care, and outcomes for acute MI patients. … These factors need to be put on the radar of these risk-adjustment models,” Dr. Lichtman concluded.
Session cochair Eric D. Peterson, M.D., of Duke University in Durham, N.C., who was a coinvestigator in the PREMIER registry, said that while most MI patients with an acute potentially life-threatening noncardiac condition are routinely admitted to coronary care units, it might make more sense for them to go directly to the intensive care unit, where the caregivers are experienced in managing a wider array of very serious medical conditions.