Adverse events due to heart attacks drop, but mortality rates increase after hours

Although new research finds patients who suffer heart attacks after hospital hours have higher mortality rates and longer wait times for procedures, another study reveals a drop in adverse events among Medicare patients who experience heart attacks and congestive heart failure.

In the first study published in the British Medical Journal, researchers analyzed almost 1.9 million patients from 48 different studies. Of these studies, 36 submitted mortality outcomes and 30 reported balloon times, according to the study abstract. Off-hour presentation for patients with acute myocardial infarction was associated with higher short-term mortality, about 5 percent. Researchers said this contributes to about 6,000 U.S. deaths every year.

Furthermore, patients with ST elevation myocardial infarction were less likely to receive percutaneous coronary intervention (PCI) within 90 minutes, and had a longer door-to-balloon time by an average of more than 14 minutes, according to the data.

About 400,000 people die from coronary heart disease and a million suffer from heart attacks in the U.S. every year, according to an article by Headlines & Global News, with cardiovascular events topping the list of leading causes of death worldwide.

Although the researchers didn't rule out other factors associated with patient characteristics as underlying causes, the link between mortality and hospital off-hours is strong. "Increased mortality during off-hours is associated with factors that arise after presentation at hospital," the authors said in the study.

However, researchers in the second study published in the New England Journal of Medicine noted that from 2005 through 2011, adverse-event rates dropped among Medicare patients hospitalized for acute myocardial infarction or congestive heart failure. The rate of heart attack patients experiencing one or more adverse events--including drug reactions, hospital-acquired pressure ulcers, falls and hospital-acquired infections--declined from 26 percent to 19.4 percent, according to Furthermore, the article noted that the rate for heart failure patients experiencing adverse events fell from 17.5 percent to 14.2 percent.

Much has been made of the "weekend effect," where patients admitted on Fridays stay longer and suffer more complications than those admitted during the week. The issue stems from a lack of clinical services on the weekends, when many diagnostic and interventional services shut down except to handle life-threatening problems. 

Even in cases when hospitals performed primary PCI on heart attack patients faster, in-hospital and 30-day mortality for these patients did not improve, FierceHealthcare previously reported.

To learn more:
- here's the BMJ study
- check out the HNGN article
- read the NEJM study