Study: Hospitals That Send the Most Heart Patients to the ICU Get the Worst Results

High ICU use linked to higher post-discharge mortality

Patients who experience heart attacks or flare-ups of congestive heart failure can be cared for in a variety of hospital locations. But a new study suggests that they may fare worse in hospitals that rely heavily on intensive care units (ICUs) to care for patients like them.

The findings add to growing evidence that the use of ICU beds in the United States varies widely. But for the first time in heart care, the study shows that hospitals that send the highest percentage of their patients to the ICU perform worst on measures of health care quality.

This suggests that more standardization in deciding which patients need an ICU, and more focus on quality of care in hospitals with the highest ICU use, could benefit patients nationwide, according to the authors of a new paper published online in Chest.

Lead investigator Thomas Valley, MD, MSc, and his colleagues at the University of Michigan Medical School reached their findings by looking at Medicare records from more than 570,000 hospital stays that took place in 2010.

Of the more than 150,000 hospitalizations at nearly 1,700 hospitals for acute myocardial infarction (AMI), 46% included care in an ICU. A lower, but still sizable, 16% of the more than 400,000 hospitalizations for heart failure also included an ICU stay at one of 2,199 hospitals.

Hospitals in the lowest quintile had ICU admission rates of less than 29% for AMI and less than 8% for heart failure (HF). Hospitals in the top quintile had admission rates greater than 61% for AMI and greater than 24% for HF. Hospitals in the top quintile also had greater 30-day mortality (14.8% vs. 14.0%, P = 0.002 for AMI; 11.4% vs. 10.6%, P < 0.001 for HF) when compared with hospitals in the lowest quintile. The two groups had no differences in 30-day readmission rates.

The new results show that hospitals with the highest percentage of patients admitted to the ICU tended to be those with the smallest numbers of heart attack and HF patients overall, perhaps suggesting a lack of familiarity with these conditions, the authors noted. They were also more likely to be for-profit hospitals, and patients treated in them were more likely to be from low-income ZIP codes.

But the biggest difference was in the risk of dying within 30 days of discharge. Heart attack patients treated in hospitals with high ICU use were 6% more likely to die than were patients admitted to hospitals with low ICU use, and the difference was about 8% for HF patients. There were no differences in the odds of being re-hospitalized, or in total spending on care.

“These studies suggest that hospitals using the ICU frequently could be targets for improvement. If we find out why hospitals are using ICU beds more often for these patients, we could intervene to improve care overall,” Valley said.

Sources: University of Michigan Health System; August 3, 2016; and Chest; June 2016.