CardioExchange Archive

Two studies published this week offer fresh evidence that the time and place of a myocardial infarction (MI) make a big difference.

1. MI patients in the United Kingdom are more likely to die than MI patients in Sweden, according to a study published in the Lancet. Researchers in Sweden and the U.K. analyzed data from almost 120,000 Swedish patients and 400,000 U.K. patients who had MIs between 2004 and 2010. The 30-day rate of death was much higher among the patients in the U.K. than among those in Sweden: 10.5% vs. 7.6%. The researchers then took into account differences between the patient groups in each country by adjusting for 17 variables known to impact on mortality and found that patients in the U.K. still had an increased risk of death (standardized mortality ratio: 1.37, CI 1.30-1.45). This increased risk, they calculated, may have resulted in 11,263 excess deaths over the seven years of the study.

Among many differences between Sweden and the U.K., the researchers focused on two differences in treatment that might help account for the difference. Primary PCI was used in 59% of patients in Sweden but only 22% in the U.K. and beta-blockers were used in 89% of patients in Sweden versus 78% in the U.K.

“Our findings are a cause for concern,” said one of the authors, Harry Hemingway, of University College London in the U.K., in a Lancet press release. “The uptake and use of new technologies and effective treatments recommended in guidelines has been far quicker in Sweden. This has contributed to large differences in the management and outcomes of patients.”

2. MI patients are more likely to die if they reach the hospital at night or on the weekends, according to a study published in the BMJ. Mayo Clinic researchers analyzed data from 1.9 million MI patients and found that short-term mortality was 6% higher when patients arrived at the hospital during off hours. Patients with STEMI were 60% less likely to undergo PCI within 90 minutes if they arrived during off hours.

The authors write that these differences are likely linked to the changing availability at different times of cardiologists and cardiac catheterization laboratory support staff, since many hospitals do not run a 24-hour service and may need to activate the catheterization lab during off hours. In an accompanying editorial, Lauren Lapointe-Shaw and Chaim Bell write that “managers seeking to boost their hospital’s performance for patients with acute myocardial infarction should focus on improving their off-hour care, with the goal of providing consistently high quality care 24 hours a day and seven days a week.”