Once in hospital, MI patients should be treated without delay to cut their risk of death, ideally within even less than the 90 minutes currently recommended by clinical guidelines, according to a study published May 18 in the British Medical Journal.
U.S. researchers set out to investigate the association between door-to-balloon (D2B) time and deaths in hospitals among patients undergoing balloon angioplasty after a heart attack.
Saif S. Rathore, in the MD/PhD program at Yale University School of Medicine in New Haven, Conn., and colleagues analyzed data for 43,801 patients from the American College of Cardiology's (ACC) National Cardiovascular Data Registry (NCDR). All patients underwent balloon angioplasty within 12 hours of a heart attack at a U.S. acute-care hospital between 2005 and 2006.
The average D2B time was 83 minutes, with more than half of patients (58 percent) treated within 90 minutes of admission. Overall, in-hospital mortality was 4.6 percent, according to the researchers. A greater proportion of patients who had longer D2B times were women, non-white and, on average, older than patients with shorter D2B times. Those with longer times also had more comorbidities than patients with shorter D2B times.
After adjusting for factors that may have affected the results, longer D2B times were associated with a higher risk of in-hospital mortality, Rathore and colleagues reported. For example, 3 percent of patients with D2B times of 30 minutes died in hospital, while 4.3 percent of patients with D2B times of 90 minutes died. The highest mortality rate (10.3 percent) was for patients with D2B times of 270 minutes.
These results indicate that any delay in D2B time for heart attack patients undergoing balloon angioplasty is associated with higher mortality, even among patients treated within 90 minutes of admission, the authors wrote.
"Rather than accepting the 90-minute door-to-balloon time benchmark, our data support calls for an 'as soon as possible' standard for patients undergoing primary percutaneous coronary intervention. Such an approach, using necessary safeguards against inappropriate treatment, offers the potential for notable mortality reduction," they concluded.
Rathore and colleagues added that the "time to treatment should be as short as possible, even in centers currently providing primary PCI within 90 minutes."