Angioplasty During Off-hours Associated With Poor Outcome

NEW YORK (Reuters Health) – As a treatment for acute MI, coronary angioplasty is less likely to be successful and is tied to a higher 30-day mortality rate when performed during off-hours rather than between 8 am and 6 pm, according to results of a new study.

The findings, which are published in the June 18th issue of the Journal of the American College of Cardiology, suggest that circadian patterns have a strong impact on angioplasty outcomes. However, the results also raise concern that care could be inferior during off-hours.

“It’s quite clear that it’s better to come in during the day than during the night,” senior author Dr. Felix Zijlstra, from Hospital De Weezenlanden in Zwolle, the Netherlands, said in a statement. “Mortality of nighttime patients is twice the mortality of daytime patients.”

In the new study, Dr. Zijlstra’s team assessed the outcomes of 1702 patients with acute ST-segment elevation MI who underwent primary angioplasty.

The percentage of patients who experienced symptom onset, hospital admission, and first balloon inflation during routine duty hours (8 am to 6 pm) was 53%, 53%, and 52%, respectively.

The authors found no differences between routine- and off-hour patients in baseline clinical characteristics or in the time from symptom onset to treatment. Still, off-hour angioplasty procedures had a failure rate of 6.9%, significantly higher than the 3.8% rate associated with routine-hour angioplasty (p < 0.01). Unfortunately, the adverse effects of off-hour angioplasty were not limited to the immediate periprocedural period, the investigators note. The 30-day mortality rate for patients treated during off-hours was 4.2%, while the rate for patients treated during routine hours was only 1.9% (p < 0.01). Further studies are needed to clarify the reason for the apparent link between time of angioplasty and clinical outcomes, Dr. Zijlstra noted. He believes that it is probably due to inherent differences between patients who present during the day versus the night, rather than due to differences in quality of care. However, in a related editorial, Dr. Frederick A. Spencer and Dr. Richard C. Becker, from the University of Massachusetts Medical School in Worcester, comment that quality of care may play an important role. There is strong evidence that sleep deprivation adversely affects cognitive performance and motor function and, as it relates to on-call physicians, this could translate into inferior quality of care at night, they add. J Am Coll Cardiol 2003;41:2138-2145.