Operators who performed PCI the night before are no more likely to put the next day’s patients at risk of in-hospital bleeding or mortality than those who got more rest, according to a study published in the January 2015 issue of JACC: Cardiovascular Interventions. However, the odds of bleeding may be increased if the sleep deprivation becomes chronic.

Herbert D. Aronow, MD, MPH, of Michigan Heart (Ann Arbor, MI), and colleagues analyzed National Cardiovascular Data Registry (NCDR) CathPCI Registry data on 1,509,096 PCIs performed in the daytime (between 7 AM and midnight) by 5,014 operators from July 2009 through June 2012. Median patient age was 65 years, more than two-thirds of patients were men, and almost 90% were Caucasian.

Operators were considered acutely sleep deprived if they had performed another “middle-of-the-night” case between midnight and 6:59 AM before the daytime PCI and chronically sleep deprived if they had performed multiple middle-of-the-night PCIs during the previous 7 days.

Only 2.4% of all daytime PCIs (n = 36,049) were completed by sleep-deprived operators. Although patient characteristics were similar between groups, more daytime PCIs performed by sleep-deprived operators were for STEMI (18.4% vs 14.0%) or in patients with Canadian Cardiovascular Society angina class IV angina (33.2% vs 28.6%) than those performed by operators who got sleep.

Patients who underwent PCI completed by a fatigued operator were less likely to have an elective procedure (39.4% vs 44.4%), less likely to have preprocedure TIMI flow grade 3 (52.1% vs 56.4%), more often treated with unfractionated heparin (54.3% vs 51.2%), and less often treated with bivalirudin (53.9% vs 57.3%). Sleep-deprived operators were less likely to perform PCI for a chronic total occlusion and to use bleeding avoidance therapies, such as transradial access, bivalirudin, and/or vascular closure devices (77% vs 78.6%).

Mortality, Bleeding Risks Similar Irrespective of Night Before

In-lab outcomes, including coronary artery dissection and perforation and successful lesion treatment, occurred at similar rates within each group. PCI by a sleep-deprived operator was associated with higher unadjusted rates of in-hospital mortality (1.6% vs 1.3%) and bleeding (6.1% vs 5.4%; P < .001 for both), but the differences were no longer significant after risk adjustment (table 1).

The composite of many potential PCI complications—dissection, perforation, MI, shock, heart failure, stroke, tamponade, new dialysis requirement, blood transfusion, bleeding event within 72 hours, other vascular complication, emergency CABG, or death—was more common among patients whose PCIs were done by a sleep-deprived operator, but the association was not significant after adjustment.

In sensitivity analyses accounting for a narrower middle-of-the-night PCI time window, next-day procedures only during “normal business hours,” stratification of cases according to the number of middle-of-the-night PCIs completed earlier on the same day, and procedures by the same operator when sleep-deprived vs nonsleep-deprived, there were no differences in adjusted mortality or bleeding.

Procedures performed by operators with chronic sleep deprivation (1.3% of daytime procedures) were not associated with higher mortality (adjusted OR 0.81; 95% CI 0.62-1.05) but were tied to a higher likelihood of bleeding (adjusted OR 1.19; 95% CI 1.05-1.34).

Multiple Factors May Explain Lack of Harm

Though other studies have found that “operator sleep deprivation resulting from extended work hours results in impaired operator cognitive and psychomotor function and the occurrence of serious medical errors,” the study authors write that patient outcomes were only impacted “in rare circumstances” by their interventional cardiologist being sleep deprived, confirming similar data from a previous single-center study.

In an accompanying editorial, Kirk N. Garratt, MSc, MD, of Lenox Hill Hospital (New York, NY), highlighting the “notoriously limited” nature of registry studies, points out that the NCDR data do not capture whether—or how much—rest physicians may have had between procedures.

Regarding that issue, study coauthor James C. Blankenship, MD, of Geisinger Medical Center (Danville, PA), told TCTMD in a telephone interview that after middle-of-the-night PCI “almost never in my practice and, I suspect in most practices, [is it the case] that you get no sleep [before PCI the next day].” This is often because interventional procedures are usually short, allowing for sleep to be structured around them, he explained.

Dr. Blankenship said the results reflect the increasing importance of teamwork in interventional cardiology. “We work in highly functional teams,” he noted. “If I miss something [a member of my team] will catch it.”

Highlighting the finding that PCIs done by sleep-deprived operators were less often elective, the authors explain, “It is possible that sleep-deprived operators are less likely to schedule or more likely to defer elective procedures on postcall days.” In his editorial, Dr. Garratt agrees, writing that sleep-deprived physicians may have self-regulated their caseloads.

Results Could Inform Discussion on Work Hours

Yet Dr. Garratt also warns that just because operators performed well as a whole “doesn’t mean that all physicians performed well.”

Regarding the increased risk of bleeding seen with chronic sleep deprivation, he says, “I struggle to understand why bleeding avoidance strategies (use of bivalirudin, radial access, and vascular closure devices), which were used only slightly less often by sleep-deprived physicians, should be so much less effective in this setting.”

Dr. Blankenship, however, described the results as “reassuring.” Other secondary outcomes, which may be more likely to reflect fatigue, “did not show any trends in a dangerous direction,” he said.

“Although seemingly contrary to intuition and the tenets of sleep science…,” Dr. Garratt concludes, “this work will stand as an important reference piece on the effects of late-night work and next-day interventional performance and should inform discussions about cath lab work-hours policies.”

Sources:
1. Aronow HD, Gurm HS, Blankenship JC. Middle-of-the-night percutaneous coronary intervention and its association with percutaneous coronary intervention outcomes performed the following day: an analysis from the National Cardiovascular Data Registry. J Am Coll Cardiol Intv. 2015;8:49-56.

2. Garratt KN. Should interventionalist work hours be restricted after a night on call [editorial]? J Am Coll Cardiol Intv. 2015;8:57-59.

Disclosures:

• This study was supported by the American College of Cardiology Foundation NCDR.
• Drs. Aronow and Blankenship report no relevant conflicts of interest.
• Dr. Garratt reports serving as a consultant for Abbott Vascular, Boston Scientific, and The Medicines Company; receiving research support from Boston Scientific, CeloNova, and Mayo Clinic Foundation; and having equity in Infarct Reduction Technologies and Guided Delivery Systems.

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