Impact of Operative Timing on Postoperative Survival Following Major Cardiac Procedures

Article Impact Level: HIGH
Data Quality: STRONG
Summary of  Anaesthesia  https://doi.org/10.1111/anae.70125 
Dr. Gareth Kitchen  et al.

Points

Researchers analyzed data from over twenty-four thousand patients across the United Kingdom to determine if the specific time of day heart surgery begins significantly impacts long-term survival outcomes.
The study found that surgeries starting between ten and noon were associated with an eighteen percent higher risk of cardiovascular death when compared directly to those performed in the early morning.
Statistical adjustments for age and surgical complexity confirmed that these mortality differences persist even when accounting for the inherent difficulty or the specific urgency of the cardiac procedures being performed.
While complication rates and readmission frequencies were not affected by scheduling the researchers believe that integrating body clock biology into surgical planning could one day improve overall patient safety metrics.
Optimizing operative timings represents a potentially inexpensive method for clinicians to achieve better outcomes by aligning complex heart procedures with the most favorable periods of the human circadian cycle.

Summary

This cohort study, published in Anaesthesia, analyzed four linked national datasets comprising over 24,000 patients across England, Wales, and Northern Ireland to determine if the time of day of surgical initiation correlates with postoperative mortality. Researchers evaluated four distinct start-time intervals: early morning (07:00–09:59), late morning (10:00–11:59), early afternoon (12:00–13:59), and late afternoon (14:00–19:59). The analysis adjusted for critical mortality predictors, including age, sex, diabetes, and surgery urgency, to isolate the independent effect of scheduling on patient survival.

The findings demonstrated that heart surgery initiated in the late morning was associated with an 18% higher risk of cardiovascular mortality compared to early-morning procedures. Although the 07:00–09:59 window remains the most common start time, accounting for 47% of all surgeries, the shift to a late-morning schedule appears to carry a statistically significant hazard for heart-related death. Notably, complication rates, hospital stay duration, and readmission frequencies for myocardial infarction or acute heart failure remained unaffected by the time of day, suggesting a specific vulnerability related to cardiovascular survival rather than general surgical morbidity.

Given that approximately 25,000 heart operations are performed annually in the UK with a baseline mortality rate of 2.7%, these results suggest that chronotherapeutic scheduling could offer a low-cost intervention to improve outcomes. The researchers propose that integrating circadian biology and individual chronotypes into surgical planning could facilitate a more personalized, precision medicine approach. Further investigation is warranted to determine if organizational factors or individual biological clocks drive this variation, potentially allowing clinicians to optimize operative timings for higher-risk cardiac populations.

Link to the article: https://associationofanaesthetists-publications.onlinelibrary.wiley.com/doi/10.1111/anae.70125

References

Kitchen, G., Thomas, K., Felton, T., Durrington, H., Blaikley, J., Grant, S. W., Harrison, D., McGuigan, P., Rowan, K., Wilson, A., McAuley, D., & Dark, P. (2026). Time of day of cardiac surgery and postoperative outcomes in the UK: A secondary analysis of linked national datasets. Anaesthesia, anae.70125. https://doi.org/10.1111/anae.70125