Menu

Why Afternoon Open Heart Surgery Is Better for Patient Outcomes

Research in human patients and mice reveals the role of the circadian clock in the risk of heart damage at different times of day.

Oct 27, 2017
Catherine Offord

WIKIMEDIA, ION CHIBZIIOpen heart surgery is linked to better patient outcomes when carried out in the afternoon, rather than in the morning, according to a study published yesterday (October 26) in The Lancet. The reasons have to do with circadian rhythms, and the risk of heart damage following operation, researchers report.

“Our study found that post-surgery heart damage is more common among people who have heart surgery in the morning, compared to the afternoon,” says coauthor David Montaigne of the University of Lille, France, in a statement. “Our findings suggest this is because part of the biological mechanism behind the damage is affected by a person’s circadian clock and the underlying genes that control it.”

In an observational study of nearly 600 people receiving heart valve replacement surgery from January 2009 to December 2015, the team identified a 50 percent lower risk of heart failure or another cardiac event in people operated on in the afternoon, instead of in the morning. A one-year, randomized controlled trial of 88 patients that concluded last February also established a causal link in the same direction between time of day and surgery outcomes.

To understand the mechanisms responsible for the findings, the researchers analyzed 30 tissue samples from a subgroup of patients in the most recent trial, and found that afternoon surgery samples were quicker to regain the ability to contract when put in conditions mimicking blood filling back into the heart. These samples also revealed differential expression of 287 circadian clock-related genes between morning and afternoon samples.

In a subsequent mouse study, the team showed that using experimental drugs to reduce the activity of one of the genes expressed at higher levels in the morning could reduce the risk of heart damage following surgery. Study coauthor Bart Staels of the University of Lille tells STAT that “one could imagine, quite rapidly, a pharmacological approach that could basically wipe out the effects between morning and afternoon.”

From a biological point of view, the results are “not hugely surprising,” John O’Neill of the UK Medical Research Council’s Laboratory of Molecular Biology tells the BBC. “Just like every other cell in the body, heart cells have circadian rhythms that orchestrate their activity. Our cardiovascular system has the greatest output around mid/late-afternoon, which explains why professional athletes usually record their best performances around this time.”

Although hospitals can hardly eliminate morning surgery altogether, the authors suggest that patients with complicating conditions such as obesity and type 2 diabetes be prioritized for afternoon operations. “We don’t want to frighten people from having surgery—it’s life saving,” Staels tells the BBC. But “if we can identify patients at highest risk, they will definitely benefit from being pushed into the afternoon and that would be reasonable.”

July 2019

On Target

Researchers strive to make individualized medicine a reality

Marketplace

Sponsored Product Updates

Overcoming the Efficiency Challenge in Clinical NGS
Overcoming the Efficiency Challenge in Clinical NGS
Download this white paper to see how an ECS lab serving a network of more than 10,000 healthcare providers integrated QIAGEN Clinical Insight (QCI) Interpret to significantly reduce manual variant curation efforts and increase workflow efficiency by 80%!
Veravas Launches Product Portfolio to Mitigate Biotin Interference and Improve Diagnostic Assay Accuracy
Veravas Launches Product Portfolio to Mitigate Biotin Interference and Improve Diagnostic Assay Accuracy
Veravas, Inc., an emerging diagnostic company, launched a portfolio of products that can improve the accuracy of current diagnostic test results by helping laboratory professionals detect and manage biotin interference in patient samples with VeraTest Biotin and VeraPrep Biotin.
New Data on Circulating Tumor DNA as a Biomarker for Detecting Cancer Progression Presented at 2019 ASCO Annual Meeting
New Data on Circulating Tumor DNA as a Biomarker for Detecting Cancer Progression Presented at 2019 ASCO Annual Meeting
Scientists presented more than 30 abstracts featuring Bio-Rad’s Droplet Digital PCR (ddPCR) technology at the American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, May 31–June 4.
BellBrook Labs Receives NIH Grant for the Discovery of cGAS Inhibitors to Treat Autoimmune Diseases
BellBrook Labs Receives NIH Grant for the Discovery of cGAS Inhibitors to Treat Autoimmune Diseases
The National Institute Of Allergy And Infectious Disease recently awarded BellBrook Labs a $300,000 Small Business Innovative Research (SBIR) grant to develop novel inhibitors for the target cyclic GAMP Synthase (cGAS). The grant will be used to accelerate the discovery of new treatments for autoimmune diseases by targeting the cGAS-STING pathway.