Our Summary

This study looks at the link between changes in our DNA, how our energy-making cells (mitochondria) function, and mild cognitive decline (MCI) - a condition where people have slight but noticeable and measurable declines in cognitive abilities, including memory and thinking skills. Researchers are interested in this as some people who undergo coronary artery bypass graft surgery (a procedure where a blood vessel is taken from one part of the body to replace or bypass a blocked artery in the heart) experience cognitive decline afterwards.

The study involved 70 patients who had this surgery and 25 people of a similar age who did not. They tested their cognitive function using a standard test (the Montreal Cognitive Assessment) before and after the surgery. They also took blood samples before and one day after the surgery to examine the functioning of the mitochondria and to look at the expression of certain genes related to DNA methylation - a process that controls gene activity.

They found that 44% of patients showed signs of MCI after the surgery. These patients showed a significant decrease in a certain mitochondrial activity and an increase in a marker for oxidative stress compared to the control blood samples. The post-surgery samples also showed changes in the expression of certain genes relating to DNA methylation.

The results suggest that both changes in DNA methylation and mitochondrial function are associated with cognitive decline after heart bypass surgery. This could potentially be used to identify those who are more likely to experience cognitive decline after surgery and may lead to interventions to prevent this happening.

FAQs

  1. What is the link between DNA changes, mitochondrial function, and mild cognitive decline?
  2. How does coronary artery bypass graft surgery potentially impact cognitive function?
  3. Can the changes in DNA methylation and mitochondrial function be used to predict those who will experience cognitive decline after heart bypass surgery?

Doctor’s Tip

A helpful tip a doctor might tell a patient about CABG is to stay physically active and follow a healthy diet post-surgery to help improve overall cardiovascular health and potentially reduce the risk of cognitive decline. Additionally, keeping up with regular follow-up appointments and discussing any cognitive changes with your healthcare provider can help address any concerns early on.

Suitable For

Patients who are typically recommended coronary artery bypass graft surgery (CABG) are those with severe coronary artery disease that cannot be managed effectively with medications or other less invasive procedures such as angioplasty. These patients may have blockages in multiple coronary arteries, severe chest pain (angina), or a history of heart attacks.

In this study, the patients who underwent CABG and experienced cognitive decline afterwards were older adults, which is a common demographic for this type of surgery. It is important to note that not all patients who undergo CABG will experience cognitive decline, but it is a potential risk factor that should be considered, especially in older patients.

Timeline

  • Before CABG: Patients may experience symptoms of coronary artery disease such as chest pain, shortness of breath, and fatigue. They may undergo various tests such as an angiogram to determine the extent of blockage in their arteries. Once it is determined that they need CABG surgery, they will be evaluated by a cardiologist and a cardiothoracic surgeon. They may also undergo preoperative testing such as blood tests, chest x-rays, and an electrocardiogram.

  • Day of CABG: Patients will be admitted to the hospital and prepared for surgery. They will undergo general anesthesia before the surgery. During the procedure, the surgeon will take a blood vessel from another part of the body (often the leg or chest) and use it to bypass the blocked artery in the heart. The surgery can take several hours to complete.

  • After CABG: Patients will be monitored closely in the intensive care unit (ICU) immediately after surgery. They will be given pain medication and may have a breathing tube in place to help with breathing. As they recover, they will be moved to a regular hospital room where they will continue to be monitored for any complications. Physical therapy may be started to help with recovery and prevent blood clots.

  • Post-surgery follow-up: Patients will have regular follow-up appointments with their cardiologist to monitor their progress and make sure their heart is healing properly. They may be prescribed medications such as blood thinners and cholesterol-lowering drugs to prevent future blockages. They will also be advised to make lifestyle changes such as quitting smoking, eating a healthy diet, and exercising regularly to improve their overall heart health.

What to Ask Your Doctor

  1. What are the potential risks and benefits of undergoing coronary artery bypass graft surgery (CABG) in relation to cognitive decline?
  2. How common is cognitive decline after CABG surgery, and what factors may contribute to it?
  3. Are there any specific pre-operative tests or assessments that can help predict the likelihood of cognitive decline after surgery?
  4. What measures can be taken during and after surgery to reduce the risk of cognitive decline?
  5. Are there any lifestyle changes or interventions that can help improve cognitive function after CABG surgery?
  6. How long does cognitive decline typically last after surgery, and is it reversible?
  7. Are there any medications or therapies that can help manage cognitive decline post-surgery?
  8. How often should cognitive function be monitored post-surgery, and what signs should I be aware of that may indicate cognitive decline?
  9. Are there any research studies or clinical trials investigating potential treatments or preventative measures for cognitive decline after CABG surgery that I may be eligible to participate in?
  10. What support resources are available for patients experiencing cognitive decline after CABG surgery?

Reference

Authors: Boovarahan SR, Kale SB, Prem PN, Ravindran S, Arthanarisami A, Rengaraju J, Ali N, Ramalingam S, Mohany M, AlAsmari AF, Al-Rejaie SS, Waseem M, Kurian GA. Journal: J Clin Med. 2023 Jun 20;12(12):4146. doi: 10.3390/jcm12124146. PMID: 37373839