Those who undergo heart bypass surgery could be at higher risk of developing Alzheimer’s disease, a new study indicates.

Researchers looked at more than 5,200 people who had undergone coronary artery bypass surgery and almost 4,000 people who had coronary angioplasty. During a five-year monitoring period, researchers found that 78 of those who had bypass surgery developed Alzheimer’s. That compares to 41 who had undergone angioplasty.

Coronary bypass patients had a 70% increased risk of developing Alzheimer’s, researchers found. Details of this research are published in the Journal of Alzheimer’s Disease.