New York (CNN Business) Apple is partnering with Johnson & Johnson to reduce the risk of strokes in senior citizens.

J&J JNJ Apple AAPL andannounced Tuesday that US citizens over the age of 65 (with a traditional Medicare plan) will be eligible to participate in clinical research through the Heartline Study app on iPhones. They'll also have access to heart health features on Apple Watch models. The patients must also agree to provide access to their Medicare claims data.

"Heartline could go down as a landmark clinical trial. We are bringing amazing digital wearable tech and engagement apps for healthcare to patients and doctors," said Dr. Paul Burton, vice president of medical affairs for J&J's Janssen Pharmaceutical Companies unit, in an interview with CNN Business.

The study is designed to detect atrial fibrillation or AFib, an irregular heart rhythm that is a leading cause of stroke.

"AFib can potentially lead to more strokes for people over the age of 65. Cases are more common," Burton said. "And people fear having a stroke as much as dying."

Read More