Houston ? Surgeons successfully implanted a pacemaker in former Polish President Lech Walesa on Friday and hope it will keep the Nobel laureate from needing a heart transplant.

The device was implanted during a two-hour hour procedure at Methodist DeBakey Heart and Vascular Center. Doctors said the 64-year-old Walesa was doing well.

“We are very happy with the results,” said Dr. Miguel Valderrabano, the lead doctor on the procedure.

Walesa came to Houston for tests this week and had a stent implanted into a clogged coronary artery Wednesday. Among his symptoms were chest pain, fatigue and shortness of breath. He previously had a heart attack and suffers from sleep apnea and diabetes.

Valderrabano characterized the procedure as routine, saying the hospital does about five per week on average.