Former Polish President Lech Walesa was discharged from a Houston hospital Tuesday, four days after doctors successfully fitted him with a pacemaker.

The device, expected to help Walesa, 64, avoid a heart transplant, was implanted during a two-hour procedure at Methodist DeBakey Heart and Vascular Center.

“My health is very much improved. It has been a long time since I felt this good. I have received medical care all over the world, and I never felt quite so good as I do today. This is a very good outcome and I am overjoyed that I do not need a heart transplant at this time,” Walesa said in a statement, according to Reuters.

Walesa came to Houston from Mexico last week for treatment after suffering chest pain, shortness of breath and fatigue. After the procedure, he planned to travel back to Mexico to participate in a youth conference.

“I hope to work harder than ever to help people around the word. Dictators and oppressors should continue to fear me because I will be here for a long time,” he further added.

Walesa was also tested and treated for diabetes, high cholesterol and sleep apnea, or irregular breathing while sleeping. Doctors also prescribed him an exercise program.

Walesa, awarded the Nobel Peace Prize in 1983 for his role in fighting communism in his native Poland, served a five-year term as the country’s president beginning in 1990. He was Poland’s first democratically elected president.