Heart disease is part of the genetic history of the male Coburg Gotha line. Baudouin's father died from it, his brother King Albert has been operated for heart problems and his younger brother Prince Alexandre died from sudden heart failure in his 50's.
Baudouin first began to experience heart problems in his early 40's. The poor man also suffered from sciatica for most of his adult life. ( Paul Belien " A Throne for Brussels")
He spent part of the State Visit to Chile and Brazil in 1965 on crutches.
Baudouin was operated on for a leaking heart valve in his late 50's. According to a report I read after his death Ftench President Mitterand was informed by French intelligence sources that the surgery was botched and unsuccessful. I also read a rumor that Baudouin's step-mother the Princess de Rethy had tried to persuade him to have the operation at the world renowned Cleveland Clinic.
Baudouin was no longer close to Princess Liliane and refused(sadly imho)
Anyway he was never completely well afterwards. In the few years he had left he became fatigued easily and suffered from depression.
At his final National Day in July 1993, ten days before his death, he can be seen looking ashen and leaning heavily on a sword or cane.
Andalusia Spain is where he and Fabiola kept s vacation home since 1965. They went there alone immediately after National Day 1993. They liked to have minimal or no staff with them on their holidays.
It was a blistering hot Saturday evening on July 31st 1993. Baudouin was reading on the terrace of the villa. Fabiola wss in the kitchen preparing dinner. When she called to him he did not come.
I don't remember if it was Fabiola or an aide de camp who found Baudouin slumped back in his chair. Dr. Carlos Aguada told Spanish Hola that the king had died with his eyes half-open..which indicated that death had come very quickly and suddenly.
He was only 62 years old...about 6 weeks shy of his 63rd birthday.
His sudden death was a great and terrible shock to his family and to the Belgians and all of Europe. It made the front pages of the New York Times, i remember it well.
The only controversy and criticism i can remember came from.people who questioned the wisdom of a king with a serious heart problem going to vacation in extreme heat without being accompanied by his personal physician.
I have also heard that very high heat and humidity is particularly bad for people with heart problems.
Hope this helps.