He suffered a near-fatal brain hemorrhage in April, just weeks after undergoing an emergency appendectomy, and then suffered a minor stroke. During his hospitalization, doctors discovered a hole in his heart that he'd had since birth.
Michaels confirmed the latest health issue on his website in May and indicated he was taking a regimen of blood thinners to treat it.
And now he is scheduled to go under the knife to repair the defect after his Roses & Thorns tour wraps in December.
The spokesperson adds, "The next thing he has is his book tour (beginning) March 15, on his birthday. After the holidays, he'll do this and then have time to heal before the whole book publicity campaign."