HOUSTON -- A sheriff's deputy awaiting a heart transplant died Christmas Eve after surgery to remove blood clots in his leg, just three weeks after he was married in a hospital ceremony.

Merle Nicholson, 26, who overcame leukemia as a teen-ager, died at about 10 a.m. Thursday, said Sara Peterson, a spokeswoman for St. Luke's Episcopal Hospital in Houston.

His wife, Sonya, 25, a detention officer with the Dallas County Sheriff's Department, said nothing had mattered to her more than her husband.

"He was the most important thing in my life," she said. "We all just need to take a short breath and realize that the things we take for granted and the people we take for granted aren't always going to be there with us.

"And when God is ready to take them away, we need to let them go."

Nicholson, who had been awaiting a donor heart at the hospital's Texas Heart Institute since Nov. 24, was at the top of a national priority list of patients seeking donor hearts, but Peterson said the deputy's 6-foot-4, 200-pound frame made it hard to locate a donor heart for him.

"Donors are very difficult to find," she said. "We have to match blood type as well as weight. And one simply did not become available for him."

Doctors Wednesday discovered several blood clots in one of Nicholson's legs and placed him on life support systems, then operated to remove the clots Thursday, but his condition continued to worsen, Peterson said.