(AP) - Former Vice President Dick Cheney had a heart transplant Saturday and is recovering at a Virginia hospital, his office said.

An aide to Cheney disclosed that the 71-year-old, who has had a long history of cardiovascular trouble including numerous heart attacks, had been waiting for a transplant for more than 20 months.

"Although the former vice president and his family do not know the identity of the donor, they will be forever grateful for this lifesaving gift," aide Kara Ahern said in a written statement that was authenticated by several of the Republican politician's close associates.

Cheney was recovering Saturday night at the Intensive Care Unit of Inova Fairfax Hospital in Falls Church, Va., after surgery earlier in the day.

The former vice president suffered a heart attack in 2010, his fifth since the age of 37. That year, he had surgery to have a small pump installed to help his heart keep working. It was one of the few steps left, short of a transplant, to stay alive in the face of what he acknowledged was "increasing congestive heart failure."

The pump, called a left ventricular assist device, is mainly used for short periods to buy time for potential transplant candidates awaiting a donor organ. The fact that doctors resorted to it illustrated the perilous condition he was in.

In July 2007, he had had a minor surgical procedure to replace a device that monitored his heartbeat. Nearly 20 years earlier, in 1988, Cheney had had quadruple bypass surgery, and had two artery-clearing angioplasties and the operation to implant the device.

In 2005, Cheney had six hours of surgery on his legs to repair a kind of aneurysm, and in March 2007, doctors discovered deep venous thrombosis in his left lower leg. An ultrasound a month later showed the clot was getting smaller.

In January 2011, Cheney said he was getting by on a battery-powered heart pump, which made it "awkward to walk around." He also said he hasn't made a decision yet on a transplant, but that "the technology is getting better and better."

Cheney said then that he'd "have to make a decision at some point whether I want to go for a transplant."

Cheney served as former President George W. Bush's vice president for eight years, from 2001 until 2009. Cheney was a lightning rod for criticism during Bush's presidency, accused by opponents of often advocating a belligerent U.S. stance in world affairs during wars in Iraq and Afghanistan.