NEW YORK - Former President Bill Clinton sailed through quadruple bypass surgery yesterday in what surgeons called a routine but necessary operation to prevent a major heart attack.
Doctors at New York-Presbyterian Hospital said Clinton could be released from the hospital in four or five days if initial recovery goes well, and that the signs looked good so far. At 4 p.m. yesterday, four hours after surgery, he was said to be under sedation but responding to commands.
"He will gradually resume a normal routine of exercise and activity at home," said Dr. Allan Schwartz, chief of cardiology, who did not rule out Clinton's making campaign appearances before the November presidential election.
"After all, this isn't the average person in recovery," Schwartz said.
Clinton had planned to campaign for Sen. John Kerry, the Democratic nominee, and has been aggressively promoting his memoir, My Life.
Without surgery, Clinton, 58, would have faced a grave risk of heart attack, doctors said. Despite serious coronary disease, his heart muscle was undamaged and pumped vigorously before and after surgery, doctors said.
"He will have a normal longevity," Schwartz said.
Sen. Hillary Rodham Clinton and their daughter, Chelsea, were at Clinton's side in the waiting room before surgery and stayed there during the four-hour operation. Afterward, they spent time with him in the recovery room, hospital officials said.
"The president's optimism and faith will carry him through the coming weeks and months," Senator Clinton said in a statement issued to a throng of reporters assembled for a briefing in the hospital lobby. "Of that we have no doubt."
The three have stayed up late in his ninth-floor room "talking, playing games and just being with each other," said Dr. Herbert Pardes, the hospital president.
Clinton has received more than 45,000 get-well wishes.
Although early reports last week indicated that Clinton felt his first symptoms of chest pain on Thursday - leading to tests that revealed four blockages and the need for surgery - doctors said he began feeling tightness in his chest and shortness of breath with activity several months ago.
But Clinton dismissed the symptoms as the result of poor conditioning. Also, he had suffered from acid reflux - heartburn - for some time and assumed that his discomfort might have come from that, doctors said. People with angina, a type of chest pain that can precede a heart attack, often mistake their symptoms for heartburn.
Doctors said Clinton's symptoms disappeared and did not return until Thursday, when he experienced chest pain while resting. He underwent initial tests that day at a hospital in Westchester County, north of the city, where doctors recognized the seriousness of his problem and transferred him to Presbyterian, home of one of the nation's leading heart centers.
There, tests revealed four blockages in his coronary arteries, which run along the surface of the heart, providing oxygen and nourishment. Doctors said the blockages, some of which restricted blood flow by 90 percent, were in three major coronary arteries and one branch.
Clinton's surgery was postponed until yesterday to allow time for blood-thinning medication, which was given initially to reduce clotting, to pass out of his system. That in turn minimized bleeding that can occur during surgery.
Clinton was wheeled into the operating room about 8 a.m., and the procedure was over by noon. He spent 73 minutes on a heart-lung machine, which circulates blood while the heart is stopped.
Dr. Craig R. Smith, chief of cardiothoracic surgery and the lead surgeon yesterday, said he decided not to operate on a beating heart because of quirks in his patient's arterial road map that would have made that too risky.
Some doctors favor beating-heart surgery out of concern that placing the blood supply on mechanical support can leave patients with memory and cognitive problems, but Smith said that any such problems disappear within a year and that evidence of lasting deficits is lacking.
Smith said he used arteries from Clinton's chest and a vein from his leg to create detours for blood to flow around the blockages. A team of 15 surgeons, anesthesiologists, nurses and technicians was on hand, a normal contingent for patients with advanced coronary disease, officials said.
"There was nothing in this case outside the realm of routine," said Smith, who performs more than 350 operations a year, many of them heart bypasses and valve repairs.
A dietitian will work with the former president to devise a diet low in salt and saturated fat that suits his palate, Schwartz said. Clinton had indulged his fondness for fast food for many years, though in the past year he was on the South Beach diet and appeared fit and trim.
During the past year Clinton had taken a cholesterol-lowering medication for slightly elevated LDL, the so-called bad cholesterol, but a doctor he was seeing for the problem took him off the drug when he lost weight and seemed to have his diet under control.
Though it might be easy to say that the doctor should have continued the medication, Schwartz refused to second-guess him.
"Was it a mistake?" Schwartz said in response to a question. "No, it was a judgment."
The Associated Press contributed to this article.