Patients with heart failure are more likely to die after surgery than patients without heart failure, a study led by surgeon Sherry Wren, MD, has found. The higher mortality rate held even when the researchers considered that heart failure patients are generally in poor health and are more likely to undergo complex surgeries.
"We adjusted for the level of surgery complexity," said Ben Lerman, a fourth-year medical student who was the lead author on the study. "We also split up patients by the degree of heart failure, comparing like to like. That effect, the higher mortality, remains."
In other words, if you take two 80-year-old male patients with the same health problems, except that one has heart failure and the other doesn't, and perform the same surgery on them, the one with heart failure is more likely to die.
Even patients with the least severe heart failure -- a group that Wren said has never been studied -- suffered higher mortality after surgery.
The study appears in the Journal of the American Medical Association.
Heart failure, a condition in which the heart is unable to adequately pump blood throughout the body, is relatively common: 5.7 million people in the U.S. live with heart failure. It is also progressive: About half will die within five years of diagnosis.
Surgeons are aware that heart failure is a risk factor, Wren said, but prior research hadn't quantified the risk. "I really felt that there was an underappreciation by surgeons, cardiologists and internal medicine doctors that heart failure, especially non-symptomatic or non-severe heart failure, had on postoperative death risk," she said.
Wren, Lerman and their colleagues examined data on 609,735 Veterans Affairs patients who underwent elective surgery, which is any surgery that can be scheduled in advance, even though it may be a life-saving procedure.
They found that within 90 days after surgery, 10.1 percent of heart failure patients who had symptoms from their heart condition died. For asymptomatic heart failure patients, that number was 4.9 percent, and for patients without heart failure, it was 1.2 percent.
While all heart failure patients showed higher death rates, Wren said, "the worse the heart failure, the greater the mortality."
The researchers conjectured that heart failure patients may not tolerate anesthesia as well as patients without heart failure. "Surgery is a massive physiological stress on even a healthy body," Lerman said. "Even when patients' hearts can handle everyday life, it seems they sometimes can't handle the stress of surgery."
Lerman and Wren said that they hope their findings are included in the American College of Surgeons' risk calculator, which helps clinicians determine the chance of complications or death following surgery. They'd also like to see more physicians telling their heart failure patients about the risks, especially for surgeries that are non-essential.
"Five percent represents a high risk," Wren said. "Patients and physicians need to have better discussions about those risks."
Photo by Matthew Fournier