Age alone influences risks for people in their eighties after heart surgery

Nov 26 2005

Patients aged 80 and older have a higher risk of death and disease than younger patients after undergoing coronary artery bypass graft (CABG) surgery or valve surgery, and age alone influences these outcomes, according to a study in the November issue of Archives of Surgery.

There were 4.2 million Americans aged 85 or older in 2000, and this number is projected to increase to 8.9 million by 2030, according to background information in the article. Approximately 40 percent of all octogenarians have symptomatic cardiovascular disease. Previous observational studies have shown that octogenarians undergoing open heart surgery for CABG or valve replacement are at higher risk for postoperative death. But until recently, no large studies have determined whether age is an independent risk factor for disease and death in octogenarians undergoing open heart surgery.

W. Michael Johnson, M.D., of Good Samaritan Hospital, Cincinnati, and colleagues conducted an eight-year hospitalization cohort study to determine whether being an octogenarian is an independent risk factor for mortality, as well as for nine other measured outcomes. Data were collected on a consecutive sample of 7,726 patients undergoing coronary artery bypass grafting or valve surgery between October 1, 1993, and February 28, 2001. There were 522 octogenarians in the study sample. The researchers controlled for 16 potential confounding variables to isolate outcome differences according to age.

"…octogenarians were found to have a higher risk for death (72 percent higher), longer length of hospitalization (3 percent higher), and a higher risk for neurologic complications (51 percent higher); they were also more likely to undergo re-operation to treat bleeding (49 percent more likely)," the authors report.

There were no significant differences between octogenarians and patients under the age of 80 in regard to kidney, lung, or gastrointestinal tract complications, returns to intensive care, or intraoperative complications--such as heart attack, hemorrhage, and irregular heartbeat.

"Like other investigators, we found that octogenarians were at higher risk for postoperative death," the authors write. "However, our results show that after controlling for differences between octogenarians and non-octogenarians, age is an independent risk factor for morbidity and mortality."

The authors point to projections that an estimated 12 million Americans will swell the ranks of octogenarians by the year 2010, as the younger population ages and life expectancy rises. "An increasing number of octogenarians undergoing coronary revascularization or valve surgery are certain to strain an already burdened health care system," they assert.

"It is, therefore, incumbent on researchers to develop more refined algorithms to predict postoperative outcomes," the authors conclude. "As this study indicates, age should be considered a component of any such algorithm."

http://jama.ama-assn.org/ and http://archsurg.ama-assn.org/