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| |  Study Finds Stroke After Heart Bypass Surgery More Common and Serious SAN FRANCISCO, Dec. 18, 1996 -- Instances of stroke, the nation's third leading cause of death, and related physical or intellectual deterioration are significantly more common and serious after coronary bypass surgery than previously believed, according to a new study summarized in the lead article of tomorrow's New England Journal of Medicine. Previous research studies put the chance of stroke or adverse cerebral outcome following this type of surgery as low as one-half of one percent. But a major study at 24 leading U.S. medical institutions that are members of an international network of medical investigators found that the rate is more than 10 times higher: six in every 100 patients studied suffered new and severe neurologic effects, including death, stroke or substantial deterioration of intellectual function. Dennis T. Mangano, Ph.D., MD, the senior author of the study entitled "Adverse Cerebral Outcomes After Coronary Bypass Surgery," said, "This significantly higher incidence of adverse cerebral outcome may be just the tip of the iceberg. Another 25 percent to 75 percent of coronary bypass surgery patients are likely to experience some degree of impairment of memory and concentration during the hospital stay, whereas 10 percent of these will have problems for the rest of their lives." The human and financial cost implications of the research are tremendous. For example, while 9 of 10 coronary bypass surgery patients typically return home soon after surgery, only 3 of 10 patients who suffer stroke return home. The other seven require more protracted care at specialized facilities. "Many of these patients will experience extended separation from family and require prolonged and expensive treatment," said Dr. Mangano. "The emotional toll on patients and their families is enormous. "The economic impact of stroke or other adverse cerebral outcomes is excessive and must be controlled," added Dr. Mangano. "For example, we found that patients with strokes will require at least twice as much intensive care and remain in the hospital for nearly a month after surgery compared to one week for patients without strokes. This additional hospitalization immediately increases the nation's annual medical bill by more than $400 million, while an array of long-term expenses for treatment and rehabilitation following hospitalization could increase the total annual cost to $4 billion." Researchers found that one of the major factors that raises the odds of stroke after bypass surgery is age. For those above the age of 70, which is the median age for patients undergoing coronary bypass surgery, the odds of a severe stroke rises dramatically. Dr. Mangano and Dr. Gary Roach, first author of the study concluded that "In light of this phenomenon and the overall aging of America demographic trend, we need to develop new diagnostic and therapeutic steps to reduce the human and financial toll." A defensive tactic suggested by the authors is to closely monitor the aorta prior to surgery. "A major risk factor in bypass surgery is the presence atherosclerotic or fatty plaque in the region of the aorta where surgical clamps are used which can dislodge the plaque from the arterial wall, allowing the plaque to go directly to the brain and cause a stroke," said Dr. Roach. "By identifying the presence and location of these plaques before the operation, we may be able to immediately reduce the number of strokes following coronary bypass surgery." Conducted by San Francisco-based Multicenter Study of Perioperative Ischemia Research Group (McSPI), an international network of investigators and academic centers, the study was the first multi-institutional, prospective examination of stroke and other neurological deficits following cardiac surgery. The three-fold objective was: * to determine the incidence of both stroke and significant intellectual and/or physical impairment; * to identify the independent predictors of these adverse cerebral outcomes; and * to define their economic impact, as measured by the length of hospital stay and the need for intensive intermediate or long-term care. The study examined more than 2100 patients who underwent heart bypass surgery at 24 major U.S. medical centers including academic centers at Stanford, Harvard, NYU, Yale, Michigan and Emory; specialized institutions such as the Texas Heart Institute and the Cleveland Clinic; Federal VA hospitals; private institutions such as Cedars-Sinai in Los Angeles and the nation's largest health maintenance organization, Kaiser Permanente. Data for the study was collected and analyzed between September, 1991 and September, 1995. In the study, patients were evaluated for two general categories of neurologic outcome: Type I -- death or non-fatal stroke, transient ischemic attack or stupor or coma at discharge; and Type II -- a new deterioration in intellectual function, memory deficit, or seizures. Adverse cerebral outcomes occurred in 129 of the patients (6.1 percent). A total of 3.1 percent of the patients had Type I neurologic outcomes (8 died of cerebral injury, 55 had nonfatal strokes, 2 had transient ischemic attacks and 1 had stupor) and 3 percent had Type II outcomes (55 had deterioration of intellectual function and 8 had seizures). The study concluded that adverse cerebral outcomes after coronary bypass surgery are relatively common and serious and are associated with substantial increases in mortality, the duration of hospitalization and the use of intermediate or long-term care facilities. It also advised that new diagnostic and therapeutic strategies be developed to lessen perioperative cerebral injury. Founded in 1987 by Dr. Mangano, McSPI is a research network of approximately 300 investigators and 160 academic centers in North America, Europe, Asia, Africa and India. Its members conduct unbiased, large-scale clinical trials involving treatments and therapies that reduce the occurrences of ischemic injury from surgery. McSPI is the research arm of San Francisco-based Ischemia Research & Education Foundation, an independent, nonprofit medical research organization and think tank dedicated to saving lives and economic resources through unbiased scientific research that focuses on prevention of ischemic injury such as heart attack and stroke in high-risk patients undergoing surgery.
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