隨著接受心臟手術的婦女數目增加，一份最新的研究指出：對婦女而言，她們極易在手術間期病發中風或死亡。在五月一日的Circulation: Journal of the American Heart Association 期刊，研究人員暗示動情激素的缺少可能是潛在的病因，然而，直至目前為止，仍無人能確切地解釋婦女更易病發的原因。
Women More Likely to Have a Stroke After Heart Surgery
Estrogen May Be the Underlying Factor
By Peggy Peck
WebMD Medical News
Reviewed by Michael W. Smith, MD
April 30, 2001 -- As the incidence of cardiac surgery grows among women, a new study shows that this group has a particularly high risk of stroke and mortality during the perioperative period. In the May 1 issue of Circulation: Journal of the American Heart Association, researchers suggest that a lack of estrogen may be the underlying cause, but at this point no one knows exactly how to account for this increased morbidity among women.
Lead author Victor G. Dávila-Román, MD, tells WebMD that even after he and his colleagues adjusted the data to account for known stroke risks such as hypertension, high cholesterol, age, and diabetes, "gender was still an independent risk factor for stroke. Women had a 21% higher risk of stroke than men did."
Dávila-Román, associate professor of medicine at Washington University School of Medicine, in St. Louis, and his colleagues studied medical records from 416,347 patients who underwent coronary bypass surgery and/or valve surgery, 32% of whom were women.
Dávila-Román says that 3.3% of the patients had a new stroke during the perioperative period. "But for women, the rate was 3.8% compared to 2.4% for men," he says. Moreover, at 30 days after surgery, the death rate for women was 5.7% compared to 3.5% for men. And for those who suffered a perioperative neurological event, mortality was significantly higher for women than men (32% vs. 28%).
Study co-author Charles W. Hogue Jr. MD, tells WebMD that it is very difficult to pinpoint a single reason for the increased stroke risk seen among women. But he says that estrogen is probably a factor.
According to Hogue, animal studies suggest that estrogen may protect neurons from injury. He says there are also data to suggest that estrogen may limit the extent of neurologic injury when a stroke occurs.
Nieca Goldberg, MD, spokesperson for the American Heart Association, tells WebMD that the study is "one in a continued series of research that illustrates that when it comes to [cardiovascular disease] women continue to have higher morbidity and mortality. But we still have to do the research to find out why."
But even though Goldberg, who heads the women's cardiac program at Lenox Hill Hospital in New York, says the new findings are interesting, she is unconvinced about the role of estrogen. "There is a big hole in this study, and that is lack of information about hormone replacement," she says.
The data in this study come from the Society of Thoracic Surgery's National Cardiac Surgery Database, which includes records from operations performed at a large number of hospitals nationwide. Unfortunately, those records do not include information about the use of hormone replacement therapy, says Dávila-Román. "So we don't really know how many of these women were taking estrogen at the time of their surgery," he says.
Nonetheless, both Hogue and Dávila-Román hypothesize that hormonal status may be the best explanation for the difference in stroke risk. To test this theory, they recently received funds from the National Institutes of Health to begin a placebo-controlled trial of the effect of estrogen on women undergoing heart surgery. Dávila-Román says that women will be randomized to either estrogen treatment or placebo before, during, and immediately after cardiac surgery. "Before and after surgery, we will use an estrogen or placebo patch, and during surgery, we will give intravenous estrogen or placebo," he says.