Performance league tables are linked to lower death rates after major heart surgery

October 05, 2017

The findings are based on almost 26,000 patients who had coronary artery bypass surgery (CABG) for the first time between1997 to 2005, in the north west of England.

Thirty different surgeons in four major NHS sites performed CABG during this eight year period.

The research team looked for changes in expected and predicted death rates, and for any evidence that surgeons were taking on less complicated or risky cases to "enhance" their figures, as opponents of public disclosure had suggested.

The report of the public enquiry into children's death rates at Bristol Royal Infirmary was published in 2001. One of its key recommendations was that the performance of individual heart surgeons should be made public.

The research team therefore divided the eight years into surgery carried out before (1997 to 2001) and after (2001 to 2005) public disclosure.

The figures showed the death rate for CABG patients after public disclosure was significantly lower than it had been before.

The death rate fell from 2.4% of all CABG patients to 1.8%, while the predicted death rate steadily rose from 3 to 3.5%, suggesting that more complicated/elderly cases were being taken on.

When the levels of risk for each patient were assessed, the results showed a significantly higher proportion of "high risk" patients undergoing surgery in the period after public disclosure.

The proportions of elderly patients aged over 80, and those with kidney disease, a recent heart attack, or peripheral vascular disease all significantly increased.

"If publication of surgical mortality data had driven surgeons to turn down significant numbers of high risk patients we would expect to see that reflected in the number of high risk cases coming to surgery," say the authors.

"This study suggests that the effect may not be as large as is feared," they add.

"If public disclosure can drive data collection and analysis, but does not create significant risk averse behaviour, its introduction may be beneficial in other areas of medicine," they conclude.


Aspirin works by causing platelet inhibition in the blood, which means that platelets cannot stick together and this slows the formation of blood clots that cause a heart attack or stroke.

"This does happen in women, but it doesn't happen in as many women and it's not as effective," Dorsch said. The testing device uses an optical sensor to "see" what percentage of the platelets in the blood sample clump together. Anything less than 40 percent platelet inhibition is considered aspirin resistant.

"We really don't know the mechanism," Dorsch said. "It could be that women have a more active platelet system in the body so it's less likely that platelet action would be inhibited."

In the future, researchers hope to look at aspirin therapy outcomes in women only and see if those outcomes can be changed. The majority of testing for aspirin therapy has been on men, so not much is known about how women respond.

"Heart disease is the number one killer of women in the United States. Future research should be aimed at finding out the cause of this increase in aspirin resistance and the effect on outcomes in women with heart disease." Dorsch said.

The study was funded by the National Institutes of Health.

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