CABG Mortality Rates Remain Flat

The mortality rate for isolated coronary artery bypass graft surgeries at California's hospitals remained flat in 2011 while the number of the procedures dropped in favor of less invasive forms of treatment.

According to data compiled by the Office of Statewide Health Planning and Development, the overall mortality rate among the 122 hospitals surveyed was 2.01% for 2011, virtually unchanged from the 2% rate reported in 2010 and slightly higher than the 1.9% mortality rate reported in 2009.

Altogether, there were 249 deaths connected to the 12,399 isolated CABGs performed by California hospitals in 2011. In 2010, 251 patients died in connection with the 12,548 procedures performed.

Nonetheless, the current mortality rates are dramatically lower than the 2.91% rate in 2003, when hospitals were first required to disclose their data. Overall, the mortality rate has dropped some 31% over the last decade.

“We believe there is still room for improvement though...rates have essentially flattened out in the last couple years,” said OSHPD spokesperson David Byrnes. He noted that states such as Massachusetts and New York have been able to achieve rates lower than 2%.

But hospitals face an uphill battle on that front, given the number of CABGs being performed has declined dramatically in recent years. The number of isolated CABGs performed in California decreased 58% between 1997 and 2012, while volume for the rarer non-isolated procedure dropped 20%.

Byrnes observed that the decrease in volume has a lot to do with a shift toward percutaneous coronary interventions, which are primarily angioplasties with stent placements. However, the use of that procedure has also dipped as clinical studies have indicated other non-surgical interventions may be just as effective.

“The fact that many of our hospitals are operating on small numbers of patients each year may prevent them from gaining the experience to achieve dramatically lower mortality rates,” Byrnes said.

Overall mortality rates at the hospitals submitting data ranged from zero to 8.18% after adjusting for some 25 different health and demographic factors. However, only one hospital, AHMC Anaheim Regional Medical Center, performed below the often wide-ranging confidence intervals for the hospitals.

Along with the mortality rates, post-operative stroke rates also remained flat at 1.31%, compared to 1.32% in 2010. That's somewhat better than the 1.4% national rate reported by the Society of Thoracic Surgeons, according to OSHPD.

One hospital in California had better than average risk-adjusted stroke rates – Sutter Memorial Hospital in Sacramento. Four hospitals had worse-than-average rates, including Hoag Memorial Hospital Presbyterian in Newport Beach.

Readmissions within 30 days of discharge did drop, to 12.97%, compared to 13.15% in 2010, a reduction of 1.4%. 

Two hospitals had better-than-average risk-adjusted readmission rates, while four had below-average rates.

Related: CABG Mortality Inches Up Statewide