Heart surgery results good in low-volume hospitals

NEW YORK (Reuters Health) - The rate of in-hospital deaths after coronary artery bypass graft (CABG) surgery has steadily declined since 1997, and the proportion of CABG procedures performed at low-volume institutions has increased, according to a report in the April Archives of Surgery.

Previous studies have repeatedly demonstrated that the outcome of CABG procedures is better when performed in hospitals that have a high volume of these surgeries. Therefore, patients are often advised to seek out a high-volume center to perform their surgery.

However, the patterns observed in the current research "should dampen enthusiasm for regionalization of CABG care based solely on volume," lead investigator Dr. Rocco Ricciardi, at the Lahey Clinic in Burlington, Massachusetts, and his associates conclude.

The investigators analyzed discharge records obtained from the Agency for Healthcare Research and Quality. They took a 20-percent random sample of patients admitted to U.S. hospitals between 1988 and 2003.

The proportion of patients who underwent CABG at high volume centers -- defined as more than 500 procedures per year -- rose from 45 percent in 1988 to a peak of 63 percent in 1997, and subsequently fell to 41 percent in 2003.

In contrast, at low-volume hospitals (defined as less than 250 procedures per year), the proportion of cases dropped from 20 percent to a nadir of 11 percent, and then rose to 25 percent.

The number of high-volume centers rose from 17.7 percent in 1988 to 32.5 percent in 1997, but then fell to 15.5 percent in 2003.

Conversely, the number of low-volume centers fell from 49.6 percent in 1988 to 35.5 percent in 1997, but then rose to 52.4 percent in 2003.

During the entire period, overall CABG mortality rates steadily declined from 5.4 percent to 3.3 percent. Hospitals performing the lowest volume of CABG surgeries had the greatest improvements in survival.