New Study Demonstrates the Clinical and Economic Challenges of Staphylococcus Aureus Infections

ROCKVILLE, Md. -- Nabi Biopharmaceuticals announced results from a study presented at the 2004 annual meeting of the American Heart Association that showed that Staphylococcus aureus bacteremia (Staphylococcus aureus bloodstream infections) in patients with cardiovascular devices significantly increased the incidence of medical complications, treatment costs and death.

The study evaluated heart disease patients with cardiovascular devices such as prosthetic valves, pacemakers and defibrillators, ventricular assist devices, intra-aortic balloon pumps and non-hemodialysis intravascular stents/grafts who developed S. aureus bacteremia (SAB). Among the 122 patients evaluated, 44 percent experienced serious complications as a result of their infection and 35 percent died within 12 weeks. One group consisted of patients with a cardiovascular device who had S. aureus infection when they were admitted to the hospital. The other group consisted of patients with a cardiovascular device who developed SAB during the hospitalization. The study also demonstrated that SAB was associated with substantial medical costs with individual patients incurring a mean cost of $82,300 for a hospital-acquired infection and $47,390 when the patient was admitted to the hospital with the infection.

This study was sponsored by Nabi Biopharmaceuticals and executed by investigators from Duke Clinical Research Institute, Duke University Medical Center, Durham, N.C. and Health Economics Consulting, Annapolis, Md..

S. aureus Infections Have Significant Clinical Impact

The study included patients who were identified prospectively with both SAB and a cardiovascular device and found that health complications and death occurred frequently in these patients. Patients with prosthetic valves experienced the highest rates of complications and deaths with 25 patients experiencing serious health complications (60 percent) and 19 patients dying (45 percent) within 12 weeks. The second highest number of complications and deaths occurred among patients with pacemaker and/or defibrillator devices with 13 patients experiencing complications (38 percent) and 11 patients dying (33 percent) within 12 weeks. Finally, among patients with other cardiovascular devices, such as ventricular assist devices, intra-aortic balloon pumps and non-hemodialysis intravascular stents/grafts, 16 patients experienced serious complications (35 percent) and 13 patients died (28 percent) within 12 weeks.

S. aureus Infections Have Significant Economic Impact

The study also demonstrated that SAB was associated with substantial medical costs. Patients with prosthetic valves incurred a mean cost of $45,506 among those who were admitted to the hospital with SAB and a mean cost of $126,925 among those who developed a hospital-acquired infection. Patients with pacemaker and/or defibrillator devices incurred mean costs of $46,183 for those admitted with SAB and $55,007 for those with hospital-acquired SAB. (Costs for inpatients were calculated from the day of admission for patients admitted with suspected SAB and from the day of the first positive blood culture for patients with hospital-acquired SAB. Costs include re-hospitalization due to infection and infection-related outpatient costs.) Finally, patients with other cardiovascular devices, such as ventricular assist devices, intra-aortic balloon pumps and intravascular stents/grafts incurred mean costs of $55,779 for those admitted with SAB and $74,375 for those who acquired SAB during their hospital stay

"This study adds to the significant growing body of evidence that underscores the need for better prevention and treatment options for the patients most at risk of acquiring S. aureus infections," said Thomas H. McLain, chairman, chief executive officer and president, Nabi Biopharmaceuticals. "Nabi is committed to the continued development of StaphVAX, our conjugate vaccine in a confirmatory Phase III study, as a potential new option to help prevent the deadly and costly consequences of S. aureus infections in patients at risk for developing these infections, such as heart disease patients with cardiovascular devices."

Source: Nabi Biopharmaceuticals