NEW ORLEANS – Over the years patients with prosthetic valve endocarditis treated at Cleveland Clinic tended to fare better with surgery compared to medical management, some clinicians noted. However, there was no data to confirm their observations.
“It was not recognized widely. A lot of our colleagues continued to believe it could be adequately treated with the right antibiotic,” Nabin K. Shrestha, MD, said at the IDWeek 2016 annual meeting on infectious diseases.
So Dr Shrestha and his colleagues conducted a retrospective cohort study to compare outcomes between 253 surgically treated adults and 77 others treated medically between April 2008 and December 2012. Survival from the time of treatment decision was the primary outcome.
The groups differed on some demographic and clinical factors. For example, the medically treated group was older, had fewer men, and more patients with mitral valves. “We might think the medical patients might be too sick for surgery, and that could certainly be true, but … they could have been too well for surgery too,” Dr. Shrestha said. To control for these differences between groups, the investigators performed a number of statistical analyses, including a propensity score adjusted model and reduced Cox proportion hazards model.
“Patients with PVE have a high hazard of death if treated medically,” Dr. Shrestha said, based on a 6.68 hazard ratio. The higher risk of death associated with medical treatment remained significant when adjusted for age, sex, and other factors. “Compared to surgical treatment, medical treatment was associated with a seven-fold higher hazard of death overall,” Dr. Shrestha said at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.
The medical treatment group also fared worse on a number of secondary outcomes. For example, this group had a five-fold higher risk of death during hospitalization compared to the surgery group (odds ratio, 4.65); a 12-fold higher risk of death within one year (OR, 11.70); a seven-fold higher risk of subsequent surgery for infective endocarditis (OR, 6.57); and an eight-fold higher odds of surgery for the same episode of infective endocarditis at a subsequent hospitalization (OR, 8.02).
A large sample size and setting the date of management decision as time zero to avoid survival selection bias “give us confidence in our findings.” Limitations include an inability to look at some important variables because of the retrospective design.
A meeting attendee commented that surgeons often request a patient be optimized medically prior to surgery, and asked if investigators looked at time from hospitalization to the operation.
“The median date from admission to surgery was six days in our database,” said Dr. Shrestha, who is a staff physician at the Cleveland Clinic in Ohio.
“Medical treatment overall is associated with significantly poorer outcomes in patients with PVE compared with surgical treatment,” Dr. Shrestha said. “Although some patients are not candidates for surgery, a definite diagnosis of PVE should prompt a surgical evaluation in the majority of patients.”
Dr. Shrestha reported having no disclosures.