A comparative study of 48 host valve and 24 prosthetic valve endocarditis cases.

Forty-eight cases of host valve endocarditis and 24 cases of prosthetic valve endocarditis occurring during a concurrent period of time were analyzed to assess differences between the two groups. The over-all incidence of prosthetic valve endocarditis during this 40 month period was 4.4%. The symptoms and signs in both groups were similar, except that PVE patients had more frequent occurrences of changing heart murmurs and splenic and cerebral emboli. Spleen scans may be helpful in the diagnosis of selected cases of culture-negative prosthetic valve endocarditis. There was no significant difference between the two groups for the various infecting microorganisms. However, the culture-negative prosthetic valve group had a mortality rate of 77.7% compared to 46.2% for the host valve group. In the HVE patients the oral cavity or urinary tract was the probable source of infection in 50.0% of the patients. In about one third of HVE cases, there was strong evidence that the infection was related to a therapeutic procedure, whereas nearly half of the PVE patients had clinical evidence of an extracardiac infection at the time of open-heart surgery. We emphasize the need for good pre- and postoperative surveillance to eliminate possible predisposing infections and appropriate antibiotic prophylaxis in all patients with valvular disease at times of risk. The survival rate in patients with prosthetic valve endocarditis was highest in those patients who received "appropriate" antibiotics and, if significant congestive heart failure was present, surgical intervention was necessary.