In a study of 100 consecu- tive cases of pathologically proven native valve IE (NVE), inclusion of these additional parameters with the existing Duke minor criteria resulted in a 10% increase in the fre- quency of cases being deemed clinically definite, with no loss of specificity. The major limitations of the erythrocyte sedi- mentation rate and C-reactive protein are that they are non- specific and particularly challenging to interpret in patients with comorbid conditions. These additional parameters have not been formally integrated into the modified Duke criteria,24 however, which are universally accepted. One minor criterion from the original Duke schema, echocardiogram consistent with IE but not meeting major criterion, was re-evaluated. This criterion originally was used in cases in which nonspecific valvular thickening was detected by transthoracic echocardiography (TTE). In a reanalysis of patients in the Duke University database (containing records collected prospectively on >800 cases of definite and possible IE since 1984), this echocardiographic criterion was used in only 5% of cases and was never used in the final analysis of any patient who underwent transesophageal echocardiogra- phy (TEE). Therefore, this minor criterion was eliminated in the modified Duke criteria.24 Finally, adjustment of the Duke criteria to require a mini- mum of 1 major plus 1 minor criterion or 3 minor criteria as a floor to designate a case as possible IE (as opposed to findings consistent with IE that fall short of definite but not rejected ) has been incorporated into the modified criteria to reduce the proportion of patients assigned to the IE possible category. This approach was used in a series of patients ini- tially categorized as possible IE by the original Duke criteria. Table 2. 