Clinical utility of cerebral angiography in the preoperative assessment of endocarditis

Cerebral angiography is an invasive procedure utilized without supporting guidelines in preoperative evaluations of infective endocarditis (IE). It is used to identify mycotic intracranial aneurysm, which is suspected to increase the risk of intracranial bleeding during cardiac surgery. Our objectives were to: (1) assess the utility of cerebral angiography by determining which subset of IE patients benefit from its performance; and (2) identify clinical and noninvasive screening tests that can preclude the need for invasive cerebral angiography. Retrospective analysis was performed of all patients treated surgically for IE from 7/2007 to 1/2012 and discharged with medical treatment for IE from 7/2007 to 7/2009 presenting to a large academic center. Of the 151 patients who underwent cerebral angiography, mycotic aneurysm was identified in seven (prevalence=4.6%; 95% CI 2.3-9.3%). Five had viridans group streptococci as the causative IE microorganism (p=0.0017). Noninvasive imaging and particularly absence of intracranial bleed on magnetic resonance imaging conveys a negative predictive value (NPV) of 0.977 (95% CI 0.879-0.996). Absence of a focal neurologic deficit or altered mental status convey a NPV of 0.990 (95% CI 0.945-0.998) and 0.944 (95% CI 0.883-0.974), respectively. Clinical suspicion for mycotic aneurysm and thus utilization of cerebral angiography is likely necessary only in the setting of acute neurologic deficits and when noninvasive imaging demonstrates acute intracranial bleed. A novel association between viridans group streptococci and intracranial mycotic aneurysm is demonstrated.