Evaluating the Diagnostic Performance of DSA and CTA for Intracranial Mycotic Aneurysms in Patients with Infective Endocarditis Presenting with Acute Ischemic Strokes

Introduction: Infective endocarditis can lead to serious neurological complications, including acute ischemic stroke (AIS) and intracranial mycotic aneurysms (ICMAs). The early and accurate detection of ICMAs is critical for patient management, particularly in surgical planning for valve replacement. While digital subtraction angiography (DSA) is considered the gold standard for detecting ICMAs, the utility of noninvasive imaging modalities, such as CTA, is less well defined. This study aims to evaluate the diagnostic yield of DSA compared to CTA in detecting ICMAs in patients with IE and AIS.

Methods: A retrospective analysis was conducted on 53 patients with a diagnosis of IE and AIS who underwent evaluation by CTA and subsequent confirmatory DSA. Patient demographics, clinical characteristics, comorbidities, and the presence of ICMAs were recorded. The primary outcome was the diagnostic yield of CTA in identifying ICMAs compared to DSA, focusing on aneurysm detection and size.

Results: Of the 53 patients, 8 had ICMAs. CTA detected ICMAs in 7 out of 8 patients (87.5%), while DSA identified additional aneurysms in 1 patient (12.5%) that were missed by CTA. In one case, DSA detected two ICMAs (1.8 mm and 2 mm) arising from the M4 branches of the right middle cerebral artery, which were not visible on CTA. Additionally, DSA provided more precise measurements of aneurysm size and revealed a second aneurysm in a patient previously identified with a single aneurysm on CTA. The aneurysms missed by CTA were smaller than 3 mm in size. The presence of ICMAs was associated with younger age and higher rates of intravenous drug use, though these findings were not statistically significant.

Conclusion : This study confirms that DSA is superior to CTA for detecting smaller ICMAs ( < 3 mm) in patients with IE and AIS. Despite the high sensitivity of CTA for larger aneurysms, DSA remains the gold standard for identifying smaller or more distal aneurysms, which are prone to rupture. Early and accurate detection of ICMAs is crucial for timely intervention and optimal patient outcomes.