Cerebral emboli during left heart catheterization may cause acute brain injury.

AIMS Left heart catheterization carries a risk for cerebral complications. The aims of this prospective study were to determine the frequency and composition of catheterization-related cerebral microemboli and to detect cerebral morphological changes and acute cognitive impairment due to catheterization. METHODS AND RESULTS Forty-seven unselected patients undergoing elective left heart catheterization, either by transradial or by transfemoral access, were monitored for cerebral microemboli using multifrequency transcranial Doppler. Cerebral magnetic resonance imaging (MRI) with diffusion-weighted imaging sequences and neuropsychological assessments were carried out on the day before and the day after catheterization. A median number of 754 cerebral microemboli were detected: 92.1% were gaseous and 7.9% were solid. New cerebral lesions were observed in 15.2% of the transradial, but none of the transfemoral, catheterization patients (P=0.567). These lesions were significantly associated with a higher number of solid microemboli (P=0.016) and a longer fluoroscopy time (P=0.039). There was also a significantly higher number of solid microemboli during transradial than during transfemoral catheterization (P=0.012). Cognitive impairment following the investigations was associated with the degree of pre-catheterization cerebral MRI injury (P=0.03). CONCLUSION During left heart catheterization, cerebral microemboli, especially those which are solid, may damage the brain. Cardiac catheterization may therefore pose a greater risk for the brain than previously acknowledged.