Solid cerebral microemboli and cerebrovascular symptoms in patients with prosthetic heart valves.
OBJECTIVE
Although cerebral microemboli are often detected by transcranial Doppler ultrasonography in mechanical heart valve patients, the clinical significance of such microemboli is unclear. The aim of this study was to determine the frequency and composition of cerebral microemboli in a prosthetic heart valve population and to correlate these findings to cerebrovascular symptoms, blood inflammation, and coagulation parameters.


METHODS
Seventy-six consecutive patients with a total of 81 prosthetic (54 mechanical, 27 biologic) heart valves were monitored for cerebral microemboli by multifrequency transcranial Doppler ultrasonography 1 year after valve replacement. Cerebrovascular events in the first year were recorded by a neurologist. Inflammation and coagulation markers were measured by immunoassays.


RESULTS
Microemboli were detected in mechanical heart valve patients only (28 patients, 56%). Twelve percent were solid, occurring in 17 (34%) of the mechanical heart valve population. The presence of solid cerebral microemboli was the only variable that was associated with cerebrovascular symptoms after a final regression analysis (P=0.026). The plasma monocyte chemotactic protein-1 level was raised in patients with solid microemboli (P=0.014).


CONCLUSIONS
Solid cerebral microemboli were detected by multifrequency transcranial Doppler ultrasonography in 35% of a mechanical heart valve population, and the frequency was higher in patients who experienced cerebrovascular events during the first year after valve replacement. The results suggest that the detection of solid cerebral microemboli may be helpful in predicting the risk of ischemic stroke in mechanical heart valve patients.
Skjelland
Mona
M
Department of Neurology, Rikshospitalet-Radiumhospitalet Medical Center, University of Oslo, Oslo, Norway. mona.skjelland@rikshospitalet.no
Michelsen
Annika
A
Brosstad
Frank
F
Svennevig
Jan L
JL
Brucher
Rainer
R
Russell
David
D
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020757:Amaurosis Fugax / Q000000981:diagnostic imaging / Q000453:epidemiology; D001777:Blood Coagulation; D004618:Embolism, Air / Q000000981:diagnostic imaging / Q000453:epidemiology; D005260:Female; D006350:Heart Valve Prosthesis / Q000009:adverse effects*; D006801:Humans; D015994:Incidence; D007249:Inflammation / Q000453:epidemiology; D020766:Intracranial Embolism / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D002546:Ischemic Attack, Transient / Q000000981:diagnostic imaging / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015539:Platelet Activation; D011237:Predictive Value of Tests; D012307:Risk Factors; D020521:Stroke / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D017585:Ultrasonography, Doppler, Transcranial