title: Clinical correlations of Doppler microembolic signals in patients with prosthetic cardiac valves: analysis of 580 cases.
abstract: BACKGROUND
  The clinical relevance of Doppler microembolic signals (MES) in patients with prosthetic cardiac valves was evaluated by merging and statistically reanalyzing patient data from four research institutions (Departments of Neurology, Universities of Aachen, Halle, and Münster, Germany; Department of Medicine and Therapeutics, University of Glasgow, Scotland, and Department of Cardiothoracic Surgery, Western Infirmary, Glasgow, Scotland).
  
  
  METHODS
  Transcranial Doppler monitoring for MES was performed over the middle cerebral arteries for 30 to 60 minutes per patient. Prevalence of neurological complications was evaluated with a standard neurological questionnaire in patients carrying the valve implant longer than 3 months (n=369).
  
  
  RESULTS
  Significant differences in MES prevalence and counts were noted among the 580 patients depending on valve type (presented with medians and [95% confidence intervals]): St Jude Medical, n=200, 72%, 4 [3 to 6]; Björk Shiley Monostrut, n=99, 92%, 133 [93 to 181]; Medtronic Hall, n=80, 47%, 1 [2 to 5]; ATS, n=61, 52%, 3 [2 to 5]; Tecna, n=38, 71%, 2 [1 to 4]; Carbomedics, n=37, 81%, 8 [5 to 13]; Carpentier-Edwards supraannular, n=54, 39%, 1 [0 to 3]; Sorin biological, n=11, 9%, 0 [0 to 0]. No relation between MES counts and valve size, international normalized ratio, patients' age, cardiac rhythm, or implant duration was noted. No significant differences in MES counts or prevalence (22 [3 to 68] versus 5 [3 to 6] and 63% versus 69%, both P>.05), in valve duration, valve position, valve type, patients' age, sex, cardiac rhythm, or international normalized ratio were evident between neurologically symptomatic (n=42) and asymptomatic patients.
  
  
  CONCLUSIONS
  MES in patients with prosthetic cardiac valves depend on the type and, in certain valve types, the position of the valve implant and possess no direct clinical significance.
authors.affiliation: Department of Neurology, Universities of Halle and Jena, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Sliwka
authors.forename: D
authors.initials: D
authors.lastname: Georgiadis
mesh_terms: D000367:Age Factors; D000925:Anticoagulants / Q000627:therapeutic use; D001021:Aortic Valve; D001705:Bioprosthesis; D001766:Blindness / Q000209:etiology; D001780:Blood Coagulation Tests; D002545:Brain Ischemia / Q000209:etiology; D002536:Cerebral Arteries / Q000000981:diagnostic imaging; D016001:Confidence Intervals; D005260:Female; D006339:Heart Rate; D006350:Heart Valve Prosthesis / Q000009:adverse effects; D006801:Humans; D002542:Intracranial Embolism and Thrombosis / Q000000981:diagnostic imaging* / Q000209:etiology; D002546:Ischemic Attack, Transient / Q000209:etiology; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve; D008991:Monitoring, Physiologic; D018908:Muscle Weakness / Q000209:etiology; D009460:Neurologic Examination; D015995:Prevalence; D011474:Prosthesis Design; D012737:Sex Factors; D013064:Speech Disorders / Q000209:etiology; D011795:Surveys and Questionnaires; D013997:Time Factors; D017585:Ultrasonography, Doppler, Transcranial
chemical_list: D000925:Anticoagulants