HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Christof Schmid Dieter Hammel Hans H. Scheld Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Nabavi, D. G. Articles by Ringelstein, E. B. Search for Related Content PubMed PubMed Citation Articles by Nabavi, D. G. Articles by Ringelstein, E. B. Related Collections Cerebral protection Mechanical Circulatory Assistance

J Thorac Cardiovasc Surg 2003;126:160-167
© 2003 The American Association for Thoracic Surgery

Cardiopulmonary support and physiology

Doppler microembolic load predicts risk of thromboembolic complications in Novacor patients

^a Department of Neurology, University of Münster, Münster, Germany
^b Department of Cardiothoracic Surgery, University of Münster, Münster, Germany

Received for publication May 8, 2002; revisions received August 20, 2002; accepted for publication August 22, 2002.

^* Address for reprints: Darius G. Nabavi, MD, Department of Neurology, University of Münster, Albert Schweitzer-Str. 33, 48129 Münster, Germany
nabavi{at}uni-muenster.de

OBJECTIVE: Left ventricular assist devices have become an established method to bridge patients with end-stage cardiac failure to heart transplantation. Besides infection and bleeding, thromboembolism represents one of the most serious complications. We evaluated the value of microembolic signals in predicting thromboembolic events for individual patients and distinctive left ventricular assist device periods.

METHODS: Twenty patients (14 male) aged 23-57 years supported with the Novacor N100 left ventricular assist device were enrolled in this study. All patients were on effective anticoagulation, 12 patients additionally received antiplatelet therapy. Unilateral detection of microembolic signals was performed once weekly by insonation of the middle cerebral artery using transcranial Doppler sonography for 30 minutes duration. Evidence of clinically manifest thromboembolic events was based on regular questionnaires, clinical examinations, and results of diagnostic procedures.

RESULTS: During a cumulative follow-up of 3876 left ventricular assist device days, 44 thromboembolic complications occurred (incidence, 1.1%) in 15 out of 20 patients. A total of 360 transcranial Doppler sonography monitorings (range, 5-34 per patient) were performed with an overall microembolic signals prevalence of 35.3% and a microembolic signal mean of 2.3 ± 9.2 per examination. There was a highly significant correlation between the individual microembolic signal activity and the respective incidence of clinical thromboembolism (r = 0.61-0.9; P < .01). Patients with additional antiplatelet treatment had significantly less thromboembolic complications (0.7%) and lower microembolic signal prevalence (18.3%) than those without (2.8% and 65.4%, respectively). Individual patients and left ventricular assist device months with clinical thromboembolization could be identified using the microembolic signal activity with moderate positive (0.37-0.7) and high negative predictive values (0.82-1.0).

CONCLUSIONS: The amount of microembolic signals, serially detected in patients with the Novacor left ventricular assist device, is significantly associated with their incidence of embolic complications. The high negative predictive value of microembolic signals enables to identify those patients and left ventricular assist device periods with particularly low risk of clinical thromboembolization.

This article has been cited by other articles:

				R. Dittrich and E. B. Ringelstein Occurrence and Clinical Impact of Microembolic Signals During or After Cardiosurgical Procedures Stroke, February 1, 2008; 39(2): 503 - 511. [Abstract] [Full Text] [PDF]

				N. H. Thoennissen, M. Schneider, A. Allroggen, M. Ritter, R. Dittrich, C. Schmid, H. H. Scheld, E. B. Ringelstein, and D. G. Nabavi High level of cerebral microembolization in patients supported with the DeBakey left ventricular assist device J. Thorac. Cardiovasc. Surg., October 1, 2005; 130(4): 1159 - 1166. [Abstract] [Full Text] [PDF]