Effect of platelet inhibitors on thromboembolism after implantation of a Novacor N100--preliminary results.
BACKGROUND
Left-ventricular assist device implantation (LVAD) is still associated with thromboembolism as the optimal anticoagulation is still unclear. We report on the effects of adding platelet inhibitors to our anticoagulation regimen in our Novacor LVAD program.


METHODS
Oral platelet aggregation inhibitors (aspirin 330 mg + dipyridamole 75 mg, three times per day) were added to the heparin/phenprocoumon treatment in 9 patients starting on postoperative day 3 to 7 (group A). Of the previous 41 patients, the last 20 patients served as a control group (group B), to reduce any learning curve effect.


RESULTS
The mean interval of mechanical support between the two groups was comparable (group A vs B: 148 +/- 127 vs 104 +/- 61 days, n.s.). Accordingly, the cumulative support was much lower in group A (1051 days) as compared to group B (2091 days). In group B, 10 patients (50%) developed clinically evident thromboembolism. The number of events ranged from 1 to 10 (mean 1.4 +/- 2.3), with a total of 32. With addition of platelet inhibitors, the incidence of cerebral embolism dramatically dropped, as only one patient presented with transient ischemic attacks in group A (p < 0.05). Thoracic bleeding as defined by excessive drainage losses requiring redo thoracotomy did not increase (group A vs B: 22% vs 20%, n.s.).


CONCLUSIONS
Addition of platelet inhibitors to heparin/phenprocoumon effectively prevents thromboembolism. However, platelet inhibitors should be postponed until sufficient hemostasis is achieved, since too early administration is associated with an increased risk of bleeding.
Schmid
C
C
Department of Thoracic and Cardiovascular Surgery, Westfalian Wilhelms University, Münster, Germany.
Weyand
M
M
Hammel
D
D
Deng
M C
MC
Nabavi
D
D
Scheld
H H
HH
D000925:Anticoagulants / Q000627:therapeutic use; D001241:Aspirin / Q000627:therapeutic use; D016022:Case-Control Studies; D004176:Dipyridamole / Q000627:therapeutic use; D005260:Female; D006353:Heart-Assist Devices; D006493:Heparin / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D010644:Phenprocoumon / Q000627:therapeutic use; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D013923:Thromboembolism / Q000209:etiology / Q000517:prevention & control*
D000925:Anticoagulants; D010975:Platelet Aggregation Inhibitors; D004176:Dipyridamole; D006493:Heparin; D010644:Phenprocoumon; D001241:Aspirin