Cerebrovascular accidents in patients with a ventricular assist...

Cerebrovascular accidents in patients with a ventricular assist device
Hiroyuki Tsukui, MD, PhDa,*, Adib Abla, MSa, Jeffrey J. Teuteberg, MDb, Dennis M. McNamara, MDb, Michael A. Mathier, MDb, Linda M. Cadaret, MDb, Robert L. Kormos, MDa

a Division of Cardiothoracic Surgery, Heart, Lung, and Esophageal Institute, University of Pittsburgh Medical Center, Pittsburgh Pa.
b Division of Cardiology, University of Pittsburgh Medical Center, Pittsburgh Pa.

Poster Presentation at the Twenty-sixth Annual Meeting of the Western Thoracic Surgical Association, Sun Valley, Idaho, June 21–24, 2006.

Received for publication June 19, 2006; revisions received December 2, 2006; accepted for publication February 14, 2007.

* Address for reprints: Hiroyuki Tsukui, MD, PhD, Division of Cardiothoracic Surgery, Heart, Lung, and Esophageal Institute, University of Pittsburgh Medical Center, Suite C-700, 200 Lothrop St, Pittsburgh PA, 15213. (Email: [email protected]).

Objective: A cerebrovascular accident is a devastating adverse event in a patient with a ventricular assist device. The goal was to clarify the risk factors for cerebrovascular accident.

Methods: Prospectively collected data, including medical history, ventricular assist device type, white blood cell count, thrombelastogram, and infection, were reviewed retrospectively in 124 patients.

Results: Thirty-one patients (25%) had 48 cerebrovascular accidents. The mean ventricular assist device support period was 228 and 89 days in patients with and without cerebrovascular accidents, respectively (P < .0001). Sixty-six percent of cerebrovascular accidents occurred within 4 months after implantation. Actuarial freedom from cerebrovascular accident at 6 months was 75%, 64%, 63%, and 33% with the HeartMate device (Thoratec Corp, Pleasanton, Calif), Thoratec biventricular ventricular assist device (Thoratec Corp), Thoratec left ventricular assist device (Thoratec), and Novacor device (WorldHeart, Oakland, Calif), respectively. Twenty cerebrovascular accidents (42%) occurred in patients with infections. The mean white blood cell count at the cerebrovascular accident was greater than the normal range in patients with infection (12,900/mm3) and without infection (9500/mm3). The mean maximum amplitude of the thrombelastogram in the presence of infection (63.6 mm) was higher than that in the absence of infection (60.7 mm) (P = .0309).

Conclusions: The risk of cerebrovascular accident increases with a longer ventricular assist device support period. Infection may activate platelet function and predispose the patient to a cerebrovascular accident. An elevation of the white blood cell count may also exacerbate the risk of cerebrovascular accident even in patients without infection. Selection of device type, prevention of infection, and meticulous control of anticoagulation are key to preventing cerebrovascular accident.

Abbreviations and Acronyms CVA = cerebrovascular accident; HIT = heparin-induced thrombocytopenia; INR = international normalized ratio; LVAD = left ventricular assist device; MA = maximum amplitude; POD = postoperative day; PTT = prothrombin time; TEG = thromboelastogram; TIA = transient ischemic attack; VAD = ventricular assist device