title: Cryoablation during left ventricular assist device implantation reduces postoperative ventricular tachyarrhythmias.
abstract: BACKGROUND
  The number of patients undergoing implantation of a HeartMate II left ventricular assist device (LVAD; Thoratec Corporation, Pleasanton, Calif) is rising. Ventricular tachyarrhythmia (VA) after placement of the device is common, especially among patients with preoperative VA. We sought to determine whether intraoperative cryoablation in select patients reduces the incidence of postoperative VA.
  
  
  METHODS
  From January 2009 through September 2010, 50 consecutive patients undergoing implantation of the HeartMate II LVAD were examined. Fourteen of these patients had recurrent preoperative VA. Of those patients with recurrent VA, half underwent intraoperative cryoablation (Cryo: n = 7) and half did not (NoCryo: n = 7). Intraoperatively, patients underwent localized epicardial and endocardial cryoablation via LVAD ventriculotomy. Cryothermal lesions were created to connect scar to fixed anatomic borders in the region of clinical VA. Demographics, risk factors, intraoperative features, and outcomes were analyzed to investigate the feasibility of cryoablation.
  
  
  RESULTS
  Thirty-day mortality remained low (n = 1, 2%) among all LVAD recipients. There were no differences in risk factors between groups except that preoperative inotropes were less prevalent in Cryo patients (P = .09). Compared with NoCryo, the Cryo group had significantly decreased postoperative resource use and complications (P < .05). Recurrent postoperative VA did not develop in any of the Cryo patients (P = .02).
  
  
  CONCLUSIONS
  Postoperative VA can be minimized by preoperative risk assessment and intraoperative treatment. Localized cryoablation in select patients offers promising early feasibility when performed during HeartMate II LVAD implantation. Further prospective analysis is required to investigate this novel approach.
authors.affiliation: Division of Thoracic and Cardiovascular Surgery, Department of Surgery, University of Virginia Health System, Charlottesville, VA 22908, USA.
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Mulloy
authors.forename: Castigliano M
authors.initials: CM
authors.lastname: Bhamidipati
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Stone
authors.forename: Gorav
authors.initials: G
authors.lastname: Ailawadi
authors.forename: James D
authors.initials: JD
authors.lastname: Bergin
authors.forename: Srijoy
authors.initials: S
authors.lastname: Mahapatra
authors.forename: John A
authors.initials: JA
authors.lastname: Kern
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D016009:Chi-Square Distribution; D003452:Cryosurgery / Q000009:adverse effects / Q000401:mortality; D005240:Feasibility Studies; D005260:Female; D006353:Heart-Assist Devices / Q000009:adverse effects*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D055502:Secondary Prevention; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000401:mortality / Q000517:prevention & control*; D013997:Time Factors; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D014693:Ventricular Fibrillation / Q000175:diagnosis / Q000401:mortality / Q000517:prevention & control*; D016277:Ventricular Function, Left