title: Relationship of quantitative parameters of myocardial perfusion SPECT and ventricular arrhythmia in patients receiving cardiac resynchronization therapy.
abstract: BACKGROUND
  Ventricular arrhythmia is the major cause of sudden cardiac death for patients with heart failure, including those receiving implantation of cardiac resynchronization therapy (CRT). The purpose of this study was to assess the value of myocardial perfusion SPECT (MPS) in predicting ventricular arrhythmia for patients with CRT.
  
  
  METHODS
  Fifty-one patients (35 males, mean age 64 ± 12 years) who had received CRT for at least 6 months were enrolled for resting gated MPS. Three main quantitative parameters of MPS, including extent of myocardial scar, left ventricular ejection fraction (LVEF) and LV dyssynchrony (phase SD), were generated by Emory Cardiac Toolbox. Using the recorded ventricular arrhythmia in the device, including ventricular tachycardia (VT) and ventricular fibrillation (VF), as the primary end point, the value of quantitative parameters of MPS in predicting the development of VT/VF was assessed.
  
  
  RESULTS
  Twenty (39 %) of the 51 patients developed VT/VF during the follow-up (15.3 ± 12.7 months). The patients with VT/VF had significantly lower LVEF (24 ± 12 vs. 36 ± 17 %, p < 0.005), larger scar areas (36 ± 19 vs. 22 ± 12 %, p < 0.05) and larger phase SD (57° ± 20° vs. 43° ± 17°, p < 0.01). When categorizing the patients by the median values of LVEF, scar and phase SD, univariate regression analysis showed that lower LVEF (<29 %), larger scar (>23 %) and larger phase SD (>50°) were related to the development of VT/VF (p = 0.006, 0.011 and 0.064, respectively). However, only LVEF was marginally significant as an independent predictor of VT//VF on multivariate regression analysis (p = 0.0573). Survival analysis with Kaplan-Meier curves showed that the survival probability for VT/VF in those with LVEF >29 %, scar areas <23 % and phase SD < 50° was significantly better than in the others (HR 5.16, 95 % CI 1.20-22.16) by log-rank test (χ (2) = 5.9894, p = 0.014).
  
  
  CONCLUSIONS
  Lower LVEF, larger scar and/or more dyssynchrony assessed by MPS were related to the development of ventricular arrhythmia for patients with CRT, and further defibrillator implantation may be considered for these patients.
authors.affiliation: Department of Nuclear Medicine, Show Chwan Memorial Hospital, Changhua, Taiwan.
authors.forename: Po-Nien
authors.initials: PN
authors.lastname: Hou
authors.affiliation: Department of Nuclear Medicine, Taichung Veterans General Hospital, Taichung, Taiwan.|Department of Medical Imaging and Radiological Sciences, Central Taiwan University of Science and Technology, Taichung, Taiwan.
authors.forename: Shih-Chuan
authors.initials: SC
authors.lastname: Tsai
authors.affiliation: Department of Nuclear Medicine, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Wan-Yu
authors.initials: WY
authors.lastname: Lin
authors.affiliation: Division of Cardiology, Department of Medicine, Fong Yuan Hospital of the Ministry of Health and Welfare, Taichung, Taiwan.
authors.forename: Chien-Ming
authors.initials: CM
authors.lastname: Cheng
authors.affiliation: Cardiovascular Center, Taichung Veterans General Hospital, 1650 Taiwan Boulevard Sect. 4, Taichung, 40705, Taiwan.
authors.forename: Kuo-Feng
authors.initials: KF
authors.lastname: Chiang
authors.affiliation: Cardiovascular Center, Taichung Veterans General Hospital, 1650 Taiwan Boulevard Sect. 4, Taichung, 40705, Taiwan.
authors.forename: Yu-Cheng
authors.initials: YC
authors.lastname: Chang
authors.affiliation: Cardiovascular Center, Taichung Veterans General Hospital, 1650 Taiwan Boulevard Sect. 4, Taichung, 40705, Taiwan. golden@vghtc.gov.tw.|Institute of Clinical Medicine, and Cardiovascular Research Institute, Department of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan. golden@vghtc.gov.tw.
authors.forename: Jin-Long
authors.initials: JL
authors.lastname: Huang
authors.affiliation: Department of Medical Imaging and Radiological Sciences, Central Taiwan University of Science and Technology, Taichung, Taiwan. 106143@gmail.com.|Department of Nuclear Medicine, Chang Bing Show Chwan Memorial Hospital, 6 Lukon Road, Lukong Town, Changhua, 505, Taiwan. 106143@gmail.com.
authors.forename: Guang-Uei
authors.initials: GU
authors.lastname: Hung
authors.affiliation: Divisions of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Shih-Ann
authors.initials: SA
authors.lastname: Chen
authors.affiliation: Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, USA.
authors.forename: Ji
authors.initials: J
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000009:adverse effects* / Q000401:mortality; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D011379:Prognosis; D016016:Proportional Hazards Models; D012044:Regression Analysis; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000401:mortality; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
keywords: Cardiac resynchronization therapy; Phase analysis; Quantitation; SPECT; Ventricular arrhythmia