RT Journal Article SR Electronic T1 Can LV Dyssynchrony as Assessed with Phase Analysis on Gated Myocardial Perfusion SPECT Predict Response to CRT? JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1104 OP 1111 DO 10.2967/jnumed.107.039925 VO 48 IS 7 A1 Maureen M. Henneman A1 Ji Chen A1 Petra Dibbets-Schneider A1 Marcel P. Stokkel A1 Gabe B. Bleeker A1 Claudia Ypenburg A1 Ernst E. van der Wall A1 Martin J. Schalij A1 Ernest V. Garcia A1 Jeroen J. Bax YR 2007 UL http://jnm.snmjournals.org/content/48/7/1104.abstract AB Cardiac resynchronization therapy (CRT) is now a well-recognized therapeutic option for patients with end-stage heart failure. However, not all patients respond to CRT, and, therefore, preimplantation identification of responders is desirable. The aim of the present study was to investigate whether the degree of left ventricular (LV) dyssynchrony, as assessed with phase analysis from gated myocardial perfusion SPECT (GMPS), can predict which patients will respond to CRT. Methods: Forty-two patients with severe heart failure, depressed LV ejection fraction, and wide QRS complex were prospectively included for implantation of a CRT device and underwent GMPS and 2-dimensional echocardiography as part of the clinical protocol. Clinical status was evaluated using the New York Heart Association (NYHA) classification, 6-min walk test, and quality-of-life score. The histogram bandwidth and phase SD (parameters indicating LV dyssynchrony) were assessed from GMPS, and the clinical status and echocardiographic variables were reassessed at 6-mo follow-up. Results: Responders (71%) and nonresponders (29%) had comparable baseline characteristics, except for histogram bandwidth (175° ± 63° vs. 117° ± 51° [P < 0.01]) and phase SD (56.3° ± 19.9° vs. 37°.1 ± 14.4° [P < 0.01]), which were significantly larger in responders compared with nonresponders. Moreover, receiver-operating-characteristic curve analysis demonstrated an optimal cutoff value of 135° for histogram bandwidth (sensitivity and specificity of 70%) and of 43° for phase SD (sensitivity and specificity of 74%) for the prediction of response to CRT. Conclusion: Response to CRT is related to the presence of LV dyssynchrony assessed by phase analysis with GMPS. A cutoff value of 135° for histogram bandwidth and of 43° for phase SD could be used to predict response to CRT. Larger prospective studies are warranted to confirm the present findings.