Abstract 12138: Prognostic Utility of 99mTc-sestamibi Gated Myocardial Scintigraphy in Predicting Response to Cardiac Resynchronization Therapy
Background: Predicting response to cardiac resynchronization therapy (CRT) remains questionable. The presence of left ventricular (LV) dyssynchrony is the most important factor that predicts response. A novel program, ‘cardioGRAF’ for analyzing 99mTc-sestamibi (MIBI) gated myocardial scintigraphic (SPECT) images can assess LV ejection fraction and LV systolic dyssynchrony from the variation in time to end-systole among 17 LV segments. The aim of this study was to evaluate the usefulness of MIBI imaging for identifying CRT responders.
Methods: We retrospectively studied 38 patients who underwent MIBI-SPECT before receiving CRT for advanced heart failure. Patients were divided to two groups: responders (R) and nonresponders (NR). Responders were defined as those with LVEDV reduction greater than 10% following CRT. SPECT findings were analyzed to obtain standard deviation of the time to end-systole among 12 (basal and mid) LV segments (SD12). Multivariable logistic regression analysis was used to identify variables associated with responders.
Results: During a postoperative follow-up period of 22.9 ± 18.2 months, 21 responders (55%) were identified. SD12 was significantly higher in responders than in nonresponders (R: 128.7±77.9, NR: 45.5±60.7, p<0.01). After multivariable adjustment, SD12 remained a significant predictor of responders (OR 1.025; 95% Cl 1.007-1.044, p<0.05). Other variables including age, gender, heart diseases, QRS duration and medication (beta-blocker, ACE-I/ARB, diuretic, amiodarone) were not associated with CRT response. In responders, SD12 decreased significantly after CRT (from 128.7±77.9 to 69.6±50.5, p<0.01).
Conclusion: MIBI imaging is a useful modality for predicting CRT response, and should be a factor to be considered in deciding CRT.
- © 2012 by American Heart Association, Inc.