Quantification of ventricular resynchronization reserve by radionuclide phase analysis in XXXX @entity1 : a prospective long-term study.

@entity1 @entity712 @entity1472 @entity22286 @entity204
BACKGROUND: Phase analysis, developed to assess dyssynchrony from ECG-gated radionuclide ventriculography, has shown promising results. We hypothesized that quantifying the cardiac resynchronization reserve, that is, the extent of response to cardiac resynchronization therapy (CRT), by radionuclide imaging could potentially identify @entity1 who are best suited for CRT. METHODS AND RESULTS: Seventy-four @entity1 ages 64.8  10.1 years were prospectively studied from July 2004 to July 2006, of whom 62.2% and 37.8%, respectively, were in New York Heart Association class 3 and 4. Mean QRS width was 173  25 ms. ECG-gated radionuclide ventriculography to quantify interventricular and intraventricular dyssynchrony was performed at baseline with and without CRT and at the 3-month follow-up visit. @entity1472 -terminal-pro-brain natriuretic peptide (NT-pro-BNP) levels were also determined at baseline and at 3 months. During a mean follow-up of 10.1  7.6 months, there were 37 (50%) clinical events that defined the nonresponder group, including @entity204 or readmission for worsening @entity712 . In multivariate Cox model analysis, higher NT-pro-BNP blood levels were associated with a significant increase in the risk for event (hazard ratio=1.085 for a 100 pg/L increase in NT-pro-BNP; 95% confidence interval, 1.014 to 1.161). Each 10   elevation in intraventricular dyssynchrony was associated with a decrease in the risk of events (hazard ratio=0.456, 95% confidence interval, 0.304 to 0.683). Receiver operating characteristic curve analysis demonstrated that an @entity22286 cutoff value of 25.5   for intraventricular synchrony yielded 91.4% sensitivity and 84.4% specificity for predicting a good response to CRT. CONCLUSIONS: The quantification of @entity22286 with radionuclide phase analysis suggests that early postimplantation @entity22286 may provide identification of CRT responders.
