Quantification of Ventricular Resynchronization Reserve by Radionuclide Phase Analysis in Heart Failure Patients

Abstract

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 patients who are best suited for CRT. Methods and Results-Seventy-four patients ages 64.8Ϯ10.1 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 173Ϯ25 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. Amino-terminal-pro-brain natriuretic peptide (NT-pro-BNP) levels were also determined at baseline and at 3 months. During a mean follow-up of 10.1Ϯ7.6 months, there were 37 (50%) clinical events that defined the nonresponder group, including cardiac death or readmission for worsening heart failure. In multivariate Cox model analysis, higher NT-pro-BNP blood levels were associated with a significant increase in the risk for event (hazard ratioϭ1.085 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 ratioϭ0.456, 95% confidence interval, 0.304 to 0.683). Receiver operating characteristic curve analysis demonstrated that an interventricular dyssynchrony 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

Ventricular dyssynchrony assessed by gated myocardial perfusion SPECT using a geometrical approach: a feasibility study

“…A number of recent studies describe the long-term prognostic value of dyssynchrony analysis. In general dyssynchrony indices may provide better identification of CRT response or major cardiac events compared to other commonly used predictors such as LVEF and QRS duration [2, 3, 5, 6]. Although the present study primarily focuses on the geometrical approach, other feasible automated methods to determine ventricular dyssynchrony in MPS data have been proposed, most of which are count based.…”

“…In recent years mechanical ventricular dyssynchrony has become an important clinical parameter, as it may indicate the effectiveness of cardiac resynchronization therapy (CRT) in heart failure patients [1–5]. Additionally, several studies have demonstrated that ventricular dyssynchrony can be used as an independent predictor for adverse cardiac events [6, 7].…”

“…Despite the large base of evidence and the widespread availability of echocardiography, it is also highly user dependent. Radionuclide ventriculography has been used to study inter- and intraventricular dyssynchrony and has proven to be a reproducible and precise technique [5]. Still, this nuclear technique only provides functional information on the contractility.…”

Normality Index of Ventricular Contraction Based on a Statistical Model from FADS

“…Several studies have reported an improvement of interventricular and intraventricular dyssynchrony after CRT, using the Fourier phase analysis of ERNA images [25–29]. Dauphin et al [30] showed that interventricular dyssynchrony was identified as an independent predictive factor of good clinical response with a practical cut-off value of 25.5°, a sensitivity of 91.4%, and a specificity of 84.4%. However, Fourier phase analysis based only on one FT harmonic has its limitations, since it assumes periodic TACs and a smooth transition between the first and last frame of the dynamic images series.…”

A new perspective for phase analysis of radionuclide angiocardiography

“…In a heterogenous population study, Dauphin et al observed that an interventricular dyssynchrony cut-off value of 25.5°on RNA was a good predictor of major events defined on a composite criteria including HF progression, heart transplantation, and cardiac death. 9 Similarly, but in a population of 103 patients with only idiopathic dilated cardiomyopathy, Fauchier et al found that an increase SD of LV mean phase analysis (SD cut-off value of 50 ms) was a strong predictor of cardiac events. After multivariate analysis, SD of LV mean phase and pulmonary capillary wedge pressure were the two independent predictors of cardiac death and worsening of HF leading to heart transplantation.…”