TY - JOUR
T1 - Short-term variability of repolarization predicts ventricular tachycardia and sudden cardiac death in patients with structural heart disease
T2 - A comparison with QT variability index
AU - Oosterhoff, Peter
AU - Tereshchenko, Larisa G.
AU - Van Der Heyden, Marcel A.G.
AU - Ghanem, Raja N.
AU - Fetics, Barry J.
AU - Berger, Ronald D.
AU - Vos, Marc A.
N1 - Funding Information:
P.O. was supported by a Casimir grant from the Netherlands Organisation for Scientific Research (NWO), grant number 018.001.051 . The ICD-EGMs study (registration identification number NCT00916435 ) was partially supported by Medtronic, Inc., as an Investigator-Initiated Research Project (awarded to L.T. and R.B.). This research was performed within the framework of CTMM, the Center for Translational Molecular Medicine ( www.ctmm.nl ), project COHFAR (grant 01C-203 ), and supported by the Netherlands Heart Foundation. P.O. is an employee of Medtronic Bakken Research Center, The Netherlands. R.G. is an employee of Medtronic Inc. Minneapolis, Minnesota.
PY - 2011/10
Y1 - 2011/10
N2 - Background: Monitoring arrhythmic risk may improve management of patients with implantable cardioverter-defibrillators (ICD) and prevent ICD shocks. Changes in repolarization duration between subsequent beats quantified as short-term variability (STV) is associated with ventricular arrhythmias in several animal models. Objective: We evaluated STV of QT from right ventricular intracardiac ICD electrograms in patients with structural heart disease and compared its predictive value with the QT variability index (QTVI). Methods: In 233 patients, STV over 60 beats for QT and RR intervals and their ratio was calculated (STVQT, STVRR, STVRatio, respectively). QTVI was derived from mean and SD of QT and heart rate. Follow-up duration was 26 ± 15 months. Predictive value was determined for sudden arrhythmic death (SAD) defined as sudden cardiac death or fast ventricular tachycardia/fibrillation [CL < 240 ms]. Results: In univariate analysis, STVRatio, but not STVQT or STVRR, was predictive of SAD. Hazard ratios for highest quartile STVRatio and QTVI were comparable (STVRatio: 1.9, 95% confidence interval [CI] 1.1 to 3.3, P =.038, QTVI: 2.2, 95% CI 1.2 to 3.8, P =.010). In a multivariate model, highest quartile STVRatio was predictive of SAD after adjustment for New York Heart Association class, history of ischemia, ICD indication, and use of class I antiarrhythmics (hazard ratio 1.8, 95% CI 1.0 to 3.4, P <.050). A combined criterion of highest quartile for both STV Ratio and QTVI identified patients at highest risk (hazard ratio 2.4, 95% CI 1.3 to 4.3, P =.005, positive predictive value 38%, negative predictive value 82%). Conclusion: STVRatio from ICD electrograms is predictive of SAD. Predictive value is similar for order-based STVRatio and distribution-based QTVI, but the combination of both parameters can further improve results.
AB - Background: Monitoring arrhythmic risk may improve management of patients with implantable cardioverter-defibrillators (ICD) and prevent ICD shocks. Changes in repolarization duration between subsequent beats quantified as short-term variability (STV) is associated with ventricular arrhythmias in several animal models. Objective: We evaluated STV of QT from right ventricular intracardiac ICD electrograms in patients with structural heart disease and compared its predictive value with the QT variability index (QTVI). Methods: In 233 patients, STV over 60 beats for QT and RR intervals and their ratio was calculated (STVQT, STVRR, STVRatio, respectively). QTVI was derived from mean and SD of QT and heart rate. Follow-up duration was 26 ± 15 months. Predictive value was determined for sudden arrhythmic death (SAD) defined as sudden cardiac death or fast ventricular tachycardia/fibrillation [CL < 240 ms]. Results: In univariate analysis, STVRatio, but not STVQT or STVRR, was predictive of SAD. Hazard ratios for highest quartile STVRatio and QTVI were comparable (STVRatio: 1.9, 95% confidence interval [CI] 1.1 to 3.3, P =.038, QTVI: 2.2, 95% CI 1.2 to 3.8, P =.010). In a multivariate model, highest quartile STVRatio was predictive of SAD after adjustment for New York Heart Association class, history of ischemia, ICD indication, and use of class I antiarrhythmics (hazard ratio 1.8, 95% CI 1.0 to 3.4, P <.050). A combined criterion of highest quartile for both STV Ratio and QTVI identified patients at highest risk (hazard ratio 2.4, 95% CI 1.3 to 4.3, P =.005, positive predictive value 38%, negative predictive value 82%). Conclusion: STVRatio from ICD electrograms is predictive of SAD. Predictive value is similar for order-based STVRatio and distribution-based QTVI, but the combination of both parameters can further improve results.
KW - Arrhythmia
KW - ICD
KW - Risk stratification
KW - Structural heart disease
KW - Variability or repolarization
KW - intracardiac electrogram
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U2 - 10.1016/j.hrthm.2011.04.033
DO - 10.1016/j.hrthm.2011.04.033
M3 - Article
C2 - 21699842
AN - SCOPUS:84860390075
SN - 1547-5271
VL - 8
SP - 1584
EP - 1590
JO - Heart Rhythm
JF - Heart Rhythm
IS - 10
ER -