In-Hospital Heart Rate Turbulence and Microvolt T-Wave Alternans Abnormalities for Prediction of Early Life-Threatening Ventricular Arrhythmia after Acute Myocardial Infarction

Department of Rhythmology, Hospices Civils de Lyon, Louis Pradel Cardiovascular Hospital, Lyon, France.
Annals of Noninvasive Electrocardiology (Impact Factor: 1.13). 11/2013; 18(6). DOI: 10.1111/anec.12072
Source: PubMed


In the setting of primary prevention, most implantable cardiac defibrillators (ICD) are implanted more than 6 months after acute myocardial infarction (AMI). Abnormal heart rate turbulence (HRT) and T-wave alternans (TWA) are predictors of long-term sudden cardiac death (SCD). We intended to assess the predictive value of HRT and TWA for early post-AMI SCD and life-threatening ventricular arrhythmias (VA). Methods
One hundred ninety-nine consecutive patients with AMI were prospectively included (age 61.7 years, LV ejection fraction 45%). One hundred eighty-three patients (92%) underwent percutaneous coronary intervention. We assessed HRT using turbulence slope (TS), turbulence onset (TO), and TWA on channels 1 and 2 (TWA1 and TWA2) using the modified moving average method. Predictive performance for SCD/VA was assessed by area under the receiver operating curve characteristic (ROC-AUC). ResultsWithin 6 months after AMI, 2 patients (1%) developed life-threatening VA and 3 (1.5%) experienced SCD. TO and TWA1 had poor ROC-AUC (both 0.64) whereas TS and TWA2 failed to show any predictive performance (ROC-AUC 0.48 and 0.57, respectively). When combining TO and TWA1, ROC-AUC increased to 0.80. Importantly, when considering the subset of patients with a LV ejection fraction ≤40%, the combined variable of TO and TWA1 remained strongly predictive of a short-term event (ROC-AUC 0.86). Conclusions
Combined assessment of HRT and TWA showed a high predictive performance for SCD or life-threatening VA within 6 months after AMI. This combined Holter ECG index could be useful to identify high-risk patients who might benefit from early ICD implantation.

Download full-text


Available from: Nicolas Girerd
  • [Show abstract] [Hide abstract]
    ABSTRACT: Reducing the toll of sudden cardiac death (SCD) remains a major challenge in cardiology, as it is the leading cause of adult mortality in the industrially developed world, claiming 310,000 lives annually in the United States alone. The main contemporary noninvasive index of cardiovascular risk, left ventricular ejection fraction (LVEF), has not proved adequately reliable, as the majority of individuals who die suddenly have relatively preserved cardiac mechanical function. Monitoring of T-wave alternans (TWA), a beat-to-beat fluctuation in ST-segment or T-wave morphology, is an attractive approach to risk stratification on both scientific and clinical grounds, as this ECG phenomenon has been shown using the FDA-cleared Spectral and Modified Moving Average methods to assess risk for cardiovascular mortality including SCD in studies enrolling >12,000 individuals with depressed or preserved LVEF. The evidence supporting TWA as a therapeutic target is reviewed. Copyright © 2014 Elsevier Inc. All rights reserved.
    No preview · Article · Oct 2014 · Trends in Cardiovascular Medicine
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Exercise-based spectral T-wave alternans (TWA) has been proposed as a noninvasive tool-identifying patients at risk of sudden cardiac death (SCD) and cardiac mortality. Prior studies have indicated that ambulatory electrocardiogram (AECG)-based TWA is an important alternative platform to exercise for risk stratification of cardiac events. This study sought to review data regarding 24-hour AECG-based TWA and to discuss its potential role in risk stratification of fatal cardiac events across a series of patient risk profiles. Prospective clinical studies of the predictive value of AECG-based TWA obtained with daily activity published between January 1990 and November 2014 were retrieved. Major endpoints included composite endpoint of SCD, cardiac mortality, and severe arrhythmic events. Data were accumulated from 5 studies involving a total of 1,588 patients, including 317 positive and 1,271 negative TWA results. Compared with the negative group, positive group showed increased rates of SCD (hazard ratio [HR]: 7.49, 95% confidence interval [CI]: 2.65 to 21.15), cardiac mortality (HR: 4.75, 95% CI: 0.42 to 53.55), and composite endpoint (SCD, cardiac mortality, and severe arrhythmic events, HR: 5.94, 95% CI: 1.80 to 19.63). For the 4 studies evaluating TWA measured using the modified moving average method, the HR associated with a positive versus negative TWA result was 9.51 (95% CI: 4.99 to 18.11) for the composite endpoint. The positive group of AECG-based TWA has a nearly six-fold risk of severe outcomes compared with the negative group. Therefore, AECG-based TWA provides an accurate means of predicting fatal cardiac events.
    Full-text · Article · Dec 2014 · BMC Cardiovascular Disorders
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Microvascular obstruction (MVO) and transmural infarct size are prognostic factors after acute myocardial infarction (AMI). We assessed the value of myocardial deformation patterns using 3D speckle tracking imaging (3DSTI) in detecting myocardial and microvascular damage after AMI. One hundred patients with first ST-segment elevation MI from the REMI Study were prospectively included. Transthoracic echocardiography with 3DSTI and CMR were performed within 72 h after revascularization therapy. Global (3DG) and segmental (3DS) values of LV longitudinal (LS), circumferential and radial area strain were obtained. Late gadolinium enhancement (LGE) and MVO was quantified as transmural (>50 %) or non-transmural (CMR was 45.8 ± 9.2 % with 22.2 ± 12.7 % transmural LGE. MVO was present in 55 patients (MVO transmural extent 11.4 ± 11.8 %). In global analysis, all 3DG strain values were correlated with LVEFCMR and infarct size, with the best correlation obtained for 3DGAS (r = −0.678; p 75 %) was 3DSAS [AUC 0.867 (0.849-0.884), 78.0 % sensitivity and 81.1 % specificity for 3DSAS = −16.1 %]. Importantly, 3DSRS and 3DSAS were associated with an increase in diagnostic accuracy of both transmural LGE and MVO over 3DSLS (all increase in AUC > 0.04, all p STEMI.
    Full-text · Article · Jun 2015 · The international journal of cardiovascular imaging
Show more