ECG marker of adverse electrical remodeling post-myocardial infarction predicts outcomes in MADIT II study
Embargo until
Date
2012-12-14
Journal Title
Journal ISSN
Volume Title
Publisher
PLoS Organization
Abstract
Background
Post-myocardial infarction (MI) structural remodeling is characterized by left ventricular dilatation, fibrosis, and hypertrophy of the non-infarcted myocardium.
Objective
The goal of our study was to quantify post-MI electrical remodeling by measuring the sum absolute QRST integral (SAI QRST). We hypothesized that adverse electrical remodeling predicts outcomes in MADIT II study participants.
Methods
Baseline orthogonal ECGs of 750 MADIT II study participants (448 [59.7%] ICD arm) were analyzed. SAI QRST was measured as the arithmetic sum of absolute QRST integrals over all three orthogonal ECG leads. The primary endpoint was defined as sudden cardiac death (SCD) or sustained ventricular tachycardia (VT)/ventricular fibrillation (VF) with appropriate ICD therapies. All-cause mortality served as a secondary endpoint.
Results
Adverse electrical remodeling in post-MI patients was characterized by wide QRS, increased magnitudes of spatial QRS and T vectors, J-point deviation, and QTc prolongation. In multivariable Cox regression analysis after adjustment for age, QRS duration, atrial fibrillation, New York Heart Association heart failure class and blood urea nitrogen, SAI QRST predicted SCD/VT/VF (HR 1.33 per 100 mV*ms (95%CI 1.11–1.59); P=0.002), and all-cause death (HR 1.27 per 100 mV*ms (95%CI 1.03–1.55), P=0.022) in both arms. No interaction with therapy arm and bundle branch block (BBB) status was found.
Conclusions
In MADIT II patients, increased SAI QRST is associated with increased risk of sustained VT/VF with appropriate ICD therapies and all-cause death in both ICD and in conventional medical therapy arms, and in patients with and without BBB. Further studies of SAI QRST are warranted.
Description
PMC3522579
Keywords
Tachycardia, Ventricular, Myocardial Infarction, Electrocardiography, Ventricular Fibrillation, Ventricular Remodeling
Citation
doi: 10.1371/journal.pone.0051812