In post-myocardial infarction patients, increased sum absolute QRST integral independently predicted sudden cardiac death or sustained ventricular tachyarrhythmias (HR 1.33 per 100 mV*ms).
Cohort (n=750)
Single-blind
Yes
Does an increased sum absolute QRST integral (SAI QRST) predict sudden cardiac death or sustained VT/VF in post-myocardial infarction patients?
Increased sum absolute QRST integral (SAI QRST) is a significant independent predictor of sudden cardiac death, sustained VT/VF, and all-cause mortality in post-MI patients, regardless of bundle branch block status.
Effect estimate: HR 1.33 (95% CI 1.11-1.59)
p-value: p=0.002
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.
Tereshchenko et al. (Fri,) conducted a cohort in Post-myocardial infarction with systolic dysfunction (n=750). Sum absolute QRST integral (SAI QRST) vs. Lower SAI QRST was evaluated on Sudden cardiac death (SCD) or sustained ventricular tachycardia (VT)/ventricular fibrillation (VF) with appropriate ICD therapies (HR 1.33, 95% CI 1.11-1.59, p=0.002). In post-myocardial infarction patients, increased sum absolute QRST integral independently predicted sudden cardiac death or sustained ventricular tachyarrhythmias (HR 1.33 per 100 mV*ms).