Abstract 2111: Independent Prognostic Value of Ventricular Gradient for Risk Stratification of Post-Myocardial Infarction Patients: a Prospective Study
BACKGROUND: Ventricular gradient (VG) quantifies the angle between the ventricular depolarization and repolarization vectors, representing repolarization heterogeneity and potentially arrhythmic risk.
METHODS: We prospectively assessed the predictive value of VG in myocardial infarction (MI) patients analyzing 24-hour digital Holter recordings (SEER MC, GE Marquette) in 151 MI patients (age 63±12.7, 107 men). A 10-sec 12-lead ECG was recorded every 10 sec in each patient. VG was automatically computed for each ECG and the median (mVG) was used for each patient. The endpoint was cardiac death or sustained ventricular tachycardia at the 1-year follow-up.
RESULTS: The average mVG in patients who met the endpoint (10.3%) was 124.8° vs. 84.6° in those who did not (p=0.001). The area under the ROC curve was 0.747 (95% CI: 0.612–0.882). The best combination of sensitivity and specificity (80% and 66.2%) was obtained for mVG 109o. The odds ratio for the two strata (above and below this cut-off) was 7.81 (95% CI: 2.1–29.2) and the negative predictive value 96.6% (See Fig⇓.). In Cox regression entering age, sex, heart rate on admission, ejection fraction, reperfusion treatment, β-blocker use, SDNN, QTc and QRS duration, mVG remained significant (p=0.019), implying an independent predictive value. A 10o-increase of mVG conferred a 20% elevation in hazard.
CONCLUSION: This study prospectively demonstrates the prognostic value of VG from Holter recordings in MI patients. A positive test designates relatively high probability of experiencing death or life-threatening arrhythmia in the first year, while a negative result predicts, with exceptionally high certainty, a favorable outcome.