Abstract 1867: Real-Time Three-Dimensional Echocardiographic Left Ventricular Mass to Volume Ratio Is Superior To Volumetric Indices For Arrhythmic Risk Prediction
Background: Left ventricular (LV) mass is an important prognostic factor for predicting cardiac morbidity and mortality. LV mass to volume ratio (M/V) by CMR has been shown to relate to adverse outcomes in several settings. However, the relevance of this M/V has not been established for post-MI arrhythmias. We evaluated the use of 3D echo (3D) LV M/V in predicting event free survival in post-MI patients meeting the MADIT II criteria, and compared it to EDV and ESV indexed to the body surface area (EDVi, ESVi).
Methods: Forty patients (35 males, mean age 69.6y) meeting the MADIT II criteria for implantable defibrillator (ICD) placement with an EF of ≤30% were imaged and followed up for a mean of 472 days for adverse events (ventricular fibrillation or sustained ventricular tachycardia, and appropriate ICD discharges). Patients had 3D within 24 hours of ICD implantation. EDVi, ESVi and LV mass were determined and M/V calculated. Receiver operator curves (ROC) were used to determine the associations between M/V, EDVi, ESVi and adverse events.
Results: Mean indexed LV mass was 109.7 g. Mean EDVi, ESVi were 123.3 ml/m2 and 93.4ml/m2. The adverse event rate was 25% (10/40 patients). ROC curve analysis showed that M/V was significantly associated with adverse events(p = 0.002) while EDVi (p=0.12) and ESVi (p=0.08) were not. Patients with higher M/V were more likely to have events than those with smaller M/V (area under the curve = 0.74, sensitivity 80%, specificity 67%).
3D derived LV M/V is useful for determining risk of adverse events in high-risk post-MI patients who meet the MADIT II criteria.
M/V is superior to 3D EDV, ESV for prediction of arrhythmic events this high risk population.