Abstract 19474: Patient Selection for Resynchronization Therapy: Pump Function Assessment by Pressure-Volume Loops
Purpose: Given the fact that non-response to CRT remains considerably high (∼30–50%;), invasive assessment of left ventricular (LV) pump function improvement is suggested to determine individual acute hemodynamic response to CRT. However, is remains unclear whether an increase in workload (stroke work) or increase in dP/dtmax is related to long-term response to CRT.
Methods: Thirty patients scheduled for CRT (age 65±10, 21 male) were prospectively included in the present study. Acute LV pump function improvement during biventricular pacing was assessed by pressure-volume loop measurements before implantation. Long-term response to CRT was defined by a reduction of ≥10% in LV end-systolic volume at 6 months.
Results: Baseline patient characteristics were NYHA class 3.0±0.4, EF 28±8%, QRS 151±27ms. Mean SW and dP/dtmax at baseline were respectively 5.8±3.5 ml<zmd>mmHg and 867±267 mmHg/s and increased acutely with +42±39% and +13±19%. The acute increase in SW was significantly higher in long-term responders (n=22, 73%) vs. non-responders (+57%±32% vs. +3%±28%, p<0.001), whereas non-significant differences were found in acute increase in dP/dtmax in responders vs. non-responders (+16%±20% vs. 2%±13%, p=0.06). Receiver Operating Characteristic (ROC) curve analysis revealed that SW was superior to dP/dtmax and QRS duration in prediction of response to CRT (figure). An optimal cut-off value for SW of >25% was found, predicting reverse remodeling with a sensitivity of 87% and specificity of 86%.
Conclusions: Acute SW increase was significant higher in responders compared to non-responders. Acute SW increase predicted long-term response to CRT better than acute increase in dP/dtmax or QRS duration. A cut-off value for SW of >25% predicts accurately long-term response to CRT.
- © 2010 by American Heart Association, Inc.