Abstract 10608: Relationship of Post-Systolic Shortening to Long-Term Survival After Cardiac Resynchronization Therapy
Background: Post-systolic shortening (PSS) by tissue Doppler imaging is often detected in heart failure patients. However, the meaning of changes in PSS following cardiac resynchronization therapy (CRT) and its association with outcome is unknown.
Methods: We studied 94 NYHA Class III-IV heart failure patients (age=65±11 yrs) who underwent CRT with LV ejection fraction (EF) 25±6% (all≤35%), and QRS duration 164±28 ms (all≥120 ms): 52 (55%) had ischemic disease. PSS was evaluated as the duration time (ΔT) of the upward spike between the end-systolic ejection phase and the onset of early diastolic relaxation. PSS was measured at mid and basal segments in the apical 4 chamber, 2 chamber, and long axis views. Maximum ΔT was evaluated at baseline and 6 months after CRT. Outcome was predefined as freedom from death, heart transplantation, or left ventricular assist device (LVAD) implantation.
Results: PSS ΔT at baseline was 116±45 overall, and was similar in ischemic and non-ischemic patients (120±31 vs 111±55 ms). There were 26 events: 22 deaths, 2 transplantations, and 2 LVADs over 4 years. ΔT was unaltered from 117±45 to 111±40 ms (p=NS) when considering all patients. However, patients with favorable event-free survival had a reduction in ΔT from 116±46 to 104±42 ms (p<0.05). In contrast, patients with serious unfavorable events had no reduction in PSS ΔT from 117±44 to 131±25 ms (p=NS). ΔT 6 months after CRT (cutoff of 110ms by ROC curve analysis) predicted unfavorable outcome with a sensitivity of 84% and specificity of 65% (area under the curve=0.72, p=0.0001). Patients with persistant PSS ΔT≥110 ms at 6 months had a significantly less favorable event-free survival than patients who improved PSS ΔT after CRT (p=0.0001).
Conclusions: Reduction of PSS ΔT by tissue Doppler appears to be a marker associated with favorable long-term event-free survival after CRT. This observation supports the relationship of PSS and CRT response and has clinical prognostic utility.
- © 2011 by American Heart Association, Inc.