Abstract 12549: Acute Reduction in Post-systolic Shortening is Related to Long-Term Outcome After Cardiac Resynchronization Therapy

Abstract

Background: Post-systolic shortening (PSS) by tissue Doppler imaging is often detected in heart failure patients. However, the meaning of changes in PSS acute after cardiac resynchronization therapy (CRT) and its association with outcome is unknown.

Objective: To test the hypothesis that acute reduction in PSS is associated wtih long-term outcome after CRT.

Methods: We studied 102 CRT patients, aged 65±11 yrs with NYHA III-IV heart failure, ejection fraction (EF) 24±6% (all ≤35%), and QRS duration 156±22 ms (all ≥120ms): 58 (57%) had ischemic disease. PSS was defined 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 3 standard apical views. Maximum ΔT was evaluated before and 24 hours after CRT. Long-term outcome was predefined as freedom from death, heart transplantation, or left ventricular assist device (LVAD) implantation over 3 years.

Results: There were 29 events: 20 deaths, 6 transplantations, and 3 LVADs. PSS-ΔT at baseline was similar in ischemic and non-ischemic patients (118±45 vs 107±40 ms). ΔT was unaltered from 113±45 to 112±61 ms (p=NS) when considering all patients. However, patients with favorable outcome had a reduction in ΔT from 112±45 to 103±41 ms (p=0.01). In contrast, patients with serious unfavorable events had no reduction in PSS ΔT from 111±38 to 133±92 ms (p=NS). Interestingly, patients with persistent PSS-ΔT ≥100 ms acute after CRT (optimal cutoff for outcome by ROC curve analysis) had a significantly less favorable outcome than patients who improved PSS-ΔT after CRT (p=0.007, Figure).

Conclusion: Reduction of PSS-ΔT by tissue Doppler appears to be a marker associated with favorable long-term outcome after CRT. This observation has clinical prognostic utility.