Abstract 2931: Echocardiographic Changes After Cardiac Resynchronization Therapy Are Not Associated With Changes in Clinical Measures
Background: In patients with heart failure, cardiac resynchronization therapy (CRT) improves clinical measures, such as NYHA class, quality of life (QOL), and VO2, and echo measures, such as left ventricular (LV) end-systolic volume (LVESV), LV end-diastolic volume (LVEDV), and LV ejection fraction (LVEF). However, the relationship between changes in these clinical and echo measures has not been well-established. Our objective was to determine whether changes in clinical and echo measures are associated after 6 months of CRT.
Methods: The DECREASE-HF trial randomized 306 adults (NYHA III/IV HF, LVEF ≤ 35%, QRS ≥ 150 ms) to LV CRT, simultaneous biventricular CRT, or sequential biventricular CRT. LVESV, LVEDV, and LVEF were calculated using Simpson’s rule at a core lab. 6-month echo and clinical data, available for 218 patients, were pooled from all 3 pacing arms. Clinical improvement was defined as: peak VO2, ≥ 1 ml/kg/min increase; NYHA class, ≥ 1 decrease; and/or QOL, ≥ 10 units decrease in the Minnesota Living with heart failure score. Echo improvement was defined as: LVEF ≥ 5 unit increase; LVESV ≥ 15% decrease; and/or LVEDV ≥ 15% decrease. P-values were calculated by t-test and Chi-squared test.
Results: Echo changes were not significantly different among patients with clinical improvement and patients without clinical improvement, whether each clinical measure was examined individually, or grouped together. The table⇓ shows that there were no significant echo differences among patients with improvement in at least one clinical measure compared to those with no improvement in any of the clinical measures.
Conclusion: There was no association between the echo changes in LV volumes or LVEF with the clinical changes in NYHA class, QOL, or peak VO2 after CRT. Since the majority of patients did have clinical improvement, a larger study is needed confirm these findings. Further investigation is needed to determine which measures best predict long-term outcome.