Abstract 3580: Pre-Implantation Dyskinesis is an Independent Predictor of Non-Response to Cardiac Resynchronization Therapy Among Ischemic Patients
BACKGROUND: Cardiac resynchronization therapy (CRT) is an effective treatment for advanced heart failure. Despite the identification of several predictors of CRT response (QRS width reduction and intraventricular dyssynchrony), up to thirty percent of patients remain non-responders. Recently, the presence of scar in the posterolateral wall has been identified as a predictor of non-response in patients with ischemic cardiomyopathy. The purpose of this study was to define the relationship between pre-implantation dyskinesis and CRT response.
METHODS: We analyzed data from 83 patients with ischemic cardiomyopathy (69±10 years; 88% male) undergoing CRT. All patients had class III-IV NYHA symptoms despite maximal medical therapy, left ventricular ejection fraction (LVEF)≤35% and QRS>130 ms. Patients presenting with recent acute coronary events (<3months) and pre-implantation septal dyskinesis were excluded. All patients underwent a pre-implantation assessment of dyskinesis utilizing transthoracic echocardiography (TTE). Criteria used to define CRT response in patients who survived at 6 months of follow-up were:
no hospitalization for heart failure and
improvement of one or more grades in the NYHA classification. Univariate and multivariate analyses were performed.
RESULTS: CRT responders (n=39) and non-responders (n=44) presented with similar LVEF (23±7% vs. 23±8%, NS), QRS width (166±35ms vs. 162±32 ms, NS), had comparable medical treatment (ACE inhibitors, beta-blockers, diuretics and digoxin), degree of mitral regurgitation and percent right ventricular pacing. At 6 months of follow-up, 5 patients suffered cardiac death and 15 patients were admitted for heart failure hospitalization. Univariate analysis demonstrated a higher QRS reduction (−12±36ms vs. 8±33ms, p30.02) and a lower prevalence of pre-implantation dyskinesis (18% vs. 43%, p=0.01) among CRT responders. Multivariate analysis revealed two independent predictors of CRT response:
reduction in QRS duration (p=0.03) and
absence of pre-implantation dyskinesis (p= 0.02).
CONCLUSIONS: The presence of pre-implantation segmental dyskinesis is an independent predictor of CRT non-response in patients with ischemic cardiomyopathy.