Left ventricular ejection fraction overcrossing 35% after one year of cardiac resynchronization therapy predicts long term survival and freedom from sudden cardiac death: single center observational experience

Background Reverse remodeling and increased LVEF after CRT correlate with survival and heart failure hospitalizations, but their relationship with the risk of SCD is unclear. We aimed to evaluate whether exceeding a threshold value of 35% for left ventricular ejection fraction (LVEF) 1 year after cardiac resynchronization therapy (CRT) predicts survival and freedom from sudden cardiac death (SCD). Methods 330 patients who survived ≥ 6 months after CRT (males 80%, age 62 ± 11 years) were grouped according to 1-year LVEF ≤ 35% (Group 1, n = 187, 57%) or > 35% (Group 2, n = 143, 43%). According to changes vs. baseline (reduction of left end-systolic volume [LVESV] ≥ 10% or increase of LVEF% > 10 units), patients were also classified as echocardiographic (Echo) non-responders (Group A, n = 152, 46%) or responders (Group B, n = 178, 54%). Results At baseline, LVESV volume was larger and LVEF was lower in Group 1 vs. Group 2 (p 35% was associated with freedom from SCD/VF. Conclusions LVEF > 35% after 1 year of CRT characterizes a favorable long-term outcome, with a very low risk for SCD

Determinants of worse prognosis in patients with cardiac resynchronization therapy defibrillators. Are ventricular arrhythmias an adjunctive risk factor?

Cardiac resynchronization therapy (CRT) is indicated in patients with systolic heart failure (HF), severe left ventricle (LV) dysfunction and interventricular dyssynchrony.In prospective observational research, we aimed to evaluate whether CRT-induced LV reverse remodelling and occurrence of ventricular arrhythmias (VT/VF) independently contribute to prognosis in patients with CRT defibrillators (CRT-D)

The Interplay of PR Interval and AV Pacing Delays Used for Cardiac Resynchronization Therapy in Heart Failure Patients: Association with Clinical Response in a Retrospective Analysis of a Large Observational Study

Background. Cardiac resynchronization therapy (CRT) is a treatment for heart failure (HF) patients with prolonged QRS and impaired left ventricular (LV) systolic function. We aim to evaluate how the baseline PR interval is associated with outcomes (all-cause death or HF hospitalizations) and LV reverse remodeling (>15% relative reduction in LV end-systolic volume). Methods. Among 2224 patients with CRT defibrillators, 1718 (77.2%) had a device programmed at out-of-the-box settings (sensed AV delay: 100 ms and paced AV delay: 130 ms). Results. In this cohort of 1718 patients (78.7% men, mean age 66 years, 71.6% in NYHA class III/IV, LVEF = 27 +/- 6%), echocardiographic assessment at 6-month follow-up showed that LV reverse remodeling was not constant as a function of the PR interval; in detail, it occurred in 56.4% of all patients but was more frequent (76.6%) in patients with a PR interval of 160 ms. In a median follow-up of 20 months, the endpoint of death or HF hospitalizations occurred in 304/1718 (17.7%) patients; in the multivariable regression analysis it was significantly less frequent when the PR interval was between 150 and 170 ms (hazard ratio = 0.79, 95% confidence interval (CI): 0.63-0.99, p = 0.046). The same PR range was associated with higher probability of CRT response (odds ratio = 2.51, 95% CI: 1.41-4.47, p = 0.002). Conclusions. In a large population of CRT patients, with fixed AV pacing delays, specific PR intervals are associated with significant benefits in terms of LV reverse remodeling and lower morbidity. These observational data suggest the importance of optimizing pacing programming as a function of the PR interval to maximize CRT response and patient outcome

Impact of mitral regurgitation on the outcome of patients treated with CRT-D: data from the InSync ICD Italian Registry.

Background: We assessed the influence of clinically significant mitral regurgitation (MR) on clinical-echocardiographic response and outcome in heart failure (HF) patients treated with a biventricular defibrillator (cardiac resynchronization therapy defibrillator [CRT-D]). Methods and Results: A total of 659 HF patients underwent successful implantation of CRT-D and were enrolled in a multicenter prospective registry (median follow-up of 15 months). Following baseline echocardiographic evaluation, patients were stratified into two groups according to the severity of MR: 232 patients with more than mild MR (Group MR+: grade 2, 3, and 4 MR) versus 427 patients with mild (grade 1) or no functional MR (Group MR−). On 6- and 12-month echocardiographic evaluation, MR was seen to have improved in the vast majority of MR+ patients, while it remained unchanged in most MR− patients. On 12-month follow-up evaluation, a comparable response to CRT was observed in the two groups, in terms of the extent of left ventricular reverse remodeling and combined clinical and echocardiographic response. During long-term follow-up, event-free survival did not differ between MR+ and MR− patients, even when subpopulations of patients with ischemic heart disease and with dilated cardiomyopathy were analyzed separately. On multivariate analysis, the only independent predictor of death from any cause was the lack of β-blocker use. Conclusions: This observational analysis supports the use of CRT-D in HF patients with clinically significant MR; MR had no major influence on patient outcom