Alessandra Denaro

A simplified biventricular defibrillator with fixed long detection intervals reduces implantable cardioverter defibrillator (ICD) interventions and heart failure hospitalizations in patients with non-ischaemic cardiomyopathy implanted for primary prevention: the RELEVANT [Role of long dEtection window programming in patients with LEft VentriculAr dysfunction, Non-ischemic eTiology in primary prevention treated with a biventricular ICD] study

Aims To investigate the efficacy and safety of a cardiac resynchronization therapy with cardioverter–defibrillator (CRT-D) device with simplified ventricular tachycardia management in patients with non-ischaemic heart failure (HF) and primary prevention implantable cardioverter defibrillator (ICD) indication. Methods and results Prospective, controlled, parallel, multicentre, non-randomized study enrolling 324 primary prevention non-ischaemic HF patients implanted with CRT-D devices from 2004 to 2007: Protect group, 164 patients implanted with a Medtronic Insync III Protect device and Control group, 160 patients utilizing other Medtronic CRT-D devices. Efficacy was assessed by computing appropriate and inappropriate detections and therapies during follow-up; safety compared hospitalizations and syncopal events between groups. Ninety per cent of both ventricular and supraventricular tachyarrhythmias terminated within the 13–29 beat detection interval with the Protect algorithm. The Protect group showed a significantly better event-free survival to first delivered therapy for total (P = 0.0001), appropriately treated (P = 0.002), and inappropriately treated episodes (P = 0.017). The total number of delivered shocks was significantly lower in the Protect group (22 vs. 59, P < 0.0001). In the Protect group, a significantly reduced HF hospitalization (hazard ratio 0.38, 95% CI 0.15–0.98, P = 0.044) was observed without any increase of syncope or death. Conclusion A simplified CRT-D device with fixed long detection reduced overall ICD therapy burden and HF hospitalizations without entailing any additional adverse events in primary prevention non-ischaemic HF patients.

Monitoring Intrathoracic Impedance with an Implantable Defibrillator Reduces Hospitalizations in Patients with Heart Failure

Purpose: Some implantable cardioverter‐defibrillators (ICDs) are now able to monitor intrathoracic impedance. The aim of the study was to describe the use of such monitoring in clinical practice and to evaluate the clinical impact of the fluid accumulation alert feature of these ICDs.

Prediction of response to cardiac resynchronization therapy: The selection of candidates for CRT (SCART) study

Background: The aim of this study was to evaluate the ability of baseline clinical and echocardiographic parameters to predict a positive response to CRT.

Persistent Atrial Fibrillation Worsens Heart Rate Variability, Activity and Heart Rate, as Shown by a Continuous Monitoring by Implantable Biventricular Pacemakers in Heart Failure Patients

Background: Atrial fibrillation (AF) induces loss of atrial contribution, heart rate irregularity, and fast ventricular rate.

Long-Term Survival in Patients Treated with Cardiac Resynchronization Therapy: A 3-Year Follow-Up Study from the InSync/InSync ICD Italian Registry

Background: Studies reporting the long‐term survival of patients treated with cardiac resynchronization therapy (CRT) outside the realm of randomized controlled trials are still lacking. The aim of this study was to quantify the survival of patients treated with CRT in clinical practice and to investigate the long‐term effects of CRT on clinical status and echocardiographic parameters.

Early and late QRS morphology and width in biventricular pacing: relationship to lead site and electrical remodeling.

Abstract48 patients (40 Male), mean age 68 ± 8 years, in III–IV class, with intraventricular conduction delay, received a biventricular pacemaker. Heart failure aetiology was non-ischemic in 60%. Left ventricular lead positioning was inferior in 5 patients (10%), posterior in 12 (25%), lateral in 18 (37%) and anterior in 13 (27%). QRS duration and axis were evaluated in sinus rhythm, and during right ventricular pacing, left ventricular pacing and biventricular pacing, the last early after implant and late after 8.8 ± 4.3 months. QRS duration (ms) was 154 ± 29 in sinus rhythm, 175 ± 28 during right ventricular pacing, 196 ± 31 during left ventricular pacing, 122 ± 23 during biventricular pacing “early” and 120 ± 18 during biventricular pacing “late.” All the differences were statistically significant, but not between “early” and “late” biventricular pacing. Mean QRS axis (°) was −27 ± 32 in sinus rhythm, −75 ± 4 during right ventricular pacing, 112 ± 41 during left ventricular pacing, −82 ± 51 during biventricular pacing “early” and −80 ± 42 during biventricular pacing “late.” Only the difference between left ventricular pacing and all the other groups was statistically significant. QRS axis did not significantly differ according to left ventricular lead site during left and biventricular pacing. “Late” compared with “early” biventricular pacing axis showed variation >30° in 35% of patients, in spite of no significant changes in QRS duration and x-ray positioning. Conclusion: Biventricular pacing significantly reduced QRS width, which persisted long-term. Left and biventricular pacing axis was poorly related to left ventricular lead positioning. Biventricular pacing axis variability over time may suggest a role of electrical remodeling.

Presence of left ventricular contractile reserve predicts midterm response to cardiac resynchronization therapy—results from the LOw dose DObutamine Stress-Echo Test in Cardiac Resynchronization Therapy (LODO-CRT) Trial

BACKGROUND Cardiac resynchronization therapy (CRT) is effective in selected patients with heart failure (HF). Nevertheless, the nonresponder rate remains high. The low-dose dobutamine stress-echo (DSE) test detects the presence of left ventricular (LV) contractile reserve (LVCR) in HF patients of any etiology and may be useful in predicting response to resynchronization. OBJECTIVE The purpose of this study was to present the results of the LODO-CRT trial, which evaluated whether LVCR presence at baseline increases the chances of response to CRT. METHODS LODO-CRT is a multicenter prospective study that enrolled CRT candidates according to guidelines. LVCR presence was defined as an LV ejection fraction increase >5 units during DSE test. CRT response is assessed at 6-month follow-up as an LV end-systolic volume reduction ≥10%. RESULTS Two hundred seventy-one patients were enrolled. The DSE test was feasible without complications in 99% of patients. Nine patients died from noncardiac disease, and 31 presented inadequate data. Two hundred thirty-one patients were included in the analysis. Mean patient age was 67 ± 10 years; 95% were in New York Heart Association class III, and 42% had HF of ischemic etiology. Mean QRS and LV ejection fraction were 147 ± 25 ms and 27% ± 6%, respectively. LVCR presence was found in 185 subjects (80%). At follow-up, 170 (74%) patients responded to CRT, 145/185 in the group with LVCR (78%) and 25/46 (54%) in the group without LVCR. Difference in responder proportion to CRT was 24% (P <.001). Reported test sensitivity is 85%. CONCLUSION The DSE test in CRT candidates is safe and feasible. LVCR presence at baseline increases the chances of response to CRT.

Electrical storm in patients with biventricular implantable cardioverter defibrillator: Incidence, predictors, and prognostic implications

BACKGROUND The aim of the present study was to evaluate the incidence, predictors, and related outcomes of patients with heart failure (HF) treated with cardiac resynchronization therapy with an implantable cardioverter defibrillator (CRT-D) who experienced electrical storm (ES). Electrical storm was defined as the occurrence of >or=3 episodes in 24 hours of sustained ventricular tachyarrhythmias. METHODS A total of 631 patients with HF (90% male, mean 66+/-9 years) consecutively received a CRT-D device. At baseline, the mean left ventricular ejection fraction was 26%+/-7%, the QRS duration was 164+/-33 milliseconds, and the mean New York Heart Association class was 3.3+/-0.3. RESULTS During a mean follow-up of 19+/-11 months, 2,419 ventricular tachyarrhythmia episodes were appropriately detected in 141 (22%) patients. Electrical storm occurred in 45 (7%) of 631 patients. Kaplan-Meier analysis and multivariable Cox regression showed that ES is more frequent in secondary prevention (hazard ratio 2.3, 95% CI 1.2-4.3, P=.015) and in nonischemic patients (hazard ratio 2.0, 95% CI 1.1-3.8, P=.028). In patients who presented ES, CRT was associated with only marginal nonsignificant improvements of New York Heart Association class and left ventricular ejection fraction. Hospitalizations and death due to HF were more frequent in patients with ES compared with those without ES, amounting to 16.8 (4.3) versus 8.6 (0.9) per 100 patient-years (P = .018) and 7.7 versus 2.7 per 100 patient-years (P=.014), respectively. CONCLUSIONS Electrical storm affect only 7% of CRT-D recipients and occurred more frequently in nonischemic patients with HF with biventricular implantable cardioverter defibrillators implanted for secondary prevention. Electrical storm was associated with worse HF morbidity and mortality.

Low-dose dobutamine test associated with interventricular dyssynchrony: a useful tool to identify cardiac resynchronization therapy responders: data from the LOw dose DObutamine stress-echo test in Cardiac Resynchronization Therapy (LODO-CRT) phase 2 study.

BACKGROUND Cardiac resynchronization therapy (CRT) is effective in patients with heart failure, but 30% to 50% of subjects are classified as nonresponders. Identifying responders remains a challenging task. AIMS The LODO-CRT trial investigated the association between left ventricular contractile reserve (LVCR) and clinical and echocardiographic long-term CRT response. METHODS This is a multicenter, prospective, observational study. Left ventricular contractile reserve was detected using a dobutamine stress echocardiography test, defined as an ejection fraction increase of >5 points. Clinical CRT response was defined as the absence of major cardiovascular events (ie, cardiovascular death or heart failure hospitalization). Echocardiographic response was defined as a left ventricle end-systolic volume reduction of >10%. RESULTS A total of 221 CRT-indicated patients were studied (80% presented LVCR). During a mean follow-up of 15 ± 5 months, 17 patients died and 16 were hospitalized due to heart failure. The proportion of clinical responders was 155 (88%) of 177 and 33 (75%) of 44 (P = .036) in the groups with and without LVCR, respectively. Kaplan-Meier analysis showed a significant difference in cardiac survival/hospitalization between patients with and without LVCR. The proportion of echocardiographic responders was 144 (87%) of 166 and 16 (42%) of 38 in the groups with and without LVCR (P < .001), respectively; LVCR showed 90% sensitivity and 87% positive predictive value to prefigure echocardiographic CRT responders. Multivariable analysis identified LVCR and interventricular dyssynchrony as independent predictors of CRT response. The concomitant presence of both factors showed 99% specificity and 83% sensitivity in detecting responders. CONCLUSION The presence of LVCR helps in predicting a clinical and echocardiographic CRT response. Concomitant assessment of LVCR and interventricular dyssynchrony accurately stratifies responder and nonresponder patients.

Clustering of ventricular tachyarrhythmias in heart failure patients implanted with a biventricular cardioverter defibrillator.

Background: Temporal patterns of ventricular tachyarrhythmia (VT/VF) have been studied only in patients who have received implantable cardioverter defibrillators (ICD) for secondary prevention of sudden death, and mainly in ischemic patients. The aim of this study was to evaluate VT/VF recurrence patterns in heart failure (HF) patients with biventricular ICD and to stratify results according to HF etiology and ICD indication.