Prevalence of true left bundle branch block in current practice of cardiac resynchronization therapy implantation

AIMS: Accurate selection of patients with left bundle branch block (LBBB) may help increasing response to cardiac resynchronization therapy (CRT). There is no agreement on LBBB definition. The aim of the study was to investigate the prevalence of 'true-LBBB' according to Strauss in patients undergoing CRT. METHODS AND RESULTS: The study population included 414 consecutive patients (71.9% men; mean age 69.7\u200a\ub1\u200a9.6 years), who underwent CRT according to 2010 European Society of Cardiology (ESC) guidelines. Patients were classified into three groups: traditional LBBB according to American Heart Association, LBBB according to Strauss and intraventricular conduction delay (IVCD). Subsequently, they were re-classified into classes of recommendations, according to the current 2013 ESC Guidelines. Traditional LBBB was recorded in 229 patients (55%), an LBBB according to Strauss in 153 (37%) and an IVCD in 32 (8%). Patients with an LBBB according to Strauss showed a significantly more prolonged QRS duration (P\u200a<\u200a0.001), greater baseline end-systolic and end-diastolic volumes (P\u200a=\u200a0.011 and P\u200a=\u200a0.013, respectively) compared with those with IVCD. The prevalence of mid-QRS notching in at least two contiguous leads was 100% in LBBB according to Strauss; 24% in traditional LBBB and 21.9% in IVCD (P\u200a<\u200a0.001). At multivariate analysis, PR interval less than 200\u200ams and QRS of at least 150\u200ams were independent predictors of mid-QRS notching [odds ratio (OR) 1.78; 95% confidence interval (95% CI) 1.10-2.88; P\u200a=\u200a0.02 and OR 2.88; 95% CI 1.80-4.62;P\u200a<\u200a0.0001]. Applying stricter criteria for LBBB according to Strauss, a significant reduction in Class I recommendation and an increase in Class II was observed (90.1 vs. 37%; P\u200a<\u200a0.0001 and 9.9 vs. 63%; P\u200a<\u200a0.0001). CONCLUSIONS: Applying stricter criteria, only 37% of patients undergoing CRT showed a true-LBBB according to Strauss. Accurate identification of true-LBBB may have a potential additional value in better selecting patients

ANMCO position paper: guide to the appropriate use of the wearable cardioverter defibrillator in clinical practice for patients at high transient risk of sudden cardiac death

Extended risk stratification and optimal management of patients with a permanently increased risk of sudden cardiac death (SCD) are becoming increasingly important. There are several clinical conditions where the risk of arrhythmic death is present albeit only transient. As an example, patients with depressed left ventricular function have a high risk of SCD that may be only transient if there will be a significant recovery of function. It is important to protect the patients while receiving and titrating to the optimal dose the recommended drugs that may lead to an improved left ventricular function. In several other conditions, a transient risk of SCD can be observed even if the left ventricular function is not compromised. Examples are patients with acute myocarditis, during the diagnostic work-up of some arrhythmic conditions or after extraction of infected catheters while eradicating the associated infection. In all these conditions, it is important to offer a protection to these patients. The wearable cardioverter defibrillator (WCD) is of particular importance as a temporary non-invasive technology for both arrhythmia monitoring and therapy in patients with increased risk of SCD. Previous studies have shown the WCD to be an effective and safe therapy for the prevention of SCD caused by ventricular tachycardia/fibrillation. The aim of this ANMCO position paper is to provide a recommendation for clinical utilization of the WCD in Italy, based upon current data and international guidelines. In this document, we will review the WCD functionality, indications, clinical evidence, and guideline recommendations. Finally, a recommendation for the utilization of the WCD in routine clinical practice will be presented, in order to provide physicians with a practical guidance for SCD risk stratification in patients who may benefit from this device

Interlead anatomic and electrical distance predict outcome in CRT patients

Background The implantation strategy appears to play a pivotal role in determining response to cardiac resynchronization therapy (CRT). Objective The aim of our study was to determine the association between anatomic and electrical interlead distance and clinical outcome after CRT implantation. Methods We included 216 first-time CRT recipients with left bundle branch block and sinus rhythm. On implantation, the electrical interlead distance (EID), defined as the time interval between spontaneous peak R waves detected at the right ventricular (RV) and left ventricular (LV) pacing sites, was measured. The anatomic distance between the RV and LV lead tips was determined on chest radiographs. Results The mean EID was 74 ± 41 ms, and the mean horizontal corrected interlead distance (HCID) was 125 ± 73 mm. After 12 months, 87 patients (40%) displayed an improvement in their clinical composite score. The cutoff values that best predicted an improved clinical status were as follows: 84 ms for EID (area under the curve 0.59; confidence interval [CI] 0.52-0.66; P =.026) and 90 mm for HCID (area under the curve 0.62; CI 0.55-0.69; P =.004). On multivariate analysis, only EID >84 ms (hazard ratio 0.36; CI 0.14-0.89; P =.028) and HCID >90 mm (hazard ratio 0.45; CI 0.23-0.90; P =.025) were significantly associated with the composite endpoint of death or cardiovascular hospitalization. In particular, the presence of both conditions (EID <84 ms and HCID <90 mm) was associated with the highest rate of events (log-rank test P =.002). Conclusions The interlead anatomic and electrical distance are strongly and independently associated with patient outcome after CRT implantation. The 2 measures show an additive predictive value. (CRT MORE: Cardiac Resynchronization Therapy Modular Registry; www.clinicaltrials.gov, unique identifier: NCT01573091.) © 2015 Heart Rhythm Society

Adherence to 2016 European Society of Cardiology guidelines predicts outcome in a large real-world population of heart failure patients requiring cardiac resynchronization therapy

Background Professional guidelines are based on the best available evidence. However, patients treated in clinical practice may differ from those included in reference trials. Objective The aim of this study was to evaluate the effects of cardiac resynchronization therapy (CRT) in a large population of patients implanted with a CRT device stratified in accordance with the 2016 European heart failure (HF) guidelines. Methods We collected data on 930 consecutive patients from the Cardiac Resynchronization Therapy MOdular REgistry. The primary end point was a composite of death and HF hospitalization. Results Five hundred sixty-three (60.5%) patients met class I indications, 145 (15.6%) class IIa, 108 (11.6%) class IIb, and 114 (12.3%) class III. After a median follow-up of 1001 days, 120 (14.7%) patients who had an indication to CRT had died and 71 (8.7%) had been hospitalized for HF. The time to the end point was longer in patients with a class I indication (hazard ratio 0.55; 95% confidence interval 0.39–0.76; P = .0001). After 12 months, left ventricular (LV) end-systolic volume had decreased by ≥15% in 61.5% (320/520) of patients whereas in 57.5% (389/676) of patients the absolute LV ejection fraction improvement was ≥5%. Adherence to class I was also associated with an absolute LV ejection fraction increase of >5% (P = .0142) and an LV end-systolic volume decrease of ≥15% (P = .0055). Conclusion In our population, ∼60% of patients underwent implantation according to the 2016 European HF guidelines class I indication. Adherence to class I was associated with a lower death and HF hospitalization rates and better LV reverse remodeling

Magnitude of QRS duration reduction after biventricular pacing identifies responders to cardiac resynchronization therapy

Background Several studies have investigated the association between native QRS duration (QRSd) or QRS narrowing and response to biventricular pacing. However, their results have been conflicting. The aim of our study was to determine the association between the relative change in QRS narrowing index (QI) and clinical outcome and prognosis in patients who undergo cardiac resynchronization therapy (CRT) implantation. Methods and results We included 311 patients in whom a CRT device was implanted in accordance with current guidelines for CRT. On implantation, the native QRS, the QRSd and the QI during CRT were measured. After 6&nbsp;months, 220 (71%) patients showed a 10% reduction in LVESV. The median [25th–75th] QI was 14.3% [7.2–21.4] and was significantly related to reverse remodeling (r&nbsp;=&nbsp;+&nbsp;0.22; 95%CI: 0.11–0.32, p&nbsp;=&nbsp;0.0001). The cut-off value of QI that best predicted LV reverse remodeling after 6&nbsp;months of CRT was 12.5% (sensitivity&nbsp;=&nbsp;63.6%, specificity&nbsp;=&nbsp;57.1%, area under the curve&nbsp;=&nbsp;0.633, p&nbsp;=&nbsp;0.0002). The time to the event death or cardiovascular hospitalization was significantly longer among patients with QI&nbsp;&gt;&nbsp;12.5% (log-rank test, p&nbsp;=&nbsp;0.0155), with a hazard ratio (HR) of 0.3 [95%CI: 0.11–0.78]. In the multivariate regression model adjusted for baseline parameters, a 10% increment in QI (HR&nbsp;=&nbsp;0.61[0.44–0.83], p&nbsp;=&nbsp;0.002) remained significantly associated with CRT response. Conclusions Patients with a larger decrease in QRSd after CRT initiation showed greater echocardiographic reverse remodeling and better outcome from death or cardiovascular hospitalization. QI is an easy-to-measure variable that could be used to predict CRT response at the time of pacing site selection or pacing configuration programming

Clinical Presentation and Outcome in a Contemporary Cohort of Patients with Acute Myocarditis: The Multicenter Lombardy Registry

Background -There is controversy regarding outcome of patients with acute myocarditis (AM), and lack of data on how patients admitted with suspected AM are managed. We report characteristics, in-hospital management and long-term outcome of patients with AM based on a retrospective multi-center registry from 19 Italian hospitals. Methods -A total of 684 patients with suspected AM and recent onset of symptoms (70 years and those older than 50 years without coronary angiography were excluded. The final study population comprised 443 patients (median age 34 years, 19.4% female) with AM diagnosed either by endomyocardial biopsy (EMB) or increased troponin plus edema and late gadolinium enhancement at cardiac magnetic resonance (CMR). Results -At presentation, 118 patients (26.6%) had either left ventricular (LV) ejection fraction (EF) <50%, sustained ventricular arrhythmias (VA) or a low cardiac output syndrome (LCOS) whilst 325 (73.4%) had no such complications. EMB was performed in 56/443 (12.6%), and a baseline CMR was performed in 415/443 (93.7%) of patients. Cardiac mortality plus heart transplant (HTx) at 1 and 5 years were 3.0% and 4.1%. Cardiac mortality plus HTx were 11.3% and 14.7% in patients with complicated presentation and 0% in uncomplicated cases (Log-rank p<0.0001). Major AM-related cardiac events after the acute phase (post-discharge death and HTx, sustained VA treated with electrical shock or ablation, symptomatic heart failure needing device implantation) occurred in 2.8% at 5-year follow up, with a higher incidence in patients with complicated forms (10.8% vs. 0% in uncomplicated AM, Log-rank p<0.0001). Beta adrenoceptor blockers were the most frequently employed medications both in complicated (61.9%) and in uncomplicated forms (53.8%, p=0.18). After a median time of 196 days, 200 patients had follow-up CMR and 8/55 (14.5%) with complications at presentation had LVEF<50% compared with 1/145 (0.7%) of those with uncomplicated presentation. Conclusions -In this contemporary study, overall serious adverse events after AM were lower than previously reported. However, patients with LVEF<50%, VA or LCOS at presentation were at higher risk compared with uncomplicated cases that had a benign prognosis and low risk of subsequent LV systolic dysfunction