Myocardial Fibrosis Predicts Ventricular Arrhythmias and Sudden Death After Cardiac Electronic Device Implantation.

BACKGROUND: Increasing evidence supports a link between myocardial fibrosis (MF) and ventricular arrhythmias. OBJECTIVES: The purpose of this study was to determine whether presence of myocardial fibrosis on visual assessment (MFVA) and gray zone fibrosis (GZF) mass predicts sudden cardiac death (SCD) and ventricular fibrillation/sustained ventricular tachycardia after cardiac implantable electronic device (CIED) implantation. METHODS: In this prospective study, total fibrosis and GZF mass, quantified using cardiovascular magnetic resonance, was assessed in relation to the primary endpoint of SCD and the secondary, arrhythmic endpoint of SCD or ventricular arrhythmias after CIED implantation. RESULTS: Among 700 patients (age 68.0 ± 12.0 years), 27 (3.85%) experienced a SCD and 121 (17.3%) met the arrhythmic endpoint over median 6.93 years (IQR: 5.82-9.32 years). MFVA predicted SCD (HR: 26.3; 95% CI: 3.7-3,337; negative predictive value: 100%). In competing risk analyses, MFVA also predicted the arrhythmic endpoint (subdistribution HR: 19.9; 95% CI: 6.4-61.9; negative predictive value: 98.6%). Compared with no MFVA, a GZF mass measured with the 5SD method (GZF5SD) >17 g was associated with highest risk of SCD (HR: 44.6; 95% CI: 6.12-5,685) and the arrhythmic endpoint (subdistribution HR: 30.3; 95% CI: 9.6-95.8). Adding GZF5SD mass to MFVA led to reclassification of 39% for SCD and 50.2% for the arrhythmic endpoint. In contrast, LVEF did not predict either endpoint. CONCLUSIONS: In CIED recipients, MFVA excluded patients at risk of SCD and virtually excluded ventricular arrhythmias. Quantified GZF5SD mass added predictive value in relation to SCD and the arrhythmic endpoint.

Temporal trends in outcome and patient characteristics in dilated cardiomyopathy, data from the Swedish Heart Failure Registry 2003-2015.

BACKGROUND: Temporal trends in clinical composition and outcome in dilated cardiomyopathy (DCM) are largely unknown, despite considerable advances in heart failure management. We set out to study clinical characteristics and prognosis over time in DCM in Sweden during 2003-2015. METHODS: DCM patients (n = 7873) from the Swedish Heart Failure Registry were divided into three calendar periods of inclusion, 2003-2007 (Period 1, n = 2029), 2008-2011 (Period 2, n = 3363), 2012-2015 (Period 3, n = 2481). The primary outcome was the composite of all-cause death, transplantation and hospitalization during 1 year after inclusion into the registry. RESULTS: Over the three calendar periods patients were older (p = 0.022), the proportion of females increased (mean 22.5%, 26.4%, 27.6%, p = 0.0001), left ventricular ejection fraction was higher (p = 0.0014), and symptoms by New York Heart Association less severe (p < 0.0001). Device (implantable cardioverter defibrillator and/or cardiac resynchronization) therapy increased by 30% over time (mean 11.6%, 12.3%, 15.1%, p < 0.0001). The event rates for mortality, and hospitalization were consistently decreasing over calendar periods (p < 0.0001 for all), whereas transplantation rate was stable. More advanced physical symptoms correlated with an increased risk of a composite outcome over time (p = 0.0043). CONCLUSIONS: From 2003 until 2015, we observed declining mortality and hospitalizations in DCM, paralleled by a continuous change in both demographic profile and therapy in the DCM population in Sweden, towards a less affected phenotype.

Timely and individualized heart failure management: need for implementation into the new guidelines.

Due to remarkable improvements in heart failure (HF) management over the last 30 years, a significant reduction in mortality and hospitalization rates in HF patients with reduced ejection fraction (HFrEF) has been observed. Currently, the optimization of guideline-directed chronic HF therapy remains the mainstay to further improve outcomes for patients with HFrEF to reduce mortality and HF hospitalization. This includes established device therapies, such as implantable defibrillators and cardiac resynchronization therapies, which improved patients' symptoms and prognosis. Over the last 10 years, new HF drugs have merged targeting various pathways, such as those that simultaneously suppress the renin-angiotensin-aldosterone system and the breakdown of endogenous natriuretic peptides (e.g., sacubitril/valsartan), and those that inhibit the If channel and, thus, reduce heart rate (e.g., ivabradine). Furthermore, the treatment of patient comorbidities (e.g., iron deficiency) has shown to improve functional capacity and to reduce hospitalization rates, when added to standard therapy. More recently, other potential treatment mechanisms have been explored, such as the sodium/glucose co-transporter inhibitors, the guanylate cyclase stimulators and the cardiac myosin activators. In this review, we summarize the novel developments in HFrEF pharmacological and device therapy and discuss their implementation strategies into practice to further improve outcomes.

Cardiac Resynchronization Therapy in Patients with Heart Failure: What is New?

Cardiac resynchronization therapy (CRT) is an established treatment of patients with medically refractory, mild-to-severe systolic heart failure (HF), impaired left ventricular function, and wide QRS complex. The pathologic activation sequence observed in patients with abnormal QRS duration and morphology results in a dyssynchronous ventricular activation and contraction leading to cardiac remodeling, worsening systolic and diastolic function, and progressive HF. In this article, the authors aim to explore the current CRT literature, focusing their attentions on the promising innovation in this field.

New frontiers in cardiac devices.

This article provides an overview of current cardiac device management, complications, and future areas for development. The last 70 years have seen huge advances in the field of implantable cardiac devices, from diagnostic tools to electrical therapies for bradycardia, ventricular arrhythmia and cardiac resynchronisation. While out-of-hours specialist cardiology cover and regional arrhythmia pathways are increasingly established, they are not universal, and the management of arrhythmia remains an important facet of clinical medicine for the general physician. This article discusses core recommendations from international guidelines with respect to heart rhythm diagnostics, pacing for bradycardia, cardiac resynchronisation and implantable cardioverter defibrillators, along with common complications. Finally, future innovations such as the diagnostic potential of portable technologies, antibiotic envelopes for cardiac devices and the increasing use of leadless pacemakers are described.

Second European Society of Cardiology Cardiac Resynchronization Therapy Survey: the Italian cohort.

AIM: Adherence to guidelines was not homogeneous in Europe, according to the survey on cardiac resynchronization therapy conducted in 2008-2009. The aim of our study was to compare the results in the Italian and European cohorts of the Second European Cardiac Resynchronization Therapy Survey. METHODS: Patients' characteristics, procedural data and follow-up were collected. Italian records were compared with European countries. RESULTS: Italian hospitals enrolled 526 patients. The italian cohort was older (71.6 ±â€Š9.5 vs. 68.4 ±â€Š10.8; P < 0.00001), had less severe NYHA class (>II 47.2 vs. 59.6%; P < 0.00001), higher ejection fraction (30.3 ±â€Š7.4 vs. 28.4 ±â€Š8.2%; P < 0.00001), and less atrial fibrillation prevalence (34.4 vs. 41.2%; P = 0.00197) than the European cohort. Italian patients were more frequently hospitalized for heart failure in the previous year (51.9 vs. 46.2%; P = 0.01118) and had lower mean QRS duration (151 ±â€Š26 vs. 157 ±â€Š27 ms; P < 0.0001). CRT-D were more often implanted in Italian patients (79.3 vs. 69.3%; P < 0.00001). The complication rate was similar (4.6% vs. 5.6%; ns). The rate of use of ACEi/ARBs in Italy was lower than in Europe (77.2 vs. 86.9%; P < 0.00001). Patients were followed up in the implantation centre (92.1 vs. 86%; P = 0.00014), but rarely with remote monitoring (25.9 vs. 30%; P = 0.04792). CONCLUSION: The survey demonstrates important similarities as well as substantial differences regarding most of the aspects evaluated. Efforts to implement adherence to guidelines will be endorsed in Italy.

Withdrawal of Neurohumoral Blockade After Cardiac Resynchronization Therapy.

BACKGROUND: The necessity of neurohumoral blockers in patients with heart failure who demonstrate normalized ejection fractions after cardiac resynchronization therapy remains unclear. OBJECTIVES: The aim of this study was to investigate the feasibility and safety of neurohumoral blocker withdrawal in patients with normalized ejection fractions after cardiac resynchronization therapy. METHODS: In this prospective, open-label, randomized controlled pilot trial with a 2 × 2 factorial design, subjects were randomized to withdrawal of renin-angiotensin-aldosterone system inhibitors and/or beta-blockers versus continuation of treatment. The primary endpoint was a recurrence of negative remodeling, defined as an increase in left ventricular end-systolic volume index of >15% at 24 months. The secondary endpoint was a composite safety endpoint of all-cause mortality, heart failure-related hospitalizations, and incidence of sustained ventricular arrhythmias at 24 months. RESULTS: Eighty subjects were consecutively enrolled and randomized among 4 groups (continuation of neurohumoral blocker therapy, n = 20; withdrawal of renin-angiotensin-aldosterone system inhibitors, n = 20; withdrawal of beta-blockers, n = 20; and withdrawal of renin-angiotensin-aldosterone system inhibitors and beta-blockers, n = 20). Of the 80 subjects, 6 (7.5%) met the primary and 4 (5%) the secondary endpoint. However, re-initiation of neurohumoral blockers occurred in 17 subjects because of hypertension or supraventricular arrhythmias. CONCLUSIONS: The incidence of the primary and secondary endpoints over a follow-up period of 2 years was low in both the control group and in the groups in which neurohumoral blockers were discontinued. However, neurohumoral blocker withdrawal was hampered by cardiac comorbidities. (Systematic Withdrawal of Neurohumoral Blocker Therapy in Optimally Responding CRT Patients [STOP-CRT]; NCT02200822).

Cardiac implantable electrical devices in patients with hypertrophic cardiomyopathy: single center implant data extracted from the Swedish pacemaker and ICD registry.

Objectives: To investigate cardiac implantable electrical device (CIED) first implants in patients with hypertrophic cardiomyopathy (HCM) in a Swedish tertiary university hospital. Design: Clinical and technical data on pacemaker, implantable cardioverter defibrillator (ICD), and cardiac resynchronization therapy (CRT) first implants performed in HCM patients at the Karolinska University Hospital from 2005 to 2016 were extracted from the Swedish Pacemaker and ICD Registry. Echocardiographic data were obtained by review of hospital recordings. Results: The number of first pacemaker implants in HCM patients was 70 (1.5% of total pacemaker implants). The mean age of HCM pacemaker patients was 71 ± 10 years. Pacemaker implants were almost uniformly distributed between genders. Dual-chamber pacemakers with or without CRT properties were prevalent (6 and 93%, respectively). The number of first ICD implants in HCM patients was 99 (5.1% of total ICD implants). HCM patients receiving an ICD were 53 ± 15 years and prevalently men (70%). Sixty-five (66%) patients were implanted for primary prevention. Dual-chamber ICDs with or without CRT were 21 and 65%, respectively. Obstructive HCM was present in 47% pacemaker patients and 25% ICD patients with available pre-implant echo. Conclusions: This retrospective registry-based study provides a picture of CIED first implants in HCM patients in a Swedish tertiary university hospital. ICDs were the most commonly implanted devices, covering 59% of CIED implants. HCM patients receiving a pacemaker or an ICD had different epidemiological and clinical profiles.

High intensity interval training after cardiac resynchronization therapy: An explorative randomized controlled trial.

BACKGROUND: CRT leads to improvement in exercise capacity, cardiac function and mortality in selected CHF patients. Exercise capacity improves even greater when combining CRT with moderate-intensity exercise training (ET). However, high-intensity interval training (HIT) as additional therapy to CRT has not yet been established. Given the complementary physiological effects of HIT, we hypothesized that HIT after CRT may have additional effects on exercise capacity. METHODS: 24 CHF patients, NYHA class II/III and accepted for CRT underwent an echocardiogram, QoL questionnaire and CPET with cardiac output (CO) measurements before implantation, at 3 and 6 months. After 3 months, patients were randomized to usual care (UC) or HIT, consisting of 36 sessions at 85-95% of peak V̇O2. RESULTS: Peak V̇O2 increased after CRT (17±5.3 to 18.7±6.2 ml/kg/min, p < 0.05); after HIT there was a non-significant increase of 1.4 ml/kg/min (p = 0.12). Peak workload increased after CRT (109±45 to 118±44 W, p = 0.001). An additional significant within- and between group increase after HIT was found in the intervention group (128±42 to 148±48 W, versus 110±50 to 110±50, respectively, p = 0.03). Peak CO did not change significantly after CRT or HIT. V̇O2 recovery kinetics speeded by 27% after CRT (p = 0.04), no further improvement after HIT was observed. LVEF increased 25% after CRT (p = 0.0001), no additional increase was seen after HIT. CONCLUSION: This study demonstrates that HIT provides additional improvement of exercise capacity without a concomitant change in peak V̇O2 or CO suggesting that the additional effect of HIT is mainly mediated by an improvement of anaerobic performance.

The European Society of Cardiology Cardiac Resynchronization Therapy Survey II: A comparison of cardiac resynchronization therapy implantation practice in Europe and France.

BACKGROUND: The first European Cardiac Resynchronization Therapy (CRT) Survey, conducted in 2008-2009, showed considerable variations in guideline adherence and implantation practice. A second prospective survey (CRT Survey II) was then performed to describe contemporary clinical practice regarding CRT among 42 European countries. AIM: To compare the characteristics of French CRT recipients with the overall European population of CRT Survey II. METHODS: Demographic and procedural data from French centres recruiting all consecutive patients undergoing either de novo CRT implantation or an upgrade to a CRT system were collected and compared with data from the European population. RESULTS: A total of 11,088 patients were enrolled in CRT Survey II, 754 of whom were recruited in France. French patients were older (44.7% aged≥75 years vs 31.1% in the European group), had less severe heart failure symptoms, a higher baseline left ventricular ejection fraction and fewer co-morbidities. Additionally, French patients had a shorter intrinsic QRS duration (19.1% had a QRS<130ms vs 12.3% in the European cohort). Successful implantation rates were similar, but procedural and fluoroscopy times were shorter in France. French patients were more likely to receive a CRT pacemaker than European patients overall. Of note, antibiotic prophylaxis was reported to be administered less frequently in France, and a higher rate of early device-related infection was observed. Importantly, French patients were less likely to receive optimal drugs for treating heart failure at hospital discharge. CONCLUSION: This study highlights contemporary clinical practice in France, and describes substantial differences in patient selection, implantation procedure and outcomes compared with the other European countries participating in CRT Survey II.

Comparison of Usefulness of Cardiac Resynchronization Therapy in Patients With Type 1 Myotonic Dystrophy With Versus Without Left Bundle Branch Block.

Patients with type 1 myotonic dystrophy show reduced left ventricular systolic function in the presence of left bundle branch block due to electromechanical dys-synchrony. Our prospective study tracked a cohort of 64 type 1 myotonic dystrophy patients that demonstrated a high burden of atrial and ventricular arrhythmias and conduction delays. Of these patients, 12 (19%) patients had left bundle branch block, which was associated with reduced left ventricular systolic function. Eight of these patients received cardiac resynchronization therapy devices resulting in reduction of median QRS complex duration from 173 to 166 ms (p = 0.04), and improvement in median left ventricular ejection fraction from 37% to 46% (p = 0.007). In conclusion, cardiac resynchronization therapy device therapy is both feasible and effective in treating advanced cardiac disease in this vulnerable group of patients by improving left ventricular function.

Occurrence, mortality and predictors of complicated cardiac perforation in patients with CRT-D: Based on the National Inpatient Sample registry.

BACKGROUND: Cardiac Resynchronization Therapy Defibrillator (CRT-D) has been one of the most important therapies for patients with cardiomyopathy over the last decades. Cardiac perforation occurs infrequently but can be fatal. The occurrence of cardiac perforation after CRT-D implantation has not been studied well. The aim of study is to investigate the occurrence, mortality and predictors of cardiac perforation in patients receiving CRT-D during the index hospitalization. METHODS: Data were obtained from the National Inpatient Sample, the largest all-player inpatient dataset in the United States. Patients who received CRT-D from 2002 to 2012 were identified using ICD-9 codes. Multivariate analyses were used to identify predictors of cardiac perforation. Complications including in-hospital death and cardiac perforation were identified using ICD-9 codes. RESULTS: A total of 77,827 patients with CRT-D implantation were included into our analysis. After the CRT-D implantation, the in-hospital and rate of cardiac perforation was between 0.24 and 0.48% and had increased significantly (p = 0.02). Although occurrence of cardiac perforation is rare (0.32%), the mortality was 10.6% among those patients with cardiac perforation. In Multivariate analysis identified female as independent risk factors for cardiac perforation (OR: 2.628, 95% CI 1.926-3.585, p < 0.0001). CONCLUSION: Despite rapid progress of the tools and skills for CRT-D implantation, the occurrence of cardiac perforation has not improved. While cardiac perforation is rare, it carries the highest rate of mortality, especially in female patients. Implanting physicians should be familiar with the comorbidities and patient demographics that put them at a higher risk for complications.

Contemporary practice of CRT implantation in scandinavia compared to Europe.

OBJECTIVES: To compare the contemporary practice of CRT implantation in Scandinavia and Europe. DESIGN: We used data from The European CRT Survey II to highlight similarities and differences in the practice of CRT implantation between Europe (EUR) and Scandinavia (SCAND) and between the Scandinavian countries Denmark, Norway and Sweden. Implant data from the national pacemaker registries were used to calculate coverage. RESULTS: The coverage was 24% in SCAND and 11% in EUR. SCAND patients were more often referred from another centre and follow-up was less often to be performed at the operating centre. Telemonitoring was more commonly used. More patients had AV-block or pacemaker dependency/expected high RV pacing percentage as indication for CRT. A CRT-P was more commonly used, and ischaemic aetiology was slightly less common. Echocardiography was more often used to determine LVEF, as well as occlusive venography and placing the RV lead first. In DK implanters tended to choose a septal RV position. Quadripolar leads were more often and a test shock less often used. The paced QRS duration was slightly longer and the narrowing of QRS with CRT more limited. Procedure times and preoperative LVEF were similar. CONCLUSIONS: In Scandinavia AV-conduction disturbance and/or a ventricular pacing indication was a more common indication for CRT, suggesting adaptation of the most recent guidelines ahead of their publication. A test shock was almost never performed, in agreement with recent scientific evidence. CRT-P was more often used, the procedures seem more centralized and quadripolar leads were preferred.

Cardiac resynchronization therapy: a comprehensive review.

Despite improved understanding of heart failure (HF) and advances in medical treatments, its prevalence continues to rise, and the role of implantable devices continues to evolve. While cardiac resynchronization therapy (CRT) is an accepted form of treatment for many suffering from HF, there is an ever-evolving body of evidence examining novel indications, optimization of lead placement and device programming, with several competing technologies now also on the horizon. This review aims to take a clinical perspective on the major trials, current indications, controversies and emerging aspects of CRT in the treatment of HF.

Cardiac contractility modulation treatment in patients with symptomatic heart failure despite optimal medical therapy and cardiac resynchronization therapy (CRT).

BACKGROUND: A significant proportion of patients receiving CRT are non-responders. We evaluated the efficacy of Cardiac Contractility Modulation in subjects with reduced LVEF who, despite cardiac resynchronization therapy (CRT), continued to experience clinically significant symptoms. METHODS: This was a multi-center, open label, treatment-only, feasibility study of 17 CRT non-responders who received CCM therapy. Changes in NYHA class, ejection fraction (EF), Minnesota Living with Heart Failure Questionnaire (MLWHFQ) score, and exercise tolerance (6 minute walk test; 6MWT and peak VO2) were analyzed over 6 months. Mortality and hospitalization rates were determined. RESULTS: Patients (82% male) were 69.4 ±â€¯9.6 years of age with baseline EF = 22.8 ±â€¯6.5%. Among primary endpoints, peak VO2 increased 1.1 ±â€¯1.6 ml/kg/min (p = 0.03) and MLWHFQ improved (-16 ±â€¯16 points; p < 0.01). Mean NYHA class improved (-0.33 ±â€¯0.49; p = 0.02), 6MWT increased (52 ±â€¯60 m; p < 0.01), while EF trended up (2.9 ±â€¯5.8%; p = 0.08) at 6 months. During the 6-month follow-up period, there were 18 hospitalizations in 9 subjects and 2 patients died. CONCLUSIONS: Patients with heart failure and reduced ejection fraction who remain moderately to severely symptomatic despite use of CRT, may benefit from CCM therapy with improvement in quality of life and exercise tolerance. A larger prospective study in this population is warranted.

Facility-Level Variation and Clinical Outcomes in Use of Cardiac Resynchronization Therapy With and Without an Implantable Cardioverter-Defibrillator.

BACKGROUND: Little is known about real-world facility-level preferences for cardiac resynchronization therapy devices with (CRT-D) and without (CRT-P) defibrillator backup. We quantify this variation at the facility level and exploit this variation to compare outcomes of patients receiving these 2 devices. METHODS AND RESULTS: Claims data from fee-for-service Medicare beneficiaries were used to identify new CRT-P and CRT-D implants, 2006 to 2012. We modeled factors associated with receipt of each device, and compared mortality, hospitalizations, and reoperations for patients receiving each using both logistic regression and instrumental variable analysis to account for confounding. Among 71 459 device recipients (CRT-P, 11 925; CRT-D, 59 534; 31% women), CRT-P recipients were older, more likely to be women, and had more comorbidities. Variation in device selection among facilities was substantial: After adjustment for patient characteristics, the odds of receiving a CRT-P (versus CRT-D) device were 7.6× higher for a patient treated at a facility in the highest CRT-P use quartile versus a facility in the lowest CRT-P use quartile. Logistic modeling suggested a survival advantage for CRT-D devices but with falsification end points indicating residual confounding. By contrast, in the instrumental variable analysis using facility variability as the proposed instrument, clinical characteristics and falsification end points were well balanced, and 1-year mortality in patients who received CRT-P versus CRT-D implants did not differ, while CRT-P patients had a lower probability of hospitalizations and reoperations in the year following implant. CONCLUSIONS: CRT-P versus CRT-D selection varies substantially among facilities, adjusted for clinical factors. After instrumental variable adjustment for clinical covariates and facility preference, survival was no different between the devices. Therefore, CRT-P may be preferred for Medicare beneficiaries considering new CRT implantation.

Cardiac resynchronization therapy in congenital heart disease: Results from the German National Register for Congenital Heart Defects.

BACKGROUND: Cardiac resynchronization therapy (CRT) is an established option for patients with heart failure. Limited data exists on indications and outcome of CRT in contemporary congenital heart disease (CHD) patients. METHODS AND RESULTS: All patients with CRT registered in the German National Register for Congenital Heart Defects were systematically identified. We analysed data on demographics, type of congenital defect as well as repair, associated conditions, indication for CRT, heart failure medication, combination with a defibrillator or pacemaker and outcome. Overall, 65 patients with CRT were identified. The most common congenital diagnoses were Tetralogy of Fallot (n = 11), congenitally corrected transposition of the great arteries (ccTGA) (n = 9) and double outlet right ventricle (n = 6). The majority of patients (n = 48, 87%) had conventional antibradycardia pacing or ICD indications. Of these, the majority (n = 44) underwent an upgrade to a CRT system to avoid the detrimental consequences of longstanding conventional ventricular single-site pacing, whereas four patients required an ICD due to heart failure and a history of malignant ventricular tachycardia. During a median follow-up of 6.9 years 19 patients developed complications: 16 patients experienced pacemaker lead dysfunction and 3 patients pacemaker infection. CONCLUSIONS: The current study based on a large national register for CHD shows that CRT is feasible and can be used as an adjunct in the heart failure treatment of selected CHD patients. Uptake of this therapy proved to be low in this nationwide study and CRT implantation was largely used in patients with a pre-existing pacing indication or those requiring an ICD.

Cessation of pacing in super-responders of cardiac resynchronization therapy: A randomized controlled trial.

BACKGROUND: The consequence of cessation of biventricular pacing in super-responders of cardiac resynchronization therapy (CRT) has not been fully investigated. METHODS: In this prospective, single-blinded clinical trial, 21 super-responders were randomly assigned to the ceased pacing (CeP, 11 patients) group or the continued pacing (CoP, 10 patients) group. Patients randomized to the CeP group underwent cessation of biventricular pacing. New York Heart Association (NYHA) class, quality of life (QOL) assessed with Minnesota questionnaire, 6-minute walking distance (6MWD), left ventricular end systolic volume (LVESV), left ventricular end-diastolic volume (LVEDV), and left ventricular ejection fraction (LVEF) were compared between groups at 3- and 6-month follow-up. RESULTS: No significant difference was observed between the CeP and CoP groups regarding NYHA class, QOL, 6MWD, LVESV, LVEDV, or LVEF after 3 months (all P > 0.05). After 6 months, there existed no significant difference between the CeP and CoP groups with regard to NYHA class, QOL, 6MWD, LVESV, and LVEDV (all P > 0.05); however, LVEF was significantly lower in the CeP group than that of the CoP group (0.49 ± 0.10 vs 0.60 ± 0.11, P = 0.04), and LVEF was significantly reduced in the CeP group compared with the baseline value at randomization (0.49 ± 0.10 vs 0.54 ± 0.06, P = 0.04). CONCLUSION: LVEF was significantly reduced in super-responders of CRT 6 months after cessation of pacing. Super-responders to CRT should receive continued, long-term pacing to preserve recovered LV function.

Incidence and outcomes of cardiac tamponade in patients undergoing cardiac resynchronization therapy.

INTRODUCTION: Cardiac tamponade is a severe complication of cardiac resynchronization therapy (CRT) implantations. We provide a contemporary large-scale study evaluating the incident trends, predictors and impact of cardiac tamponade in patients undergoing CRT. METHOD: Data were obtained from the Nationwide Inpatient Sample (NIS) of 2007 through 2014. Trends in the annual rates of tamponades in CRT implantation were assessed using negative binomial regressions. Hierarchical mixed-effects logistic regression models were built to determine the independent predictors of tamponade in CRT implantation and 1:1 propensity-matched analysis performed to examine the impact of tamponade on outcomes. RESULT: An estimated 310,704 CRT implantations were performed in the United States between 2007 and 2014, out of which 536 patients (0.17%) developed procedure-related cardiac tamponade. A significant increasing trend in the tamponade incidence was observed over the 8-year study period [1.65 per 10,000 CRT implantation in 2007 to 38.16 in 2014 (p < 0.001)]. After multivariable adjustment, female sex and coagulation disorder were found to be independently associated with higher odds of tamponade. Conversely, prior history of CABG procedure was associated with lower odds of tamponade. CRT complicated with tamponade had significantly increased in-hospital mortality, bleeding requiring transfusion, prolonged hospital stay and increased cost. CONCLUSION: We found an increasing trend in the incidence of post CRT tamponade among hospitalized patients between 2007 and 2014. Female gender and coagulation disorder were associated with the development of tamponade among recipients of CRT. Risk stratification of patients who are undergoing CRT is crucial to improving outcome in CRT implantation.

The definition of left bundle branch block influences the response to cardiac resynchronization therapy.

BACKGROUND: CRT has been proven to achieve most benefit in patients with left bundle branch block morphology (LBBB). However, ECG criteria to define LBBB significantly differ from each other. Objective of the study was to evaluate the impact of different ECG criteria for LBBB definition on survival, hospitalization for heart failure and reverse remodelling in patients who received cardiac resynchronization therapy (CRT). METHODS AND RESULTS: Three-hundred-sixteen consecutive patients were included in the analysis. Six different classifications were assessed in baseline ECGs of patients who received a CRT device: a QRS duration of ≥150 ms and LBBB according to AHA/ACC/HRS, ESC 2006, ESC 2009, ESC 2013 and the classification proposed by Strauss and colleagues. In univariate analysis, the ESC 2009 and 2013 and the Strauss classifications were significantly associated with a reduction in cumulative probability for heart failure (HF) and mortality (HR 0.60, 95%CI 0.42-0.86, HR 0.61, 95% CI 0.43-0.87 and HR 0.57, 95% CI 0.40-0.80, respectively). In multivariate analysis, the association with the combined endpoint was confirmed only for ESC 2009 and 2013 classifications and for Strauss. Moreover, the cumulative probability of all-cause death and HF hospitalizations was higher in patients who were negative for all the 5 LBBB classifications. CONCLUSIONS: This study shows that the strength of the association of LBBB to outcome in CRT depends on the ECG classifications used to define LBBB, the simplest criteria (ESC 2009 and 2013) providing the best association with clinical endpoints in CRT.