2012 EHRA/HRS expert consensus statement on cardiac resynchronization therapy in heart failure: implant and follow-up recommendations and management

Cardiac resynchronization therapy for patients with cardiac sarcoidosis

Aims

Sarcoidosis with cardiac involvement is a rare pathological condition, and therefore cardiac resynchronization therapy (CRT) for patients with cardiac sarcoidosis is even further rare. We aimed to clarify the clinical features of patients with cardiac sarcoidosis who received CRT.

Methods and results

We retrospectively reviewed the clinical data on CRT at three cardiovascular centres to detect cardiac sarcoidosis patients. We identified 18 (8.9%) patients with cardiac sarcoidosis who met the inclusion criteria out of 202 with systolic heart failure who received CRT based on the guidelines. The majority of the patients were female [15 (83.3%)] and underwent an upgrade from a pacemaker or implantable cardioverter defibrillator [13 (72.2%)]. We found 1 (5.6%) cardiovascular death during the follow-up period (mean ± SD, 4.7 ± 3.0 years). Seven (38.9%) patients had a composite outcome of cardiovascular death or hospitalization from worsening heart failure within 5 years after the CRT. Twelve (66.7%) patients had a history of sustained ventricular arrhythmias or those occurring after the CRT. Among the overall patients, no significant improvement was found in either the end-systolic volume or left ventricular ejection fraction (LVEF) 6 months after the CRT. A worsening LVEF was, however, more likely to be seen in 5 (27.8%) patients with ventricular arrhythmias after the CRT than in those without (P = 0.04). An improved clinical composite score was seen in 10 (55.6%) patients.

Conclusions

Cardiac sarcoidosis patients receiving CRT may have poor LV reverse remodelling and a high incidence of ventricular arrhythmias.

Refining success of cardiac resynchronization therapy using a simple score predicting the amount of reverse ventricular remodelling: results from the Markers and Response to CRT (MARC) study

Aims

Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in systolic heart failure patients with ventricular conduction delay. Variability of individual response to CRT warrants improved patient selection. The Markers and Response to CRT (MARC) study was designed to investigate markers related to response to CRT.

Methods and results

We prospectively studied the ability of 11 clinical, 11 electrocardiographic, 4 echocardiographic, and 16 blood biomarkers to predict CRT response in 240 patients. Response was measured by the reduction of indexed left ventricular end-systolic volume (LVESVi) at 6 months follow-up. Biomarkers were related to LVESVi change using log-linear regression on continuous scale. Covariates that were significant univariately were included in a multivariable model. The final model was utilized to compose a response score. Age was 67 ± 10 years, 63% were male, 46% had ischaemic aetiology, LV ejection fraction was 26 ± 8%, LVESVi was 75 ± 31 mL/m2, and QRS was 178 ± 23 ms. At 6 months LVESVi was reduced to 58 ± 31 mL/m2 (relative reduction of 22 ± 24%), 130 patients (61%) showed ≥ 15% LVESVi reduction. In univariate analysis 17 parameters were significantly associated with LVESVi change. In the final model age, QRSAREA (using vectorcardiography) and two echocardiographic markers (interventricular mechanical delay and apical rocking) remained significantly associated with the amount of reverse ventricular remodelling. This CAVIAR (CRT-Age-Vectorcardiographic QRSAREA -Interventricular Mechanical delay-Apical Rocking) response score also predicted clinical outcome assessed by heart failure hospitalizations and all-cause mortality.

Conclusions

The CAVIAR response score predicts the amount of reverse remodelling after CRT and may be used to improve patient selection. Clinical Trials: NCT01519908.

Myocardial strain computed at multiple spatial scales from tagged magnetic resonance imaging: Estimating cardiac biomarkers for CRT patients

Abnormal cardiac motion can indicate different forms of disease, which can manifest at different spatial scales in the myocardium. Many studies have sought to characterise particular motion abnormalities associated with specific diseases, and to utilise motion information to improve diagnoses. However, the importance of spatial scale in the analysis of cardiac deformation has not been extensively investigated. We build on recent work on the analysis of myocardial strains at different spatial scales using a cardiac motion atlas to find the optimal scales for estimating different cardiac biomarkers. We apply a multi-scale strain analysis to a 43 patient cohort of cardiac resynchronisation therapy (CRT) patients using tagged magnetic resonance imaging data for (1) predicting response to CRT, (2) identifying septal flash, (3) estimating QRS duration, and (4) identifying the presence of ischaemia. A repeated, stratified cross-validation is used to demonstrate the importance of spatial scale in our analysis, revealing different optimal spatial scales for the estimation of different biomarkers.

Comparison of strain parameters in dyssynchronous heart failure between speckle tracking echocardiography vendor systems

Background

Although mechanical dyssynchrony parameters derived by speckle tracking echocardiography (STE) may predict response to cardiac resynchronization therapy (CRT), comparability of parameters derived with different STE vendors is unknown.

Methods

In the MARC study, echocardiographic images of heart failure patients obtained before CRT implantation were prospectively analysed with vendor specific STE software (GE EchoPac and Philips QLAB) and vendor-independent software (TomTec 2DCPA). Response was defined as change in left ventricular (LV) end-systolic volume between examination before and six-months after CRT implantation. Basic longitudinal strain and mechanical dyssynchrony parameters (septal to lateral wall delay (SL-delay), septal systolic rebound stretch (SRSsept), and systolic stretch index (SSI)) were obtained from either separate septal and lateral walls, or total LV apical four chamber. Septal strain patterns were categorized in three types. The coefficient of variation and intra-class correlation coefficient (ICC) were analysed. Dyssynchrony parameters were associated with CRT response using univariate regression analysis and C-statistics.

Results

Two-hundred eleven patients were analysed. GE-cohort (n = 123): age 68 years (interquartile range (IQR): 61–73), 67% male, QRS-duration 177 ms (IQR: 160–192), LV ejection fraction: 26 ± 7%. Philips-cohort (n = 88): age 67 years (IQR: 59–74), 60% male, QRS-duration: 179 ms (IQR: 166–193), LV ejection fraction: 27 ± 8. LV derived peak strain was comparable in the GE- (GE: -7.3 ± 3.1%, TomTec: −6.4 ± 2.8%, ICC: 0.723) and Philips-cohort (Philips: −7.7 ± 2.7%, TomTec: −7.7 ± 3.3%, ICC: 0.749). SL-delay showed low ICC values (GE vs. TomTec: 0.078 and Philips vs. TomTec: 0.025). ICC’s of SRSsept and SSI were higher but only weak (GE vs. TomTec: SRSsept: 0.470, SSI: 0.467) (Philips vs. QLAB: SRSsept: 0.419, SSI: 0.421). Comparability of septal strain patterns was low (Cohen’s kappa, GE vs. TomTec: 0.221 and Philips vs. TomTec: 0.279). Septal strain patterns, SRSsept and SSI were associated with changes in LV end-systolic volume for all vendors. SRSsept and SSI had relative varying C-statistic values (range: 0.530–0.705) and different cut-off values between vendors.

Conclusions

Although global longitudinal strain analysis showed fair comparability, assessment of dyssynchrony parameters was vendor specific and not applicable outside the context of the implemented platform. While the standardization taskforce took an important step for global peak strain, further standardization of STE is still warranted.

Electronic supplementary material

The online version of this article (10.1186/s12947-017-0116-5) contains supplementary material, which is available to authorized users.

Comparison of strain imaging techniques in CRT candidates: CMR tagging, CMR feature tracking and speckle tracking echocardiography

Parameters using myocardial strain analysis may predict response to cardiac resynchronization therapy (CRT). As the agreement between currently available strain imaging modalities is unknown, three different modalities were compared. Twenty-seven CRT-candidates, prospectively included in the MARC study, underwent cardiac magnetic resonance (CMR) imaging and echocardiographic examination. Left ventricular (LV) circumferential strain was analysed with CMR tagging (CMR-TAG), CMR feature tracking (CMR-FT), and speckle tracking echocardiography (STE). Basic strain values and parameters of dyssynchrony and discoordination obtained with CMR-FT and STE were compared to CMR-TAG. Agreement of CMR-FT and CMR-TAG was overall fair, while agreement between STE and CMR-TAG was often poor. For both comparisons, agreement on discoordination parameters was highest, followed by dyssynchrony and basic strain parameters. For discoordination parameters, agreement on systolic stretch index was highest, with fair intra-class correlation coefficients (ICC) (CMR-FT: 0.58, STE: 0.55). ICC of septal systolic rebound stretch (SRS_sept) was poor (CMR-FT: 0.41, STE: 0.30). Internal stretch factor of septal and lateral wall (ISF_sep-lat) showed fair ICC values (CMR-FT: 0.53, STE: 0.46), while the ICC of the total LV (ISF_LV) was fair for CMR-FT (0.55) and poor for STE (ICC: 0.32). The CURE index had a fair ICC for both comparisons (CMR-FT: 0.49, STE 0.41). Although comparison of STE to CMR-TAG was limited by methodological differences, agreement between CMR-FT and CMR-TAG was overall higher compared to STE and CMR-TAG. CMR-FT is a potential clinical alternative for CMR-TAG and STE, especially in the detection of discoordination in CRT-candidates.

A comparison of the different features of quadripolar left ventricular pacing leads to deliver cardiac resynchronization therapy

INTRODUCTION

Cardiac Resynchronization therapy (CRT) improves the quality of life and reduces morbidity and mortality of certain patients with heart failure. However, not all patients respond positively after CRT and about one third of cases do not experience benefit. Suboptimal biventricular pacing may account for this and quadripolar left ventricular (LV) leads have emerged in the last years to address issues relating to inadequate delivery of CRT.

AREAS COVERED

This review article concisely summarizes the main technical characteristics of the quadripolar LV leads either currently available in the market today or under final stages of development. Focus is given in recent advancements in the area and challenging aspects and controversies, future implications as well as opportunities for further development.

EXPERT COMMENTARY

Quadripolar LV pacing leads have now become the standard of care in CRT. Currently a multitude of lead options is available to the clinician. The selection process of the most appropriate lead is far from the 'one size fits all' concept. Further development of quadripolar LV leads is currently ongoing and it is anticipated to contribute towards the release of more technologically advantageous leads which will enable the delivery of optimal CRT therapy with the lowest rate of complications.

Incremental benefit of cardiac resynchronisation therapy with versus without a defibrillator

OBJECTIVE

To determine the incremental value of implantable cardioverter defibrillators (ICD) in contemporary optimally treated patients with heart failure (HF) undergoing cardiac resynchronisation therapy (CRT).

METHODS

Consecutive patients with HF undergoing CRT-pacemaker (CRT-P) or CRT-defibrillator (CRT-D) implantation in a single tertiary care centre between October 2008 and August 2015 were retrospectively evaluated. For patients with a primary prevention indication of the CRT-D, no benefit of the ICD was defined as absence of appropriate therapy (device analysis) or lethal ventricular tachyarrhythmias (mode of death analysis) during follow-up.

RESULTS

687 patients (CRT-P/CRT-D; n=361/326) were followed for 38±22 months. CRT-P recipients were older (75.7±9.1 vs 71.8±9.3 years; p<0.001) and had a higher comorbidity burden. Five patients with CRT-P (1%) experienced episodes of sustained ventricular-tachycardia vs 64 (20%) patients with CRT-D (p<0.001). Remote tele-monitoring detected the episodes of sustained ventricular tachycardia in four patients with CRT-P, allowing for elective upgrade to CRT-D. All-cause mortality was higher in patients with CRT-P versus CRT-D (21% vs 12%, p=0.003), even after adjusting for baseline characteristics (HR 2.5; 95% CI 1.36 to 4.60; p=0.003). However, mode of death analysis revealed a predominant non-cardiac mode of death in CRT-P recipients (n=47 (71%) vs n=13 (38%) in CRT-D, p=0.002). Multivariate analysis revealed that age >80 years, New York Heart Association class IV, intolerance to beta-blockers and underlying non-ischaemic cardiomyopathy were independently associated with little incremental value of a primary prevention ICD on top of CRT.

CONCLUSIONS

The majority of patients with contemporary HF as currently selected for CRT-P exhibit mainly non-cardiac-driven mortality. Weighing risk of ventricular-tachyarrhythmic death versus risk of all-cause mortality helps to address the incremental value of an ICD to CRT-P.

Implantable Cardioverter-Defibrillators With Versus Without Resynchronization Therapy in Patients With a QRS Duration >180 ms

BACKGROUND

More than 20% of Medicare beneficiaries receiving cardiac resynchronization therapy defibrillators (CRT-D) have a very wide (≥180 ms) QRS complex duration (QRSD). Outcomes of CRT-D in these patients are not well-established because they have been underrepresented in clinical trials.

OBJECTIVES

This study examined outcomes in patients with CRT-D in a very wide QRSD with left bundle branch block (LBBB) versus those without LBBB.

METHODS

Medicare patients from the Implantable Cardioverter Defibrillator Registry (January 1, 2005, through April 30, 2006) with a CRT-D and confirmed Class I or IIa indications for CRT-D were matched to implantable cardioverter-defibrillator (ICD) patients without CRT despite having Class I or IIa indications for CRT. Mortality and heart failure hospitalizations longer than 4 years with CRT-D versus standard ICDs based on a QRSD and morphology were analyzed.

RESULTS

We analyzed 24,960 patients. Among those with LBBB, patients with a QRSD ≥180 ms had a greater adjusted survival benefit with CRT-D versus standard ICD (hazard ration [HR] for death: 0.65; 95% confidence interval [CI]: 0.59 to 0.72) compared with those having a QRSD 120 to 149 ms (HR: 0.85; 95% CI: 0.80 to 0.92) and 150 to 179 ms (HR: 0.87; 95% CI: 0.81 to 0.93). CRT-D versus ICD was associated with an improvement in survival in those with LBBB and a QRSD ≥180 ms (adjusted HR for death: 0.78; 95% CI: 0.68 to 0.91), but not in those with LBBB and a QRSD 150 to 179 ms (adjusted HR for death: 1.06; 95% CI: 0.95 to 1.19).

CONCLUSIONS

Improvements in both survival and heart failure hospitalizations with CRT-D were greatest in patients with a QRSD ≥180 ms with or without LBBB, whereas patients with a QRSD 150 to 179 ms without LBBB had no improvement in survival with CRT-D, and those with a QRSD 150 to 179 ms and LBBB had only a modest improvement.

Safety and efficacy of DOACs vs acenocoumarol in patients undergoing catheter ablation of atrial fibrillation

BACKGROUND

Thromboembolic complications can be life-threatening during atrial fibrillation (AF) catheter ablation. The aim of our study was to evaluate the safety and efficacy of continuous treatment using direct oral anticoagulants (DOACs) as an alternative to uninterrupted acenocoumarol for periprocedural anticoagulation.

HYPOTHESIS

Continuous treatment with DOACs has similar safety and efficacy compared to acenocoumarol.

METHODS

We enrolled 474 patients (mean age, 58 years; 68.4% male) undergoing AF catheter ablation between June 2013 and December 2016. All patients were equally assigned to take acenocoumarol (group 1, 136 patients) or DOACs (group 2, 338 patients) for ≥2 months before the procedure. We compared thromboembolic and bleeding complications between the 2 groups.

RESULTS

Our analysis showed no significant difference in major and minor complications between the 2 patient groups. Specifically, 3 of 136 patients (2.2%) using uninterrupted acenocoumarol had a major complication (1 patient [0.7%] had transient ischemic attack resolved 8 hours later, 1 [0.7%] had pericardial tamponade, and 1 [0.7%] had a subcapsular renal hematoma) and 2 patients (1.4%) had minor complications (1 [0.7%] pseudoaneurysm and 1 [0.7%] groin hematoma). In group 2, 1 of 338 patients (0.3%) had a major complication (transient ischemic attack). In the same group, 7 patients (2.1%) had a minor complication (1 patient [0.3%] presented with pseudoaneurysm, 4 [1.2%] with pericardial effusion <1 cm, 1 [0.3%] femoral arteriovenous fistula between the femoral artery and femoral vein, and 1 [0.7%] groin hematoma).

CONCLUSIONS

DOACs and acenocoumarol have similar safety and effectiveness regarding thromboembolic complications prevention without increasing bleeding complications.

Comprehensive use of cardiac computed tomography to guide left ventricular lead placement in cardiac resynchronization therapy

Background

Optimal lead positioning is an important determinant of cardiac resynchronization therapy (CRT) response.

Objective

The purpose of this study was to evaluate cardiac computed tomography (CT) selection of the optimal epicardial vein for left ventricular (LV) lead placement by targeting regions of late mechanical activation and avoiding myocardial scar.

Methods

Eighteen patients undergoing CRT upgrade with existing pacing systems underwent preimplant electrocardiogram-gated cardiac CT to assess wall thickness, hypoperfusion, late mechanical activation, and regions of myocardial scar by the derivation of the stretch quantifier for endocardial engraved zones (SQUEEZ) algorithm. Cardiac venous anatomy was mapped to individualized American Heart Association (AHA) bull’s-eye plots to identify the optimal venous target and compared with acute hemodynamic response (AHR) in each coronary venous target using an LV pressure wire.

Results

Fifteen data sets were evaluable. CT-SQUEEZ–derived targets produced a similar mean AHR compared with the best achievable AHR (20.4% ± 13.7% vs 24.9% ± 11.1%; P = .36). SQUEEZ-derived guidance produced a positive AHR in 92% of target segments, and pacing in a CT-SQUEEZ target vein produced a greater clinical response rate vs nontarget segments (90% vs 60%).

Conclusion

Preprocedural CT-SQUEEZ–derived target selection may be a valuable tool to predict the optimal venous site for LV lead placement in patients undergoing CRT upgrade.

Defibrillators: Selecting the Right Device for the Right Patient

Advances in the field of defibrillation have brought to practice different types of devices that include the transvenous implantable cardioverter-defibrillator (ICD) with or without cardiac resynchronization therapy, the subcutaneous ICD (S-ICD), and the wearable cardioverter-defibrillator. To ensure optimal use of these devices and to achieve best patient outcomes, clinicians need to understand how these devices work, learn the characteristics of patients who qualify them for one type of device versus another, and recognize the remaining gaps in knowledge surrounding these devices. The transvenous ICD has been shown in several randomized clinical trials to improve the survival of patients resuscitated from near-fatal ventricular fibrillation and those with sustained ventricular tachycardia with syncope or systolic heart failure as a result of ischemic or nonischemic cardiomyopathy despite receiving guideline-directed medical therapy. Important gaps in knowledge regarding the transvenous ICD involve the role of the ICD in patient subgroups not included, or not well represented, in clinical trials and the need to refine the selection criteria for the ICD in patients who are indicated for it. S-ICDs were recently introduced into the clinical arena as another option for many patients who have an approved indication for a transvenous ICD. The main advantage of the S-ICD is a lower risk of infection and lead-related complications; however, the S-ICD does not offer bradycardia or antitachycardia pacing. The S-ICD may be ideal for patients with limited vascular access, high infection risk, or some congenital heart diseases. However, more data are needed regarding the efficacy and effectiveness of the S-ICD in comparison to transvenous ICDs, the extent of defibrillation testing required, and the use of the S-ICD with other novel technologies, including leadless pacemakers. Cardiac resynchronization therapy-defibrillators are indicated in patients with a left ventricular ejection fraction ≤35%, QRS width ≥130 ms, and New York Heart Association class II, III, or ambulatory IV symptoms despite treatment with guideline-directed medical therapy. Multiple randomized controlled trials have shown that the cardiac resynchronization therapy-defibrillator improves survival, quality of life, and several echocardiographic measures. One main challenge related to cardiac resynchronization therapy-defibrillators is the 30% nonresponse rate. Many initiatives are underway to address this challenge including improved cardiac resynchronization therapy and imaging technologies and enhanced selection of patients and device programming.

Real-Time X-MRI-Guided Left Ventricular Lead Implantation for Targeted Delivery of Cardiac Resynchronization Therapy

OBJECTIVES

This study sought to test the feasibility of a purpose-built, integrated software platform to process, analyze, and overlay cardiac magnetic resonance (CMR) data in real time within a combined cardiac catheter laboratory and magnetic resonance imaging scanner suite (X-MRI) to guide left ventricular (LV) lead implantation.

BACKGROUND

Suboptimal LV lead position is a major determinant of poor cardiac resynchronization therapy (CRT) response, and the optimal site is highly patient specific. Pacing myocardial scar is associated with poorer outcomes; conversely, targeting latest mechanical activation (LMA) may improve them.

METHODS

Fourteen patients (age 74 ± 5.1 years; New York Heart Association functional class: 2.7 ± 0.4; 86% ischemic with ejection fraction 27 ± 7.6%; QRSd: 157 ± 19 ms) underwent CMR followed by immediate CRT implantation using derived scar and dyssynchrony data, overlaid onto fluoroscopy in an X-MRI suite. Rapid LV segmentation enabled detailed scar quantification, identification of LMA segments, and selection of myocardial targets. At coronary venography, the CMR-derived 3-dimensional shell was fused, enabling identification of viable venous targets subtended by target segments for LV lead placement.

RESULTS

The platform was successful in all 14 patients, of whom 10 (71%) were paced in pre-procedurally defined target segments. Pacing in CMR-defined target segments (out of scar) showed a significant decrease in the LV capture threshold (mean difference: 2.4 [1.5 to 3.2]; p < 0.001) and shorter paced QRS duration (mean difference: 25 [15 to 34]; p < 0.001) compared with pacing in areas of CMR determined scar. In 5 (36%) patients with extensive scar in the posterolateral wall, CMR guidance enabled successful lead delivery in an alternative anatomically favorable site. Radiation dose and implant times were similar to historical controls (p = NS).

CONCLUSIONS

Real-time CMR-guided LV lead placement is feasible and achievable in a single clinical setting and may prove helpful to preferentially select sites for LV lead placement.

Impact of basal inferolateral scar burden determined by automatic analysis of 99mTc-MIBI myocardial perfusion SPECT on the long-term prognosis of cardiac resynchronization therapy

AIMS

Left-ventricular (LV) scarring may be associated with a poor response to cardiac resynchronization therapy (CRT). The automatic analysis of myocardial perfusion single-photon emission computed tomography (MP-SPECT) may provide objective quantification of LV scarring. We investigated the impact of LV scarring determined by an automatic analysis of MP-SPECT on short-term LV volume response as well as long-term outcome.

METHODS AND RESULTS

We studied consecutive 51 patients who were eligible to undergo 99mTc-MIBI MP-SPECT both at baseline and 6 months after CRT (ischaemic cardiomyopathies 31%). Quantitative perfusion SPECT was used to evaluate the defect extent (an index of global scarring) and the LV 17-segment regional uptake ratio (an inverse index of regional scar burden). The primary outcome was the composite of overall mortality or first hospitalization for worsening heart failure. A high global scar burden and a low mid/basal inferolateral regional uptake ratio were associated with volume non-responders to CRT at 6 months. The basal inferolateral regional uptake ratio remained as a predictor of volume non-response after adjusting for the type of cardiomyopathy. During a median follow-up of 36.1 months, the outcome occurred in 28 patients. The patients with a low basal inferolateral regional uptake ratio with a cutoff value of 57% showed poor prognosis (log-rank P= 0.006).

CONCLUSION

The scarring determined by automatic analysis of MP-SPECT images may predict a poor response to CRT regardless of the pathogenesis of cardiomyopathy. The basal inferolateral scar burden in particular may have an adverse impact on long-term prognosis.

Cardiac Resynchronization Therapy: An Overview on Guidelines

Cardiac resynchronization therapy (CRT) is included in international consensus guidelines as a treatment with proven efficacy in well-selected patients on top of optimal medical therapy. Although all the guidelines strongly recommend CRT for LBBB with QRS duration greater than 150 milliseconds, lower strength of recommendation is reported for QRS duration of 120 to 150 milliseconds, especially if not associated with LBBB. CRT is not recommended for a QRS of less than 120 milliseconds. No indication emerges for guiding the implant based on echocardiographic evaluation of dyssynchrony. Many data indicate that CRT is underused and there is heterogeneity in its implementation.

[Current impact of cardiac implantable electronic devices]

Sudden cardiac death and chronic heart failure are among the main contributors to persisting high mortality rates in Germany. In addition to removal of causal factors and guideline-conform pharmacological therapy, therapy with cardiac implantable electronic devices (CIED) is of undisputed importance. Subcutaneous defibrillators have the advantage that they do not have intracardiac electrodes but still have the same efficacy and safety. For patients with a wide QRS complex and reduced ejection fraction, cardiac resynchronization has led to a reduction of morbidity and mortality. For patients with a normal QRS complex, cardiac contractility modulation had been shown to improve the quality of life, exercise capacity and left ventricular function. As a procedure for autonomic modulation in patients with reduced cardiac strength, the data for baroreceptor stimulation are the most convincing.

Using three-dimensional echocardiography to guide left ventricle lead position in cardiac resynchronization therapy: does it make any difference

BACKGROUND

Cardiac resynchronization therapy (CRT) is an effective treatment for patients with advanced heart failure. Nearly 30% of candidates are inadequate responders. Proper patient selection, left ventricle (LV) lead placement optimization, and optimization of the programming of the CRT device are important approaches to improve outcome of CRT. We examined the role of three-dimensional (3D) echocardiography in determining the optimal LV lead position as a method of optimizing CRT response.

METHODS

Forty-seven patients with a mean age of 60.2 ± 11.1 years including five (10.6%) females, all having advanced CHF (EF <35%, LBBB >120 mesc, or non-LBBB >150 msec, with NYHA II-III or ambulatory class IV) were enrolled. Detailed history (NYHA class, Minnesota living with heart failure questionnaire), clinical examination, 6-min walk test, and standard 2D echocardiography were done in all cases. 3D echo detailed analysis of the LV 16 segments was done to determine the latest wall to reach the minimal systolic volume. Multisite pacing was done blind to the 3D echo data achieving a stable LV lead position in mid LV segment. This exact fluoroscopic site was determined (in two orthogonal views) and correlated with 3D most delayed area using a resized 16-segment schema. Patients were classified retrospectively into group A with concordance between the delayed LV area and LV lead position and group B with discordance between both. Patients were followed up after 3-6 (5.1 ± 1.8) months. Patients with reduction of 2D LV end-systolic volume of ≥10% at follow-up were termed volumetric responders. Poorly echogenic patients and those with decompensated NYHA class IV, sustained atrial arrhythmias, and rheumatic or congenital heart diseases were excluded.

RESULTS

LV lead placement was concordant in 22 (46.8%) cases. After the follow-up period, 31 (65.9%) of the study population were considered volumetric responders with no significant difference among both groups (14 (63.3%) in group A vs 17 (68%) in group B, p > 0.05). CRT insertion resulted in significant improvement of NYHA class in 36 (76.5%) cases, 6-min walk test (447.2 ± 127.0 vs 369.6 ± 87.5 m, p < 0.01), MLHFQ (58.1 ± 19.7 vs 69.6 ± 13.5, p < 0.01), QRS duration (131.2 ± 13.8 vs 149.4 ± 16 msec, p < 0.01), 2D LV EF 33.0 ± 9.5 vs 25.3 ± 6.5, p < 0.001), LVESV (156.0 ± 82.9 vs177.6 ± 92.7 ml, p < 0.05), and 3D LVEF (29.1 ± 9.0 vs 23.6 ± 5.9, p < 0.001) irrespective of the etiology of heart failure. However, there were no significant differences between both groups regarding the same parameters (6-min walk test 470.8 ± 128.7 vs 428.3 ± 126.8 m, MLHFQ 56.8 ± 20.0 vs 58.11 ± 19.0, QRS duration 129.9 ± 12.4 vs 132.1 ± 15.1 msec, 2D LVEF 30.9 ± 8.3 vs 34.58 ± 10.9, LVESV 173.0 ± 110.0 vs 143.0 ± 67.9, 3D LVEF 26 ± 8 vs 31 ± 9, for groups A and B, respectively, p < 0.05).

CONCLUSIONS

Standard anatomical LV lead placement remains a simple, practical, and effective method in patients undergoing CRT. 3D echocardiography-guided LV lead placement added no clinical benefit compared to standard techniques.

Optimized Left Ventricular Endocardial Stimulation Is Superior to Optimized Epicardial Stimulation in Ischemic Patients With Poor Response to Cardiac Resynchronization Therapy: A Combined Magnetic Resonance Imaging, Electroanatomic Contact Mapping, and Hemodynamic Study to Target Endocardial Lead Placement

OBJECTIVES

The purpose of this study was to identify the optimal pacing site for the left ventricular (LV) lead in ischemic patients with poor response to cardiac resynchronization therapy (CRT).

BACKGROUND

LV endocardial pacing may offer benefit over conventional CRT in ischemic patients.

METHODS

We performed cardiac magnetic resonance, invasive electroanatomic mapping (EAM), and measured the acute hemodynamic response (AHR) in patients with existing CRT systems.

RESULTS

In all, 135 epicardial and endocardial pacing sites were tested in 8 patients. Endocardial pacing was superior to epicardial pacing with respect to mean AHR (% change in dP/dt_max vs. baseline) (11.81 [-7.2 to 44.6] vs. 6.55 [-11.0 to 19.7]; p = 0.025). This was associated with a similar first ventricular depolarization (Q-LV) (75 ms [13 to 161 ms] vs. 75 ms [25 to 129 ms]; p = 0.354), shorter stimulation-QRS duration (15 ms [7 to 43 ms] vs. 19 ms [5 to 66 ms]; p = 0.010) and shorter paced QRS duration (149 ms [95 to 218 ms] vs. 171 ms [120 to 235 ms]; p < 0.001). The mean best achievable AHR was higher with endocardial pacing (25.64 ± 14.74% vs. 12.64 ± 6.76%; p = 0.044). Furthermore, AHR was significantly greater pacing the same site endocardially versus epicardially (15.2 ± 10.7% vs. 7.6 ± 6.3%; p = 0.014) with a shorter paced QRS duration (137 ± 22 ms vs. 166 ± 30 ms; p < 0.001) despite a similar Q-LV (70 ± 38 ms vs. 79 ± 34 ms; p = 0.512). Lack of capture due to areas of scar (corroborated by EAM and cardiac magnetic resonance) was associated with a poor AHR.

CONCLUSIONS

In ischemic patients with poor CRT response, biventricular endocardial pacing is superior to epicardial pacing. This may reflect accessibility to sites that cannot be reached via coronary sinus anatomy and/or by access to more rapidly conducting tissue. Furthermore, guidance to the optimal LV pacing site may be aided by modalities such as cardiac magnetic resonance to target delayed activating sites while avoiding scar.

A framework for combining a motion atlas with non-motion information to learn clinically useful biomarkers: Application to cardiac resynchronisation therapy response prediction

We present a framework for combining a cardiac motion atlas with non-motion data. The atlas represents cardiac cycle motion across a number of subjects in a common space based on rich motion descriptors capturing 3D displacement, velocity, strain and strain rate. The non-motion data are derived from a variety of sources such as imaging, electrocardiogram (ECG) and clinical reports. Once in the atlas space, we apply a novel supervised learning approach based on random projections and ensemble learning to learn the relationship between the atlas data and some desired clinical output. We apply our framework to the problem of predicting response to Cardiac Resynchronisation Therapy (CRT). Using a cohort of 34 patients selected for CRT using conventional criteria, results show that the combination of motion and non-motion data enables CRT response to be predicted with 91.2% accuracy (100% sensitivity and 62.5% specificity), which compares favourably with the current state-of-the-art in CRT response prediction.

Mode of Death in Octogenarians Treated With Cardiac Resynchronization Therapy

BACKGROUND

Cardiac resynchronization therapy (CRT) improves morbidity and mortality in heart failure with reduced ejection fraction (HFrEF) and electrical dyssynchrony. CRT patients in clinical practice are older compared with clinical trials.

OBJECTIVE

To investigate clinical response, reverse remodeling, outcome, and mode of death in octogenarians receiving CRT.

METHODS

Baseline characteristics, change in New York Heart Association (NYHA) functional class, reverse ventricular remodeling, heart failure readmissions, all-cause mortality, and mode of death were evaluated in CRT patients with comparison between octogenarians and nonoctogenarians. In addition, annual mortality rates of octogenarians undergoing CRT were compared with age-matched control subjects from the general population with the use of national actuarial tables.

RESULTS

A total of 686 patients, including 178 octogenarians (26%), were followed for 38 ± 22 months. Octogenarians exhibited a similar change in NYHA functional class (P = .640), left ventricular ejection fraction increase (P = .796), and decrease in end-diastolic (P = .441) and end-systolic (P = .312) diameter compared with their younger counterparts undergoing CRT. Octogenarians had a higher all-cause mortality risk (P < .001), but heart failure readmission risk did not differ (hazard ratio 0.916, 95% confidence interval 0.638-1.313; P = .632). A higher proportion of noncardiac deaths was observed in octogenarians (74%) versus younger patients (50%; P = .022), with worsening heart failure rather than malignant tachyarrhythmia being the main cardiac cause of death. Compared with an age-matched sample from the general population, octogenarians receiving CRT had an equivalent annual mortality rate (log-rank test: P = .444).

CONCLUSIONS

Octogenarians retain the ability to mount a significant symptomatic and ventricular remodeling response after CRT, resulting in survival similar to the general age-matched population.

What is the cost of non-response to cardiac resynchronization therapy? Hospitalizations and healthcare utilization in the CRT-D population

BACKGROUND

Cardiac resynchronization therapy (CRT) is an effective treatment for heart failure (HF) with left ventricular systolic dysfunction and prolonged QRS interval. However, one third of patients do not benefit from treatment. This study compares the heart failure hospitalization (HFH) rates and corresponding costs between responders and non-responders to CRT.

METHODS

At a single center in New Jersey, we enrolled patients with de novo CRT-D implants between January 2011 and July 2013. Medical history at implant and all subsequent hospitalizations were collected. A retrospective chart review of the cardiology visit at or closest to 12 months post-CRT implant was performed, and patients were classified into responders and non-responders. Universal billing records (UB-04), ICD-9-CM diagnoses, and procedure codes were used to determine whether each hospitalization was due to HF. For each heart failure hospitalization (HFH), an MS-DRG-based US national average Medicare reimbursement was determined. HFH rates and associated payor costs were compared between responders and non-responders using negative binomial regression and non-parametric bootstrapping (×10,000), respectively.

RESULTS

CRT response was determined in 135 patients (n = 103 responders, n = 32 non-responders, average follow-up 1.4 years). Demographics, pre-implant HF characteristics, NYHA Class, QRS duration, ejection fraction (EF), left bundle branch block (LBBB) status, and co-morbidities were not statistically different between the two groups. The HFH rate was significantly lower in responders (0.43/patient year) compared to non-responders (0.96/patient year, IRR = 0.45, 95 % CI (0.23 0.90), P = 0.0197). Average US national Medicare reimbursement for the responder group (US$7205/patient year) was 48 % lower than that for the non-responder group (US$13,861/patient year, P = 0.035).

CONCLUSION

In this single-center retrospective study, responders to CRT had significantly lower rates of post-implant heart failure hospitalization rate and reduced associated payor costs compared to non-responders. Therapies that increase CRT response rates can substantially reduce healthcare utilization.

Comparison between a count-based and geometrical approach for the assessment of left ventricular dyssynchrony using myocardial perfusion scintigraphy

OBJECTIVE

There are two distinct approaches for the assessment of left ventricular (LV) dyssynchrony by myocardial perfusion scintigraphy (MPS). The aim of this study was to compare the performance of the count-based and geometrical approach in clinical data using gated single photon emission computed tomography MPS.

MATERIAL AND METHODS

Group 1 consisted of 113 patients (49 men, 64 women) with normal perfusion [summed rest score (SRS)≤3], normal LV ejection fraction (≥55%), and normal QRS duration (QRSd<120 ms). Group 2 consisted of 89 heart failure patients (79 men, 10 women) with no restriction for SRS, LV ejection fraction ≤35%, and QRSd ≥120 ms. All MPS parameters were obtained from the software Corridor4DM. Dyssynchrony parameters used were time to peak contraction, SD, and bandwidth (BW).

RESULTS

SD and BW were estimated higher (difference group 1: SD 3.0±2.3 and BW 11.3±9.3, P-values <0.001; difference group 2: SD 2.4±4.3 and BW 1.3±17.0, P-value <0.001 and 0.479 respectively) using the count-based approach in comparison with the geometrical method. A significant and good correlation was found between these two methods (R=0.763, 0.902, 0.896 for time to peak contraction, SD, and BW respectively, P-values ≤0.001). SD and BW in both approaches were equally good parameters for differentiating heart failure patients (area under the curve: 0.995-0.998), although using different cut-off values.

CONCLUSION

The count-based approach generally provides a wider phase distribution and subsequently greater SD and BW estimates compared with the geometrical algorithm. These differences result in clinically relevant deviations in normal and cut-off values that have to be recognized when evaluating patients.

Do we need to monitor the percentage of biventricular pacing day by day?

BACKGROUND

Incidence and clinical significance of transient, daily fluctuations of biventricular pacing percentage (CRT%) remain unknown. We assessed the value of daily remote monitoring in identifying prognostically critical burden of low CRT%.

METHODS AND RESULTS

Prospective, single-centre registry encompassed 304 consecutive heart failure patients with cardiac resynchronization therapy defibrillators (CRT-D). Patients with 24-h episodes of CRT% loss<95% were assigned to quartiles depending on cumulative time spent in low CRT%: quartile 1 (1-8days), 2 (9-20days), 3 (21-60days) and quartile 4 (>60days). During median follow-up of 35months 51,826 transmissions were analysed, including 15,029 in 208 (68.4%) patients with episodes of low CRT%. Overall, mean CRT%≥95% vs. <95% resulted in a 4-fold lower mortality (17.3 vs. 68.2%; p<0.001). Fifty-four percent of patients experienced episodes of CRT% loss, despite 85.6% having mean CRT%≥95%. Mortality was lowest in quartile 1 (7.7%), while longer periods of CRT% loss resulted in significantly higher death rates (25.0 vs. 34.6 vs. 57.7%; quartiles 2-4 respectively, p<0.001), despite mean CRT% still being ≥95% in quartiles 1-3. Cumulative low CRT% burden was the independent risk factor for death (HR 1.013; 95% CI 1.006-1.021; p<0.001). Mortality rose by 1.3 and 49% with every additional day and quartile of CRT% loss, respectively.

CONCLUSIONS

Daily remote monitoring allows one to detect 24-h episodes of CRT% loss<95% in over two-thirds of CRT-D recipients during median observation of 3years. Cumulative low CRT% burden (in days) independently predicts mortality before mean CRT% drop.

Safety and Cost-Effectiveness of Same-Day Cardiac Resynchronization Therapy and Implantable Cardioverter Defibrillator Implantation

Cardiac resynchronization therapy (CRT) and implantable cardioverter defibrillator (ICD) implantation improve morbidity and mortality in selected patients. Many centers still admit patients overnight. We evaluated the safety, feasibility, and cost savings of same-day CRT/ICD device implantation by performing a retrospective study of all consecutive elective CRT/ICD implants at a tertiary center from January 2009 to April 2013. All emergency and/or inpatient cases were excluded. Data were collected on baseline demographics, implantation indication, procedure details, complications (categorized as immediate [≤24 hours], short term [24 hours to 6 weeks], medium term [6 weeks to 4 months], and long term [>4 months]), and mortality (30 day and 1 year). Comparisons were made between those having planned same-day versus overnight stay procedures. A cost analysis was performed to evaluate cost savings of the same-day policy. A total of 491 devices were implanted during this period: 267 were elective (54 planned overnight, 213 planned same-day) of which 229 were CRT pacemakers or CRT defibrillators and 38 ICDs. There were 26 total overall complications (9.7%) with no significant differences between planned same-day versus planned overnight stay cohorts (9.4% vs 11.1%, p = 0.8) and specifically no differences in immediate, short-, medium-, and long-term complications at follow-up. The 30-day and 1-year mortality rates did not differ between the two groups. An overnight stay at our hospital costs $450 (£300); our cost saving during this period was $91,800 (£61,200). Same-day CRT/ICD implantation is safe, feasible, and associated with significant cost savings. It provides significant advantages for patients and health care providers, especially given the current financial climate.

Ventricular pacing - Electromechanical consequences and valvular function

Although great strides have been made in the areas of ventricular pacing, it is still appreciated that dyssynchrony can be malignant, and that appropriately placed pacing leads may ameliorate mechanical dyssynchrony. However, the unknowns at present include: 1. The mechanisms by which ventricular pacing itself can induce dyssynchrony; 2. Whether or not various pacing locations can decrease the deleterious effects caused by ventricular pacing; 3. The impact of novel methods of pacing, such as atrioventricular septal, lead-less, and far-field surface stimulation; 4. The utility of ECG and echocardiography in predicting response to therapy and/or development of dyssynchrony in the setting of cardiac resynchronization therapy (CRT) lead placement; 5. The impact of ventricular pacing-induced dyssynchrony on valvular function, and how lead position correlates to potential improvement. This review examines the existing literature to put these issues into context, to provide a basis for understanding how electrical, mechanical, and functional aspects of the heart can be distorted with ventricular pacing. We highlight the central role of the mitral valve and its function as it relates to pacing strategies, especially in the setting of CRT. We also provide future directions for improved pacing modalities via alternative pacing sites and speculate over mechanisms on how lead position may affect the critical function of the mitral valve and thus overall efficacy of CRT.

Developments in Cardiac Resynchronisation Therapy

Cardiac resynchronisation therapy (CRT) is an important therapy for patients with heart failure with a reduced ejection fraction and interventricular conduction delay. Large trials have established the role of CRT in reducing heart failure hospitalisations and improving symptoms, left ventricular (LV) function and mortality. Guidelines from major medical societies are consistent in support of CRT for patients with New York Health Association (NYHA) class II, III and ambulatory class IV heart failure, reduced LV ejection fraction and QRS prolongation, particularly left bundle branch block. The current challenge facing practitioners is to maximise the rate of patients who respond to CRT and the magnitude of that response. Current areas of interest for achieving these goals include tailoring patient selection, individualising LV lead placement and application of new technologies and techniques for CRT delivery.

Comparison of right ventricular septal pacing and right ventricular apical pacing in patients receiving cardiac resynchronization therapy defibrillators: the SEPTAL CRT Study

AIMS

Cardiac resynchronization therapy (CRT) is a recommended treatment of heart failure (HF) patients with depressed left ventricular ejection fraction and wide QRS. The optimal right ventricular (RV) lead position being a matter of debate, we sought to examine whether RV septal (RVS) pacing was not inferior to RV apical (RVA) pacing on left ventricular reverse remodelling in patients receiving a CRT-defibrillator.

METHODS AND RESULTS

Patients (n = 263, age = 63.4 ± 9.5 years) were randomly assigned in a 1:1 ratio to RVS (n = 131) vs. RVA (n = 132) pacing. Left ventricular end-systolic volume (LVESV) reduction between baseline and 6 months was not different between the two groups (-25.3 ± 39.4 mL in RVS group vs. -29.3 ± 44.5 mL in RVA group, P = 0.79). Right ventricular septal pacing was not non-inferior (primary endpoint) to RVA pacing with regard to LVESV reduction (average difference = -4.06 mL; P = 0.006 with a -20 mL non-inferiority margin). The percentage of 'echo-responders' defined by LVESV reduction >15% between baseline and 6 months was similar in both groups (50%) with no difference in the time to first HF hospitalization or death (P = 0.532). Procedural or device-related serious adverse events occurred in 68 patients (RVS = 37) with no difference between the two groups (P = 0.401).

CONCLUSION

This study demonstrates that septal RV pacing in CRT is non-inferior to apical RV pacing for LV reverse remodelling at 6 months with no difference in the clinical outcome. No recommendation for optimal RV lead position can hence be drawn from this study.

CLINICALTRIALS GOV NUMBER

NCT 00833352.

[Device therapy of chronic heart failure: Update 2015]

Cardiac pacemakers, implantable cardioverter defibrillators (ICD) and systems for cardiac resynchronization therapy (CRT) represent an important component of heart failure therapy. Pacemakers only play a role in bradycardia-associated heart failure and require optimal programming to prevent ventricular desynchronization. Primary prophylactic ICD implantation is indicated in patients with a left ventricular ejection fraction of ≤ 35 %, clinical stages NYHA II-III and a life expectancy > 1 year. The CRT is indicated in patients with a left bundle branch block but only in individual cases for other QRS morphologies of < 150 ms duration. The combination of CRT with a pacemaker or defibrillator must be decided on an individual basis. Device therapy in heart failure should always include remote monitoring to detect events early and to implement treatment accordingly. New developments include quadripolar left ventricular leads and pacing from multiple sites simultaneously thus enabling better resynchronization. Stimulation for modulation of cardiac contractility and the autonomous nervous system are currently being clinically tested. The optimal utilization of device therapy improves the course of heart failure and prevents cardiac decompensation and fatalities.

Cardiac Resynchronization Therapy: An Overview on Guidelines

Cardiac resynchronization therapy (CRT) is included in international consensus guidelines as a treatment with proven efficacy in well-selected patients on top of optimal medical therapy. Although all the guidelines strongly recommend CRT for LBBB with QRS duration greater than 150 milliseconds, lower strength of recommendation is reported for QRS duration of 120 to 150 milliseconds, especially if not associated with LBBB. CRT is not recommended for a QRS of less than 120 milliseconds. No indication emerges for guiding the implant based on echocardiographic evaluation of dyssynchrony. Many data indicate that CRT is underused and there is heterogeneity in its implementation.

T-wave area as biomarker of clinical response to cardiac resynchronization therapy

AIMS

There is increasing evidence that left bundle branch block (LBBB) morphology on the electrocardiogram is a positive predictor for response to cardiac resynchronization therapy (CRT). We previously demonstrated that the vectorcardiography (VCG)-derived T-wave area predicts echocardiographic CRT response in LBBB patients. In the present study, we investigate whether the T-wave area also predicts long-term clinical outcome to CRT.

METHODS AND RESULTS

This is a retrospective study consisting of 335 CRT recipients. Primary endpoint were the composite of heart failure (HF) hospitalization, heart transplantation, left ventricular assist device implantation or death during a 3-year follow-up period. HF hospitalization and death alone were secondary endpoints. The patient subgroup with a large T-wave area and LBBB 36% reached the primary endpoint, which was considerably less (P < 0.01) than for patients with LBBB and a small T-wave area or non-LBBB patients with a small or large T-wave area (48, 57, and 51%, respectively). Similar differences were observed for the secondary endpoints, HF hospitalization (31 vs. 51, 51, and 38%, respectively, P < 0.01) and death (19 vs. 42, 34, and 42%, respectively, P < 0.01). In multivariate analysis, a large T-wave area and LBBB were the only independent predictors of the combined endpoint besides high creatinine levels and use of diuretics.

CONCLUSION

T-wave area may be useful as an additional biomarker to stratify CRT candidates and improve selection of those most likely to benefit from CRT. A large T-wave area may derive its predictive value from reflecting good intrinsic myocardial properties and a substrate for CRT.

Remote monitoring of implantable devices: Should we continue to ignore it?

The number of patients with implantable cardioverter defibrillators (ICDs) is increasing. In addition to improve survival, ICD can collect data related to device function and physiological parameters. Remote monitoring (RM) of these data allows early detection of technical or clinical problems and a prompt intervention (reprogramming device or therapy adjustment) before the patient require hospitalization. RM is not a substitute for emergency service and its consultation is now limited during working hours. Thus, a consent form is required to inform patients about benefits and limitations. The available studies indicate that remote monitoring is more effective than traditional calendar face to face based encounters. RM is safe, highly reliable, cost efficient, allows quick reply to failures, and reduces the number of scheduled visits and the incidence of inappropriate shocks with a positive impact on survival. It follows that RM has the credentials to be the standard of care for ICD management; however, unfortunately, there is a delay in physician acceptance and implementation. The recent observations from randomized IN-TIME study that showed a clear survival benefit with RM in heart failure patients have encouraged us to review both the negative and positive aspects of RM collected in a little more than a decade.

Delayed AICD therapy and cardiac arrest resulting from undersensing of ventricular fibrillation in a subject with hypertrophic cardiomyopathy-A case report

Defibrillation testing is no longer routinely performed after automatic implantable cardioverter-defibrillator (AICD) implantation. However, certain subjects undergoing AICD implantation may be at higher risk of undersensing of ventricular arrhythmias resulting in potentially fatal outcomes. We present the case of a 30-year-old woman with hypertrophic cardiomyopathy (HCM; ‘asymmetric septal hypertophy’ morphologic variant) and prophylactic AICD who experienced an out of hospital cardiac arrest. AICD interrogation revealed undersensing as a result of intermittent high amplitude electrograms during an episode of ventricular fibrillation (VF). The subject underwent replacement and repositioning of the AICD lead along with pulse generator replacement (that utilized a different VF sensing algorithm) with appropriate sensing of VF and successful defibrillation testing. The presence of intermittent high amplitude electrograms during episodes of VF in AICDs using the AGC function should be recognized as a situation that may necessitate interventions to prevent undersensing and consequent delay in therapy.

Feasibility of a novel atrioventricular delay optimization method using transmitral and pulmonary venous flow in patients with sequential ventricular pacing or cardiac resynchronization therapy

Background

Although several echo-Doppler methods were proposed to optimize atrioventricular (AV) delay in patients with sequential ventricular pacing, “echo-guided” AV optimization has not been widely adopted clinically. A combination of trasmitral flow (TMF) and pulmonary venous flow (PVF) measurements may be beneficial to further optimize AV delay to achieve better cardiac function. The aim of this study was to assess the feasibility and usefulness of AV delay optimization by combined use of TMF and PVF.

Methods

A total of 32 patients after sequential ventricular pacemaker implantation were enrolled and studied. The optimal AV delay was defined as the timing to minimize the duration between PVF reversal (a) wave and the duration of the “A” wave of TMF. Stroke volume was measured at the “optimized” AV delay (AVD_OPT) and was compared with that obtained at shorter (AVD_OPT − 50 ms) and longer (AVD_OPT + 50 ms) AV delays.

Results

AV optimization was feasible in 27 of 32 patients (87 %). Stroke volume at AVD_OPT was significantly higher than that at shorter or longer AV delay (63 ± 18 ml vs. 57 ± 15 ml vs. 56 ± 16 ml, P = 0.001).

Conclusions

AV delay optimization using TMF and PV flow was feasible. Usefulness of this method requires further investigation with a larger study population.

The ratio of the neutrophil leucocytes to the lymphocytes predicts the outcome after cardiac resynchronization therapy

Aims

The low lymphocyte counts and high neutrophil leucocyte fractions have been associated with poor prognosis in chronic heart failure. We hypothesized that the baseline ratio of the neutrophil leucocytes to the lymphocytes (NL ratio) would predict the outcome of chronic heart failure patients undergoing cardiac resynchronization therapy (CRT).

Methods and results

The qualitative blood counts and the serum levels of N-terminal of the prohormone brain natriuretic peptide (NT-proBNP) of 122 chronic heart failure patients and 122 healthy controls were analysed prospectively in this observational study. The 2-year mortality was considered as primary endpoint and the 6-month reverse remodelling (≥15% decrease in the end-systolic volume) as secondary endpoint. Multivariable regression analyses were applied and net reclassification improvement (NRI) and integrated discrimination improvement (IDI) were calculated. The NL ratio was elevated in chronic heart failure patients when compared with the healthy controls [2.93 (2.12–4.05) vs. 2.21 (1.64–2.81), P < 0.0001]. The baseline NL ratio exceeding 2.95 predicted the lack of the 6-month reverse remodelling [n = 63, odds ratio = 0.38 (0.17–0.85), P = 0.01; NRI = 0.49 (0.14–0.83), P = 0.005; IDI = 0.04 (0.00–0.07), P = 0.02] and the 2-year mortality [n = 29, hazard ratio = 2.44 (1.04–5.71), P = 0.03; NRI = 0.63 (0.24–1.01), P = 0.001; IDI = 0.04 (0.00–0.08), P = 0.02] independently of the NT-proBNP levels or other factors.

Conclusion

The NL ratio is elevated in chronic heart failure and predicts outcome after CRT. According to the reclassification analysis, 4% of the patients would have been better categorized in the prediction models by combining the NT-proBNP with the NL ratio. Thus, a single blood count measurement could facilitate the optimal patient selection for the CRT.