Long-term reverse remodeling with cardiac resynchronization therapy: results of extended echocardiographic follow-up

Current role of Conduction System Pacing in Patients Requiring Permanent Pacing

His bundle pacing (HBP) and left bundle branch pacing (LBBP) are novel methods of pacing directly pacing the cardiac conduction system. HBP while developed more than two decades ago, only recently moved into the clinical mainstream. In contrast to conventional cardiac pacing, conduction system pacing including HBP and LBBP utilizes the native electrical system of the heart to rapidly disseminate the electrical impulse and generate a more synchronous ventricular contraction. Widespread adoption of conduction system pacing has resulted in a wealth of observational data, registries, and some early randomized controlled clinical trials. While much remains to be learned about conduction system pacing and its role in electrophysiology, data available thus far is very promising. In this review of conduction system pacing, the authors review the emergence of conduction system pacing and its contemporary role in patients requiring permanent cardiac pacing.

The complete reversal effect following angiotensin-converting enzyme inhibitors or angiotensin receptor blockers and beta-blockers after the primary diagnosis of dilated cardiomyopathy

Background

Whether combination administration of angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), and beta-blockers (BBs) has a "reversal" effect on cardiac structure and function for first-diagnosed idiopathic dilated cardiomyopathy (FSIDCM) patients with unclear etiologies and inducements is unknown.

Materials and Methods

We studied the effect of the protocol on FSIDCM patients. The effect was investigated in 26 FSIDCM patients. The criteria of "complete reversal" included left ventricular end-diastolic diameter (LVEDD) ≤50 mm for females or ≤55 mm for males and left ventricular ejection fraction (LVEF) ≥45%; the criteria of "partial reversal" was the decreased rate of LVEDD (ΔLVEDD) >10% or the increase rate of LVEF (ΔLVEF) >10%; the criteria of "no reversal" included LVEDD >50 mm for females or >55 mm for males and ΔLVEDD <10%, and LVEF <45% and ΔLVEF <10%.

Results

Within the follow-up period, nine patients showed "complete reversal," eight "partial reversal," and nine "no reversal." Improvements in echocardiogram parameters were the most significant in "complete reversal" patients (P < 0.001), followed by "partial reversal" and "no reversal" patients (P < 0.05). The QRS (Q wave, R wave, S wave) duration and symptoms duration in "complete reversal" patients were the shortest, followed by "partial reversal" and "no reversal" patients.

Conclusion

ACEIs or ARBs and BBs have a "complete reversal" effect on the left ventricular size and function of some FSIDCM patients. Patients with a narrow QRS and short symptom duration may have a good response.

Transcatheter left ventriculoplasty

Despite significant advances in pharmacological, electrophysiological and valve therapies for heart failure with reduced ejection fraction (HFrEF), the associated morbidity, mortality and healthcare costs remain high. With a constantly growing heart failure population, the existing treatment gap between current and advanced heart failure therapies (e.g., left ventricular [LV] assist devices, heart transplantation) reflects a large unmet need, calling for novel therapeutic approaches. Left ventricular remodelling and dilatation, with or without scar formation, is the hallmark of cardiomyopathy and is associated with poor prognosis. In the era of exciting advances in structural heart interventions, the advent of minimally invasive, device-based therapies directly targeting the LV geometry and promoting physical reverse remodelling has created a new frontier in the battle against heart failure. Interventional heart failure therapy is a rapidly emerging field, encompassing structural heart and minimally invasive hybrid procedures, with two left ventriculoplasty devices currently under investigation in pivotal clinical trials in the US. This review addresses the rationale for left ventriculoplasty, presents the prior surgical and percutaneous attempts in the field, provides an overview of the novel transcatheter left ventriculoplasty devices and their respective trials, and highlights potential challenges associated with establishing such device-based therapies in our armamentarium against heart failure.

The Value of Left Ventricular Mechanical Dyssynchrony and Scar Burden in the Combined Assessment of Factors Associated with Cardiac Resynchronization Therapy Response in Patients with CRT-D

Background: Cardiac resynchronization therapy (CRT) improves the outcome in patients with heart failure (HF). However, approximately 30% of patients are nonresponsive to CRT. The aim of this study was to determine the role of the left ventricular (LV) mechanical dyssynchrony (MD) and scar burden as predictors of CRT response. Methods: In this study, we included 56 patients with HF and the left bundle-branch block with QRS duration ≥ 150 ms who underwent CRT-D implantation. In addition to a full examination, myocardial perfusion imaging and gated blood-pool single-photon emission computed tomography were performed. Patients were grouped based on the response to CRT assessed via echocardiography (decrease in LV end-systolic volume ≥15% or/and improvement in the LV ejection fraction ≥5%). Results: In total, 45 patients (80.3%) were responders and 11 (19.7%) were nonresponders to CRT. In multivariate logistic regression, LV anterior-wall standard deviation (adjusted odds ratio (OR) 1.5275; 95% confidence interval (CI) 1.1472–2.0340; p = 0.0037), summed rest score (OR 0.7299; 95% CI 0.5627–0.9469; p = 0.0178), and HF nonischemic etiology (OR 20.1425; 95% CI 1.2719–318.9961; p = 0.0331) were the independent predictors of CRT response. Conclusion: Scar burden and MD assessed using cardiac scintigraphy are associated with response to CRT.

Cardiac pericyte reprogramming by MEK inhibition promotes arteriologenesis and angiogenesis of the ischemic heart

Pericytes (PCs) are abundant yet remain the most enigmatic and ill-defined cell population in the heart. Here, we investigated whether PCs can be reprogrammed to aid neovascularization. Primary PCs from human and mouse hearts acquired cytoskeletal proteins typical of vascular smooth muscle cells (VSMCs) upon exclusion of EGF/bFGF, which signal through ERK1/2, or upon exposure to the MEK inhibitor PD0325901. Differentiated PCs became more proangiogenic, more responsive to vasoactive agents, and insensitive to chemoattractants. RNA sequencing revealed transcripts marking the PD0325901-induced transition into proangiogenic, stationary VSMC-like cells, including the unique expression of 2 angiogenesis-related markers, aquaporin 1 (AQP1) and cellular retinoic acid-binding protein 2 (CRABP2), which were further verified at the protein level. This enabled us to trace PCs during in vivo studies. In mice, implantation of Matrigel plugs containing human PCs plus PD0325901 promoted the formation of αSMA+ neovessels compared with PC only. Two-week oral administration of PD0325901 to mice increased the heart arteriolar density, total vascular area, arteriole coverage by PDGFRβ+AQP1+CRABP2+ PCs, and myocardial perfusion. Short-duration PD0325901 treatment of mice after myocardial infarction enhanced the peri-infarct vascularization, reduced the scar, and improved systolic function. In conclusion, myocardial PCs have intrinsic plasticity that can be pharmacologically modulated to promote reparative vascularization of the ischemic heart.

Left ventricular reverse remodelling and its predictors in non-ischaemic cardiomyopathy

Adverse remodelling following an initial insult is the hallmark of heart failure (HF) development and progression. It is manifested as changes in size, shape, and function of the myocardium. While cardiac remodelling may be compensatory in the short term, further neurohumoral activation and haemodynamic overload drive this deleterious process that is associated with impaired prognosis. However, in some patients, the changes may be reversed. Left ventricular reverse remodelling (LVRR) is characterized as a decrease in chamber volume and normalization of shape associated with improvement in both systolic and diastolic function. LVRR might occur spontaneously or more often in response to therapeutic interventions that either remove the initial stressor or alleviate some of the mechanisms that contribute to further deterioration of the failing heart. Although the process of LVRR in patients with new‐onset HF may take up to 2 years after initiating treatment, there is a significant portion of patients who do not improve despite optimal therapy, which has serious clinical implications when considering treatment escalation towards more aggressive options. On the contrary, in patients that achieve delayed improvement in cardiac function and architecture, waiting might avoid untimely implantable cardioverter‐defibrillator implantation. Therefore, prognostication of successful LVRR based on clinical, imaging, and biomarker predictors is of utmost importance. LVRR has a positive impact on prognosis. However, reverse remodelled hearts continue to have abnormal features. In fact, most of the molecular, cellular, interstitial, and genome expression abnormalities remain and a susceptibility to dysfunction redevelopment under biomechanical stress persists in most patients. Hence, a distinction should be made between reverse remodelling and true myocardial recovery. In this comprehensive review, current evidence on LVRR, its predictors, and implications on prognostication, with a specific focus on HF patients with non‐ischaemic cardiomyopathy, as well as on novel drugs, is presented.

Long-Term Performance Comparison of Bipolar Active vs. Quadripolar Passive Fixation Leads in Cardiac Resynchronisation Therapy

Background: Bipolar active fixation (BipolarAFL) and quadripolar passive fixation left-ventricular leads (QuadPFL) have been designed to reduce the risk of phrenic nerve stimulation (PNS), enable targeted left-ventricular pacing, and overcome problems of difficult coronary venous anatomy and lead dislodgment. This study sought to report the long-term safety and performance of a BipolarAFL, Medtronic Attain Stability 20066, compared to QuadPFL. Methods: We performed a single-operator retrospective analysis of 81 patients receiving cardiac resynchronization therapy (CRT) (36 BipolarAFL, 45 QuadPFL). Immediate implant data and electrical and clinical data during follow-up (FU) were analyzed. Results: BipolarAFL has been chosen in patients with significantly larger estimated vein diameter (at the lead tip: 7.2 ± 4.1 Fr vs. 4.1 ± 2.3 Fr, p < 0.001) without significant time difference until the final lead position was achieved (BipolarAFL: 20.9 ± 10.5 min, vs. QuadPFL: 18.9 ± 8.9 min, p = 0.35). At 12 month FU no difference in response rate to CRT was recorded between BipolarAFL and QuadPFL according to left ventricular end-systolic volume (61.1 vs. 60.0%, p = 0.82) and New York Heart Association (66.7 vs. 62.2%, p = 0.32). At median FU of 48 months (IQR: 44-54), no lead dislodgment occurred in both groups but a significantly higher proportion of PNS was recorded in QuadPFL (13 vs. 0%, p < 0.05). Electrical parameters were stable during FU in both groups without significant differences. Conclusion: BipolarAFL can be implanted with ease in challenging coronary venous anatomy, shows excellent electrical performance and no difference in clinical outcome compared to QuadPFL.

Prognostic predictors and echocardiographic time course after device replacement in patients treated chronically with cardiac resynchronization therapy devices

The prognostic predictors of death or heart failure hospitalization and the echocardiographic response after initial cardiac resynchronization therapy (CRT) device replacement (CRT-r) remain unclear. We evaluated the predictors and the echocardiographic time course in patients after CRT-r. Consecutive 60 patients underwent CRT-r because of battery depletion. Patients were divided into two groups depending on the chronic echocardiographic response to CRT (left ventricular end-systolic volume [LVESV] reduction of ≥ 15%) at the time of CRT-r: CRT responders (group A; 35 patients) and CRT nonresponders (group B; 25 patients). The primary endpoint was a composite of death from any cause or heart failure hospitalization. Changes in LVESV and left ventricular ejection fraction (LVEF) after CRT-r were also analyzed. During the mean follow-up of 46 ± 33 months after CRT-r, the primary endpoint occurred more frequently in group B (group A versus group B; 8/35 [23%] patients versus 19/25 [76%] patients, p < 0.001). No significant changes in LVESV and LVEF were observed at the mean of 46 ± 29 months after CRT-r in both groups. A multivariate analysis identified echocardiographic nonresponse to CRT, chronic kidney disease, atrial fibrillation, and New York Heart Association functional class III or IV at the time of CRT-r as independent predictors of the primary endpoint in all patients. Residual echocardiographic nonresponse, comorbidities, and heart failure symptoms at the time of CRT-r predict the subsequent very long-term prognosis after CRT-r. No further echocardiographic response to CRT was found after CRT-r.

Long-term cardiac reverse remodeling after cardiac resynchronization therapy

INTRODUCTION

The benefit of cardiac resynchronization therapy (CRT) in heart failure (HF) patients with reduced left ventricular ejection fraction (LVEF) have been observed in the first year. However, there are few data on long-term follow-up and the effect of changes of LVEF on mortality. This study aimed to assess the LV remodeling after CRT implantation and the probable effect of changes in LVEF with repeated measures on mortality over time in a real-world registry.

METHODS

Among our cohort of 328 consecutive CRT patients, mixed model effect analysis have been made to describe the temporal evolution of LVEF and LVESV changes over time up with several explanatory variables. Besides, the effect of LVEF along time on the probability of mortality was evaluated using joint modeling for longitudinal and survival data.

RESULTS

The study population included 328 patients (253 men; 70.2 ± 9.5 years) in 4.2 (2.9) years follow-up. There was an increase in LVEF of 11% and a reduction in LVESV of 42 mL during the first year. These changes are more important during the first year, but slight changes remain during the follow-up. The largest reduction in LVESV occurred in patients with left bundle branch block (LBBB) and the smallest reduction in patients with NYHA IV. The smallest increase in LVEF was an ischemic etiology, longer QRS, and LV electrode in a nonlateral vein. Besides, the results showed that the LVEF profiles taken during follow-up after CRT were associated with changes in the risk of death.

CONCLUSION

Reverse remodeling of the left ventricle is observed especially during the first year, but it seems to be maintained later after CRT implantation in a contemporary cohort of patients. Longitudinal measurements could give us additional information at predicting the individual mortality risk after adjusting by age and sex compared to a single LVEF measurement after CRT.

Left Ventricular Ejection Fraction 1 Year After Acute Myocardial Infarction Identifies the Benefits of the Long-Term Use of β-Blockers: Analysis of Data From the KAMIR-NIH Registry

[Figure: see text].

Upgrading to cardiac resynchronisation therapy: Concordance of real-world experience with clinical guidelines

Objective

Revision to cardiac resynchronisation therapy (CRT) in patients with existing pacemakers with worsening heart failure (HF) can improve symptoms and cardiac function. We identify factors that predict improvement in left ventricular ejection fraction (LVEF) within a year of CRT revision.

Methods

We performed a retrospective study of 146 consecutive patients (16% female, mean age 73 ± 11 years, mean LVEF 27 ± 8%) undergoing revision to CRT (January 2012 to May 2018) in a single tertiary centre. LVEF was measured pre-revision and 3, 6 and 12 months post-upgrade.

Results

At 6 months, 68% of patients demonstrated improvement in LVEF (mean ΔLVEF + 6.7% ± 9.6). Compared to patients in atrial fibrillation (AF), patients with sinus rhythm had a greater improvement in LVEF at 6 months (sinus 8.4 ± 10.3% vs. AF 4.2 ± 8.0%, p = 0.02). Compared to ischaemic cardiomyopathy (ICM), patients with non-ischaemic cardiomyopathy (NICM) had a greater improvement in LVEF at 6 months (NICM 8.4 ± 9.8% vs ICM 4.8 ± 9.2%, p = 0.05). Patients with RV pacing ≥40% at baseline had a greater improvement in LVEF at 6 months (≥40% RV pacing 9.3 ± 10.2 vs. < 40% RV pacing 4.0 ± 7.4%, p = 0.01). All improvements were sustained over 12 months post-revision. There was no significant difference between genders, years between initial implant and revision, or previous device type.

Conclusions

Our real-world experience supports current guidelines on CRT revision. NICM, ≥40% RV pacing and sinus rhythm are the main predictors of improvement in LVEF in patients who underwent CRT revision.

The therapeutic effects of upgrade to cardiac resynchronization therapy in pacing-induced cardiomyopathy or chronic right ventricular pacing patients: a meta-analysis

Pacing-induced cardiomyopathy (PICM) or heart failure accompanied with chronic right ventricular pacing (CRVP-HF) has no established treatments. We aimed to carry out a meta-analysis of published studies about the therapeutic effects of the upgrade to cardiac resynchronization therapy (CRT) in patients of PICM/CRVP-HF. The PUBMED, EMBASE, MEDLINE, OVID databases, and Cochrane Library were systemically searched for relevant publications. Data about the improvements of left ventricular ejection fraction (LVEF), NYHA functional class (NYHA-FC), and the CRT response rate was extracted and synthesized. Mean difference (MD), odds ratio, and standard mean difference (SMD) with 95% confidence interval (CI) were calculated as the effect size by both fixed and random effect models. We included sixteen studies (four about PICM and twelve about CRVP-HF). The total sample size of PICM/CRVP-HF patients was 924. Upgrade to CRT improved the LVEF by 10.87% (95%CI, 8.90 to 12.84%) and reduce the NYHA-FC by around one class (MD, -1.25; 95%CI, -1.43 to -1.06) in PICM/CRVP-HF patients overall. Upgrade to CRT seemed to improve LVEF no less than de-novo CRT (SMD 0.24; 95%CI 0.05 to 0.43; P < 0.05). This meta-analysis suggested that upgrade CRT could improve the cardiac function in PICM/CRVP-HF patients. This strategy may be considered in these patients but require more evidence about the efficacy and procedure-related complications from prospective studies or randomized controlled trials.

Prognostic effects of longitudinal changes in left ventricular ejection fraction with cardiac resynchronization therapy

Aims

Left ventricular ejection fraction (LVEF) is considered an indicator of cardiac resynchronization therapy (CRT). Longitudinal studies on the predictive value of LVEF are scarce. We aimed to comprehensively evaluate the prognostic role of LVEF in the outcomes of Chinese patients with CRT.

Methods and results

Three hundred ninety‐two patients were divided into three tertiles of LVEF: ≤25%, 25–30%, and 30–35%, and four groups by LVEF changes: <0% (negative response); ≥0% and ≤5% (non‐response); >5% and ≤15% (response); and >15% (super‐response). One hundred six patients were super‐responders. During a median follow‐up of 3.6 years, 141 reached the composite endpoint. Odds ratios (ORs) for super‐response depicted a reversed U‐shaped relationship for baseline LVEF with a peak at 25–30%. Independent predictors of super‐response were smaller left atrial diameter [odds ratio 0.897, 95% confidence interval (CI) 0.844–0.955, P = 0.001], smaller left ventricular end‐diastolic diameter (OR 0.937, 95% CI 0.889–0.989, P = 0.018), and higher estimated glomerular filtration rate (OR 1.018, 95% CI 1.001–1.035, P = 0.042) in Tertile 1; atrial fibrillation (OR 0.278, 95% CI 0.086–0.901, P = 0.033), left bundle branch block (OR 4.096, 95% CI 1.046–16.037, P = 0.043), and left ventricular end‐diastolic diameter (OR 0.929, 95% CI 0.876–0.986, P = 0.016) in Tertile 2; while female sex (OR 2.778, 95% CI 1.082–7.132, P = 0.034) and higher systolic blood pressure (OR 1.045, 95% CI 1.013–1.079, P = 0.006) in Tertile 3. An inverse association with the composite endpoint was found in Tertile 1 vs. Tertile 2 (hazard ratio 1.934, 95% CI 1.248–2.996, P = 0.003). The prognostic effects of CRT response in Tertile 3 and Tertile 1 varied significantly (P for trend = 0.017 and <0.001). Among three tertiles in super‐responders, event‐free survival was similar (P for trend = 0.143).

Conclusions

Left ventricular ejection fraction of 25–30% is associated with a better prognosis of super‐response. Predictors of super‐response are different for LVEF tertiles. CRT responses would have better prognostic performance than LVEF tertiles at baseline, which should be considered when clinicians screening eligible patients for CRT.

Autonomic regulation device therapy in heart failure with reduced ejection fraction: a systematic review and meta-analysis of randomized controlled trials

Heart failure with reduced ejection fraction (HFrEF) represents a significant public health burden associated with incremental health care costs. Given the limitations associated with pharmacological autonomic regulation therapy (ART), device-based autonomic neuromodulation is on the horizon now for ART in those patients. This systematic review aimed primarily to determine the effect of ART by devices on functional status and quality of life (QOL) in patients with HFrEF. We performed a meta-analysis of five randomized controlled trials (1074 patients) comparing ART by devices versus optimal medical therapy (OMT) in HFrEF. We assessed pooled estimates of odds ratio (OR) for improvement in New York Heart Association (NYHA) class and mean differences (MD) in 6-minute hall walk distance (6-MHWD), Minnesota Living with Heart Failure Questionnaire (MLHFQ) score, N-terminal pro b-type natriuretic peptide (NT-proBNP) levels, and left ventricular end-systolic volume index (LVESVi) with their 95% confidence intervals (CIs) at 6-month follow-up. Compared to OMT alone, ART by devices in HFrEF significantly improves NYHA class (OR 2.26, 95% CI 1.33 to 3.83, P = 0.003), increases 6-MHWD (MD 45.53 m, 95% CI 30.61 to 60.45, P < 0.00001), improves MLHFQ score (MD - 10.59, 95% CI - 20.62 to - 0.57, P = 0.04) with neutral effect on NT-proBNP levels (MD - 236.5 pg/ml, 95% CI - 523.86 to 50.87, P = 0.11) and LVESVi (MD - 1.01 ml/m², 95% CI - 4.49 to 2.47, P = 0.57). We concluded that device-based neuromodulation therapy significantly improves functional status and quality of life in patients with HFrEF.

Predictors of left ventricular reverse remodeling after percutaneous therapy for mitral regurgitation with the MitraClip system

OBJECTIVES

To investigate the predictors and clinical impact of left ventricular reverse remodeling (LVRR) after MitraClip (MC) therapy for degenerative (DMR) and functional mitral regurgitation (FMR).

BACKGROUND

MC therapy induces LVRR in patients with mitral regurgitation (MR) at high-risk for surgery. However, specific data on predictors of LVRR therapy are limited.

METHODS

This study included 164 patients treated by MC implantation with complete clinical and echocardiographic evaluation at baseline, 6 months, and 12 months. LVRR was defined as a decrease of ≥10% of the left ventricular end-diastolic diameter after 12 months and was found in 49% of the patients.

RESULTS

LVRR was associated with significantly reduced event rate 2 years after MC procedure. In the total cohort, multivariate regression analysis determined severe recurrent/residual MR after 12 months (p = .010, odds ratio [OR] = 0.26), male gender (p = .050, OR = 0.49) and left ventricular ejection fraction (LVEF) <20% (p = .046, OR = 0.24) as predictors of absence of LVRR. In the subgroup analysis according to etiology of MR, multivariate regression analysis revealed severe recurrent/residual MR after 12 months (p = .04, OR = 0.184) to inversely predict LVRR only in the DMR subgroup. In FMR, residual severe tricuspid regurgitation (TR) inversely predicts LVRR (p = .032, OR = 0.361).

CONCLUSIONS

LVRR occurs in half of the patients after MC and is associated with reduced MACCE rates at follow-up. Combined information on residual/recurrent MR, baseline LVEF and gender predict LVRR after MC procedure. While residual/recurrent MR is the independent predictor for the absence of LVRR in DMR, in FMR only severe residual TR independently predict LVRR.

Does 'super-responder' patients to cardiac resynchronization therapy still have indications for neuro-hormonal antagonists? Evidence from long-term follow-up in a single center

Background

Whether cardiac resynchronization therapy super-responders (CRT-SRs) still have indications for neuro-hormonal antagonists or not remains uninvestigated.

Methods

We reviewed clinical data from 376 patients who underwent CRT implantation in Fuwai Hospital from 2009 to 2015 and followed up to 2017. CRT-SRs were defined by an improvement of the New York Heart Association functional class and left ventricular ejection fraction to ≥ 50% in absolute values at 6-month follow-up. All CRT-SRs were assigned into two groups on the basis of whether persistently receiving neuro-hormonal antagonists (NHA) (defined as angiotensin-converting enzyme inhibitors/angiotensin receptor blockers and β-blockers) after 6-month follow-up and then we compared long-term outcome.

Results

A total of 60 patients met criteria for super-response. One of thirteen (7.7%) CRT-SRs without NHA had all-cause death, which also occurred in 2 of 47 (4.3%) in CRT-SRs with NHA (P = 0.526). However, 3 of 13 (23.1%) CRT-SRs without NHA had heart failure (HF) hospitalization, 1 of 47 (2.1%) CRT-SRs with NHA had this endpoint (P = 0.040). Besides, subgroup analysis indicated that, for ischemic etiology group, CRT-SRs receiving NHA had considerably lower incidence of HF hospitalization than those without NHA (0 vs. 75%, P = 0.014), which was not observed in non-ischemic etiology group (2.6% vs. 0, P = 1.000) during long-term follow-up.

Conclusions

Our study found that for ischemic etiology, compared with CRT-SRs with NHA, CRT-SRs without NHA were associated with a higher risk of HF hospitalization. However, for non-ischemic etiology, we found that CRT-SRs with NHA or without NHA at follow-up were associated with similar outcomes, which needed further investigation by prospective trials.

Effect of Exercise Training in Heart Failure Patients Without Echocardiographic Response to Cardiac Resynchronization Therapy

Background: Cardiac resynchronization therapy (CRT) is an effective treatment of heart failure (HF) with ventricular dyssynchrony, but not all patients respond to a similar extent. We investigated the efficacy and safety of exercise training (ET) in patients without response to CRT.

Methods and Results: Thirty-four patients who participated in a 3-month ET program and underwent cardiopulmonary exercise testing at baseline and after the program were divided into 17 responders and 17 non-responders based on echocardiographic response criteria: either an increase in ejection fraction (EF) ≥10% or a reduction in left ventricular (LV) end-systolic volume ≥10%. Baseline characteristics including peak oxygen uptake (V̇O₂) and isometric knee extensor muscle strength (IKEMS) were similar in both groups, but non-responders had lower EF and larger LV. During the ET program, neither group had exercise-related adverse event including life-threatening ventricular arrhythmia. Peak V̇O₂ and IKEMS were significantly improved in both groups and there was no significant difference in change in peak V̇O₂ or IKEMS between responders and non-responders. On multiple regression analysis, change in IKEMS was an independent predictor of change in peak V̇O₂, whereas the response to CRT was not.

Conclusions: In HF patients undergoing CRT implantation, ET safely improved exercise capacity regardless of response to CRT, suggesting that even advanced HF patients without response to CRT can possibly benefit from ET.

B-type natriuretic peptide is associated with remodeling and exercise capacity after transcatheter aortic valve replacement for aortic stenosis

Background

We aimed to assess longitudinal changes of B‐type natriuretic peptide (BNP) in aortic stenosis (AS) patients treated by transcatheter aortic valve replacement (TAVR).

Methods

From our TAVR database, we identified 193 consecutive patients with severe symptomatic AS who underwent TAVR and were prospectively followed using serial BNP levels and echocardiography. Patients were divided into subgroups according to type of left ventricular (LV) remodeling as having normal LV mass and relative wall thickness, or showing concentric remodeling (CR), concentric hypertrophy (CH), and eccentric hypertrophy (EH).

Results

At baseline, 30 patients (16%) had EH, 115 (60%) had CH, 37 (19%) had CR, and 11 (6%) had normal LV geometry. After TAVR, BNP decreased in the first 30 days, with further improvement during follow‐up. Patients with EH had higher BNP at baseline (P < 0.01) and a greater subsequent decrease (P < 0.001). During the median follow‐up of 1331 days (interquartile range: 632‐1678), 119 (62%) patients died. BNP showed a time‐dependent association with all‐cause mortality both in a univariable (hazards ratio [HR] 1.24, 95% confidence interval [CI]: 1.04‐1.47, P = 0.017), and in a multivariable model with Society of Thoracic Surgeons score and baseline BNP forced into the analysis (HR 1.32, 95% CI: 1.001‐1.73, P = 0.049). Elevated BNP was associated with a larger LV end‐diastolic volume index (P < 0.001) and shorter 6‐minute walk test distance (P = 0.013) throughout follow‐up.

Conclusion

In patients with AS, BNP was associated with LV remodeling phenotypes and functional status before and after TAVR. Elevated BNP levels were associated with poor prognosis.

Current role of echocardiography in cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) is an established treatment for patients with heart failure and left ventricular systolic dysfunction. Patients are usually assessed by echocardiography, which provides a number of anatomical and functional information used for cardiac dyssynchrony assessment, prognostic stratification, identification of the optimal site of pacing in the left ventricle, optimization of the CRT device, and patient follow-up. Compared to other cardiac imaging techniques, echocardiography has the advantage to be non-invasive, repeatable, and safe, without exposure to ionizing radiation or nefrotoxic contrast. In this article, we review current evidence about the role of echocardiography before, during, and after the implantation of a CRT device.

Association of cardiac resynchronization therapy with the incidence of appropriate implantable cardiac defibrillator therapies in ischaemic and non-ischaemic cardiomyopathy

Aims

Cardiac resynchronization therapy (CRT) reduces the incidence of sudden cardiac death and the use of appropriate implantable cardioverter-defibrillator (ICD) therapies (AICDTs); however, this antiarrhythmic effect is only observed in certain groups of patients. To gain insight into the effects of CRT on ventricular arrhythmia (VA) burden, we compared the incidence of AICDT use in four groups of patients: patients with ischaemic cardiomyopathy vs. non-ischaemic dilated cardiomyopathy (NIDC) and patients implanted with an ICD vs. CRT-ICD.

Methods and results

We analysed 689 consecutive patients (mean follow-up 37 ± 16 months) included in the Umbrella registry, a multicentre prospective registry including patients implanted with ICD or CRT-ICD devices with remote monitoring capabilities in 48 Spanish Hospitals. The primary outcome was the time to first AICDT. Despite a worse clinical risk profile, NIDC patients receiving a CRT-ICD had a lower cumulative probability of first AICDT use at 2 years compared with patients implanted with an ICD [24.7 vs. 41.6%, hazard ratio (HR): 0.49, P = 0.003]; on the other hand, there were no significant differences in the incidence of first AICDT use at 2 years in ischaemic patients (22.6 vs. 21.9%, P = NS). Multivariate analysis confirmed the association of CRT with lower AICDT rates amongst NIDC patients (Adjusted HR: 0.55, CI 95% 0.35-0.87).

Conclusions

These data suggest that CRT is associated with significantly lower rates of first AICDT use in NIDC patients, but not in ischaemic patients. This study suggests that ICD patients with NIDC and left bundle branch block experiencing VAs may benefit from an upgrade to CRT-ICD despite being in a good functional class.

Reverse remodeling in Dilated Cardiomyopathy: Insights and future perspectives

Dilated Cardiomyopathy (DCM) has been classically considered a progressive disease of the heart muscle that inexorably progresses towards refractory heart failure, ventricular arrhythmias and heart transplant. However, the prognosis of DCM has significantly improved in the past few years, mostly as the result of successful therapy-induced reverse remodeling. Reverse remodeling is a complex process that involves not only the left ventricle, but also many other cardiac structures and it is now recognized both as a measure of therapeutic effectiveness and as an important prognostic tool. Nevertheless, several aspects of reverse remodeling remain unclear, including the best timing for its quantification, its predictors and its interaction with individual genetic backgrounds. In this review, we summarize our current understanding of reverse remodeling in patients with DCM and provide practical recommendations for the clinical management of this challenging patient population.

The incidence and outcomes of delayed response to cardiac resynchronization therapy

BACKGROUND

The incidence and clinical outcomes of delayed response to cardiac resynchronization therapy (CRT) have not been well clarified. We aimed to observe the incidence and prognosis of delayed response and to identify its possible mechanisms.

METHODS

A total of 115 CRT patients were retrospectively analyzed in our study. Patients who met the enrollment criteria were divided into two groups: group A, conventional responders who showed response at 1-year follow-up, and group B, delayed responders who showed response after 1-year follow-up. CRT response was defined as an absolute increase of ≥10% in left ventricular ejection fraction.

RESULTS

Fifty-two patients (61 ± 12 years, 37 male) experienced conventional response to CRT and 17 patients (63 ± 11 years, 10 male) experienced delayed response. The mean follow-up time was 5.2 ± 2.4 years. The incidence of delayed response was 14.8% (17/115). All-cause mortality and hospitalization rates for heart failure were similar for delayed and conventional responders. Multivariate logistic regression analysis revealed that scar burden > 35% was an independent predictor of CRT delayed response (odds ratio 8.794, P  =  0.038).

CONCLUSIONS

A significant proportion of patients demonstrated delayed response to CRT. The delayed responders had a good prognosis that was similar to that of conventional responders. More scar burden might be related to the incidence of delayed response.

Reversibility of Cardiac Function Predicts Outcome After Transcatheter Aortic Valve Replacement in Patients With Severe Aortic Stenosis

Background

Reversibility of left ventricular (LV) dysfunction in high‐risk aortic stenosis patient and its impact on survival after transcatheter aortic valve replacement (TAVR) are unclear. We aimed to evaluate longitudinal changes of LV structure and function after TAVR and their impact on survival.

Methods and Results

We studied 209 patients with aortic stenosis who underwent TAVR from May 2006 to December 2012. Echocardiograms were used to calculate LV end‐diastolic volume index (LVEDVi), LV ejection fraction, LV mass index (LVMi), and global longitudinal strain before, immediately (<10 days), late (1–3 months), and yearly after TAVR. During a median follow‐up of 1345 days, 118 patients died, with 26 dying within 1 year. Global longitudinal strain, LVEDVi, LV ejection fraction, and LVMi improved during follow‐up. In patients who died during the first year, death was preceded by LVEDVi and LVMi increase. Multivariable longitudinal data analysis showed that aortic regurgitation at baseline, aortic regurgitation at 30 days, and initial LVEDVi were independent predictors of subsequent LVEDVi. In a joint analysis of longitudinal and survival data, baseline Society of Thoracic Surgeons score was predictive of survival, with no additive effect of longitudinal changes in LVEDVi, LVMi, global longitudinal strain, or LV ejection fraction. Presence of aortic regurgitation at 1 month after TAVR was the only predictor of 1‐year survival.

Conclusions

LV reverse remodeling was observed after TAVR, whereas lack of LVEDVi and LVMi improvement was observed in patients who died during the first year after TAVR. Post‐TAVR, aortic regurgitation blocks reverse remodeling and is associated with poor 1‐year survival after TAVR.

Comparison of De Novo versus Upgrade Cardiac Resynchronization Therapy; Focused on the Upgrade for Pacing-Induced Cardiomyopathy

PURPOSE

This study aimed to determine whether upgrade cardiac resynchronization therapy (CRT) shows better outcomes than de novo CRT. To do so, we compared the efficacy of CRT between de novo and upgrade groups, focusing particularly on the effect of upgrade CRT on patients with pacing-induced cardiomyopathy (PiCM).

MATERIALS AND METHODS

PiCM was defined as new-onset dilated cardiomyopathy following pacemaker implantation in patients with baseline normal ejection fraction ≥50%. Electro-mechanical reverse remodeling and clinical outcomes were compared among the de novo (n=62), PiCM upgrade (n=7), and non-PiCM upgrade (n=8) CRT groups.

RESULTS

The PiCM upgrade group showed significantly greater electro-mechanical reverse remodeling than the de novo CRT or non-PiCM upgrade groups at 6-month follow-up. The rate of super-responders was significantly higher in the PiCM upgrade group than the other CRT groups. The group factor of the PiCM upgrade was identified as an independent predictor of super-responder in multivariate analysis (odds ratio 10.4, 95% confidential interval 1.08-99.4, p=0.043). During the median follow-up of 15.8 months, the PiCM upgrade group showed the lowest rate of composite clinical outcomes, including cardiac death, heart transplantation, and heart failure-related rehospitalization (p=0.059).

CONCLUSION

The upgrade CRT for PiCM patients showed better performance in terms of electro-mechanical reverse remodeling than de novo implantation or upgrade CRT in non-PiCM patients.

Long-Term Echocardiographic Outcome in Super-Responders to Cardiac Resynchronization Therapy and the Association With Mortality and Defibrillator Therapy

Super-response to cardiac resynchronization therapy (CRT) is associated with significant left ventricular (LV) reverse remodeling and improved clinical outcome. The study aimed to: (1) evaluate whether LV reverse remodeling remains sustained during long-term follow-up in super-responders and (2) analyze the association between the course of LV reverse remodeling and ventricular arrhythmias. Of all, primary prevention super-responders to CRT were selected. Super-response was defined as LV end-systolic volume reduction of ≥30% 6 months after device implantation. Cox regression analysis was performed to investigate the association of LV ejection fraction (LVEF) as time-dependent variable with implantable-cardioverter defibrillator (ICD) therapy and mortality. A total of 171 super-responders to CRT-defibrillator were included (mean age 67 ± 9 years; 66% men; 37% ischemic heart disease). Here of 129 patients received at least 1 echocardiographic evaluation after a median follow-up of 62 months (25th to 75th percentile, 38 to 87). LV end-diastolic volume, LV end-systolic volume, and LVEF after 6-month follow-up were comparable with those after 62-month follow-up (p = 0.90, p = 0.37, and p = 0.55, respectively). Changes in LVEF during follow-up in super-responders were independently associated with appropriate ICD therapy (hazard ratio 0.94, 95% CI 0.90 to 0.98; p = 0.005) and all-cause mortality (hazard ratio 0.95, 95% CI 0.91 to 1.00; p = 0.04). A 5% increase in LVEF was associated with a 1.37 times lower risk of appropriate ICD therapy and a 1.30 times lower risk of mortality. In conclusion, LV reverse remodeling in super-responders to CRT remains sustained during long-term follow-up. Changes in LVEF during follow-up were associated with mortality and ICD therapy.

Strain-time curve analysis by speckle tracking echocardiography in cardiac resynchronization therapy: Insight into the pathophysiology of responders vs. non-responders

Background

Patients with non-ischemic heart failure etiology and left bundle branch block (LBBB) show better response to cardiac resynchronization therapy (CRT). While these patients have the most pronounced left ventricular (LV) dyssynchrony, LV dyssynchrony assessment often fails to predict outcome. We hypothesized that patients with favorable outcome from CRT can be identified by a characteristic strain distribution pattern.

Methods

From 313 patients who underwent CRT between 2003 and 2006, we identified 10 patients who were CRT non-responders (no LV end-systolic volume [LVESV] reduction) with non-ischemic cardiomyopathy and LBBB and compared with randomly selected CRT responders (n = 10; LVESV reduction ≥15 %). Longitudinal strain (ε_long) data were obtained by speckle tracking echocardiography before and after (9 ± 5 months) CRT implantation and standardized segmental ε_long-time curves were obtained by averaging individual patients.

Results

In responders, ejection fraction (EF) increased from 25 ± 9 to 40 ± 11 % (p = 0.002), while in non-responders, EF was unchanged (20 ± 8 to 21 ± 5 %, p = 0.57). Global ε_long was significantly lower in non-responders at pre CRT (p = 0.02) and only improved in responders (p = 0.04) after CRT. Pre CRT septal ε_long -time curves in both groups showed early septal contraction with mid-systolic decrease, while lateral ε_long showed early stretch followed by vigorous mid to late contraction. Restoration of contraction synchrony was observed in both groups, though non-responder remained low amplitude of ε_long.

Conclusions

CRT non-responders with LBBB and non-ischemic etiology showed a similar improvement of ε_long pattern with responders after CRT implantation, while amplitude of ε_long remained unchanged. Lower ε_long in the non-responders may account for their poor response to CRT.

Optimal cut-off value of reverse remodeling to predict long-term outcome after cardiac resynchronization therapy in patients with ischemic cardiomyopathy

BACKGROUND

Whether the optimal cut-off value of left ventricular (LV) reverse remodeling is different in patients with ischemic cardiomyopathy (ICM) vs. non-ischemic cardiomyopathy (NICM) is unclear. This study aimed to clarify this value in patients with ICM and NICM.

METHODS AND RESULTS

LV reverse remodeling was defined as a reduction in LV end-systolic volume (LVESV) at 6 months after cardiac resynchronization therapy (CRT). The clinical endpoint was the combination of cardiac death and first hospitalization for worsening heart failure. Ninety-one of 372 patients had ICM. Event-free survival rates did not differ between ICM and NICM groups (66.8% vs. 78.9%; p=0.12). Receiver operating characteristics analysis revealed a 9% reduction in ESV as the optimal cut-off value to predict the composite endpoint in patients with ICM and a 15% reduction in patients with NICM. Multivariate analysis revealed that reductions in ESV of ≥15% and ≥9% were independent predictors of the composite endpoint, as were left bundle branch block (LBBB) and B-type natriuretic peptide (BNP) at 6 months after CRT. In combination with LBBB and BNP, reduction in ESV ≥9% had a higher, but not significant, C-statistics value than ESV ≥15% (0.854, 95% CI 0.729-0.940 vs. 0.801, 95% CI 0.702-0.908, p=0.07).

CONCLUSION

The optimal cut-off value of a reduction in LVESV was lower in patients with ICM than in patients with NICM.

Nuclear Image-Guided Approaches for Cardiac Resynchronization Therapy (CRT)

Cardiac resynchronization therapy (CRT) is a standard treatment for patients with heart failure. However, 30-40 % of the patients having CRT do not respond to CRT with improved clinical symptom and cardiac functions. It is important for CRT response that left ventricular (LV) lead is placed away from scar and at or near the site of the latest mechanical activation. Nuclear image-guided approaches for CRT have shown significant clinical value to assess LV myocardial viability and mechanical dyssynchrony, recommend the optimal LV lead position, and navigate the LV lead to the target coronary venous site. All these techniques, once validated and implemented, should impact the current clinical practice.

Long-Term Echocardiographic Response to Cardiac Resynchronization Therapy in Initial Nonresponders

OBJECTIVES

The aim of this study was to investigate the frequency and clinical implications of a delayed echocardiographic response to cardiac resynchronization therapy (CRT).

BACKGROUND

Long-term prognosis for CRT patients is routinely based on the assessment of echocardiograms after 6 to 12 months of therapy. Some patients, however, may require a longer period of therapy before echocardiographic improvements are detectable.

METHODS

This observational study included all patients with heart failure (HF) receiving a CRT device at a single center from 2003 to 2011. Eligible patients met current indications and had technically adequate echocardiograms from before implantation, approximately 1 year after implantation (mid-term), and ≥3 years after implantation (long-term). A positive echocardiographic response to CRT was defined as a reduction in left ventricular end-systolic volume ≥15%. All-cause mortality was compared for patients in 3 response groups: mid-term responders, long-term responders, and nonresponders.

RESULTS

During this study, 294 patients met the study criteria. Of the 120 patients who were nonresponders after 1 year, 52 (43%) experienced a delayed positive response. Delayed, long-term responders had mortality and hospitalization rates similar to mid-term responders and significantly lower than nonresponders.

CONCLUSIONS

Among patients surviving at least 3 years after implantation of a CRT device and with echocardiographic follow-up, a significant portion of nonresponders after 1 year of CRT experience a delayed echocardiographic response after a longer period of time. Survival and hospitalization rates were similar for all echocardiographic responders, regardless of the time at which the response occurred.

Development and Validation of Predictive Models of Cardiac Mortality and Transplantation in Resynchronization Therapy

Background

30-40% of cardiac resynchronization therapy cases do not achieve favorable outcomes.

Objective

This study aimed to develop predictive models for the combined endpoint of cardiac death and transplantation (Tx) at different stages of cardiac resynchronization therapy (CRT).

Methods

Prospective observational study of 116 patients aged 64.8 ± 11.1 years, 68.1% of whom had functional class (FC) III and 31.9% had ambulatory class IV. Clinical, electrocardiographic and echocardiographic variables were assessed by using Cox regression and Kaplan-Meier curves.

Results

The cardiac mortality/Tx rate was 16.3% during the follow-up period of 34.0 ± 17.9 months. Prior to implantation, right ventricular dysfunction (RVD), ejection fraction < 25% and use of high doses of diuretics (HDD) increased the risk of cardiac death and Tx by 3.9-, 4.8-, and 5.9-fold, respectively. In the first year after CRT, RVD, HDD and hospitalization due to congestive heart failure increased the risk of death at hazard ratios of 3.5, 5.3, and 12.5, respectively. In the second year after CRT, RVD and FC III/IV were significant risk factors of mortality in the multivariate Cox model. The accuracy rates of the models were 84.6% at preimplantation, 93% in the first year after CRT, and 90.5% in the second year after CRT. The models were validated by bootstrapping.

Conclusion

We developed predictive models of cardiac death and Tx at different stages of CRT based on the analysis of simple and easily obtainable clinical and echocardiographic variables. The models showed good accuracy and adjustment, were validated internally, and are useful in the selection, monitoring and counseling of patients indicated for CRT.

Sex differences in device therapy for heart failure: utilization, outcomes, and adverse events

BACKGROUND

Multiple studies of heart failure patients demonstrated significant improvement in exercise capacity, quality of life, cardiac left ventricular function, and survival from cardiac resynchronization therapy (CRT), but the underenrollment of women in these studies is notable. Etiological and pathophysiological differences may result in different outcomes in response to this treatment by sex. The observed disproportionate representation of women suggests that many women with heart failure either do not meet current clinical criteria to receive CRT in trials or are not properly recruited and maintained in these studies.

METHODS

We performed a systematic literature review through May 2014 of clinical trials and registries of CRT use that stratified outcomes by sex or reported percent women included. One-hundred eighty-three studies contained sex-specific information.

RESULTS

Ninety percent of the studies evaluated included ≤ 35% women. Fifty-six articles included effectiveness data that reported response with regard to specific outcome parameters. When compared with men, women exhibited more dramatic improvement in specific parameters. In the studies reporting hazard ratios for hospitalization or death, women generally had greater benefit from CRT.

CONCLUSIONS

Our review confirms women are markedly underrepresented in CRT trials, and when a CRT device is implanted, women have a therapeutic response that is equivalent to or better than in men, while there is no difference in adverse events reported by sex.

Cardiac Resynchronisation Therapy or MitraClip® Implantation for Patients with Severe Mitral Regurgitation and Left Bundle Branch Block?

Secondary or functional mitral regurgitation (FMR) is a common problem in patients with chronic heart failure (HF). About one-third of patients with chronic HF also have left bundle branch block (LBBB). Approximately one-third of patients with an indication for cardiac resynchronisation therapy (CRT) have moderate-to-severe FMR. This FMR may either be a consequence of systolic dysfunction or it may occur due to dyssynchrony. Both directly reducing FMR and correcting cardiac dyssynchrony are viable therapeutic approaches in selected patients, according to the 2012 European Society of Cardiology (ESC) Guidelines for valvular heart disease. Initial presence of FMR is an independent predictor of lack of clinical response to CRT. Patients undergoing CRT without signs of significant clinical improvement may be considered candidates for the percutaneous MitraClip® procedure. As yet, there are not enough data to select patients that would benefit from being treated primarily with MitraClip. A clinical trial in HF patients to be randomised to either MitraClip procedure or CRT is needed to confirm actual ESC Guideline therapy.

Chronic vagal stimulation for the treatment of low ejection fraction heart failure: results of the NEural Cardiac TherApy foR Heart Failure (NECTAR-HF) randomized controlled trial

Aim

The neural cardiac therapy for heart failure (NECTAR-HF) was a randomized sham-controlled trial designed to evaluate whether a single dose of vagal nerve stimulation (VNS) would attenuate cardiac remodelling, improve cardiac function and increase exercise capacity in symptomatic heart failure patients with severe left ventricular (LV) systolic dysfunction despite guideline recommended medical therapy.

Methods

Patients were randomized in a 2 : 1 ratio to receive therapy (VNS ON) or control (VNS OFF) for a 6-month period. The primary endpoint was the change in LV end systolic diameter (LVESD) at 6 months for control vs. therapy, with secondary endpoints of other echocardiography measurements, exercise capacity, quality-of-life assessments, 24-h Holter, and circulating biomarkers.

Results

Of the 96 implanted patients, 87 had paired datasets for the primary endpoint. Change in LVESD from baseline to 6 months was −0.04 ± 0.25 cm in the therapy group compared with −0.08 ± 0.32 cm in the control group (P = 0.60). Additional echocardiographic parameters of LV end diastolic dimension, LV end systolic volume, left ventricular end diastolic volume, LV ejection fraction, peak V0₂, and N-terminal pro-hormone brain natriuretic peptide failed to show superiority compared to the control group. However, there were statistically significant improvements in quality of life for the Minnesota Living with Heart Failure Questionnaire (P = 0.049), New York Heart Association class (P = 0.032), and the SF-36 Physical Component (P = 0.016) in the therapy group.

Conclusion

Vagal nerve stimulation as delivered in the NECTAR-HF trial failed to demonstrate a significant effect on primary and secondary endpoint measures of cardiac remodelling and functional capacity in symptomatic heart failure patients, but quality-of-life measures showed significant improvement.

Implications of left bundle branch block in patient treatment

Left bundle branch block (LBBB) causes an abnormal pattern of cardiac activation and affects regional myocardial function. Although recognition of LBBB on the surface electrocardiogram is straightforward, dissecting its effect on patient treatment and outcome can be more challenging. The altered pattern of cardiac activation in LBBB causes electrical and mechanical ventricular dyssynchrony, influences ischemia detection on the surface electrocardiogram, and affects stress testing and imaging modalities dependent on wall motion and thickening. Restoration of synchrony by biventricular pacing can improve symptoms and longevity in carefully selected patients. The diagnostic, prognostic, and therapeutic implications of LBBB across this spectrum are discussed in this review.