Efficacy of optimal medical therapy and cardiac resynchronization therapy upgrade in patients with pacemaker-induced cardiomyopathy

Mid-term outcomes of delivery catheter-based and stylet-based right ventricular septal pacing: Follow-up results from a multicenter, prospective, randomized study

Background

The Mt FUJI study was a multicenter, prospective, randomized, single-blind, controlled trial comparing delivery catheter-based and stylet-based right ventricular (RV) lead placement at the RV septum. This study extended the follow-up duration to 1 year after implantation.

Methods

Seventy patients with pacemaker indications for atrioventricular block were randomly assigned to the delivery catheter and stylet groups. We compared the mid-term efficacy and safety between the two groups at 1 year after implantation. The primary outcome was the change in the left ventricular ejection fraction (LVEF), and the secondary outcomes were changes in brain natriuretic peptide (BNP) levels, lead parameters, paced QRS duration, and the incidence of adverse events.

Results

At the 1-year follow-up, no significant differences were observed in the changes in the LVEF (+1.0% ± 8.6% vs. +3.1% ± 8.1%, p = .332), BNP levels (+8.0 [-11.1, 26.5] pg/mL vs. -8.7 [-15.3, 13.2] pg/mL, p = .193), or lead performance between the delivery catheter and stylet groups. The QRS duration was significantly shorter in the delivery catheter group than in the stylet group (128 ± 23 ms vs. 146 ± 17 ms, p < .001). All-cause death, hospitalization for heart failure, new development of atrial fibrillation, and pacing-induced cardiomyopathy occurred in seven patients in the delivery catheter group and five in the stylet group.

Conclusion

The delivery catheter system was similarly useful and safe compared to the stylet system in the mid-term follow-up from the Mt FUJI trial. Further long-term evaluations are warranted.

Pacemaker-induced Cardiomyopathy in Patients with Coronary Artery Disease: A Report of Three Cases

Pacing-induced cardiomyopathy (PICM) is defined as a drop in left ventricular ejection fraction (LVEF) in the setting of chronic, high-burden right ventricular pacing. Cardiac resynchronization therapy (CRT) and conduction system pacing (CSP) have been proposed to manage PICM. Although acute myocardial infarction has been described as a predictor of PICM, there are no guideline recommendations for CRT or CSP in patients with coronary artery disease (CAD) and preserved LVEF. In this report, we present and discuss three cases of PICM in patients with CAD and preserved LVEF.

Sex-based differences in cardiac resynchronization therapy upgrade and outcome for patients with pacemaker and new-onset heart failure

BACKGROUND

Patients with chronic right ventricular (RV) pacing are at an increased risk of heart failure. Previous studies have indicated that cardiac resynchronization therapy (CRT) is underused in this setting, and that there may be sex-based differences in both CRT use and clinical outcome.

OBJECTIVE

To evaluate sex-based differences in CRT use and clinical outcome for patients with new-onset heart failure post RV pacing.

METHODS

Data from the Swedish pacemaker registry was matched with data from the national death and disease registries. Patients with de novo pacemaker implant due to AV block during the period 2005-2020 were included. New-onset heart-failure within two years post-implant was evaluated, primary outcome was all-cause mortality.

RESULTS

In all, 30183 patients (37% female) were included. Women were on average 3 years older, but had less comorbidities than men. Median follow-up time was 4.5 [2.0-8.0] years. Women had better age- and comorbidity-adjusted survival (HR 0.78 [0.73-0.84], p < .001). For the 3560 patients (12.4% men and 10.7% women, p < .001) who were diagnosed with new-onset heart failure, 5-year mortality was similar for men and women (50% vs. 48%, p = .29). However, women were less likely to receive CRT-upgrade (3.8% vs. 9.1%, p < .001), and those who did were almost ten years younger than the men.

CONCLUSION

Women with pacemaker due to AV block are older but have less comorbidities than men. They are less likely to develop new-onset heart failure, but also less likely to receive a CRT upgrade if they do develop heart failure. Increased awareness of the positive effects of CRT upgrade and potential sex- and age-based discrimination is warranted.

Efficacy of CRT upgrade in pacemaker-induced cardiomyopathy in an outpatient clinic - Results of a prospective registry

PURPOSE

The aim of this prospective, monocentric registry study was to investigate whether upgrading to cardiac resynchronization therapy (CRT) in pacemaker-induced cardiomyopathy (PICM) can improve left ventricular function in typical outpatient clinical patients.

METHODS

We screened for PICM in a pacemaker outpatient clinic between 2017 and 2021. The follow-up period was 6 months. The primary endpoint was decreased left ventricular end systolic volume (LVESV), and the responder criterion was decreased LVESV >15%. Secondary endpoints were LVEF, NYHA class, device-associated complications and death.

RESULTS

66 patients were newly diagnosed with PICM. 55 of them received a CRT upgrade. For the primary endpoint, LVESV decreased from 101.6 ± 48.2 ml to 75.9 ± 35.8 ml (p < 0.001). Secondary endpoints were: a) LVEF increased from 31.5 ± 5.4% to 46.1 ± 7.6% (p < 0.001) and b) NYHA class improved by an average of one class in both groups (p < 0.001). The overall complication rate was 1.8%.

CONCLUSIONS

CRT upgrade in outpatient clinic patients with PICM improves left ventricular function and functional capacity and is associated with an acceptable complication rate.

Upgrading right ventricular pacemakers to biventricular pacing or conduction system pacing: a systematic review and meta-analysis

Guidelines recommend patients undergoing a first pacemaker implant who have even mild left ventricular (LV) impairment should receive biventricular or conduction system pacing (CSP). There is no corresponding recommendation for patients who already have a pacemaker. We conducted a meta-analysis of randomized controlled trials (RCTs) and observational studies assessing device upgrades. The primary outcome was the echocardiographic change in LV ejection fraction (LVEF). Six RCTs (randomizing 161 patients) and 47 observational studies (2644 patients) assessing the efficacy of upgrade to biventricular pacing were eligible for analysis. Eight observational studies recruiting 217 patients of CSP upgrade were also eligible. Fourteen additional studies contributed data on complications (25 412 patients). Randomized controlled trials of biventricular pacing upgrade showed LVEF improvement of +8.4% from 35.5% and observational studies: +8.4% from 25.7%. Observational studies of left bundle branch area pacing upgrade showed +11.1% improvement from 39.0% and observational studies of His bundle pacing upgrade showed +12.7% improvement from 36.0%. New York Heart Association class decreased by -0.4, -0.8, -1.0, and -1.2, respectively. Randomized controlled trials of biventricular upgrade found improvement in Minnesota Heart Failure Score (-6.9 points) and peak oxygen uptake (+1.1 mL/kg/min). This was also seen in observational studies of biventricular upgrades (-19.67 points and +2.63 mL/kg/min, respectively). In studies of the biventricular upgrade, complication rates averaged 2% for pneumothorax, 1.4% for tamponade, and 3.7% for infection over 24 months of mean follow-up. Lead-related complications occurred in 3.3% of biventricular upgrades and 1.8% of CSP upgrades. Randomized controlled trials show significant physiological and symptomatic benefits of upgrading pacemakers to biventricular pacing. Observational studies show similar effects between biventricular pacing upgrade and CSP upgrade.

Adverse effects of right ventricular pacing on cardiac function: prevalence, prevention and treatment with physiologic pacing

Right ventricular (RV) pacing is the main treatment modality for patients with advanced atrioventricular (AV) block. Chronic RV pacing can cause cardiac systolic dysfunction and heart failure (HF). In this review, we discuss studies that have shown deleterious effects of chronic RV pacing on systolic cardiac function causing pacing-induced cardiomyopathy (PiCM), heart failure (HF), HF hospitalization, atrial fibrillation (AF) and cardiac mortality. RV apical pacing is the most widely used and studied. Adverse effects of RV pacing appear to be directly related to pacing burden and are worse in patients with pre-existing left ventricular (LV) dysfunction. Chronic RV pacing is also associated with heart failure with preserved ejection fraction (HFpEF). Mechanisms, risk factors, clinical and echocardiographic features, and strategies to minimize RV pacing-induced cardiac dysfunction are discussed in light of the latest data. Studies on biventricular (Bi-V) pacing upgrade in patients who develop RV PiCM, use of alternate RV pacing sites, de novo Bi-V pacing, and physiologic pacing using HIS bundle pacing (HBP) and left bundle area (LBBA) pacing in patients with an anticipated high RV pacing burden are discussed.

Pacing-induced cardiomyopathy: A systematic review and meta-analysis of definition, prevalence, risk factors, and management

Pacing-induced cardiomyopathy is a potential complication of right ventricular pacing. Definition varies between studies and the optimal management approach is uncertain. We aimed to characterize definition, prevalence, risk factors, and treatment strategies of pacing-induced cardiomyopathy (PiCM). We performed a systematic review and meta-analysis of studies that evaluated PiCM after pacemaker implantation identified through a literature search of PubMed and EMBASE up to March 2022. We collected data on the study definition of PiCM and calculated pooled prevalence across studies. Meta-analysis with random effects modeling was used to assess the association between potential risk factors and PiCM, reported as odds ratio with 95% confidence interval. Twenty-six studies (6 prospective studies) with a total of 57,993 patients (mean/median age range was 51-78 years; female 45%) were included in the final analysis. Fifteen unique definitions of PiCM were reported. The pooled prevalence of PiCM was 12% (95% confidence interval 11%-14%). In meta-analysis, risk factors included male sex, history of myocardial infarction, chronic kidney disease, atrial fibrillation, baseline left ventricular ejection fraction, native QRS duration, right ventricular pacing percentage, and paced QRS duration. Treatment strategies identified included biventricular cardiac resynchronization therapy (6 studies) and His-bundle pacing (3 studies). Definition of PiCM varied significantly between studies. More than 1 in 10 patients with chronic right ventricular pacing developed PiCM. Key risk factors included baseline left ventricular ejection fraction, native QRS duration, RV pacing percentage, and paced QRS duration. The optimal management strategy has yet to be defined. Further research is needed to define and treat this understated complication.

The Therapeutic Benefit of Upgrade to Cardiac Resynchronization Therapy in Patients with Pacing Induced Cardiomyopathy

Background

Pacing-induced cardiomyopathy (PICM) is an important cause of heart failure in patients with a right ventricular pacing burden. Recent evidence suggests that an upgrade to cardiac resynchronization therapy (CRT) may confer benefit in PICM.

Objective

To assess the extent and identify predictors of improvement following upgrade to CRT in patients with PICM.

Methods

We retrospectively analyzed 43 patients undergoing CRT upgrade for PICM over the 10-year period of 2011 to 2021 at our center. All patients with PICM who underwent device upgrade from a dual- or single-chamber ventricular pacemaker to CRT were included. PICM was defined as a decrease of ≥10% in left ventricular ejection fraction (LVEF), resulting in an LVEF <50% among patients with ≥20% Right ventricular pacing burden without an alternative cause for cardiomyopathy.

Results

LVEF significantly improved from 28.7% preupgrade to 44.3% post-CRT upgrade (P < .01). Of 37 patients with severe LV dysfunction, 34 (91.9%) improved to an LVEF >35% and 13 (35.1%) improved to an LVEF >50%. The LV end-diastolic diameter decreased from 5.9 cm preupgrade to 5.4 cm postupgrade (P < .01). Using linear regression, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use was associated with significant LVEF improvement (+7.21%, P = .05). We observed a low rate of complications, and 1 in 4 CRT upgrades required venoplasty (n = 10 of 43, 23.3%).

Conclusion

We provide further evidence for the benefit of CRT upgrade in the management of patients with PICM.

Dyssynchronous Heart Failure: A Clinical Review

PURPOSE OF THE REVIEW

Dyssynchrony occurs when portions of the cardiac chambers contract in an uncoordinated fashion. Ventricular dyssynchrony primarily impacts the left ventricle and may result in heart failure. This entity is recognized as a major contributor to the development and progression of heart failure. A hallmark of dyssynchronous heart failure (HF_d) is left ventricular recovery after dyssynchrony is corrected. This review discusses the current understanding of pathophysiology of HF_d and provides clinical examples and current techniques for treatment.

RECENT FINDINGS

Data show that HF_d responds poorly to medical therapy. Cardiac resynchronization therapy (CRT) in the form of conventional biventricular pacing (BVP) is of proven benefit in HF_d, but is limited by a significant non-responder rate. Recently, conduction system pacing (His bundle or left bundle branch area pacing) has also shown promise in correcting HF_d. HF_d should be recognized as a distinct etiology of heart failure; HF_d responds best to CRT.

Incidence and predictors of pacemaker-induced cardiomyopathy with right ventricular pacing: a systematic review

INTRODUCTION

This systematic review aims to evaluate the incidence and predictors of PICM in patients undergoing right ventricular pacing.

AREAS COVERED

A literature review was conducted using Mesh terms (Right ventricular pacing, Pacemaker-related cardiomyopathy, Pacemaker-induced cardiomyopathy) in PubMed, EMBASE, Web of science CINAHL, and the Cochrane Library until October 2021. All data reporting the incidence of PICM after implantation of right-sided pacemakers or implantable cardioverter-defibrillator (ICD) were retrieved from the eligible studies.

EXPERT OPINION

Out of 3,625 articles, 20 studies met the inclusion criteria that included 5,381 patients with PICM. The mean age of the patients ranged between 55.8 ± 13.5 and 77.4 ± 10.8 years. The mean incidence of PICM was 25.7%. Mean EF at baseline ranged from 48 ± 1% and 62.1 ± 11.2%, while mean EF at follow up ranged between 33.7± 7.4% and 53.2 ± 8.2%. Three studies reported a decline of >20% EF at follow-up. RV pacing was associated with a considerable risk of PICM, with biological factors such as male gender, old age, increased QRS duration, and chronic RV pacing burden playing an important role in the development of disease.

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.

Incidence and Clinical Outcomes of Pacing Induced Cardiomyopathy in Patients With Normal Left Ventricular Systolic Function and Atrioventricular Block

Patients with preserved left ventricular (LV) ejection function (EF) and atrioventricular block (AVB) who are anticipated for high-burden of right ventricular (RV) pacing possess a risk to develop pacing-induced cardiomyopathy (PIC) and adverse clinical outcomes. Hence, the aim of the study is to evaluate the incidence, predictors, and clinical outcomes of RV PIC in patients with preserved LVEF, AVB, and high-burden of RV pacing. One thousand and thirteen patients with second or third-degree AVB underwent first time pacemaker implantation between January 2002 and August 2016. A total of 203 patients with a newly implanted pacemaker, normal baseline LVEF, and high burden of RV pacing were included in the present study. Follow-up echocardiography was examined for a new decrease in LVEF of 10% or higher. Alternative causes for cardiomyopathy were ruled out. Patient characteristics, echocardiographic measurements, device clinic data, mortality, and hospitalizations for heart failure were collected and compared between the PIC and the non-PIC groups. Fifty-one patients (25%) developed LV dysfunction with 22 patients (11%), showing LVEF < 40%. During a mean follow-up of 49.2 months, the risk of heart failure hospitalization or all-cause mortality was significantly higher in the PIC group versus non-PIC group (35.3% vs 19.1%, p = 0.009). In conclusion the incidence of PIC in patients with normal LVEF and AVB, who are anticipated for high-burden of RV pacing is high. PIC in patients with a previously normal LV function is associated with unfavorable long-term clinical outcomes, including higher rates of heart failure hospitalizations and all-cause mortality.

Prevalence of left ventricular systolic dysfunction in a typical outpatient pacemaker cohort

Background

Right ventricular (RV) pacing is the standard treatment for symptomatic bradycardia. RV pacing is known to cause dyssyncrony. New treatment options like His bundle pacing enhance the focus on left ventricular dysfunction in patients with pacemakers.

Objectives

The aim of this cross-sectional study was to obtain a real-life picture of the patients in a representative cohort of outpatients with permanent pacemakers. The prevalence and causes of left ventricular dysfunction (LVD) were explored.

Methods

In total, 1869 patients of a pacemaker outpatient clinic were screened for left ventricular systolic dysfunction by transthoracic echocardiography. All patients were interviewed for symptoms and cardiologist care. Percentages of RV pacing and underlying cardiac disease were recorded.

Results

A left ventricular ejection fraction (LVEF) under 45% was found in 207 (11.1%) of all patients. Predictive factors for a reduced LVEF were a high pacing rate and long-term pacing. LVD due to RV pacing was diagnosed in 3.4% of all patients. Only 845 patients (45%) reported that they regularly visited a cardiologist.

Conclusion

There is a high prevalence of unknown LVD in a typical pacemaker cohort. Therefore, regular echocardiographic examinations should be performed in outpatients of pacemaker clinics.

Clinical features, predictors, and long-term prognosis of pacing-induced cardiomyopathy

AIMS

We investigated the clinical features, predictors, and long-term prognosis of pacing-induced cardiomyopathy (PiCM).

METHODS AND RESULTS

From a retrospective analysis of 1418 consecutive pacemaker patients, 618 were found to have a preserved baseline left ventricular ejection fraction (LVEF), follow-up echocardiographic data, and no history of heart failure (HF). PiCM was defined as a reduction in LVEF (< 50%) along with either (i) a ≥ 10% decrease in LVEF, or (ii) new-onset regional wall motion abnormality unrelated to coronary artery disease. PiCM occurred in 87 of 618 patients (14.1%), with a decrease in mean LVEF from 60.5% to 40.1%. The median time to PiCM was 4.7 years. Baseline left bundle branch block, wider paced QRS duration (≥ 155 ms), and higher ventricular pacing percentage (≥ 86%) were identified as independent predictors of PiCM in multivariate logistic regression analysis. The risk of PiCM increased gradually with the number of identified predictors, becoming more significant in the presence of two or more predictors (P < 0.001). During the entire follow-up (median 7.2 years), the risk of all-cause death or HF admission was significantly higher in patients with PiCM compared to those without PiCM (38.3% vs. 54.0%, adjusted hazard ratio 2.93; 95% confidence interval 1.82-4.72; P < 0.001).

CONCLUSION

Pacing-induced cardiomyopathy patients showed a worse long-term prognosis than those without PiCM. Therefore, patients with multiple risk factors of PiCM should be monitored carefully even if their left ventricular systolic function is preserved initially. A timely upgrade to a biventricular or His-bundle pacing device needs to be considered in patients with PiCM.