Prognostic factors of pacing-induced cardiomyopathy

Incidence, Risk Factors, and Outcomes of Left Atrial Enlargement in Patients Requiring Right Ventricular Pacing: A Retrospective Study of 461 Cases from 2012 to 2020

BACKGROUND Long-term right ventricular (RV) pacing has been linked to left atrial enlargement (LAE). The incidence and risk factors associated with significant LAE after RV pacing remain unknown. This retrospective study included 461 patients requiring RV pacing at 2 centers between 2012 and 2020 and aimed to evaluate the incidence, risk factors, outcomes, and complications of LAE. MATERIAL AND METHODS A total of 461 patients with normal-sized pre-implant left atrial dimension and dual-chamber pacing pacemaker implantation for complete atrioventricular block were enrolled. Patients were grouped based on a ≥20% increase from their baseline left atrial dimension by echocardiography, indicating significant LAE, and initial characteristics, echocardiographic data, and outcomes were compared. RESULTS During a mean 7.0±4.9 years follow-up period, 96 patients (20.8%) developed significant LAE, whereas 365 patients did not. In multivariate logistic regression analysis, smaller pre-implant left atrial dimension (OR, 0.776; 95% CI, 0.728-0.828; P<0.001), lower post-implant left ventricular ejection fraction (OR, 0.976; 95% CI, 0.957-0.995; P=0.014), post-implant development of moderate to severe mitral regurgitation (OR, 2.357; 95% CI, 1.172-4.740; P=0.016), and RV pacing duration ≥3.3 years (OR, 1.576; 95% CI, 1.039-2.646; P=0.045) were independent predictors of significant LAE after RV-dependent pacing. There was a significant difference in the incident stroke events between patients without and with significant LAE (9.9% vs 17.7%; log-rank P=0.047). CONCLUSIONS Long-term RV pacing was linked to significant LAE in 20.8% of patients with complete atrioventricular block, with those affected experiencing a higher stroke rate during follow-up.

Optimizing Patient Selection for Physiological Pacing in Bradyarrhythmia: Factors Associated With High Ventricular Pacing Burden

Background

Right ventricular (RV) pacing is established as the most common ventricular pacing (VP) strategy for patients with symptomatic bradyarrhythmia. Some patients with high VP burden suffer deterioration of left ventricular (LV) function, termed pacing-induced cardiomyopathy (PICM). Patients who pace > 20% of the time from the RV apex are at increased risk of PICM, but independent predictors of increased RV pacing burden have not been elucidated in those who have a permanent pacemaker (PPM) inserted for bradyarrhythmia.

Methods

We aimed to identify factors that are associated with increased VP burden > 20%, hence determining those at risk for resultant PICM. In this retrospective cohort study, we identified the most recent 300 consecutive cardiac implantable electronic device (CIED) implants in our center and collected past medical history, electrocardiogram (ECG), echo, medication and pacemaker check data.

Results

A total of 236 individuals met inclusion criteria. Of the patients, 35% had RV pacing burden < 20%, while 65% had VP burden ≥ 20%; 96.2% of patients with complete heart block (CHB) paced > 20% (P = 0.002). Utilization of DDD or VVI (75.2% and 89.2% of patients, respectively) without mode switch algorithms was associated with VP > 20% (P < 0.001). Male or previous coronary artery bypass grafting (CABG) patients also statistically paced > 20%. Other factors trending towards significance included prolonged PR interval, atrial fibrillation or more advanced age.

Conclusion

High-grade atrioventricular (AV) block was associated with an RV pacing burden > 20% over 3 years but this was not consistent in patients with only transient episodes of high-grade AV block. We found a significant association between high VP% and male sex, previous CABG and the absence of mode switching algorithms.

Pacing-Induced Cardiomyopathy in Leadless and Traditional Pacemakers: A Single-Center Retrospective Analysis

BACKGROUND

 Pacing-induced cardiomyopathy (PICM) is a clinical syndrome that is characterized by a drop in the left ventricular ejection fraction (LVEF) due to chronic high-burden right ventricular (RV) pacing. It has been postulated that leadless pacemakers (LPs) cause decreased risk of PICM compared to transvenous pacemakers (TVPs), but the exact risk reduction is unknown.

METHODS

We performed a single-center retrospective analysis of adults who received an LP or TVP between January 1, 2014, and April 1, 2022, and had echocardiograms before and after the pacemaker implant. This study's outcomes were the RV pacing percentage, change in EF, the need for cardiac resynchronization therapy (CRT) upgrade, and follow-up duration. A Wilcoxon rank-sum test calculated the change in EF. RV time, defined as the duration from pacemaker placement to the follow-up echocardiogram in months multiplied by the RV pacing percentage, served as a surrogate for how long the RV was paced.

RESULTS

A total of 614 patients were screened, and 198 patients were included in the study, where 72 received LP and 126 received TVP. The median follow-up was 480 days. The average of the reported RV percentage pacing was 63.43% for LP and 71.30% for TVP (p=0.14). The incidence of PICM and CRT upgrade was 44% and 9.7% in the LP group and 37% and 9.5% in the TVP group (p=0.3 and p>0.9), respectively. After accounting for age, sex, LP versus TVP, atrioventricular nodal ablation, RV pacing percentage, and follow-up duration, univariate analysis showed that RV time was significantly different between the two types of pacemakers (13.54 ± 14.21 months (LP) versus 9.26 ± 13.95 months (TVP), p=0.009). The difference in RV time between patients who underwent CRT upgrade and those who did not was statistically insignificant (12.11 ± 14.47 months (no CRT) versus 9.19 ± 12.00 months (CRT), p=0.5).

CONCLUSIONS

This analysis demonstrated that the incidence of PICM was high in both groups (44% (LP) versus 37% (TVP)), despite significantly more RV time in patients with LP. There was no difference in CRT upgrade between LP and TVP.

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.

Impact of right ventricular lead position on left ventricular functions and early remodeling in permanent single- and dual-chamber pacemakers

BACKGROUND

Right ventricular (RV) apical pacing can induce both interventricular dyssynchrony and intraventricular dyssynchrony. Mechanical dyssynchrony after long-term RV apical pacing is associated with reduced left ventricular (LV) systolic function and deterioration in functional capacity.

AIM

We aimed to identify the short-term effects of the pacemaker RV lead position on remodeling of LV systolic functions.

PATIENTS AND METHODS

The study included 30 patients who presented with an indication of permanent pacing and who underwent permanent single- or dual-chamber pacemaker insertion: 15 patients with RV apical pacing (RV apex), and 15 patients with non-apical pacing (mid-septal). The two-dimensional (2D) speckle tracking imaging technique was used for quantification of global longitudinal function of the left ventricle and dyssynchrony evaluation before pacemaker implantation and after a 3-month follow-up.

RESULTS

At the 3‑month follow-up, post-pacing 2D speckle tracking echocardiography revealed impairment of global longitudinal strain in all patients and intraventricular dyssynchrony was significantly increased in the apical location compared with the non-apical location (radial dyssynchrony: 108.67 ± 11.68 ms vs. 80.53 ± 8.17 ms, p < 0.001) with a greater difference (50.53 ± 13.30 ms) in the apical location than in the non-apical location (29.87 ± 6.64 ms, p < 0.001).

CONCLUSION

In the short-term follow-up, 2D speckle tracking echocardiography showed more radial dyssynchrony in the apical location than in the non-apical location of RV lead. The RV septal pacing is a better alternative in terms of less dyssynchrony compared to RV apical pacing. Older age, higher percentage of pacing, and device type are prognostic factors for development of pacemaker-induced cardiomyopathy.

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.