Long-term survival after permanent pacemaker implantation: analysis of predictors for increased mortality

The impact of permanent pacemaker implantation on long-term survival after cardiac surgery: A systematic review and meta-analysis

OBJECTIVES

The long-term impact of permanent pacemaker (PPM) implantation on survival after cardiac surgery remains ill defined. We aimed to investigate the effect of PPM on survival and explore factors driving outcomes using meta-regression according to the type of surgery.

METHODS

MEDLINE, EMBASE, and the Cochrane Library Central Register of Controlled Trials were searched through October 2023 to identify studies reporting the long-term outcomes of PPM implantation. The primary outcome was all-cause mortality during follow-up. The secondary outcome was heart failure rehospitalization. The subgroup analysis and meta-regression analysis were performed according to the type of surgery.

RESULTS

A total of 28 studies met the inclusion criteria. 183,555 patients (n = 6298; PPM, n = 177,257; no PPM) were analyzed for all-cause mortality, with a weighted median follow-up of 79.7 months. PPM implantation was associated with increased risks of all-cause mortality during follow-up (hazard ratio, 1.22; confidence interval, 1.08-1.38, P < .01) and heart failure rehospitalization (hazard ratio, 1.24; confidence interval, 1.01-1.52, P = .04). Meta-regression demonstrated the adverse impact of PPM was less prominent in patients undergoing mitral or tricuspid valve surgery, whereas studies with a greater proportion with aortic valve replacement were associated with worse outcomes. Similarly, a greater proportion with atrioventricular block as an indication of PPM was associated with worse survival.

CONCLUSIONS

PPM implantation after cardiac surgery is associated with a greater risk of long-term all-cause mortality and heart failure rehospitalization. This impact is more prominent in patients undergoing aortic valve surgery or atrioventricular block as an indication than those undergoing mitral or tricuspid valve surgery.

Leadless or Conventional Transvenous Ventricular Permanent Pacemakers: A Nationwide Matched Control Study

Background

Leadless ventricular permanent pacemakers (leadless VVI or LPM) were designed to reduce lead‐related complications of conventional VVI pacemakers (CPM). The aim of our study was to assess and compare real‐life clinical outcomes within the first 30 days and during a midterm follow‐up with the 2 techniques.

Methods and Results

This French longitudinal cohort study was based on the national hospitalization database. All adults (age ≥18 years) hospitalized in French hospitals from January 1, 2017 to September 1, 2020, who underwent a first LPM or CPM were included. The study included 40 828 patients with CPM and 1487 with LPM. After propensity score matching 1344 patients with CPM were matched 1:1 with patients treated with LPM. Patients with LPM had a lower rate of all‐cause and cardiovascular death within the 30 days after implantation. During subsequent follow‐up (mean: 8.6±10.5 months), risk of all‐cause death in the unmatched population was significantly higher in the LPM group than in the CPM group, whereas risk of cardiovascular death and of endocarditis was not significantly different. After matching on all baseline characteristics including comorbidities (mean follow‐up 6.2±8.7 months), all‐cause death, cardiovascular death, and infective endocarditis were not statistically different in the 2 groups.

Conclusions

Patients treated with leadless VVI pacemakers had better clinical outcomes in the first month compared with the patients treated with conventional VVI pacing. During a midterm follow‐up, risk of all‐cause death, cardiovascular death, and endocarditis in patients treated with leadless VVI pacemaker was not statistically different after propensity score matching.

Clinical outcomes and predictors of complications in patients undergoing leadless pacemaker implantation

BACKGROUND

Leadless pacemakers have emerged as a viable alternative for traditional transvenous pacemakers to reduce the risk of device-related complications.

OBJECTIVE

The purpose of this study was to examine the real-world clinical outcomes and complications associated with the implantation of leadless pacemaker devices.

METHODS

Using the National Readmission Database (NRD), we examined patient demographics, and in-hospital and 30-day procedural outcomes after leadless pacemaker implantation from 2016-2018. Our cohort comprised adults (≥18 years) with an ICD-10 procedural code for leadless pacemaker implantation.

RESULTS

Our cohort included a total of 7821 patients who underwent leadless pacemaker implantation. Overall immediate procedure-related complications, as defined broadly in this study, occurred in 7.5% of patients. Pericardial effusion without the need for pericardiocentesis occurred in 1.9% of patients, with pericardiocentesis performed in 1.0%. Vascular complications occurred in 2.3% of patients; 0.33% required repair, and device dislodgment occurred in 0.51%. The most significant predictor for procedural complications was end-stage renal disease (odds ratio [OR] 1.65; 95% confidence interval [CI] 1.17-2.32; P = .004), congestive heart failure (OR 1.28; 95% CI 1.01-1.62; P = .04), and coagulopathy (OR 1.77; 95% CI 1.34-2.34; P <.001). All-cause readmission occurred in 17.9% of patients within 30 days from device implant, with 1.36% of readmissions being procedure related. At 30 days postimplant and after discharge, 0.25% of patients needed a new pacemaker, and 0.18% had pericardial complications.

CONCLUSION

In our large real-life cohort, we found the rate of serious complications after leadless pacemaker implantation to be relatively low and comparable to prior studies in a high-risk population with multiple comorbid conditions.

Etiology of chronic atrioventricular block in young adults in a public university hospital in India

In young adults, chronic atrioventricular (AV) block has scant systematic documentation in India. This prospective study included patients 18–40 years old, presenting with AV block without a reversible cause. There were 27 patients, aged 32 +/- 6.3 years, with 16 males. All patients had complete AV block with a narrow QRS escape rhythm (rate 40.5 ± 6.5 beats/min). Three patients were ANA positive and of these, 2 patients were anti ds DNA positive. The ESR and CRP levels were mildly elevated in 12 and 8 patients respectively. The rest of the tests were unremarkable. Despite performing multiple tests, the etiology remained idiopathic in most.

Etiology and device therapy in complete atrioventricular block in pediatric and young adult population: Contemporary review and new perspectives

Complete atrioventricular block (CAVB) is a total dissociation between the atrial and ventricular activity, in the absence of atrioventricular conduction. Several diseases may result in CAVB in the pediatric and young-adult population. Permanent right ventricular (RV) pacing is required in permanent CAVB, when the cause is neither transient nor reversible. Continuous RV apical pacing has been associated with unfavorable outcomes in several studies due to the associated ventricular dyssynchrony. This study aims to summarize the current literature regarding CAVB in the pediatric and young adult population and to explore future treatment perspectives.

Sex differences in Cardiac electronic device implantation: Outcomes from an Australian multi-centre clinical quality registry

Background

There is uncertainty regarding whether outcomes after Cardiac Implantable Electronic Devices (CIED) differ between women and men. There are no prospectively collected data regarding Australian CIED outcomes. This study aimed to determine whether the characteristics and outcomes of Australian patients undergoing CIED implantation differ by sex.

Methods

We prospectively followed 5,360 patients undergoing CIED implantation between 2015 and 2019 in a large multi-centre Australian registry. Patient characteristics, procedural data, medications and clinical outcomes to 1 year were analysed.

Results

The mean age was 76.2 + 11.2 years, and 2022 (37.7%) were female. Women were older than men at device implantation (77.0 ± 11.6 years vs. 75.5 ± 10.9 years, p < 0.001). Most implants were de novo (79.7%). Pacing was more commonly for sick sinus syndrome in women than men (54.4% vs. 47.2%, p < 0.001) and less often for A-V block (28.3% vs. 35.1%, p < 0.001). Adverse events at 30 days were low compared to international cohorts, for mortality (0.06%) and major complications (0.6%). There were no significant sex differences (women vs. men) for death (HR 1.33, 95% CI 0.58–3.13, p = 0.49) or major complications (HR 1.41, 95% 95% CI 0.65–3.03, p = 0.39). At 1-year, there was no difference in major complications or risk-adjusted all-cause mortality (HR 1.05, 95% CI 0.70–1.29, p = 0.77) between women and men.

Conclusions

Clinical practice and 30-day outcomes after CIED implantation in Australia are consistent with international reports. There were no differences in procedural complication rates or clinical outcomes at 1-year between women and men, regardless of age or CIED system implanted.

Relation of Prolonged Pacemaker Dependency After Cardiac Surgery to Mortality

Permanent pacemaker implantation (PPI) represents a rare complication after cardiac surgery, with no uniform agreement on timing and no information on follow-up. A multicenter retrospective study was designed to assess pacemaker dependency (PMD) and long-term mortality after cardiac surgery procedures. Between 2004 and 2016, PPI-patients from 18 centers were followed. Time-to-event data were evaluated with semiparametric regression Cox models and semiparametric Fine and Gray model for competing risk framework. Of 859 (0.90%) PPI-patients, 30% were pacemaker independent (PMI) at 6 months. PMD showed higher mortality compared with PMI (10-year survival 80.1% ± 2.6% and 92.2% +2.4%, respectively, log-rank p-value < 0.001) with an unadjusted hazard ratio for death of 0.36 (95% CI 0.20 to 0.65, p< 0.001 favoring PMI) and an adjusted hazard ratio of 0.19 (95% CI 0.08 to 0.45, p< 0.001 with PMD as reference). Crude cumulative incidence function of restored PMI rhythm at follow-up at 6 months, 1 year and 12 years were 30.5% (95% CI 27.3% to 33.7%), 33.7% (95% CI 30.4% to 36.9%) and 37.2% (95% CI 33.8% to 40.6%) respectively. PMI was favored by preoperative sinus rhythm with normal conduction (SR) (HR 2.37, 95% CI 1.65 to 3.40, p< 0.001), whereas coronary artery bypass grafting and aortic valve replacement were independently associated with PMD (HR 0.63, 95% CI 0.45 to 0.88, p = 0.006 and HR 0.807, 95% CI 0.65 to 0.99, p = 0.047 respectively). Time-to-implantation was not associated with increased rate of PMI. Although 30% of PPI-patients are PMI after 6 months, PMD is associated with higher mortality at long term.

Sex Differences and Long-Term Outcome in Patients With Pacemakers

Introduction: Evidence of sex-related differences in patients with pacemakers regarding comorbidities is insufficiently investigated. The aim of this study was to determine the relationship of cardiovascular comorbidities and sex category with properties of pacemaker implantation, pacemaker follow-up, and long-term survival.

Methods: This retrospective, single-center cohort study consisted of 6,362 pacemaker-patients (39.7% female) enrolled between May 2000 and April 2015. Functional pacemaker parameters were registered at regular pacemaker controls. Survival status and cause of death were analyzed in relation to comorbidities, implanted pacing devices, and echocardiography. Survival analyses were plotted for a 10-year follow-up.

Results: Patients with hypertension or hyperlipidemia had higher rates of implantations due to sick sinus syndrome (28.6 vs. 25.5% without hypertension, P < 0.001; 30.7 vs. 25.7% without hyperlipidemia, P < 0.001), while endocarditis was associated with higher rates of implantations due to AV block (46.7 vs. 33.4%, P < 0.001). Patients with valvular heart disease had higher rates of pacemaker implantation due to bradycardic atrial fibrillation (24.9 vs. 21.0% without valvular heart disease, P < 0.001). Ventricular pacing threshold increased in both sexes during the follow-up and was higher in women in the final follow-up (0.94 vs. 0.91 V in men, P = 0.002). During the 10-years follow-up, 6.1% of women and 8.6% of men underwent lead replacement (P = 0.054). Device and lead replacement rates were increased if the comorbidities coronary artery disease, heart failure, hypertension, hyperlipidemia, valvular heart disease, previous stroke/TIA, atrial arrhythmias, chronic kidney disease, or endocarditis were present. Diabetes and previous CABG increase the rates of device replacement, but not the rate of lead replacement. Severe tricuspid regurgitation after implantation of pacemaker was present in more men than women (14.4 vs. 6.1%, P < 0.001). In a multivariate COX regression, the following variables were associated with independent decrease of 10-year survival: hypertension (HR 1.34, 95% CI 1.09–1.64), chronic kidney disease (HR 1.83, 95% CI 1.53–2.19), tricuspid regurgitation after pacemaker implantation (HR 1.48, 95% CI 1.26–1.74). Survival was independently increased in female sex (HR 0.83, 95% CI 0.70–0.99) and hyperlipidemia (HR 0.81, 95% CI 0.67–0.97).

Conclusions: Cardiovascular comorbidities influenced significantly pacemaker implantations and long-term outcome.

Trial Registration:ClinicalTrials.gov Unique identifier: NCT03388281.

Prognosis after pacemaker implantation in extreme elderly

AIMS

Significant comorbidities may limit the potential benefit of pacemaker (PM) implantation in extreme elderly. A short-term mortality risk prediction score, able to identify high-risk patients, may be a useful tool in this population.

METHODS AND RESULTS

We retrospectively analyzed 538 patients aged >80 years at the time of implant who underwent PM implantation. Kaplan-Meier survival and multivariable Cox regression analyses were performed to identify patient, procedural or complication variables predictive of death. The ACP (Aging in Cardiac Pacing) Score was constructed by assigning weighted values to the variables identified by hazard ratios, combined into an additive mortality risk score equation. One, two and three-year overall mortality rate was 11%, 21% and 32% respectively. Renal failure (HR 1.63; CI 1.15-2.31; p = .006), active neoplasia (HR 1.78; CI 1.27-2.51; p = .008), connective tissue disorder (3.07; CI 1.34-7.08; p = .048), cerebrovascular disease (HR 1.75; CI 1.25-2.46; p = .001) and the use of a single lead device (HR 2.27; CI 1.6-3.24; p < .001) were independently associated with worse survival. The ACP Score showed discrete predictive ability (AUC 0,6792 CI 0,63-0,73). Kaplan-Meier survival curves comparing low vs high ACP Scores demonstrated that low ACP scores were associated with reduced mortality rates (p < .001).

CONCLUSIONS

Significant comorbidities were associated with worse survival after PM implantation in extreme elderly. The ACP Score is a novel tool that may help to identify patients with high mortality risk after device implantation.

Design and evaluation of the Micra Transcatheter Pacing System for bradyarrhythmia management

Permanent cardiac pacemakers have traditionally comprised a surgically implanted subcutaneous pulse generator affixed to at least one transvenous pacing lead. Despite technological advances, implant-related complications and transvenous-lead failure rates have remained high. The Micra Transcatheter Pacing System is a miniaturized single chamber pacemaker that is implanted directly into the right ventricle, eliminating the subcutaneous pocket and creating a leadless pacemaker system. Registry data show an extremely high implant success rate, significantly lower major complication rates than transvenous pacemakers, stable pacing parameters and reliable battery performance. In this review we summarize the available clinical literature and highlight the promising efficacy and safety of the Micra Transcatheter Pacing System.

Influence of permanent pacemaker implantation after transcatheter aortic valve implantation with new-generation devices

Objective

Permanent pacemaker implantation (PPMI) after transcatheter aortic valve implantation (TAVI) is the most common complication after the procedure. PPMI rates remain high with the new-generation TAVI devices despite improved outcomes concerning paravalvular aortic regurgitation and vascular access complications. However, the impact of PPMI on mortality and clinical outcome is still a matter of debate, and data with new-generation devices on this matter are scarce. Therefore, we sought to analyse the influence of PPMI in patients treated with the new-generation devices on one-year outcome.

Methods

We enrolled 612 consecutive patients without prior pacemaker undergoing transfemoral TAVI with the new-generation devices. Patients with or without PPMI were compared with respect to clinical outcome within one year.

Results

PPMI was performed in 168 patients (24.4% of the overall study population). There was no significant difference in one-year outcome concerning all-cause mortality (PPMI vs. no-PPMI: 12.2% vs. 12.5%, p = 0.94), rate of major adverse events including cardiac, cerebral or valve-related events and bleeding complications (22.1% vs. 24.5%, p = 0.55) or need for rehospitalisation due to cardiac symptoms (16.1% vs. 18.1%, p = 0.63). In patients with reduced ejection fraction (<45%) there was also no impact of PPMI on one-year mortality (14.3% vs. 15.7%, p = 0.86). Furthermore, multivariate analysis did not reveal PPMI to be independently associated with one-year mortality (odds ratio 0.94, 95% confidence interval 0.50–1.74, p = 0.83).

Conclusions

In this large all-comers TAVI population with new-generation devices the need for postprocedural PPMI did not show a statistical significant impact on survival or combined endpoint of major adverse events within one year.

Association of selected factors with long-term prognosis and mortality after dual-chamber pacemaker implant

BACKGROUND

Dual-chamber (DDD) pacing is the most widely utilised pacing modality in many parts of the world. The present study aimed to evaluate life expectancy of DDD pacemaker patients in comparison to the age- and sex-matched general population, assess changes in baseline characteristics over three decades of the inclusion period and determine the association between selected variables and patient survival.

METHODS

This longitudinal study of consecutive de novo DDD pacemaker implantations performed between 1984 and 2014, with all-cause mortality until 2016 as the endpoint, was conducted at a singlecenter university hospital.

RESULTS

Under assessment were 3928 patients with a total of 30,087 patient-years of survival time. Compared to the general population, the observed survival was significantly inferior until 12 years post DDD pacemaker implant (HR = 1.499, p < 0.001), whereas after 12 years of follow-up the observed survival was significantly superior (HR = 0.555, p < 0.001). A comparison of patient baseline characteristics over three decades revealed the following significant changes: more elderly patients, more female patients, less patients with atrioventricular block, more patients with atrial fibrillation/atrial flutter (AF/AFL) and fewer patients with an apical right ventricular (RV) lead position in the later decades. In multivariate analysis male sex and higher age were the only variables significantly associated with shorter survival time. Indication for pacing, history of pre-implant AF/AFL, RV lead position and device infection were not associated with survival.

CONCLUSIONS

In the very-long-term follow-up of DDD pacemaker patients, the parameters associated with survival were sex and baseline age at first implantation.

Updated performance of the Micra transcatheter pacemaker in the real-world setting: A comparison to the investigational study and a transvenous historical control

BACKGROUND

Early results of the Micra Investigational Device Exemption (IDE) study and Micra Post-Approval Registry (PAR) demonstrated excellent safety and efficacy performance; however, intermediate-term results across a large patient population in the real-world setting have not been evaluated.

OBJECTIVES

We report updated performance of the Micra transcatheter pacemaker from a worldwide PAR and compare it with the IDE study as well as a transvenous historical control.

METHODS

The safety objective of the analysis was system- or procedure-related major complications through 12 months postimplantation. We compared the major complication rate with that of the 726 patients from the IDE and with a reference data set of 2667 patients with transvenous pacemakers by using a Fine-Gray competing risk model.

RESULTS

The Micra device was successfully implanted in 1801 of 1817 patients (99.1%). The mean follow-up period was 6.8 ± 6.9 months. Through 12 months, the major complication rate was 2.7% (95% confidence interval [CI] 2.0%-3.7%). The risk of major complications for Micra PAR patients was 63% lower than that for patients with transvenous pacemakers through 12 months postimplantation (hazard ratio 0.37; 95% CI 0.27-0.52; P < .001). The major complication rate trended lower in the PAR than in the IDE study (hazard ratio 0.71; 95% CI 0.44-1.1; P = .160), driven by the lower pericardial effusion rate in the PAR. There were 3 cases of infection associated with the procedure, but none required device removal and there were no battery or telemetry issues. Pacing thresholds were low and stable through 12 months postimplantation.

CONCLUSION

Performance of the Micra transcatheter pacemaker in international clinical practice remains consistent with previously reported data. Major complications were infrequent and occurred 63% less often compared to transvenous systems.

CLINICAL TRIAL REGISTRATION

Micra Transcatheter Pacing System Post-Approval Registry ClinicalTrials.gov identifier: NCT02536118; Micra Transcatheter Pacing Study ClinicalTrials.gov identifier: NCT02004873.

Prognosis of patients with implanted pacemakers in 4‑year follow-up : Impact of right ventricular pacing site

BACKGROUND

Pacing remains the method of choice for treatment of cardiac electrical conduction disorders. This study examined the interrelationship between the site of the right ventricular lead tip and patient prognosis in association with other cardiovascular risk factors over a 4‑year follow-up period.

PATIENTS AND METHODS

The study comprised 450 consecutive patients (223 women; aged 69.16 ± 9.63 years) who had their first SSI or DDD pacemaker implanted for typical indications.

RESULTS

During follow-up, 91 (20.2%) patients died. The positive prognostic factors were: female sex (hazard ratio [HR] = 0.426), DDD pacemaker (HR = 0.526), oral anticoagulant use (HR = 0.330; all groups), sodium concentration (HR = 0.926), oral anticoagulant (HR = 0.115) and statin (HR = 0.260) use (female group), and non-apical location of the right ventricular lead tip (HR = 0.549; male group). Risk factors for death were: age (HR = 1.063), diabetes requiring insulin (HR = 2.832), creatinine concentration (HR = 1.005; all groups), age (HR = 1.11; female group), and elevated creatinine level (HR = 1.012; male group). In all patients, the non-apical location of the right ventricular lead tip was associated with an 18.92% reduced mortality rate during the 4‑year follow-up, which was statistically significant for the male group.

CONCLUSION

The non-apical location of the right ventricular lead tip was a positive prognostic factor and was statistically significant in the male subgroup.

"I'm Not Sure We Had A Choice": Decision Quality and The Use of Cardiac Implantable Electronic Devices In Older Adults With Cognitive Impairment

Background

The decision to implant a cardiac device in a person with Alzheimer’s disease or related dementia requires considering the possible trade-offs of quality of life (QOL) and quantity of life. This study measured the decision-making experience of patients with and without cognitive impairment (CI) who received a cardiac device and their family members who were involved in the decision.

Methods and Results

Semi-structured interviews and questionnaires were administered with 15 patient-family member dyads. Interviews revealed few conversations between physicians, patients and family members about the patient’s cognitive status or about the benefits, risks, and long-term implications of the device for someone with CI. Participants largely stated that the decision to get the device was based on the patient’s functional status at the time of the implant, and not on expectations about future functioning. Patients with CI had more regret, measured with the Decision Regret Scale (DRS), (p=0.037) and family members of patients without CI reported more decisional conflict, measured with the Decisional Conflict Scale (p=0.057).

Conclusions

Although CI impacts life expectancy and QOL, cognitive status was largely not discussed prior to device implant. Few differences were found between the experiences of dyads that included patients with or without CI.

Implant of permanent pacemaker during acute coronary syndrome: Mortality and associated factors in the ARIAM registry

BACKGROUND

Patients with acute coronary syndrome complicated with high degree atrioventricular block still have a high mortality. A low percentage of these patients need a permanent pacemaker (PPM) but mortality and associated factors with the PPM implant in acute coronary syndrome patients are not known. We assess whether PPM implant is an independent variable in the mortality of acute coronary syndrome patients. Also, we explored the variables that remain independently associated with PPM implantation.

METHODS

This was an observational study on the Spanish ARIAM register. The inclusion period was from January 2001 to December 2011. This registry included all Andalusian acute coronary syndrome patients. Follow-up for global mortality was until November 2013.

RESULTS

We selected 27,608 cases. In 62 patients a PPM was implanted (0.024%). The mean age in PPM patients was 70.71±11.214 years versus 64.46±12.985 years in patients with no PPM. PPM implant was associated independently with age (odds ratio (OR) 1.031, 95% confidence interval (CI) 1.007-1.055), with left ventricular branch block (OR 6.622, 95% CI 2.439-18.181), with any arrhythmia at intensive care unit admission (OR 2.754, 95% CI 1.506-5.025) and with heart failure (OR 3.344, 95% CI 1.78-8.333). PPM implant was independently associated with mortality (OR 11.436, 95% CI 1.576-83.009). In propensity score analysis PPM implant was still associated with mortality (OR 5.79, 95% CI 3.27-25.63).

CONCLUSION

PPM implant is associated with mortality in the acute coronary syndrome population in the ARIAM registry. Advanced age, heart failure, arrhythmias and left ventricular branch block at intensive care unit admission were found associated factors with PPM implant in acute coronary syndrome patient.

Impact of prior permanent pacemaker on long-term clinical outcomes of patients undergoing percutaneous coronary intervention

BACKGROUND

The impact of permanent pacemaker (PPM) on long-term clinical outcomes of patients undergoing percutaneous coronary intervention (PCI) has not been studied.

HYPOTHESIS

PPM may increase heart failure (HF) burden on patients undergoing PCI.

METHODS

We recruited consecutive patients undergoing PCI and carried out a nested case-control study. Patients with confirmed PPM undergoing first PCI were identified and matched by age and sex in 1:1 fashion to patients without PPM undergoing first PCI. Clinical data were collected and analyzed. The primary endpoint outcomes were all-cause mortality and hospitalization for HF.

RESULTS

The final analysis included 156 patients. The mean follow-up period was 4.6 ± 2.9 years. The overall all-cause mortality was 21.15%, without significant difference between the 2 groups (21.79% vs 20.51%; P = 0.85). However, the rate of HF-related hospitalization was significantly higher in patients with PPM than in controls (26.92% vs 10.26%; P = 0.008). After adjustment for hypertension, type 2 diabetes mellitus, hyperlipidemia, chronic kidney disease, stroke, left ventricular ejection fraction, brain natriuretic peptide, and acute coronary syndrome (ACS), PCI patients with PPM were still associated with a greater hospitalization rate for HF (odds ratio: 4.31, 95% confidence interval: 0.94-19.80, P = 0.061). Further analysis in the ACS subgroup showed VVI-mode pacing enhanced the risk for HF-associated hospitalization (adjusted odds ratio: 8.27, 95% confidence interval: 1.37-49.75, P = 0.02).

CONCLUSIONS

PPM has no effect on all-cause mortality in patients undergoing first PCI but significantly increases the HF-associated hospitalization rate, especially in ACS patients.

Impact of sex and ethnicity on arrhythmic risk

Substantial differences in the risk of common arrhythmia syndromes exist between men and women, as well as in varying ethnic/racial groups. For example, despite an overall lower risk of sudden death and atrial fibrillation in women compared with men, women have longer QT intervals and a higher risk of torsades de pointes due to antiarrhythmic drugs and worse outcomes associated with atrial fibrillation. An ethnicity-related paradox in atrial fibrillation epidemiology is apparent; despite a higher prevalence of medical comorbidities such as hypertension, diabetes, and prolonged PR interval, blacks, Hispanics, and Asians have a lower risk of atrial fibrillation than whites. In this promising era of genomic medicine, an improved understanding of epidemiology and phenotype holds the potential for revealing novel therapeutic targets and preventing disease.

Outcomes in Women Undergoing Electrophysiological Procedures

The number of invasive electrophysiological procedures is steadily increasing in Western countries, as the age of the population increases and technologies advance. In recent years, gender-related differences in cardiac rhythm disorders have been increasingly appreciated, which can potentially have a great impact on the outcomes of invasive electrophysiological procedures. Among supraventricular arrhythmias, women have a higher incidence of atrioventricular nodal re-entrant tachycardia and a significantly lower incidence of atrioventricular re-entrant tachycardia compared with males, and present to ablation procedures later and after having failed more antiarrhythmic drugs. The results of catheter ablation of atrial fibrillation in women have been reported worse than in men. This finding is possibly due to a later referral of females to ablation procedures, who present older and with a higher incidence of long-standing persistent atrial fibrillation. With regard to cardiac device implantation procedures, a smaller survival benefit from prophylactic implantable cardioverter defibrillator (ICD) implantation has been shown in women, essentially due to gender-specific differences in the clinical course of patients with severe left ventricular dysfunction, with women dying predominantly from non-arrhythmic causes. On the other side, the clinical outcome of cardiac resynchronisation therapy seems to be more favourable in women, who experience a greater degree of reverse left ventricular remodelling and a striking decrease of heart failure events or mortality after biventricular pacing. This review will summarise the available evidence on gender-related differences in outcomes of invasive electrophysiological procedures.

Ten-year Survival and Its Associated Factors in the Patients Undergoing Pacemaker Implantation in Hospitals Affiliated to Shiraz University of Medical Sciences During 2002 - 2012

Background:

Heart failure is a prevalent disease affecting about 4.9 million people in the U.S. and more than 22 million individuals worldwide. Using electric pacemaker is the most common treatment for the patients with heart conduction problems. The present study aimed to determine the factors affecting survival in the patients undergoing pacemaker implantation in the hospitals affiliated to Shiraz University of Medical Sciences.

Objectives:

The aim of the present study was to identify the factors affecting the survival of the patients suffering from arrhythmia.

Patients and Methods:

This retrospective survival analysis was conducted on all 1207 patients with heart failure who had undergone permanent pacemaker implantation in the hospitals affiliated to Shiraz University of Medical Sciences from 2002 to 2012. The data were analyzed using non-parametric methods such as Kaplan-Meier method, life table, and Cox regression model. The risk factors of mortality were determined using multivariate Cox proportional hazards method.

Results:

Survival data were available for 1030 (80%) patients (median age = 71 years [5th to 95th percentile range: 26 - 86 years]) and follow-up was completed for 84.28% of them. According to the results, 56% of the patients had received dual-chamber systems, while 44% had been implanted by single-chamber ventricular systems. Moreover, sick sinus syndrome and pacemaker mode were independent predictors of increased mortality.

Conclusions:

In this study, sick sinus syndrome and pacemaker mode followed by syncope were independently associated with increased mortality.

Mortality in patients on renal replacement therapy and permanent cardiac pacemakers

End stage renal disease is a relatively frequent disease with high mortality due to cardiac causes. Permanent pacemaker (PM) implantation rates are also very common; thus combination of both conditions is not unusual. We hypothesized that patients with chronic kidney disease with a PM would have significantly higher mortality rates compared with end stage renal disease patients without PM. Our objectives were to analyze mortality of patients on renal replacement therapy with PM. 2778 patients were on renal replacement therapy (RRT) and 110 had a PM implanted during the study period. To reduce the confounding effects of covariates, a propensity-matched score was performed. 52 PM patients and 208 non-PM matched patients were compared. 41% of the PM were implanted before entering the RRT program and 59% while on RRT. Mortality was higher in the PM group. Cardiovascular disease and infections were the most frequent causes of death. Propensity analysis showed no differences in long-term mortality between groups. We concluded that in patients on RRT and PM mortality rates are higher. Survival curves did not differ from a RRT propensity-matched group. We concluded that the presence of a PM is not an independent mortality risk factor in RRT patients.

Long-term prognosis of patients older than ninety years after permanent pacemaker implantation: does the procedure save the patients?

BACKGROUND

The implantation of a permanent pacemaker (PPM) is life-saving for patients with life-threatening bradycardia. However, the effectiveness and prognosis of PPM implantations for extremely old patients (≥ 90 years old) have not been investigated.

METHODS

From 2001-2012, a total of 108 patients older than 90 years were identified from 2630 consecutive patients receiving PPM implantations in our hospital as the study group. For each study patient, 4 age-, sex-, and comorbidity-matched subjects who did not have the diagnoses of bradyarrhythmias indicated for PPM implantations were selected from the "Taiwan National Health Research Database" to constitute the control group (n = 432). The study end point was all-cause mortality.

RESULTS

The median age of the study population was 91 (interquartile range, 90-93) years. Among the PPM group, 45 patients died during the follow-up with an annual mortality rate of 18.7%. The risk of mortality did not differ significantly between the study and control groups with a hazard ratio of 1.020 (95% confidence interval, 0.724-1.437; P = 0.912) after the adjustment for age and sex. Procedure-related complications occurred in 7.4% of the patients receiving PPM implants, and pocket hematoma was the most common. The preimplantation history of heart failure and cerebrovascular accident, rather than age, were significant predictors of mortality among PPM recipients.

CONCLUSIONS

Nonagenarians with severe bradyarrhythmias could retain the same life expectancies as those without bradyarrhythmias through PPM implantations. Extremely old age (≥90 years) should not be a barrier for PPM implants when indications are present.

Permanent pacemaker implantation after transcatheter aortic valve implantation: impact on late clinical outcomes and left ventricular function

BACKGROUND

Very few data exist on the clinical impact of permanent pacemaker implantation (PPI) after transcatheter aortic valve implantation. The objective of this study was to assess the impact of PPI after transcatheter aortic valve implantation on late outcomes in a large cohort of patients.

METHODS AND RESULTS

A total of 1556 consecutive patients without prior PPI undergoing transcatheter aortic valve implantation were included. Of them, 239 patients (15.4%) required a PPI within the first 30 days after transcatheter aortic valve implantation. At a mean follow-up of 22±17 months, no association was observed between the need for 30-day PPI and all-cause mortality (hazard ratio, 0.98; 95% confidence interval, 0.74-1.30; P=0.871), cardiovascular mortality (hazard ratio, 0.81; 95% confidence interval, 0.56-1.17; P=0.270), and all-cause mortality or rehospitalization for heart failure (hazard ratio, 1.00; 95% confidence interval, 0.77-1.30; P=0.980). A lower rate of unexpected (sudden or unknown) death was observed in patients with PPI (hazard ratio, 0.31; 95% confidence interval, 0.11-0.85; P=0.023). Patients with new PPI showed a poorer evolution of left ventricular ejection fraction over time (P=0.017), and new PPI was an independent predictor of left ventricular ejection fraction decrease at the 6- to 12-month follow-up (estimated coefficient, -2.26; 95% confidence interval, -4.07 to -0.44; P=0.013; R(2)=0.121).

CONCLUSIONS

The need for PPI was a frequent complication of transcatheter aortic valve implantation, but it was not associated with any increase in overall or cardiovascular death or rehospitalization for heart failure after a mean follow-up of ≈2 years. Indeed, 30-day PPI was a protective factor for the occurrence of unexpected (sudden or unknown) death. However, new PPI did have a negative effect on left ventricular function over time.

Outcome of invasive electrophysiological procedures and gender: are males and females the same?

The aim of this review is to summarize the available evidence on gender-related differences in outcome of invasive electrophysiological procedures. Gender exerts significant influences on the epidemiology, pathophysiology, and clinical presentation of many cardiac rhythm disorders. Women with supraventricular arrhythmias have a higher incidence of atrioventricular nodal reentrant tachycardia, a lower prevalence of atrioventricular accessory pathways, and increased arrhythmia inducibility during luteal phases of the menstrual cycle. Catheter ablation of supraventricular arrhythmias appears equally effective in the 2 genders, although women present to catheter ablation later, with more symptoms, and after having failed more antiarrhythmic drugs. The outcome of catheter ablation of atrial fibrillation in women has been reported worse than in men, which may be explained by a later referral. Accordingly, women present to catheter ablation with a higher incidence of long-standing persistent atrial fibrillation. Of note, the outcome of catheter ablation of atrial flutter does not seem to differ between genders. To date, with regard to ventricular arrhythmias, no gender-related differences in outcome of catheter ablation procedures have been reported. However, pathophysiology and risk factors underlying ventricular arrhythmias appear different in the two genders. Severe left ventricular dysfunction does not perform equally as a predictor for sudden cardiac death in women as compared to men, and the survival benefit of prophylactic implantable cardioverter-defibrillator (ICD) implantation in women is inconclusive. On the other hand, the clinical outcome after cardiac resynchronization therapy seems to be more favorable in women, who experience a greater degree of reverse left ventricular remodeling.

Reuse of pacemakers and defibrillators in developing countries: logistical, legal, and ethical barriers and solutions

In the wealthy nations of the world, access to implantable cardiac rhythm management devices is widespread. In many underserved low- and middle-income countries (LMIC), where cardiovascular disease is fast becoming a major public health problem, access is often limited. Reuse of pulse generators was practiced regularly in some European nations in the 1990s with good results. It is performed in LMIC, although the rates of device reuse are unknown. The available literature suggests there is no increased risk of morbidity or mortality with the reuse of devices. Donations of pacemaker and defibrillator pulse generators from developed nations constitute an important source of devices for the poor in LMIC. There are opportunities to increase this supply, but logistical barriers and legal and ethical concerns must be addressed. With proper sterilization, meticulous chains of custody, and advance directives for device handling (pacemaker/defibrillator living wills), patients in LMIC who would otherwise lack access to these devices could benefit from their reuse.

Do gender differences exist in pacemaker implantation?--results of an obligatory external quality control program

AIMS

The aim of the study was to evaluate the effects of patient gender onto primary pacemaker implantation, evaluating the database of the Institute of Quality Assurance Hessen in the federal state of Hessen, Germany.

METHODS AND RESULTS

The database of the obligatory external quality control program for the years 2003-2006 was evaluated retrospectively. In 72 centres, 17 826 patients undergoing stationary primary pacemaker implantation have been registered. Male patients had more AV blocks when compared with women and less sick sinus syndrome and atrial fibrillation with bradycardia. In patients being 80 years and older, men received significantly more dual-chamber devices than women for the indications: AV block and sick sinus syndrome. In women, atrial pacing thresholds were significantly higher and P-wave amplitudes were significantly lower. Women had, independent from age or pacing system implanted, significantly more acute complications than men, with significant differences for pneumothorax and pocket haematoma.

CONCLUSION

This large-scale real-life patient cohort of primary stationary pacemaker implantation showed that gender has an impact onto pacemaker implantation, with less favourable outcomes for women.

Effect of electroporation on cardiac electrophysiology

Defibrillation shocks are commonly used to terminate life-threatening arrhythmias. According to the excitation theory of defibrillation, such shocks are aimed at depolarizing the membranes of most cardiac cells, resulting in resynchronization of electrical activity in the heart. If shock-induced transmembrane potentials are large enough, they can cause transient tissue damage due to electroporation. In this review, evidence is presented that electroporation of the heart tissue can occur during clinically relevant intensities of the external electrical field and that electroporation can affect the outcome of defibrillation therapy, being both pro- and antiarrhythmic.Here, we present experimental evidence for electroporation in cardiac tissue, which occurs above a threshold of 25 V/cm as evident from propidium iodide uptake, transient diastolic depolarization, and reductions of action potential amplitude and its derivative. These electrophysiological changes can induce tachyarrhythmia, due to conduction block and possibly triggered activity; however, our findings provide the foundation for future design of effective methods to deliver genes and drugs to cardiac tissues, while avoiding possible side effects such as arrhythmia and mechanical stunning.

Supraventricular Dysrhythmias

Cardiovascular nursing practice includes accountability for the clinical and organizational processes to ensure positive outcomes for patients having cardiac dysrhythmias. For patients with supraventricular dysrhythmias, nurses have studied patient outcomes related to mortality, morbidity, quality of life, psychological and physical functioning, and symptoms. Nurses have also explored these same outcomes associated with the management of supraventricular dysrhythmias. In addition, nurses have contributed to understanding organizational outcomes such as healthcare utilization and costs associated with these patients. For patients with atrial fibrillation after cardiac surgery, nurses have studied patient and organizational outcomes related to mortality, morbidity, symptoms, psychological and physical functioning, and economic outcomes. This research has included numerous interdisciplinary studies, and most of it has been descriptive or observational in design. Areas for future nursing outcomes research, including more interventional studies, are discussed.

N-terminal brain natriuretic peptide as a screening tool for heart failure in the pacemaker population

AIMS

Assessment of N-terminal brain natriuretic peptide (NT-BNP) as a screening tool for heart failure in patients with a permanent pacemaker.

METHODS AND RESULTS

Consecutive patients undergoing a routine permanent pacemaker assessment were enrolled. Patients underwent medical history and examination, echocardiography and blood sampling for NT-BNP. Analysis was performed on 261 patients (132 DDD, 121 VVI, eight others), mean age 73+/-12 years, range 34-99 years. Seventy two subjects (27%) had heart failure as defined by left ventricular ejection fraction (LVEF) <or=40% and symptoms of heart failure (NYHA class II, III, or IV). Screening with NT-BNP gave a sensitivity of 73% and specificity of 72% for detecting heart failure in all patients [area under the curve (AUC) 0.76, P<0.001, 95% CI 0.69-0.83]. This increased in subjects with a DDD type pacemaker (sensitivity 80%, specificity 66%, AUC=0.8, CI 0.7-0.90) and reduced in subjects with a VVI type pacemaker (sensitivity 66%, specificity 61%, AUC 0.68 CI 0.57-0.78).

CONCLUSION

Symptoms of heart failure are common in patients with pacemakers. Screening with NT-BNP is feasible and assists in the detection of important cardiac co-morbidity, particularly in patients with a DDD type pacemaker.

Ageing-related changes of connexins and conduction within the sinoatrial node

Clinical studies have shown that sinoatrial node dysfunction occurs at the highest incidence in the elderly population. Guinea-pigs were studied throughout their lifespan (i.e. birth to 38 months) to investigate the possible mechanism leading to nodal dysfunction. Using immunofluorescence with confocal microscopy, Cx43 protein expression was shown at birth to be present throughout the sinoatrial node and atrial muscle, however, at one month Cx43 protein was not expressed in the centre of the sinoatrial node. Throughout the remainder of the animal's lifespan the area of tissue lacking Cx43 protein progressively increased. Western blot provided verification by quantitative analysis that Cx43 protein expression within the sinoatrial node decreased with age; however, the expression of other cardiac connexins, Cx40 and Cx45, did not differ with age. Analysis of conduction maps showing propagation of the action potential across the sinoatrial node, from the initiation point to the crista terminalis, found that the action potential conduction time taken and conduction distance increased proportionally with age; conversely the conduction velocity decreased with age. We have shown ageing induces degenerative changes in action potential conduction, contributed to by the observed loss of Cx43 protein. Our data identify Cx43 as a potential therapeutic target for quashing the age-related deterioration of the cardiac pacemaker.