Pacemaker Implantation as a Risk Factor for Heart Failure in Young Adults with Congenital Heart Disease

Trends in cardiac implantable electronic device utilization in adults with congenital heart disease: a US nationwide analysis

BACKGROUND

Adults with congenital heart disease (ACHD) have increased risk of arrhythmias warranting implantation of cardiac implantable electronic devices (CIEDs), which may parallel the observed increase in survival of ACHD patients over the past few decades. We sought to characterize the trends and outcomes of CIED implantation in the inpatient ACHD population across US from 2005 to 2019.

METHODS

A retrospective analysis of the Nationwide Inpatient Sample (NIS) identified 1,599,519 unique inpatient ACHD admissions (stratified as simple (85.1%), moderate (11.5%), and complex (3.4%)) using the International Classification of Diseases 9/10-CM codes. Hospitalizations for CIED implantation (pacemaker, ICD, CRT-p/CRT-d) were identified and the trends analyzed using regression analysis (2-tailed p < 0.05 was considered significant).

RESULTS

A significant decrease in the hospitalizations for CIED implantation across the study period [3.3 (2.9-3.8)% in 2005 vs 2.4 (2.1-2.6)% in 2019, p < 0.001] was observed across all types of devices and CHD severities. Pacemaker implantation increased with each age decade, whereas ICD implantation rates decreased over 70 years of age. Complex ACHD patients receiving CIED were younger with a lower prevalence of age-related comorbidities, however, had a greater prevalence of atrial/ventricular tachyarrhythmias and complete heart block. The observed inpatient mortality rate was 1.2%.

CONCLUSIONS

In a nationwide analysis, we report a significant decline in CIED implantation between 2005 and 2019 in ACHD patients. This may either be due to a greater proportion of hospitalizations resulting from other complications of ACHD or reflect a declining need for CIED due to advances in medical/surgical therapies. Future prospective studies are needed to elucidate this trend further.

Long-Term Risk of Heart Failure-Related Death and Heart Transplant After Congenital Heart Surgery in Childhood (from the Pediatric Cardiac Care Consortium)

We aimed to describe the longitudinal risk of advanced heart failure (HF) leading to death, heart transplantation, or ventricular assist device (VAD) placement after congenital heart surgery (CHS) and how it varies across the spectrum of congenital heart disease. We linked the records of patients who underwent first CHS in the Pediatric Cardiac Care Consortium between 1982 and 2003 with the United States National Death Index and Organ Procurement and Transplantation Network databases. Primary outcome was time from CHS discharge to HF-related death, heart transplant, or VAD placement, analyzed with proportional hazards models accounting for competing mortality. In 35,610 patients who survived a first CHS, there were 799 HF deaths, transplants, or VADs over a median of 23 years (interquartile range, 19 to 27). Cumulative incidence at 25 years was 2.3% (95% confidence interval [CI] 2.1% to 2.4%). Compared to mild 2-ventricle defects, the adjusted subhazard ratio for moderate and severe 2-ventricle defects was 3.21 (95% CI 2.28 to 4.52) and 9.46 (95% CI 6.71 to 13.3), respectively, and for single-ventricle defects 31.8 (95% CI 22.2 to 45.6). Systemic right ventricle carried the highest risk 2 years after CHS (subhazard ratio 2.76 [95% CI 2.08 to 3.68]). All groups had higher rates of HF-related death compared with the general population (cause-specific standardized mortality ratio 56.1 [95% CI 51.0 to 61.2]). In conclusion, the risk of advanced HF leading to death, transplantation, or VAD was high across the spectrum of congenital heart disease. While severe defects carry the highest risk, those with mild disease are still at greater risk than the general population.

Implantable cardiac electronic device therapy for patients with a systemic right ventricle

The systemic right ventricle (SRV), defined as the morphological right ventricle supporting the systemic circulation, is relatively common in congenital heart disease (CHD). Our review aimed at examining the current evidence, knowledge gaps and technical considerations regarding implantable cardiac electronic device therapy in patients with SRV. The risk of sinus node dysfunction (SND) after atrial switch repair and/or complete heart block in congenitally corrected transposition of great arteries requiring permanent pacing increases with age. Similar to acquired heart disease, indication for pacing includes symptomatic bradycardia, SND and high degree atrioventricular nodal block. Right ventricular dysfunction and heart failure also represent important complications in SRV patients. Cardiac resynchronisation therapy (CRT) has been proposed to improve systolic function in SRV patients, although indications for CRT are not well defined and its potential benefit remains uncertain. Amongst adult CHD, patients with SRV are at the highest risk for sudden cardiac death (SCD). Nevertheless, risk stratification for SCD is scarce in this cohort and implantable cardioverter-defibrillator indication is currently limited to secondary prevention. Vascular access and the incidence of device-related complications, such as infections, inappropriate shocks and device system failure, represent additional challenges to implantable cardiac electronic device therapy in patients with SRV. A multidisciplinary approach with tertiary expertise and future collaborative research are all paramount to further the care for this challenging nonetheless ever increasing cohort of patients.

Functional capacity of patients with pacemaker due to isolated congenital atrioventricular block

BACKGROUND

Isolated congenital atrioventricular block (CAVB) is a rare condition with multiple clinical outcomes. Ventricular remodeling can occur in approximately 10% of the patients after pacemaker (PM) implantation.

OBJECTIVES

To assess the functional capacity of children and young adults with isolated CAVB and chronic pacing of the right ventricle (RV) and evaluate its correlation with predictors of ventricular remodeling.

METHODS

This cross-sectional study used a cohort of patients with isolated CAVB and RV pacing for over a year. The subjects underwent clinical and echocardiographic evaluation. Functional capacity was assessed using the six-minute walk test. Chi-square test, Fisher's exact test, and Pearson correlation coefficient were used, considering a significance level of 5%.

RESULTS

A total of 61 individuals were evaluated between March 2010 and December 2013, of which 67.2% were women, aged between 7 and 41 years, who were using PMs for 13.5 ± 6.3 years. The percentage of ventricular pacing was 97.9 ± 4.1%, and the duration of the paced QRS complex was 153.7 ± 19.1 ms. Majority of the subjects (95.1%) were asymptomatic and did not use any medication. The mean distance walked was 546.9 ± 76.2 meters and was strongly correlated with the predicted distance (r = 0.907, p = 0.001) but not with risk factors for ventricular remodeling. (Arq Bras Cardiol. 2014; [online].ahead print, PP.0-0) CONCLUSIONS: The functional capacity of isolated CAVB patients with chronic RV pacing was satisfactory but did not correlate with risk factors for ventricular remodeling.

Tissue doppler changes in pediatric complete heart block patients who are chronically paced

INTRODUCTION

Pediatric patients with complete heart block (CHB) often require pacemaker therapy. Adult studies have shown chronic right ventricular pacemaker therapy may be associated with decreased echocardiographic parameters and increased brain natriuretic peptide (BNP) values. The goal of this study was to determine if there are echocardiographic or BNP changes in a pediatric population that is chronically paced.

METHODS

Patients were recruited if they had CHB and had a pacemaker. Patients were excluded if they had congenital structural heart disease. Standard two-dimensional echocardiograms, including tissue Doppler imaging (TDI), were performed. BNP values were obtained. Nonparametric Spearman's rank correlation was used for analysis. Rho < or = 0.05 was considered significant.

RESULTS

Eighteen patients (16.4 +/- 7.3 years) with CHB were studied. Age at implant was 8.6 +/- 6.6 years and length of pacing was 7.8 +/- 6.6 years. Pacing mode was VDD, DDD, DDDR, or VVIR. All patients were ventricularly paced >95% of the time. Ejection fraction was 58.5 +/- 7.5%. All BNP values were <40 pg/mL. There was no correlation between ejection fraction or BNP level with the length of pacing years. Pacing years significantly correlated with mitral and tricuspid E/A ratios (rho =-0.56, -0.56, respectively). Pacing years also correlated with right ventricular and interventricular TDI a wave (rho = 0.61 and 0.68, respectively). Furthermore, pacing years correlated with right ventricular TDI e/a ratio (rho =-0.58).

CONCLUSIONS

Ejection fraction and BNP levels were not sensitive parameters in evaluating pediatric patients who are chronically paced. Subtle diastolic changes, especially of the right ventricle, were detected by TDI.

Impact of right ventricular pacing on three-dimensional global left ventricular dyssynchrony in children and young adults with congenital and acquired heart block associated with congenital heart disease

The aim of this study was to determine the effect of long-term right ventricular pacing on left ventricular (LV) mechanical dyssynchrony in children and young adults with congenital and acquired heart block. Eighteen patients aged 19 +/- 7 years with congenital heart block (group I), 9 aged 21 +/- 11 years with acquired heart block after congenital heart surgery (group II), and 15 healthy control subjects (group III) were studied. The LV volumes, ejection fractions, and systolic dyssynchrony index (SDI) values, as determined using 3-dimensional echocardiography, were compared among groups. Groups I (6.68 +/- 2.44%) and II (9.43 +/- 4.44%) had significantly greater SDI values than group III (3.88 +/- 0.63%) (p = 0.011 and p <0.001, respectively). The prevalence of LV mechanical dyssynchrony (SDI >5.14%, mean + 2 SDs of controls) in groups I and II was 72% and 67%, respectively. In 27 patients with right ventricular pacing, LV SDI values were correlated negatively with the LV ejection fractions (r = -0.74, p <0.001). The times to minimum regional volume were significantly longer in lateral, posterior, and inferior segments in group I and septal and inferior segments in group II compared to those in group III (p <0.05). Compared to patients without LV dyssynchrony, patients with LV dyssynchrony had lower LV ejection fractions (p <0.001), had shorter RR intervals (p <0.001), and tended to have dual-chamber pacing (p = 0.088) but had similar durations of pacing, QRS durations, and positions of pacing wires (epicardial vs endocardial). In conclusion, permanent right ventricular pacing in childhood has a negative effect on LV systolic function through the induction of mechanical dyssynchrony, the magnitude and pattern of which differ between congenital and acquired heart block.

Managed ventricular pacing in pediatric patients and patients with congenital heart disease

Ventricular dyssynchrony induced by ventricular pacing (VP) may predispose patients to congestive heart failure. The detrimental effects of VP are directly related to the cumulative percentage of VP (Cum%VP). Managed VP (MVP) is a novel pacing algorithm developed to minimize unnecessary VP by uncoupling atrial pacing from VP. This retrospective analysis assessed the feasibility of using MVP in pediatric patients and patients with congenital heart disease (CHD). A multicenter review evaluated all pediatric patients <22 years old and older patients with CHD that had an implanted device using a MVP algorithm. Primary outcome variables were Cum%VP and adverse events. A subgroup analysis evaluated patients that had a DDD(R) pacemaker before a MVP device and compared Cum%VP before and after initiation of MVP. From 6 centers 62 patients (mean age 21.5 +/- 9.6 years) were included; 64% had CHD. With a MVP device, mean Cum%VP was 4.3 +/- 14.6% (range 0 to 83.7): Eleven patients were eligible for subgroup analysis. Compared with DDD(R), Cum%VP significantly decreased with MVP (67.1 +/- 29.4% vs 9.2 +/- 24.8%, p = 0.002). One MVP-related adverse event occurred; a patient with intermittent atrioventricular block had symptoms with frequent nonconducted atrial depolarizations and was reprogrammed to DDD. In conclusion, MVP can be used safely and can significantly reduce unnecessary VP in pediatric patients and patients with CHD.

Successful cardiac resynchronization with single-site left ventricular pacing in children

BACKGROUND

Dyssynchronous left ventricular (LV) contraction due to permanent right ventricular apex (RVA) pacing or delayed electrical activation as typically observed in left bundle brunch block (LBBB) has a negative impact on LV function. Objective was to evaluate the impact of epicardial single-site LV pacing in children on LV function and resynchronization.

PATIENTS

Single-site epicardial LV free wall pacing was established in 6 children with congenital heart disease and echocardiographic signs of LV dyssynchrony. Reasons for dyssynchrony were either long-term RVA pacing (n=5; pacing duration: 7.7+/-2.4 years) or LBBB with drug-resistant congestive heart failure (n=1).

RESULTS

After 1 month of single-site LV pacing, LV ejection fraction increased (41+/-6 versus 53+/-8%) and LV enddiastolic volume decreased (70+/-22 versus 63+/-18 ml/m(2)) as compared to pre-implant measurements. Interventricular mechanical delay decreased (67+/-15 versus 16+/-15 ms) and intraventricular synchrony was restored (septal-to-posterior wall motion delay: 312+/-24 versus 95+/-57 ms). Accordingly, circumferential 2D strain demonstrated a decrease of LV mechanical delay (201+/-35 versus 99+/-23 ms).

CONCLUSION

After 1 month of single-site LV pacing, conventional and 2D strain derived echocardiographic measurements indicated improved ventricular function and synchronization in children with previous RVA pacing or LBBB. Further studies are needed to evaluate whether single-site LV pacing may be sufficient for resynchronization therapy.

Evaluation of left ventricular diastolic functions in patients with frequent premature ventricular contractions from right ventricular outflow tract

This study was sought to examine the effects of repetitive monomorphic premature ventricular contractions (PVCs) on left ventricular (LV) diastolic function. Thirty-three symptomatic patients (Study group, 10 males, mean age 40 +/- 8 years) with normal LV systolic function and repetitive PVCs originating from the right ventricular outflow tract (RVOT-PVCs) on 24-h Holter monitoring, and 30 healthy controls (Control group, 9 males, mean age 37 +/- 9 years) were enrolled in the study. None of the patients had structural heart disease. Diastolic function was assessed by echocardiographic mitral inflow pattern and tissue Doppler imaging. The study group displayed a lower E/A ratio, longer isovolumetric relaxation time (IVRT), and longer E-wave deceleration time (EDT). In the study group 13 patients showed impaired relaxation. While mean values of the systolic velocity (Sa), early diastolic velocity (Ea), and early/late diastolic velocity (Ea/Aa) ratio were significantly lower in the study group, the Aa velocity and E/Ea ratio were significantly higher. Ea velocity was <10 cm/s in 7 study patients. Mitral inflow pattern and Ea velocity was normal in all controls. Significant correlations were found between ventricular premature beats percentage and early to late transmitral flow velocity ratio, EDT, IVRT, Ea velocity, the Ea/Aa ratio, and the E/Ea ratio. In multivariate analysis, total PVC count and age were found to be independent predictors of impaired relaxation. These results suggest that repetitive monomorphic RVOT-PVCs lead to abnormalities of LV diastolic function that may contribute to clinical symptoms in patients with structurally normal hearts.

Chronotropic Incompetence in Adolescents and Adults With Congenital Heart Disease After Cardiac Surgery

BACKGROUND

Chronotropic incompetence (CI) is one of the major problems in adults with congestive heart. Little is known about CI in adults with congenital heart disease (ACHD) after cardiac surgery. The purpose of our study was to investigate the presence and risk factors of CI in ACHD patients.

METHODS AND RESULTS

Clinical and echocardiographic data, NT-pro brain natriuretic peptide (N-BNP), and peak oxygen uptake (VO2peak) during spiroergometry were obtained in 345 consecutive ACHD patients. CI was defined as the failure to achieve > or = 80% of the predicted maximal heart rate. A total of 117 (34%) of study patients fulfilled the CI criterion. These patients were in a higher New York Heart Association class (1.7 +/- 0.06 versus 1.4 +/- 0.03, P < .0001; mean +/- SEM), had significantly higher N-BNP levels (230 +/- 31 versus 121 +/- 10 pg/mL, P < .0001) and a more pronounced impairment of VO2peak (23.8 +/- 0.6 versus 28.4 +/- 0.5 mL x kg x min, P < .0001) than those without CI. Elevated odds ratios for CI were found in patients with a single ventricle (4.03), Mustard operation for transposition of the great arteries (3.11), and aortic coarctation (2.14).

CONCLUSIONS

Our results indicate that CI in ACHD patients is a frequent problem and is related to the severity of the heart failure as measured by symptom assessment (New York Heart Association class), plasma N-BNP level and peak oxygen uptake.