Abstract
Background
Increasing use of cardiac implantable electronic devices (CIEDs) has raised concerns about psychological distress in young adults. We evaluated the risk of incident mental disorders after CIED implantation.
Methods
Using the Korean National Health Insurance database, we identified individuals aged 20 to 39 years who underwent health checkups in 2009 to 2012. Those receiving a new CIED within 4 years were included, and controls were selected by 1:5 matching for age, sex, and index year. The primary outcome was a composite of newly diagnosed mental disorders (mood disorders and anxiety/stress‐related/somatoform disorders), and secondary outcomes were the individual components.
Results
There were 569 CIED recipients (209 pacemakers, 360 implantable cardioverter‐defibrillators) and 2821 matched controls analyzed. Over a median follow‐up of 5.3 years, both the pacemaker and implantable cardioverter‐defibrillator implantations were associated with a significantly higher risk of the primary outcome compared with no device (hazard ratio [HR], 1.63 [95% CI, 1.20–2.21] and HR, 1.80 [95% CI, 1.39–2.35], respectively). In head‐to‐head analyses, the risk of the primary outcome did not differ significantly between implantable cardioverter‐defibrillator and pacemaker recipients (adjusted HR, 1.09 [95% CI, 0.75–1.59]). Risks of secondary outcomes were also increased in both device groups. CIED recipients had a 1.95‐fold higher risk of mental disorders within 2 years postimplantation (95% CI, 1.45–2.62), and this elevated risk persisted beyond 2 years (HR, 1.54 [95% CI, 1.13–2.11]).
Conclusions
Among young individuals, both pacemaker and implantable cardioverter‐defibrillator implantations were associated with increased risks of mental disorders, supporting proactive psychological screening and interventions.
Keywords: anxiety disorders, cardiology, mental health, mood disorders
Subject Categories: Mental Health
Short abstract
Nonstandard Abbreviations and Acronyms
- NHIS
National Health Insurance Service
Clinical Perspective.
What Is New?
• In this nationwide population‐based study, both pacemaker and implantable cardioverter‐defibrillator implantations were significantly associated with an increased risk of mental disorders in young adults. Notably, this elevated risk persisted beyond 2 years after implantation.
What Are the Clinical Implications?
• These findings highlight the importance of early screening and mental health management in young patients with cardiac implantable electronic devices, suggesting that long‐term psychological support may also be beneficial.
Cardiac implantable electronic devices (CIEDs), including pacemakers, implantable cardioverter‐defibrillators (ICDs), and cardiac resynchronization therapy systems, are a cornerstone in the management of various arrhythmias and prevention of sudden cardiac death. 1 Owing to their significant clinical benefits, the global implantation rates of CIEDs have steadily increased over recent decades. 2 , 3 , 4
As the number of individuals receiving CIEDs continues to rise, increasing attention has been directed toward potential complications following device implantation. 5 Physical complications, including infections, lead perforation, and lead dislodgement, are well known; however, psychological distress is another necessary and often underappreciated consequence of CIED therapy. 6 The implantation procedure per se can provoke acute mental stress. 7 Moreover, after hospital discharge, CIED recipients may suffer from chronic anxiety related to shocks, potential malfunction, or long‐term dependence on the device. 8 These concerns are particularly pronounced among young individuals, who will likely live with their devices for many decades. Younger patients may face issues such as physical activity limitations, altered body image, and persistent worry about device failure. 6 , 9 Furthermore, mental disorders in young people have been associated with an increased risk of cardiovascular diseases, 10 indicating that psychological well‐being is crucial not only for quality of life but also for long‐term cardiac outcomes. Given the bidirectional relationship between mental and cardiovascular health, 11 , 12 it is crucial to understand the impact of CIED implantation on mental disorders in this population.
Therefore, we conducted a nationwide Korean cohort study to determine the risk of new‐onset mental disorders after pacemaker or ICD implantation in young adults.
METHODS
Data, Methods, and Materials Availability
The data that support the findings of this study are available from the Korean National Health Insurance Service (NHIS), but restrictions apply to the availability of these data. Data access can be obtained through the NHIS data sharing service upon reasonable request and with permission of the NHIS. The analytic methods are described in this article and in the Supplemental Material. Analytic code can be made available from the corresponding author upon reasonable request.
Data Source and Study Population
This study used the Korean NHIS database, which provides comprehensive health information for the entire Korean population under the mandatory universal health coverage system. The NHIS database includes demographic characteristics, diagnostic codes, prescription records, procedural details, and results of biennial general health checkups. 13 Diagnostic codes in the database are based on the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD‐10‐CM).
We identified individuals aged 20 to 39 years who underwent a general health checkup between 2009 and 2012. Patients with a history of CIED implantation before the health checkup were excluded. From the remaining cohort, we included individuals who underwent first‐time CIED implantation within 4 years of their health checkup; the date of device implantation was defined as the index date. We further excluded individuals with a documented history of mental disorders before the index date, as well as those who received a CIED >4 years after their health checkup. The final CIED group was further categorized into 2 subsets according to the type of device implanted (pacemaker or ICD). For each CIED recipient, up to 5 controls without prior CIED implantation were randomly selected and exactly matched on age, sex, and index year. Controls were assigned the same index date as their matched CIED recipient and were required to be event‐free on that date. The same exclusion criteria were applied to the potential controls. All participants were followed up from their index date until the occurrence of the outcome or the end of 2020, whichever came first.
The study protocol conformed to the ethical guidelines of the Declaration of Helsinki and was approved by the institutional review board of our institution (institutional review board number E‐2505‐087‐1639). The requirement for informed consent was waived because anonymized information from the NHIS database was retrospectively collected and assessed.
Identification of Mental Disorders
Mental disorders were identified by using diagnostic codes from the NHIS database. We focused on 2 categories of disorders: (1) mood disorders, including affective disorders with or without psychotic features; and (2) anxiety, stress‐related, and somatoform disorders. We defined an incident mental disorder as the presence of relevant ICD‐10‐CM diagnostic codes on at least 2 separate medical encounters within 12 months during follow‐up. 11 , 14 , 15 We did not use psychiatric medication claims to define outcomes, because these medications have broad indications, including off‐label use, which may increase misclassification. 16 The primary outcome was the composite of any mood disorder and any anxiety/stress‐related/somatoform disorder diagnosed after the index date. The secondary outcomes were the individual components of this composite, evaluated as the occurrence of any mood disorder and of any anxiety/stress‐related/somatoform disorder, respectively. The specific ICD‐10‐CM codes used to define the outcomes are listed in Table S1.
Covariates
The baseline characteristics and potential confounding variables were obtained from the database. Conditions of interest, including hypertension, diabetes, dyslipidemia, myocardial infarction, heart failure, atrial fibrillation, cardiomyopathy, and congenital heart disease were identified using ICD‐10‐CM codes and defined according to established criteria. 17 , 18 Socioeconomic status was approximated by income level, with low income defined as being in the lowest quartile of annual income or receiving medical aid. Lifestyle factors, such as smoking status, alcohol consumption, and regular physical activity, were collected from health checkup questionnaires. Detailed definitions of all covariates are summarized in Table S2.
Statistical Analysis
Continuous variables are expressed as mean±SD or median with interquartile range, and categorical variables are presented as numbers and percentages. Baseline characteristics were compared between the groups using the unpaired Student t test for continuous variables and the χ2 test or Fisher exact test for categorical variables, as appropriate. The incidence of mental disorders was calculated per 1000 person‐years of follow‐up. Kaplan‐Meier curves were generated to illustrate the cumulative incidence of primary and secondary outcomes according to CIED implantation, and differences between groups were assessed using the log‐rank test. To evaluate the association between CIED implantation and the risk of mental disorders, we used Cox proportional hazard regression to compute hazard ratios (HRs) and 95% CIs. The proportional hazards assumption was verified based on Schoenfeld residuals and their plots. In the multivariable Cox models, we adjusted for age, sex, hypertension, diabetes, dyslipidemia, myocardial infarction, heart failure, atrial fibrillation, low‐income status, smoking, alcohol intake, and regular physical activity at baseline. In addition, we further adjusted for cardiomyopathy and congenital heart disease, which are major conditions leading to CIED implantations in young adults, to minimize confounding by underlying diseases.
To compare mental disorder risk by device type, we conducted a head‐to‐head analysis between ICD and pacemaker recipients. Using pacemaker recipients as the reference group, we estimated adjusted HRs for ICD recipients with Cox proportional hazards models and compared the 2 groups using Kaplan‐Meier curves with log‐rank tests.
To more thoroughly address baseline differences between CIED recipients and nonrecipients, propensity score matching was applied as a sensitivity analysis. Propensity scores were estimated using logistic regression including baseline demographic, socioeconomic, comorbidity, and lifestyle variables measured at the health checkup. We then performed 1:1 optimal matching without replacement using a caliper of 0.2. Postmatching balance was examined using standardized mean difference, with a value ≤0.1 considered acceptable. Outcomes were compared in the matched cohort using Kaplan‐Meier curves with log‐rank tests and Cox proportional hazards models. Covariates that remained imbalanced after matching were additionally adjusted for in the postmatching Cox models.
As an additional sensitivity analysis addressing the recurrent nature of mental disorders, we conducted recurrent‐event analyses using an Andersen‐Gill model, allowing multiple mental disorder‐related claim events per individual. Robust sandwich‐type variance estimators were used to account for within‐individual correlation. Because claims data do not capture episode boundaries, these recurrent‐event estimates were interpreted as the burden of repeated mental health‐related health care encounters.
To assess how the relative risk may change over time, we conducted time‐stratified analyses, splitting the follow‐up duration into 2 periods: ≤2 years and >2 years after the index date. Subgroup analyses were also performed to determine whether the effects of CIED on mental disorders were modified by various factors. Subgroups were stratified according to age, sex, body mass index (BMI), smoking, drinking, regular exercise, and low income. Effect modification was assessed by including multiplicative interaction terms between CIED implantation and each subgroup variable in the fully adjusted model; P values for interaction were obtained using Wald tests. All statistical tests were 2‐tailed, and a P value <0.05 was considered statistically significant. Analyses were performed using SAS version 9.4 (SAS Institute, Cary, NC).
RESULTS
Baseline Characteristics
The study cohort comprised 569 individuals in the CIED group and 2821 matched individuals in the control group. Among the patients in the CIED group, 209 and 360 received a pacemaker and an ICD, respectively (Figure 1). None of the patients who received cardiac resynchronization therapy devices met the inclusion criteria. The baseline characteristics of the study population according to the device type are summarized in Table 1. The mean age of the total cohort was 36.7±6.0 years, and 81.5% were men. The pacemaker subgroup had a lower proportion of men (70.8%) than did the ICD implantation subgroup (89.7%). Major comorbidities, including hypertension, dyslipidemia, heart failure, and atrial fibrillation, were significantly more prevalent in both pacemaker and ICD recipients than in the control group. Additional baseline characteristics, stratified according to the presence or absence of CIED implantation, are presented in Table S3.
Figure 1. Study design.
Schematic representation illustrating the selection of the study population. CIED indicates cardiac implantable electronic device; and ICD, implantable cardioverter‐defibrillator.
Table 1.
Baseline Clinical Characteristics According to Device Type
| No CIED (n=2821) | Pacemaker (n=209) | ICD (n=360) | P value | |
|---|---|---|---|---|
| Demographics | ||||
| Age, y | 36.6±6.0 | 36.5±6.5 | 36.9±5.8 | 0.705 |
| Men | 2290 (81.2) | 148 (70.8) | 323 (89.7) | <0.001 |
| BMI, kg/m2 | 24.3±3.6 | 23.6±3.6 | 25.0±3.8 | <0.001 |
| Comorbidities | ||||
| Hypertension | 377 (13.4) | 58 (27.8) | 140 (38.9) | <0.001 |
| Diabetes | 143 (5.1) | 11 (5.3) | 25 (7.0) | 0.326 |
| Dyslipidemia | 410 (14.5) | 43 (20.6) | 97 (26.9) | <0.001 |
| Myocardial infarction | 1 (0.04) | 2 (1.0) | 23 (6.4) | <0.001 |
| Heart failure | 14 (0.5) | 23 (11.0) | 106 (29.4) | <0.001 |
| Atrial fibrillation | 2 (0.1) | 30 (14.4) | 54 (15.0) | <0.001 |
| Cardiomyopathy | 1 (0.04) | 4 (1.91) | 97 (26.9) | <0.001 |
| Congenital heart disease | 1 (0.04) | 32 (15.3) | 9 (2.5) | <0.001 |
| Physical examination | ||||
| SBP, mm Hg | 121.4±13.5 | 120.3±13.9 | 122.2±14.9 | 0.283 |
| DBP, mm Hg | 76.5±10.0 | 74.2±10.5 | 76.8±10.6 | 0.005 |
| Lifestyle behaviors | ||||
| Tobacco smoking | <0.001 | |||
| Never smoker | 1141 (40.5) | 106 (50.7) | 116 (32.2) | |
| Former smoker | 513 (18.2) | 38 (18.2) | 93 (25.8) | |
| Current smoker | 1167 (41.4) | 65 (31.1) | 151 (41.9) | |
| Alcohol consumption | 0.021 | |||
| Nondrinker | 799 (28.3) | 82 (39.2) | 109 (30.3) | |
| Mild to moderate drinker | 1705 (60.4) | 107 (51.2) | 216 (60.0) | |
| Heavy drinker | 317 (11.2) | 20 (9.6) | 35 (9.7) | |
| Regular physical activity | 507 (18.0) | 38 (18.2) | 77 (21.4) | 0.361 |
| Low income | 259 (9.2) | 61 (29.2) | 37 (10.3) | <0.001 |
| Laboratory data | ||||
| Total cholesterol, mg/dL | 195.3±35.8 | 187.0±36.8 | 195.7±39.1 | 0.006 |
| LDL cholesterol, mg/dL | 110.5±35.5 | 106.0±32.8 | 112.4±33.5 | 0.158 |
| HDL cholesterol, mg/dL | 54.6±18.8 | 56.2±15.3 | 53.0±12.8 | 0.119 |
| Fasting blood glucose, mg/dL | 96.7±21.5 | 93.9±18.4 | 97.3±23.7 | 0.162 |
| GFR, mL/min per 1.73 m2 | 97.0±44.3 | 96.7±25.6 | 93.1±21.2 | 0.244 |
Values are mean±SD or n (percent). BMI indicates body mass index; CIED, cardiac implantable electronic device; DBP, diastolic blood pressure; GFR, glomerular filtration rate; HDL, high‐density lipoprotein; ICD, implantable cardioverter‐defibrillator; LDL, low‐density lipoprotein; and SBP, systolic blood pressure.
Incidence of Mental Disorders and Association With CIED Implantation
Over a median follow‐up of 5.3 years (interquartile range, 3.1–8.4), 643 individuals in the entire cohort developed new‐onset mental disorders. This included 490 and 153 events in 2821 controls (incidence rate, 29.7 per 1000 person‐years) and in 569 CIED recipients (incidence rate, 52.1 per 1000 person‐years), respectively. When stratified by device type, there were 56 and 97 incident cases among the 209 pacemaker recipients (incidence rate, 49.0 per 1000 person‐years) and 360 ICD recipients (incidence rate, 54.1 per 1000 person‐years), respectively. Kaplan‐Meier analysis demonstrated a significantly higher cumulative incidence of newly diagnosed mental disorders in individuals with CIEDs than it did in those without CIEDs (log‐rank P<0.001; Figure S1). A similar pattern was observed for each category of disorders examined separately. The relative risks of mental disorders associated with CIED implantation are shown in Table S4.
Figure 2 shows the Kaplan‐Meier curves stratified into 3 groups: pacemaker recipients, ICD recipients, and control subjects. Both pacemaker and ICD recipients had a markedly higher risk of the composite outcome of mental disorders than did the non‐CIED controls (log‐rank P < 0.001 for the overall comparison). Moreover, the cumulative incidence of mood and anxiety/stress‐related/somatoform disorders was significantly greater in the pacemaker and ICD groups than in the control group (log‐rank P < 0.001 for both). In multivariable Cox proportional hazards models (Table 2), CIED implantation remained an independent predictor of incident mental disorders with pacemaker (HR, 1.63 [95% CI, 1.20–2.21]) and ICD (HR, 1.80 [95% CI, 1.39–2.35]) recipients, with both demonstrating a significantly elevated risk compared with controls. Additionally, the risks of secondary outcomes significantly increased in both pacemaker and ICD recipients. For new‐onset mood disorders, the adjusted HRs were 1.85 (95% CI, 1.17–2.93) and 2.49 (95% CI, 1.70–3.63) for pacemaker and ICD recipients, respectively, compared with controls. Similarly, for anxiety/stress‐related/somatoform disorders, pacemaker (HR, 1.49 [95% CI, 1.06–2.09]) and ICD (HR, 1.78 [95% CI, 1.34–2.37]) recipients exhibited higher risks than control subjects.
Figure 2. Kaplan‐Meier survival curves for mental disorders.
Kaplan‐Meier curves demonstrating the cumulative incidence of mental disorders among individuals stratified into PM recipients, ICD recipients, and controls without CIEDs. CIED indicates cardiac implantable electronic device; ICD, implantable cardioverter‐defibrillator; and PM, pacemaker.
Table 2.
Risk of Mental Disorders After Pacemaker and ICD Implantation
| Outcome | Group | Events, n | Person‐years | IR | Model 1*, HR (95% CI) | Model 2†, HR (95% CI) |
|---|---|---|---|---|---|---|
| A composite of mood, anxiety, stress‐related, and somatoform disorders | No CIED | 490 | 16472.2 | 29.7 | Reference | Reference |
| Pacemaker | 56 | 1142.9 | 49.0 | 1.64 (1.24–2.16) | 1.63 (1.20–2.21) | |
| ICD | 97 | 1791.4 | 54.1 | 1.81 (1.46–2.25) | 1.80 (1.39–2.35) | |
| Mood disorders | No CIED | 175 | 17893.8 | 9.8 | Reference | Reference |
| Pacemaker | 27 | 1315.5 | 20.5 | 2.08 (1.39–3.12) | 1.85 (1.17–2.93) | |
| ICD | 48 | 2032.7 | 23.6 | 2.42 (1.76–3.33) | 2.49 (1.70–3.63) | |
| Anxiety/stress‐related/somatoform disorders | No CIED | 422 | 16785.1 | 25.1 | Reference | Reference |
| Pacemaker | 45 | 1206.5 | 37.3 | 1.48 (1.09–2.01) | 1.49 (1.06–2.09) | |
| ICD | 83 | 1851.0 | 44.8 | 1.78 (1.40–2.25) | 1.78 (1.34–2.37) |
CIED indicates cardiac implantable electronic device; HR, hazard ratio; ICD, implantable cardioverter‐defibrillator; and IR, incidence rate.
Model 1: Unadjusted.
Model 2: Adjusted for age, sex, hypertension, diabetes, dyslipidemia, myocardial infarction, heart failure, atrial fibrillation, cardiomyopathy, congenital heart disease, low income, tobacco smoking, alcohol consumption, and regular physical activity.
Risk of Mental Disorders by Device Type (Pacemaker Versus ICD)
When comparing mental disorder risk between pacemaker and ICD recipients, there was no significant difference in the risk of mental disorders between the 2 groups (HR, 1.09 [95% CI, 0.75–1.59]) (Table 3). For the secondary outcomes, compared with pacemaker recipients, ICD recipients had numerically higher risks of mood disorders (HR, 1.37 [95% CI, 0.79–2.39]) and anxiety/stress‐related/somatoform disorders (HR, 1.16 [95% CI, 0.76–1.76]), but these differences were not statistically significant. Kaplan‐Meier curves showed no significant separation between the 2 groups (Figure 3).
Table 3.
Comparative Risk of Mental Disorders in Pacemaker Versus ICD Recipients
| Outcome | Group | Model 1*, HR (95% CI) | Model 2†, HR (95% CI) |
|---|---|---|---|
| A composite of mood, anxiety, stress‐related, and somatoform disorders | Pacemaker | Reference | Reference |
| ICD | 1.08 (0.78–1.50) | 1.09 (0.75–1.59) | |
| Mood disorders | Pacemaker | Reference | Reference |
| ICD | 1.11 (0.69–1.78) | 1.37 (0.79–2.39) | |
| Anxiety/stress‐related/somatoform disorders | Pacemaker | Reference | Reference |
| ICD | 1.16 (0.81–1.67) | 1.16 (0.76–1.76) |
HR indicates hazard ratio; and ICD, implantable cardioverter‐defibrillator.
Model 1: Unadjusted.
Model 2: Adjusted for age, sex, hypertension, diabetes, dyslipidemia, myocardial infarction, heart failure, atrial fibrillation, cardiomyopathy, congenital heart disease, low income, tobacco smoking, alcohol consumption, and regular physical activity.
Figure 3. Kaplan‐Meier survival curves for mental disorders: PM vs ICD.
Kaplan‐Meier curves demonstrating the cumulative incidence of mental disorders among individuals stratified into PM recipients and ICD recipients. ICD indicates implantable cardioverter‐defibrillator; and PM, pacemaker.
Time‐Varying Risk Analysis
The increased risk of mental disorders associated with CIED implantation was most pronounced during the early postimplantation period (Table 4). Within the first 2 years after the index date, individuals with CIEDs had a significantly higher risk of experiencing the primary outcome compared with those without devices (HR, 1.95 [95% CI, 1.45–2.62]). Although the relative risk declined after the first 2 years, it remained significantly elevated even beyond 2 years postimplantation (HR, 1.54 [95% CI, 1.13–2.11]). A similar time‐dependent pattern was observed for each disorder type. During the first 2 years following implantation, the risk of developing mood disorders was significantly higher in the CIED group than in controls (HR, 2.70 [95% CI, 1.73–4.21]); notably, this elevated risk persisted beyond 2 years (HR, 1.83 [95% CI, 1.14–2.95]). For anxiety/stress‐related/somatoform disorders, the HR was 1.99 (95% CI, 1.45–2.75) in the first 2 years postimplantation, and remained increased beyond 2 years (HR, 1.44 [95% CI, 1.01–2.06]).
Table 4.
Time‐Varying Risk of Mental Disorders After CIED Implantation
| Follow‐up period and outcome | Group | Events, n | Person‐years | IR | Model 1*, HR (95% CI) | Model 2†, HR (95% CI) |
|---|---|---|---|---|---|---|
| ≤2 y after implantation | ||||||
| A composite of mood, anxiety, stress‐related, and somatoform disorders | No CIED | 230 | 7730.5 | 29.8 | Reference | Reference |
| CIED | 92 | 1441.3 | 63.8 | 2.14 (1.68–2.72) | 1.95 (1.45–2.62) | |
| Mood disorders | No CIED | 78 | 7963.0 | 9.8 | Reference | Reference |
| CIED | 43 | 1541.3 | 27.9 | 2.85 (1.96–4.14) | 2.70 (1.73–4.21) | |
| Anxiety/stress‐related/somatoform disorders | No CIED | 194 | 7779.1 | 24.9 | Reference | Reference |
| CIED | 76 | 1466.1 | 51.8 | 2.07 (1.59–2.70) | 1.99 (1.45–2.75) | |
| >2 y after implantation | ||||||
| A composite of mood, anxiety, stress‐related, and somatoform disorders | No CIED | 260 | 8741.6 | 29.7 | Reference | Reference |
| CIED | 61 | 1493.0 | 40.9 | 1.37 (1.04–1.81) | 1.54 (1.13–2.11) | |
| Mood disorders | No CIED | 93 | 9292.0 | 10.0 | Reference | Reference |
| CIED | 25 | 1624.3 | 15.4 | 1.53 (0.99–2.39) | 1.83 (1.14–2.95) | |
| Anxiety/stress‐related/somatoform disorders | No CIED | 214 | 8899.7 | 24.0 | Reference | Reference |
| CIED | 51 | 1546.7 | 33.0 | 1.37 (1.01–1.86) | 1.44 (1.01–2.06) | |
CIED indicates cardiac implantable electronic device; HR, hazard ratio; and IR, incidence rate.
Model 1: Unadjusted.
Model 2: Adjusted for age, sex, hypertension, diabetes, dyslipidemia, myocardial infarction, heart failure, atrial fibrillation, cardiomyopathy, congenital heart disease, low income, tobacco smoking, alcohol consumption, and regular physical activity.
Sensitivity Analysis
The characteristics of each group after propensity score matching are presented in Table S5. After matching, all covariates used for matching were well balanced between the no‐CIED and CIED groups, with absolute standardized mean difference <0.1. After propensity score matching, CIED recipients still had a 1.69‐fold higher risk of overall mental disorders compared with controls (Table S6). For the secondary outcomes, CIED recipients had higher risks of mood disorders (HR, 2.00 [95% CI, 1.27–3.15]) and anxiety/stress‐related/somatoform disorders (HR, 1.55 [95% CI, 1.14–2.11]), compared with controls. When stratified by device type, the adjusted HRs were 1.59 (95% CI, 1.10–2.29) for pacemaker recipients and 1.76 (95% CI, 1.27–2.45) for ICD recipients (Table S7). For the secondary outcomes, pacemaker recipients had numerically higher risks of mood disorders and anxiety/stress‐related/somatoform disorders than controls, but these differences were not statistically significant. In contrast, ICD recipients had significantly higher risks of both secondary outcomes than controls. In additional recurrent‐event analyses using an Andersen‐Gill model, CIED implantation was associated with a higher rate of repeated mental disorder–related encounters compared with no CIED (adjusted HR, 2.34 [95% CI, 1.51–3.64] for the composite outcome). Similar associations were observed for mood disorders (adjusted HR, 2.30 [95% CI, 1.31–4.02]) and anxiety/stress‐related/somatoform disorders (adjusted HR, 2.49 [95% CI, 1.52–4.10]) (Table S8). When stratified by device type, the magnitude of association was numerically greater in ICD recipients than pacemaker recipients (Table S9).
Subgroup Analyses
The association between CIED implantation and incident mental disorders was consistent across subgroups (Figure S2). When stratified by age groups (20–29 years versus 30–39 years), there was no evidence of effect modification (P for interaction=0.298 for the composite outcome, 0.410 for mood disorders, and 0.194 for anxiety/stress‐related/somatoform disorders). Similarly, the relationship between CIED implantation and mental disorder risk did not differ by sex, smoking, drinking, and low income. However, significant interactions were observed for BMI and regular exercise in the 2‐group analysis comparing overall CIED recipients with controls. The increase in risk associated with CIED implantation was more pronounced among those with a BMI <25 kg/m2 than among those with a BMI ≥25 kg/m2 (P for interaction=0.045 for the composite outcome). Moreover, it was also more pronounced among those who engaged in regular exercise than among those who did not (P for interaction=0.035 for the composite outcome, and 0.019 for anxiety/stress‐related/somatoform disorders). When the CIED group was further divided into pacemaker and ICD subgroups, the overall findings remained consistent, but no significant interactions were identified (Table S10).
DISCUSSION
In this nationwide population‐based study of young adults, CIED implantation was associated with a higher risk of developing subsequent mental disorders. The main findings of our analysis are as follows. (1) Among adults aged 20 to 39 years, implantation of either a pacemaker or an ICD was associated with an increased incidence of mental disorders compared with no device. (2) There was no significant difference in the risk of mental disorders between pacemaker and ICD recipients. (3) Although the excess risk of mental disorders was most pronounced within the first 2 years following device implantation, the risk remained significantly elevated even beyond 2 years of follow‐up. (4) These associations remained consistent across sensitivity analyses using propensity score matching and subgroup analyses.
Data on the relationship between CIED implantation and mental health have been relatively limited to date. 19 The psychological impact of ICD therapy has been studied more extensively than that of pacemaker therapy, likely because ICD recipients often have more severe underlying cardiac conditions and must live with the possibility of painful shock therapies. 20 , 21 , 22 Accordingly, prior reports have documented significant anxiety and depression in patients with an ICD, often attributing these issues to fear of shocks and awareness of their life‐threatening cardiac conditions. In contrast, there has been a paucity of research on psychological outcomes after pacemaker implantation. Some studies have reported a higher prevalence of anxiety and depressive symptoms in individuals with pacemakers; 23 nonetheless, these findings were based largely on self‐reported symptoms or screening questionnaires and may not reflect the actual incidence of clinically diagnosed mental disorders. Additionally, the prevalence of depression was lower in patients with pacemakers than in those with ICDs. 23 , 24 This study defined mental disorders using ICD‐10‐CM codes, which likely allowed us to capture clinically diagnosed outcomes beyond subjective symptoms. 25 Notably, we found that both pacemaker and ICD recipients had an increased risk of mental disorders compared with individuals without CIEDs. Our study extends the existing literature by demonstrating that even pacemaker recipients who may have different underlying disease profiles than ICD recipients experience a significantly elevated risk of developing mental disorders compared with individuals without CIEDs.
Another noteworthy finding was that the elevated risk of mental disorders among CIED recipients persisted beyond the immediate postprocedural period. We observed the most significant relative risk within the first 2 years postimplantation; nonetheless, a considerable risk difference remained even in later years compared with individuals without devices. Some previous studies with shorter follow‐up durations have reported improvements in patient‐reported psychological well‐being within the first year after ICD implantation. 22 , 26 For instance, a prospective Korean survey noted that anxiety and depressive symptoms began to improve as early as 1 month postimplant, with further alleviation by 6 to 12 months. 26 Similarly, a meta‐analysis reported that self‐reported anxiety levels tended to decrease around 6 months after ICD implantation. 22 However, these investigations were limited by follow‐ups of <1 year, making it difficult to assess the long‐term trajectory of mental health in patients with a CIED. Conversely, a recent 5‐year longitudinal study of patients with genetic heart disease who received an ICD found overall improvements in anxiety and depression scores over time but also considerable individual variability in psychological outcomes. 27 Our findings are consistent with the notion that average psychological distress may decrease over time following device implantation. Nevertheless, young CIED recipients remained at a significantly higher risk of clinically diagnosed mental disorders several years postimplant, with a median follow‐up of 5.3 years, which is longer than in most prior studies. This persistent long‐term risk underscores the importance of continuous mental health monitoring and support, emphasizing that initial psychological reactions should not be assumed to resolve spontaneously.
We specifically examined young individuals, a group in which psychological responses to CIEDs are particularly pronounced. Age appears to be an important factor in the psychosocial impact of ICDs, because earlier studies identified younger age as a risk factor for heightened distress among ICD recipients. For example, a European cohort study of patients with ICDs found that those aged <60 years reported significantly greater psychological distress than did older patients. 6 Another study focusing on ICD recipients in early adulthood observed declines in various aspects of psychosocial functioning after device implantation, largely driven by reduced perceived physical functioning, worse health status, and lower overall life satisfaction. 28 In these analyses, younger patients were more prone to anxiety and dissatisfaction with their devices than older patients. In our subgroup analyses, the association between CIED implantation and incident mental disorders was more pronounced among individuals with a BMI <25 kg/m2 and among those who engaged in regular exercise. These subgroup findings should be interpreted cautiously given multiple comparisons and the exploratory nature of interaction testing. One possible explanation is that, in relatively lean and physically active young adults, the perceived impact of implantation on daily activities is greater, which may contribute to a larger increase in mental disorder risk. In addition to age, experiencing ICD shocks is known to adversely influence mental health, significantly increasing the likelihood of developing depression or anxiety. 22 , 29 , 30 Approximately 38% of ICD recipients experience at least 1 appropriate or inappropriate shock within 5 years of implantation. 31 In contrast, in our head‐to‐head comparison between pacemaker and ICD recipients, there was no significant difference in the risk of mental disorders between the 2 device groups (Table 3 and Figure 3). Although we observed no statistically significant differences between pacemaker and ICD recipients, the confidence intervals were wide; therefore, clinically meaningful differences cannot be excluded. This finding suggests that, in this young population, the distress related to undergoing device implantation itself, such as altered body image, psychological burden, and perceived social stigma, may play a larger role than device type or shock events. Nevertheless, most psychological interventions to date have focused on ICD recipients, and interventions specifically targeting pacemaker recipients remain limited. 32 Our findings support the need for more comprehensive psychological care that also includes pacemaker recipients.
Addressing psychological distress in patients with CIEDs also positively influences cardiovascular outcomes. 33 , 34 Mental health conditions, such as anxiety and depression, have been linked to worse clinical outcomes in patients with cardiac patients, including higher mortality in those with ICDs. 33 Importantly, there is evidence that depression in patients with ICDs is associated with an increased risk of all‐cause death. 35 , 36 Therefore, routine screening for mental disorders and providing appropriate interventions, such as counseling, psychiatric care, or peer support programs, should be considered integral components of care for young patients living with CIEDs. Early identification and management of psychological distress may potentially improve mental well‐being and cardiac prognosis in this population.
Compared with previous studies, our investigation offers several significant advantages. By leveraging a large nationally representative cohort and real‐world clinical data, we could make more rigorous adjustments for potential confounders, apply time‐varying risk analyses, and perform subgroup analyses stratified by age and sex. Additionally, the large sample size enabled us to analyze pacemakers and ICD recipients separately, providing device‐specific risk estimates that have previously been underexplored in younger populations. These methodological strengths allowed us to derive robust and generalizable conclusions on the association between CIED implantation and mental health in young adults. Despite its strengths and valuable implications, this study presented some limitations. First, because this was an observational cohort study using administrative data, residual confounding factors may have been present. We adjusted for many known confounders; however, unmeasured factors, such as familial support systems, personality traits, and other social determinants of health, could have influenced both the likelihood of receiving a CIED and the risk of developing mental health issues. Second, the NHIS database does not contain information on certain device‐related events, such as ICD shocks or device malfunctions, which could directly affect psychological outcomes. The absence of these data indicated that we could not analyze their contributions to mental health risks. Third, our study population was limited to adults aged 20 to 39 years, and direct comparisons with other age groups were not possible. Although prior study has suggested greater psychological distress in ICD recipients aged <60 years, the age range differs from that of our cohort. Further studies directly comparing young adults with older patients are needed to clarify age‐related differences in psychological burden after CIED implantation. Fourth, because claims data do not capture symptom severity, remission, or episode boundaries, clinically meaningful recurrence of mental disorders cannot be adjudicated. Diagnostic codes may be repeatedly submitted during routine follow‐up visits, including medication refills, and therefore recurrent claims‐based events should not be interpreted as discrete clinical relapses. Accordingly, we prespecified time to the first incident diagnosis as the primary end point. We additionally performed a recurrent‐event analysis using an Andersen‐Gill model, and the results were directionally consistent with the primary analysis (Table S8). However, these findings should be interpreted as the burden of repeated mental health‐related health care encounters rather than clinically adjudicated recurrences. Our incident definition requiring ≥2 claims within a 12‐month interval was designed to improve specificity for incident onset. Given that requiring ≥2 claims may miss milder cases diagnosed or treated in a single encounter, our findings likely reflect clinically recognized disorders with sustained care. Finally, our analysis was conducted in a relatively ethnically homogeneous Korean population. Caution is warranted when generalizing these findings to more ethnically diverse populations or other health care systems, because cultural perceptions of devices and the willingness to report mental health symptoms may vary.
CONCLUSIONS
Among young adults, implantation of either a pacemaker or an ICD was associated with a significantly increased risk of developing mental disorders, including both mood disorders and anxiety/stress‐related/somatoform disorders. There was no significant difference in mental disorder risk between pacemaker and ICD recipients. Moreover, this elevated risk persisted for >2 years after device implantation. These findings underscore the importance of proactive mental health screening and early intervention as a part of the comprehensive care of young individuals receiving CIEDs.
Sources of Funding
This study was supported by the National Research Foundation of Korea grant funded by the Korea government (The Ministry of Science and ICT) (number RS‐2024‐00449868 and number RS‐2024‐00438808).
Disclosures
None.
Supporting information
Tables S1–S10
Figures S1–S2
Acknowledgments
None.
This article was sent to William W. Aitken, MD, Associate Editor, for review by expert referees, editorial decision, and final disposition.
Supplemental Material is available at https://www.ahajournals.org/doi/suppl/10.1161/JAHA.125.046715
For Sources of Funding and Disclosures, see page 10.
Contributor Information
Heesun Lee, Email: md.sunny.lee@gmail.com.
Jun‐Bean Park, Email: nanumy1@gmail.com.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Tables S1–S10
Figures S1–S2