Impact of bedrest on cardiovascular events and complications associated with temporary pacemakers in patients waiting for permanent pacemaker implantation
These authors take responsibility for all aspects of the reliability and freedom from bias of the data presented and their discussed interpretation.
Abstract
Background
Patients with a temporary pacemaker (TPM) for bradycardias are required to maintain bedrest until permanent pacemakers (PPMs) are implanted because of the development of Adams–Stokes syndrome, worsening heart failure, or complications associated with TPMs is anticipated. However, bedrest may be detrimental in patients because it leads to disuse syndrome. This study examined whether bedrest could decrease the incidence of cardiovascular events or complications associated with TPMs in patients waiting for PPM implantation.
Methods
We conducted a retrospective cohort study on 88 patients who had emergency hospitalization for the treatment of bradycardias, and a TPM was inserted during the waiting period before PPM implantation. We divided patients into two groups according to whether they underwent bedrest (Bedrest Group) or not (Ambulation Group) during the period that patients were supported with TPM. We evaluated whether bedrest was a predictor of adverse events using a logistic regression analysis.
Results
Adverse events occurred in 31 patients (35%). In the univariate analysis, there was no significant difference in the incidence of adverse events between the Bedrest and Ambulation Groups (39% vs. 29%). In the logistic regression analysis, bedrest was not a predictor of adverse events (odds ratio, 1.40; 95% confidence interval, 0.53-3.68, P = .497).
Conclusions
In patients with TPMs for bradyarrhythmias during the waiting period for PPM implantations, bedrest might not prevent adverse events, such as cardiovascular events and complications associated with TPMs.
1 INTRODUCTION
Bradycardia can cause syncope and decompensated heart failure; therefore, we often implant permanent pacemakers (PPMs) in patients with bradycardia.1, 2 While patients with bradyarrhythmias with a temporary pacemaker (TPM) are waiting for PPM implantations, we often order patients to maintain bedrest because of the development of Adams–Stokes syndrome, decompensated heart failure, and complications associated with TPMs, such as a cardiac perforation, TPM-associated infections, and pacing failure, is anticipated.3, 4 In contrast, bedrest is known to cause disuse changes, such as a reduction in muscle strength and exercise capacity, and worsening prognosis in patients.5-7 Therefore, it deems favorable for patients to be released from bedrest. However, it remains controversial as to whether bedrest can help avoid cardiovascular events and complications associated with TPMs during the waiting period for PPM implantation.
Consequently, the present study aimed to evaluate whether bedrest could influence the incidence of cardiovascular events and complications associated with TPMs while patients with a TPM for bradyarrhythmias are waiting for PPM implantations.
2 METHODS
2.1 Study design and population
We performed a retrospective cohort study to confirm whether bedrest could prevent adverse events in patients with a TPM for bradyarrhythmias during the waiting period for PPM implantation. This study consisted of 88 patients who had drug-refractory symptomatic bradyarrhythmias and/or heart failure and emergency admission in our hospital for PPM implantation in patients from April 2011 to May 2020. All patients had a TPM inserted during the waiting period for PPM implantation. We divided (retrospective study) patients into two groups: (1) patients who underwent bedrest during the period that the patients were supported with a TPM (Bedrest Group) and (2) patients who stood or walked during the period that the patients were supported with a TPM (Ambulation Group). It depended on the attending physicians’ decision whether patients were kept on bedrest or not during the period. We checked for all adverse events that occurred during the period that the patients were supported with a TPM. This study was performed in accordance with the Declaration of Helsinki and approved by the research ethics committee of Tokai University (20R-304).
2.2 Adverse events and complications
In this study, adverse events were defined as death, decompensated heart failure, and complications associated with TPMs, such as a cardiac perforation, pacing failure, and TPM-associated infections. The criteria for TPM-associated infections were as follows: (1) There was at least one finding of an infection among the following situations in which fever (body temperature >38.3°C), leukocytosis (white blood cell count >12000/μL), increased plasma C-reactive protein (CRP) level (>2 standard deviation above the normal value), or positive blood culture were observed in their examinations. (2) There were no findings of other infections, except for TPM-associated infections. (3) The attending physicians suspected the development of TPM-associated infections in the patients and performed interventions, such as removal of the catheter, exchange to a new catheter, change of antibiotics, or postponement of PPM implantation.8 Patients’ medical records were retrospectively reviewed, and the investigational items were collected, including age, sex, body mass index (BMI), types of arrhythmias (atrioventricular block [AVB], sick sinus syndrome [SSS], and bradycardic atrial fibrillation [AF]), symptoms of bradyarrhythmias (syncope and heart failure), the insertion sites of TPMs, minimal heart rate, pacing threshold, sensing threshold, and time of TPM insertion. In this study, heart failure was defined as a brain natriuretic peptide (BNP) level ≥80 pg/mL or presence of symptoms caused by heart failure.9 We also checked the coronary risk factors (smoking, hypertension, diabetes mellitus, and dyslipidemia), medications (diuretics, antiarrhythmic drugs, beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and calcium channel blockers), blood tests (BNP, hemoglobin [Hb], estimated glomerular filtration rate, CRP, HbA1c, LDL-cholesterol, HDL-cholesterol, and triglycerides), echocardiography (left ventricular diastolic diameter [LVDd] and left ventricular ejection fraction [LVEF]) during hospitalization, duration from the hospitalization to the device implantation, and whether patients underwent bedrest. We also determined all adverse events and details in patients during the period that patients were supported with a TPM from their medical records (deaths, cardiovascular events, and complications associated with TPMs).
2.3 Statistical analysis
Data are presented as mean ±standard deviation or number (%). We used an unpaired t-test for comparisons of continuous variables and a chi-square test for comparisons of nominal variables between the two groups. We estimated the 95% confidence intervals for the main results. All tests were assessed at a significance level of a P-value <.05. Statistical analyses were performed using SPSS version 16.0 software (SPSS Inc).
First, we compared the Bedrest and Ambulation Groups in terms of adverse events and baseline characteristics with the abovementioned statistical analyses. Next, to select the covariates for the logistic regression analysis, we divided the patients into two groups according to whether they had an adverse event or not (Event (+) Group and Event (−) Group). We also compared the two groups with the abovementioned statistical analyses and selected the items in which there were significant differences between the two groups to use as covariates. With the covariates and whether they underwent bedrest or not, we performed the logistic regression analysis.
3 RESULTS
3.1 Clinical characteristics and results of the study patients
Table 1 shows the demographic and clinical data of the total study population. The mean age was 80 ± 10 years, and 49% (43/88) of the patients were male. Moreover, 69% (61/88) of the patients had atrioventricular block. One patient had both AVB and SSS. Furthermore, 63% (55/88) of patients had syncope before admission. Almost all patients had a TPM inserted via the jugular vein. The average duration of the TPM insertion was 8 ± 8 days. The TPM catheters were inserted on the right ventricular septal side, and antibiotics have been administered during the waiting period for PPM implantation in all patients. The majority of patients had mild renal dysfunction and preserved left ventricular systolic function. The average time from hospitalization to pacemaker implantation was 9 ± 8 days. Adverse events occurred in 31 patients (31/88, 35%).
| Total (n = 88) | Bedrest Group (n = 54) | Ambulation Group (n = 34) | P value | |
|---|---|---|---|---|
| Age (y.o.) | 80 ± 10 | 81 ± 9 | 77 ± 10 | .046 |
| Sex(M/F), n (%) | 43 (49) | 25 (46) | 18 (53) | .544 |
| BMI | 22.2 ± 4.1 | 21.6 ± 4.4 | 23.3 ± 3.1 | .050 |
| Arrhythmia | ||||
| Atrioventricular block, n (%) | 61 (69) | 38 (70) | 23 (68) | .787 |
| Sick sinus syndrome, n (%) | 25 (28) | 16 (30) | 9 (26) | .749 |
| Bradycardic Af, n (%) | 3 (3) | 1 (2) | 2 (6) | .331 |
| Symptoms due to bradyarrhythmias | ||||
| Syncope, n (%) | 55 (63) | 35 (65) | 20 (59) | .572 |
| Heart failure, n (%) | 81 (92) | 51 (94) | 30 (88) | .256 |
| TPM insertion | ||||
| Jugular vein approach, n (%) | 83 (94) | 49 (91) | 34 (100) | .081 |
| Femoral vein approach, n (%) | 5 (6) | 5 (9) | 0 (0) | .081 |
| Minimal heart rate (/min) | 61 ± 10 | 62 ± 11 | 59 ± 8 | .246 |
| TPM pacing threshold (V) | 1.5 ± 0.4 | 1.5 ± 0.5 | 1.5 ± 0.2 | .862 |
| TPM sensing threshold (mV) | 0.9 ± 0.3 | 0.9 ± 0.3 | 0.9 ± 0.3 | .524 |
| Time of TPM insertion (days) | 8 ± 8 | 9 ± 8 | 7 ± 6 | .470 |
| Coronary risk factor | ||||
| Smoking, n (%) | 28 (32) | 13 (24) | 15 (44) | .049 |
| Hypertension, n (%) | 59 (67) | 38 (70) | 21 (62) | .403 |
| Diabetes mellitus, n (%) | 28 (32) | 18 (33) | 10 (29) | .701 |
| Dyslipidemia, n (%) | 24 (27) | 14 (26) | 10 (29) | .721 |
| Medications | ||||
| Diuretics, n (%) | 37 (42) | 23 (43) | 14 (41) | .896 |
| Anti-arrythmiac drugs, n (%) | 1 (1) | 1 (2) | 0 (0) | .614 |
| Βeta-blockers, n (%) | 6 (7) | 3 (6) | 3 (9) | .427 |
| ACE-Is, n (%) | 5 (6) | 3 (6) | 2 (6) | .645 |
| ARBs, n (%) | 36 (41) | 21 (39) | 15 (44) | .627 |
| CCBs, n (%) | 38 (43) | 27 (50) | 11 (32) | .104 |
| Blood exam | ||||
| BNP (pg/mL) | 601 ± 1001 | 734 ± 1220 | 390 ± 394 | .119 |
| Hemoglobin (g/dL) | 12.7 ± 2.0 | 12.6 ± 1.8 | 13.0 ± 2.2 | .347 |
| eGFR (mL/min/1.73m2) | 44.2 ± 20.4 | 42.2 ± 17.6 | 47.3 ± 23.8 | .261 |
| CRP (mg/dL) | 0.901 ± 1.693 | 0.815 ± 1.452 | 1.038 ± 2.011 | .553 |
| HbA1c (%) | 6.1 ± 0.9 | 6.0 ± 0.9 | 6.3 ± 1.0 | .240 |
| LDL-cholesterol (mg/dL) | 107 ± 29 | 105 ± 27 | 109 ± 31 | .517 |
| HDL-cholesterol (mg/dL) | 52 ± 13 | 52 ± 13 | 51 ± 12 | .634 |
| Triglyceride (casual) (mg/dL) | 118 ± 79 | 115 ± 81 | 123 ± 75 | .670 |
| Echocardiography | ||||
| LVDd (mm) | 46 ± 6 | 45 ± 6 | 47 ± 7 | .173 |
| LVEF, n (%) | 59 ± 12 | 59 ± 12 | 58 ± 10 | .862 |
| Time from the hospitalization to the implantation (days) | 9 ± 8 | 9 ± 9 | 8 ± 6 | .413 |
| Adverse event, n (%) | 31 (35) | 21 (39) | 10 (29) | .365 |
Note
- Continuous values are reported as the mean ± SD.
- Abbreviations: ACE-I, angiotensin-converting enzyme inhibitor; Af, atrial fibrillation; ARB, angiotensin receptor blocker; BMI, body mass index; BNP, brain natriuretic peptide; CCB, calcium channel blocker; CRP, C-reactive protein, LVDd, left ventricular diastolic diameter; eGFR, estimated glomerular filtration rate; LVEF, and left ventricular ejection fraction; TPM, temporary pacemaker.
Fifty-four patients (54/88, 61%) underwent bedrest during the period that the patients were supported with a TPM. The average age in the Bedrest Group was older than that in the Ambulation Group. There were no significant differences in sex, BMI, type of arrhythmia, symptoms due to bradyarrhythmias, insertion site of the TPM, minimal heart rate, TPM pacing and setting thresholds, time of TPM insertion, coronary risk factors, medications, blood tests, LVDd, LVEF, and time from hospitalization to the implantation, except for age and smoking, between the Bedrest and Ambulation Groups. Adverse events occurred in 21 patients in the Bedrest Group (21/54, 39%) and ten patients in the Ambulation Group (10/34, 29%). There were no significant differences in the incidence of adverse events between the two groups.
3.2 Adverse events and complications
Table 2 shows the details of the adverse events (31/88, 35%) in the study patients. No patients died or had cardiac perforations during the period that the patients were supported with a TPM. Moreover, 28 patients developed complications associated with TPM. Because of TPM-associated infections, PPM implantation was postponed in five patients. The incidence of complications associated with TPM in the Bedrest Group was higher than that in the Ambulation Group (35%, 19/54, vs. 26%, 9/34). However, there was no significant statistical difference between the two groups.
| Total (n = 31) | Bedrest Group (n = 21) | Ambulation Group (n = 10) | ||
|---|---|---|---|---|
| Death | n | 0 | 0 | 0 |
| Decompensated heart failure | n | 3 | 2 | 1 |
| Complications associated with TPM | n | 28 | 19 | 9 |
| Cardiac perforation | n | 0 | 0 | 0 |
| Pacing failure | n | 16 | 9 | 7 |
| TPM associated infection | n | 12 | 10 | 2 |
| Total | n | 31 | 21 | 10 |
- Abbreviation: TPM, temporary pacemaker.
3.3 Predictors of adverse events
We evaluated whether bedrest was a predictive factor of adverse events in study patients with a logistic regression analysis. To determine the covariates for the analysis to determine whether patients would undergo bedrest or not, we compared the differences between the two groups divided by the presence or absence of adverse events (Table 3). Accordingly, we added (1) the time of TPM insertion and (2) diabetes mellitus as covariates into the analysis because the two items significantly differed between the two groups. Table 4 shows the results of the logistic regression analysis of the predictors of the onset of adverse events. In the results, bedrest was not an independent predictor of the occurrence of adverse events during the waiting period for PPM implantation (odds ratio, 1.40; 95% confidence interval, 0.53-3.68; P = .497).
| Total (n = 88) | Event (+) Group (n = 31) | Event (-) Group (n = 57) | P value | |
|---|---|---|---|---|
| Age (y.o.) | 80 ± 10 | 80 ± 11 | 80 ± 9 | .725 |
| Sex (M/F), n (%) | 43 (49) | 16 (52) | 27 (47) | .704 |
| BMI | 22.2 ± 4.1 | 22.0 ± 4.9 | 22.3 ± 3.6 | .730 |
| Arrhythmia | ||||
| Atrioventricular block, n (%) | 61 (69) | 24 (77) | 37 (65) | .224 |
| Sick sinus syndrome, n (%) | 25 (28) | 6 (19) | 19 (33) | .165 |
| Bradycardic Af, n (%) | 3 (3) | 1 (3) | 2 (4) | .718 |
| Symptoms due to bradyarrhythmias | ||||
| Syncope, n (%) | 55 (63) | 22 (71) | 33 (58) | .226 |
| Heart failure, n (%) | 81 (92) | 30 (97) | 51 (89) | .219 |
| TPM insertion | ||||
| Jugular vein approach, n (%) | 83 (94) | 29 (94) | 54 (95) | .581 |
| Femoral vein approach, n (%) | 5 (6) | 2 (6) | 3 (5) | .581 |
| Minimal heart rate (/min) | 61 ± 10 | 61 ± 10 | 61 ± 10 | .971 |
| TPM pacing threshold (V) | 1.5 ± 0.4 | 1.6 ± 0.4 | 1.5 ± 0.4 | .449 |
| TPM sensing threshold (mV) | 0.9 ± 0.3 | 0.9 ± 0.3 | 0.9 ± 0.3 | .836 |
| Time of TPM insertion (days) | 8 ± 8 | 10 ± 9 | 7 ± 6 | .032 |
| Coronary risk factor | ||||
| Smoking, n (%) | 28 (32) | 7 (23) | 21 (37) | .170 |
| Hypertension, n (%) | 59 (67) | 20 (65) | 39 (68) | .710 |
| Diabetes mellitus, n (%) | 28 (32) | 14 (45) | 14 (25) | .047 |
| Dyslipidemia, n (%) | 24 (27) | 7 (23) | 17 (30) | .466 |
| Medications | ||||
| Diuretics, n (%) | 37 (42) | 16 (52) | 21 (37) | .180 |
| Anti-arrythmiac drugs, n (%) | 1 (1) | 0 (0) | 1 (2) | .648 |
| Βeta-blockers, n (%) | 6 (7) | 1 (3) | 5 (9) | .306 |
| ACE-Is, n (%) | 5 (6) | 2 (6) | 3 (5) | .581 |
| ARBs, n (%) | 36 (41) | 14 (45) | 22 (39) | .550 |
| CCBs, n (%) | 38 (43) | 16 (52) | 22 (39) | .239 |
| Blood exam | ||||
| BNP (pg/mL) | 601 ± 1001 | 582 ± 545 | 611 ± 1177 | .899 |
| Hemoglobin (g/dL) | 12.7 ± 2.0 | 12.9 ± 1.8 | 12.6 ± 2.0 | .586 |
| eGFR (mL/min/1.73m2) | 44.2 ± 20.4 | 42.6 ± 22.9 | 45.1 ± 18.9 | .591 |
| CRP (mg/dL) | 0.901 ± 1.693 | 0.922 ± 1.488 | 0.889 ± 1.795 | .933 |
| HbA1c (%) | 6.1 ± 0.9 | 6.3 ± 1.1 | 6.0 ± 0.8 | .295 |
| LDL-cholesterol (mg/dL) | 107 ± 29 | 112 ± 30 | 104 ± 27 | .224 |
| HDL-cholesterol (mg/dL) | 52 ± 13 | 48 ± 13 | 53 ± 13 | .114 |
| Triglyceride (casual) (mg/dL) | 118 ± 79 | 142 ± 109 | 106 ± 53 | .041 |
| Echocardiography | ||||
| LVDd (mm) | 46 ± 6 | 46 ± 5 | 46 ± 7 | .679 |
| LVEF, n (%) | 59 ± 12 | 59 ± 12 | 58 ± 11 | .907 |
| Time from the hospitalization to the implantation (days) | 9 ± 8 | 11 ± 9 | 8 ± 7 | .046 |
| Bedrest, n (%) | 50 (57) | 21 (68) | 29 (51) | .365 |
Note
- Continuous values are reported as the mean ± SD.
- Abbreviations: ACE-I, angiotensin-converting enzyme inhibitor; Af, atrial fibrillation; ARB, angiotensin receptor blocker; BMI, body mass index; BNP, brain natriuretic peptide; CCB, calcium channel blocker; CRP, C-reactive protein, LVDd, left ventricular diastolic diameter; eGFR, estimated glomerular filtration rate; LVEF, and left ventricular ejection fraction; TPM, temporary pacemaker.
| Predictor | logistic regression analysis | ||
|---|---|---|---|
| OR | 95% CI | P value | |
| Bedrest | 1.40 | 0.53-3.68 | .497 |
| Time of the temporary pacemaker insertion | 1.07 | 1.00-1.15 | .039 |
| Diabetes mellitus | 2.85 | 1.09-7.47 | .033 |
- Abbreviations: CI, confidential interval; OR, odds ratio.
4 DISCUSSION
The major findings of this study were as follows. There was no significant difference in the occurrence of adverse events between the Bedrest and Ambulation Groups. Moreover, bedrest was not a predictor of the occurrence of adverse events in the logistic regression analysis. These findings suggested that bedrest may not prevent adverse events in patients who have bradyarrhythmias with a TPM while they are waiting for PPM implantation.
PPM implantations are greatly useful for patients with unstable arrhythmias. Cardiac syncope with Adams–Stokes syndrome has a poorer prognosis than syncope due to other causes and has a high mortality of approximately 20%–30%.2 It is recommended in the Japan Circulation Society (JCS) guidelines on nonpharmacological treatment of arrhythmias to implant a PPM for AVB, bi- or trifascicular block, SSS, bradycardic AF causing syncope, or heart failure.10 In addition, TPM insertion has also been shown to be favorable in that it provides temporary heart rate support in patients with syncope, heart failure, and risk of cardiac death until a PPM is implanted.11 In contrast, a previous study showed that the complication rate associated with a TPM was 36.7%. The details were that pacing failure occurred in 9.5% of patients, infections in 4.8%, and cardiac perforations in 1.6%.3 Even worse, cardiac perforations caused by a device can affect mortality and extension of hospitalization.12, 13 In this study, complications associated with a TPM was the most frequent adverse event during the period that the patients were supported with a TPM (Table 2). Because the development of cardiac syncope, decompensated heart failure, and various adverse events associated with TPMs, as mentioned above, is anticipated, we are apt to oblige patients to maintain bedrest until PPM implantation. However, our research results showed that bedrest did not influence the prevalence of adverse events.
In contrast, although bedrest might reduce the metabolic demand on the heart and prevent ischemia and arrhythmias during the acute phase, bedrest itself can cause many complications.14 It leads patients to lose approximately 2%-3% of their muscle strength per day.5 Moreover, disuse changes caused by bedrest include not only muscular weakness and joint contractures but also nerve disorders, such as orthostatic disturbances, sleep disruption, deep venous thrombosis, and decline in the exercise capacity. A previous study showed that, in healthy men who maintained bedrest for 20 days, their maximal oxygen consumption decreased from 3.3 to 2.4 L/min.6 Regarding the physical work capacity, 3 weeks of bed rest was the same as 20 years of aging in the same man.15 Another study has shown that, once patients acquire sarcopenia, which is a syndrome associated with a decline in the muscle mass and strength, it can especially increase the mortality risk due to cardiovascular disease.16-18 To the best of our knowledge, there have been no studies that showed that bedrest can have a favorable effect on the clinical course of patients with regard to the prevention of adverse events during the waiting period for PPM implantation. On the contrary, bedrest has been shown to be harmful in patients with cardiovascular disease.15-18
In the JCS/Japan Heart Failure Society guidelines, as soon as the hemodynamics in patients with heart failure become stabilized, they should get out of bed and undergo cardiac rehabilitation.19 The JCS guidelines also indicate that patients with various arrhythmias should receive medical treatment from the cardiovascular team, consisting of not only physicians but also nurses, physical therapists, and clinical engineers.10 Under appropriate management of patients with a TPM for bradyarrhythmias, it might be unnecessary to make patients maintain bedrest during the waiting period for PPM implantation.
4.1 Limitations
There were a couple of limitations to the present study. First, this study did not have a large sample size, especially of patients who had adverse events. Second, the details of the physical capacity, muscle strength, and activities of daily life, such as the Barthel index, in the study patients were not checked. Further, there was no description about the severity of heart failure, such as the NYHA classification, in the medical records.
5 CONCLUSIONS
Bedrest might not prevent cardiovascular events or device complications in patients with a TPM for bradyarrhythmias during the waiting period for PPM implantation.
ACKNOWLEDGMENT
The authors express their special gratitude to Mr John Martin and Enago (www.enago.jp) for the English language review.
CONFLICT OF INTEREST
The authors declare no conflict of interest for this article.
