A randomized trial comparing heparin initiation 6 h or 24 h after pacemaker or defibrillator implantation

Thromboembolic events during the perioperative period in patients undergoing permanent pacemaker implantation

BACKGROUND

Thromboembolism (TE) is one of the most serious complications after pacemaker implantation. It has been demonstrated that several patient characteristics and different pacing modes are related to an increased risk of TE events during long-term follow-up.

HYPOTHESIS

We propose that TE events occurring during the perioperative period of pacemaker implantation may be associated with certain clinical characteristics.

METHODS

The potential risk factors of TE events were analyzed in 406 consecutive patients who underwent pacemaker implantation.

RESULTS

We identified TE events in 11 patients (2.7%) within 7 days after pacemaker implantation. Four of the 11 (36.4%) patients died of complications of TE. Univariate analysis revealed that an age of >75 years (4.56 odds ratio [OR], P = 0.031), hypertension (3.59 OR, P = 0.028), diabetes (8.89 OR, P < 0.001), coronary heart disease (4.8 OR, P = 0.005), atrial fibrillation (AF) (5.68 OR, P = 0.006), persistent AF (10.36 OR, P < 0.001), and a history of stroke or transient ischemic attack (5.62 OR, P = 0.002) were associated with an increased risk of TE events. Multivariate logistic analysis showed that persistent AF (9.8 OR, P < 0.001) was independently associated with TE. The incidence of perioperative TE was not significantly different between patients with single- and dual-chamber pacemakers.

CONCLUSIONS

We found TE events during the perioperative period in patients undergoing pacemaker implantation were not uncommon. Because persistent AF during the perioperative period was the only independent risk factor for perioperative TE, appropriate anticoagulation therapy may be necessary in those patients. © 2012 Wiley Periodicals, Inc. J. Liu, MD, is co-first author. The authors have no funding, financial relationships, or conflicts of interest to disclose.

Implantation of cardiac rhythm devices during concomitant anticoagulation or antiplatelet therapy

Cardiac rhythm devices are increasingly being utilized as the population ages and the incidence of chronic heart failure, bradyarrhythmias and the indications for pacing and prevention of sudden cardiac arrest expand. The number of patients receiving oral anticoagulants and dual antiplatelet therapy is similarly increasing. Implantation of cardiac rhythm devices during concomitant use of oral anticoagulants or antiplatelet regimens poses an increased risk of perioperative bleeding complications. Traditionally, heparin-based bridging protocols have been recommended for such patients to mitigate the bleeding risk while reducing the risk of thrombotic complications. Although the literature is limited, an appraisal of the literature reveals that bridging may not be the best strategy. We review the literature and propose strategies to promote successful perioperative outcomes, while reducing the risk of bleeding or thrombosis during the time of implantation for patients on chronic anticoagulation and antiplatelet therapies.

[Antiplatelet agents increase hemorrhagic risk in patients undergoing a cardiac pacemaker or ICD implantation]

OBJECTIVES

This study was designed to assess the hypothesis that the implantation or the replacement of a cardiac stimulator or defibrillator in patients receiving antiplatelet agents is associated with an increase of the haemorrhagic risk in comparison with patients not receiving antiplatelet agents (control group).

METHODS AND RESULTS

We retrospectively included all the patients undergoing pacemaker or ICD implantation or replacement between January 2007 and May 2010. The primary criterion was the incidence of bleeding complications. In our center, 685 patients were implanted in this period. Two hundred and fourteen (31%) were implanted while taking antiplatelet agents, including 164 (24%) taking aspirin, 31 (4%) taking clopidogrel and 19 (3%) taking the combination aspirin plus clopidogrel, while 471 patients (69%) did not receive antiplatelet agents. The primary criteria was the hemorrhagic complications. Complications were noted in 14 patients out of 471 (3%) not taking antiplatelet agents, in 16 patients out of 214 (7.5%) taking an antiplatelet agent (P=0.004). The complications concerned 13 patients out of 164 taking aspirin (7.9%), one patient out of 31 (3.2%) taking clopidogrel and two patients out of 19 taking the combination aspirin plus clopidogrel (10.5%) (P=0.042 for aspirin vs placebo, NS for all other comparisons). In multivariable analysis, the factors associated with an increase of the heamorrhagic complications were the type of implant (ICD) (OR 3,7; P=0.001) and antiplatelet treatment (OR 2,7; P=0.009).

CONCLUSION

Pacemaker and ICD implantation or replacement in patients taking antiplatelet agents are associated with an increase of the hemorrhagic risk.

No increased bleeding events with continuation of oral anticoagulation therapy for patients undergoing cardiac device procedure

BACKGROUND

Switching warfarin for heparin has been a practice for managing periprocedural anticoagulation in high-risk patients undergoing device-related procedures. We sought to investigate whether continuation of warfarin sodium therapy without heparin bridging is safe and, when it is continued, the optimal international normalized ratio (INR) without increased bleeding risk at time of device-related procedure.

METHODS AND RESULTS

We retrospectively studied 766 consecutive patients taking warfarin long term who underwent device-related procedures. Patients were grouped by treatment: discontinued warfarin (-warfarin, n = 243), no interruption of warfarin (+warfarin, n = 324), and discontinued warfarin with heparin bridging (+heparin, n = 199). The study primary endpoint was systemic bleeding or formation of moderate or severe pocket hematoma within 30 days of the procedure. Thirty-one (4%) patients had bleeding events, including pocket hematoma in 29 patients. The bleeding events occurred more often for +heparin (7.0%) than -warfarin (2.1%) or +warfarin (3.7%, P = 0.029). For +warfarin group, INR of 2.0-2.5 at time of procedure did not increase bleeding risk compared with INR less than 1.5 (3.7% vs 3.4%; P = 0.72), but INR greater than 2.5 increased the bleeding risk (10.0% vs 3.4%; P = 0.029). Concomitant aspirin use with warfarin significantly increased bleeding risk than warfarin alone (5.6% vs 1.4%, P = 0.02). Median length of hospitalization was significantly shorter for +warfarin than +heparin (1 vs 6 days; P < 0.001).

CONCLUSION

Continuation of oral anticoagulation therapy with an INR level of <2.5 does not impose increased risk of bleeding for device-related procedures, although precaution is necessary to avoid supratherapeutic anticoagulation levels.

Morbidity associated with three different antiplatelet regimens in patients undergoing implantation of cardiac rhythm management devices

AIMS

Perioperative management of antiplatelet (AP) therapy in patients undergoing implantation of cardiac rhythm management devices (CRMD) remains an issue of concern that has not been prospectively evaluated in a large series. We sought to describe the morbidity associated with three different AP regimens in this setting.

METHODS AND RESULTS

We conducted a prospective observational study including 849 consecutive patients who were classified in three groups according to the presence of any AP treatment: Group 1 (n= 220): single AP therapy; Group 2 (n= 60): dual AP therapy; and Group 3 (n= 40): oral anticoagulant (OAC) + enoxaparin 'bridging' + AP therapy. Two other groups served as controls: Group 4 (n= 375): no AP or OAC therapy; and Group 5 (n= 154): OAC + enoxaparin 'bridging'. The incidence of pocket haematoma, pocket revisions, hospital stays duration, and unscheduled follow-up visits due to pocket-related complications were compared. Patients on Groups 2, 3 and 5 had significantly higher incidences of pocket haematoma (13.3, 15, and 14.9%, respectively) when compared with Groups 1 and 4 (3.2 and 2.4%, respectively), as well as longer hospital stays and more unscheduled follow-up visits. Of note, only patients on enoxaparin 'bridging' required surgical revision of the pocket. Dual AP therapy (P< 0.001), enoxaparin 'bridging' (P< 0.001) and renal insufficiency (P= 0.02) were independent predictors of pocket haematoma in multivariate analysis.

CONCLUSION

Dual AP therapy and OAC + AP therapy is strongly associated with a significant risk of pocket haematoma, longer hospital stays, and unscheduled follow-up visits. Importantly, surgical revision of the pocket was associated with enoxaparin 'bridging' strategy but was never necessary in patients taking exclusively antiaggregant agents.

[Oral anticoagulation doesn't increase hemorrhagic risk in patients undergoing a cardiac pacemaker or defibrillator implantation]

OBJECTIVES

This study was designed to assess the hypothesis that the implantation or the replacement of a cardiac stimulator or defibrillator in patients receiving oral anticoagulants with an INR≥2 doesn't increase the hemorrhagic risk in comparison with patients for whom the treatment has been interrupted temporarily (INR<2) or with patients not receiving anticoagulants (control group).

PATIENTS AND RESULTS

We performed a retrospective chart review of bleeding complications in all patients undergoing pacemaker or ICD implantation or replacement between January 2007 and may 2009. In this cohort, 43 patients (10%) were implanted with an INR≥2 while 36 patients (8%) were implanted with an INR<2 and 352 patients (82%) didn't receive anticoagulants. No complication (0/36) has been observed in patients having an INR<2, while 3/43 (7%) complications have been observed in patients with an INR≥2 and 13/352 (3.7%) in patients in the control group (p=0.3093). Duration of the hospital stay was similar in the three groups: 6.2 days in patients with an INR<2, 6.8 days in the group with an INR≥2 and 6.2days in the control group (p=0.686).

CONCLUSION

Pacemaker and ICD implantation or replacement without withdrawing of oral anticoagulants and an INR≥2 was not associated with an increase of the hemorrhagic risk.

Peri-procedural anticoagulation and the incidence of haematoma formation after permanent pacemaker implantation in the elderly

BACKGROUND

Haematoma formation is a recognised complication after permanent pacemaker (PPM) implantation. The contribution of peri-procedural anticoagulation to the risk of haematoma formation is unclear.

METHOD

The records of 518 consecutive patients, mean age 76.9±9.8 years, receiving their first PPM (2004-2007) in a single tertiary referral centre were reviewed. Follow-up was complete for 506 patients (97.7%) up to six weeks. Haematomas were diagnosed clinically, and further subdivided according to the need for evacuation.

RESULTS

There were 27 instances of haematoma formation in 25 patients (4.9%) with 19 requiring drainage or evacuation. Twenty-one of the 25 patients who developed a haematoma had stopped warfarin and received bridging therapeutic anticoagulation pre- and post-PPM. The incidence of haematoma was significantly greater in those receiving peri-operative therapeutic anticoagulation (26.9% vs 0.9%, p<0.001), but was unaffected by the use of anti-platelet therapy. Most haematomas developed in patients whose heparin was recommenced within 24 hours of implantation. The development of haematoma post-PPM increased median hospital stay significantly (p<0.001). The main indication for anticoagulation in these patients was atrial fibrillation (79.5%) and most of these patients had a low to intermediate risk of peri-procedural thromboembolic events.

CONCLUSION

Peri-operative therapeutic anticoagulation is associated with more than 25-fold increase in haematoma formation post-pacemaker implantation. The risk-benefit ratio of therapeutic anticoagulation should be carefully considered, particularly in patients with a low risk of thromboembolic events.

Risk of Hematoma Complications After Device Implant in the Clopidogrel Era

Background—

Device implant pocket hematoma is a recognized complication after permanent pacemaker (PM) and implantable cardioverter-defibrillator (ICD) implantation. Pocket hematoma is associated with local discomfort, an increased risk of infection, and may require surgical intervention or lead to lengthier hospital stays. The purpose of the study was to identify the clinical factors associated with hematoma formation after PM or ICD device implantation.

Methods and Results—

The subjects of this prospective observational study were 935 consecutive patients at Beaumont Hospital who underwent implantation of a PM or an ICD. Clinical characteristics and anticoagulant/antiplatelet drug use were recorded. A pocket hematoma was documented in 89 of 935 patients. Significant predictors of device pocket hematoma included ongoing clopidogrel therapy (18.3% on therapy, 10.5% recently discontinued, and 7.9% off therapy; P <0.001) and use of intravenous heparin (22.0% on therapy versus 8.2%; P <0.0001). Patients in whom clopidogrel was discontinued >4 days before device implantation had no hematoma. Hematomas occur more frequently in patients receiving ICDs than those receiving PMs. Device pocket hematoma was associated with an increased median length of hospital stay (4 days [interquartile range, 1 to 9] days with versus 2 days [ interquartile range, 1 to 6] days without hematoma; P =0.004) and increased late complications or surgical intervention.

Conclusions—

The use of clopidogrel or intravenous heparin significantly increased the risk of hematoma at the time of PM or ICD implantation. By withholding clopidogrel before surgery, the excess risk of bleeding complications may be reduced.

[Progress in cardiac pacing]

This review discusses the utility and current status of remote monitoring in patients with cardiac devices in Spain, the different anticoagulation strategies used during device implantation, the surgical replacement and maintenance of pacemakers and defibrillators, and the present and future importance of impedance sensors in cardiac pacing and heart failure management. Finally, there is a summary of the most relevant scientific articles published in the last year.

Perioperative management of anticoagulation during device implantation-the UK perspective

BACKGROUND

Increasing numbers of patients taking oral anticoagulation are presenting for device implantation. Cessation of anticoagulation in the perioperative period may expose patients to increased risk of thromboembolic events, while continuing anticoagulation may increase the risk of bleeding. There are few guidelines or randomized controlled trials to guide perioperative management.

METHODS

We carried out a questionnaire-based study of all cardiologists implanting devices in the United Kingdom to establish if there was consensus on management of anticoagulation in patients undergoing pacemaker implantation.

RESULTS

There is significant variation in management of these patients. Eighty-nine percent of doctors stop oral anticoagulation a mean 3.7 days prior to pacemaker implantation in patients with a mechanical mitral valve, with 94% using heparin to provide preoperative anticoagulation: 58% unfractionated heparin, 40% low molecular weight heparin. The maximum accepted international normalized ratio for implantation ranged from 1.4 to 3 (median 1.8). Postoperatively, 86% restart heparin after a mean 8.5 hours. Only 11% continue oral anticoagulation throughout the implantation period. There is a hierarchy of perceived embolic risk with doctors using progressively less anticoagulation in patients with prosthetic aortic valve, high-risk, and low-risk atrial fibrillation. In contrast, only 7% of implanters stop theinopyridines prior to device implantation in patients with a 2-month-old drug eluting stent.

CONCLUSION

Perioperative anticoagulation management of patients undergoing device procedures is currently performed with little consensus. This emphasizes the need for careful national and international audit of periprocedural anticoagulation management and its associated complications with a view to developing international consensus guidelines. (PACE 2010; 389-393).

[Hemorrhagic risk of different perioperative anticoagulation protocols in patients implanted with a cardiac pacemaker or defibrillator: retrospective analysis in patients implanted in a community hospital]

AIMS

Perioperative management of anticoagulation in patients referred for pacemaker or cardiac defibrillator implantation isn't consensual. Our objective was to evaluate, in a large cohort, hemorrhagic complications in patients having implantation or replacement of a cardiac pacemaker or defibrillator, and to assess perioperative anticoagulation effect on hemorrhagic risk.

METHODS AND RESULTS

A cohort of 461 consecutive patients having implantation or replacement of a cardiac pacemaker or defibrillator has been analyzed. Thirty patients (6,5%) had oral anticoagulants (OAC) switched to heparin/low-molecular-weight heparin, while 76 (16,5%) had their oral anticoagulation disrupted habitually for 48 hours. A total of six over 30 (20%) and two over 76 (2.6%) patients in the bridge and OAC, respectively experienced a pocket hematoma (bridge vs. OAC, p<0.05), while ten over 355 (2.8%) had a pocket hematoma in the control group (bridge vs. control p=0.006). Duration of the hospital stay was longer in the bridge group in comparison with OAC and control groups (9 vs. 7 vs. 6 days, respectively, p=0.006).

CONCLUSION

Oral anticoagulation bridging with heparin or low-molecular-weight heparin is associated with a higher risk of pocket hematoma and a longer duration of hospitalization, in comparison with a strategy allowing a temporary disruption of OAC adapted to the thromboembolic risk.

Implantation of cardiac rhythm devices without interruption of oral anticoagulation compared with perioperative bridging with low-molecular weight heparin

BACKGROUND

Increasing numbers of patients requiring arrhythmia device implantation are taking warfarin. The common practice of warfarin interruption and perioperative bridging with heparin is associated with a high rate of postoperative hemorrhagic complications. We assessed the safety of device implantation without interruption of warfarin therapy.

METHODS

Three patient groups were studied: Group 1 consisted of 117 consecutive patients on long-term warfarin therapy with significant risk of thromboembolism (atrial fibrillation with CHADS(2) score > or =2, mechanical heart valve, recent venous thromboembolism) who underwent arrhythmia device implantation without interruption of warfarin. Group 2 was 117 patients who served as age- and sex-matched controls matched to procedure type not taking warfarin. Group 3 consisted of 38 similar thromboembolic risk historical control patients who underwent interruption of warfarin therapy and bridging with dalteparin before and 24 hours after surgery. Active fixation leads were used by subclavian or axillary vein puncture, with septal fixation in the ventricle in 56% of patients. Hemorrhagic and thromboembolic complications were assessed at discharge and at 7 and 30 days after surgery.

RESULTS

During an 18-month period, 1,562 consecutive adult patients underwent heart rhythm device implantation or replacement. One hundred seventeen of the 447 patients on warfarin were considered high risk and remained on warfarin for their procedure. The mean international normalized ratio in group 1 patients was 2.2 +/- 0.4 (age 79 +/- 11 years, 73 male). Significant hematoma was noted in 9 patients (7.7%), and one required surgical revision (0.9%). Five group 2 patients (control) had significant hematomas (4.3%), none of which required revision (P = .41). In group 3, 9 patients developed significant hematomas (23.7%, P = .012), 3 of whom required reoperation (7.9%, P = .046). There were no deaths, thromboembolic events, cardiac tamponade, or hemothorax in any patient. The only risk factor for hematoma in the warfarin patients was the number of leads implanted.

CONCLUSIONS

Arrhythmia devices can be implanted safely in patients with high thromboembolic risk without interruption of warfarin. This strategy may be associated with reduced risk of significant pocket hematoma compared with dalteparin bridging.

Preparation for pacemaker or implantable cardiac defibrillator implants in patients with high risk of thrombo-embolic events: oral anticoagulation or bridging with intravenous heparin? A prospective randomized trial

AIMS

Current guidelines recommend stopping oral anticoagulation (OAC) and starting heparin infusion before implanting/replacing a pacemaker/implantable cardioverter-defibrillator (ICD) in patients with high risk for thrombo-embolic events. The aim of this study was to demonstrate that the maintenance of OAC during device implantation/replacement is as safe as bridging to intravenous heparin and shortens in-hospital stay.

METHODS AND RESULTS

A cohort of 101 consecutive patients with high risk for embolic events and indication for implant/replacement of a pacemaker/ICD were randomized to two anticoagulant strategies: bridging from OAC to heparin infusion (n = 51) vs. maintenance of OAC to reach an INR = 2 +/- 0.3 at the day of the procedure (n = 50). Haemorrhagic and thrombo-embolic complications were evaluated at discharge, 15 and 45 days after the procedure. A total of 4/51 patients (7.8%) from heparin group and 4/50 (8.0%) from the OAC group developed pocket haematoma following the implant (P = 1.00). One haematoma in each group required evacuation (1.9 vs. 2%, P = 1.00). No other haemorrhagic events or embolic complications developed during the follow-up. Duration of the hospital stay was longer in the heparin group [median of 5 (4-7) vs. 2 (1-4) days; P < 0.001].

CONCLUSION

Implant of devices maintaining OAC is as safe as bridging to heparin infusion and allows a significant reduction of in-hospital stay.

Defibrillation testing in patients with atrial fibrillation

Implantable cardioverter defibrillator implantation in patients with atrial fibrillation (AF) is complicated by the need for anticoagulation during defibrillation testing. In this retrospective study, we evaluated the factors associated with successful cardioversion of AF during ventricular defibrillation testing and the safety of our local anticoagulation protocol.

Atrial fibrillation in patients with implantable defibrillators

Atrial fibrillation (AF) is common in patients who have implantable defibrillators and presents some unique challenges and opportunities. AF burden can be assessed more accurately, allowing for evaluation of therapy efficacy (drugs or ablation). It remains to be shown whether home monitoring of defibrillators to detect and treat AF more quickly can reduce cardiovascular and stroke end points. One major goal will be to reduce inappropriate shocks from atrial fibrillation. Otherwise, the goals of therapy remain the same-reduction of symptoms (including heart failure exacerbation and inappropriate implantable cardioverter defibrillator therapies) by controlling rate or rhythm and anticoagulation for stroke prophylaxis.

Perioperative anticoagulation in patients having implantation of a cardiac pacemaker or defibrillator: a systematic review and practical management guide

BACKGROUND

The perioperative management of anticoagulation in patients who are having implantation of a pacemaker or implantable cardioverter defibrillator (ICD) is a common clinical problem in which best clinical practise is not established.

METHODS

We performed a systematic review of the literature to assess the safety (pocket hematoma risk) and efficacy (thromboembolism risk) of different management strategies. We included studies involving patients who were having pacemaker or ICD implantation whenever a portion of these patients were receiving a coumarin and also assessed pocket hematoma or thromboembolism.

RESULTS

We identified eight studies that assessed two strategies used for perioperative anticoagulation management: interruption of a coumarin and use of bridging anticoagulation with a short-acting heparin; and perioperative continuation of a coumarin. A strategy involving bridging anticoagulation with therapeutic-dose heparin was associated with an incidence of pocket hematoma of 12-20%. A strategy involving perioperative continuation of a coumarin was associated with an incidence of pocket bleeding of 1.9-6.6%. The incidence of thromboembolic events was 0-1%, irrespective of the perioperative anticoagulation strategy used.

CONCLUSION

The perioperative anticoagulation management of patients who require pacemaker or ICD implantation is not established but a strategy involving postoperative bridging with intravenous heparin confers a high risk for bleeding whereas perioperative continuation of a coumarin appears to confer a lower risk for bleeding.

[Strategies for the avoidance and treatment of complications during pacemaker implantation]

The implantation of a pacemaker is the therapy of choice for symptomatic bradyarrhythmias. The perioperative complication rate is low. This article gives an overview on possible complications, their avoidance and treatment.

Complications of Pacemakers and Defibrillators in the Elderly

Within the United States, the elderly population is projected to increase 126% by 2050, making those over the age of 65 the most rapidly growing segment in the population. Permanent pacemakers and defibrillators are important therapies with expanding indications for their use, and older persons constitute the majority of recipients of these devices. Recognizing complications associated with these cardiac devices is essential in caring for patients with them. Complications can be related to the implantation procedure and are most commonly lead dislodgement, pneumothorax, lead perforation, hematoma, and infection. Intrinsic device programming can also result in complications such as pacemaker syndrome, pacemaker-mediated tachycardia, and inappropriate shocks. Extrinsic factors, such as electromagnetic interference and physically manipulating the device, can also result in problems. Recent work suggests that older age, by itself, is not associated with a significant increase in the complication rates from these devices and should not preclude their use.

The frequency and incremental cost of major complications among medicare beneficiaries receiving implantable cardioverter-defibrillators

OBJECTIVES

We aimed to quantify the frequency and nature of early complications after implantable cardioverter-defibrillator (ICD) implantation in general practice, and estimate the incremental costs of those complications to the health care system.

BACKGROUND

Cardioverter-defibrillator implantation rates are rising quickly. Little has been published regarding the outcomes and costs of these procedures in unselected populations.

METHODS

Using Medicare Provider Analysis and Review (MedPAR) files, we identified 30,984 admissions containing procedure codes for new ICD or cardiac resynchronization therapy defibrillator implantation in fiscal year 2003. The frequencies of eight complicating diagnoses during these admissions were determined. Length of stay (LOS) and total hospital costs, derived using whole-hospital cost to charge ratios, were calculated for each admission. The incremental effects of any and each complication on LOS and hospital cost were estimated in multivariable models, adjusting for demographic factors and comorbid conditions.

RESULTS

The mean cost for all admissions was 42,184 dollars (median 37,902 dollars) with mean LOS of 4.7 days (median 2.0 days). One or more complications were coded in 10.8% of admissions, most commonly "mechanical complication of the ICD" and hemorrhage/hematoma. The occurrence of any complication increased adjusted LOS by 3.4 days and costs by 7,251 dollars. Each of the individual complications was associated with highly significant increases in both LOS (1 to 10 days) and hospital cost (5,000 dollars to 20,000 dollars).

CONCLUSIONS

In fiscal 2003, 10.8% of Medicare patients undergoing cardioverter-defibrillator implantation experienced one or more early complications, associated with significant increases in LOS and costs. Efforts to reduce these complications could have significant clinical and financial benefits.

Post-operative use of heparin increases morbidity of pacemaker implantation

AIMS

The objective of this study is to characterize the incidence of peri-operative severe adverse events (AEs) related to the post-operative use of heparin in patients undergoing pacemaker surgery.

METHODS AND RESULTS

We retrospectively compared the outcome of 38 patients with mechanical valves (MVs) and 76 patients with atrial fibrillation (AF) with control cases matched for gender, age, and surgical details. Heparin was systematically used post-operatively in MV patients, but left to clinical judgment in AF patients. The relative risk for severe haemorrhagic AEs was 11 (CI 1.5-81.1, P < 0.01) in the MV group when compared with matched controls and 8 (CI 1.0-62.5, P < 0.05) in the AF group. Overall, the relative risk of heparin use in the post-operative period was 14 (CI 1.88-104, P = 0.0006) and the post-operative stay was prolonged from 7 days in this group when compared with control cases (P < 0.0001).The variables associated with haemorrhage were the delay to restart heparin after surgery and the presence of an MV.

CONCLUSION

Post-operative use of heparin increases morbidity of pacemaker implantation. A different approach to management of these patients is possible.

Pocket Hematoma After Pacemaker or Implantable Cardioverter Defibrillator Surgery

STUDY OBJECTIVES

Pocket hematoma is a common complication after pacemaker or implantable cardioverter defibrillator (ICD) implantation. Thus, we investigated the influence of patient comorbidity, implantation strategy, operator experience, antiplatelet therapy, and anticoagulation therapy on hematoma rate.

DESIGN

Between 1990 and 2002, a total of 3,164 devices (pectoral pacemakers, 2,792; ICDs, 372) were implanted at our institution. Predictors of hematoma occurrence were determined prospectively and were analyzed by multivariate regression analysis. Operator experience was graded by individual implantation number, as follows: low, < 50; medium, 50 to 100; and high, > 100.

RESULTS

The incidence of pocket hematoma was 4.9%, leading to prolonged hospitalization in 2.0% of all patients. Reoperation for pocket hematoma was required in 1.0% of patients. High-dose heparinization (hazard ratio [HR], 4.2), combined acetylsalicylic acid (ASA)/thienopyridine treatment after coronary stenting (HR, 5.2), and low operator experience (HR, 1.6) were independently predictive of hematoma development. Therapy with ASA alone did not increase the hematoma rate compared to patients who did receive antiplatelet or anticoagulation therapy (3.1% vs 2.5%, respectively; difference not significant). In patients with nonvalvular atrial fibrillation, postoperative high-dose heparinization substantially increased the hematoma rate (10.7% vs 2.9%, respectively; p < 0.001) without reducing the rate of arterial embolism within the first month after implantation (0.18% vs 0.21%, respectively; difference not significant). The infection rate (0.28% within 3 months after implantation) was not influenced by the presence of the pocket hematoma.

CONCLUSIONS

The use of high-dose heparinization and combined ASA/thienopyridine treatment are highly predictive for the occurrence of intraoperative bleeding and pocket hematoma in patients who have undergone pacemaker and ICD surgery. We propose recommendations for the management of antiplatelet and anticoagulation therapy in patients undergoing these interventions.

Pacemaker and Implantable Cardioverter Defibrillator Implantation Without Reversal of Warfarin Therapy

The study evaluated all patients undergoing permanent pacemaker and ICD implantation over a 4-year period to determine if anticoagulated patients required normalization of coagulation factors in the periprocedural period. The study included 1,025 (597 men, 428 women, age 24-100 years, mean 72 years) consecutive patients who underwent device implantation using mostly a percutaneous subclavian approach. The procedures were performed without reversal of anticoagulation in 470 patients with INRs >or= 1.5 at the time of the procedure (mean INR 2.6 +/- 1.0, range 1.5-7.5). The complication rate in the anticoagulated group was similar to those in patients with a normal INR. Routine normalization of coagulation factors prior to pacemaker/ICD placement may not be necessary.

Elective coronary angiography and percutaneous coronary intervention during uninterrupted warfarin therapy

The management of patients anticoagulated with warfarin and referred for coronary angiography presents a substantial challenge to the physician who must minimize risks of periprocedural hemorrhage and thromboembolism. The aim of this study was to evaluate the feasibility and safety of performing diagnostic coronary angiography and percutaneous coronary intervention during uninterrupted warfarin therapy. Patients treated with warfarin were prospectively identified and enrolled in the study. Nineteen diagnostic cardiac catheterizations and six percutaneous coronary interventions were performed in 23 patients. The mean international normalized ratio was 2.4 +/- 0.5 (range, 1.8-3.5). Hemostasis was achieved with AngioSeal following 21 procedures and with Perclose following 4 procedures. No patient experienced a predefined endpoint. Specifically, no patient experienced procedure-related myocardial infarction, major or minor bleeding. We conclude that cardiac catheterization and percutaneous coronary intervention may be considered in the setting of uninterrupted warfarin therapy.

Implantation of pacemakers and implantable cardioverter defibrillators in orally anticoagulated patients

The safety of pacemaker and defibrillator implantations in orally anticoagulated patients using standard techniques has not been thoroughly evaluated. This article describes a prospectively collected experience in such patients. Patients presenting for device implantation who were treated with warfarin were allowed to continue therapy provided that the INR was < 3.5. Implantations involved cannulation of the left axillary vein. Except for defibrillator leads, 7 Fr introducers were used, and all were leads actively fixated. The study included 47 patients who underwent implantation of permanent pacemakers (n = 39), defibrillators (n = 5), or biventricular pacemakers (n = 3). The mean INR was 2.3. The primary indication for anticoagulation was a mechanical cardiac prosthesis in 11 (24%) patients. Atrial fibrillation was present in 33 patients. There were no instances of major bleeding or hematomas requiring evacuation. One patient had a small soft hematoma, which resolved spontaneously. At 6 weeks, all patients had well-healed scars with satisfactory pacing and sensing thresholds. In experienced centers, patients requiring treatment with warfarin may undergo implantation of pacemakers or defibrillators with minimal risk despite continuation of anticoagulation.

Implantable cardioverter defibrillators in heart failure

Implantable cardioverter defibrillators provide effective and reliable treatment of spontaneous VT and VF. These devices can be expected to decrease the risk for arrhythmic death in patients with heart failure but do not improve overall survival when death from severe pump dysfunction is imminent. Appropriate patient selection is a major aspect of arrhythmia management. Future devices will incorporate features that have the potential to reduce atrial arrhythmias, improve ventricular function, monitor hemodynamics, and prevent sudden arrhythmic death.