Predictors of pocket hematoma in patients on antithrombotic therapy undergoing cardiac rhythm device implantation: insights from the FinPAC trial.

BACKGROUND: The FinPAC trial showed that the strategy of uninterrupted oral anticoagulation (OAC) was non-inferior to interrupted OAC for the primary outcome of bleeding and thromboembolic complications in patients undergoing cardiac rhythm management device (CRMD) implantation. METHODS: We conducted a post hoc analysis of the FinPAC data to explore the incidence and predictors of significant (> 100 cm(2)) pocket hematoma after CRMD implantation among the study population (n = 447). A total of 213 patients were on OAC, 128 were on aspirin, and 106 on no antithrombotic therapy. RESULTS: The incidence of significant pocket hematoma during hospital stay was significantly higher among patients using OAC (5.6%) and aspirin (5.5%) than in those with no antithrombotic medications (0.9%), but only one patient (0.8%) in the aspirin group needed revision of hematoma. Two patients (0.9%) in the OAC group and one (0.8%) in the aspirin group needed blood products. In multivariable regression analysis, no pre- procedural features predicted the significant hematoma in any of the groups. CONCLUSIONS: Clinically significant pocket hematoma is a rare complication after CRMD implantation in patients with ongoing therapeutic OAC. The incidence of significant pocket hematoma formation is similar in patients using OAC and those using aspirin.

Safety of pacemaker and implantable cardioverter-defibrillator implantation during uninterrupted warfarin treatment--the FinPAC study.

BACKGROUND: Periprocedural management of oral anticoagulation (OAC) in patients undergoing cardiac rhythm management (CRM) device implantation is controversial. Prior studies demonstrate that uninterrupted OAC may be safe, but limited data from randomized trials exist. METHODS: We conducted a multicenter, randomized trial to evaluate the safety of uninterrupted OAC during CRM device implantation. Patients on long-term warfarin (N=213) treatment with contemporary indication for CRM device implantation were randomized to uninterrupted versus interrupted (2 days) OAC therapy. The primary outcome included major bleeding events necessitating additional intervention and thromboembolic events during 4 weeks follow-up. RESULTS: The randomized groups were well matched in terms of bleeding and thromboembolic risk. Only one (1%) patient in the uninterrupted OAC group (N=106) needed blood transfusion due to rupture of proximal cephalic vein. Large hematomas were detected in 6% of patients in both groups, but there was no need for pocket revision in either group. Any pocket hematoma was observed in 35 patients (33%) in the uninterrupted OAC group and in 43 patients (40%) with interrupted OAC and uninterrupted OAC strategy was non-inferior to interrupted OAC (HR 0.86, 95%, p=0.001 for non-inferiority). One patient with interrupted OAC had stroke 3 days after the procedure. Hospital stay was comparable in all patient groups. CONCLUSION: Our randomized study demonstrates that CRM devices can be safely implanted without discontinuation of warfarin treatment.

Clinical and laboratory risk factors of thrombotic complications after pacemaker implantation: a prospective study.

AIMS: Venous lesions, including obstruction and thromboembolism (VTE), are not uncommon after pacemaker implantation. The purpose of this prospective study was to assess the role of various patient and procedure-related risk factors in the development of these complications. METHODS AND RESULTS: A prospective venography-based study of 150 consecutive pacemaker implantations with a 6-month follow-up was conducted. Current case-control study included all cases (n = 47) with a new venous lesion, and their matched controls. Several surgical and technical factors, i.e. lead burden, choice of venous access, operator experience and procedure duration, as well as patient-related classic risk factors of VTE were assessed. Plasma markers of coagulation and endothelial activation [prothrombin fragment 1 + 2 (F1 + 2), D-dimer (DD), von Willebrand factor (vWF), thrombomodulin (Tm)] were used to evaluate the extent of acute surgical trauma. All cases with venous lesions were also screened for thrombophilia. None of the procedure-related variables were predictive of VTE. Mean levels of vWF, F1 + 2 and DD increased significantly (P < 0.001) and equally in both cases and controls. No single clinical factor predicted venous lesions, but significant (P < 0.05) clustering of classic clinical VTE risk factors was seen among the cases. Thrombophilia was overrepresented in patients with symptomatic pulmonary embolism (2/5, 40%). CONCLUSION: Pacemaker implantation induces a transient hypercoagulable state, but its degree does not predict subsequent venous thromboembolism, and neither did the grade of endothelial damage as reflected by plasma markers. The aetiology of these lesions seems to be multifactorial, and clustering of classic thrombotic risk factors plays a role in the pathogenesis.

Progression of venous pathology after pacemaker and cardioverter-defibrillator implantation: A prospective serial venographic study.

BACKGROUND AND AIMS: Prospective data on development of venous obstruction after electrode implantation are limited. We performed a prospective study on 150 patients undergoing first pacemaker implantation. METHODS: Venographies at base-line and 6 months postimplantation in all patients, 50 patients included into a long-term follow-up of a mean of 2.4 years after implantation. RESULTS: At 6 months 14% had obstructions, but only 1 patient (0.7%) developed acute symptomatic upper extremity venous thrombosis. Pulmonary embolism (PE) was encountered in 5 (3.3%). After 6 months only 2 patients experienced pain in ipsilateral arm, but none had edema of arm, neck or head, or clinical PE. The 5 patients with total venous occlusion (TVO) at 6 months had no localized symptoms. Late venographic abnormalities developed in 5 (10%) patients: 4 TVOs and 1 stenosis. Two of the new lesions developed among 25 patients with normal 6-month venograms. Overall, TVO was detected in 9 of 150 patients. No factors emerged as independent predictors of total occlusion in multiple regression analysis. CONCLUSIONS: TVO is not uncommon after pacemaker implantation, and mostly occurs without any localizing symptoms. Most venous lesions seem to develop during the first months postimplantation, but late and unpredictable TVO may also occur.

Health risk assessment of indoor air pollution in Finnish ice arenas.

Poor indoor air quality and epidemic carbon monoxide (CO) and nitrogen dioxide (NO(2)) poisonings due to exhaust emissions from ice resurfacers have been continuously reported from enclosed ice arenas for over 30 years. The health risks in users of Finnish ice arenas were analysed in three ways: (1) evaluation of four cases of epidemic CO poisonings, (2) modelling the association between NO(2) exposure and respiratory symptoms among junior ice hockey players, and (3) estimation of the number of arena users at risk of breathing poor quality air due to non-compliance of ice arenas with recommended abatement measures. The common causes for the CO poisonings involving over 300 subjects were large emissions from propane-fuelled ice resurfacer, small arena volume, negligible ventilation, and very recent opening of the arena. Rhinitis (prevalence 18.3%) and cough (13.7%) during or after training or game were significantly associated with the estimated personal NO(2) exposure of young hockey players (n=793) to average concentrations ranging from 21 to 1176 microg/m(3) in their home arena. During a 6-year follow-up of an intensive information campaign the portion of electric resurfacers increased from 9% to 27%, and that of emission control technology on propane-fuelled resurfacers increased from 13% to 84%. The portion of inadequately ventilated arenas decreased from 34% to 25%. However, 48% of the investigated Finnish ice arenas (n=125) did not fully comply with the non-regulatory recommendations. Consequently, 20000 daily users of ice arenas were estimated to remain in 2001 at risk of breathing poor quality air. Modern small and inadequately ventilated ice arenas pose their users (mostly children and young adults) at risk of breathing poor quality air and suffering from acute adverse health effects. Governmental regulations are needed worldwide to ensure safe sports in enclosed ice arenas.

Venous obstruction after pacemaker implantation.

BACKGROUND: Central vein leads are known to predispose to venous obstruction. Although usually asymptomatic, obstruction may render electrode removal difficult. This study aimed at quantifying changes in venous calibers in a prospective fashion by intravenous contrast venography (ICV) before and after pacemaker (PM) or cardioverter-defibrillator implantation. METHODS: One hundred and fifty (mean age 67; 61% male) consecutive patients were enrolled, and followed for 6 months. A successful ICV was done at baseline prior to implantation and at 6-month follow-up in 136 (91%) patients. Minimum (D(min)) and maximum (D(max)) vessel diameters were obtained from both ICVs. A new stenosis was defined as a 50% diameter reduction in a venous segment when compared to baseline. We implanted a total of 230 electrodes: 47 (34.6%) single lead, 84 (61.8%) 2-lead, and 5 (3.7%) 3-lead systems. RESULTS: At baseline ICV, 10 patients (7%) were found to have venous anomalies, including 8 patients with obstructive lesions, 1 patient with a persistent left superior vena cava, and 1 patient with double axillary vein. At 6 months, a new obstructive venous lesion had developed in a total of 19 (14%) patients, none of whom exhibited any local symptoms. Of these patients 14 (10%) had a stenosis (mean D(min) 4.6 mm and diameter 38% of baseline), and 5 (3.6%) had a complete venous occlusion. In most cases the new stenosis developed in a location where the vessel was narrowest at baseline. Clinical predictors for the development of stenosis were atrial fibrillation at baseline and biventricular PM implantation. CONCLUSIONS: This is the first systematic study to quantify venous changes after PM or ICD implantation. Our study shows that venous anomalies rendering PM implantation difficult are not infrequent. The incidence of new venous obstruction was 14%. Atrial fibrillation and biventricular PM implantation were independent predictors of venous obstruction.

Transesophageal echocardiography in the diagnosis of thrombosis associated with permanent transvenous pacemaker electrodes.

OBJECTIVES: We sought to assess the value of transesophageal echocardiography (TEE) in the diagnosis of PM-lead-associated central venous thrombi. BACKGROUND: Venous thrombosis is not infrequent after pacemaker (PM) or implantable cardioverter-defibrillator (ICD) implantation. Previous incidence studies of thrombosis have been based on venography or Doppler ultrasound, but the role of TEE has not been systematically evaluated in this setting. METHODS: Study group comprised 66 consecutive patients (mean age 64 years, 67 % male) referred for implantation of their first PM or ICD and with a successful TEE, transthoracic echocardiography (TTE) and venography at 6 months after implantation. The total number of implanted leads was 110. During the 6 months of clinical follow-up, nuclear ventilation-perfusion scan or spiral computed tomography was performed when symptoms aroused a clinical suspicion of PE. RESULTS: TEE revealed a right atrium (RA) or lower superior vena cava (SVC) thrombus in 6 (9%) patients. These thrombi were not visualized by TTE or venography. Additionally, 12 (20%) patients were found to have venographic subclavian or innominate vein thrombi, but none of those could be diagnosed with TEE. Symptomatic pulmonary embolism (PE) was diagnosed in two and an asymptomatic PE in one individual and two of these occurred among the six patients with a thrombus in TEE. No clinical predictors for thrombosis were found. CONCLUSIONS: TEE is an excellent method to visualize electrodes within the RA and proximal SVC. Electrode-associated RA thrombi appear to be relatively common after PM implantation, and they may remain undetectable by venography or TTE. Although these thrombi are mostly asymptomatic, they can give rise to pulmonary embolism and should also be kept in mind in the differential diagnosis of endocarditis. TEE is the method of choice for the diagnosis of these lesions.