Multicenter investigation of the incidence of inferior vena cava filter fracture.

PURPOSE: Inferior vena cava filter fracture (FF) may cause life-threatening complications, including cardiac tamponade, although the actual prevalence remains unclear. Therefore, we investigated the incidence of FF. MATERIALS AND METHODS: Data on fracture incidence with filter brands, filter positions [suprarenal (SR) vs. infrarenal (IR)], and follow-up durations were collected from the databases of eight hospitals. RESULTS: Of 532 patients, Günther Tulip (GT), Trap/OptEase (TE/OE), ALN and VenaTech (VT) were implanted in 345, 147, 38 and 2 patients, respectively. Of these, filter retrieval was attempted in 110 (21.7%) patients and was successful in 106 (96.4%). Of the remaining 426 patients, FFs were observed in two (0.7%) of 270 GT filters and 19 (14.1%) of 135 TE/OE filters. Fragment embolization occurred in one patient with a GT filter (50.0%) and three with a TE/OE filter (15.8%) with a total follow-up interval of 718.0 ± 1019.4 days. FF occurred more frequently in TE/OE than in GT filters (p < 0.001). Kaplan-Meier estimates showed significantly higher fracture-free rates for GT than TE/OE (p < 0.001) and IR-TE/OE than SR-TE/OE (p < 0.05). CONCLUSIONS: TE/OE filters are not suitable for permanent implantation due to the relatively early and high fracture rates.

Sudden cardiac arrest recorded during Holter monitoring: prevalence, antecedent electrical events, and outcomes.

BACKGROUND: Causative arrhythmias of sudden cardiac arrest (SCA) are changing in this age of improved coronary care. OBJECTIVE: The purpose of this study was to examine the frequency of terminal arrhythmias and the electrical events prior to SCA. METHODS: We analyzed 24-hour Holter recordings of 132 patients enrolled from 41 institutions who either died (n = 88) or had an aborted death (n = 44). The Holter recordings were obtained for diagnosing and evaluating diseases and arrhythmias in those without any episodes suggestive of SCA. RESULTS: In 97 patients (73%), SCA was associated with ventricular tachyarrhythmias and in 35 (27%) with bradyarrhythmias. The bradyarrhythmia-related SCA patients were older than those with a tachyarrhythmia-related SCA (70 ± 13 years vs. 58 ± 19 years, P < .001). The most common arrhythmia for a tachyarrhythmia-related SCA was ventricular tachycardia degenerating to ventricular fibrillation (45%). The bradyarrhythmia-related SCA was caused by asystole (74%) or AV block (26%). Spontaneous conversion was observed in 37 patients (38%) with ventricular tachyarrhythmias. Of those, 62% of the patients experienced symptoms including syncope, chest pain, or convulsion. Multivariate logistic analysis revealed that independent predictors of mortality for tachyarrhythmia-related SCAs were advanced age (odds ratio 1.04, 95% confidence interval 1.02-1.08) and ST elevation within the hour before SCA (odds ratio 3.54, 95% confidence interval 1.07-13.5). In contrast, the presence of preceding torsades de pointes was associated with spontaneous conversion (odds ratio 0.20, 95% confidence interval 0.05-0.66). CONCLUSION: The most frequent cause of SCA remains ventricular tachyarrhythmias. Advanced age and ST elevation before SCA are risk factors for mortality in tachyarrhythmia-related SCAs.

Acute pulmonary embolism after an earthquake in Japan.

There have been no reports on acute pulmonary embolism (APE) after earthquakes. Our aim was to clarify the actual the occurrence of APE following the 2004 Mid Niigata Prefecture earthquake in Japan, and to assess the risk factors for APE after the event. We sent questionnaires to 122 hospitals in the Niigata Prefecture after the earthquake. Cities, towns, and villages in the prefecture were classified into two areas (high evacuee rate area, and low evacuee rate area) due to the mean ratio of evacuees to the overall population during 1 week immediately after the earthquake. A rate of 5% and higher was encountered for the high evacuee rate area and a rate of < 5% was encountered for the low evacuee rate area. Ten out-of-hospital cases of APE (seven in the high evacuee rate area and three in the low evacuee rate area) were diagnosed within the first month after the earthquake. The relative risk of APE was high in the high evacuee rate area (13.09; P = 0.0002) and also higher in women (8.55; P = 0.04). All patients in the high evacuee rate area had stayed in their automobiles for long periods of time, but none had done so in the low evacuee rate area ( P = 0.008).

Diagnostic and therapeutic strategy for acute pulmonary thromboembolism.

BACKGROUND: The diagnostic and therapeutic strategy for acute pulmonary thromboembolism (APTE) was published by the Japanese Circulation Society. But in Japan, there has been no report on how to improve the pre-test probability in APTE-suspected cases, to determine a practically available diagnostic strategy, nor has been a report that compares diagnostic methods and therapies for APTE by decision analysis. METHODS AND RESULTS: APTE was found in 66.7% before using diagnostic imaging techniques. Compared with the absence of APTE, prolonged immobilization, cancer, tachycardia, unilateral leg swelling and inverted T-wave in V(1-3) were found more often in the presence of APTE. The rate of obtaining the result on the day of ordering the examination test was 100% with arterial blood gas analysis, trans-thoracic echocardiography and computed tomography (CT), 78.2% in D-dimer, 85.5% in pulmonary angiography, and 54.5% in perfusion lung scan. Decision analysis showed that the highest expected utility was anticoagulant over 0.51 in pre-test probability, with CT between 0.13 and 0.51. CONCLUSIONS: The pre-test probability of APTE has already been high before using specific diagnostic imaging techniques in Japan. Our results showed that the diagnostic strategy for APTE made by the Japanese Circulation Society was available in most hospitals in Japan.

Risk factors of acute pulmonary thromboembolism in Japanese patients hospitalized for medical illness: results of a multicenter registry in the Japanese society of pulmonary embolism research.

BACKGROUND: Although the prophylaxis of acute pulmonary thromboembolism (APTE) in hospitalized patients has been improving in Japan, there is no report concerning APTE of Japanese medical patients. Therefore, the present study was designed to investigate the characteristics of APTE in Japanese patients hospitalized for medical illness, through a retrospective study. METHODS: In a total of 1,438 registry patients with pulmonary thromboembolism for recent 10 years, 1,027 patients with APTE were analyzed with respect to underlying diseases or predisposing factors, and clinical course. RESULTS: A hundred thirty three patients hospitalized for medical illness developed APTE, among 433 in-hospital APTE patients. The prevalence of APTE in women was more than in men. The mean age of the patients at diagnosis was 61 +/- 17 years. Main risk factors were a prolonged immobilization, stroke, cancer, indwelling central venous catheter. Fifty-four patients had 3 or more risk factors. In-hospital mortality rate was 23%. CONCLUSIONS: Japanese patients in this registry had almost the same findings as in western patients, except for some points that had the possibility of demonstrating a difference between westerners and Japanese in the development of APTE. Our results will be available for establishing the prevention of APTE in medical patients in Japan.

Clinical characteristics, diagnosis and management of patients with pulmonary thromboembolism who are not diagnosed in the acute phase and not classified as chronic thromboembolic pulmonary hypertension.

BACKGROUND: There have been many cases of pulmonary thromboembolism (PTE) that were not diagnosed in the acute phase and not classified as chronic thromboembolic pulmonary hypertension (CTEPH). The aim of the present study was clarify the clinical characteristics of chronic PTE. METHODS AND RESULTS: The study subjects were 601 patients (chronic PTE = 92, acute PTE = 456, CTEPH = 53) who were clinically diagnosed before their death. Dyspnea and chest pain, which are frequently found in acute PTE, were found less frequently in chronic PTE. The diagnosis of chronic PTE is often delayed in cases of mild to moderate severity with atypical onset. Chronic heart failure and chronic respiratory failure were most frequent in chronic PTE, and cerebrovascular disease was present in approximately 15% of the cases of chronic PTE. Pulmonary angiography and ventilation lung scan were used least frequently in acute PTE. Heparin and thrombolysis were used most frequently in acute PTE. CONCLUSIONS: Besides the atypical onset and reduced severity, the presence of preexisting diseases may be one of the reasons why the diagnosis for chronic PTE is delayed. The diagnostic and management techniques differ according to the type of PTE.

Effectiveness and safety of the thrombolytic therapy for acute pulmonary thromboembolism: results of a multicenter registry in the Japanese Society of Pulmonary Embolism Research.

OBJECTIVE: To assess the effectiveness and safety of thrombolytic treatment for acute pulmonary thromboembolism (APTE), especially in the hemodynamically stable patients with right ventricular afterload stress. METHODS AND RESULTS: In a total of 221 patients with APTE, the association between thrombolytic treatment and the clinical outcomes were investigated. Thrombolysis was given to 121 patients (Thrombolytic Group), and the remaining 100 patients were treated with anticoagulation alone (Anticoagulation Group). In both patients with prolonged shock and patients who were hemodynamically stable without right ventricular afterload stress, the rate of death and recurrence of APTE in Anticoagulation Group were similar to those in Thrombolytic Group. In patients with right ventricular afterload stress, better outcomes were observed in Thrombolytic Group than in Anticoagulation Group, although the difference did not reach statistical significance. There was no significant difference in the rate of major bleeding episode between these two groups. CONCLUSION: Our results suggested that performing thrombolytic treatment in APTE patients with right ventricular afterload stress should be considered even in Japan.

Inferior vena cava filter is a new additional therapeutic option to reduce mortality from acute pulmonary embolism.

BACKGROUND: There are few reports that examine the current imaging and management techniques according to the severity of acute pulmonary embolism (APE) or that clarify whether the management strategy ameliorated the mortality from APE. METHODS AND RESULTS: The study group were 456 patients with APE who were clinically diagnosed before their death. The severity at diagnosis, and the imaging and management techniques were analyzed. Mortality from APE was 0.8% in patients without shock nor right ventricular overload, 2.7% in patients with right ventricular overload without shock, 15.6% in patients with shock, and 52.4% in patients with cardiopulmonary arrest (p<0.0001). In the more severe cases, pulmonary angiography and trans-thoracic echocardiography were used more frequently, whereas both ventilation and perfusion lung scans were used less frequently. Computed tomography was used widely, regardless of the severity. Thrombolytic therapy and catheter therapy were used more frequently in the more severe cases, but an inferior vena cava filter was the only management strategy that reduced the mortality from APE. CONCLUSIONS: The severity of APE at diagnosis affected the selection of both the diagnostic techniques and the type of management. Implantation of inferior vena cava filters reduced the mortality from APE.

[Acute pulmonary thromboembolism--prologue].

For a long time, the studies of acute pulmonary thromboembolism in Japan have been focused on its early diagnosis and the rescue of the patients. However, the recent trends in the trials in the courts or the headlines in the newspapers have indicated that the major public interests are directed to its primary prophylaxis. Thus, the guidelines for the prophylactic strategy of acute pulmonary thromboembolism are needed today. It would be important to know (1) to what extent the thrombotic tendency should be examined, (2) how the patients with the risk could be identified, (3) which prophylactic interventions should be selected, and finally (4) what are the expected cost-benefit effects. An emphasis should be put on that the researches to derive quantitative estimates of the risks of thromboembolism and the studies of the efficacy of each of the prophylactic interventions in Japanese patients would provide the basis of such guidelines.

Recent developments in diagnostic imaging techniques and management for acute pulmonary embolism: multicenter registry by the Japanese Society of Pulmonary Embolism Research.

OBJECTIVE: There are many reports on the diagnosis and management of acute pulmonary embolism (APE), but there have been no investigations concerning the actual conditions in which recent developments in diagnostic imaging techniques and therapies have been applied in clinical practice. The present study was designed to investigate the changes in diagnostic imaging techniques and therapies for APE. METHODS AND PATIENTS: Three hundred and nine APE patients diagnosed during January 1994-October 1997 (Group 1) were compared with 257 APE patients diagnosed during November 1997-October 2000 (Group 2) in terms of the diagnostic imaging techniques and therapies for APE. RESULTS: Compared with Group 1, pulmonary angiography and contrast-enhanced computed tomography were more frequently performed for diagnosis in Group 2 [45.3% vs 56.8% (p = 0.0069) and 13.9% vs 57.6% (p < 0.0001), respectively]. Heparin and vena cava filter were used more often in Group 2 [74.4% vs 82.1% (p = 0.033) and 18.4% vs 33.9% (p < 0.0001), respectively]. The frequency of thrombolytic therapy was unchanged between the two groups. Warfarin use in discharged patients increased from 71.9% to 83.8% (p = 0.0022). However, the examination rates for deep vein thrombosis (DVT) were low (60.8% in Group 1 and 65.4% in Group 2, p = 0.29) and unchanged using any imaging techniques. CONCLUSION: The diagnostic imaging techniques for APE increased in variety and the management has improved, while the diagnosis for DVT remains unchanged.

Incidence and clinical characteristics of chronic pulmonary thromboembolism in Japan compared with acute pulmonary thromboembolism: results of a multicenter registry of the Japanese Society of Pulmonary Embolism Research.

The incidence of acute pulmonary thromboembolism (APTE) in Japan is quoted as being extremely low compared with the United States, and the incidence and clinical characteristics of chronic pulmonary thromboembolism (CPTE) in Japan is unknown, so this study investigated these aspects of CPTE in 309 patients with APTE and 68 patients with CPTE. The ratio of the incidence of CPTE to APTE was 0.22 and there was no significant difference in age or sex between the APTE and CPTE patients. All of the predisposing factors for pulmonary thromboembolism, except for thrombophilia, were more frequently seen in the patients with APTE. There are some differences in the incidence and clinical characteristics of CPTE compared with APTE between Japanese and American patients in Japan, suggesting that the pathogenesis of CPTE in Japan may differ from that in the USA.