Pulmonary embolism is an important cause of death in young adults.

BACKGROUND: Population-based analysis shows that deaths from pulmonary embolism (PE) are increasing in the older age groups, but it is unclear to what degree PE contributes to death in different ages and gender. METHODS AND RESULTS: Potential contribution factors for all PE and for critical PE (in which PE was the primary cause of death or the main diagnosis) were examined in 396,982 autopsy cases. For all PE, odds ratio (OR) in males was 0.61 (95% confidence interval (CI) 0.59-0.64, p<0.0001), compared with that in females. ORs were 1.10 (95% CI 1.05-1.14, p<0.0001) in 1991-1994 and 1.19 (95% CI 1.14-1.25, p<0.0001) in 1995-1998, compared with those in 1987-1990. ORs for ages 0-9 and 40+ were significantly low compared with that for ages 20-39. For critical PE, similar results were obtained. Pregnancy and/or delivery were found in 38.5% in cases of critical PE in females aged 20-39. CONCLUSION: Compared with other age groups, PE contributed more to deaths in those aged 20-39 years. In recent years, deaths from PE have been slightly but significantly increasing. The incidence of clinically diagnosed critical PE also has been increasing.

Unusual pulmonary embolism: septic pulmonary embolism and amniotic fluid embolism.

BACKGROUND: Septic and amniotic fluid emboli are rare sources of pulmonary embolism (PE), so the present study sought to elucidate the background of these cases. METHODS AND RESULTS: A total of 11,367 PE cases were identified from 396,982 postmortem examinations. The incidence of septic PE was 247 (2.2%) of the total. The origin of infection was found in 85.6% of the cases. Fungal embolus was detected more often than bacterial embolus. The most frequently detected fungus was aspergillus (20.8%). The primary disease associated with fungal embolus was leukemia (43.2%). The incidence of PE cases associated with pregnancy and/or delivery was 89 (0.8%) of the total PE cases. Among them, amniotic fluid embolism was found in 33 (73.3%) of 45 PE cases with vaginal delivery, and in 7 (21.2%) of 33 PE cases with cesarean delivery (p<0.0001). CONCLUSION: Fungal embolus was more frequent than bacterial embolus, and leukemia was most frequent as the primary disease in cases of fungal embolus. The main cause of PE in cesarean section cases was thrombotic embolism, and the main cause in vaginal delivery cases was amniotic fluid embolism.

Cancer and pulmonary embolism: thrombotic embolism, tumor embolism, and tumor invasion into a large vein.

BACKGROUND: The specific incidence of thrombotic pulmonary embolism (PE), tumor PE and tumor invasion into large veins according to tumor type and tumor site remains unclear. METHODS AND RESULTS: A total of 65,181 cancer patients were identified from 98,736 postmortem examinations. Thrombotic PE occurred in 2.32% of all cancer patients and comprised 88.6% of the total number of all PE events. The incidence of thrombotic PE was high in those with adenocarcinoma, leukemia and large cell carcinoma, and was low in those with hepatic cell carcinoma. The incidence of PE was high when tumor was present in hematogenous tissue, lungs, ovaries, pancreas and the biliary system, and was low when tumor was present in the liver. The incidence of tumor PE was high with large cell carcinoma, hepatic cell carcinoma and adenocarcinoma, and was also high when tumor was present in the lungs, ovaries, kidneys and liver. There was a significant correlation between the incidence of tumor PE and the incidence of tumor invasion into large veins. CONCLUSION: The incidence of thrombotic PE, tumor PE and tumor invasion into large veins varies significantly according to tumor histopathology and tumor site.

Portopulmonary hypertension: hemodynamics, pulmonary angiography, and configuration of the heart.

BACKGROUND: The goal of the present study was to examine the cardiac configuration and pulmonary vascular changes in patients with portopulmonary hypertension (PPHTN) and compare them with those of idiopathic pulmonary arterial hypertension (IPAH). METHODS AND RESULTS: The subjects were 10 patients with PPHTN and 18 with IPAH. In PPHTN, the increases in the right ventricular end-diastolic volume index (89+/-19 vs 128+/-50 ml/m2; p=0.04), right end-systolic volume index (50+/-19 vs 95+/-47 ml/m 2; p=0.02) and right ventricular mass index (47+/-18 g/m2 vs 79+/-31; p=0.04) were low compared with IPAH. The decrease in the right ventricular ejection fraction was also low in PPHTN (45+/-10 vs 28+/-13%; p=0.01). The degree of sparse arborization and abrupt narrowing on wedged pulmonary angiography was moderate in PPHTN compared with IPAH. In PPHTN, the proximal pulmonary arteries were dilated near the segmental arteries, which were narrow in IPAH. CONCLUSION: Changes in the configuration of the heart were moderate in PPHTN compared with those in IPAH. The degree of sparse arborization and abrupt narrowing were also moderate in PPHTN.

Efficacy of acute inhalation of nitric oxide in patients with primary pulmonary hypertension using chronic use of continuous epoprostenol infusion.

BACKGROUND: There have only been a few reports published on combination therapy for patients with primary pulmonary hypertension (PPH). METHODS AND RESULTS: Fifteen patients with PPH (4 men and 11 women, 34.5+/-12.1 years old) had received chronic administration of epoprostenol and the additive effects of inhaled nitric oxide (NO) and the hemodynamic changes were evaluated. In addition, the difference in the effect of acute NO loading before and after the epoprostenol therapy was compared in 6 of these patients. Under chronic use of epoprostenol, mean pulmonary arterial pressure, mean right atrial pressure and pulmonary vascular resistance were decreased with acute inhalation of NO. However, cardiac output, mean aortic pressure and systemic vascular resistance were unchanged. As a result, the pulmonary to systemic vascular resistance ratio was reduced. Moreover, after chronic use of epoprostenol, the change (delta) in cardiac output with NO inhalation was increased and the NO-induced decrease in pulmonary vascular resistance was augmented compared to those before the induction. CONCLUSION: Nitric oxide inhalation further improved the hemodynamics when combined with chronic use of epoprostenol in PPH patients. These results suggest the possibility that combination therapies can be used in the treatment for PPH patients.

Incidence and characteristics of pulmonary thromboembolism in Japan 2000.

OBJECTIVE: The incidence of pulmonary thromboembolism (PTE) is much lower in Japan than in the United States. The number of deaths from PTE, however, has gradually increased. The present study was designed to investigate the incidence and characteristics of PTE in Japan. METHODS AND MATERIALS: We sent 5,582 questionnaires to inquire about the number of new cases of PTE between August 1, 2000 and September 30, 2000. RESULTS: We received 1,702 replies and 205 new cases were registered. The number of new cases per year was 4,022 (95% confidence interval: 3,704-4,305) and the incidence was 32 (95% confidence interval: 29.2-33.9) patients per 1,000,000 people per year. Main risk factors were immobilization, surgery, trauma, and malignancy. The mortality within a month and 6 months was 16% and 20%, respectively. Half of the deaths within a month occurred on the diagnosis day. CONCLUSION: The results showed that the incidence of PTE in Japan 2000 tended to increase compared with that in 1996, but it was still much lower than that in the United States.

Greater impairment of right ventricular systolic function in patients with anterior myocardial infarction because of the extent of proximal lesions.

The present study examined the influence of the extent of the ischemic area on right ventricular (RV) systolic function and the relation between the RV global and regional systolic function in patients with anteroseptal myocardial infarction (MI). Biplane right ventriculography was performed in 15 subjects as the control group, and 46 patients with anteroseptal MI as the MI group. Three dimensions of the RV (the long axis dimension [LA], the anterior-posterior dimension [AP] and the septum-free wall dimension [SF]) were examined to assess regional function The MI group had a larger right ventricular end-systolic volume index and lower right ventricular ejection fraction than the control group. The more proximal the coronary lesion, the lower was the ejection fraction of the RV in the MI group. The MI group had lower percent shortening (% shortening) of the SF than the control group, but there were no significant change in the % shortening of AP and LA between the groups. The results suggest that the degree of impairment of RV systolic function depends on the extent of the infarcted area, and that the impairment is mainly from a reduction in the %shortening of the SF.

Effects and problems of continuous infusion of epoprostenol for patients with primary pulmonary hypertension.

OBJECTIVE: We examined the usefulness and the problems of epoprostenol (Epo) therapy in adult Japanese with primary pulmonary hypertension (PPH). SUBJECTS AND METHODS: In eleven cases with PPH, both acute and chronic effects, and clinical effects of Epo were assessed. RESULTS: In the acute challenge test (n = 6), Epo reduced both systemic and pulmonary vascular resistance and increased the cardiac output, but did not change the ratio of pulmonary to systemic vascular resistance, while the systemic and pulmonary blood pressure also did not change. In the chronic study (n = 9), Epo decreased the pulmonary blood pressure without changes in systemic blood pressure, and increased the cardiac output. Both systemic and pulmonary vascular resistance decreased with a decrease in the ratio of the pulmonary to systemic vascular resistance. The level of brain natriuretic peptide and atrial natriuretic peptide, NYHA functional class and 6-minute walking distance were improved by Epo therapy. In spite of Epo therapy, two patients did not improve and died. Another patient improved in terms of symptoms but then died suddenly from massive lung bleeding. Two patients who improved physically could not be discharged because of psychiatric problems. One patient underwent lung transplantation. Five out-patients have been continuing Epo therapy. CONCLUSION: We demonstrated that the chronic effect of Epo treatment is sufficient even at the dose used in our hospital. However, it was shown that there was resistance to this therapy in some of the cases and that we should pay attention to the severe adverse effects of Epo.

Hemodynamic effects of inhaled nitric oxide using pulse delivery and continuous delivery systems in pulmonary hypertension.

OBJECTIVE: Inhaled nitric oxide (NO) has been used for pulmonary vasodilation therapy in patients with pulmonary hypertension. Inhaled NO for awake and ambulatory patients, however, is unusual because it requires intubation or a tightly fitting facemask, and a large-scale delivery system for the safe management of toxic nitrogen oxides. We undertook this study to investigate the possibility of using inhaled NO therapy for awake and ambulatory patients with pulmonary hypertension. METHODS: Patients with pulmonary hypertension underwent cardiac catheterization and hemodynamic variables were measured at the baseline, after inhaled NO using our pulse delivery system, which involved a nasal cannula and a pulse device, and after inhaled NO using a continuous delivery system. PATIENTS OR MATERIALS: We studied seventeen patients with precapillary pulmonary hypertension (4 men and 13 women; age, 41+/-3, ranging from 19 to 61). RESULTS: Cardiac output was increased significantly by each system. Pulmonary vascular resistance was decreased significantly by each system. There was no significant change in mean pulmonary artery pressure, mean systemic artery pressure, or systemic vascular resistance. The concentrations of NO and nitrogen dioxide (NO2) in the expiratory gas using the pulse delivery system were 0.0 ppm as long as the pulse device was synchronized with the patient's respiratory cycle. CONCLUSION: Inhaled NO using our pulse delivery system changed the hemodynamic variables similarly to those when using the continuous delivery system. The concentrations of NO and NO2 in the expiratory gas using the pulse delivery system were within safe limits.