Stroke case fatality shows seasonal variation regardless of risk factor status in a Japanese population: 15-year results from the Takashima Stroke Registry.

BACKGROUND: Seasonal variation in fatality caused by stroke was examined using 15 years of data from a stroke registry of a Japanese population. METHODS: Data were obtained from the Takashima Stroke Registry, which covers approximately 55,000 residents in central Japan. There were 1,650 registered cases of first-ever stroke between 1988 and 2002. 7- and 28-day fatality rates and 95% confidence intervals were calculated for winter, spring, summer and autumn. After adjusting for gender, age at onset and risk factors, the hazard ratios for fatal strokes in winter, spring and autumn were calculated, with summer serving as the reference. RESULTS: For cerebral infarction, the highest 7- and 28-day fatality rates occurred during spring and winter, where they were more than double the rate during summer. The severest strokes were also more likely to occur during winter and spring. A high spring and winter hazard ratio for 28-day mortality was present in both lacunar and nonlacunar subtypes, in both genders and in subjects < 65 and > or = 65 years of age. No apparent seasonal pattern was observed for cerebral hemorrhage or subarachnoid hemorrhage. The spring and winter excess fatality persisted even after adjusting for age, gender and risk factors. CONCLUSION: Patients who suffer an ischemic stroke during winter or spring have a poorer prognosis. Further investigation is needed to determine the factors that explain this excess risk.

Incidence, admission and case-fatality of acute myocardial infarction: weekend versus weekday in a Japanese population: 16-year results from Takashima AMI Registry (1988-2003).

For acute myocardial infarction (AMI), "weekend" has been associated with higher incidence, admission, and fatality. But, very few studies in this regard are available in Japan. Day of the week variation in AMI was examined using an entire community covering 16-year AMI registration data from Japan. Data were obtained from the Takashima AMI Registry, which covers a stable population of approximately 55,000 in central Japan. There were 379 registered first ever AMI cases with 121 fatal events within 28 days of onset during 1988-2003. We divided the days into two groups: 'Weekend' (Saturday and Sunday) and 'Weekdays' (Monday to Friday). The incidence rate (per 100,000 person-year), admission rate (per 1,000 days) and 28-day case-fatality rates (per 100 events) as well as corresponding rate ratios were calculated with 95% confidence intervals. The distribution of the day of the week for onset, admission and fatality for all subjects was fairly random in our study population; incidence (chi (2) test, P = 0.8), admission (chi (2) test, P = 0.9) and case-fatality (chi (2) test, P = 0.8). The incidence, admission, and case-fatality rates were similar for the 2 day-groups. The incidence rate ratio 1.06 (95% CI: 0.9-1.3), admission ratio 1.03 (95% CI: 0.8-1.3), and case-fatality ratio 1.18 (95% CI: 0.7-1.9) showed no significant risk difference between weekend and weekday. After various adjustments, hazard ratio for weekend AMI in reference to weekday AMI was 1.07 (95% CI: 0.5-2.1). There were no obvious differences in occurrence, hospital admission and acute outcome for AMI patients in the weekday or weekend.

Seasonal pattern of incidence and case fatality of acute myocardial infarction in a Japanese population (from the Takashima AMI Registry, 1988 to 2003).

We examined the seasonal variations in the incidence and case fatality of acute myocardial infarction (AMI) in a geographically defined population using 16-year AMI registration data. It remains unclear whether the incident events of AMI display any seasonal variation. Documentation of such a pattern may foster investigation for understanding the potential mechanisms responsible for these effects and may provide novel avenues for prevention of AMI. Data were obtained from the Takashima AMI Registry, which covers an entire community of approximately 55,000 in central Japan. There were 335 definite cases of AMI during 1988 to 2003 (217 men, 118 women). Of these, there were 96 fatal cases (53 men, 43 women) within 28 days of onset. Incidence rates (per 100,000 person-years) and case fatality rates with 95% confidence intervals (CI) were calculated across seasons. Poisson regression analysis was used to calculate the incidence rate, and case fatality ratios adjusted for age and gender. The AMI incidence rate was higher in winter (44.9, 95% CI 35.9 to 53.9) and spring (44.1, 95% CI 35.3 to 52.9) than the other seasons. After adjustment for age and gender, AMI risk was 1.4 (95% CI 1.03 to 1.9) times higher in winter and was 1.4 (95% CI 1.01 to 1.9) times higher in spring than summer. The 28-day AMI case fatality rate was also higher in winter (34.4%, 95% CI 24.9 to 43.9) and spring (32.3%, 95% CI 22.9 to 41.7). Age- and gender-adjusted fatality risk was 2.4 (95% CI 1.2 to 4.9) times higher in winter and 2.3 (95% CI 1.1 to 4.6) times higher in spring than summer. In conclusion, higher AMI incidence and case fatality rates were observed in winter and spring in a Japanese population.

Case fatality of stroke and day of the week: is the weekend effect an artifact? Takashima stroke registry, Japan (1988-2003).

BACKGROUND AND PURPOSE: For stroke admissions, the 'weekend effect' has been associated with higher stroke fatality. However, it is unclear if stroke case fatality shows this pattern if the onset day is taken into account. Day of the week variation in stroke case fatality was examined using 16-year stroke registration data. DESIGN AND METHODS: Data were obtained from Takashima Stroke Registry in central Japan. There were 1,578 registered first-ever cerebral infarction and cerebral hemorrhage stroke cases during 1988-2003. We divided the days into 2 groups: 'weekend' and 'weekdays'. The 7-day and 28-day case fatality rates and 95% confidence intervals (95% CI) were calculated by gender, age and stroke subtype. RESULTS: For all strokes, the 7-day case fatality rate based on the hospital admission day was 9.5% (95% CI: 6.8-13.1) for weekend admissions and 7.3% (95% CI: 6.0-8.9) for weekday admissions. However, case fatality rates based on the onset day were 7.2% (95% CI: 5.1-10.0) for weekend onset and 8.0% (95% CI: 6.6-9.8) for weekday onset. The 28-day case fatality rate for the weekend admission group was 14.7% (95% CI: 11.3-18.8) and for the weekday admission group it was 10.1% (95% CI: 8.5-11.9). In contrast, the 28-day case fatality rate for the weekend onset group was 11.3% (95% CI: 8.6-14.7) and for the weekday onset group it was 11.0% (95% CI: 9.3-13.0). This phenomenon was observed mainly for cerebral infarction and to some extent for cerebral hemorrhage. CONCLUSION: Stroke fatality rates based on the day of admission were higher during the weekend than weekdays, although the difference did not reach statistical significance. However, this trend disappeared when the fatality rate was based on the day of onset.

QRS voltages are transiently increased at the superacute stage of experimental myocarditis.

BACKGROUND: There are few reports on the precise electrocardiographic characteristics of acute myocarditis. The present study was focused on QRS voltage changes at the superacute stage of murine myocarditis. METHODS: Serial electrocardiograms were recorded during the acute stage of viral myocarditis in mice, and then the cardiac pathology was examined. After recording baseline electrocardiograms, mice (n=235) were inoculated intraperitoneally with the encephalomyocarditis virus, resulting in severe myocarditis. Electrocardiograms were serially recorded until nine days after virus inoculation (superacute stage, days 3 to 6; acute stage, days 7 to 9). Changes in heart rate and QRS voltages were analyzed. RESULTS: Serial electrocardiograms revealed that heart rates began to increase after day 3, and that the sum of the QRS voltages increased on day 3 and then decreased on days 7 to 9. Trivial mononuclear cell infiltrations and interstitial edema were most frequently found in mice at the superacute stage. CONCLUSIONS: Transient increase of the QRS voltages at the superacute stage of myocarditis was demonstrated, which may be due to an increase in ventricular mass caused by interstitial edema at this stage.

Trend of increase in the incidence of acute myocardial infarction in a Japanese population: Takashima AMI Registry, 1990-2001.

The incidence and mortality of acute myocardial infarction (AMI) remain low in Japan despite major dietary changes and worsening cardiovascular risk factors, a situation that should have resulted in a substantial increase in AMI rates (Japanese paradox). The current trend in the incidence of AMI was examined for the period 1990-2001 by use of data from the Takashima AMI Registry covering a stable population of approximately 55,000 in central Japan. AMI incidence rates (per 100,000 person-years) and 95% confidence intervals were calculated for 1990-1992, 1993-1995, 1996-1998, and 1999-2001. The incidence trend was determined by calculating the average annual change in percentage across the years. There were 352 (men: n = 224; women: n = 128) registered first-ever AMI cases during 1990-2001. The age-adjusted incidence rate of all AMI showed a gradual increase from 39.9 (95% confidence interval (CI): 29.8, 50.0) in 1990-1992 to 62.6 (95% CI: 51.5, 73.7) in 1999-2001. In men, the age-adjusted incidence rate increased from 66.5 (95% CI: 46.4, 86.6) in 1990-1992 to 100.7 (95% CI: 78.6, 122.7) in 1999-2001. In women, fluctuation was observed after an initial steep increase. The average annual incidence increased by 7.6% (95% CI: 3.5, 11.7) among men and by 8.3% (95% CI: 1.02, 15.6) among women. To the best of the authors' knowledge, this is the first study to report an increasing trend of AMI in a Japanese population.

Reduction of infracardiac intestinal activity by a small amount of soda water in technetium-99m tetrofosmin myocardial perfusion scintigraphy with adenosine stress.

BACKGROUND: In technetium (Tc)-99m myocardial perfusion imaging (MPI), intestinal activity often interferes with the assessment of myocardial perfusion of the inferior wall. We examined whether a small amount of soda water prevents intestinal activity and improves image quality of the inferior wall in Tc-99m tetrofosmin MPI. METHODS AND RESULTS: Ninety-five patients referred for 1-day rest/stress Tc-99m tetrofosmin MPI were assigned to one of two groups automatically, according to the date when they underwent MPI: the soda water group (n = 63) ingested 100 mL soda water just before image acquisition after adenosine stress, and the control group (n = 32) underwent no intervention. The frequency of intestinal activity was assessed visually on planar images. The inferior myocardial wall and the abdominal activity adjacent to the myocardium were assessed quantitatively on three different planar images during stress, and the mean inferior wall-to-abdomen (I/A) count ratio was calculated. The frequency of intestinal activity was 69.8% in the soda water group, and 90.6% in the control group (P = .038). The I/A count ratio was significantly higher in the soda water group than in the control group (1.98 +/- 0.51 vs 1.50 +/- 0.35, respectively, P < .0001, +/- SD). CONCLUSIONS: The intake of 100 mL of soda water improves intestinal activity and improves the image quality of the inferior wall.

Higher stroke incidence in the spring season regardless of conventional risk factors: Takashima Stroke Registry, Japan, 1988-2001.

BACKGROUND AND PURPOSE: Seasonal variation in stroke incidence was examined using 14-year stroke registration data in a Japanese population. We also examined if this variation was modified by conventional stroke risk factors hypertension, diabetes mellitus, drinking, and smoking. METHODS: Data were obtained from the Takashima Stroke Registry, which covers a stable population of approximately 55,000 in Takashima County in central Japan. There were 1665 (men, 893; women, 772) registered first-ever stroke cases during 1988 to 2001. The average age of stroke onset for men and women patients was 69.4 and 74.2 years, respectively. Incidence rates (per 100 000 person-years) and 95% CI were calculated by gender, age, and stroke subtype for winter, spring, summer, and autumn. After stratifying patients by their risk factor history, the OR (with 95% CI) of having a stroke in autumn, winter, and spring were calculated, with summer serving as a reference. RESULTS: Among the seasons, stroke incidence per 100,000 person-years was highest in the spring (231.3; 95% CI, 211.1 to 251.5). Spring incidence was highest in both men (240.8; 95% CI, 211.5 to 270.2) and women (222.1; 95% CI, 194.4 to 249.9), and in subjects younger than 65 years (72.6; 95% CI, 60.0 to 85.3) and 65 years or older (875.9; 95% CI, 787.5 to 964.3). Among stroke subtypes, spring incidence was highest for cerebral infarction (154.7; 95% CI, 138.2 to 171.2) and cerebral hemorrhage (53.7; 95% CI, 44.0 to 63.4). The spring excess in stroke incidence was observed regardless of the presence or absence of the risk factor histories. CONCLUSIONS: Stroke incidence appears to be highest in the spring among a Japanese population regardless of conventional risk factor history. Factors that explain this excess need further investigation.

Registration and surveillance of acute myocardial infarction in Japan: monitoring an entire community by the Takashima AMI Registry: system and design.

BACKGROUND: The purpose of this registration is to follow incidence and case fatality trend of acute myocardial infarction (AMI) in Japan, using a whole community population disease registry that surveys the most up-to-date information. Since the 1970s, mortality from coronary heart disease has followed a declining trend in Japan, which has been attributed to a decrease in the incidence of AMI and some evidence suggests that incidence has leveled off during the past couple of decades. These reported decreasing or stable trends in AMI have been observed despite recent worsening of the cardiovascular risk factor situation in Japan (Japanese paradox). Therefore, monitoring the disease course of AMI is of immense importance. METHODS AND RESULTS: The Takashima AMI Registry established in 1988 covers a stable population of approximately 55,000 in Takashima County in central Japan. Registered patients included all Takashima County residents who have been diagnosed with AMI. The criteria of AMI are in accord with those of the World Health Organization's Monitoring of Trends and Determinants in Cardiovascular Disease (WHO-MONICA) project. CONCLUSION: Comprehensive disease registry data is especially appropriate for determining the incidence as well as the trend of diseases such as AMI. This registration study covering an entire community will enable researchers to follow trends in AMI incidence with a high degree of precision.

Relevance of inflammatory cell infiltrates for complete atrioventricular block in experimental murine myocarditis.

BACKGROUND: There are few systemic pathologic studies on myocarditis. This study aimed to clarify the pathologic characteristics of murine myocarditis. METHODS: We recorded serial electrocardiograms in experimental viral myocarditis in mice and then examined their cardiac pathology. After taking baseline electrocardiograms, we inoculated the mice intraperitoneally with the encephalomyocarditis virus. Electrocardiograms were serially recorded until 220 days after the virus inoculation. RESULTS: Serial electrocardiograms revealed ectopic beats, low voltage of the QRS complex, and the appearance of complete atrioventricular (AV) block. Corresponding myocardial lesions were found in the hearts of mice with these ectopic beats. Mononuclear cell infiltrations into the His bundle were most frequently found in mice with complete AV block. CONCLUSIONS: Inflammatory change with cellular infiltrations was the most common pathologic finding in mice with complete AV block. In clinical settings, anti-inflammatory therapy might be recommended for patients with myocarditis complicated with conduction disturbances.

Complete atrioventricular block in experimental murine myocarditis.

BACKGROUND: There were few reports on the pathological characteristics of the conduction system in myocarditis. This study was aimed to clarify the pathological characteristics of complete atrioventricular (AV) block in myocarditis. METHODS AND RESULTS: We studied serial electrocardiograms in experimental myocarditis in mice and also examined their cardiac pathology. After taking baseline electrocardiograms, mice were inoculated intraperitoneally with the encephalomyocarditis virus. Electrocardiograms were serially recorded until day 360. Serial electrocardiograms revealed the appearance of complete AV block. Myocardial lesions were found in the hearts of mice with these ectopic beats. Mononuclear cell infiltrations into the His bundle and necrotic lesions of the conduction system were found in 10.7% (18/168) of mice with complete AV block. However, 17.3% (29/168) of mice showed no evident pathological lesions except the edematous changes of AV node. CONCLUSIONS: The appearance of complete AV block in myocarditis may suggest not only significantly comparable pathological lesions of the conduction system but also the trivial edematous changes; in clinical settings, in the former case, permanent pacing therapy is necessary, and in the latter case, the disease may be transient and could be recovered from complete AV block. This study may shed light on the pathological characteristics of complete AV block in myocarditis.

[Tumor microembolism presenting as characteristic patterns of pulmonary perfusion on lung scanning: a case report].

A 55-year-old man presented with tumor microembolism manifesting as characteristic patterns of pulmonary perfusion on lung scanning. He had a 2-week history of dyspnea and general fatigue. Echocardiography demonstrated right ventricular enlargement. Computed tomography of the chest was normal. Lung perfusion imaging showed multiple subsegmental peripheral defects, which were characteristic of tumor embolism. Ultrasonography and computed tomography of the abdomen revealed multiple enlargement of the lymph nodes. Upper gastrointestinal panendoscopy showed gastric cancer. At 10 days after admission, he suffered cardiac arrest and died despite resuscitative efforts. Histological examination revealed pulmonary arterial obstruction with tumor cells, and poorly differentiated adenocarcinoma in the stomach and lymph nodes. This case emphasizes the need to include tumor microembolism in the differential diagnosis of dyspnea, even if there is no evidence of an underlying malignant tumor.

Anti-oxidant effects of coenzyme Q10 on experimental viral myocarditis in mice.

We studied the effects of coenzyme Q10 (CoQ10) on mice with acute myocarditis inoculated with the encephalomyocarditis (EMC) virus with the analysis of indices of effects of oxidative injury and DNA damage in the myocardium. The mice were treated as follows: CoQ10 group (n = 118); CoQ10 1.0 mg (0.1 mL) x 2/d (0.1 mg/g/d), control group (n = 128); sham-liquid 0.1 mL x 2/d. The mice were injected intraperitoneally 1 day before and daily for 12 days after EMC virus inoculation. The expression of thioredoxin, a marker of oxidative stress overload, as well as 8-hydroxy-2'-deoxyguanosine, an established marker of DNA damage, in the myocardium was investigated. The survival rate was significantly higher (P < 0.01) in the CoQ10 group (46.8%, 29/62) than in the control group (14.3%, 10/70). There were significant increases of CoQ9 and CoQ10 in the heart, which are the biologically active forms of CoQ in mice, and significant decrease of serum creatine kinase (CK)-MB in the CoQ10 group as compared with the control group. Histologic examination showed that the severity of myocarditis was less severe (P < 0.01) in the CoQ10 group than in the control group. In addition, the up-regulation of myocardial thioredoxin with DNA damage, which was induced by the inflammatory stimuli by the virus, was suppressed by the CoQ10 treatment, which may reflect the anti-oxidant effects of CoQ10 treatment. Thus, pretreatment with CoQ10 may reduce the severity of viral myocarditis in mice associated with decreasing oxidative stress in the condition.