Risk of dementia according to smoking cessation after newly diagnosed atrial fibrillation: a nationwide cohort study

Background

Incident atrial fibrillation (AF) is associated with an increased risk of dementia. There are limited data about the impact of smoking cessation after AF diagnosis on the risk of incident dementia.

Purpose

To evaluate the association between changes in smoking status after newly diagnosed AF and the risk of dementia.

Methods

Among patients with new-onset AF between 2010 and 2016, those who received a national health checkup exam within 2 years before and after the AF diagnosis were included. Patients who had prevalent dementia were excluded. Subjects were categorized into 4 groups according to the status of smoking before and after AF diagnosis: (1) never smoker; (2) ex-smoker; (3) quit-smoker after AF diagnosis; and (4) current smoker. The primary outcome was incident dementia during follow-up.

Results

A total of 126,252 patients were included (mean age 63, SD 12.0; men 62%; mean CHA2DS2-VASc 2.7). During a median 3 years of follow-up, dementia occurred in 5,925 patients (1.11 per 1000 person-years [1000PY]) (Alzheimer's dementia 1.5 per 1000 PY and vascular dementia 0.24 per 1000 PY, respectively). Never smokers, ex-smokers, quit-smokers, and current smokers were 52%, 27%, 7%, and 14% of the total study population, respectively. After multivariable adjustment, quit-smokers showed a higher risk of dementia than never smokers (hazard ratio [HR] 1.16, 95% confidence interval [CI] 1.03–1.32), but the risk was significantly decreased when compared to current smokers (HR 0.83, 95% CI 0.72–0.95). Alzheimer's dementia and vascular dementia showed consistent results as main (Figure).

Conclusion

All types of smoking were associated with a significantly higher risk of dementia in patients with new-onset AF. Smoking cessation after AF diagnosis showed a lower risk of dementia compared to patients smoking persistently. These findings may support the promotion of smoking cessation to lower the risk of dementia in patients with new-onset AF.

Funding Acknowledgement

Type of funding sources: None.

P4780Effectiveness and safety of non-vitamin k antagonist oral anticoagulants in patients with atrial fibrillation and valvular heart disease

Background

Patients with atrial fibrillation (AF) often have concomitant valvular heart disease (VHD), especially in Asia. There are limited data on non-vitamin K antagonist oral anticoagulants (NOAC) impact on outcomes for stroke prevention and bleeding for these patients in real world clinical practice.

Purpose

To investigate the effectiveness and safety of NOACs compared with warfarin in patients with AF and associated Evaluated Heartvalves, Rheumatic or Artificial (EHRA) type 2 VHD.

Methods

We identified oral anticoagulants naive patients with AF and EHRA type 2 VHD from the Korean National Health Insurance Service database between 2014 and 2016 (n=2,671 taking warfarin; n=3,058 taking NOAC). Six clinical outcomes including ischemic stroke, intracranial hemorrhage (ICH), gastrointestinal bleeding (GI), major bleeding, all-cause death, and their composite outcome and fatal clinical events (any events that led to death within 30-day of its occurrence) were evaluated. Inverse probability of treatment weighting (IPTW) method was used to balance covariates between the two groups.

Results

After weighted using 5% trimmed IPTW method (n=2371 taking warfarin; n=2792 taking NOAC), the mean age was 71.2 years, male was 57% and CHA2DS2-VASc score was 3.9. During a mean 1.4-year follow-up, weighted incidence rate of ischemic stroke, ICH, GI bleeding, and all-cause death were lower in the NOAC group than in the warfarin group. Compared to warfarin, NOACs were associated with lower risks of ischemic stroke (hazard ratio [HR] 0.71, 95% confidence interval [CI] 0.53–0.96), GI bleeding (HR 0.50, 95% CI 0.35–0.72) and major bleeding (HR 0.61, 95% CI 0.45–0.80). Although NOAC and warfarin groups showed similar incidence rate of ICH, NOAC group was associated with a significantly lower risk of fatal ICH compared to warfarin group (HR 0.28, 95% CI 0.07–0.83). Overall, NOACs were associated with a lower risk of the composite outcome (HR 0.68, 95% CI 0.58–0.80). For an exploratory analysis, patients with EHRA type 1 VHD (n=366 taking warfarin; n=345 taking NOAC) was evaluated. In multivariable Cox regression analysis, NOAC group showed a comparable risk of ischemic stroke, ICH, all-cause death and composite outcome.

Clinical outcome in AF patients with VHD

Conclusion

In this nationwide Asian AF population with EHRA type 2 VHD, NOAC use was associated with lower risks of ischemic stroke, major bleeding, all-cause death, and the composite outcome compared to warfarin.

Prevalence and molecular characterisation of Giardia duodenalis in calves with diarrhoea

The aim of this study was to investigate the prevalence of Giardia duodenalis in diarrhoeal faeces from calves that were reared in Korea using PCR and ELISA. Diarrhoeal faecal samples were collected from 590 calves (<3 months old) throughout the country from November 2013 through March 2015. Data were analysed according to the region of collection, season, and type of diarrhoea. Of the 590 collected faecal samples, 77 (13.1 per cent) and 78 (13.2 per cent; true prevalence 9.1 per cent) tested positive by PCR and ELISA, respectively. The results from both testing methods were in agreement in 501 (84.9 per cent) samples, with a κ value of 0.34, which suggests fair agreement. The PCR results showed a higher prevalence in summer and in cases of haemorrhagic diarrhoea (P<0.05), while the ELISA results showed a lower prevalence in cases of pasty diarrhoea (P<0.05). Phylogenetic analysis of the β-giardin gene sequences of G duodenalis showed that the sequences detected in this study belonged to assemblage E, which is specific to cattle and livestock. The higher prevalence of giardiasis in calves with haemorrhagic diarrhoea found in this study differed from previous studies. Therefore, researchers and veterinarians should be aware of the possible involvement of giardiasis in haemorrhagic diarrhoea.

Molecular cloning and characterization of a novel low temperature-induced gene, blti2, from barley (Hordeum vulgare L.)

The Suppression Subtractive Hybridization (SSH) was used to isolate large numbers of low temperature-induced genes from the cold-treated winter barley (Hordeum vulgare L. cv. Dongbori). One hundred and sixty blti (barley low temperature-induced) cDNA clones were obtained. Northern blot analyses showed that several blti clones were differentially expressed by treatment of low temperature, NaCl, dehydration and ABA. One of the clones, blti2, was induced from 3 to 72 h after cold treatment while its transcript was detected only at 12 h after ABA treatment, indicating that the expression of blti2 by low temperature was regulated by an ABA-independent pathway. The full-length cDNA sequences were 944 nucleotides long and the open reading frame consisted of 492 nucleotides encoding 164 amino acids. Nucleotide sequences showed no sequence homology with the previously reported low temperature-responsive (LTR) barley genes, and the deduced amino acid sequences revealed that the blti2 contains three membrane-spanning regions. These results suggest that blti2 is a novel transmembrane protein induced by low temperature.

Chronic heart failure model with sequential ligation of the homonymous artery and its diagonal branch in the sheep

We report a reliable chronic heart failure model in sheep using sequential ligation of the homonymous artery and its diagonal branch. After a left anterior thoracotomy in Corridale sheep, the homonymous artery was ligated at a point approximately 40% of the distance from the apex to the base of the heart, and after 1 hour, the diagonal vessel was ligated at a point at the same level. Hemodynamic measurements were done preligation, 30 minutes after the homonymous artery ligation, and 1 hour after diagonal branch ligation. The electrocardiograms were obtained as needed, and cardiac function was also evaluated with ultrasonography. After a predetermined interval (2 months for five animals and 3 months for two animals), the animals were reevaluated in the same way as before, and were killed for postmortem examination of their hearts. All seven animals survived the experimental procedures. Statistically significant decreases in systemic arterial blood pressure and cardiac output and increases in pulmonary artery capillary wedge pressure were observed 1 hour after sequential ligation of the homonymous artery and its diagonal branch. Untrasonographic analyses demonstrated variable degrees of anteroseptal dyskinesia and akinesia in all animals. The data from animals at 2 months after coronary artery ligation showed significant increases in central venous pressure, pulmonary artery pressure, and pulmonary artery capillary wedge pressure. Left ventricular enddiastolic dimension and left ventricular end-systolic dimension on ultrasonographic studies were also increased. Electrocardiography showed severe ST elevation immediately after the ligation and pathologic Q waves were found at 2 months after ligation. The thin walled infarcted areas with chamber enlargement were clearly seen in the hearts removed at 2 and 3 months after ligation. In conclusion, we could achieve a reliable ovine model of chronic heart failure using a simple concept of sequential ligation of the homonymous and diagonal arteries. This animal model was comparable to the clinical situation.

CORRELATION OF FAS AND FAS LIGAND EXPRESSION WITH REJECTION STATUS OF TRANSPLANTED HEART IN HUMAN1

BACKGROUND

Activation of pro-apoptotic systems has been proven in rejection model of animal heart transplantation. The role of Fas and Fas ligand (FasL) in graft rejection is not fully understood, and the expression changes of these genes in human transplanted heart have not been elucidated.

METHODS

Endomyocardial biopsy samples were taken from 13 consecutive patients undergoing heart transplantation at various times, and they were classified into rejection (REJ, grade 3A or more) and lack of rejection (TOL, grade 1B or less) by International Society of Heart and Lung Transplantation rejection grade. Semiquantitative reverse transcription-polymerase chain reaction and immunohistochemistry were performed to evaluate the status of Fas and FasL expression in each sample.

RESULTS

Fas was constitutively expressed both in REJ and TOL specimens (expression levels normalized by glyceraldehyde-3-phosphate dehydrogenase expression in semiquantitative reverse transcription-polymerase chain reaction of REJ vs. TOL, 0.842+/-0.096 vs. 0.848+/-0.103, P=0.776); however, FasL expression was detected in 66% of REJ samples and 40% of TOL samples. Normalized levels of FasL expression were 0.591+/-0.494 (REJ) and 0.383+/-0.507 (TOL) (P<0.05). FasL was expressed by cardiomyocytes as well as graft-infiltrating cells.

CONCLUSIONS

This up-regulation of FasL may be one of possible mechanisms of apoptosis in rejection process of human cardiac allograft.

Korean status of alcoholics and alcohol-related health problems

Recent changes in the socioeconomic status of Korea have caused big differences in alcohol-related social and health problems. The traditional trait of drinking mild fermented beverages with nutritional side dishes and meals has shifted to drinking strongly distilled liquors without any side dishes. Moreover, the alcohol consumption per adult capita of Korea is now 8.1 liters, which parallels the level of other developed countries; it used to be 1.0 liter in 1960 and 7.0 liters in 1980, respectively. But the alcohol consumption per capita of adult males is now 18.4 liters. Consequently, the national incidence of alcohol-related diseases and accidents has rapidly increased. Korean adult males have the highest risk of the incidence of hepatoma. The rate of car accidents caused by drunken driving is about 10-fold higher than in any other developed country.

Chronic ethanol consumption affects glutathione status in rat liver

There is no consensus yet on the role of oxidative stress in the nutritional outcome of chronic ethanol feeding and the status of cellular antioxidative defense systems against ethanol toxicity. In this study, chronic alcohol consumption in humans was reproduced in Sprague-Dawley rats to investigate the effect of ethanol ingestion on the regulation of oxidative stress in liver with a special focus on glutathione. Adult male rats were given 36% of total energy as alcohol in the Lieber-DeCarli liquid diet for 6 wk. The control group was pair-fed the diet containing isocaloric dextrin-maltose instead of ethanol. Chronic ethanol ingestion enhanced expression of cytochrome P450 II E1 in the liver, but did not significantly alter either the level of hepatic thiobarbituric acid reactive substances or the carbonyl group content of proteins. The hepatic concentrations of total and reduced glutathione and the activities of catalase, glutathione reductase and glutathione S-transferase were significantly higher in the ethanol group than in the control group. The activities of glutathione peroxidase and glucose-6-phosphate dehydrogenase were significantly lower in the ethanol group than in controls. Chronic ethanol consumption by well-nourished rats for 6 wk increased enzyme activities related to the recycling and utilization of glutathione in the liver. Such an enhancement in the activities of the hepatic antioxidative defense system may be one of the protective mechanisms of the body against oxidative tissue damage caused by ethanol-induced free radicals.

Reciprocal change in angiotensinogen mRNA expression in rat myocardium and liver after myocardial infarction

The aim of this study was to analyze sequential change of angiotensinogen (Ao) mRNA expression in rat liver and noninfarcted myocardium after myocardial infarction (MI). Female sprague-Dawley rats were subjected either to left coronary artery occlusion or sham operation. Three weeks after MI, coronary artery ligation resulted in comparable infarct sizes. A hypokinetic thin anterior wall and remarkable dilatation of the left ventricle, as well as decreased contractility (left ventricular end-systolic dimension = 6.0+/-0.4, 3.3+/-0.2, LV end-diastolic dimension = 7.9+/-0.3, 5.9+/-0.2 mm, and fractional shortening = 25.3+/-3.1%, 45.1+/-3.3%) were shown in the MI and sham group, respectively, by echocardiography (P < 0.01). Experimental MI caused a significant fall in systolic blood pressure (MI 90+/-5.0, vs sham 130+/-7.5 mmHg; P< 0.01) and significantly higher left ventricular end-diastolic pressure (MI 21+/-1.5, vs sham 11+/-1.0 mmHg: P < 0.01). At 4, 18, and 24h after MI, liver Ao mRNA levels, as shown by Northern blot analysis, had increased by up to four times (Ao/glyceraldehyde-3-phosphate dehydrogenase (GAPDH) = 1.4+/-0.1 and 6.0+/-0.2 at baseline and 4h after MI, respectively (P < 0.01). After sham surgery, however, the corresponding increase was slight (maximal 1.5-fold). Three days after MI, liver mRNA had returned to the baseline level. In contrast, ATG mRNA expression in noninfarcted myocardium, as shown by reverse transcription-polymerase chain reaction and Southern blotting, decreased transiently during the acute phase. It returned to its baseline level within 3 days, and then increased further (Ao/ GAPDH = 2.9+/-0.6, 0.3+/-0.1, 3.2+/-0.8, and 3.7+/-0.8 at baseline, 24h, 3 days, and 3 weeks after MI, respectively). In conclusion, it can be stated that after MI, the Ao gene contributes, acutely in the liver and chronically in the myocardium, to the maintenance of hemodynamic homeostasis during the acute phase and ventricular remodeling during the chronic phase.

Glutathione recycling is attenuated by acute ethanol feeding in rat liver

The mechanism for ethanol-induced oxidative stress has been disputed because of the controversies on modulation of radical generating and scavenging activities by ethanol. In the present work, we attempted to clarify the acute effect of ethanol on the radical generating system as well as the radical scavenging system. For that purpose, chow-fed rats were given ethanol (5 g/kg) or isocaloric glucose solution by intragastric intubation and placed at 32 degrees C for 6 hr. Acute ethanol administration enhanced the expression of cytochrome P450 II E1(CYP II E1) in the liver and attenuated the activities of hepatic glutathione peroxidase (GPx) and reductase (GR). It also caused a significant increase in the level of hepatic thiobarbituric acid reactive substances (TBARS), an indicator of lipid peroxidation. On the other hand, acute ethanol feeding had no effect on the activities of catalase, xanthine oxidase (XO), glutathione transferase (GST) and glucose-6-phosphate dehydrogenase (G6PDH). From this result, it is suggested that acute ethanol administration causes the oxidative tissue damage by CYP II E1-associated radical generation and the decreased radical scavenging function due to the reduced activities of hepatic glutathione recycling system such as GPx and GR.