Safety of recanalization therapy in patients with acute ischemic stroke on direct oral anticoagulants: A sub-analysis of PASTA registry study

BACKGROUND

The safety of intravenous recombinant tissue plasminogen activator (rtPA) and mechanical thrombectomy (MT) in patients treated with direct oral anticoagulants (DOACs) before stroke has not been fully investigated. Therefore, we aimed to investigate the safety of recanalization therapy in patients receiving DOACs.

METHODS

We assessed data from a prospective multicenter registry of patients with stroke, including those with acute ischemic stroke (AIS) treated with rtPA and/or MT who were administered DOACs. We evaluated the safety of recanalization considering the DOACs dosage and interval between the last DOAC intake and recanalization.

RESULTS

The final analysis included 108 patients (women, n = 54; median age, 81 years; DOAC overdose, n = 7; appropriate dose, n = 74; and inappropriate low dose, n = 27). The rate of any ICH differed significantly among overdose-, appropriate dose-, and inappropriate-low dose DOACs groups (71.4, 23.0, and 33.3%, respectively; P = 0.0121), whereas no significant difference was observed in respect of symptomatic ICH (P = 0.6895). Multivariate analysis showed that the National Institutes of Health Stroke Scale score on admission (odds ratio [OR]: 1.06, 95% confidence interval [CI]: 1.01-1.11; P = 0.0267) and overdose-DOAC (OR: 8.40, 95% CI: 1.24-56.88; P = 0.0291) were independently associated with any ICH. No relationship was observed between the timing of the last DOAC intake and occurrence of ICH in patients treated with rtPA and/or MT (all P > 0.05).

CONCLUSION

Recanalization therapy during DOAC treatment may be safe in selected patients with AIS, if it is performed >4 h after the last DOAC intake and the patient is not overdosed with DOACs.

REGISTRATION

https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000034958.

Application of carbamyl in structural optimization

Carbamyl is considered a privileged structure in medicinal chemistry. It has a wide range of biological activities such as antimicrobial, anticancer, anti-epilepsy, for which the best evidence is a number of marketed carbamyl-containing drugs. Carbamyl is formed of primary amine and carbonyl moieties that act as hydrogen bond donors and hydrogen acceptors with residues of targets respectively, which are benefit for improving pharmacological activities. In other cases, the introduced carbamyl improves drug-like properties including oral bioavailability. In this review, we introduce the carbamyl-containing drugs and the application of carbamyl in structural optimization as a result of enhancing activities or/and drug-like properties.

Control of Anticoagulation Therapy in Patients with Atrial Fibrillation Treated with Warfarin: A Study from the Chinese Atrial Fibrillation Registry

Background

Several factors determine the efficacy of warfarin anticoagulation in patients with non-valvular atrial fibrillation (NVAF). This study aimed to use data from the Chinese Atrial Fibrillation Registry study to assess the control of anticoagulation therapy in Chinese patients with NVAF treated with warfarin.

Material/Methods

From the Chinese Atrial Fibrillation Registry study the anticoagulant use and dosing, the time in therapeutic range (TTR) of the international normalized ratio (INR), and standard deviation of the observed INR values (SD_INR), and their influencing factors were evaluated.

Results

The median INR and SD_INR were 2.04 (IQR 1.71–2.41) and 0.50 (IQR, 0.35–0.69), respectively. The median TTR was 51.7% (IQR, 30.6–70.1%) and only 25.1% had a TTR ≥70%. Age was ≥70 years (OR, 0.72; 95% CI, 0.55–0.94; P=0.015), bleeding history (OR 0.48; 95% CI, 0.23–0.89; P=0.029), the use of a single drug (OR, 0.62; 95% CI, 0.42–0.92; P=0.016), more than drug (OR, 0.60; 95% CI, 0.41–0.88; P=0.009), and lack of assessment of bleeding risk (OR, 0.72; 95% CI, 0.54–0.97; P=0.033) were associated with TTR <70% (INR 2.0–3.0). Coronary heart disease (CHD) and peripheral artery disease (PAD) (OR, 0.69; 95% CI, 0.52–0.90; P=0.007) and diabetes mellitus (OR, 0.79; 95% CI, 0.62–0.99; P=0.044) were associated with increased variability in INR (SD_INR ≥0.5).

Conclusions

In Chinese patients with NVAF, warfarin anticoagulation was associated with lower TTR and less stable anticoagulation than in current guidelines, and risk factors for reduced safety and efficacy were identified.

Laparoscopic surgery in rectal cancer patients taking anti-thrombotic therapy

Background: Several previous studies have shown that laparoscopic resection of rectal cancer is a feasible option. However, its safety and efficacy in patients receiving long-term anti-thrombotic therapy (AT) remain unclear.Material and methods: We retrospectively reviewed 364 patients who underwent elective resection for rectal cancer via a laparoscopic approach between 2007 and 2018 in our institute. Patients were classified according to the long-term use of AT. AT was interrupted perioperatively with or without heparin bridging therapy in all anti-thrombotic users. Clinicopathological factors and surgical outcomes were analyzed between patient groups.Results: Thirty-two patients (9%) receiving AT were older and had lower albumin and hemoglobin levels than those not receiving AT (the non-AT group), and were predominantly male. Estimated blood loss and operative time in the AT group (median: 50 mL and 294 min) did not differ from those in the non-AT group (median: 20 mL and 295 min). There were no intergroup differences in the frequencies of other postoperative complications and oncological outcomes.Conclusions: Our results at the very least can support that laparoscopic surgery for rectal cancer is a safe and feasible option for patients taking long-term AT discontinued perioperatively.

Mining association rules between stroke risk factors based on the Apriori algorithm

BACKGROUND

Stroke is a frequently-occurring disease and is a severe threat to human health.

OBJECTIVE

We aimed to explore the associations between stroke risk factors.

METHODS

Subjects who were aged 40 or above were requested to do surveys with a unified questionnaire as well as laboratory examinations. The Apriori algorithm was applied to find out the meaningful association rules. Selected association rules were divided into 8 groups by the number of former items. The rules with higher confidence degree in every group were viewed as the meaningful rules.

RESULTS

The training set used in association analysis consists of a total of 985,325 samples, with 15,835 stroke patients (1.65%) and 941,490 without stroke (98.35%). Based on the threshold we set for the Apriori algorithm, eight meaningful association rules were obtained between stroke and its high risk factors. While between high risk factors, there are 25 meaningful association rules.

CONCLUSIONS

Based on the Apriori algorithm, meaningful association rules between the high risk factors of stroke were found, proving a feasible way to reduce the risk of stroke with early intervention.

Laparoscopic surgery in colon cancer patients treated with chronic anti-thrombotic therapy

BACKGROUND

Anti-thrombotic medications are commonly used for the treatment and prevention of cardiovascular diseases. Laparoscopic resection of colon cancer has generally been accepted with favorable outcomes being reported in randomized control trials. However, the safety and efficacy of laparoscopic surgery for colon cancer patients receiving chronic anti-thrombotic therapy (AT) remain unclear.

METHODS

We identified 951 patients who underwent elective resection for colon cancer between 2009 and 2016 from our database. Patients were classified according to the surgical approach and chronic AT. Clinicopathological factors and surgical outcomes were analyzed between patient groups. Patients' backgrounds were matched using propensity scores in laparoscopic surgery.

RESULTS

Anti-thrombotic drugs were chronically used in 135 patients. Among 714 patients who underwent laparoscopy-assisted surgery, 96 received AT. The laparoscopic approach was superior to open surgery in terms of bleeding, surgical site infections, and hospital stay in patients receiving AT. In laparoscopy-assisted surgery, the AT group patients were older and showed lower hemoglobin and albumin levels than those not receiving AT (non-AT group), and were predominantly male. After propensity score matching, estimated blood loss and operative times were similar between the two groups (93 matched patients). The frequencies of postoperative bleeding (2.2%) and thrombotic complications (0%) in the AT group did not significantly differ from those in the non-AT group (1.1 and 0%, respectively). Moreover, AT did not affect survivals.

CONCLUSION

Laparoscopic approach appears to be safer and beneficial for colonic cancer patients receiving long-term AT. Bleeding and thrombotic events associated with laparoscopic surgery were not significantly affected by AT.

Low risk of ICH after reperfusion therapy in acute stroke patients treated with direct oral anti-coagulant

BACKGROUND

The safety of intravenous thrombolysis (IVT) and endovascular therapy (EVT) in patients treated with DOAC is unclear. We investigated whether recanalization therapy in patients treated with DOAC is safe.

METHODS

A nationwide, multicenter, retrospective cohort questionnaire survey was conducted to investigate the: (1) frequency of intracerebral hemorrhage (ICH) after recanalization therapy in patients treated with DOAC; (2) independent factors related to ICH; (3) relationship between last intake time of DOAC and ICH; and (4) comparison of ICH frequency between patients treated with DOAC, vitamin K antagonist (VKA), and no-anticoagulation (no-ACT) (control).

RESULTS

One hundred eighteen stroke centers returned the questionnaire and 100 patients (56 IVT alone, 29 EVT alone, and 15 both IVT and EVT) on DOAC were registered. The frequency of asymptomatic and symptomatic (≥4-point NIHSS score increase) ICH within 24h in DOAC patients were 18% and 2%, and were not different compared with the VKA and no-ACT groups (p=0.728; and p=0.626). On multivariate analysis, systolic blood pressure (OR, 1.04; p<0.001) and blood glucose (OR, 1.02; p=0.019) were independent factors for ICH. Among the 52 patients with a known last intake time of DOAC, the rate of ICH was higher in patients ≤4h from last intake than those >4h (38% vs. 10%, p=0.033).

CONCLUSIONS

Risk of ICH after reperfusion therapy in patients treated with DOAC should be low. Systolic blood pressure, glucose level, and DOAC intake time appear to be factors for ICH.

Direct Oral Anticoagulants for the Treatment of Venous Thromboembolism in Japan

Direct oral anticoagulants (DOACs) were developed to compensate for the demerits of warfarin. In Japan, three factor Xa inhibitors are used for the treatment of venous thromboembolism (VTE): edoxaban, rivaroxaban, and apixaban. Despite problems, such as the inability to monitor their effect and the lack of an antidote, these inhibitors have the same efficacy as conventional treatment with warfarin, and they are associated with a significantly high degree of safety in relation to hemorrhagic complications. East Asians, including Japanese, suffer from hemorrhage more frequently; therefore, DOACs are considered to be highly effective. Although there is no evidence to date, DOACs may be effective in a wide variety of ways, including the possibility that they prevent recurrence over the long term, reduce the length of hospitalization, allow treatment to be started on an outpatient basis, and be effective in cancer patients.

Major determinants for the selecting antithrombotic therapies in patients with nonvalvular atrial fibrillation in Japan (JAPAF study)

Background

Oral anticoagulants (OACs) can help prevent stroke in patients with nonvalvular atrial fibrillation (NVAF). The aim of this study was to characterize the use of OACs other than direct thrombin inhibitors (DTIs) for NVAF.

Methods

Patients with NVAF taking antithrombotics other than DTIs were enrolled in this cross-sectional study. Patient demographics and medication history were collected, and the patients were classified as taking antiplatelet monotherapy (AP), anticoagulant monotherapy (AC), or combination therapy (AP+AC). OAC users were also stratified as naïve (N; initiated within 6 months), switcher (S; switched within 6 months), or prevalent user (P; continued for >6 months).

Results

A total of 3053 patients (AP, 216; AC, 2381; AP+AC, 456) from 268 sites were enrolled from 2012 to 2013. Significant differences were observed in CHADS₂ scores (AP/AC/AP+AC: 2.0/2.1/2.7, P<0.0001), angina complications (20.1/8.6/32.1, P<0.0001), myocardial infarction (5.1/2.8/18.1, P<0.0001), prothrombin time–international normalized ratio (PT–INR) (−/2.00/1.94, P=0.0350), and others. There were 2831 OAC users (N, 328; S, 213; P, 2290). Significant differences were observed in history of bleeding (N/S/P: 2.4/9.4/4.5, P<0.001), PT–INR (1.83/2.01/2.00, P<0.0001), and others.

Conclusions

Patients taking AP+AC had higher CHADS₂ scores than those taking an AP or AC alone. Additionally, the combination therapy (AP+AC) was preferred in patients with cardiovascular comorbidity. Changes in AC regimens were not influenced by CHADS₂ scores or complications but influenced by history of bleeding. These characteristics were thus identified as major factors affecting the selection of antithrombotic regimens other than DTIs in patients with NVAF.

Total Thrombus-Formation Analysis System (T-TAS) Can Predict Periprocedural Bleeding Events in Patients Undergoing Catheter Ablation for Atrial Fibrillation

Background

Non–vitamin K antagonist oral anticoagulants are used to prevent thromboembolism in patients with atrial fibrillation. The T‐TAS “Total Thrombus‐formation Analysis System” (Fujimori Kogyo Co Ltd) was developed for quantitative analysis of thrombus formation using microchips with thrombogenic surfaces (collagen, platelet chip [PL] ; collagen plus tissue factor, atheroma chip [AR]). We evaluated the utility of T‐TAS in predicting periprocedural bleeding in atrial fibrillation patients undergoing catheter ablation (CA).

Methods and Results

After exclusion of 20 from 148 consecutive patients undergoing CA, the remaining 128 patients were divided into 2 treatment groups: the warfarin group (n=30) and the non–vitamin K antagonist oral anticoagulants group (n=98). Blood samples obtained on the day of CA (anticoagulant‐free point) and at 3 and 30 days after CA were used in T‐TAS to compute the thrombus formation area under the curve (AUC; AUC for the first 10 minutes for PL tested at flow rate of 24 μL/min [PL₂₄‐AUC₁₀]; AUC for the first 30 minutes for AR tested at flow rate of 10 μL/min [AR₁₀‐AUC₃₀]). AR₁₀‐AUC₃₀ and PL₂₄‐AUC₁₀ levels were similar in the 2 groups on the day of CA. Levels of AR₁₀‐AUC₃₀, but not PL₂₄‐AUC₁₀, were significantly lower in the 2 groups at days 3 and 30 after CA. Multiple logistic regression analyses identified the AR₁₀‐AUC₃₀ level on the day of CA as a significant predictor of periprocedural bleeding events (odds ratio 5.7; 95% CI 1.54–21.1; P=0.009). Receiver operating characteristic analysis showed that the AR₁₀‐AUC₃₀ level on the day of CA significantly predicted periprocedural bleeding events (AUC 0.859, 95% CI 0.766–0.951; P<0.001). The cutoff AR₁₀‐AUC₃₀ level was 1648 for identification of periprocedural bleeding events.

Conclusions

These results suggested that the AR₁₀‐AUC₃₀ level determined by T‐TAS is a potentially useful marker for prediction of bleeding events in atrial fibrillation patients undergoing CA.

Different risk factors for bleeding and discontinuation between dabigatran and rivaroxaban

BACKGROUND

It is unclear whether risk factors for bleeding and discontinuation are different between dabigatran and rivaroxaban.

METHODS AND RESULTS

We enrolled consecutive patients with atrial fibrillation who received dabigatran or rivaroxaban, had a CHADS2 score >1 and creatinine clearance >30ml/min. During this period, only dabigatran and rivaroxaban were available as non-vitamin K oral anticoagulants (NOACs) in our hospital. We compared the clinical and demographic data and the incidence of bleeding for one year between dabigatran group and rivaroxaban group. As a result, the dabigatran group consisted of 177 patients and the rivaroxaban group consisted of 179 patients. The incidence of discontinuation was significantly higher in the dabigatran group than in the rivaroxaban group (27.7% vs. 13.4%, p<0.001). Multivariate analysis, even after propensity score-matching analysis, revealed that there were no independent risk factors for bleeding in the dabigatran group, while in the rivaroxaban group, use of antiplatelet therapy was an independent factor correlating with bleeding.

CONCLUSIONS

The risk factors for bleeding may be different between dabigatran and rivaroxaban. To avoid bleeding, rivaroxaban should be prescribed with caution or avoided in patients using antiplatelet therapy. Upon discontinuation, rivaroxaban may be more favorable than dabigatran.

Rationale and design of a study exploring the efficacy of once-daily oral rivaroxaban (X-TRA) on the outcome of left atrial/left atrial appendage thrombus in nonvalvular atrial fibrillation or atrial flutter and a retrospective observational registry providing baseline data (CLOT-AF)

There are still many unresolved issues concerning patient outcomes and prognostic factors in patients with atrial fibrillation (AF) and left atrial/left atrial appendage (LA/LAA) thrombi. Rivaroxaban (Xarelto®), a potent and highly selective oral, direct factor Xa inhibitor, is a new therapeutic option in this setting. The planned study program will consist of a prospective interventional study (X-TRA) and a retrospective observational registry (CLOT-AF). The primary objective of the X-TRA study is to explore the efficacy of rivaroxaban in the treatment of LA/LAA thrombi in patients with nonvalvular AF or atrial flutter, scheduled to undergo cardioversion or AF ablation, in whom an LA/LAA thrombus has been found on transesophageal echocardiography (TEE) before the procedure. The primary end point is the complete LA/LAA thrombus resolution rate at 6 weeks of end of treatment confirmed by TEE. The secondary objectives are to describe categories of thrombus outcome in patients (resolved, reduced, unchanged, larger, or new) confirmed on TEE at the end of treatment (after 6 weeks of treatment), incidence of the composite of stroke and noncentral nervous system systemic embolism at the end of treatment and during follow-up, and incidence of all bleeding at the end of treatment and during follow-up. The objective of the CLOT-AF registry is to provide retrospective thrombus-related patient outcome data after standard-of-care anticoagulant treatment in patients with nonvalvular AF or atrial flutter, who have TEE-documented LA/LAA thrombi. The data will be used as a reference for the prospective X-TRA study. In conclusion, X-TRA and CLOT-AF will provide some answers to the many unresolved issues concerning patient outcomes and prognostic factors in patients with AF and LAA thrombi. Results from this study program would provide the first prospective interventional study (X-TRA) and a large international retrospective observational registry (CLOT-AF) on the prevalence and natural history of LA/LAA thrombi. Unique data on clot resolution with rivaroxaban in a prospective cohort would be obtained in X-TRA.

Atrial fibrillation at mid-term after bioprosthetic aortic valve replacement – implications for anti-thrombotic therapy

BACKGROUND

Little is known about mid-term (3-month) postoperative atrial fibrillation (MT-POAF) in patients treated with bioprosthetic aortic valve replacement (BAVR). The aim of this study was to describe the natural history, identify the predictors and investigate the potential consequences in terms of anti-thrombotic therapy.

METHODS AND RESULTS

During a longitudinal, prospective study, 219 patients were treated with BAVR early (7 days) and at mid-term postoperatively (30 and 90 days). POAF was monitored and risk factors were identified on logistic regression analysis. History of previous AF (OR, 3.08; 95% CI: 1.35-6.98), early POAF (OR, 5.93; 95% CI: 2.96-11.8), and BMI (per 5 kg/m(2): OR, 1.46; 95% CI: 1.03-2.09), were independent predictors for MT-POAF whereas sex, age and Euroscore were not. Results were identical when restricted to the 176 patients free from preoperative AF. In this subgroup, 36 patients (20.4%) had MT-POAF; 33 out of 174 (18.7%) would have required anticoagulation (CHA2DS2VASc score ≥ 1). Conversely, patients with BMI <27.7 and sinus rhythm at early follow-up had a very low risk of MT-POAF (OR, 0.16; 95% CI: 0.06-0.42).

CONCLUSIONS

There was a higher than expected occurrence of MT-POAF in patients treated with BAVR, particularly in overweight patients with early POAF. This raises the question of implementing an anti-thrombotic therapy in these patients at higher risk of delayed atrial arrhythmia.

Association between smoking habits and the first-time appearance of atrial fibrillation in Japanese patients: Evidence from the Shinken Database

BACKGROUND

We previously reported a cross-sectional analysis regarding the relationship between smoking and atrial fibrillation (AF) in a single hospital-based cohort with Japanese patients, but the effect of cessation of smoking and/or total tobacco consumption were unclear.

METHODS AND RESULTS

We used data from the Shinken Database 2004-2011 (men/women, n=10,714/6803, respectively), which included all new patients attending the Cardiovascular Institute between June 2004 and March 2012. After excluding those previously diagnosed with AF (n=2296), 15,221 patients (men/women, n=9016/6205) were analyzed. During the follow-up period of 2.0±2.1 years (range 0.0-8.1), the incidence rates of new AF in smokers and non-smokers were 9.0 and 5.0 per 1000 patient-years, respectively. In adjusted models with Cox regression analysis, smokers were independently associated with new AF [hazard ratio (HR) 1.47, 95% confidence interval (CI) 1.09-2.00]. Also, current smokers (HR 1.81, 95% CI 1.17-2.79) and smokers with Brinkman index ≥800 (HR 1.69, 95% CI 1.05-2.70) were independently associated with new AF. However, in current smokers, the HRs were not different by Brinkman index (Brinkman index <800/≥800; HR 1.81/1.82, 95% CI 1.07-3.05/0.94-3.51, respectively).

CONCLUSIONS

Smoking was independently associated with the first-appearance of AF in patients in sinus rhythm, especially when the patients continued their smoking habit. However, in patients who continued smoking, difference by total tobacco consumption was not observed, suggesting the significance of cessation of smoking for preventing AF. Our data are limited because of a single hospital-based nature and a relatively short observation period.

Effects of 6-(4-chlorophenoxy)-tetrazolo[5,1-a]phthalazine on anticoagulation in mice and the inhibition of experimental thrombosis in rats

: Thrombosis is a major complication that could be fatal in acute or chronic cardio-cerebral-vascular diseases. Therefore, the development of novel agents for anticlotting and the prevention of thrombosis and cardiovascular diseases are clinically significant. This study aimed to evaluate the anticoagulant and antithrombotic effects of 6-(4-chlorophenoxy)-tetrazolo[5,1-a]phthalazine (Q808), a new phthalazine tetrazole derivative. Bleeding time, clotting time, and serum calcium ion (Ca) concentration were assessed in mice, whereas arteriovenous thrombus weight and plasma prothrombin time were evaluated in rats, and platelets Ca influx was determined in rabbit. Daily oral administration of Q808 at 25, 50, or 100 mg/kg for 3 days significantly delayed bleeding time and clotting time in mice compared with controls. Q808 administration at 50 mg/kg significantly reduced experimental thrombus weight by 62.6% and delayed plasma prothrombin time by 58.7% in rats, whereas 50 and 100 mg/kg of Q808 daily significantly increased serum Ca concentration in mice. Q808 at 0.2, 0.4, and 0.8 mg/mL significantly inhibited thrombin-induced Ca influx in rabbit platelets. Our results suggest that Q808 at 25-200 mg/kg daily exerts anticoagulant and antithrombotic effects, and its mechanisms of action may involve both the intrinsic and extrinsic coagulation pathways that inhibit certain coagulation factors and platelet functions.

Trends in the incidence and survival of intracerebral hemorrhage by its location in a Japanese community

BACKGROUND

No previous population-based studies have examined secular trends in the incidence of intracerebral hemorrhage (ICH) by its location.

METHODS AND RESULTS

 We established 3 cohorts consisting of residents of Hisayama, Japan, aged ≥40 years without a history of stroke or myocardial infarction in 1961 (the first cohort, n=1,618), in 1974 (the second cohort, n=2,038), and in 1988 (the third cohort, n=2,637). Each cohort was followed for 13 years. The age- and sex-adjusted incidence of ICH significantly declined from the first to the second cohort and showed no further change in the third cohort. With regard to the ICH location, the incidence of putaminal hemorrhage decreased steadily, mainly in subjects aged 60-69 years, whereas the incidence of thalamic hemorrhage increased, especially in those aged ≥70 years. Both hypertension and alcohol intake were strong risk factors for ICH in the first cohort, but their influence declined with time. Blood pressure levels in hypertensive subjects decreased significantly, and the proportion of current drinkers decreased slightly over the study period.

CONCLUSIONS

Our findings suggest that the ICH incidence steeply declined from the 1960s to the 1970s in Japan as a result of the reduced influence of hypertension and alcohol intake, but that this decline has leveled off since then, probably because of the increased incidence of thalamic hemorrhage in the elderly in recent years. 

Effects of smoking habit on the prevalence of atrial fibrillation in Japanese patients with special reference to sex differences

BACKGROUND

Tobacco smoking is a well-known risk factor for cardiovascular disease, but controversial results have been reported regarding its relationship with atrial fibrillation (AF). Moreover, no study on the relationship between smoking and AF has yet been undertaken in a Japanese context.

METHODS AND RESULTS

We used data from the Shinken Database 2004-2011 (men/women, n=10,714/6,803, respectively), which included all new patients attending the Cardiovascular Institute between June 2004 and March 2012. AF was diagnosed in 1,698 and 598 men and women, respectively. In men, smokers were more prevalent in the AF than in the non-AF group (54.5% vs. 44.7%), whereas in women the prevalence of smokers was similar between AF and non-AF groups (14.4% vs. 15.4%). This discrepancy between the sexes seems to derive from a characteristic distribution pattern of smoking habit in women. After adjustment for various cofactors, smoking was independently associated with AF (odds ratio 1.54; 95% confidence interval 1.35-1.75; P<0.001) without a significant interaction between sex categories (P=0.195).

CONCLUSIONS

Smoking was independently associated with AF without a significant interaction between sex categories among Japanese patients visiting a cardiovascular hospital. Further studies using a prospective cohort design are required to confirm a causal link between smoking and AF in Japanese patients.

Bleeding events and activated partial thromboplastin time with dabigatran in clinical practice

BACKGROUND

Dabigatran has demonstrated promising results for the prevention of strokes in patients with non-valvular atrial fibrillation (NVAF). However, there have been episodes of major bleeding, especially in elderly patients or those with renal dysfunction. The purpose of this study was to retrospectively examine the relationship between the bleeding events and activated partial thromboplastin time (APTT) values under dabigatran usage in the everyday clinical practice. Moreover, we investigated which factors would contribute to the APTT values.

METHODS AND RESULTS

A total of 139 NVAF patients (112 men, 65 ± 11 years) were included. We evaluated the influence of the putative etiological variables and the bleeding score, HAS-BLED score, on APTT values: age greater than 70 years, renal function, gender, dose of dabigatran, and the concomitant prescription of a P-glycoprotein inhibitor. There were 50 patients with an age of ≥ 70 years (36.0%). A P-glycoprotein inhibitor was administered in 18 patients. During the observation period (median 120 days) there was 1 episode of asymptomatic cerebral infarction. There were no intrinsic major bleeding events, however, 11 patients had minor hemorrhagic events. The results of the APTT measurements exhibited a variety of values both among inter- and intra-individuals. On multivariable analysis, significant associations were found between the following risk factors and the APTT values: creatinine clearance, dose of dabigatran, and concomitant use of a P-glycoprotein inhibitor. The minor bleeding events did not correlate with the APTT values, nor HAS-BLED score.

CONCLUSIONS

The APTT values became prolonged under dabigatran usage and exhibited a remarkable diversity. Although major bleeding did not occur unless APTT was prolonged excessively, minor bleeding arose irrespective of the APTT values even within the range of the APTT values not exceeding 80s.

Managing anticoagulation for atrial fibrillation: current issues and future strategies

Although warfarin is superior to aspirin in reducing the risk of stroke in patients with atrial fibrillation, it can increase major bleeds. Hence, physicians stratify patients according to stroke risk to ensure a net benefit. In this review, the CHA(2) DS(2) -VASc stratification scheme used in the latest European Society of Cardiology (2010/12) guidelines will be explained. The greater sensitivity of this scheme, compared to the previous CHADS(2) , more closely delineates patients for whom warfarin is appropriate. The review also anticipates that there will be a wider range of patients who may benefit from the new oral anticoagulants, which show similar or superior efficacy and/or safety to warfarin with a significant reduction in intracranial haemorrhage and do not require routine coagulation monitoring. The role of conventional and new anticoagulant options will also be discussed.

The minimally invasive approach is associated with reduced perioperative thromboembolic and bleeding complications for patients receiving preoperative chronic oral anticoagulant therapy who undergo colorectal surgery

BACKGROUND

The data on the perioperative risk of both thromboembolism and hemorrhage for patients receiving chronic oral anticoagulation who undergo colorectal surgery are sparse. In addition, it is uncertain whether the use of the laparoscopic instead of open technique entails additional risk for these patients. This study aimed to evaluate surgical outcomes, with a particular focus on perioperative thromboembolic and bleeding complications for patients receiving chronic oral anticoagulation therapy who undergo open or laparoscopic colorectal resection.

METHODS

Patients undergoing colorectal resection between 1994 and 2011 on preoperative chronic oral anticoagulant therapy were included in the study. Patient demographics, characteristics, and perioperative outcomes, with particular emphasis on thromboembolism and bleeding risks, were evaluated comparing laparoscopic and open colectomy.

RESULTS

The study enrolled 261 patients receiving chronic anticoagulation therapy (102 laparoscopic colectomy vs 159 open colectomy patients). The patients had a mean age of 57.9 years and a mean body mass index (BMI) of 29.3 kg/m(2). The conversion rate was 8.8 % (n = 9) for laparoscopic operations. Laparoscopic and open cases had comparable BMIs and levels of preoperative hemoglobin. Anastomotic leak, postoperative hospital stay, and surgical-site infection rates were similar for the two groups. Although the laparoscopic group had a significantly greater mean age (p < 0.001) and American Society of Anesthesiology (ASA) score (p = 0.005), the rates for postoperative venous thromboembolism (24.5 vs 2.9 %; p < 0.001), urinary complications (6.9 vs 0 %; p = 0.008), and overall morbidity (44.7 vs 17.7 %; p < 0.001) were lower after laparoscopic surgery. Although the rates for intra- and postoperative blood transfusion were similar, the postoperative hemoglobin levels were significantly higher after laparoscopic surgery. One patient in the laparoscopic group died of sepsis on postoperative day 3.

CONCLUSION

For the patients receiving preoperative chronic anticoagulant therapy who underwent colorectal resection, the laparoscopic approach was associated with lower thromboembolic and hemorrhagic complications than open surgery.

Gender-specific relationship between serum uric acid level and atrial fibrillation prevalence

BACKGROUND

Although various kinds of cardiovascular risk factors have been reported to be associated with atrial fibrillation (AF), the relationship between serum uric acid level and AF has not been fully examined.

METHODS AND RESULTS

Data were collected from a single hospital-based cohort in the Shinken Database 2004-2008 (n=11,123), and consisted of serum uric acid level for 7,155 patients. The association between serum uric acid level and AF prevalence was evaluated on logistic regression. Uric acid significantly increased the crude AF prevalence in both men and women (both, P<0.001). The odds ratio (OR) and 95% confidence interval (95%CI) in the highest tertile compared with the lowest one were 3.368 (2.478-4.578) and 1.408 (1.169-1.695) in women and men, respectively. Uric acid was also significantly associated with other various cardiovascular risk factors for AF. Even after the multivariate model was adjusted using these variables, the effect of uric acid on AF was independent in women (OR, 1.888; 95%CI: 1.278-2.790), but not in men.

CONCLUSIONS

Reflecting the composite of various cardiovascular risk factors, serum uric acid level was apparently associated with AF prevalence. The independent association in women might imply some sex-specific mechanisms. The results should be confirmed in prospective studies.