Thrombotic Profile and Oral Anticoagulation in Asian and Non-Asian Patients With Nonvalvular Atrial Fibrillation

Ethnic Differences in Thrombotic Profiles of Acute Coronary Syndrome Patients and Relationship to Cardiovascular Outcomes: A Comparison of East Asian and White subjects

BACKGROUND

East Asians (EAs), compared to white Caucasians (W), have a lower risk of ischemic heart disease and a higher risk of bleeding with antithrombotic medications. The underlying mechanisms are incompletely understood.

OBJECTIVES

We sought to compare thrombotic profiles of EA and W patients with myocardial infarction (MI) and relate these to cardiovascular outcomes.

METHODS

In a prospective study in the United Kingdom and Korea, blood samples from patients (n = 515) with ST- or non-ST-elevation MI (STEMI and NSTEMI) were assessed using the Global Thrombosis Test, measuring thrombotic occlusion (OT) and endogenous fibrinolysis (lysis time [LT]). Patients were followed for 1 year for major adverse cardiovascular events (MACE) and bleeding.

RESULTS

EA patients showed reduced OT (longer OT) compared to W (646 seconds [470-818] vs. 436 seconds [320-580], p < 0.001), with similar LT. In STEMI, OT (588 seconds [440-759] vs. 361 seconds [274-462], p < 0.001) and LT (1,854 seconds [1,389-2,729] vs. 1,338 seconds [1,104-1,788], p < 0.001) were longer in EA than W. In NSTEMI, OT was longer (OT: 734 seconds [541-866] vs. 580 seconds [474-712], p < 0.001) and LT shorter (1519 seconds [1,058-2,508] vs. 1,898 seconds [1,614-2,806], p = 0.004) in EA than W patients. MACE was more frequent in W than EA (6.3 vs. 1.9%, p = 0.014) and bleeding infrequent. While OT was unrelated, LT was a strong independent predictor of MACE event after adjustment for risk factors (hazard ratio: 3.70, 95% confidence interval: 1.43-9.57, p = 0.007), predominantly in W patients, and more so in STEMI than NSTEMI patients.

CONCLUSION

EA patients exhibit different global thrombotic profiles to W, associated with a lower rate of cardiovascular events.

Prevalence, predictors and management of left atrial appendage thrombogenic milieu in atrial fibrillation with low thromboembolic risk

BACKGROUND

The present study aimed to investigate the prevalence, predictors, and management of left atrial appendage (LAA) thrombogenic milieu (TM) identified with transesophageal echocardiography (TEE) in non-valvular atrial fibrillation (NVAF) patients with low to moderate thromboembolic (TE) risk.

METHODS

We retrospectively analyzed the baseline clinical data and TEE findings in 391 NVAF patients (54.7 ± 8.9 years, 69.1% male) with low to moderate TE risk according to the CHA₂DS₂-VASc score. LAA TM was defined as LAA thrombus (LAAT), sludge or spontaneous echo contrast (SEC). Management of LAA TM was at the discretion of the treating physician.

RESULTS

A total of 43 patients (11.0%) were detected with LAA TM, including 5 with LAAT (11.6%), 4 with LAAT + Sect. (9.3%), 3 with sludge (7.0%), and 31 with Sect. (72.1%). In multivariate model, non-paroxysmal AF (OR 3.121; 95% CI 1.205-8.083, p = 0.019), and a larger left atrial diameter (LAD) (OR 1.134; 95% CI 1.060-1.213, p < 0.001) were significantly associated with the presence of LAA TM. All LAATs or sludges effectively resolved after mean duration of 117.5 ± 20.0 days for oral anticoagulant (OAC) medication. TE events occurred in 3 patients (18.8%) among those discontinuing OAC over a mean follow-up of 26.2 ± 8.8 months, while no TE events occurred in patients with continuous OAC.

CONCLUSIONS

LAA TM could be identified in 11.0% in NVAF patients with low to moderate TE risk, especially in those with non-paroxysmal AF and enlarged LAD. Short-term OAC medication could effectively resolve the LAAT or sludge.

Global thrombosis test for assessing thrombotic status and efficacy of antithrombotic diet and other conditions

Because of the high mortality from myocardial infarction and stroke, there is a great demand for finding novel methods of diagnosis, prevention and treatment of these diseases. Most of the current tests measure important determinants of thrombosis such as platelet function, coagulation and fibrinolysis in isolation; therefore, a global test measuring the actual thrombotic status would be more useful in clinical conditions. We obtained considerable experience by using the global thrombosis test, which determines the actual thrombotic status by taking into account the measured platelet reactivity, coagulation and fibrinolytic activities. In animal experiments, we found significant correlation between the ex vivo global thrombosis test measurements and the in vivo thrombotic status. The published evidence for the benefit of an antithrombotic diet with regular physical exercise is also described.

There is a great concern in the general population how to detect the risk of thrombotic events and prevent the high mortality from stroke, myocardial infarction, sudden death and cancer-associated thrombosis. Our experience on antithrombotic fruits and vegetables intake and regular exercise assessed by the global thrombosis test suggested a potentially unique way of preventing these life-threatening diseases. In addition, global thrombosis testing may offer some benefit in detecting risk of thrombotic of forthcoming thrombotic events in cancer and COVID-19 virus-infected patients.

Are all wines made from various grape varieties beneficial in the prevention of myocardial infarction and stroke?

Aim:

Epidemiologic studies support the assumption (French paradox hypothesis) that drinking red wine is beneficial in the prevention of cardiovascular diseases. Our recent works however cast doubt on such claim. Earlier we have shown that the antithrombotic activity of various fruits and vegetables mainly depends on their varieties. For this reason, several varieties of red and white grapes were tested for antithrombotic effect in animal experiments.

Results:

Antithrombotic effect of 45 red and white grape varieties were assessed in the present study. Out of the 45, one red grape variety showed antithrombotic effect, while the majority of red and white grape varieties enhanced thrombosis.

Conclusion:

Most red and white grape varieties enhanced thrombotic activity of blood.

Red wine is widely believed to prevent heart attack and stroke as claimed by a French Paradox hypothesis. Antithrombotic effect of 45 grape varieties was measured in the present study. Only very few red and white varieties inhibited the experimentally induced thrombosis while the majority of the tested varieties enhanced thrombotic activity of blood. Thus, our findings challenge the prevailing claims of the French Paradox.

Efficacy and Safety of Direct Oral Anticoagulants in Patients with Atrial Fibrillation and Liver Disease: a Meta-Analysis and Systematic Review

BACKGROUND

Liver disease is associated with increased bleeding risk. The efficacy and safety of direct oral anticoagulants (DOACs) is a subject of contention in atrial fibrillation (AF) patients with liver disease.

METHODS

Electronic databases (PubMed, Embase, and Cochrane Library) were searched to retrieve studies on the efficacy and safety of DOACs versus warfarin in AF patients with liver disease from January 1980 to April 2020. A meta-analysis was conducted using a random-effects model.

RESULTS

Six studies involving 41,859 patients were included. Compared with warfarin, DOACs demonstrated significant reduction in ischemic stroke (HR, 0.68; 95% CI (0.54-0.86)), major bleeding (0.74 (0.59-0.92)), and intracranial hemorrhage (ICH) (0.48 (0.40-0.58)), with no significant effect on gastrointestinal bleeding (P = 0.893) in AF patients with liver disease. Similar results were observed in regular-dose, reduced-dose, and active liver disease subgroups, albeit Asian patients had a slight reduction in major bleeding (P = 0.055). Furthermore, the pooled estimates of individual DOAC subgroups indicated that dabigatran and apixaban led to greater safety in major bleeding (P < 0.001), ICH (P < 0.001), and gastrointestinal bleeding (P < 0.005) in these patients. The same trends were observed in AF patients with cirrhosis.

CONCLUSIONS

Our findings suggest that DOACs significantly reduce the risk of ischemic stroke, major bleeding, and ICH, with no significant effect on the risk of gastrointestinal bleeding in AF patients with liver disease compared with warfarin.