Long-term Warfarin use may increase dementia rates in AF patients

In continuation of  Warfarin

A new study of more than 10,000 patients treated long term with the blood thinner, Warfarin, reveals higher rates of dementia for patients with atrial fibrillation versus non-AF patients.

The study by researchers at the Intermountain Medical Center Heart Institute in Salt Lake City found that atrial fibrillation patients treated long term with Warfarin had higher rates of dementia, Alzheimer's disease and vascular dementia compared to anticoagulated non-atrial fibrillation patients.

Results of the research were presented today at Heart Rhythm 2016, the Heart Rhythm Society's 37th Annual Scientific Sessions in San Francisco.

Atrial fibrillation is is the most common type of arrhythmia, which is a problem with the rate or rhythm of the heartbeat. During an arrhythmia, the heart can beat too fast, too slow, or with an irregular rhythm. Incidence rates of atrial fibrillation are growing dramatically as the population ages.

Dementia is a neurological disorder that impairs memory and other cognitive abilities, and it is now listed among the leading causes of morbidity and mortality in developed countries.

Atrial fibrillation can increase the risk of dementia because it exposes patients to both large and small clots that can affect brain function. Blood thinners used to prevent all forms of clots and strokes can increase the risk of both large and small brain bleeds that can also negatively impact brain function over time.

The study was conducted through the Intermountain Healthcare Clinical Pharmacist Anticoagulation Service, which is part of the Intermountain Healthcare system based in Salt Lake City.

Researchers enrolled a total of 10,537 patients with no history of dementia prior to the study. They were treated with a blood thinner for atrial fibrillation and non-AF conditions like valvular heart disease and thromboembolism on a long-term basis.

Other variables in the patients studied included age, hypertension, diabetes, hyperlipidemia, renal failure, smoking history, prior myocardial infarction or cerebral vascular accident, and heart failure. Participants were aged 18 years and older.

New Anti-Clotting Drug May Cut Brain Bleeding Risk: Study

In continuation of my update on rivaroxaban (Xarelto)

In a new study, researchers led by Dr. Graeme Hankey, a neurologist at the Royal Perth Hospital and University of Western Australia, followed more than 14,000 people who took anti-clotting drugs for a median of two years. Of those patients, 136 had bleeding in the brain.

People who took a new anticoagulant called rivaroxaban (Xarelto) and suffered from the most common type of atrial fibrillation and didn't have heart valve damage were about one-third less likely to experience bleeding in the brain than those who took warfarin, the investigators found...

More...

Dabigatran, New Blood Thinner Linked To Higher Heart Attack Risk

In continuation of my update on Dabigatran...

Researchers lead by Dr.Ken Uchino from the Cleveland Clinic in Ohio looked at seven trials involving Pradaxa (Dabigatran) that included more than 30,000 patients. This process, called a meta-analysis, uses data from published clinical trials to tease out a pattern that might not show up in a single study. Researchers found Pradaxa was associated with an increased risk of heart attack or acute coronary syndrome (heart attack or angina), compared with two other commonly used blood thinners, warfarin (Coumadin, Jantoven) and enoxaparin (Lovenox).

As per the claim by the researchers,  those taking Pradaxa, 1.19 percent had a heart attack or suffered from acute coronary syndrome compared with 0.79 percent of those taking either of the other drugs, they noted. Although there was a 33 percent increase in relative risk for a heart attack among those taking Pradaxa, the absolute increased risk -- that is, the added risk for any one individual of having a heart attack if on Pradaxa -- was 0.27 percent, researchers said.

Pradaxa was approved by the U.S. Food and Drug Administration in October 2010 for people with a common heart rhythm problem called atrial fibrillation. People with atrial fibrillation are at a higher risk for stroke and are often prescribed medication to prevent clotting....

Ref : http://my.clevelandclinic.org/cerebrovascular_center/medical_professionals/clinical_trials.aspx

Study Pits New Blood Thinner Against Warfarin For Irregular Heartbeat

A new drug, Rivaroxaban, (see structure) that lowers stroke risk among people with an irregular heartbeat may give the old standby, warfarin, some competition, a new study shows.

 We know that, Rivaroxaban (BAY 59-7939) is an oral anticoagulant invented and manufactured by Bayer; in a number of countries it is marketed as Xarelto. In the United States, it is marketed by Janssen Pharmaceutica. It is the first available orally active direct factor Xa inhibitor. Rivaroxaban is well absorbed from the gut and maximum inhibition of factor Xa occurs four hours after a dose. The effects lasts 8–12 hours, but factor Xa activity does not return to normal within 24 hours so once-daily dosing is possible. Now the  new trial pitted the newer drug, rivaroxaban, against warfarin in more than 14,000 patients who were randomly assigned either warfarin or rivaroxaban. Neither the patients nor the doctors knew who was taking which drug. As per the claim by the resarchers, new agent proved to be as effective as warfarin at reducing the risk of ischemic stroke -- the most common kind of stroke,  but it did not need to be monitored as closely as warfarin since it is given as a one-size-fits-all dose....

"a reasonable alternative to warfarin, with less intracranial or fatal bleeding." claims the lead researcher, Dr. Manesh R. Patel...

Ref : http://www.newsroom.heart.org/index.php?s=43&item=1191

Dabigatran etexilate a better drug than warfarin for VTE?.

We know that Dabigatran is an anticoagulant from the class of the direct thrombin inhibitors. It is being studied for various clinical indications and may replace warfarin as the preferred anticoagulant in many cases. It is orally administered as the prodrug dabigatran etexilate (marketed as Pradaxa since April 2008 in European countries and Pradax in Canada). It was developed by the pharmaceutical company Boehringer Ingelheim.

Now researchers lead by  Dr. Sam Schulman, a professor of medicine of the Michael G. DeGroote School of Medicine (McMaster University), who conducted a randomized, double-blind trial of 2,539 patients with acute VTE (venous thromboembolism) have found that dabigatran (see structure) is a safe and effective anticoagulant that does not require the routine monitoring or dose adjustments that are necessary with warfarin. In other words, patients can receive the same results in a more convenient manner. 

As per the claim by the researchers, the improvement seen in both groups from the treatments was similar. After six months of treatment, only 2.4 percent of the dabigatran etexilate group (30 patients) and 2.1 percent of the warfarin group (27 patients) experienced recurrent VTE. The safety of the two drugs was also comparable. In the dabigatran etexilate arm, 205 patients experienced bleeding (including 20 patients with major bleeding) versus 277 patients in the warfarin arm (including 24 with major bleeding). Other possible side effects, including death, acute coronary syndromes, and abnormalities in liver function tests, were infrequent in the two groups. Hope patients suffering from VTE will now breathe a sigh of relief....

Ref : http://dailynews.mcmaster.ca/story.cfm?id=6511