Conference News Update—ESC Congress 2014
To address this question, the researchers pooled data from two previously conducted clinical trials, ACTIVE-A and AVERROES, for a combined sample size of more than 6,000 patients with AF. Besides the large number of patients, another important strength of the analysis was that none of the patients were treated with anticoagulant medication, which reduces the risk of stroke. In contrast to population studies, in which it can be difficult to detect and verify all strokes, all events in the trial were rigorously detected and adjudicated.
The researchers found that patients with permanent AF had an almost twofold higher risk of stroke, compared with patients with paroxysmal AF. The yearly rate of stroke was 4.2% for patients with permanent AF, compared with 2.1% for patients with paroxysmal AF.
“Other studies have shown that patients with permanent AF are often younger and at a lower risk of stroke, compared to those with permanent AF, and these findings were confirmed in our analysis,” said Dr. Vanassche. “Nevertheless, the difference in risk of stroke remained significant when correcting for other risk factors such as age, heart failure, diabetes, sex, prior stroke, hypertension, and peripheral artery disease.
“The higher risk of permanent versus paroxysmal AF was also seen when considering patients with low, intermediate, or high risk of stroke separately,” he added. “It is very important to acknowledge that, regardless of its form and presentation, AF increased the risk of stroke. Therefore, all patients with AF should be assessed for risk, and if the risk is sufficiently high, they should be treated with anticoagulants. Thus, our results strengthen the existing recommendations.”
ROCKET AF Trial Suggests That Digoxin Increases Risk of Death in Patients With Atrial Fibrillation
Digoxin may increase the risk of death in patients with atrial fibrillation (AF) by approximately 20%, according to results from the ROCKET AF trial. The findings suggest that caution may be needed when using digoxin in patients with complex AF, but further studies are needed to confirm the observations.
“In this subanalysis of the ROCKET AF trial, we found that AF patients who took the drug digoxin had an increased risk of adverse cardiovascular events, including vascular death or sudden death,” said Manesh Patel, MD, Director of Interventional Cardiology and Catheterization Laboratories at Duke University Health System in Durham, North Carolina.
“Digoxin, which works to strengthen heart contractions, is one of the oldest medications used in the treatment of patients with heart failure and it has also been used in patients who have AF,” he added. “However, the use of digoxin in AF patients has not been rigorously studied in randomized trials. We therefore conducted a retrospective subanalysis of the ROCKET AF trial to determine the effect of digoxin on the risk of death in patients with AF.”
ROCKET AF was a double-blind trial conducted in 14,171 patients with nonvalvular AF who were at increased risk of stroke. The study took place at 1,178 sites in 45 countries. Patients were randomized to take either rivaroxaban or warfarin for anticoagulation. The investigators found that in patients with AF, rivaroxaban was not inferior to warfarin for the prevention of stroke or systemic embolism.
In the current analysis, the researchers examined the risks of all-cause mortality and cardiovascular mortality in 5,239 patients taking digoxin at the start of the study, compared with 8,932 patients who were not taking digoxin. The researchers found that digoxin was associated with a 22% increased risk of death resulting from any cause and a 22% increased risk of death resulting from a cardiovascular event.
“Our analysis represents an important observation with digoxin use in patients with atrial fibrillation,” said Dr. Patel. “Digoxin could potentially be harmful, and we need randomized trials to determine whether it can be used in patients with atrial fibrillation. Our findings suggest that doctors should proceed with caution when using this drug for complex AF patients.”
“Despite [it] being one of the oldest therapeutics in heart care, we still know very little regarding the risks and benefits of digoxin when used in patients with AF,” said Jeffrey Washam, a clinical pharmacist at the Duke Heart Center in Durham, North Carolina. “In complex patients with AF, this analysis highlights the need for well-controlled studies to evaluate the efficacy and safety of digoxin.”
“The results from this study should be confirmed in a prospective randomized trial,” concluded Dr. Patel.
Resistant Hypertension Increases Stroke Risk in Women and Elderly Taiwanese
Resistant hypertension increases the risk of stroke by 35% in women and 20% in elderly Taiwanese patients, according to research presented. The findings suggest that gender and age should be added to the risk stratification of resistant hypertension to enable more appropriate treatment decisions.
