Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Two drugs are better than one to prevent return of atrial fibrillation

25.06.2002


The high blood pressure drug irbesartan delayed the recurrence of irregular heartbeats, researchers report for first time in today’s rapid access issue of Circulation: Journal of the American Heart Association.



The drug helped stop irregular heartbeats (arrhythmias) known as atrial fibrillation (AF). AF is a disorder in which the two small, upper chambers of the heart quiver instead of beating effectively. Blood that isn’t pumped out may pool and clot. If a piece of clot leaves the heart and lodges in an artery to the brain, a stroke results.

Irbesartan is in a class of drugs called angiotensin II antagonists, or blockers. They are used to treat several cardiovascular disorders such as high blood pressure and heart failure.


AF is considered the most common sustained heart arrhythmia, and its incidence rises with age to about 10 percent in people over age 75, says study author Concepción Moro, M.D., professor of medicine at the University of Alcala and director of the arrhythmia unit at the Ramon y Cajal hospital in Madrid, Spain.

"AF is believed to double the risk of death and quadruple the risk of strokes," she says. "In addition, AF may accompany many cardiac conditions such as valvular heart disease, cardiomyopathies and ischemic heart disease. It can also appear along with high blood pressure and other systemic diseases such as hyperthyroidism, although in many patients the cause is unknown."

AF is typically treated with antiarrhythmic drugs such as amiodarone, anti-clotting agents, and electrical cardioversion, a procedure that uses an electrical impulse to destroy areas of heart tissue where the rhythm disturbances originate. However, AF often recurs despite these treatments, so new options are needed, Moro says.

"The clue for this work was evidence that patients treated with angiotensin II antagonists for other conditions developed fewer atrial arrhythmias than expected," she explains.

In the study, 154 patients who had continuous AF for more than seven days were randomly assigned into two groups to receive one of two treatments. Group I got amiodarone, while group II received amiodarone plus irbesartan. All of the patients were scheduled to have electrical cardioversion three weeks after beginning therapy.

At the three-week point, 62 patients had stable heart rhythms on medication alone and 92 went on to have electrical cardioversion, 83 of them successfully. During the next two months, 26 patients had a recurrence of AF. An analysis found the two-month probability of maintaining a stable heartbeat was nearly 85 percent for subjects who got irbesartan compared to 63 percent for those who did not.

"Our analysis revealed that using the angiotensin II receptor antagonist was the only significant variable related to maintaining heart rhythm after cardioversion," the researchers write.

Patients treated with irbesartan had a greater probability of remaining free of AF than those treated with amiodarone alone (80 percent vs. 56 percent). One of the most important factors to predict recurrence was the duration of AF before randomization.

"There were a very low number of adverse events, well within the expected limits, and the incidence rate was similar in both groups," Moro notes.

One 51-year-old man in group II suffered sudden death three weeks after his successful cardioversion procedure, but his death was not believed to be related to the procedure because of the time lag, she says. In addition, three patients in group I and two in group II had adverse events that required therapy to be discontinued.


Lead author of the study was Antonio Hernandez-Madrid, M.D. Other co-authors were Manuel G. Bueno, M.D.; Jose M.G. Rebollo, M.D.; Irene Marín, M.D.; Gonzalo Peña, M.D.; Enrique Bernal, M.D.; Aníbal Rodriguez, M.D.; Lucas Cano, M.D.; José M. Cano, M.D.; and Pedro Cabeza, M.D.

This work was supported in part by a grant from the Ministry of Health of Spain and by a grant from the drug company Sanofi-Synthelabo.

CONTACT: For journal copies only,
please call: (214) 706-1396
For other information, call:
Bridgette McNeill: (214) 706-1135
Maggie Francis (214) 706-1397


Maggie Francis | EurekAlert!

More articles from Health and Medicine:

nachricht 3D images of cancer cells in the body: Medical physicists from Halle present new method
16.05.2018 | Martin-Luther-Universität Halle-Wittenberg

nachricht Better equipped in the fight against lung cancer
16.05.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

Im Focus: Computer-Designed Customized Regenerative Heart Valves

Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.

Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...

Im Focus: Light-induced superconductivity under high pressure

A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.

Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Supersonic waves may help electronics beat the heat

18.05.2018 | Power and Electrical Engineering

Keeping a Close Eye on Ice Loss

18.05.2018 | Information Technology

CrowdWater: An App for Flood Research

18.05.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>