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 Once invincible superbug squashed by 'superteam' of antibiotics
22.08.2017 | University at Buffalo

nachricht Chronic stress induces fatal organ dysfunctions via a new neural circuit
21.08.2017 | Hokkaido University

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Molecular volume control

22.08.2017 | Life Sciences

When fish swim in the holodeck

22.08.2017 | Life Sciences

Biochemical 'fingerprints' reveal diabetes progression

22.08.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>