Largest Atrial Fibrillation Registry Reveals Poor AF Control and High Rates of Cardiovascular Hospitalization

Over 10,000 Patients Included in RealiseAF

PARIS, September 1, 2010 - Sanofi-aventis (EURONEXT: SAN and NYSE: SNY) announced today
that results from the RealiseAF (Real-life global survey evaluating patients
with Atrial Fibrillation) registry show that control of atrial fibrillation
(AF) (defined by the 2006 ACC/AHA/ESC AF guidelines as either sinus rhythm or
AF with heart rate at rest less than or equal 80 bpm)[1] was not achieved in
more than 40 percent of the AF patients included in this 10,000 patient
cross-sectional registry, as presented today during the European Society of
Cardiology Congress in Stockholm, Sweden. In addition, the registry revealed
that a majority of patients complain of symptoms, even when AF is controlled
[2] (55.7 percent).

Importantly, cardiovascular (CV) events were very frequent in
this population, with a high rate of concomitant CV risk factors (72.2% of
patients were hypertensive and 46.3% of patients had dyslipidemia) 28.7
percent of AF patients suffered from CV events such as acute coronary
syndrome (ACS) acute heart failure or stroke, leading to an unplanned
hospitalisation during the last 12 months and 12.4 percent of patients
requiring major CV interventions such as Percutaneous Coronary Intervention
(PCI), Coronary Artery Bypass Graft (CABG) or valvular surgery.

Management of AF in a real-life setting shows that today, AF
is not treated according to the 2006 ACC/AHA/ESC AF guidelines:

    - 20 percent of AF patients with structural heart disease
      received Class Ic AADs, despite its contraindication in this patient
      population.

    - 49.9 percent of evaluated paroxysmal and persistent AF
      patients without congestive heart failure (CHF) or hypertension with
      significant left ventricular hypertrophy received amiodarone as a
      first-line treatment, despite guidelines recommendations that it be
      used as a second line agent.

    - In addition, patients with a CHADS2 greater than or equal to
      2 who should receive anti-coagulants agents only received these agents
      in 52 percent of cases.

"The RealiseAF registry shows that patients suffering from
atrial fibrillation not only require symptom relief but management which goes
beyond heart rate or rhythm control, and addresses event-driven
hospitalisations," said Professor Ph. Gabriel Steg, Department of Cardiology,
Hôpital Bichat, Paris, France, on behalf of the RealiseAF steering committee.
"The data suggest a need for new therapies and an increased focus on
cardiovascular outcomes, as well as a more stringent adherence to
guidelines."

About RealiseAF

RealiseAF is a large international cross-sectional registry
established in 2009 to determine the rate of AF control and establish the
burden of cardiovascular (CV) disease in typical patients with AF.

RealiseAF is coordinated by an independent scientific
committee of international experts in cardiology and electrophysiology, and
uses a comprehensive data collection strategy. Building on the success of
previous registries, including RecordAF and the European Heart Survey on AF,
RealiseAF provides a reliable assessment of the CV risk profile of patients
with AF, the types of treatment they receive, and how these factors influence
outcomes in a real-world setting.

The registry was launched in November 2009 and the database
locked in June 2010. More than 10,000 patients from 26 countries were
enrolled. Participating countries included: Algeria, Azerbaijan, Belgium,
Bulgaria, Czech Republic, Egypt, Germany, Hungary, India, Ireland, Italy,
Lebanon, Lithuania, Mexico, Morocco, Portugal, Russia, Slovakia, Spain,
Sweden, Switzerland, Taiwan, Tunisia, Turkey, Ukraine and Venezuela.

The registry RealiseAF was sponsored by sanofi-aventis.

About atrial fibrillation

Atrial fibrillation affects close to 7 million people in the
USA and the EU alone. By 2050, the prevalence of AF in the USA is predicted
to more than double. As a growing international health concern, AF is
associated with an increase in morbidity and mortality, particularly due to
cardiovascular (CV) events leading to an increased risk of hospitalisation,
which contributes considerably to healthcare costs.

For more information, please visit: https://www.realiseaf.org.

About sanofi-aventis

Sanofi-aventis, a leading global pharmaceutical company,
discovers, develops and distributes therapeutic solutions to improve the
lives of everyone. Sanofi-aventis is listed in Paris (EURONEXT: SAN) and in
New York (NYSE: SNY).

1. Fuster V et al. ACC/AHA/ESC 2006 guidelines for the management of
patients with atrial fibrillation. European Heart Journal (2006) 27,
1979-2030.

2. Steg, P. "The REALISE-AF registry: an international, observational,
cross-sectional survey describing characteristics, cardiovascular risk, and
management of patients with atrial fibrillation." Presented at the European
Society of Cardiology Congress, Sept. 1, 2010. Program number 5080.
spo.escardio.org/SessionDetails.aspx?id=331012

Media Contact: Ingrid Görg-Armbrecht, +33-1-53-77-46-25 or +33-6-38-10-50-87, ingrid.goerg-armbrecht at sanofi-aventis.com .