Significant 30 Percent Increase in Relative Risk of Cardiovascular Events or Death

PfizerAn observational study of a large United Kingdom primary care database showed that switching patients from Pfizer's Lipitor® (atorvastatin calcium) Tablets to simvastatin was associated with a 30 percent increase in the relative risk of major cardiovascular events, including heart attacks, strokes and certain types of heart surgeries, or death compared to patients who remained on Lipitor therapy.

This analysis was presented today at the European Society of Cardiology Congress 2007 and is also in press at The British Journal of Cardiology.

The data, which included records from October 1997 to June 2005, were generated from a retrospective analysis of a medical database of anonymous patient records entered by general practitioners in the United Kingdom known as The Health Improvement Network (THIN). The analysis included 11,520 patients (2,511 patients who had taken Lipitor for six months or more and were switched to simvastatin vs. 9,009 patients who were taking Lipitor for six months or more and then remained on Lipitor therapy). Reasons for switching were not available from the database. Since patients were not randomly assigned to each group, the two treatment groups were matched based on certain risk factors and statistical adjustments were made to address any residual imbalances. As with all observational studies, the findings should be regarded as hypothesis generating.

"Today, many health care payors including governments and managed care companies are encouraging patients who are well-established on one therapy to switch to a different statin therapy," said Dr. Michael Berelowitz, senior vice president of Pfizer’s global medical division. "This study raises concerns about those policies. It suggests the potential for poorer cardiovascular outcomes associated with switching patients from established Lipitor therapy to simvastatin."

A secondary analysis of the same data showed that patients who were switched from Lipitor to simvastatin were more than twice as likely to discontinue their treatment compared to those who remained on Lipitor therapy (20.5 percent versus 7.62 percent, p<0.001). The reasons for discontinuation were not available from the database, though disruption in treatment has been associated with poor adherence in previous studies of statins and other medications.

"The results of this analysis complement the large body of evidence from multiple clinical trials demonstrating the cardiovascular benefits of Lipitor," said Dr. Berelowitz. "Observational studies help the medical community better appreciate what is really happening in doctors' offices, and are commonly used by healthcare payors to set medical practice guidelines. This analysis highlights the need to carefully consider individual patient circumstances and cardiovascular risk because indiscriminate switching may adversely affect some patients."

Additional Study Information The primary endpoint was time to a first major cardiovascular event, defined as heart attack, stroke, or coronary revascularization (a type of heart surgery), or all-cause death. There was a statistically significant 30 percent increase in the relative risk of the primary endpoint (p=0.03).

  • The individual components making up the primary endpoint were analyzed as secondary endpoints. Compared with patients who did not switch therapy, switching was associated with the following:
    • Significant 43 percent increase in the relative risk of major cardiovascular events (p=0.008)
    • No difference in all-cause death (p=0.369)
  • The two treatment groups were matched based on the following: gender, history of heart attack, diabetes, time since last statin exposure and general practitioner treatment center.
  • The following statistical adjustments were made to address any residual imbalances: age, gender, prior statin exposure, time since last statin exposure, diabetes, history of heart attack, and baseline cholesterol levels.
  • Relative risk is the ratio of the risk of major cardiovascular events or death occurring in the group who switched from Lipitor to simvastatin versus the risk in the group who remained on Lipitor.

About Lipitor
Lipitor is the only statin with all the following criteria most important for many physicians, patients and payors: significant and proven cardiovascular event reductions, impressive average LDL lowering of 39 percent to 60 percent, and a proven safety profile across a broad range of patients.

Lipitor is the most prescribed cholesterol-lowering therapy in the world, with nearly 139 million patient-years of experience. It is supported by an extensive clinical trial program involving more than 400 ongoing and completed trials with more than 80,000 patients. There have been more than ten cardiovascular outcomes trials with more then 50,000 patients.

For further information, please visit:
http://www.pfizer.com

Most Popular Now

Sustained cellular immune dysregulation in individ…

COVID-19, which has killed 1.7 million people worldwide, does not follow a uniform path. Many infected patients remain asymptomatic or have mild symptoms. Others, espe...

New virtual screening strategy identifies existing…

A novel computational drug screening strategy combined with lab experiments suggest that pralatrexate, a chemotherapy medication originally developed to treat lymphoma, c...

An in vitro study shows Pfizer-BioNTech COVID-19 v…

Pfizer Inc. (NYSE: PFE) and BioNTech SE (Nasdaq: BNTX) today announced results from an in vitro study conducted by Pfizer and the University of Texas Medical Branch (UTMB...

European Commission authorizes COVID-19 vaccine Mo…

Moderna, Inc. (Nasdaq: MRNA), a biotechnology company pioneering messenger RNA (mRNA) therapeutics and vaccines, announced that the European Commission has granted a cond...

Serum Institute of India obtains emergency use aut…

AstraZeneca's COVID-19 vaccine has been granted emergency use authorisation in India as well as Argentina, Dominican Republic, El Salvador, Mexico and Morocco for the act...

CureVac and Bayer join forces on COVID-19 vaccine …

Bayer has signed a collaboration and services agreement with CureVac N.V. (Nasdaq: CVAC), a biopharmaceutical company developing a new class of transformative medicines b...

New findings help explain how COVID-19 overpowers …

Seeking to understand why COVID-19 is able to suppress the body's immune response, new research from the USC Leonard Davis School of Gerontology suggests that mitochondri...

Valneva in advanced discussions with European Comm…

Valneva SE, a specialty vaccine company focused on prevention of infectious diseases with significant unmet medical need, announced it is in advanced discussions with the...

China grants conditional market approval for Sinop…

The inactivated COVID-19 vaccine developed by Beijing Institute of Biological Products of Sinopharm CNBG has been granted conditional registration by the NMPA of China, C...

Scientists identify 'immune cop' that detects SARS…

Scientists at Sanford Burnham Prebys Medical Discovery Institute have identified the sensor in human lungs that detects SARS-CoV-2 and signals that it's time to mount an ...

Novavax announces initiation of PREVENT-19 pivotal…

Novavax, Inc. (Nasdaq: NVAX), a late-stage biotechnology company developing next-generation vaccines for serious infectious diseases, today announced initiation of PREVEN...

AstraZeneca's COVID-19 vaccine authorised for emer…

AstraZeneca's COVID-19 vaccine has been approved for emergency supply in the UK, with the first doses being released today so that vaccinations may begin early in the New...