Dramatic decline in risk for heart attacks among HIV-positive Kaiser Permanente members

Previously reported increased risk of heart attacks among HIV-positive individuals has been largely reversed in recent years for Kaiser Permanente's California patients, according to a study published in the current online issue of Clinical Infectious Diseases.

"Our findings lend support to the concept that increased heart attack risk for HIV patients is largely reversible with continued emphasis on primary prevention in combination with early initiation of anti-retroviral therapy to preserve immune function," said lead author Daniel B. Klein, MD, Chief of Infectious Diseases for Kaiser Permanente San Leandro.

The adjusted risk ratio for heart attacks among HIV-positive study participants went from an 80 percent increased risk in 1996 to no increased risk in 2010-2011. The study population included 24,768 HIV-positive and 257,600 demographically matched HIV-negative subjects from Kaiser Permanente Northern California and Kaiser Permanente Southern California.

Noting that the study participants are members of a large integrated health care setting, the investigators say these results may be explained by access to care and broadly disseminated cardiovascular risk reduction efforts. These include the implementation of health prompts that appear during all clinic visits in the electronic medical record with reminders for cholesterol and blood pressure monitoring, diabetes follow-up, and smoking cessation.

One of the first reports documenting an increased risk of cardiovascular disease was conducted among Kaiser Permanente HIV patients and led by Dr. Klein. That early awareness within the Kaiser Permanente health care system may have resulted in enhanced attention to cardiovascular risk reduction and interventions in this population. Over the 16-year study period, HIV-positive subjects had similar increases in the use of lipid-lowering and hypertension therapy compared with HIV-negative subjects.

In addition, in accordance with national treatment guidelines mirrored within Kaiser Permanente, patients are being started on antiretroviral treatments earlier and being prescribed less toxic combination therapies.

"Such early and sustained improvements in care would have been necessary to achieve not only a reduction in risk of heart attack but a virtual leveling of risk between HIV-positive and HIV-negative individuals," said senior author Michael J. Silverberg, PhD, MPH, a senior research scientist with the Kaiser Permanente Division of Research. "The takeaway from this study is that the well-established higher risk of a heart attack in HIV patients may be reversible. With better HIV treatments, and more attention to traditional cardiovascular risk factors, the difference in risk by HIV status has been diminished or even eliminated."

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Other authors on the study include Wendy A. Leyden, MPH, Leo B. Hurley, MPH, Julia L. Marcus, PhD, MPH, Charles P. Quesenberry, Jr, PhD, Division of Research, Kaiser Permanente Northern California, Oakland, California; Lanfang Xu, MS, and Chun R. Chao, PhD, Department of Research and Evaluation, Kaiser Permanente, Pasadena, California; Michael A. Horberg, MD, MAS, Mid-Atlantic Permanente Research Institute, Rockville, Maryland; and William J. Towner, MD, Division of Infectious Diseases, Department of Internal Medicine, Kaiser Permanente Los Angeles.