Raised Blood Pressure/BMI in Midlife Predicts Heart Failure in Later Life

Raised blood pressure (BP) and excess body mass index (BMI) in middle age increases the risk of heart failure in later life, a new study suggests.

Dr Douglas Lee (University of Toronto, ON), conducted the study and concluded that their data, although observational, suggest that effective heart-failure prevention strategies are best conceived as lifelong initiatives, rather than as beginning in the seventh decade, at which point the risk of developing the condition begins to escalate.

Lee et al note that the incidence of heart failure increases exponentially in the seventh decade of life and beyond and is therefore often regarded as a disease of the elderly. Given the substantial adverse outcomes associated with heart failure, disease-management guidelines have emphasized the importance of prevention, but that the development of preventive strategies requires a better understanding of the key risk factors for heart failure and the evolution of these risk factors over the life course, they add.

They point out that although previous studies have greatly advanced the understanding of risk factors for heart failure, they have not evaluated the contribution of potential risk factors at an earlier point in the life course, such as in midlife. As it is widely accepted that cardiac remodeling evolves over time and, in response to risk factor exposures, Lee and colleagues used Framingham data to examine whether BP and BMI measures obtained over a period of two decades in the midlife period of study participants were related to the risk of heart failure during follow-up.

They studied 3362 Framingham participants (57% women; mean age 62 years) who attended routine examinations between 1969 and 1994 and examined their systolic and diastolic BP, pulse pressure, and BMI at various time periods during the past 20 years.

Results showed that during 67,240 person-years of follow-up, 518 participants developed heart failure. Current, recent, and remote systolic pressure; pulse pressure; and BMI were all individually associated with incident heart failure. The recent and remote associations remained after adjusting for current measurements.

Associations of Antecedent Blood Pressure With Incident Heart Failure

Blood pressure	HR (95% confidence interval [CI]) for congestive heart failure (CHF) per standard deviation (SD) increment of BP measure (adjusted for current BP)
Recent (1 – 10 yrs prebaseline)
Systolic	1.31 (1.11 – 1.55)
Diastolic	1.02 (0.88 – 1.19)
Pulse	1.33 (1.14 – 1.54)
Remote (11 – 20 yrs prebaseline)
Systolic	1.17 (1.04 – 1.31)
Diastolic	1.05 (0.93 – 1.18)
Pulse	1.17 (1.06 – 1.31)

Results are age-stratified and adjusted for age, sex, serum cholesterol, hypertension treatment, diabetes, smoking, valve disease, and previous myocardial infarction (MI; all defined at the baseline examination) and for the incidence of an interim MI on follow-up. Models evaluating systolic BP variables are adjusted for baseline diastolic BP. Models evaluating diastolic BP variables are adjusted for baseline systolic BP.

Associations of Antecedent BMI With Incident Heart Failure

BMI	HR (95% CI) for congestive heart failure (CHF) per unit increment of BMI (adjusted for current BMI)
Recent (1 – 10 yrs prebaseline)	1.15 (1.08 – 1.23)
Remote (11 – 20 yrs prebaseline)	1.09 (1.05 – 1.14)

Lee et al say that although hypertension and high BMI detected in later life are associated with heart failure risk, the effects of these conditions likely begin much earlier. "High blood pressure and elevated BMI in midlife or earlier life may contribute to progressive remodeling of the heart and vasculature, which may predispose to heart failure decades later. Therefore, the prevention of heart failure should begin early in the life course and should include screening for elevated blood pressure and BMI," they write. "Failure to identify or treat such modifiable risk factors early may result in the loss of opportunities to reduce the incidence of heart failure in later life," they add.

Commenting on the study senior author, Dr Ramachandran Vasan (Boston University School of Medicine) noted that an increase of just one standard deviation (about 20 mm Hg) in systolic blood pressure at age 50 was associated with a 36% higher risk of heart failure over an observation period extending up to 20 years later, and a standard deviation ((about 15 mm Hg) increase in pulse pressure increased the heart failure risk by 31%. "Every 1 kg/m2 increment in current, recent or remote BMI was associated with a 5% to 7% increase in the risk of heart failure," Vasan said. "This study highlights the importance of maintaining an ideal BMI and blood pressure over the life course of individuals," he concluded.

Practice Pearls

• The prevention of heart failure should begin early and should include regular, periodic BP checks and screening for obesity beginning in early adulthood and behavior modification to reduce elevated BMI.
• Higher BP and BMI exert adverse effects with time, and the presence of these risk factors increases the risk for incident heart failure later in life.

Hypertension online,  September 24, 2007, Lee DS, Massaro JM, Wang TJ, et al. Antecedent blood pressure, body mass index, and the risk of incident heart failure in later life.