Lifetime CVD risk affected by risk factor burden
MedWire News: An individual's lifetime risk for cardiovascular disease (CVD) is significantly affected by their risk factor burden, a meta-analysis shows.
These findings are consistent across Black patients and White patients, report Donald Lloyd-Jones (Northwestern University, Chicago, Illinois, USA) and co-authors in the New England Journal of Medicine.
They conducted a meta-analysis at the individual level using data from 18 cohort studies and a total of 257,384 Black participants and White participants. The risk factors for CVD, defined as diabetes, current smoking, mean total cholesterol, and mean systolic blood pressure (BP), of all participants were measured at the ages of 45, 55, 65, and 75 years.
Participant data were stratified according to risk factor levels or status as assessed within 5 years of each index age. For example, risk factors measured for participants between 40 and 49 years of age were included in the analysis for the age of 45 years.
Risk factor level or status was classified into five mutually exclusive categories: one in which all risk factors was optimal, at least one factor not optimal, one risk factor elevated, one major risk factor present, and a fifth in which two or more major risk factors were present.
Major risk factors were defined as current smoking, diabetes, treatment for hypercholesterolemia, untreated total cholesterol level of at least 6.21 mmol/L, treatment for hypertension, and untreated BP of at least 160 mmHg systolic or 100 mmHg diastolic.
The optimal risk factor patient profile was a nonsmoker without diabetes and with a total cholesterol level of 4.7 mmol/L or less, and untreated BP no higher than 120 mmHg systolic and 80 mmHg diastolic.
The findings revealed that there were marked differences in the lifetime risks for CVD across risk factor strata. Indeed, among participants who were 55 years of age, those with an optimal profile had a significantly lower risk for mortality through the age of 80 years than those with two or more major risk factors (4.7 vs 29.6% in men, 6.4 vs 20.5% in women).
Participants with an optimal risk factor profile also had significantly lower lifetime risks for fatal coronary heart disease or nonfatal myocardial infarction (3.6 vs 37.5% in men, <1 vs 18.3% in women), and fatal or nonfatal stroke (2.3 vs 8.3% in men, 5.3 vs 10.7% in women).
A comparison between Black and White participants of the same gender showed that the lifetime risks for CVD mortality were similar among participants with similar levels of aggregate risk. Indeed, analysis of the Multiple Risk Factor Intervention Cohort, which was the largest cohort in the study, demonstrated that at 55 years of age, both White men and Black men with optimal risk factor profiles had substantially lower lifetime risks for CVD than did men with two or more major risk factors (4.0 vs 26.6% in White men, 9.9 vs 27.9% in Black men).
The results of race-stratified analyses were similar among women.
"We believe these findings have important implications for clinical disease prevention and public health practice," comment the authors. "The present estimates of lifetime risk… may be important in estimating the future burden of CVD in the general population."
"Efforts to lower the burden of CVD will require prevention of the development of risk factors (primordial prevention) rather than the sole reliance on the treatment of existing risk factors (primary prevention)."
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By Piriya Mahendra