Study Findings on LDL Cholesterol

Findings of historical studies have suggested that elevated LDL cholesterol is not associated with increased risk of myocardial infarction (MI) and atherosclerotic cardiovascular disease (ASCVD) in patients older than 70 years. But in a recently published study from The Lancet, adults aged 70-100 years with elevated LDL cholesterol had in fact the highest absolute risk of MI and ASCVD. This underscores the potential benefit of statins in this subgroup.

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91,131 individuals aged 20–100 years from the Copenhagen General Population Study (CGPS) who did not have ASCVD or diabetes at baseline and who were not taking statins were included in this study published in November edition of The Lancet. Hazard ratios (HRs) and absolute event rates for MI and ASCVD were calculated, and the number needed to treat (NNT) in 5 years to prevent one event was estimated.

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Following results were derived over an average of 7.7 years of follow-up:

• 1,515 individuals had a first MI, and 3,389 had ASCVD. The highest event rates were observed in those aged 80-100.
• Each 1.0 mmol/L increase in LDL cholesterol was associated with an increased risk for MI in the total population (HR=1.34), but highest for those aged 70-100 years.
• A similar association was seen for ASCVD risk, particularly those aged 70-100 years.
• Among those with significantly elevated LDL (≥5.0 mmol/L LDL cholesterol) versus <3.0 mmol/L (<116 mg/dl), risk for MI was significant, including for those aged 80-100 years (HR, 2.99) and in those aged 70-79 years (HR, 1.82).
• MI and ASCVD events per 1,000 person-years for every 1.0 mmol/L increase in LDL cholesterol were highest in individuals aged 70-100 years, with the number of events lower with younger age.
• The number needed to treat (NNT) in 5 years to prevent one MI or ASCVD event if all people were given a moderate-intensity statin was lowest for individuals aged 70-100 years, with the NNT increasing with younger age.

Concluding the findings from this contemporary primary prevention cohort, elderly people with elevated LDL cholesterol had the highest absolute risk of MI and ASCVD and the lowest estimated NNT in 5 years to prevent one event. This study is important for preventive strategies aimed at reducing the burden of cardiovascular diseases in the elderly and contradicts the previous studies that had side-lined the significance of LDL-cholesterol control in this population.

Source: Elevated LDL Cholesterol and Increased Risk of Myocardial Infarction and Atherosclerotic Cardiovascular Disease in Individuals Aged 70–100 Years: A Contemporary Primary Prevention Cohort. Lancet 2020; 396:1644-1652.

The article can be viewed from: The Lancet