News · Heart & Metabolic
Stroke patients who hit the cholesterol target but had not halved it still had 12% more repeat events
Stroke guidelines set an absolute cholesterol target and stop there. A Neurology analysis of 89,414 Korean patients found the size of the fall from baseline mattered independently, and only about 30% achieved a 50% reduction.
- Stroke patients who hit the cholesterol target but had not halved it had 12% more repeat events.
- How far cholesterol fell from where it started mattered on top of the target itself.
- Only about 30% of patients ever managed a 50% reduction.
- People who met neither goal fared worst of all.
- 89,414 Korean patients followed almost six years, from records rather than a trial.
A cholesterol result at target looks like a finished job. This study says it can be two different things.
Consider two people leaving hospital after a stroke, both with an LDL cholesterol of 68. One started at 74 and has barely been treated. The other started at 170 and has had a large intervention. The number in the notes is the same. The arteries are not.
Writing in Neurology, Baik and colleagues followed 89,414 patients admitted for acute ischemic stroke in South Korea and sorted them by whether they hit an absolute cholesterol goal, a relative one, both, or neither.
The risk of the primary outcome was significantly higher in groups failing to achieve a 50% reduction, whether or not they had reached the absolute target.
Two goals that are usually collapsed into one
Cardiovascular guidelines actually ask for two things and most people only hear about one.
Current secondary prevention guidelines recommend both a 50% or greater reduction in LDL cholesterol from baseline and an absolute goal of under 70 or under 55 milligrams per deciliter. LDL is the form of cholesterol that builds up in arteries; a high LDL level leads to a buildup of cholesterol in your arteries.
Stroke care has quietly dropped half of that. Stroke-specific guidelines primarily emphasize only an absolute LDL-C goal, and the independent clinical impact of achieving a 50% reduction remains unclear in patients with ischemic stroke.
This study is an attempt to find out whether the dropped half was doing any work.
What the four groups showed
Patients were categorized into 4 groups according to attainment of absolute and relative goals, and compared against the group that met both.
Failing the relative goal cost something regardless of attainment of the absolute LDL level: risk was 12% higher for those who reached the target anyway, and 28% higher for those who reached neither.
The outcome was not a laboratory measure. It was a composite of recurrent stroke, myocardial infarction, and all-cause death, over a mean follow-up of 5.72 years, with 136,427 cholesterol measurements feeding a model that let each person’s risk change as their readings changed.
Results were consistent across subgroups stratified by sex, age, baseline LDL-C level, and the presence of presumed cardioembolic source, which is a reasonable check: a finding that appeared in one age band and not another would be more likely to be noise.
The 30% that is the real story
Throughout the follow-up period, the proportion of patients achieving a 50% reduction from baseline remained at approximately 30%.
Seven in ten stroke survivors in a well-resourced national health system never halved their cholesterol at any point in five years. That is a treatment gap, not a subtlety of guideline wording.
Statins are the most common medicines used to treat high cholesterol, and they lower LDL cholesterol by slowing down how much cholesterol the liver makes. Studies have shown that statins lower the risk of heart attack and stroke in people with high LDL cholesterol. Achieving a halving usually means a high-intensity statin, taken consistently, sometimes with a second drug added. Every step of that has a drop-off rate.
What could produce this without the cholesterol mattering
A person who halves their cholesterol is a person who took the tablets.
Adherence is the obvious confounder and it is a powerful one, because people who take prescribed medication reliably also attend follow-up, control their blood pressure and stop smoking more often than people who do not. That cluster of behaviors improves stroke outcomes on its own, and no administrative database records it directly.
The study cannot separate the drug effect from the patient effect. What it can say is that the relative goal carried information the absolute goal did not, and that the two groups being compared had both been prescribed something.
What a stroke survivor should ask
A stroke happens when there is a loss of blood flow to part of the brain, and after one, the entire clinical effort turns to preventing the next.
The useful question this study suggests is small and specific. If a cholesterol result comes back at target, the follow-up question is what it was before treatment started. A result of 68 that began at 74 is a different clinical situation from a result of 68 that began at 160, and only one of those has had a serious intervention behind it.
That is a conversation for the clinic rather than a reason to change anything unilaterally. The dose, the drug and whether a second agent is needed are decisions that depend on liver tests, muscle symptoms and everything else in the notes.
Underneath the target argument sits a simpler problem. Statin nonadherence is what stops most people reaching either goal, and health systems have only just begun testing the reminders they send about it.
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What did the study find?
Using the group achieving both goals as the reference, the risk of the primary outcome was significantly higher in groups failing to achieve a 50% reduction, regardless of attainment of the absolute LDL-C level: adjusted hazard ratio 1.12 (95% CI 1.06-1.18) for the under-70 mg/dL and under-50% reduction group and 1.28 (1.23-1.34) for the 70-or-above and under-50% reduction group.
What were the two goals?
An absolute one, getting LDL cholesterol below 70 mg/dL, and a relative one, cutting it by at least half from where it started. Cardiovascular prevention guidelines ask for both. Stroke-specific guidelines primarily emphasize only the absolute goal.
Why would the relative goal add anything?
Because two people can arrive at the same number from very different places. Someone starting at 75 barely needs treatment to reach 70. Someone starting at 160 needs a large intervention. The second person's arteries have been exposed to far more cholesterol, and the size of the fall records that history.
What was the outcome measured?
A composite of recurrent stroke, myocardial infarction, and all-cause death, analyzed with time-varying methods so that changing cholesterol readings over years were used as they changed, rather than fixed at one visit.
How many people met both goals?
Few. The proportion achieving a 50% or greater reduction from baseline remained at approximately 30% throughout follow-up, which is the practical finding buried in the statistics.
Is this a randomized trial?
No. It is a retrospective analysis of national insurance records. People who achieve a large cholesterol reduction are also people who take their tablets, attend appointments and are treated more intensively, and those things independently improve stroke outcomes.
What should a stroke survivor take from it?
That a cholesterol result at target is worth a second question: how far did it come down? That is a conversation with the doctor managing secondary prevention, not a reason to change a dose. This is general information rather than medical advice.