Overview of #407 – Preventing cardiovascular and Alzheimer’s disease: lowering LDL early, APOE4, and promising new therapies
Peter Attia interviews cardiologist and lipidologist Michael Davidson, M.D. about the case for earlier LDL lowering, the history and evolution of CETP inhibition, and why obicetrapib may be a major next-generation therapy for both cardiovascular disease and possibly Alzheimer’s prevention, especially in APOE4 carriers. The discussion also covers HDL biology, Lp(a), diabetes risk, omega-3s, biomarkers like p-tau 217, and the role of AI in accelerating clinical trials.
Key Takeaways
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LDL is treated as a causal driver of ASCVD, not just a risk marker.
- Davidson argues LDL should be managed more like blood pressure or smoking: the earlier the better.
- He emphasizes primordial prevention—prevent plaque from forming in the first place.
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Earlier intervention matters more than short-term risk estimates.
- The conversation pushes back on relying too heavily on 10-year risk in younger adults.
- Family history, genetics, coronary calcium, polygenic risk, Lp(a), CRP, and plaque imaging can help identify higher-risk people earlier.
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CETP inhibition has a long, messy history.
- Early CETP inhibitors were developed mainly to raise HDL, but outcomes disappointed or failed due to safety/PK issues.
- The field eventually shifted toward understanding CETP as an LDL-lowering strategy with HDL effects as secondary.
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Obicetrapib is different from the first-generation drugs.
- It is a potent, low-dose CETP inhibitor with favorable tolerability and no major fat-deposition problem.
- It lowers LDL-C, LDL-P, Lp(a), and small LDL particles, while raising HDL substantially.
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The Alzheimer’s hypothesis is biologically plausible, but still unproven clinically.
- Davidson and Attia discuss APOE4, HDL, brain cholesterol metabolism, and p-tau biomarkers.
- The hope is that raising HDL and improving lipid transport could help delay or prevent Alzheimer’s, especially in APOE4 carriers.
LDL, Prevention, and Why Timing Matters
The “causal factor” framework
Davidson repeatedly returns to the idea that LDL is not merely associated with disease; it helps cause it. That means:
- Lowering LDL before plaque exists is ideal.
- Lowering LDL after a heart attack still helps.
- Lowering LDL after heart failure appears to offer little benefit.
Lifetime exposure matters
He uses a memorable rule of thumb:
- Roughly 8 grams of lifetime cholesterol exposure is a conceptual threshold tied to heart disease risk.
- That helps explain why keeping LDL below ~80 mg/dL over a lifetime is so powerful.
Why LDL treatment is still contentious
He thinks the resistance comes from:
- Overconfidence in lifestyle-only solutions
- Discomfort with long-term drug therapy in asymptomatic people
- Guidelines that still emphasize late intervention
- A general tendency to under-recognize LDL as a causal driver
CETP Inhibitors: From HDL Hype to LDL Reality
What CETP does
CETP (cholesteryl ester transfer protein):
- Moves cholesterol from HDL to LDL
- Inhibition tends to:
- Raise HDL
- Lower LDL
- Increase cholesterol loss through bile/intestine
Why the early trials failed
The first CETP inhibitors were built during the era when HDL raising was thought to be the holy grail. But:
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Torcetrapib:
- Raised HDL dramatically
- Also raised blood pressure and aldosterone via off-target effects
- Failed with increased mortality
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Dalcetrapib:
- Safe, but too weak
- Raised HDL modestly
- No MACE benefit
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Evacetrapib:
- Potent HDL raising
- Trial stopped early for futility
- Likely didn’t run long enough to capture benefit
The turning point: LDL lowering, not HDL raising
The key Merck CETP trial showed that CETP inhibition can lower LDL enough to reduce events, validating the pathway. Davidson stresses that the real therapeutic signal is LDL lowering, not simply HDL raising.
Obicetrapib: What’s New and Why It Matters
Trial results discussed
Davidson reviews multiple studies showing:
- ~45–50% LDL-C reduction as monotherapy
- ~55% or more when combined with ezetimibe
- ~150% HDL-C increase
- ~50% Lp(a) reduction
- ~90% reduction in small LDL particles
- A signal for lower diabetes risk
Clinical trials mentioned
- ROSE / ROSE2: phase 2 biomarker studies
- BROADWAY: ASCVD patients; showed strong LDL lowering and a 21% MACE reduction signal over 1 year
- BROOKLYN: familial hypercholesterolemia patients
- TANDEM: obicetrapib + ezetimibe combination study
- PREVAIL: large outcomes trial in ASCVD, event-driven, global, and intended to support regulatory approval
Why Davidson thinks it could fit well in practice
He sees obicetrapib as a strong companion to statins because it may:
- Lower LDL further
- Reduce Lp(a)
- Reduce diabetes risk rather than increase it
- Improve the small-particle profile more than statins
That makes it appealing for patients who:
- Need more LDL lowering
- Are statin-intolerant or statin-limited
- Have high Lp(a)
- Have metabolic risk
- Need combination therapy rather than higher-dose statins
LDL-P, ApoB, Non-HDL: How to Think About Discordance
A substantial portion of the discussion focuses on lipid measurements:
- ApoB, LDL particle number (LDL-P), and non-HDL-C often track similarly, but can diverge.
- Davidson prefers LDL-P in some contexts because discordance can be easier to interpret.
- He notes that with CETP inhibition, LDL-P falls substantially, but ApoB may fall less than expected.
The takeaway:
- These are all useful markers.
- They’re not identical.
- For most patients, they point in the same direction, but discordance is clinically meaningful.
HDL: Important, But Not a Simple “Good Cholesterol”
Davidson and Attia revisit one of the biggest conceptual corrections in lipidology:
- High HDL-C is not automatically protective
- HDL can be influenced by genetics, alcohol, and dysfunctional HDL states
- HDL-raising therapies failed when tested directly
The old idea of “good cholesterol” is too simplistic. HDL still matters biologically, but raising HDL-C alone is not enough to prove benefit.
Diabetes Risk, Statins, and Why Obicetrapib Stands Out
They discuss the well-known fact that:
- Statins slightly increase diabetes risk
- The effect seems dose-related and more common in older, heavier patients
Davidson notes:
- Most LDL-lowering drugs appear to have some diabetes signal
- Obicetrapib appears to go the other way in trial data, which makes it especially interesting
He also pushes back against very high-dose statins:
- He is skeptical of routinely using maximal doses when combination therapy can often achieve similar LDL lowering with less side-effect burden.
Alzheimer’s Disease, APOE4, and Brain Lipid Biology
Why APOE4 matters
The podcast spends significant time on the idea that APOE4 is a lipid-related Alzheimer’s risk gene.
Key points:
- APOE4 impairs lipid handling in the brain
- The brain has its own cholesterol economy
- The blood-brain barrier isolates brain lipid metabolism from plasma LDL
- HDL-like particles and ApoE are central in the brain
Why CETP inhibition might help
Davidson’s rationale:
- HDL is the main lipoprotein that interfaces with the brain
- Raising HDL may help with:
- cholesterol clearance
- antioxidant delivery
- amyloid handling
- inflammatory moderation
Biomarkers and early signal
The team’s pilot and follow-up work showed:
- Decreases in 24- and 27-hydroxycholesterol
- Improvements in CSF antioxidant measures
- Better biomarker profiles in APOE4 carriers, especially E4/E4 homozygotes
- Improvement in p-tau 217, p-tau 181, GFAP, Aβ42/40, and neurofilament light in the broader biomarker analyses
The core argument
They believe Alzheimer’s is often a middle-age disease that presents in old age:
- By the time MCI appears, the disease may already be too advanced
- Prevention likely needs to begin well before symptoms
Omega-3s: EPA, DHA, and Brain Delivery
Davidson gives a nuanced view of omega-3s:
EPA
- He believes EPA has evidence for cardiovascular benefit
- Benefit likely comes from:
- anti-thrombotic effects
- anti-inflammatory effects
- perhaps triglyceride lowering, though that may not be the main driver
DHA
- DHA is a major structural fat in the brain
- But ordinary DHA supplementation may not deliver enough to the brain
- A key new insight is that brain uptake depends on the MFSD2A transporter
- The preferred form is lysophosphatidylcholine-DHA (LPC-DHA)
His expectation:
- Better brain-targeted DHA formulations may become available
- This could be relevant for brain health, especially in APOE4 carriers
AI and the Future of Clinical Trials
Davidson is optimistic about AI’s role in drug development, especially in:
- Trial design
- Patient selection
- Compliance analysis
- Reducing wasted data from non-adherent participants
- Speeding up evidence generation
He argues that AI could help move trials from:
- 10,000 patients to 2,000
- 10 years to 1 year
- $3–4 billion development costs to something far more tractable
His bigger point:
Clinical trial regulation still needs reform for AI to have its full impact.
Practical Clinical Implications
For cardiovascular prevention
- Treat LDL early, not just after disease appears
- Use genetics and imaging to refine risk
- Prefer combination therapy when possible rather than escalating statin dose alone
- Be aware that LDL lowering benefit is largely independent of the specific drug used
For patients with APOE4
- Knowing genotype may be motivating and actionable
- Focus on:
- exercise
- weight management
- blood pressure
- glucose control
- lipid control
- smoking avoidance
- possibly DHA optimization
For clinicians
- Don’t assume:
- high HDL means low risk
- lifestyle alone will fix inherited LDL elevation
- late-stage Alzheimer’s trials tell the whole story
- Think in terms of causal biology and earlier intervention
Bottom Line
This episode argues that the future of prevention may come from treating causal biology earlier and more precisely. On the cardiovascular side, obicetrapib may become a powerful addition to the lipid-lowering toolkit if PREVAIL is positive. On the neurodegenerative side, Davidson makes a compelling case that HDL biology, APOE4, and lipid transport in the brain could open a new prevention pathway for Alzheimer’s disease—especially if intervention happens before MCI.