Cardiovascular

Hyperlipidemia: secondary prevention and non-statin add-ons

Clinical Overview and When to Suspect Residual ASCVD Risk on Statin Therapy

— LDL-C remains ≥70 mg/dL (or ≥55 in very-high-risk) despite maximally tolerated statin (atorvastatin 40–80 or rosuvastatin 20–40).

— Statin intolerance (true myopathy, rhabdo history, rising CK with rechallenge).

— Recurrent ASCVD event while on therapy ("breakthrough" event = automatically very high risk).

— Familial hypercholesterolemia phenotype (LDL ≥190 untreated, tendon xanthomas, premature CAD family hx).

Board pearl: On Step 3, the trigger to add ezetimibe or a PCSK9 inhibitor is not a calculated risk score — it is a persistent LDL above the threshold (70 or 55) on maximally tolerated statin in a patient with established ASCVD. Always document the statin dose and adherence before escalating; "patient stopped atorvastatin due to vague aches" is a re-challenge scenario, not an add-on scenario.

Secondary prevention = patient already has clinical atherosclerotic cardiovascular disease (ASCVD): prior MI, ACS, stable angina with documented coronary disease, coronary/peripheral revascularization, ischemic stroke/TIA of atherosclerotic origin, or symptomatic PAD (claudication with ABI ≤0.90, prior limb revascularization, aortic aneurysm of atherosclerotic origin).

These patients are already past the primary-prevention risk-calculator stage — no pooled cohort equation needed. The 2018 AHA/ACC/Multisociety cholesterol guideline and 2022 ACC ECDP put them on high-intensity statin by default, with LDL-C goal <70 mg/dL (and many experts/2022 ECDP favor <55 mg/dL in very high-risk ASCVD).

When to suspect a patient needs non-statin add-on therapy:

Very high-risk ASCVD (drives the <55 target and lowers threshold to add non-statin): multiple major events OR one major event plus multiple high-risk conditions (DM, HTN, CKD, smoking, HFrEF, age ≥65, persistent LDL ≥100 on max statin, prior CABG/PCI outside the index event, FH).

Presentation Patterns and Key History

— Index ASCVD event(s): type (ACS vs stable CAD vs stroke vs PAD), date, revascularization performed, residual disease burden.

— Current lipid-lowering regimen: drug, dose, duration, adherence (ask explicitly — "how many days a week do you miss?"), prior intolerances.

— Symptoms of statin-associated muscle symptoms (SAMS): bilateral proximal myalgia, onset within weeks of starting/up-titration, resolution with washout, recurrence on rechallenge. Distinguish from nocebo (very common).

— Comorbidities affecting choice: CKD (avoid high-dose simvastatin/lovastatin; rosuvastatin dose-cap), liver disease, hypothyroidism (must replace before declaring statin failure — TSH can drive LDL up 30+ points), diabetes, alcohol use.

— Family history: premature CAD (<55 men, <65 women) and LDL ≥190 → screen for FH; cascade screen first-degree relatives.

— Diet/lifestyle: saturated fat, sedentary behavior, smoking, weight trajectory — must be addressed in parallel, not instead of pharmacotherapy.

Step 3 management: Always recheck a lipid panel 4–12 weeks after initiation or dose change, then every 3–12 months thereafter. The vignette's repeat LDL is the action trigger.

The "presentation" in secondary-prevention lipid management is almost always a follow-up visit or post-discharge transition, not an acute symptom. Step 3 vignettes typically read: "6 weeks after NSTEMI, patient returns; LDL is 92 on atorvastatin 80…" Recognize the scaffolding cues: time since event, current statin dose, adherence, side effects, repeat lipid panel.

High-yield history to extract:

Key distinction: A patient whose LDL dropped appropriately (e.g., from 160 → 75 on atorvastatin 80) but remains just above goal is a candidate for add-on ezetimibe — not a statin switch. A patient who reports muscle aches but has normal CK and the aches preceded the statin is a nocebo/rechallenge scenario — re-trial, do not jump to PCSK9i.

Physical Exam Findings (and Vascular Assessment)

— Tendon xanthomas — firm, painless nodules on Achilles tendon or extensor tendons of the hands (MCP joints). Pathognomonic for heterozygous FH when present; mandate genetic/cascade screening.

— Xanthelasma — yellowish periorbital plaques; less specific (can occur with normal lipids) but should prompt a lipid panel.

— Corneal arcus before age 45 — suggestive of FH; in older patients it is age-related and nonspecific.

— Eruptive xanthomas — yellow papules on buttocks/extensor surfaces — indicate severe hypertriglyceridemia (TG often >1000) and pancreatitis risk, not LDL-driven.

— Palmar xanthomas (xanthoma striata palmaris) — orange-yellow streaks in palmar creases — classic for dysbetalipoproteinemia (type III, ApoE2/E2).

— Carotid bruits, diminished pedal pulses, femoral bruits, AAA palpation in older men.

— Ankle-brachial index (ABI) in any patient with claudication or non-healing wound — ABI ≤0.90 confirms PAD and qualifies as secondary-prevention indication.

— Skin changes of chronic PAD: hair loss, shiny atrophic skin, dependent rubor, ulcers at pressure points.

— Document BP at every visit (target <130/80 in ASCVD).

— BMI/waist circumference for metabolic syndrome co-management.

— Thyroid exam (occult hypothyroidism elevates LDL).

Board pearl: Tendon xanthomas + LDL ≥190 + premature family CAD = heterozygous FH until proven otherwise. These patients need high-intensity statin plus ezetimibe up front, with low threshold to add a PCSK9 inhibitor — even at the first visit. Screen first-degree relatives (cascade testing).

Hyperlipidemia is largely a lab diagnosis, but exam findings carry diagnostic weight, especially for familial hypercholesterolemia (FH) and for tracking vascular disease progression in secondary prevention.

Cutaneous and ocular findings (high-yield for FH and severe dyslipidemia):

Vascular exam in established ASCVD:

Cardiovascular and systemic:

Diagnostic Workup — Initial Labs and Baseline Studies

— Total cholesterol, LDL-C (calculated or measured), HDL-C, triglycerides.

— Non-HDL cholesterol = TC − HDL; useful when TG >200 (LDL calculation unreliable). Target = LDL goal + 30 (so <100 if LDL goal <70).

— ApoB — increasingly used as the most accurate atherogenic-particle measure; reasonable in patients with elevated TG, metabolic syndrome, or discordant LDL. Target <65 mg/dL in very-high-risk ASCVD.

— Lp(a) — measure once in a lifetime in any patient with ASCVD, FH, or strong family history; ≥50 mg/dL (or ≥125 nmol/L) confers residual risk and supports aggressive LDL lowering.

— ALT/AST baseline (routine LFT monitoring is no longer required unless symptoms).

— Creatine kinase (CK) only if patient has muscle symptoms or high myopathy risk (elderly, small body habitus, hypothyroidism, interacting drugs, Asian ancestry on rosuvastatin).

— TSH — must rule out hypothyroidism before labeling LDL as refractory.

— HbA1c / fasting glucose — statins slightly increase incident diabetes; benefit outweighs risk in secondary prevention.

— Creatinine/eGFR — dose-adjust rosuvastatin if eGFR <30.

— Pregnancy test in reproductive-age women before statin initiation.

Step 3 management: When the vignette shows TG 320 and LDL 95, switch your target to non-HDL <100 (or ApoB <80) — calculated LDL is unreliable. Don't be tricked into declaring the LDL "at goal."

Fasting vs non-fasting lipid panel: current guidance accepts non-fasting for routine screening and follow-up. Fasting is preferred when TG >400 on non-fasting, in suspected familial dyslipidemia, or before initiating high-risk therapy.

Baseline panel components:

Pre-treatment safety labs:

Follow-up labs after starting/changing therapy: lipid panel 4–12 weeks post-initiation, then every 3–12 months.

Diagnostic Workup — Advanced and Confirmatory Studies

— Consider in untreated LDL ≥190, tendon xanthomas, or premature ASCVD with strong family history.

— Confirmation enables cascade screening of first-degree relatives (children screened by age 9–11, earlier if FH parent).

— Pathogenic variants in LDLR, APOB, PCSK9 confirm heterozygous FH; homozygous FH (LDL often >400) is rare and needs LDL apheresis, evinacumab (ANGPTL3 inhibitor), or lomitapide.

— Stress testing / coronary CTA — for new or worsening symptoms, not for routine lipid follow-up.

— Carotid duplex in patients with stroke/TIA or carotid bruit.

— ABI ± lower-extremity duplex for suspected PAD.

— Hypothyroidism (TSH).

— Nephrotic syndrome (urinalysis, urine protein/Cr).

— Cholestatic liver disease (alkaline phosphatase, bilirubin).

— Uncontrolled diabetes (HbA1c).

— Medications: thiazides, beta-blockers, atypical antipsychotics, corticosteroids, cyclosporine, protease inhibitors, oral estrogens (raise TG).

Key distinction: In a patient with LDL "not responding" to a statin, rule out secondary causes (TSH, urine protein, A1c, medication review) before adding ezetimibe or a PCSK9i. A missed diagnosis of hypothyroidism is a classic Step 3 trap that obviates the need for any add-on therapy.

Coronary artery calcium (CAC) scoring — primarily a primary-prevention decision aid for borderline/intermediate-risk adults aged 40–75. In secondary prevention, CAC is not indicated — disease is already established.

Genetic testing for familial hypercholesterolemia:

Lp(a) — one-time measurement in ASCVD patients; elevated values (≥50 mg/dL) are independent risk amplifiers. No FDA-approved Lp(a)-specific drug yet (pelacarsen in trials), so the management response is lower LDL more aggressively.

Imaging to characterize ASCVD burden when it changes management:

Workup for secondary hyperlipidemia before declaring resistance:

Risk Stratification and Management Logic in Secondary Prevention

— Stable ASCVD (not very high-risk) → LDL goal <70 mg/dL; add ezetimibe if not achieved on max statin.

— Very high-risk ASCVD → LDL goal <55 mg/dL (per 2022 ACC ECDP and ESC); lower threshold to escalate to PCSK9i or other add-ons.

— Major events: recent ACS (<12 mo), MI history, ischemic stroke, symptomatic PAD.

— High-risk conditions: age ≥65, heterozygous FH, prior CABG/PCI outside the index event, DM, HTN, CKD (eGFR 15–59), current smoking, persistent LDL ≥100 despite max therapy, HF history.

1. Maximally tolerated high-intensity statin (atorvastatin 40–80 or rosuvastatin 20–40) — expect ≥50% LDL reduction.

2. Add ezetimibe 10 mg if LDL above threshold → additional ~18–25% reduction (IMPROVE-IT trial: incremental ASCVD benefit post-ACS).

3. Add PCSK9 monoclonal (alirocumab or evolocumab) if still above threshold, especially in very-high-risk patients (FOURIER, ODYSSEY OUTCOMES).

4. Bempedoic acid if statin-intolerant or for additional lowering (CLEAR Outcomes: 13% MACE reduction).

5. Inclisiran (siRNA, q6mo SC) as alternative to PCSK9 mAb.

6. Icosapent ethyl if TG 150–499 on statin in established ASCVD (REDUCE-IT: 25% MACE reduction).

Board pearl: The order matters on the exam — statin → ezetimibe → PCSK9i. Skipping ezetimibe straight to a PCSK9i is wrong unless the patient is statin-intolerant or has homozygous FH / very-high-risk with LDL far above goal. PCSK9i pre-authorization usually requires documented failure of statin + ezetimibe.

Every ASCVD patient stratifies into one of two buckets that drive add-on decisions:

Very high-risk = ≥2 major ASCVD events OR 1 major event + ≥2 high-risk conditions:

Sequential escalation algorithm (Step 3 favorite):

Lifestyle anchors every step: Mediterranean/DASH diet, ≥150 min/wk moderate exercise, smoking cessation, weight management, alcohol moderation.

Pharmacotherapy — Statins and Core Add-On Agents

— High-intensity (≥50% LDL ↓): atorvastatin 40–80, rosuvastatin 20–40.

— Moderate-intensity (30–49% ↓): atorvastatin 10–20, rosuvastatin 5–10, simvastatin 20–40, pravastatin 40–80.

— Pleiotropic effects: plaque stabilization, endothelial function, anti-inflammatory (lowers hsCRP).

— AEs: myalgia (5–10%, mostly nocebo), rhabdomyolysis (rare, <0.1%), transaminitis (usually mild), new-onset diabetes (~1 per 1000 pt-yrs — benefit outweighs in 2° prevention), cognitive complaints (no causal link in RCTs).

— Interactions: CYP3A4 (simva, atorva, lova) with macrolides, azoles, protease inhibitors, amiodarone, diltiazem — rosuvastatin and pravastatin safer in polypharmacy.

— ~18–25% additional LDL reduction; minimal AEs; first add-on after max statin.

— IMPROVE-IT: post-ACS ezetimibe + simva reduced MACE.

— SC q2 weeks (or monthly evolocumab); 50–60% additional LDL reduction.

— Indications: very-high-risk ASCVD with LDL ≥70 (or non-HDL ≥100) on max statin + ezetimibe; HeFH; HoFH (evolocumab); statin intolerance.

— AEs: injection-site reactions, rare nasopharyngitis. Safe in pregnancy data limited — avoid.

Step 3 management: Do not stop a statin for an asymptomatic ALT rise <3× ULN. Stop for ALT/AST >3× ULN with symptoms or CK >10× ULN / rhabdomyolysis. After resolution, rechallenge with a different statin at low dose.

Statins (HMG-CoA reductase inhibitors) — cornerstone:

Ezetimibe 10 mg daily — inhibits NPC1L1 cholesterol absorption.

PCSK9 monoclonal antibodies — alirocumab (Praluent), evolocumab (Repatha):

Inclisiran — siRNA targeting hepatic PCSK9 mRNA; SC at 0, 3 mo, then q6 months. ~50% LDL ↓; adherence advantage.

Bempedoic acid — ATP-citrate lyase inhibitor, oral. ~17–20% LDL ↓ as monotherapy; does not enter muscle → ideal for statin-intolerant. CLEAR Outcomes: cardiovascular benefit. AEs: hyperuricemia/gout, tendon rupture (rare).

Expanded Pharmacology — Triglyceride-Lowering and Specialty Agents

— Indicated in established ASCVD or DM + ≥2 risk factors, with TG 150–499 on statin.

— REDUCE-IT: 25% MACE reduction, 20% CV death reduction.

— AEs: atrial fibrillation (modest ↑), bleeding risk (esp. with antiplatelets/anticoagulants), peripheral edema.

— Key distinction: Mixed omega-3 preparations (EPA + DHA) failed to show CV benefit (STRENGTH trial) and may slightly raise LDL. Only pure EPA (icosapent ethyl) has guideline support.

— Primarily for TG >500 to prevent pancreatitis (severe hypertriglyceridemia).

— No proven ASCVD reduction when added to statin in well-controlled LDL.

— Gemfibrozil + statin → high myopathy risk (avoid combo). Fenofibrate preferred if combination needed.

— Renal dose adjust; can raise creatinine modestly (not true nephrotoxicity).

— Niche use: pregnancy (not systemically absorbed), pruritus of cholestasis, mild LDL lowering, type 2 DM adjunct (colesevelam).

— AEs: GI bloating, ↑TG; interfere with drug absorption (separate dosing).

— Evinacumab (ANGPTL3 mAb) — IV monthly; for HoFH; ~50% LDL ↓ independent of LDLR.

— Lomitapide (MTP inhibitor) — oral; HoFH only; hepatic steatosis risk; REMS program.

— LDL apheresis — biweekly; HoFH and refractory HeFH.

Board pearl: When TG >500, the priority is pancreatitis prevention, not ASCVD reduction — start fibrate ± omega-3 ± dietary fat restriction first; statin is added later for LDL/ASCVD risk once TG drops below 500.

Icosapent ethyl (Vascepa) 2 g BID — purified EPA:

Fibrates (fenofibrate, gemfibrozil) — PPAR-α agonists:

Niacin — largely abandoned for ASCVD prevention (AIM-HIGH, HPS2-THRIVE: no benefit, ↑ AEs: flushing, hyperglycemia, hepatotoxicity, gout).

Bile acid sequestrants (cholestyramine, colesevelam):

Specialty agents for FH:

Special Populations — Elderly and Renal/Hepatic Impairment

— Continue statin therapy for secondary prevention regardless of age — benefit persists (PROSPER, meta-analyses).

— Consider moderate-intensity if high-intensity not tolerated; frailty, life expectancy <5 yr, and polypharmacy may justify de-escalation discussions.

— Drug interactions matter more: rosuvastatin or pravastatin preferred (non-CYP3A4).

— Falls risk does not contraindicate statins.

— Ezetimibe is well tolerated in elderly; PCSK9i safe; bempedoic acid safe but watch gout.

— eGFR ≥30: full-dose statins generally fine; cap rosuvastatin at 10 mg if eGFR <30.

— Dialysis patients: do not initiate a statin solely for primary prevention (4D, AURORA: no benefit); continue if already on one for established ASCVD.

— Ezetimibe + simvastatin (SHARP) reduced MACE in CKD — useful combo.

— Fenofibrate: avoid if eGFR <30; can falsely raise creatinine.

— PCSK9 inhibitors: no renal dose adjustment.

— Lp(a) is elevated in CKD/nephrotic syndrome — contributes to residual risk.

— Active liver disease or unexplained persistent ALT/AST >3× ULN: contraindication to statin initiation.

— Compensated cirrhosis (Child-Pugh A) and NAFLD: statins safe and beneficial; NAFLD is not a reason to withhold.

— Decompensated cirrhosis (Child-Pugh B/C): use cautiously or avoid.

— Ezetimibe: avoid in moderate-severe hepatic impairment.

— Bempedoic acid: caution; monitor LFTs.

Step 3 management: A patient on dialysis with prior MI on atorvastatin 40 mg should continue the statin. Do not stop it because they "started dialysis" — the question is testing whether you know secondary-prevention statin benefit persists despite the lack of primary-prevention benefit.

Elderly (≥75 years) with established ASCVD:

Chronic kidney disease:

Hepatic impairment:

Special Populations — Pregnancy, Pediatrics, and Women's Health

— Statins: historically Category X, but 2021 FDA removed the broadest contraindication. Still, stop statins before conception or when pregnancy confirmed in most patients with stable ASCVD; may continue in HoFH or very-high-risk patients after shared decision-making.

— Ezetimibe, PCSK9 inhibitors, fibrates, niacin, bempedoic acid, inclisiran: avoid in pregnancy (insufficient safety data).

— Safe options: bile acid sequestrants (cholestyramine, colesevelam) — not systemically absorbed; useful for severe hypercholesterolemia in pregnancy.

— LDL apheresis for HoFH during pregnancy.

— Resume statin after delivery; if breastfeeding, avoid statins (preferentially defer until weaned) — pravastatin sometimes used if necessary.

— Pregnancy test before initiating in reproductive-age women; counsel on contraception.

— Universal lipid screening once between ages 9–11 and again at 17–21 (AAP/NHLBI).

— Selective earlier screening if family history of FH or premature CAD.

— Heterozygous FH: start statin at age 8–10 if LDL ≥190 (or ≥160 with family history); ezetimibe and PCSK9i (evolocumab approved ≥10 yr) available.

— Homozygous FH: aggressive multi-drug therapy plus apheresis.

— Postmenopausal estrogen therapy: not indicated for ASCVD prevention.

— Oral contraceptives can raise TG; switch to non-oral or non-estrogen forms if severe hypertriglyceridemia.

— Pregnancy complications (preeclampsia, gestational DM, preterm birth) are now recognized as female-specific ASCVD risk enhancers.

Board pearl: The reproductive-age woman with HeFH on atorvastatin who is planning pregnancy → discontinue statin 1–3 months pre-conception, transition to bile acid sequestrant if LDL very high, resume statin after delivery (and after breastfeeding completion).

Pregnancy and lactation:

Pediatrics:

Women, hormonal considerations:

Complications and Adverse Outcomes

— Spectrum: myalgia (pain without CK ↑), myositis (CK ↑), rhabdomyolysis (CK >10× ULN, myoglobinuria, AKI — rare).

— Most muscle complaints are nocebo: SAMSON trial showed identical symptom scores on statin vs placebo.

— Management: hold statin until symptoms resolve, check CK and TSH, rule out interacting drugs, rechallenge with same or different statin at lower dose, then up-titrate. Try alternate-day rosuvastatin if persistent.

— Mild transaminitis common, usually self-resolving.

— Discontinue only if ALT/AST >3× ULN with symptoms or bilirubin rise (Hy's law concern). Routine LFT monitoring no longer mandated.

Key distinction: Asymptomatic CK elevation <5× ULN does not require statin discontinuation. Stop only for CK >10× ULN, symptomatic CK >5× ULN, or any rhabdomyolysis features.

Statin-associated muscle symptoms (SAMS) — the most common reason for non-adherence:

Hepatotoxicity:

New-onset diabetes mellitus — ~9% relative risk increase; absolute risk small; cardiovascular benefit clearly outweighs in secondary prevention.

Hemorrhagic stroke — small absolute increase in patients with prior hemorrhagic stroke; weigh risk-benefit.

Drug interactions causing myopathy — macrolides, azole antifungals, protease inhibitors, cyclosporine, gemfibrozil, amiodarone, diltiazem, verapamil, grapefruit juice (CYP3A4). Pause simvastatin/atorvastatin during short courses of clarithromycin/itraconazole.

Ezetimibe: very well tolerated; rare diarrhea, myalgia.

PCSK9 inhibitors: injection-site reactions, rare hypersensitivity; no neurocognitive signal in long-term trials.

Bempedoic acid: hyperuricemia and gout, tendon rupture (rare), modest LDL ↑ in muscle but no muscle toxicity — major selling point.

Icosapent ethyl: atrial fibrillation/flutter (~3% absolute increase), bleeding.

Fibrates: myopathy (especially with statin), gallstones, transaminitis, creatinine ↑.

When to Escalate Care — Specialist Referral and Inpatient Considerations

— Suspected or confirmed familial hypercholesterolemia (LDL ≥190 untreated, tendon xanthomas, premature family CAD).

— Statin intolerance with multiple statin trials failed and LDL still elevated.

— Need for PCSK9 inhibitor, inclisiran, bempedoic acid, evinacumab, or lomitapide — prior authorization complexity often easier via lipid specialist.

— Recurrent ASCVD event on optimized therapy ("breakthrough event").

— Severe hypertriglyceridemia (TG >1000) — pancreatitis risk; may need apheresis or specialty management.

— Homozygous FH — refer for LDL apheresis program access.

— Acute coronary syndrome — initiate or continue high-intensity statin immediately during admission (do not wait for outpatient). Pre-discharge lipid panel for baseline reference.

— Acute pancreatitis from severe hypertriglyceridemia (TG >1000) — admit; supportive care, NPO, IV fluids; insulin infusion (with dextrose if normoglycemic) lowers TG; consider plasmapheresis if TG >2000 with organ dysfunction. Start fibrate once tolerating PO.

— Rhabdomyolysis from statin — admit if CK markedly elevated with AKI; IV fluids, electrolyte correction, hold statin permanently or rechallenge later with caution.

CCS pearl: On a CCS case of NSTEMI, in the first 24 hours, order atorvastatin 80 mg PO daily, aspirin, P2Y12 inhibitor, beta-blocker, ACEi/ARB, anticoagulation, troponin trend, ECG, echo. Move clock forward; schedule lipid panel at 4–6 weeks in the office. If LDL ≥70, add ezetimibe; reassess at 4–12 weeks; if still ≥70 and very-high-risk, add PCSK9i.

Lipid clinic / cardiology referral indications:

Inpatient escalation:

Endocrinology referral if multiple secondary causes (uncontrolled DM, hypothyroidism) drive lipid abnormality.

Key Differentials — Other Lipid Disorders Mimicking "Refractory Hyperlipidemia"

— Autosomal dominant (LDLR, APOB, PCSK9 mutations); prevalence ~1:250.

— Untreated LDL 190–400, tendon xanthomas, premature CAD (<55 men/<65 women), strong family history.

— Requires high-intensity statin + ezetimibe ± PCSK9i from diagnosis.

— Untreated LDL often >500; childhood xanthomas, aortic stenosis, CAD by teens/20s.

— Needs multi-drug therapy + LDL apheresis + evinacumab/lomitapide.

— Mixed elevations (LDL + TG); most common genetic dyslipidemia (~1–2%); polygenic.

— Strong family history of mixed dyslipidemia and early CAD.

— Manage with statin ± fibrate or icosapent ethyl based on TG.

— Elevated TC and TG (both ~300–500); palmar xanthomas (xanthoma striata palmaris) — pathognomonic.

— Responds well to fibrate ± statin.

— LPL deficiency, ApoC-II deficiency, ApoA-V deficiency, or polygenic.

— TG often >1000; eruptive xanthomas, lipemic serum, recurrent pancreatitis.

— Management: extreme dietary fat restriction, fibrate, omega-3, volanesorsen (rare), avoid alcohol/estrogen.

Key distinction: Palmar xanthomas → dysbetalipoproteinemia. Tendon xanthomas → FH. Eruptive xanthomas → severe hypertriglyceridemia. Xanthelasma → nonspecific but check lipids. These four exam shortcuts come up repeatedly.

Heterozygous familial hypercholesterolemia (HeFH):

Homozygous FH (HoFH):

Familial combined hyperlipidemia (FCH):

Familial dysbetalipoproteinemia (Type III, ApoE2/E2):

Familial hypertriglyceridemia / chylomicronemia:

Tangier disease, abetalipoproteinemia, sitosterolemia — rare, board-tested at the buzzword level.

Key Differentials — Secondary Causes of Dyslipidemia

— Hypothyroidism — raises LDL by 30–50%; check TSH in every "refractory" case. Treating hypothyroidism may normalize LDL without further intervention.

— Uncontrolled diabetes mellitus — raises TG, lowers HDL; tighten glycemic control.

— Cushing syndrome, growth hormone excess — less common but produce mixed dyslipidemia.

— PCOS — atherogenic profile (↑TG, ↓HDL).

— Nephrotic syndrome — proteinuria drives hepatic lipoprotein overproduction; check UA/UPCR.

— CKD — multifactorial dyslipidemia; elevates Lp(a).

— Cholestatic liver disease (PBC) — markedly elevated cholesterol with xanthomas; bile acid sequestrants useful.

— NAFLD — atherogenic dyslipidemia (↑TG, ↓HDL, small dense LDL); statins safe and beneficial.

— Thiazides, beta-blockers — modest TG ↑, LDL ↑.

— Atypical antipsychotics (olanzapine, clozapine) — significant ↑TG, weight gain.

— Corticosteroids, cyclosporine, tacrolimus — atherogenic profile.

— Protease inhibitors (HIV therapy) — marked TG ↑.

— Oral estrogens, tamoxifen — TG ↑.

— Isotretinoin — TG ↑.

— Alcohol — TG ↑↑.

— High saturated fat / refined carbohydrate diet.

— Obesity and sedentary lifestyle.

Step 3 management: Workup for refractory LDL = TSH, urine protein, HbA1c, medication review, alcohol/diet history — all before adding a PCSK9 inhibitor. A normal TSH on the chart before the lipid panel was drawn doesn't count if labs are old; recheck.

Before labeling a patient as statin-resistant or escalating to expensive add-ons, rule out secondary causes — Step 3 favorite trap:

Endocrine causes:

Renal causes:

Hepatic causes:

Medication-induced:

Lifestyle/dietary:

Secondary Prevention Bundle — Discharge Medications and Long-Term Plan

— Antiplatelet: aspirin 81 mg daily indefinitely; DAPT (aspirin + P2Y12 inhibitor) for 6–12 months post-ACS/PCI, then de-escalate based on bleeding/ischemic risk.

— Blood pressure control: target <130/80; preferred agents post-MI/HF: ACEi/ARB + beta-blocker; add others as needed.

— Cholesterol: high-intensity statin + ezetimibe + PCSK9i as needed to drive LDL <70 (or <55 if very-high-risk); ApoB or non-HDL secondary targets.

— Diabetes: HbA1c <7% individualized; SGLT2 inhibitor or GLP-1 RA preferred in DM + ASCVD for proven CV benefit.

— Exercise + diet: ≥150 min/wk moderate-intensity aerobic + 2 sessions resistance training; Mediterranean or DASH diet.

— Smoking cessation: pharmacotherapy (varenicline, bupropion, NRT) + counseling at every visit.

— Weight: BMI <25; consider GLP-1 RAs in obesity + ASCVD.

— Cardiac rehabilitation referral: Class I indication post-MI, post-PCI, post-CABG, stable angina, PAD, HF.

— Influenza, COVID-19, pneumococcal, RSV vaccines per age — ASCVD is a vaccine indication.

— ACE inhibitor if EF <40%, HTN, DM, CKD.

— Beta-blocker for at least 1 year (longer if reduced EF).

— MRA (spironolactone/eplerenone) if EF <40% with HF or DM.

CCS pearl: Failing to put a post-MI patient on all five (aspirin, statin, beta-blocker, ACEi/ARB, P2Y12 inhibitor) at discharge costs points. Add cardiac rehab referral and smoking cessation counseling as separate orders — both score independently.

Every patient with established ASCVD should leave the office/hospital on a secondary-prevention quadrant (memorize the "ABCDE" or "GDMT" stack):

Post-MI specific:

Annual influenza vaccine reduces ASCVD events (Class I recommendation in AHA).

Follow-Up, Monitoring Parameters, and Cardiac Rehab

— Repeat lipid panel 4–12 weeks after starting or changing therapy.

— Once at goal: every 3–12 months.

— Annual follow-up minimum for stable patients.

— Recheck after weight changes, new diagnoses (DM, CKD, hypothyroidism), or medication interactions.

— Direct questioning ("how many doses do you miss per week?").

— Pharmacy refill records.

— Address cost barriers (generics, 90-day fills, patient assistance for PCSK9i).

— LFTs only if symptoms or other concerns — not routine.

— CK only if muscle symptoms.

— TSH if LDL rises unexpectedly.

— HbA1c annually given statin-DM signal.

— Uric acid annually if on bempedoic acid, especially with gout history.

— 36 sessions over 12 weeks typically covered by Medicare for post-MI, post-PCI, post-CABG, stable angina, valve surgery, HF (EF ≤35%), PAD.

— Reduces all-cause mortality ~20–25%, cardiac mortality ~25–30%; under-prescribed (only ~30% referred).

— Components: supervised exercise, risk-factor education, psychosocial support, dietary counseling, smoking cessation.

— Reinforce diet (Mediterranean/DASH), exercise, smoking cessation.

— Update on medication adherence and side effects.

— Depression screening (PHQ-2/9) — depression worsens ASCVD outcomes and adherence.

— Vaccinations review.

Board pearl: When a vignette describes a post-MI patient asking how to lower future risk beyond medications, the highest-yield answer is cardiac rehabilitation referral — it has independent mortality benefit and is consistently under-utilized. It will be the correct answer over "increase exercise on your own."

Lipid follow-up cadence:

Adherence assessment at every visit — most common cause of "non-response":

Safety monitoring:

Cardiac rehabilitation (Class I, evidence A):

Counseling at each visit:

Ethical, Legal, and Patient Safety Considerations

— At discharge after ACS, medication reconciliation must include high-intensity statin initiation; statin "not started in hospital" is a quality-measure failure (CMS, Joint Commission core measures).

— Communicate add-on plan to outpatient physician: scheduled 4–6 week follow-up with lipid panel, planned ezetimibe addition if needed. Use structured discharge summaries within 48 hours.

— Patient education: when to call (muscle pain, dark urine, jaundice), how to obtain medications, importance of adherence.

— Discuss cost, injection technique, expected benefit (absolute risk reduction ~1.5–2% over 2–3 years in FOURIER), uncertainty about very long-term safety.

— Document shared decision-making.

— Index patient consent required to contact relatives; encourage but do not coerce family disclosure.

— Genetic counseling for affected families; address employment and insurance discrimination concerns (GINA in the US protects against health insurance/employer discrimination but not life/disability insurance).

— Document discussion of contraception in reproductive-age women on statins.

— Plan preconception statin discontinuation in non-HoFH patients.

— In patients with life expectancy <1 year or in hospice, deprescribing statins is appropriate and ethical — improves quality of life without compromising survival (palliative care RCTs).

— Discuss with patient/family; document goals-of-care alignment.

— Women and minorities are historically under-prescribed high-intensity statins and PCSK9 inhibitors; audit your own prescribing.

Step 3 management: A 92-year-old with metastatic cancer and 6-month prognosis on atorvastatin 40 for old MI — the right answer is to discontinue the statin as part of goals-of-care/palliative deprescribing, after discussion with the patient.

Transition-of-care safety — the dominant Step 3 safety theme in lipid management:

Informed consent for PCSK9 inhibitors and other expensive therapies:

Cascade screening ethics in FH:

Pregnancy and reproductive counseling:

Statin discontinuation in advanced illness:

Avoiding under-treatment bias:

High-Yield Associations and Rapid-Fire Clinical Facts

Board pearl: Memorize "70 / 55 / 30 / IMPROVE-IT / FOURIER / REDUCE-IT" — these six anchors generate 80% of correct answers on Step 3 lipid stems.

LDL targets: <70 stable ASCVD; <55 very-high-risk ASCVD; ≥50% reduction from baseline with high-intensity statin.

Non-HDL target = LDL target + 30 (so <100 in stable ASCVD, <85 in very-high-risk).

ApoB target: <80 stable ASCVD; <65 very-high-risk.

High-intensity statins: only atorvastatin 40–80 and rosuvastatin 20–40.

IMPROVE-IT: ezetimibe + simvastatin reduced MACE post-ACS (the trial that legitimized "lower is better" beyond statins).

FOURIER (evolocumab) & ODYSSEY OUTCOMES (alirocumab): PCSK9i ↓ MACE in ASCVD.

REDUCE-IT: icosapent ethyl 2 g BID ↓ MACE 25% in statin-treated patients with TG 150–499 and ASCVD/DM+RF.

CLEAR Outcomes: bempedoic acid ↓ MACE 13% in statin-intolerant.

SHARP: simva + ezetimibe ↓ MACE in CKD.

JUPITER: rosuvastatin ↓ events in primary prevention with elevated hsCRP.

Lp(a) ≥50 mg/dL → independent risk; measure once in lifetime.

Tendon xanthomas → FH. Palmar xanthomas (striata) → dysbetalipoproteinemia (ApoE2/E2). Eruptive xanthomas → severe ↑TG. Xanthelasma → nonspecific.

TG >500 → focus on pancreatitis prevention (fibrate, omega-3, diet).

TG >1000 → admit consideration; insulin infusion lowers TG; consider apheresis.

Statin-induced rhabdo risk factors: elderly, female, small habitus, hypothyroidism, CKD, CYP3A4 interactions, Asian ancestry on rosuvastatin.

Statin in NAFLD/compensated cirrhosis → safe and beneficial.

Statin in dialysis primary prevention → no benefit; continue if already on for ASCVD.

Annual influenza vaccine = Class I in ASCVD.

Cardiac rehab ↓ mortality 20–25% post-MI.

First add-on after maxed statin = ezetimibe (cheap, oral, well-tolerated).

Order of escalation: lifestyle → high-intensity statin → ezetimibe → PCSK9i/inclisiran → bempedoic acid → icosapent ethyl (if TG residual).

Board Question Stem Patterns

"6 weeks post-NSTEMI, 62 y/o on atorvastatin 80, LDL 88, TG 140. Next step?"

→ Add ezetimibe 10 mg daily. Not a PCSK9i (ezetimibe first). Not switch statin (already maxed). Not lifestyle alone.

"Recurrent MI on atorvastatin 80 + ezetimibe; LDL 78."

→ Add a PCSK9 inhibitor (alirocumab or evolocumab). Goal <55 in very-high-risk.

"3 weeks after starting rosuvastatin 40, bilateral thigh aches, CK normal, TSH normal."

→ Hold statin, wait for resolution, rechallenge at lower dose or with different statin. Not PCSK9i yet.

"DM + prior MI on atorvastatin 40, LDL 65, TG 280."

→ Add icosapent ethyl 2 g BID (REDUCE-IT eligible). Not fibrate (no CV benefit when LDL controlled). Not omega-3 mixed preparation.

→ Heterozygous FH; start high-intensity statin + ezetimibe, screen first-degree relatives.

→ NPO, IV fluids, insulin infusion; once stable, fenofibrate + omega-3 + dietary restriction. Statin added later for ASCVD risk.

→ Check TSH, urine protein, A1c, medication list before escalating drugs.

→ Discontinue statin pre-conception; if needed, use bile acid sequestrant.

→ Continue statin (secondary prevention).

→ Deprescribe as part of goals of care.

Key distinction: When the stem gives you a dose of statin and a specific LDL, the answer is almost always either (a) add ezetimibe, (b) add PCSK9i, or (c) rule out secondary cause/adherence — pick based on whether they have already escalated and whether the LDL gap is plausible for the next step.

Stem 1 — "LDL still elevated on max statin":

Stem 2 — "Very-high-risk with persistent LDL despite statin + ezetimibe":

Stem 3 — "Muscle aches on statin":

Stem 4 — "Elevated TG on statin with ASCVD":

Stem 5 — "Tendon xanthomas + LDL 280":

Stem 6 — "Pancreatitis with TG 1800":

Stem 7 — "Refractory LDL":

Stem 8 — "Pregnancy planning on statin":

Stem 9 — "Dialysis patient, prior MI, on statin":

Stem 10 — "Hospice patient on statin":

One-Line Recap

In any patient with established ASCVD, the secondary-prevention lipid plan is: maximally tolerated high-intensity statin → ezetimibe → PCSK9 inhibitor (or inclisiran/bempedoic acid) to drive LDL <70 (or <55 if very-high-risk), with icosapent ethyl added when TG remains 150–499, all layered onto lifestyle, cardiac rehab, and the full ABCDE secondary-prevention bundle.

Board pearl: The Step 3 hyperlipidemia question almost never asks you to start a statin — it asks what to do next when LDL is still above goal. Master the order (statin → ezetimibe → PCSK9i) and the two thresholds (70 and 55), and you will answer the majority correctly. Then add icosapent ethyl for residual TG-driven risk and remember cardiac rehab as the highest-yield non-pharmacologic answer.

Sequencing: lifestyle + high-intensity statin → ezetimibe → PCSK9i/inclisiran → bempedoic acid (if intolerant) → icosapent ethyl (residual TG). Skip steps only for documented statin intolerance or HoFH.

Targets: LDL <70 (stable ASCVD) or <55 (very-high-risk); ApoB <65; non-HDL <85 in very-high-risk; ≥50% LDL reduction from baseline always.

Before escalating, rule out secondary causes (TSH, urine protein, A1c, medications, alcohol) and confirm adherence — these explain most "treatment failures."

Bundle, not monotherapy: aspirin, BP <130/80, smoking cessation, SGLT2i/GLP-1 RA if diabetic, cardiac rehab referral, annual flu vaccine, depression screening, and deprescribing when life expectancy is short.