Dyslipidaemia — SAQ

Stem

A 52-year-old man is reviewed at his GP practice. He is a smoker (20/day for 30 years) with hypertension (on amlodipine 5 mg) and a 6-year history of type 2 diabetes (HbA1c 7.6%, metformin only). His father had an MI at age 50. On examination BMI 31 kg/m², BP 146/88, waist circumference 108 cm. A fasting lipid panel shows total cholesterol 7.2 mmol/L, LDL-C 4.9 mmol/L, HDL-C 0.9 mmol/L, triglycerides 3.1 mmol/L. TSH, U&E and LFTs are normal; urine albumin:creatinine ratio 4 mg/mmol. ^[15]

Questions

a) Classify this patient's lipid abnormality and state the 2018 AHA/ACC statin-intensity recommendation that applies. (2 marks)

b) What LDL-C response is he being asked to achieve, and which risk-enhancing factors are you weighing? (3 marks)

c) Outline the stepwise pharmacological management, naming drugs, doses, and the trial evidence that supports each step. (3 marks)

d) Who should have lipoprotein(a) measured, and what threshold is used as a risk-enhancing / desirable-level cut-off? (2 marks)

Model answer

a) — Lipid pattern and risk (2 marks). This is a mixed dyslipidaemia — raised LDL-C, low HDL-C, and raised triglycerides. He is 52 with type 2 diabetes and LDL-C 4.9 mmol/L (well above 70 mg/dL / 1.8 mmol/L) plus multiple additional risk factors (smoking, hypertension, central obesity, premature family history). Under the 2018 AHA/ACC cholesterol guideline, every patient with diabetes aged 40–75 with LDL-C ≥70 mg/dL starts at least a moderate-intensity statin without calculating 10-year risk; those with multiple risk factors or aged 50–75 reasonably escalate to a high-intensity statin to cut LDL-C by ≥50%. South Asian ancestry is a risk-enhancing factor. ^[15] (1 mark pattern + 1 mark AHA diabetes/intensity with justification.)

b) — Intensity and risk factors weighed (3 marks). He should be on a high-intensity statin aiming for ≥50% LDL-C reduction (age 50–75 with diabetes plus multiple risk factors). He does not have a fetched post-ACS European under 1.4 mmol/L indication in this stem (that goal is sourced for after ACS, and under 1.0 mmol/L after a recurrent event within 2 years). Risk-enhancing factors present: diabetes, persistently high TG (≥175 mg/dL / 1.97 mmol/L), South-Asian-type atherogenic profile, and family history of premature ASCVD. ^[15][32] (1 mark ≥50% high-intensity; 1 mark not claiming an unsourced ESC diabetes-TOD 1.4 goal; 1 mark risk-enhancers.)

c) — Stepwise pharmacological management (3 marks).

• Step 1 — high-intensity statin: atorvastatin 40–80 mg once daily OR rosuvastatin 20–40 mg once daily (≥50% LDL reduction). Foundation of therapy; outcome mortality benefit proven by 4S (secondary) and WOSCOPS (primary), HPS.
• Step 2 — add ezetimibe 10 mg orally once daily if LDL remains above target (NPC1L1 cholesterol-absorption inhibitor). Outcome benefit on top of statin proven by IMPROVE-IT (post-ACS).
• Step 3 — add a PCSK9 inhibitor (alirocumab 75–150 mg SC every 2 weeks OR evolocumab 140 mg SC every 2 weeks) if still above target. ~50–60% additional LDL reduction; outcome benefit proven by FOURIER and ODYSSEY OUTCOMES.
• For the raised triglycerides (3.1 mmol/L, in the 1.5–5.6 range on a statin with ASCVD/diabetes): consider icosapent ethyl 2 g twice daily — outcome benefit proven by REDUCE-IT. If TG climbs toward 10 mmol/L, add fenofibrate (never gemfibrozil with a statin).
• Lifestyle throughout (Mediterranean diet, plant sterols 2 g/day, weight loss, smoking cessation, exercise 150 min/week). ^{[15][9][10][12]} (1 mark statin; 1 mark ezetimibe with IMPROVE-IT; 1 mark PCSK9 inhibitor with named trials + TG consideration.)

d) — Lp(a) (2 marks). The 2010 EAS consensus: measure Lp(a) once, with an isoform-insensitive assay, in intermediate- or high-CVD-risk subjects (this man has diabetes plus premature family history). Desirable level below the 80th percentile (less than 50 mg/dL); US 2018 counts ≥50 mg/dL (125 nmol/L) as a risk-enhancing factor if measured. Apo(a) is a plasminogen homologue that impairs fibrinolysis; hepatic apo(a) synthesis accounts for 90% of plasma Lp(a). ^[27][15] (1 mark who/once/assay; 1 mark 50 mg/dL threshold and why it matters.)

References10ShowHide

1. [9]Cannon CP, Blazing MA, Giugliano RP, et al. Ezetimibe Added to Statin Therapy after Acute Coronary Syndromes N Engl J Med, 2015.PMID 26039521
2. [10]Sabatine MS, Giugliano RP, Keech AC, et al. Evolocumab and Clinical Outcomes in Patients with Cardiovascular Disease N Engl J Med, 2017.PMID 28304224
3. [12]Bhatt DL, Steg PG, Miller M, et al. Cardiovascular Risk Reduction with Icosapent Ethyl for Hypertriglyceridemia N Engl J Med, 2019.PMID 30415628
4. [15]Grundy SM, Stone NJ, Bailey AL, et al. 2018 AHA/ACC Guideline on the Management of Blood Cholesterol Circulation, 2019.PMID 30586774
5. [16]Nissen SE, Lincoff AM, Brennan D, et al. Bempedoic Acid and Cardiovascular Outcomes in Statin-Intolerant Patients N Engl J Med, 2023.PMID 36876740
6. [27]Nordestgaard BG, Chapman MJ, Ray K, et al. Lipoprotein(a) as a cardiovascular risk factor: current status Eur Heart J, 2010.PMID 20965889
7. [32]Landmesser U, McGinniss J, Steg PG, et al. Achievement of ESC/EAS LDL-C treatment goals after an acute coronary syndrome with statin and alirocumab Eur J Prev Cardiol, 2022.PMID 35708715
8. [34]Krishnamurthy A, Bradley C, Ascunce R, et al. SAMSON and the Nocebo Effect: Management of Statin Intolerance Curr Cardiol Rep, 2022.PMID 35759168
9. [35]Dalugama C, Pathirage M, Kularatne SAM Delayed presentation of severe rhabdomyolysis leading to acute kidney injury following atorvastatin-gemfibrozil combination therapy: a case report J Med Case Rep, 2018.PMID 29784023
10. [38]National Institute for Health and Care Excellence Cardiovascular disease: risk assessment and reduction, including lipid modification NICE NG238, 2023.Source