Coronary artery calcium testing can reveal plaque in arteries, but is underused

Original Article ↗ Hacker News Discussion ↗

Risk assessment beyond CAC

  • Many comments advocate blood-based risk markers before or alongside CAC: ApoB, Lp(a), hs‑CRP, HbA1c, eGFR, triglyceride/HDL ratio, and sometimes LDL particle assays.
  • Lp(a) is emphasized as a once‑in‑a‑lifetime, largely genetic test that can radically change risk and treatment (e.g., aspirin, more aggressive LDL targets).
  • Some argue that with ApoB and Lp(a), LDL particle size adds little extra information.
  • US posters describe easy access to self-ordered panels; UK posters describe cultural and systemic barriers to even basic lipid testing.

What CAC really measures (and doesn’t)

  • CAC detects calcified plaque (a “late-stage repair product”), not soft plaque, so it’s a lagging indicator of cumulative damage.
  • A zero score, especially under ~45, is common and not strongly predictive; age-adjusted percentiles matter.
  • Statins may increase calcification by stabilizing plaques, potentially raising CAC while lowering event risk.
  • Several warn against using a single low CAC to dismiss high LDL or to “prove” risky diets are safe.
  • Radiation exposure is nontrivial; most suggest spacing scans by years and considering echocardiogram or stress testing for follow‑up.

Anecdotes: life-saving vs anxiety-inducing

  • Multiple stories describe high CAC or CT angiography uncovering 90–95% LAD (“widowmaker”) blockages in seemingly healthy, active people, leading to timely stenting.
  • Others report incidental findings (congenital anomalies) or confirmation of low risk.
  • Some caution that more testing often finds ambiguous abnormalities, driving stress, extra procedures, and cost without clear benefit.

Statins, other therapies, and controversy

  • One view: statins are low-risk, cheap, and should be widely used even at modest 10‑year risk; benefits accumulate over decades.
  • Counterview: side effects (muscle weakness, cognitive issues, higher blood sugar) are underappreciated, and industry-driven evidence overstates LDL’s role; benefit may stem from anti‑inflammatory/plaque‑stabilizing effects rather than cholesterol lowering per se.
  • Alternatives discussed: PCSK9 inhibitors, emerging Lp(a) drugs, intensive lifestyle change, whole‑food plant-based diets, keto variants, vitamin K2, antioxidants, manganese, and microbiome-targeted approaches. Evidence is portrayed as mixed or incomplete.

Imaging options and future tech

  • Some prefer coronary CT angiography (with contrast) over plain CAC because it shows soft plaque and narrowing, but with higher radiation and contrast risks.
  • Commenters expect better CAC characterization and ECG interpretation from AI, though note data and deployment challenges.