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Davies RR, Gallo A, Coady MA, Tellides G, Botta DM, Burke B, Coe MP, Kopf GS, Elefteriades JA. Novel measurement of relative aortic size predicts rupture of thoracic aortic aneurysms. Ann Thorac Surg. 2006;81(1):169-77. PMID 16368358

One-paragraph summary

From 805 serially followed Yale TAA patients, 410 with body-surface-area data (257 M, 153 F) were analyzed to test whether aortic size relative to the patient outperforms absolute diameter. The authors defined the aortic size index (ASI = aortic diameter [cm] / BSA [m²]). Increasing ASI predicted rupture (p = 0.0014) and the combined endpoint of rupture, dissection, or death (p < 0.0001), and stratified patients into three risk bands: ASI <2.75 cm/m² ≈ 4%/yr, 2.75–4.24 cm/m² ≈ 8%/yr, ≥4.25 cm/m² ≈ 20%/yr of adverse events. Conclusion: relative aortic size matters more than absolute size for complication prediction.

Key findings

  • ASI bands: <2.75 cm/m² → low risk (~4%/yr); 2.75–4.24 → moderate (~8%/yr); ≥4.25 → high (~20%/yr).
  • Relative size outperformed absolute diameter for predicting rupture and combined endpoints — directly relevant to small-statured patients (disproportionately women) whose aortas dissect "small" by absolute criteria.
  • Note within the Yale program: the same group later showed height alone (aortic height index) suffices, sparing the weight/BSA calculation, with four AHI bands carrying ~4/7/12/18%/yr risk (Zafar 2018, PMID 29395211).

Limitations

  • BSA available in only 410/805 patients — potential selection bias.
  • Single-center referral cohort; yearly-rate estimates carry wide confidence bounds and censoring at elective operation.
  • BSA-indexing embeds weight, which contributes little to normal aortic size (the rationale for the later height-index revision; Zafar 2018, PMID 29395211); obesity can lower ASI and mask risk.
  • Not externally validated in this paper; validation and guideline adoption came later.

Why it matters

This is the paper that moved TAA risk assessment beyond one-size-fits-all diameters, seeding indexed thresholds (ASI, then AHI, and cross-sectional-area/height ratios) now embedded in guideline care for small-statured and syndromic patients. It partially answers the aortic size paradox: an absolutely small aorta can be relatively large for its owner. See wiki/risk-stratification-and-size-thresholds.md for the downstream framework.

Cited by wiki pages

  • anatomy-and-classification
  • epidemiology-and-natural-history