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TAA Statistics — Quick-Reference Sheet

Last curated: 2026-08-27

Purpose. This sheet is the numbers layer of the thoracic-aortic-aneurysm knowledge base: a dense, source-locked table of published statistics on TAA and acute aortic dissection (AAD) — incidence, prevalence, natural history, surgical activity and outcomes, burden of disease, and screening yields. It complements (and deliberately does not repeat the prose of) wiki/epidemiology-and-natural-history.md; where that page argues, this sheet tabulates. Conflicting estimates are shown side by side with population, period, and method — never averaged or silently reconciled. All PMIDs were retrieved from PubMed during the 2026-08-27 curation session; portal pages were fetched the same day.

How to cite from this sheet. Always carry the PMID (or portal URL + access date) forward with the figure — never cite "the statistics sheet" as the source. Inline format: (Author Year, [PMID 12345678](https://pubmed.ncbi.nlm.nih.gov/12345678/){target="_blank" rel="noopener"}); portals: (Publisher — "Title", URL, accessed 2026-08-27). If a figure below is marked derived, it was computed from the cited source's numbers and should be re-derived, not quoted as published.


1. TAA incidence and prevalence

1.1 Clinically detected incidence

Figure Population Period Method Source
5.9 /100,000 person-yrs (age/sex-adjusted); sexes equal Olmsted County, MN (72 cases) 1951–1980 Population-based record linkage, pre-CT era; rupture occurred in 74% (53/72), and 37 of those 53 had no prior aneurysm diagnosis (Bickerstaff 1982, PMID 7147188)
10.4 /100,000 person-yrs (95% CI 8.6–12.2) — >3× the prior-era rate Olmsted County, MN (133 cases, degenerative TAA) 1980–1994 Population-based cohort; rise attributed to CT/echo/MRI diffusion (Clouse 1998, PMID 9851478)
16.3 (men) and 9.1 (women) /100,000/yr by 2002; +52% in men, +28% in women over the period Sweden, nationwide (14,229 individuals with thoracic aortic disease) 1987–2002 National healthcare registers (ICD-coded aneurysm + dissection); 78% diagnosed before death (Olsson 2006, PMID 17145990)
Pooled 5.3 /100,000/yr (95% CI 3.0–8.3); ruptured TAA 1.6 /100,000/yr (1.3–2.1) 22 population-based studies, worldwide Inception–Oct 2020 Systematic review + random-effects meta-analysis (Gouveia e Melo 2022, PMID 33705940)
9 /100,000 patient-yrs (95% CI 6.8–12.6) — severe endpoints only (ruptured or operated TAA); AD separately 15 /100,000 Malmö Diet and Cancer cohort, n=30,412, middle-aged ~16 yrs median follow-up (to ~2010s) Prospective cohort; counts only rupture/surgery, so undercounts diagnoses (Landenhed 2015, PMID 25609416)

1.2 Prevalence

Figure Population Period Method Source
0.16% (95% CI 0.12–0.20) pooled prevalence (all study designs, autopsy included) Population-based studies, worldwide to 2020 Meta-analysis (Gouveia e Melo 2022, PMID 33705940)
0.76% (95% CI 0.47–1.13) in autopsy-only studies vs 0.07% (0.05–0.11) with autopsy studies excluded — a ~10-fold gap Same meta-analysis, stratified to 2020 Autopsy vs clinical ascertainment; quantifies the undiagnosed reservoir (Gouveia e Melo 2022, PMID 33705940)
22% of thoracic aortic disease diagnosed only at death (78% before death) Sweden nationwide, 14,229 cases 1987–2002 Register + death data (Olsson 2006, PMID 17145990)

1.3 Age and sex distribution

Figure Population Period Method Source
Median age 65 (men) vs 77 (women); incidence equal in both sexes Olmsted 1951–80 1951–1980 Population-based (Bickerstaff 1982, PMID 7147188)
51% of TAAs in women; women older at recognition (mean 75.9 vs 62.8 yrs); 79% of ruptures in women Olmsted 1980–94 1980–1994 Population-based (Clouse 1998, PMID 9851478)
Male:female incidence 16.3 vs 9.1 /100,000/yr; operations rose 7-fold (men) and 15-fold (women) Sweden nationwide 1987–2002 Registers (Olsson 2006, PMID 17145990)
Acute aortic syndrome incidence 10.2 (men) vs 5.7 (women) /100,000 person-yrs; mean age 71.8; incidence increases with age Olmsted County (133 AAS cases) 1995–2015 Rochester Epidemiology Project record linkage (DeMartino 2018, PMID 30354376)

2. Acute aortic dissection

2.1 Incidence (note the ascertainment gradient: registry-only < registry+death-certificate < prospective/autopsy-inclusive)

Figure Population Period Method Source
Pooled AAD 4.8 /100,000/yr (95% CI 3.6–6.1); type A 3.0, type B 1.6; repaired 1.4; medically managed 3.4; in-hospital AAD death 1.3 /100,000/yr 33 population-based studies to Aug 2020 Systematic review + meta-analysis; incidence "varied significantly between study designs and geographical regions" (Gouveia e Melo 2022, PMID 34560218)
3.5 /100,000/yr (95% CI 2.4–4.6); TAA rupture also 3.5; AAA rupture ~9 Olmsted County (39 AAD) 1980–1994 Population-based; 85% involved ascending aorta (Clouse 2004, PMID 14959911)
6 /100,000/yr (95% CI 4–7) — prospective, includes pre-hospital deaths Oxfordshire, UK (OXVASC), pop. 92,728; 52 incident events (37 type A, 15 type B) 2002–2012 Prospective population surveillance (Howard 2013, PMID 23599348)
2.9 /100,000/yr Hungary, pop. 106,500 (84 patients incl. 18 pre-hospital deaths) 27 yrs (to ~1990s) Longitudinal population study incl. autopsy records (Mészáros 2000, PMID 10807810)
2.53 /100,000/yr (age/sex-adjusted), flat over 22 yrs Iceland, whole nation (153 ATAD) 1992–2013 Hospital discharge + autopsy + cause-of-death registries (Melvinsdottir 2016, PMID 27334108)
7.2 /100,000/yr (9.1 men, 5.4 women); decreasing in men over time Sweden, nationwide (8,057 patients; 29% dead without hospital stay) 2002–2016 National Patient Register + Cause of Death Register (Smedberg 2020, PMID 32558879)
4.2 /100,000 patient-yrs (validated cases); type A 2.2, type B 1.5 Denmark, nationwide (3,023 validated AD) 1996–2016 Register cases individually validated against medical records (Obel 2022, PMID 36321467)
AD component of AAS: 4.4 /100,000 person-yrs; IMH 1.2; PAU 2.1 (PAU rising 0.6→2.6, p=0.008); overall AAS 7.7, stable Olmsted County 1995–2015 Population-based, imaging/record/death-certificate review (DeMartino 2018, PMID 30354376)
15 /100,000 patient-yrs Malmö cohort (middle-aged, n=30,412) ~16 yrs follow-up Prospective cohort endpoints (Landenhed 2015, PMID 25609416)

2.2 Type A vs type B proportions

Figure Population Period Source
62.3% type A (of 464) IRAD, 12 referral centers 1996–1998 (Hagan 2000, PMID 10685714)
2,952 type A : 1,476 type B (67%:33%) among 4,428 enrolled IRAD, 28 centers 1995–2013 (Pape 2015, PMID 26205591)
66.0% type A (101/153) Iceland, population-based 1992–2013 (Melvinsdottir 2016, PMID 27334108)
60.5% type A : 39.5% type B (validated) Denmark, nationwide 1996–2016 (Obel 2022, PMID 36321467)
Type A 3.0 vs type B 1.6 /100,000/yr (pooled) 33-study meta-analysis to 2020 (Gouveia e Melo 2022, PMID 34560218)
Proximal:distal 5.1:1 (autopsy-inclusive) Hungary, population-based 27 yrs (Mészáros 2000, PMID 10807810)

2.3 Untreated type A early mortality — what actually supports "1–2% per hour"

Claim provenance: the figures usually cited are Hirst 1958 — "Dissecting aneurysm of the aorta: a review of 505 cases" (Medicine 1958;37:217-79, PMID 13577293) — and the review by Anagnostopoulos 1972 (Am J Cardiol 1972;30:263-73, PMID 4557973). Both PMIDs verified to exist this session, but neither has an abstract on PubMed, so their internal figures could not be re-verified this session — treat any hour-by-hour number attributed to them as [unverified at source] until the full texts are pulled.

What population data retrievable this session actually show for essentially untreated cohorts:

Figure Population Period Method Source
Of hospitalized patients: 22.7% dead ≤6 h, 33.3% ≤12 h, 50% ≤24 h, 68.2% ≤48 h; only 6/84 operated; all non-operated died; plus 21% dead before admission Hungary, population-based (84 pts) 27-yr period Records + autopsy; authors explicitly frame the cohort as approximating the natural (untreated) course (Mészáros 2000, PMID 10807810)
Arithmetic on the row above (derived): ≈3.8%/h over first 6 h, ≈2%/h averaged over first 24 h — i.e., the classic "1–2%/h" is the right order of magnitude for the first day but front-loaded Derived from Mészáros figures; re-derive before quoting (from Mészáros 2000, PMID 10807810)
In-hospital mortality 58% for type A managed medically (not operated, typically due to age/comorbidity) vs 26% surgical IRAD (464 pts) 1996–1998 Registry; medical-arm selection bias inflates the estimate as a "natural history" proxy (Hagan 2000, PMID 10685714)
48.6% of incident type A died before hospital assessment OXVASC, UK 2002–2012 Prospective population capture (Howard 2013, PMID 23599348)
21.4% of arrivals dead within 24 h; 45.2% at 30 days (all ATAD, era of surgical treatment); >half of all patients dead within 30 days of the index event Iceland, whole nation 1992–2013 Population registries incl. autopsy (Melvinsdottir 2016, PMID 27334108)

Evidence-quality verdict: the per-hour claim rests on mid-20th-century case series; the best modern population-based corroboration (Mészáros) is compatible with ~1–4%/h over the first 24–48 h in unoperated patients, but no contemporary series can ethically reproduce it, and modern cohorts (with surgery) show much lower early mortality.

2.4 Pre-hospital death fraction (why hospital registries undercount)

Figure Population Period Source
48.6% of type A dead before hospital assessment (61.1% of these women) OXVASC, prospective 2002–2012 (Howard 2013, PMID 23599348)
29% of all AD diagnosed dead without a hospital stay (2,300/8,057) Sweden nationwide 2002–2016 (Smedberg 2020, PMID 32558879)
21% dead before admission Hungary population study 27 yrs (Mészáros 2000, PMID 10807810)
17.6% dead before hospital arrival Iceland whole-nation 1992–2013 (Melvinsdottir 2016, PMID 27334108)

2.5 In-hospital / 30-day mortality by type, management, and era

Figure Population Period Method Source
Overall in-hospital 27.4%; type A surgical 26%, type A medical 58%; type B medical 10.7%, type B surgical 31.4% IRAD, 464 pts, 12 centers 1996–1998 Referral-center registry (survivors of transport only) (Hagan 2000, PMID 10685714)
Type A in-hospital 31%→22% and surgical 25%→18% across 6 enrollment eras; type B 12%→14% (NS); surgery for type A 79%→90%; TEVAR for type B 7%→31%; CT first test 46%→73% IRAD, 4,428 pts, 28 centers 1995–2013 Registry trend analysis (Pape 2015, PMID 26205591)
>7,300 cases, >51 sites, 12 countries; significant fall in type A in-hospital mortality over 20 yrs, none in type B IRAD 20-year synthesis 1996–2016 Registry review (Evangelista 2018, PMID 29685932)
30-day mortality: type A 22.0%, type B 13.9% — no significant change 1996–2016; 5-yr adjusted HR vs matched hypertensive controls 3.2 (A) and 2.1 (B) Denmark nationwide, validated cases 1996–2016 Population registers (includes non-referral deaths) (Obel 2022, PMID 36321467)
30-day case fatality 47.4% (type A reaching hospital), 13.3% (type B); 5-yr survival of 30-day survivors 85.7% / 83.3% OXVASC 2002–2012 Prospective population-based (Howard 2013, PMID 23599348)
Hospitalized 30-day mortality 26%→21% (2002–06 vs 2012–16); surgical repair within 14 days 27%→35%; women 17% vs men 12% after acute repair Sweden nationwide 2002–2016 Registers (Smedberg 2020, PMID 32558879)
Median survival 3 days (all AAD incl. unoperated); 5-yr survival 32% (vs 5% in 1951–80); operated 30-day case fatality 9% Olmsted County 1980–1994 Population-based (Clouse 2004, PMID 14959911)
Women: 32.1% of AAD; higher in-hospital mortality (adjusted OR 1.4); type A surgical mortality 32% vs 22% in men IRAD, 1,078 pts 1996– (pub. 2004) Registry (Nienaber 2004, PMID 15197151)

2.6 Misdiagnosis and diagnostic delay

Figure Population Period Source
39% initially misdiagnosed (most often as acute coronary syndrome); time to correct diagnosis 51±12 vs 15±5 h; 100% of misdiagnosed received aspirin, 85% heparin, 12% fibrinolytics; antithrombotic exposure → major bleeding 38% vs 13% 66 consecutive AAS, tertiary center, Toronto 2000–2004 Chart review
Median ED-presentation-to-diagnosis 4.3 h (IQR 1.5–24); diagnosis-to-surgery 4.3 h (2.4–24); delays associated with female sex, atypical/absent pain, normal BP, non-tertiary presentation (transfer delay-time-ratio 3.34) IRAD, 894/751 pts 1996–2007 Registry regression
Aortic dissection was the initial clinical impression in only 15% of cases (13/84) Hungary, population-based 27 yrs (Mészáros 2000, PMID 10807810)

3. Growth and natural-history numbers

3.1 Growth rates

Figure Population Period Method Source
Mean 0.12 cm/yr; mean size at presentation 5.2 cm Yale, 230 pts, 714 imaging studies 1985–1996 Serial imaging, computerized database (Coady 1997, PMID 9081092)
Mean 0.10 cm/yr (370 pts, 1,063 studies) Yale, expanded 1985–1997 Serial imaging (Coady 1999, PMID 10391339)
Mean 0.10 cm/yr (721 pts, 3,115 studies) Yale 9 yrs prospective Serial imaging (Davies 2002, PMID 11834007)
0.10 cm/yr overall: ascending 0.07, descending 0.19 Yale synthesis, 1,600 pts, 3,000 imaging studies to 2002 Database synthesis (Elefteriades 2002, PMID 12440685)
Range 0.2–4.2 mm/yr across studies; ascending/arch 0.2–2.8, descending/TAAA 1.9–3.4 mm/yr; studies "generally low" quality, methods heterogeneous Systematic review, 11 studies, n=1,383 to Apr 2015 SIGN-graded systematic review (Oladokun 2016, PMID 26947541)
Familial TAA 0.21 cm/yr vs sporadic 0.16 vs Marfan 0.1 (p<0.01) Yale, 520 interviewed probands to 2006 Pedigree + serial imaging (Albornoz 2006, PMID 16996941)

Consistent growth accelerators across studies: larger current size, distal location, Marfan syndrome, bicuspid aortic valve; chronic dissection and COPD implicated (Oladokun 2016, PMID 26947541).

3.2 Size-dependent risk (Yale program) and replications

Figure Population Period Source
Median size at rupture/dissection 6.0 cm (ascending) / 7.2 cm (descending); >6.0 cm: +32.1 percentage-points complication probability (ascending); >7.0 cm: +43.0 (descending) Yale, 230 pts 1985–1996 (Coady 1997, PMID 9081092)
≥6.0 cm: +25.2 points (ascending); ≥7.0 cm: +37.3 (descending); median complication sizes 5.9/7.2 cm Yale, 370 pts 1985–1997 (Coady 1999, PMID 10391339)
Yearly rates at >6 cm: rupture 3.7%/yr; rupture-or-dissection 6.9%/yr; death 11.8%/yr; any 15.6%/yr; odds of rupture ×27 above 6 cm; unoperated 5-yr survival 54% Yale, 721 pts (570 analyzable; 304 dissection-free) 9 yrs (Davies 2002, PMID 11834007)
Hinge points 6.0 cm (ascending) / 7.0 cm (descending); cumulative rupture-or-dissection risk on reaching them 31% / 43%; yearly at ≥6 cm: rupture 3.6%, dissection 3.7%, death 10.8%, any 14.1% Yale synthesis, 1,600 pts to 2002 (Elefteriades 2002, PMID 12440685)
Aortic size index (cm/m²): <2.75 → ~4%/yr; 2.75–4.24 → ~8%/yr; >4.25 → ~20%/yr (rupture/dissection/death) Yale, 410 pts with BSA to 2005 (Davies 2006, PMID 16368358)
Aortic height index (cm/m): ≤2.43 / 2.44–3.17 / 3.21–4.06 / ≥4.1 → 4% / 7% / 12% / 18% average yearly complication risk; AHI model fit modestly superior to ASI Yale, 780 pts to 2017 (Zafar 2018, PMID 29395211)
Moderate dilatation (4.0–5.5 cm, nonsyndromic): dissection/rupture 0.1%/patient-yr; 5-yr risk 0.4% @45 mm, 1.1% @50 mm, 2.9% @55 mm (with elective repair per practice) Asan Medical Center echo database, 4,654 adults, 14,432 patient-yrs to ~2015 (Kim 2016, PMID 27609684)
Mean aortic diameter at type A dissection 5.3 cm; 59% dissect at <5.5 cm, 40% at <5.0 cm; hypertension (OR 2.17) predicts dissection at smaller size; Marfan dissect larger (OR 14.3) IRAD, 591 type A 1996–2005 (Pape 2007, PMID 17709637)
Population denominator: mean ascending aorta 3.2±0.4 cm; 79.2% <3.5 cm, 0.22% ≥4.5 cm; relative risk of dissection 0.055 (<3.5), 2.5 (3.5–3.9), 4.9 (4.0–4.4), 346.8 (≥4.5); ≥4.5 vs <3.5 cm: ×6,305 MRI reference population n=3,573 + dissection distribution published 2015 (Paruchuri 2015, PMID 25997607)

3.3 Untreated-vs-treated survival anchors

Figure Population Period Source
Untreated historical 5-yr survival 13% (7% with dissection, 19% without); 74% rupture Olmsted, pre-CT era 1951–1980 (Bickerstaff 1982, PMID 7147188)
5-yr rupture risk by size at recognition: <4 cm 0%, 4–5.9 cm 16%, ≥6 cm 31%; cumulative rupture 20% at 5 yrs; 5-yr survival 56% (vs 19% prior era) Olmsted 1980–1994 (Clouse 1998, PMID 9851478)
Acute mortality: 41% ruptured TAA, 39% AD, 34% ruptured AAA Malmö cohort endpoints ~16-yr follow-up (Landenhed 2015, PMID 25609416)
Elective preemptive repair "restored life expectancy to normal" (vs 54% 5-yr unoperated survival) Yale 9 yrs (Davies 2002, PMID 11834007)
AAS 5/10/20-yr mortality 39%/57%/91% vs 18%/41%/66% in matched controls (adjusted mortality HR 2.1); excess concentrated in first 90 days Olmsted AAS 1995–2015 (DeMartino 2018, PMID 30354376)

4. Surgical activity and outcomes

Figure Population Period Method Source
45,894 proximal aortic operations captured in 5.5 yrs: 12,702 root, 22,048 supracoronary ascending, 6,786 ascending+arch, 4,358 root+arch STS Adult Cardiac Surgery Database, North America 2004–2009 Registry query (Williams 2012, PMID 22958956)
2,455 thoracic aortic operations nationwide; operations rose 7-fold (men) / 15-fold (women) over 16 yrs Sweden 1987–2002 National registers (Olsson 2006, PMID 17145990)
Thoracic aortic procedures per year doubled; total UK cardiac surgery 534,067 procedures, overall in-hospital mortality 4.0%→2.8% UK NACSA (all cardiac surgery) 2002–2016 Mandatory national audit (Grant 2021, PMID 36003724)
AD admissions 6,980→8,875/yr; type A open repairs 1,143→2,130/yr; TEVAR admissions 96 (2005)→1,130 (2012); type B open repair and medical-management volumes flat US National Inpatient Sample (weighted) 2003–2012 Administrative (ICD-9) (Zimmerman 2016, PMID 27183856)
25,462 ATAAD repairs (STS) over 13 yrs; arch involved in 46% of repairs (range 38.6–52.6% across 9 US regions) STS ACSD 2004–2016 Registry (Helder 2020, PMID 31400338)
TEVAR uptake for type B in IRAD: endovascular management 7%→31% IRAD 1995–2013 Registry (Pape 2015, PMID 26205591)
Medicare descending TAA repairs: 12,573 open vs 2,732 TEVAR US Medicare 1998–2007 Claims (Goodney 2011, PMID 22104552)

4.2 Elective proximal (root/ascending/arch) repair mortality

Figure Population Period Method Source
Elective operative mortality 3.4%; nonelective 15.4%; adjusted OR emergent-vs-elective 5.9 (95% CI 5.3–6.6) STS ACSD, 45,894 ops 2004–2009 Registry risk model (c=0.81) (Williams 2012, PMID 22958956)
Ascending/arch 2.5%; descending/TAAA 8% (referral-center benchmark used in the hinge-point risk/benefit arithmetic) Yale to 2002 Single-center series (Elefteriades 2002, PMID 12440685)
Elective 9.0% vs emergency 21.7% (historical era) Yale, 136 operated of 230 1985–1996 Single-center (Coady 1997, PMID 9081092)
Elective arch repair: 30-day mortality 5.3%, permanent neurologic dysfunction 5.3% (791 consecutive; antegrade cerebral perfusion protective, OR 0.37) St. Antonius, Netherlands 2005–2015 Single high-volume center (Cefarelli 2017, PMID 28760465)
Open descending/TAAA: elective 30-day 3.1% (DTA) and 9.9% (TAAA); nonelective 17.9%; paraplegia 0% (DTA) / 3.3% (TAAA) Liverpool, UK, 430 consecutive 1998–2019 Single specialist center (Harky 2021, PMID 33068762)
30-day mortality after operation 16% (all indications, incl. acute); 1/5/10-yr survival 92%/77%/57%; 10-yr reoperation 7.8% Sweden nationwide, 2,455 ops 1987–2002 Registers (Olsson 2006, PMID 17145990)

4.3 Acute type A repair mortality and era trend

Figure Population Period Source
Surgical mortality 25%→18% across eras (in-hospital 31%→22%) IRAD 1995–2013 (Pape 2015, PMID 26205591)
30-day mortality 18.9% (ascending-only) vs 19.8% (+arch); earlier operative year independently predicted death STS ACSD, 25,462 repairs 2004–2016 (Helder 2020, PMID 31400338)
Operative mortality 21.6% overall; national trend 23% (1998–2000)→19% (2005–2008) US NIS, 5,184 pts 2003–2008 (Chikwe 2013, PMID 23562465)
In-hospital mortality 21.5% (low-volume) → 11.6% (high-volume tertile); overall trend down as volumes rose US NIS, 25,231 repairs 2005–2014 (Dobaria 2020, PMID 32507629)
In-hospital mortality 15.3% (7,805 weighted repairs); age 71–80 OR 5.3, >80 OR 6.8 vs ≤40 US NIS 2017–2018 (Catalano 2022, PMID 36172443)
GERAADA 30-day mortality 16.9% (2,137 pts); mortality-corrected permanent neurologic dysfunction 10.0%; circulatory arrest >30 min without cerebral perfusion: 31.4% mortality vs 21.4% with Germany, GERAADA 4-yr accrual window (Krüger 2013, PMID 23657546)
GERAADA 30-day mortality 16.3% (women) vs 16.6% (men), 3,380 pts; women 37%, older (65.5 vs 59.2 yrs) Germany, 56 centers 2006–2015 (Rylski 2021, PMID 31926709)
Marfan vs matched non-Marfan 30-day mortality 19.5% vs 20.1% (NS) GERAADA, 3,385 pts (117 Marfan) 2006–2015 (Farag 2023, PMID 34446289)
UK: death and/or stroke 27.7% after TAAD repair (1,929 pts); DHCA-only vs unilateral ACP OR 5.35 for death/CVA UK NACSA 2011–2018 (Benedetto 2021, PMID 33963362)

4.4 Volume–outcome relationships

Figure Population Period Source
AAD repair: surgeon <1 case/yr → 27.5% mortality vs ≥5/yr → 17.0% (OR 1.78); institution ≤3/yr → 27.4% vs >13/yr → 16.4% US NIS, 5,184 2003–2008 (Chikwe 2013, PMID 23562465)
ATAAD repair at low- vs high-volume hospitals: adjusted OR 2.10 for mortality; all complication classes higher at low volume US NIS, 25,231 2005–2014 (Dobaria 2020, PMID 32507629)
Elective root replacement (Medicare, 4,629 pts, 1,276 surgeons, 718 hospitals): nonlinear volume effect; high-volume hospitals (≥4.5 cases/yr) lower stroke (HR 0.51), MI (0.49), dialysis (0.44), reoperation (0.48); high-volume surgeons ≥9/yr similar pattern US Medicare 2009–2014 (Brown 2021, PMID 33982345)
England: 6-month treatment rates for thoracic aortic disease varied 7.6–31.5% across counties; risk-adjusted 6-month mortality in untreated patients 19.4–36.3%; higher-volume regional units had significantly lower risk-adjusted mortality England HES (24,548) + NACSA (8,058) to 2015 (Bottle 2017, PMID 28292748)
2022 ACC/AHA guideline adds "increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise" US guideline 2022 (Isselbacher 2022, PMID 36334952)

4.5 Open vs endovascular (descending TAA)

Figure Population Period Source
Perioperative mortality intact TAA: TEVAR 6.1% vs open 7.1% (p=0.07); ruptured: 28% vs 46% (p<0.0001); but 5-yr survival worse in TEVAR-selected pts (62% vs 72%) — selection of sicker patients to TEVAR US Medicare, 15,305 repairs 1998–2007 (Goodney 2011, PMID 22104552)
In-hospital mortality: type A open repair 20.5%→14.8%; type B open 18.0%→14.3%; TEVAR ~7.9% flat; medical 17.5%→13.9% US NIS (dissection admissions) 2003–2012 (Zimmerman 2016, PMID 27183856)

5. Global and national burden

Definition caveat (explicit): GBD models a single "aortic aneurysm" cause. The foundational GBD mortality paper analyzes "aortic dissection and aneurysms" merged into one AA cause (Sampson 2014, PMID 25432126), and the GBD 2019 burden analysis likewise reports one aortic-aneurysm cause with no thoracic/abdominal split (Wang 2022, PMID 35711350). No published TAA-specific share of GBD aortic-aneurysm deaths was found in this session's searches — treat any "TAA share of GBD deaths" claim as unsourced. (An IHME factsheet fetch was attempted and blocked, HTTP 403; healthdata.org, attempted 2026-08-27.)

Figure Population Period Method Source
Global AA death rate 2.49 /100,000 (1990) → 2.78 (2010); highest regional rates Australasia (8.82→8.38) and Western Europe (7.69→7.68); men 3.40 vs women 2.15 (2010); death rates rising faster in developing regions (+0.71 vs +0.22 median relative change) GBD 2010, 21 world regions 1990–2010 Cause-of-death ensemble modeling (Sampson 2014, PMID 25432126)
Absolute AA deaths +82.1% and DALYs +67% (1990→2019), but age-standardized death rate falling (EAPC −1.34, 95% CI −1.46 to −1.22) and DALY rate falling (EAPC −1.06); leading attributable risks: smoking, high systolic BP; burden concentrated in high-SDI regions, age-dependent, male-predominant GBD 2019, 204 countries 1990–2019 GBD 2019 systematic analysis (Wang 2022, PMID 35711350)
US: 289,971 aortic aneurysm + dissection deaths, adults ≥25 (≈11,600/yr average — derived); age-adjusted mortality declining, AAPC −3.73% (95% CI −4.33 to −3.14); higher burden and slower decline in men and non-Hispanic Black adults; small rise in age 35–44 (AAPC +1.04%); Midwest and nonmetropolitan excess US, CDC WONDER 1999–2023 Death-certificate database, joinpoint regression (Lv 2026, PMID 41776414)
US AA/AD mortality decline 1999–2020 disproportionately favors males and White decedents; male–female mortality gap widening 0.57 /100,000/yr US, CDC WONDER 1999–2020 Death certificates, linear regression (Azuma 2025, PMID 39951651)
US: 21,221 AD-related deaths with hypertension as underlying cause; age-adjusted rate rose 1999–2006 (APC +3.87), fell sharply 2006–2009 (−18.95), rose again 2009–2019 (+3.52) US, CDC WONDER multiple-cause files 1999–2019 Death certificates, joinpoint (Tabassum 2025, PMID 40365225)
In-hospital AAD death rate 1.3 /100,000 population/yr (pooled); geography a significant source of heterogeneity 33 population studies to 2020 Meta-analysis (Gouveia e Melo 2022, PMID 34560218)
National case-mortality anchors for cross-checking coded death data: Denmark 30-day 22.0% (A) / 13.9% (B), stable 1996–2016; Sweden hospitalized 30-day 26%→21% (2002–2016) Denmark; Sweden 1996–2016; 2002–2016 Validated national registers (Obel 2022, PMID 36321467; Smedberg 2020, PMID 32558879)

6. Screening and family statistics

Figure Population Period Method Source
21% of TAA probands have a first-degree family member with arterial aneurysm Yale pedigrees to 2002 Family-history analysis (Elefteriades 2002, PMID 12440685)
21.5% of non-Marfan TAA patients show a familial pattern; inheritance autosomal dominant in 76.9% (variable penetrance); familial probands younger than sporadic (58.2 vs 65.7 yrs; Marfan 27.4); among affected relatives 66.5% TAA, 24.9% AAA, 8.6% cerebral/other Yale, 520 interviewed TAA patients (88 familial pedigrees) to 2006 Structured pedigree study (Albornoz 2006, PMID 16996941)
Screening relatives of nonsyndromic TAD probands finds newly affected individuals in 33% of first-, 24% of second-, 15% of third-degree relatives; a specific gene mutation found in 25% of screened families; no studies of screening-test predictive accuracy or cost-effectiveness Systematic review: 53 studies, 2,696 relatives screened to Dec 2017 Systematic review (genetic 49%, imaging 11%, both 40% of studies) (Mariscalco 2018, PMID 30371227)
Pathogenic/likely-pathogenic variant in 4.9% of 1,025 unrelated TAAD cases on a 15-gene panel; ~half of variants in nonsyndromic patients without family history; FBN1 the most-hit gene (25/49 variants); yield rises with syndromic features, youth, family history, ascending involvement Mixed familial+sporadic UK/Yale cohort published 2018 Targeted NGS panel (Weerakkody 2018, PMID 29543232)
Yield 36% when testing is driven by clinical suspicion at a referral center; 57.1% if a known familial mutation exists; 42.3% in root/ascending aneurysm-dissection phenotype 96 referred, 75 tested; academic center 2010–2015 Retrospective cohort, panel + single-gene testing (Hicks 2018, PMID 29510914)
Guideline posture: 2022 ACC/AHA guideline covers "genetic evaluation and family screening" as a core management element for aortic disease US practice guideline 2022 Guideline (Isselbacher 2022, PMID 36334952)

Interpretation note: the familial-proportion figures (~21%) come from pedigree interview studies at a referral center; the mutation-yield figures (4.9% panel-wide vs 36% suspicion-driven) differ because of cohort selection — present both, never blend.


7. Data infrastructure appendix — the registries behind the numbers

Registry / dataset What it is Era Scale (verified) Access / key description source
IRAD — International Registry of Acute Aortic Dissection Consecutive AAD cases at large referral centers; presentation, imaging, management, in-hospital and post-discharge outcomes 1996– 58 centers in 13 countries (site, 2026); >7,300 cases, >51 sites, 12 countries as of 2018 publication (IRAD — "International Registry of Acute Aortic Dissection", https://www.iradonline.org/, accessed 2026-08-27; Evangelista 2018, PMID 29685932; founding cohort: Hagan 2000, PMID 10685714)
GERAADA — German Registry for Acute Aortic Dissection Type A Multicenter German-speaking registry of operated ATAAD; intraoperative strategy detail (perfusion, arrest times) 2006– 56 centers; 3,380–3,385 patients accrued Jul 2006–Jun 2015 (Rylski 2021, PMID 31926709; Krüger 2013, PMID 23657546; Farag 2023, PMID 34446289)
STS ACSD — Society of Thoracic Surgeons Adult Cardiac Surgery Database US/North-American clinical registry of adult cardiac surgery; risk models, proximal aortic and dissection modules 1989– ~8.5 million adult cardiac procedure records; >3,500 participating physicians; STS states ~95% coverage of US adult cardiac surgery (STS — "STS National Database", https://www.sts.org/sts-national-database, accessed 2026-08-27; aortic analyses: Williams 2012, PMID 22958956; Helder 2020, PMID 31400338)
UK NACSA — National Adult Cardiac Surgery Audit (NICOR/NCAP) Mandatory UK-wide audit of all adult cardiac surgery incl. thoracic aortic 2002 analyses onward (audit older) 534,067 procedures 2002–2016; one of 10 domains of NICOR's National Cardiac Audit Programme (NICOR — "National Institute for Cardiovascular Outcomes Research", https://www.nicor.org.uk/, accessed 2026-08-27; Grant 2021, PMID 36003724; TAAD subset: Benedetto 2021, PMID 33963362)
GenTAC (legacy) US NHLBI longitudinal registry + biorepository of genetically triggered TAA (Marfan, Loeys-Dietz, vEDS, Turner, BAV, familial TAAD) Oct 2006–Sep 2016 (closed; legacy biospecimens) >3,500 participants; aortic tissue, plasma, DNA, cell lines; open requests via BioLINCC (NHLBI BioLINCC — "GenTAC", https://biolincc.nhlbi.nih.gov/studies/gentac/, accessed 2026-08-27; design: Eagle 2009, PMID 19185640)
NIS/HCUP — National Inpatient Sample All-payer US inpatient administrative database; source of national volume/mortality trend estimates (with ICD-coding caveats) 1988–2023 ~20% stratified sample of US community-hospital discharges; ~7 million stays/yr unweighted (~33+ million weighted); AHRQ-sponsored; 2012 redesign to discharge-level sampling (AHRQ HCUP — "NIS Overview", https://hcup-us.ahrq.gov/nisoverview.jsp, accessed 2026-08-27; example aortic uses: Chikwe 2013, PMID 23562465; Zimmerman 2016, PMID 27183856)
Population register systems Sweden (National Patient + Cause of Death Registers), Denmark (National Patient Registry with case validation), Rochester Epidemiology Project (Olmsted), OXVASC (prospective population surveillance) varies Sweden 8,057 AD 2002–16; Denmark 3,023 validated AD 1996–2016; Olmsted linkage 1995–2015; OXVASC pop. 92,728 (Smedberg 2020, PMID 32558879; Obel 2022, PMID 36321467; DeMartino 2018, PMID 30354376; Howard 2013, PMID 23599348)

8. Known conflicts and caveats — the biggest statistical disagreements

  1. AAD incidence spans ~2.5–7.2 /100,000/yr depending on ascertainment. Registry/hospital-only designs (Iceland 2.53; Olmsted 3.5) sit far below designs adding death-certificate/autopsy capture (Sweden 7.2 with 29% never hospitalized; OXVASC 6 with 48.6% pre-hospital type A deaths). The meta-analytic 4.8 is a mix of both designs (Melvinsdottir 2016, PMID 27334108; Clouse 2004, PMID 14959911; Smedberg 2020, PMID 32558879; Howard 2013, PMID 23599348; Gouveia e Melo 2022, PMID 34560218).
  2. TAA prevalence differs 10-fold by method (0.07% clinical-only vs 0.76% autopsy-based): the silent-disease reservoir means clinically ascertained incidence tracks imaging intensity, not biology — the Olmsted tripling (5.9→10.4) coincides with cross-sectional imaging diffusion (Gouveia e Melo 2022, PMID 33705940; Bickerstaff 1982, PMID 7147188; Clouse 1998, PMID 9851478).
  3. "Is type A mortality improving?" depends on the denominator. IRAD (referral centers, transported survivors) shows in-hospital mortality falling 31%→22% (Pape 2015, PMID 26205591), while validated nationwide Danish data show 30-day mortality flat at 22.0% over 1996–2016 (Obel 2022, PMID 36321467). Referral-bias, survivorship, and era-of-enrollment effects have not been reconciled.
  4. ICD-coded databases overstate dissection counts. In Denmark only 60.2% of registered AD diagnosis codes survived record validation (Obel 2022, PMID 36321467) — a direct caution for NIS/CDC WONDER trend work, which is coding-based (Chikwe 2013, PMID 23562465; Lv 2026, PMID 41776414).
  5. The "1–2% per hour" untreated type A figure is folklore-grade in provenance (Hirst 1958, PMID 13577293; Anagnostopoulos 1972, PMID 4557973 — neither abstract retrievable), but order-of-magnitude compatible with the one modern population series that approximates an untreated cohort (50% dead by 24 h after admission; Mészáros 2000, PMID 10807810). It should be quoted as a characterization of untreated historical natural history, not of contemporary managed patients.
  6. Growth rates vary 20-fold across studies (0.2–4.2 mm/yr) with low study quality and non-standardized measurement; segment (ascending 0.07 cm/yr vs descending 0.19), etiology, and measurement technique explain much of the spread — single "TAA growth rate" numbers are meaningless without segment/etiology (Oladokun 2016, PMID 26947541; Elefteriades 2002, PMID 12440685).
  7. Yearly rupture/dissection rates by size come from one referral center (Yale) with censoring at operation; the ASI/AHI risk bands are internal re-analyses of overlapping cohorts, and no external population-level replication of the 6.0/7.0 cm hinge points was found this session (Davies 2002, PMID 11834007; Davies 2006, PMID 16368358; Zafar 2018, PMID 29395211).
  8. GBD "aortic aneurysm" merges thoracic + abdominal disease (and dissection deaths) into one cause, so global TAA-specific deaths/DALYs are strictly unknown; national vital statistics (CDC WONDER) similarly pool aneurysm subtypes in most published analyses (Sampson 2014, PMID 25432126; Wang 2022, PMID 35711350; Lv 2026, PMID 41776414).
  9. The size paradox is a denominator artifact, not a contradiction: 59% of type A dissections occur below 5.5 cm (Pape 2007, PMID 17709637) while per-person risk at those sizes is low (0.1%/patient-yr at 4.0–5.5 cm; Kim 2016, PMID 27609684) because small aortas vastly outnumber large ones (Paruchuri 2015, PMID 25997607). Quoting either half alone misleads.

Source key (all PMIDs verified against PubMed 2026-08-27)

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Portal pages fetched 2026-08-27: IRAD (https://www.iradonline.org/), STS National Database (https://www.sts.org/sts-national-database), NICOR (https://www.nicor.org.uk/), HCUP NIS Overview (https://hcup-us.ahrq.gov/nisoverview.jsp), NHLBI BioLINCC GenTAC (https://biolincc.nhlbi.nih.gov/studies/gentac/). IHME GBD factsheet fetch attempted and blocked (HTTP 403).