Turner Syndrome - Cardiovascular Health¶

Learning Objectives¶

Core Knowledge & Clinical Reasoning¶

[ ] Calculate and interpret Aortic Size Index (ASI = diameter/BSA; ≥2.5 = dissection risk)
[ ] Identify why ASI is preferred over absolute dimensions (smaller body size underestimates risk)
[ ] Recognize Turner-specific cardiac findings (BAV 15-30%, CoA 7-18%, PAPVR 13-15%)
[ ] Analyze aortic dissection risk factors (45,X karyotype, BAV, CoA, hypertension, pregnancy)

Management Decisions¶

[ ] Formulate imaging surveillance protocol (MRI preferred; annual if ASI >2.3)
[ ] Determine pre-pregnancy surgical threshold (ASI ≥2.5 contraindication to pregnancy)
[ ] Manage hypertension aggressively using Turner-specific BP charts (ACEi/ARB preferred)

Communication & Counseling¶

[ ] Counsel on pregnancy risks (~2% dissection risk; higher with ART) and contraindications
[ ] Explain that aortic dissection risk is 27x higher than general population (leading cause of death)
[ ] Discuss lifelong cardiovascular surveillance requirements

Systems-Based Practice¶

[ ] Coordinate comprehensive cardiac evaluation at diagnosis regardless of age
[ ] Ensure multidisciplinary Turner syndrome care (endocrinology, cardiology, genetics)
[ ] Implement high-risk pregnancy protocols when pregnancy is undertaken

Key Guidelines¶

2018 AHA Scientific Statement: Cardiovascular Health in Turner Syndrome Circ Genom Precis Med. 2018;11:e000048

2024 Turner Syndrome Clinical Practice Guidelines (Aarhus International Consensus) Eur J Endocrinol. 2024;190:G53-G151

Epidemiology¶

Incidence: ~1 in 2,500 live female births
Cardiovascular disease is leading cause of death
Aortic dissection risk: 27-40x higher than general population

Congenital Heart Disease Prevalence¶

Lesion	Prevalence
Bicuspid aortic valve	15-30%
Coarctation of the aorta	7-18%
Partial anomalous pulmonary venous return	13-15%
Elongated transverse arch	~50%
Aortic dilation	Common

Aortic Size Assessment¶

Aortic Size Index (ASI)¶

ASI = Aortic diameter (cm) / BSA (m²)

ASI	Interpretation
<2.0 cm/m²	Normal
2.0-2.5 cm/m²	Dilated
≥2.5 cm/m²	At-risk for dissection

Why Use ASI?¶

Turner patients are smaller
Absolute dimensions underestimate risk
Dissection occurs at SMALLER sizes than Marfan

Aortic Dissection Risk Factors¶

Factor	Notes
45,X karyotype (monosomy)	Highest risk
Bicuspid aortic valve
Coarctation of the aorta
Hypertension	Present in >50%
Aortic dilation (ASI ≥2.5)
Pregnancy (especially with ART)
Prior cardiac surgery

Cardiovascular Surveillance Protocol¶

Assessment	Timing
Baseline comprehensive cardiac evaluation	At diagnosis (any age)
Echo + cardiac MRI	At diagnosis
MRI of entire aorta	Every 5-10 years if normal
MRI	Annually if ASI >2.3 cm/m²
Blood pressure monitoring	Every visit
ABPM	If elevated BP

Imaging Preference¶

MRI preferred for aortic surveillance (visualizes entire aorta)
Echo limited by body habitus in adults
CT angiography if MRI not feasible

Hypertension Management¶

Extremely common (50-60% by adulthood)
Use Turner-specific growth charts for pediatric BP interpretation
Target: <90th percentile or <130/80 in adolescents
Preferred agents: ACE inhibitors or ARBs (potential aortic protection)
Consider beta-blockers if aortic dilation

Surgical Thresholds¶

Indication	Threshold
Elective surgery	ASI ≥2.5 cm/m²
Pre-pregnancy	ASI ≥2.5 cm/m²
Rapid growth	>0.5 cm/year

Pregnancy Considerations¶

HIGH RISK¶

Aortic dissection risk ~2% during pregnancy (potentially fatal)
Even higher with ART

Pre-Pregnancy Requirements¶

Cardiology consult
MRI of entire aorta
Risk discussion

Contraindicated If:¶

ASI ≥2.5 cm/m²
Aortic dilation
Severe hypertension
Prior aortic dissection

If Proceeding¶

Multidisciplinary team
Tertiary center with cardiac surgery
Frequent aortic monitoring
Cesarean section if aortic concerns

Board Pearls¶

Pearl: ASI ≥2.5 cm/m² = at-risk for dissection

MRI preferred for aortic surveillance

Pearl: Aortic dissection risk 27x higher than general population

Leading cause of death in Turner syndrome

Pearl: Pregnancy: ~2% dissection risk; contraindicated if ASI ≥2.5

Requires cardiology clearance and high-risk monitoring

Self-Assessment¶

Q1: A 16-year-old with Turner syndrome has aortic root of 2.8 cm. BSA is 1.2 m². What is her ASI and what does it indicate?

Answer

**Answer**: ASI = 2.3 cm/m²; indicates aortic dilation but below high-risk threshold **Rationale**: ASI = 2.8 / 1.2 = 2.33 cm/m². This is in the dilated range (2.0-2.5) but below the high-risk threshold of ≥2.5 cm/m². Annual MRI surveillance is indicated at this ASI level.

Q2: A 25-year-old with Turner syndrome and ASI of 2.6 cm/m² asks about pregnancy. What is your recommendation?