Marfan syndrome, caused by pathogenic variants in FBN1, leads to progressive aortic root dilation with risk of dissection, alongside ocular and musculoskeletal complications. The central management goal is to slow aortic enlargement and prevent catastrophic events.
Medical therapy: beta-blockers and ARBs
In the landmark Pediatric Heart Network trial of over 600 children and young adults, atenolol (a beta-blocker) and losartan (an angiotensin receptor blocker) were directly compared over three years, with no significant difference between them in the rate of aortic-root dilatation — both slowed growth relative to expectation. A subsequent individual-patient-data meta-analysis confirmed that ARBs significantly reduce the rate of aortic root enlargement, by roughly half, with effects comparable and additive to beta-blockers. Accordingly, the 2022 ACC/AHA aortic disease guideline recommends maximally tolerated beta-blockers or ARBs as initial therapy, with combination therapy reasonable in higher-risk or rapidly progressing patients, and regular imaging surveillance tailored to aortic size and growth.
Surgery, activity, and genetics
Elective aortic root replacement is recommended at a diameter of about 5.0 cm, or 4.5 cm with high-risk features (rapid growth, family history of dissection); surgery before pregnancy is advised for women with a root above 4.5 cm. Ocular surveillance remains essential given the high prevalence of lens dislocation and retinal complications. Low-to-moderate-intensity exercise is now considered safe and beneficial for most patients (avoiding competitive and high-intensity activity), and FBN1 genetic testing with counseling is recommended for all patients and families.
| Modality | Role | Recommendation |
|---|---|---|
| Beta-blockers | First-line medical therapy | Reduce aortic root dilation |
| ARBs (losartan) | First-line; equivalent to beta-blockers | Combination reasonable in high-risk patients |
| Surgery | Aortic protection | Root ≥5.0 cm, or ≥4.5 cm with risk factors |
| Physical activity | Lifestyle | Low/moderate intensity encouraged |
| Genetic testing | All patients | FBN1 testing and counseling |
Further reading: atenolol vs losartan (Lacro et al., NEJM 2014); ARB individual-patient meta-analysis (Pitcher et al., Lancet 2022); 2022 ACC/AHA aortic disease guideline; 2024 ESC guidance on FBN1-related aortic disease in children.