Aortic risk low in Marfan syndrome patients with FBN1 pathogenic variant

Marfan syndrome patients carrying FBN1 pathogenic variants who receive beta-blocker therapy and who limit strenuous exercise have a low aortic risk when maximal aortic diameter is <50 mm, according to a recent study.

“The risk of type B aortic dissection is close to the remaining risk of type A aortic dissection in this population, which underlines the global aortic risk,” the investigators said.

In total, 954 patients (mean age, 23 years; 54 percent women) were eligible for the study. Of these, 142 underwent prophylactic aortic root surgery, five had type A aortic dissection, and 12 died (three noncardiovascular causes, three unknown aetiology and six postoperative) during 9.1 years of follow-up.

Risks for proven type A dissection (0.4 events per 1,000 patient-years) and for possible aortic dissection (proven aortic dissection plus death of unknown cause, 0.7 events per 1,000 patient-years) remained low in patients who were treated according to guidelines when their aortic root diameter was <50 mm.

During follow-up of 8,594 patient-years, three cases of type A aortic dissection were reported, including one in a patient with a tubular aortic diameter of 55 mm. None occurred in patients with a family history of aortic dissection. For type B aortic dissection, the risk in this population was 0.5 events per 1,000 patient-years.

This study enrolled patients with FBN1 pathogenic variant who visited a reference centre at least twice, provided they had not undergone aortic surgery or had an aortic dissection prior to their first visit. The investigators assessed aortic events (aortic surgery vs aortic dissection) and deaths during the 2 years following each patient visit. They calculated the risk as the number of events divided by the number of follow-up years.