Hemodynamics, anatomy, and outcomes of quadricuspid aortic valves: Multimodality imaging assessment

Background: Quadricuspid aortic valve (QAV) is a rare congenital heart disease with a limited body of literature. This retrospective cohort study investigates QAV morphology, function, and clinical outcomes. Methods: Echocardiography was used to assess valvular function. Morphological characteristics such as phenotypes, raphe, regurgitant orifice area (ROA), and aortic dilation (diameter >40 ​mm) were assessed by cardiac CT. Patients were followed up for the combined event of all-cause death and aortic valve replacement (AVR). Results: Ninety QAV patients (screened from 322385 CT scans) were included (mean age 55.2 ​± ​13.6 years, 61.1 ​% male). Isolated significant aortic regurgitation (AR) was present in 75.6 ​% of patients. The cohort was dominated by type I (four equal leaflets, 37.8 ​%) and type II (3 larger and 1 smaller leaflets, 42.2 ​%) QAV. Fused raphe was present in 26.7 ​% of patients. ROA_CT was correlated with AR severity and aortic dilation (41.1 ​%, n ​= ​37). Among patients without AVR at baseline (n ​= ​60), one died and 17 underwent AVR during a median follow-up of 35.0 months (IQR:17.3–62.8). ROA_CT was associated with an increasing risk of combined event (as a categorical variable with a cut-off of 21.4 ​mm², HR ​= ​4.25, 95%CI 1.49–12.17, p ​= ​0.007; as a continuous variable (per mm² increment), HR ​= ​1.04, 95%CI 1.01–1.07, p ​= ​0.003). Additionally, ROA_CT had incremental prognostic value when added to the AR severity model (area under the receiver-operating characteristic curve increased from 86.8 to 88.4, p ​= ​0.004). Conclusion: QAV is characterized by variable anatomy, progressive AR, concomitant cusp fusion and aortic enlargement. ROA_CT may be a potential ancillary prognostic marker in patients with QAV.