Quadricuspid Aortic Valve

44-year-old woman was referred to our hospital for aortic valve replacement. She had previously been diagnosed with symptomatic moderate-to-severe aortic insufficiency by surface echocardiography and aortic root angiography (Fig. 1). Intraoperative transesophageal echocardiography (Figs. 2 and 3) showed mild thickening of 4 symmetric aortic valve cusps, a small rectangular central regurgitant orifice, and significant aortic insufficiency due to central leaflet tip malcoaptation. The systolic cusp straightening was normal. A large left main coronary artery originated unusually low in the aortic root near the posterior margin of the left coronary cusp, producing a “4-leaf clover” appearance (Fig. 2). Direct surgical inspection (Fig. 4) confirmed mild thickening of the leading edges of the 4 cusps. The valve was successfully replaced with a low-profile St. Jude Regent® mechanical prosthesis (St. Jude Medical; St. Paul, Minn) in order to avoid interference with the “low” left coronary ostium.

Fig. 1 Aortic root angiography (left anterior oblique projection) reveals 4 aortic valve cusps, a small right coronary artery (single arrow), and aortic insufficiency jet (double arrows).

Real-time motion images are available at texasheartinstitute.org/Holm314.html.

Fig. 2 Intraoperative transesophageal echocardiogram (short-axis view during diastole) of the quadricuspid aortic valve's “4-leaf clover” appearance. The left coronary artery is indicated by double arrows, and the small right coronary ostium, barely visible, is shown by a single black arrow. Two noncoronary cusps are symmetrically located on each side of the adjacent interatrial septum (single white arrow). Note the rectangular central regurgitant orifice.

LA = left atrium, RA = right atrium, RVOT = right ventricular outflow tract

Real-time motion images are available at texasheartinstitute.org/Holm314.html.

Fig. 3 Intraoperative transesophageal echocardiogram (long-axis view) of the quadricuspid aortic valve and ascending aorta (Ao) during diastole, with incomplete cusp closure.

LA = left atrium

Real-time motion images are available at texasheartinstitute.org/Holm314.html.

Fig. 4 Quadricuspid aortic valve cusps from the surgical aortotomy view. Note mild thickening of the cusps' edges and tips.

Comment

An isolated quadricuspid aortic valve is a rare clinical finding. The 1st known case report was written by Balington in 1862.¹ Since then, there have been anywhere from 129 to 186 case reports, according to recent review articles.^2,3 The prevalence by historical autopsy review is approximately 0.008%.⁴ A modern echocardiography database review showed the prevalence to be somewhat higher, depending on the years reviewed (0.013%–0.043%).⁵ Quadricuspid aortic stenosis is rare,³ but significant aortic insufficiency due to cusp malcoaptation is common with this lesion.^3,5,6 Valve replacement is frequently required in the 5th or 6th decade of life,⁷ as was the case in our patient. According to the Hurwitz and Roberts classification of quadricuspid aortic valves,⁸ our case represents the most common “type A” variant, with 4 equal cusps.