Evidence Of Subannular And Left Ventricular Morphological Differences In Patients With Bicuspid Versus Tricuspid Aortic Valve Stenosis: Magnetic Resonance Imaging-Based Analysis

OBJECTIVES: Prospective analysis of left ventricular (LV) morphological/functional parameters in patients with bicuspid versus tricuspid aortic valve (TAV) stenosis undergoing aortic valve replacement (AVR) surgery.METHODS: A total of 190 consecutive patients with BAV (n = 154) and TAV stenosis (n = 36) (mean age 61 +/- 8 years, 65% male) underwent AVR +/- concomitant aortic surgery from January 2012 through May 2015. All patients underwent preoperative cardiac magnetic resonance imaging in order to evaluate: (i) left ventricular outflow tract (LVOT) dimensions, (ii) length of anterior mitral leaflet (AML), (iii) end-systolic and end-diastolic LV wall thickness, (iv) LV area, (v) LV end-systolic and end-diastolic diameters (LVESD, LVEDD), (vi) LV end-diastolic and endsystolic volumes (LVEDV, LVESV) and (vii) maximal diameter of aortic root. These parameters were compared between the two study groups.RESULTS: The LVOT diameter was significantly larger in BAV patients (21.7 +/- 3mm in BAV vs 18.9 +/- 3mm in TAV, P < 0.001). Moreover, BAV patients had significantly longer AML (24 +/- 3mm in BAV vs 22 +/- 4mm in TAV, P = 0.009). LVEDV and LVESV were significantly larger in BAV patients (LVEDV: 164.9 +/- 68.4ml in BAV groups vs 126.5 +/- 53.1 ml in TAV group, P = 0.037; LVESV: 82.1 +/- 57.9ml in BAV group vs 52.9 +/- 25.7ml in TAV group, P = 0.008). A strong linear correlation was found between LVOT diameter and aortic annulus diameter in BAV patients (r= 0.7, P < 0.001), whereas significantly weaker correlation was observed in TAV patients (r= 0.5, P = 0.006, z = 1.65, P= 0.04). Presence of BAV morphology was independently associated with larger LVOT diameters (OR 9.0, 95% CI 1.0-81.3, P = 0.04).CONCLUSIONS: We found relevant differences in LV morphological/functional parameters between BAV and TAV stenosis patients. Further investigations are warranted in order to determine the cause of these observed differences.