Influence of moderate prosthesis–patient mismatch on long-term outcomes in patients with severe aortic stenosis with paradoxically reduced gradients against the background of reduced stroke volume after aortic valve replacement with a biological prosthesis: retrospective comparative study

Abstract

OBJECTIVE: Our aim was to evaluate the impact of moderate prosthesis–patient mismatch on long-term results after aortic valve replacement in patients with severe aortic stenosis with paradoxically reduced gradients against the background of a reduced stroke volume of the left ventricle. MATERIALS AND METHODS: We analyzed data from 88 patients with symptomatic severe aortic stenosis meeting the criteria: paradoxically reduced gradients against the background of a reduced stroke volume of the left ventricle. Patients were divided into 2 groups: Group 1 (n=42, mean age 67±4 years) with paradoxically reduced gradients against the background of reduced stroke volume of the left ventricle, with a moderate patient–prosthesis mismatch; Group 2 (n=46, mean age 68±6 years) with paradoxically reduced gradients against the background of reduced stroke volume of the left ventricle, without patient–prosthesis discrepancy. All patients underwent transthoracic echocardiographic evaluation. RESULTS: The average follow-up period was 84 (quarterly interval 75±98) months, during the follow-up period 35 (40%) deaths were registered. There were no significant differences in in-hospital mortality: 2 (4.7%) and 2 (4.3%), respectively (p=0.2). In the long-term follow-up period, there was a significant difference in survival and hospitalization rates for exacerbation of heart failure between patients with and without patient–prosthesis mismatch: 46 and 71%, 37 and 72%, respectively (p0.001). In the long-term follow-up period, patients with patient–prosthesis mismatch showed a trend towards slower regression of left ventricle mass and left atrial volume, as well as a slower recovery of global longitudinal deformation of the left ventricle and exercise tolerance compared with patients without patient–prosthesis mismatch. There were no significant differences in the incidence of stroke (90% and 91%; p=0.7). According to the results of Cox regression, the left ventricular stroke volume index and the aortic valve effective orifice area index were independent predictors of lethal events and the risk of hospitalization for exacerbation of heart failure. CONCLUSION: Moderate patient–prosthesis mismatch in patients with paradoxically reduced gradients associated with reduced left ventricular stroke volume is independently associated with increased mortality and increased hospitalization for exacerbations of heart failure.

Keywords

• aortic stenosis
• patient–prosthesis mismatch
• biological prosthesis
• paradoxically low stroke volume
• low gradients