Predictive value of left ventricular diastolic chamber stiffness in patients with severe aortic stenosis undergoing aortic valve replacement

Abstract

Aims: Despite improvements in cardiac haemodynamics and symptoms, long-term mortality remains increased in some patients after aortic valve replacement (AVR). Limited data exist on the prognostic role of left ventricular (LV) chamber stiffening in these patients.

Methods and results: We performed a retrospective analysis in 1893 patients with severe aortic stenosis (AS) referred for AVR. LV end-diastolic pressure-volume relations (EDPVR, P = αV^β) were reconstructed from echocardiographic measurements of end-diastolic volumes and estimates of end-diastolic pressure (EDP). The impact of EDPVR-derived LV chamber stiffness (CS30, at 30 mmHg EDP) on all-cause mortality after AVR was evaluated. Mean age was 76 ± 10 years, 39% were females, and ejection fraction (EF) was 61 ± 12%. The mean LV chamber stiffness (CS30) was 2.2 ± 1.3 mmHg/mL. A total of 877 (46%) patients had high LV stiffness (CS30 >2 mmHg/mL). In these patients, the EDPVR curves were steeper and shifted leftwards, indicating higher stiffness at all pressure levels. These patients were slightly older, more often female, and had more prevalent comorbidities compared to patients with low stiffness. At follow-up [median 4.2 (interquartile range 2.8-6.3) years; 675 deaths], a higher CS30 was associated with lower survival (hazard ratio: 2.7 for severe vs. mild LV stiffening; P < 0.0001), both in patients with normal or reduced EF. At multivariate analysis, CS30 remained an independent predictor, even after adjusting for age, sex, comorbidities, EF, LV remodelling, and diastolic dysfunction.

Conclusion: Higher preoperative LV chamber stiffening in patients with severe AS is associated with poorer outcome despite successful AVR.

Keywords: aortic stenosis; diastole; diastolic function; myocardial stiffness; ventricular stiffness.