Impact of Prosthesis-Patient Mismatch after Mitral Valve Replacement

The study aim was to determine the impact of prosthesis-patient mismatch (PPM) on early and late clinical outcomes, left atrial and ventricular remodeling, late tricuspid valve regurgitation and pulmonary hypertension (PH) in patients after mitral valve replacement (MVR).

A total of 46 patients (mean age 66 ± 9.3 years) with mitral valve diseases and undergoing isolated MVR was enrolled in the study. The mitral valve effective orifice area (EOA) was determined using the continuity equation and indexed for the patient's body surface area (EOAi). PPM was defined as EOAi ≤1.2 cm2/m2. PH was defined as a systolic pulmonary artery pressure (sPAP) >40 mmHg. Both, clinical and echocardiographic follow up were performed.

PPM was identified in 25% of patients, but no significant differences were observed in baseline and operative characteristics when comparing patients with and without PPM. The NYHA class was improved in most cases after surgery. Indeed, significant decreases in mean transvalvular gradient (from 8.6 ± 2.8 mmHg to 5 ± 1.3 mmHg, p = 0.001), left atrial dimension (LAD) (from 31.9 ±9.8 mm to 29.5 ± 7 mm, p = 0.011), left ventricular end-systolic diameter (from 42.6 ± 18.1 mm to 35.5 ± 6.6 mm, p = 0.044) and left ventricular end-diastolic diameter (from 55.8 ± 19.2 mm to 48.7 ± 6.1 mm, p = 0.024) were observed over time when comparing preoperative and postoperative echocardiographic data. In addition, at follow up (mean 6.9 ± 1.8 years) there were significant decreases in LAD (from 31.9 ± 9.8 mm to 28 ± 11.1 mm, p = 0.001), left ventricular enddiastolic volume (from 106.9 ± 32.9 ml to 92.3 ± 21.9 ml, p = 0.024), tricuspid regurgitation (TR) (from 87% to 27%, p = 0.002) and PH (from 78.3% to 58.7%, p = 0.043) in all patients. No significant differences were observed in hemodynamic, clinical outcome and atrial natriuretic peptide levels of patients with and without PPM.

Mitral PPM does not appear to have any negative effect on ventricular and atrial remodeling, TR and PH during the early and late postoperative periods.