Impact of mild patient prosthesis mismatch on quality of life in patients with preserved ejection fraction after isolated aortic valve replacement for aortic stenosis

Abstract

Aim

To analyze whether PPM affects QOL and functional status in patients after isolated AVR for aortic stenosis (AS) with preserved left ventricular ejection fraction (LVEF).

Methods

Consecutive patients who underwent AVR in University Hospital Center Zagreb for isolated severe symptomatic AS and preserved EF were enrolled. Echo data was obtained from complete transthoracic examinations prior and after surgery by offline analysis. Patients were divided into two groups according to the presence of PPM (effective orifice area (EOA) / body surface area (BSA) < 0,85 cm²/m²). QOL was assessed by telephone interview using Short Form 36-Item Health Survey (SF-36) along with functional NYHA status estimation.

Results

A total of 45 pts were included (23 female), and divided in PPM (n = 26), and non-PPM group (n = 19). Both groups were similar in pts age, LVEF, AVA/BSA prior surgery. After surgery, 57% of pts had PPM categorized as mild PPM. During follow-up of 2,5 years, 3 pts had died and 10 were lost from following. There was no difference in NYHA status after surgery between groups (p = 0,758). SF36 results showed no difference between groups. However, there was a significant improvement in Physical functioning (47,50% vs 75,47%,p = 0,000) and Role limitation due to physical health (41,41% vs 81,25%, p = 0,007) scores in the whole study population after AVR. Males had significantly better Energy/fatigue (p = 0,034), Social functioning (p = 0,004) and Pain (p = 0,017) scores.

Conclusions

Mild to moderate PPM showed no clinical relevance. All patients revealed improvement in QOL after AVR, while male sex was related to better functioning scores irrespectively of PPM.

Introduction

Since it was first described by Rahimtoola in 1978 [1], patient prosthesis mismatch (PPM) has caused a lot of controversies. It means that the effective orifice area (EOA) of the implanted valve is too small for the patient's body surface area (BSA). PPM is more common in patients with large BSA, but it also depends on the left ventricular outflow tract (LVOT) diameter [2], [3], [4]. In patients with aortic stenosis, due to left ventricular hypertrophy and excessive calcifications, LVOT diameter gradually gets smaller and precludes implantation of the prosthetic valve of appropriate size [4].

PPM is generally a relatively common finding, found in up to 70% AVR procedures [2], [5], [6], [7], [8]. If the EOA/BSA ratio is < 0,85 cm²/m², PPM is defined as mild or moderate, and as severe if the EOA/BSA ratio is < 0,65 cm²/m² [2]. Patient outcomes mainly depend on the severity of PPM. Severe PPM has been shown to have worse long term survival, lower cardiac-related-death survival and lower left ventricular (LV) mass reduction [9].

However, the impact of patient prosthesis mismatch on the outcomes remains unresolved. In some studies, PPM did impact long term survival and cardiac related deaths [9], [10], [11] whereas in others there was no significant difference compared to no PPM patients [8], [11], [12]. Studies are more uniform regarding functional capacity, with no difference compared to no PPM patients, especially in the elderly [5], [7], [12], [13], [14], [15], [16].

In younger, middle-aged patients, the impact of PPM on functional capacity and QOL remains unclear. Higher gradients and less positive remodeling of the left ventricle may have some impact on their functional capacity and the risk for reoperation [8]. The aim of the study was to investigate the impact of PPM on survival, quality of life and functional status in general population with preserved ejection fraction after isolated AVR.