ABSTRACT
Background: Transcatheter therapy has become an alternative for functional mitral regurgitation (FMR) in patients at high surgical risk. However, the intervention of FMR in cardiac amyloidosis (CA) with transcatheter edge-to-edge repair (TEER) is controversial due to the potential risk of left atrial pressure (LAP) elevation. Case summary: An 83-year-old woman with repeated heart failure (HF) and severe mitral regurgitation (MR) was referred to our centre for TEER. Pre-procedural transthoracic echocardiography (TTE) and transoesophageal echocardiography (TOE) confirmed the degree of MR and a functional aetiology. A peculiar LAP increase in this patient occurred immediately after successful TEER clip implantation and her n-terminal prohormone of brain natriuretic peptide significantly increased post-operatively. The diagnosis of CA was suspected and was subsequently established through endomyocardial biopsy. Aggressive anti-HF therapy was initiated and the patient was discharged after her HF symptoms were relieved. At 6-month follow-up, the patient was still alive and no episode of acute HF was experienced. Discussion: Severe functional MR in CA treated with TEER has the potential risk of increasing LAP. During the short-term follow-up, TEER appears beneficial for left heart function (reduction of MR) but harmful for right heart function (increase of LAP). CA patients with severe FMR should be carefully evaluated about the benefits and potential harm of TEER intervention.
ABSTRACT
Objective:To investigate the effect of instantaneous flow rate on the consistency of diagnostic accuracy of severe degenerative mitral regurgitation (DMR) using proximal isovelocity surface area (PISA).Methods:From June 2019 to June 2021, 75 patients with DMR who underwent echocardiography in Department of Echocardiography of Zhongshan Hospital, Fudan University were prospectively enrolled. The instantaneous flow rate of DMR during the systolic phase was calculated using M-mode PISA(PISA M-mode), and a time-integrated curve was plotted. Regurgitant volume (RVol) and effective regurgitant orifice area (EROA) were calculated by traditional PISA (PISA max), pair PISA (PISA pair), and PISA M-mode, respectively. RVol acquired from cardiac magnetic resonance (CMR) volumetric method in 22 patients of the enrolled patients. The correlation and consistency of RVol acquired between the three PISA methods and CMR were compared. Agreement of diagnostic accuracy of severe mitral regurgitation (sMR) acquired between the three PISA methods and multi-parameter algorithm by American Society of Echocardiography (ASE) was analyzed using Cohen′s Kappa analysis. Results:The curve of instantaneous flow rate of DMR showed unimodal pattern with the peak at mid-late systolic phase. The correlation of RVol acquired between PISA methods and CMR was moderate for PISA max and PISA pair ( r=0.77, 0.80, both P<0.001), whereas PISA M-mode presented strong correlation with CMR ( r=0.87, P<0.001). RVol acquired from PISA max was larger than that of CMR[(69.1±37.1) ml vs (49.0±29.0)ml, P=0.002]. Both PISA max and PISA pair were shown moderate agreement of diagnostic accuracy of sMR with ASE multi-parameters algorithm (RVol: κ=0.496, 0.525, both P<0.001; EROA: κ=0.570, 0.578, both P<0.001), while PISA M-mode presented strong agreement (RVol: κ=0.867 and EROA: κ=0.802, both P<0.001). Conclusions:Based on the unimodal pattern of instantaneous flow rate in patients with DMR, PISA max may significantly overestimate RVol, exposing a significant proportion of patients with DMR to unnecessary MR surgery. PISA M-mode presents better correlation and consistency with CMR on the quantification of RVol compared with PISA max and PISA pair, and may improve the diagnostic accuracy of quantification of sMR using PISA.
