Prognostic Impact of Left Atrial Function Following Transcatheter Mitral Valve Repair

Left atrial phasic function: physiology, clinical assessment and prognostic value

Left atrial (LA) phasic function provides significant insights into the pathophysiology of cardiovascular disease. LA function is described in three phases: reservoir (atrial filling, during systole), conduit (passive emptying, during early diastole) and contractile (active emptying, during late diastole). LA phasic function can be evaluated by different imaging modalities, and a variety of techniques including volumetric analysis, deformation (strain) and Doppler methods. LA phasic function (particularly LA reservoir strain) is more sensitive and provides earlier detection of LA dysfunction than alterations in LA volume. LA function parameters have also demonstrated significant diagnostic and prognostic value, particularly in heart failure, atrial fibrillation and stroke. However, there remain barriers to implementation of phasic function parameters in clinical practice and guidelines. This review outlines the physiology of LA phasic function, methods of assessment, and its diagnostic and prognostic utility in varying pathologies.

Differential prognostic accuracy of right ventricular dysfunction, the Seattle heart failure model and the MAGGIC score in patients with severe mitral regurgitation undergoing the MitraClip® procedure

Background

MitraClip ® (MC) is an established procedure for severe mitral regurgitation (MR) in patients deemed unsuitable for surgery.

Right ventricular dysfunction (RVD) is associated with a higher mortality risk. The prognostic accuracy of heart failure risk scores like the Seattle heart failure model (SHFM) and Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC) score in pts undergoing MC with or without RVD has not been investigated so far.

Methods

SHFM and MAGGIC score were calculated retrospectively. RVD was determined as tricuspid annular plane systolic excursion (TAPSE) ≤15 mm. Area under receiver operating curves (AUROC) of SHFM and MAGGIC were performed for one-year all-cause mortality after MC.

Results

N = 103 pts with MR III° (73 ± 11 years, LVEF 37 ± 17%) underwent MC with a reduction of at least I° MR. One-year mortality was 28.2%.

In Kaplan-Meier analysis, one- year mortality was significantly higher in RVD-pts (34.8% vs 2.8%, p = 0.009).

Area under the Receiver Operating Characteristic (AUROC) for SHFM and MAGGIC were comparable for both scores (SHFM: 0.704, MAGGIC: 0.692). In pts without RVD, SHFM displayed a higher AUROC and therefore better diagnostic accuracy (SHFM: 0.776; MAGGIC: 0.551, p < 0.05). In pts with RVD, MAGGIC and SHFM displayed comparable AUROCs.

Conclusion

RVD is an important prognostic marker in pts undergoing MC. SHFM and MAGGIC displayed adequate over-all prognostic power in these pts. Accuracy differed in pts with and without RVD, indicating higher predictive power of the SHFM score in pts without RVD.

Left atrial global function in chronic heart failure patients with functional mitral regurgitation after MitraClip

BACKGROUND

Left atrial (LA) volumes and function are believed to improve following interventional reduction of mitral regurgitation (MR) with MitraClip. However, exact LA alterations after MitraClip in patients with functional MR and functional mitral regurgitation (FMR) are unknown.

OBJECTIVES

We aimed to evaluate the effect of MitraClip on LA volumes and global function in patients with FMR and its importance for patients' prognosis.

METHODS

All patients underwent three-dimensionally transthoracic echocardiography with an offline evaluation of LA geometry and strain analysis at baseline and follow-up (FU). FU examinations were planned for 6 and 12 months after MitraClip.

RESULTS

We prospectively included 50 consecutive surgical high-risk (logistic EuroSCORE: 17.2 ± 13.9%) patients (77 ± 9 years, 22% female) with symptomatic moderate-to-severe to severe functional MR without atrial fibrillation. Echocardiographic evaluation showed that the E/E' ratio was significantly higher at FU (15.6 ± 7.3, 24.1 ± 13.2, p = .05) without relevant changes in systolic left ventricle (LV) function (p = .5). LA volumes (end-diastolic volume [LA-EDV] and end-systolic volume [LA-ESV]) (LA-EDV: 83.1 ± 39.5 ml, 115.1 ± 55.3 ml, p = .012; LA-ESV: 58.4 ± 33.4 ml, 80.1 ± 43.9 ml, p = .031), muscular mass (105.1 ± 49.3 g, 145.4 ± 70.6 g, p = .013), as well as LA stroke volume (24.6 ± 12.5 ml, 34.9 ± 19.1 ml, p = .016) significantly increased after the procedure. LA ejection fraction (LA-EF: 31.7 ± 12.8%, 31.1 ± 12.3%, p = .8) and atrial global strain (aGS: -10.8 ± 5.4%, -9.7 ± 4.45%, p = .4) showed no significant changes at FU. Despite no relevant changes during FU, the baseline aGS was found to be the strongest predictor for mortality and adverse interventional outcome.

CONCLUSION

MitraClip increases atrial stroke volume, atrial volumes, and muscular mass in patients with FMR. We found that the baseline aGS the strongest predictor for mortality, rehospitalization, and higher residual MR at FU.

Prognostic Impact of Left Atrial Function Following Transcatheter Mitral Valve Repair

Background

Left atrial (LA) function predicts clinical outcome in a variety of cardiovascular diseases. However, limited data are available in the setting of mitral regurgitation. The aim of the present study was to assess potential changes in LA ejection fraction (LAEF) and its prognostic value in patients following transcatheter mitral valve repair using the MitraClip.

Methods and Results

A total of 88 consecutive patients undergoing MitraClip implantation with complete echocardiography at baseline and follow‐up between 3 and 6 months postprocedure were enrolled. LAEF improved in 58% of the population. Change in LAEF was associated with residual mitral regurgitation, residual transmitral gradient and left ventricular ejection fraction changes. Compared with their counterparts, patients with residual mitral regurgitation ≥grade 2 (change in LAEF, −6% [Interquartile [IQR], −9–1%] versus 4% [IQR, −5–15%]; P=0.05) and with residual transmitral gradient ≥5 mm Hg (change in LAEF, −2% [IQR, −9–9%] versus 5% [IQR, −4–16%]; P=0.03) showed a decline in LAEF, respectively. Furthermore, LAEF significantly correlated with changes in left ventricular ejection fraction (r=0.40; P=0.001). With regards to clinical outcome, heart failure symptoms as assessed by New York Heart Association class were more severe in patients with worsened LAEF at follow‐up. Finally, LAEF change was identified as an independent predictor of all‐cause mortality (hazard ratio, 0.94; 95% CI, 0.90–0.98 [P=0.008]).

Conclusions

The present analysis showed that changes in LA function in patients undergoing MitraClip implantation are associated with important measures including residual mitral regurgitation, elevated transmitral gradient, and left ventricular function. Importantly, LA function alterations represent a strong predictor for all‐cause mortality.