Effect of aortic regurgitation following transcatheter aortic valve implantation on outcomes

The Role of Cardiac Magnetic Resonance in Aortic Stenosis and Regurgitation

Cardiac magnetic resonance (CMR) imaging is a well-set diagnostic technique for assessment of valvular heart diseases and is gaining ground in current clinical practice. It provides high-quality images without the administration of ionizing radiation and occasionally without the need of contrast agents. It offers the unique possibility of a comprehensive stand-alone assessment of the heart including biventricular function, left ventricle remodeling, myocardial fibrosis, and associated valvulopathies. CMR is the recognized reference for the quantification of ventricular volumes, mass, and function. A particular strength is the ability to quantify flow, especially with new techniques which allow accurate measurement of stenosis and regurgitation. Furthermore, tissue mapping enables the visualization and quantification of structural changes in the myocardium. In this way, CMR has the potential to yield important prognostic information predicting those patients who will progress to surgery and impact outcomes. In this review, the fundamentals of CMR in assessment of aortic valve diseases (AVD) are described, together with its strengths and weaknesses. This state-of-the-art review provides an updated overview of CMR potentials in all AVD issues, including valve anatomy, flow quantification, ventricular volumes and function, and tissue characterization.

Predictors and impact of low diastolic blood pressure and widened pulse pressure following transcatheter aortic valve replacement

BACKGROUND

The association between post-operative diastolic blood pressure (DBP) and pulse pressure (PP) with outcomes following transcatheter aortic valve replacement (TAVR) remains unclear. We sought to assess the prevalence, predictors, and impact of post-operative DBP and PP on presence of post-procedural aortic insufficiency (AI) and mortality in adults undergoing TAVR.

METHODS

The study population included 194 patients who underwent TAVR from 2016 to 2017 at an academic tertiary medical center, of which 176 had invasive arterial pressures available postoperatively. Low DBP and widened PP were defined as ≤40 mmHg and ≥80 mmHg respectively on invasive arterial line on post-operative day 1. Clinical outcomes of interest included post-procedural AI and 1-year all-cause mortality.

RESULTS

Post-operative low DBP and widened PP were noted in 32.4% and 58.5% of the study population. No significant association between post-operative AI and low DBP (p = 0.82) or widened PP (p = 0.32) was noted. There was a trend toward higher rates of mortality in patients with low DBP (19.3% vs 9.2%, p = 0.06) but no difference in mortality in patients with widened PP (10.7% vs 15.1%, p = 0.39) or those with ≥1+ post-procedural AI (16.7% vs 10.7%, p = 0.32). In multivariable analysis, low DBP was associated with a trend toward higher rates of 1-year mortality [odds ratio (OR) 2.43, 95% confidence interval (CI) 0.97-6.11, p = 0.06]. When excluding patients with a post-operative invasive systolic blood pressure < 80 mmHg, low DBP was associated with significantly higher risk-adjusted mortality at 1 year [OR 2.75, 95% CI (1.07-7.07), p = 0.04].

CONCLUSIONS

In this contemporary study of adults undergoing TAVR, low DBP and widened PP were widely prevalent post TAVR. Low DBP was associated with a trend toward higher rates of 1-year mortality but not with post-procedural AI.

Five-year echocardiographic follow-up after TAVI: structural and functional changes of a balloon-expandable prosthetic aortic valve

Aims

Scarce data are available on the long-term structural and functional changes of prosthetic valves after transcatheter aortic valve implantation (TAVI). The objective was to evaluate with echocardiography the long-term structural and functional changes of prosthetic valves after TAVI.

Methods and results

Structural valve deterioration (SVD) was defined as leaflet thickening ≥3mm, presence of calcification and abnormal leaflet motion. Five-year echocardiographic follow-up was available in 96 out of 318 patients who underwent TAVI with a balloon-expandable device between April 2008 and December 2011. At 1-year follow-up, no patient showed SVD. At 5-year follow-up, SVD were observed in 29 (30%) patients who showed also a significant reduction of aortic valve area (AVA) together with an increase of mean and peak aortic pressure gradients at the latest echocardiography evaluation. Moreover, rate of central aortic valve regurgitation ≥2 was higher in SVD patients as compared to those without SVD, while there was no difference in terms of paravalvular regurgitation. Despite SVD, one patient only reached the criteria for severe stenosis and no reintervention was needed at 5-year follow-up. Variables independently associated with SVD were female sex, small body surface area, use of a 23 mm valve, and small AVA at pre-discharge echocardiogram.

Conclusion

At 5-year follow-up, 30% of patients who underwent TAVI with a balloon-expandable valve showed initial SVD. However, SVD was not associated with severe stenosis in most of the patients and had no significant impact on and clinical outcome.

Mitral Regurgitation After Transcatheter Aortic Valve Replacement: Prognosis, Imaging Predictors, and Potential Management

OBJECTIVES

This study sought to analyze the clinical impact of the degree and improvement of mitral regurgitation in TAVR recipients, validate the main imaging determinants of this improvement, and assess the potential candidates for double valve repair with percutaneous techniques.

BACKGROUND

Many patients with severe aortic stenosis present with concomitant mitral regurgitation (MR). Cardiac imaging plays a key role in identifying prognostic factors of MR persistence after transcatheter aortic valve replacement (TAVR) and for planning its treatment.

METHODS

A total of 1,110 patients with severe aortic stenosis from 6 centers who underwent TAVR were included. In-hospital to 6-month follow-up clinical outcomes according to the degree of baseline MR were evaluated. Off-line analysis of echocardiographic and multidetector computed tomography images was performed to determine predictors of improvement, clinical outcomes, and potential percutaneous alternatives to treat persistent MR.

RESULTS

Compared with patients without significant pre-TAVR MR, 177 patients (16%) presented with significant pre-TAVR MR, experiencing a 3-fold increase in 6-month mortality (35.0% vs. 10.2%; p < 0.001). After TAVR, the degree of MR improved in 60% of them. A mitral annular diameter of >35.5 mm (odds ratio: 9.0; 95% confidence interval: 3.2 to 25.3; p < 0.001) and calcification of the mitral apparatus by multidetector computed tomography (odds ratio: 11.2; 95% confidence interval: 4.03 to 31.3; p < 0.001) were independent predictors of persistent MR. At least 14 patients (1.3% of the entire cohort, 13.1% of patients with persistent MR) met criteria for percutaneous mitral repair with either MitraClip (9.3%) or a balloon-expandable valve (3.8%).

CONCLUSIONS

Significant MR is not uncommon in TAVR recipients and associates with greater mortality. In more than one-half of patients, the degree of MR improves after TAVR, which can be predicted by characterizing the mitral apparatus with multidetector computed tomography. According to standardized imaging criteria, at least 1 in 10 patients whose MR persists after TAVR could benefit from percutaneous mitral procedures, and even more could be treated with MitraClip after dedicated pre-imaging evaluation.

Update on the significance of postprocedural aortic regurgitation after transcatheter aortic valve replacement on postprocedural prognosis

Transcatheter aortic valve replacement (TAVR) is an established therapy for patients with aortic stenosis and a high surgical risk. Recent data on intermediate-risk patients will probably enlarge the indication for TAVR. In the beginning of the TAVR era, relevant (>mild) aortic regurgitation (AR) was a common finding after TAVR; it was associated with worse outcome compared with patients without significant AR. To date, several improvements in imaging, grading of severity and treatment have been done and will be discussed in this article. AR after TAVR still is a strong and independent predictor of 1-year mortality and every effort should be made to prohibit its development.

Does pre-existing aortic regurgitation protect from death in patients who develop paravalvular leak after TAVI?

OBJECTIVE

The aim of this study was to investigate interactions among pre-procedural aortic regurgitation (AR), post-procedural paravalvular leak (PVL) and long-term clinical outcomes.

METHODS AND RESULTS

We analyzed data prospectively collected in the Italian Transcatheter balloon-Expandable Registry (ITER) on aortic stenosis (AS) patients. The degree of pre-procedural AR and post-procedural PVL was stratified as: absent/trivial, mild, and moderate/severe. VARC definitions were applied to outcomes. Of 1708 patients, preoperatively, AR was absent/trivial in 40% of the patients, mild in 42%, and moderate in 18%. Postoperatively, PVL was moderate-severe in 5%, mild in 32% of patients, and absent/trivial in 63%. Clinical follow-up, median 821days (IQR 585.75), was performed in 99.7% of patients. PVL, but not preoperative AR, was a major predictor of adverse outcome (HR 1.33, CI 95% 0.9-2.05, p=0.012 for mild PVL, HR 1.36, CI 95% 0.9-2.05, p<0.001 for PVL≥moderate and OR 1.04, p=0.97 respectively). Patients with moderate-severe PVL and preoperative left ventricle (LV) dilatation (LVEDVi>75ml/m²) showed better survival than those without dilatation (HR 8.63, p=0.001).

CONCLUSIONS

In patients with severe AS treated with balloon-expandable TAVI, the presence of PVL, but not pre-procedural AR, was a major predictor of adverse outcome. Preoperative LV dilatation seemed to offer some clinical advantages.

Correlation of CoreValve implantation 'true cover index' with short and mid-term aortic regurgitation: A novel index

BACKGROUND

'Cover index' has been proposed to appraise the congruence between the aortic annulus and the device, with the assumption of not taking into account the actual device implantation depth. The aim of this study was to investigate whether the annulus-prosthesis mismatch, as expressed with the new proposed 'true cover index' according to actual implantation depth, can predict aortic regurgitation (AR) after transcatheter aortic valve implantation (TAVI).

METHODS

Patients who had undergone TAVI with the self-expandable CoreValve device, were retrospectively studied. All available prosthesis sizes were ex-vivo scanned and the precise diameter at 0.3mm intervals along each device was measured. The 'true cover index' was evaluated, as a ratio of the following: 100×([prosthesis actual diameter at implantation depth-annulus diameter]/prosthesis actual diameter at implantation depth). AR was echocardiographically evaluated at discharge and 30days and classified as prominent if moderate, or trivial if none or mild.

RESULTS

Overall, 120 patients who had undergone TAVI, were considered eligible for the study. 'True cover index' was statistically significantly lower among patients with prominent AR in comparison with trivial AR at discharge (5.7±4.8mm vs 9±5.1, p=0.025), as well as at one month post-TAVI (5.4±5.1mm vs 9.0±5.1, p=0.023), indicating increased AR for smaller index. After adjustment for severe annulus calcification, impaired baseline LVEF and previous valvuloplasty, it remained an independent predictor of one month prominent AR (OR: 0.854, CI: 0.730-0.999; p=0.048). 'True cover index' of <4.3 was shown to predict one-month prominent AR with sensitivity =75% and specificity =82.5%.

CONCLUSIONS

'True cover index' is strongly and independently correlated with the short and mid-term AR after CoreValve implantation.