Left ventricular functional recovery and remodeling in low-flow low-gradient severe aortic stenosis after transcatheter aortic valve implantation

Patients with paradoxical low-flow, low-gradient aortic stenosis gain the least benefit from TAVI among all hemodynamic subtypes

BACKGROUND

Substantial controversy exists regarding the clinical benefit of patients with severe paradoxical low-flow, low-gradient aortic stenosis (PLF-LG AS) from TAVI. Therefore, we compared post-TAVI benefit by long-term mortality (all-cause, CV and SCD), clinical improvement of heart failure symptoms, and cardiac reverse remodelling in guideline-defined AS subtypes.

METHODS

We prospectively included 250 consecutive TAVI patients. TTE, 6mwt, MLHFQ, NYHA status and NT-proBNP were recorded at baseline and 6 months. Long-term mortality and causes of death were assessed.

RESULTS

107 individuals suffered from normal EF, high gradient AS (NEF-HG AS), 36 from low EF, high gradient AS (LEF-HG), 52 from "classic" low-flow, low-gradient AS (LEF-LG AS), and 38 from paradoxical low-flow, low-gradient AS (PLF-LG AS). TAVI lead to a significant decrease in MLHFQ score and NT-proBNP levels in all subtypes except for PLF-LG. Regarding reverse remodelling, a significant increase in EF and decrease in LVEDV was present only in subtypes with reduced baseline EF, whereas a significant decrease in LVMI and LAVI could be observed in all subtypes except for PLF-LG. During a follow-up of 3-5 years, PLF-LG patients exhibited the poorest survival among all subtypes (HR 4.2, P = 0.0002 for CV mortality; HR 7.3, P = 0.004 for SCD, in comparison with NEF-HG). Importantly, PLF-LG was independently predictive for CV mortality (HR 2.9 [1.3-6.9], P = 0.009).

CONCLUSIONS

PLF-LG patients exhibit the highest mortality (particularly CV and SCD), the poorest symptomatic benefit and the least reverse cardiac remodelling after TAVI among all subtypes. Thus, this cohort seems to gain the least benefit.

Long-Term Outcomes of Aortic Stenosis Patients with Different Flow/Gradient Patterns Undergoing Transcatheter Aortic Valve Implantation

Background: Few data exist on the comparative long-term outcomes of severe aortic stenosis (AS) patients with different flow-gradient patterns undergoing transcatheter aortic valve implantation (TAVI). This study sought to evaluate the impact of the pre-TAVI flow-gradient pattern on long-term clinical outcomes after TAVI and assess changes in the left ventricular ejection fraction (LVEF) of different subtypes of AS patients following TAVI. Methods: Consecutive patients with severe AS undergoing TAVI in our institution were screened and prospectively enrolled. Patients were divided into four subgroups according to pre-TAVI flow/gradient pattern: (i) low flow-low gradient (LF-LG): stroke volume indexed (SVi) ≤ 35 mL/m2 and mean gradient (MG) < 40 mmHg); (ii) normal flow-low gradient (NF-LG): SVi > 35 mL/m2 and MG < 40 mmHg; (iii) low flow-high gradient (LF-HG): Svi 35 mL/m2 and MG ≥ 40 mmHg and (iv) normal flow-high gradient (NF-HG): SVi > 35 mL/m2 and MG ≥ 40 mmHg. Transthoracic echocardiography was repeated at 1-year follow-up. Clinical follow-up was obtained at 12 months, and yearly thereafter until 5-year follow-up was complete for all patients. Results: A total of 272 patients with complete echocardiographic and clinical follow-up were included in our analysis. Their mean age was 80 ± 7 years and the majority of patients (N = 138, 50.8%) were women. 62 patients (22.8% of the study population) were distributed in the LF-LG group, 98 patients (36%) were LF-HG patients, 95 patients (34.9%) were NF-HG, and 17 patients (6.3%) were NF-LG. There was a greater prevalence of comorbidities among LF-LG AS patients. One-year all-cause mortality differed significantly between the four subgroups of AS patients (log-rank p: 0.022) and was more prevalent among LF-LG patients (25.8%) compared to LF-HG (11.3%), NF-HG (6.3%) and NF-LG patients (18.8%). At 5-year follow-up, global mortality remained persistently higher among LF-LG patients (64.5%) compared to LF-HG (47.9%), NF-HG (42.9%), and NF-LG patients (58.8%) (log-rank p: 0.029). At multivariable Cox hazard regression analysis, baseline SVi (HR: 0.951, 95% C.I.; 0.918-0.984), the presence of at least moderate tricuspid regurgitation at baseline (HR: 3.091, 95% C.I: 1.645-5.809) and at least moderate paravalvular leak (PVL) post-TAVI (HR: 1.456, 95% C.I.: 1.106-1.792) were significant independent predictors of late global mortality. LF-LG patients and LF-HG patients exhibited a significant increase in LVEF at 1-year follow-up. A lower LVEF (p < 0.001) and a lower Svi (p < 0.001) at baseline were associated with LVEF improvement at 1-year. Conclusions: Patients with LF-LG AS have acceptable 1-year outcomes with significant improvement in LVEF at 1-year follow-up, but exhibit exceedingly high 5-year mortality following TAVI. The presence of low transvalvular flow and at least moderate tricuspid regurgitation at baseline and significant paravalvular leak post-TAVI were associated with poorer long-term outcomes in the entire cohort of AS patients. The presence of a low LVEF or a low SVi predicts LVEF improvement at 1-year.

Multimodality imaging for the global evaluation of aortic stenosis: The valve, the ventricle, the afterload

Aortic stenosis (AS) is the most common valvular heart disease growing in parallel to the increment of life expectancy. Besides the valve, the degenerative process affects the aorta, impairing its elastic properties and leading to increased systemic resistance. The composite of valvular and systemic afterload mediates ventricular damage. The first step of a thorough evaluation of AS should include a detailed assessment of valvular anatomy and hemodynamics. Subsequently, the ventricle, and the global afterload should be assessed to define disease stage and prognosis. Multimodality imaging is of paramount importance for the comprehensive evaluation of these three elements. Echocardiography is the cornerstone modality whereas Multi-Detector Computed Tomography and Cardiac Magnetic Resonance provide useful complementary information. This review comprehensively examines the merits of these imaging modalities in AS for the evaluation of the valve, the ventricle, and the afterload and ultimately endeavors to integrate them in a holistic assessment of AS.

The prognostic impact of diastolic dysfunction after transcatheter aortic valve replacement: A systematic review and meta-analysis

BACKGROUND

Diastolic dysfunction (DD) is a long-established marker of disease progression in patients with aortic valve stenosis (AS), indicating valvular myocardial damage. Recently, substantial observational data have emerged demonstrating that worse pre-operative DD assessed using echocardiography is associated with adverse long-term clinical outcomes after transcatheter aortic valve replacement (TAVR).

AIM

To systematically appraise and quantitatively synthesize current evidence on the prognostic impact of echocardiographic severe DD derived by echocardiography before TAVR.

METHODS

A systemic literature review was undertaken in electronic databases to identify studies reporting the predictive value of severe DD in AS subjects undergoing TAVR. A random-effects meta-analysis was conducted to quantify the adjusted and unadjusted hazard ratios (HRs) for all-cause mortality and major adverse cardiovascular events (MACEs) for the presence of severe DD.

RESULTS

Ten studies were deemed eligible for inclusion. Of those, 9 provided appropriate quantitative data for the meta-analysis, encompassing a total of 4,619 patients. The presence of severe DD was associated with increased risk for all-cause mortality (pooled unadjusted HR=2.56 [1.46-4.48]; p<0.01; I2=76 %) and MACEs (pooled unadjusted HR=1.82 [1.29-2.58]; p<0.01; I2=86 %). When adjusted for clinically-relevant parameters, the presence of severe DD retained independent association with all-cause mortality (pooled adjusted HR=2.35 [1.26-4.37]; p<0.01; I2=79 %) and MACEs (pooled adjusted HR= 2.52 [1.72-3.65]; p<0.01; I2=0 %). In subgroup analysis there was no difference on post-TAVR risk between the use of different diastolic function grading scores.

CONCLUSION

Presence of severe DD assessed by echocardiography pre-TAVR is a major determinant of long-term adverse outcomes after the procedure.

Strain Assessment in Aortic Stenosis: Pathophysiology and Clinical Utility

Contemporary echocardiographic criteria for grading aortic stenosis severity have remained relatively unchanged, despite significant advances in noninvasive imaging techniques over the last 2 decades. More recently, attention has shifted to the ventricular response to aortic stenosis and how this might be quantified. Global longitudinal strain, semiautomatically calculated from standard two-dimensional echocardiographic images, has been the focus of extensive research. Global longitudinal strain is a sensitive marker of subtle hypertrophy-related impairment in left ventricular function and has shown promise as a relatively robust prognostic marker, both independently and when added to severity classification systems. Herein we review the pathophysiological basis underpinning the potential utility of global longitudinal strain in the assessment of aortic stenosis, as well as its potential role in quantifying myocardial recovery and prognostic discrimination following aortic valve replacement.

Quantification of cardiac pumping mechanics in TAVI patients: A pilot study utilizing minimally invasive method for pressure-volume analysis

The ventriculo-arterial coupling (VAC) and left ventricle (LV) mechanics are crucial and play an important role in the pathophysiology of aortic stenosis (AS). The pressure-volume (PV) analysis is a powerful tool to study VAC and LV mechanics. We proposed a novel minimally-invasive method for PV analysis in patients with severe AS receiving transcatheter aortic valve implantation (TAVI). Patients with severe AS were prospectively enrolled in a single center. LV pressure and cardiac output were recorded before and after TAVI. We constructed the PV loop for analysis by analyzing LV pressure and the assumed flow. 26 patients were included for final analysis. The effective arterial elastance (Ea) decreased after TAVI (3.7 ± 1.3 vs. 2.9 ± 1.1 mmHg/mL, p < 0.0001). The LV end-systolic elastance (Ees) did not change immediately after TAVI (2.4 ± 1.3 vs. 2.6 ± 1.1 mmHg/mL, p = 0.3670). The Ea/Ees improved after TAVI (1.8 ± 0.8 vs. 1.2 ± 0.4, p < 0.0001), demonstrating an immediate improvement of VAC. The stroke work (SW) did not change (7669.6 ± 1913.8 vs. 7626.2 ± 2546.9, p = 0.9330), but the pressure-volume area (PVA) decreased (14469.0 ± 4974.1 vs. 12177.4 ± 4499.9, p = 0.0374) after TAVI. The SW/PVA increased after TAVI (0.55 ± 0.12 vs. 0.63 ± 0.08, p < 0.0001) representing an improvement of LV efficiency. We proposed a novel minimally invasive method for PV analysis in patients with severe AS receiving TAVI. The VAC and LV efficiency improved immediately after TAVI.

Shifting from Left Ventricular Ejection Fraction to Strain Imaging in Aortic Stenosis

Adverse ventricular remodeling is an inflexion point of disease progression in aortic stenosis (AS) and a major determinant of prognosis. Intervention before irreversible myocardial damage is of paramount importance to sustain favorable post-operative outcomes. Current guidelines recommend a left ventricular ejection fraction (LVEF)-based strategy to determine the threshold for intervention in AS. However, LVEF has several pitfalls: it denotes the left ventricular cavity volumetric changes and it is not suited to detecting subtle signs of myocardial damage. Strain has emerged as a contemporary imaging biomarker that describes intramyocardial contractile force, providing information on subclinical myocardial dysfunction due to fibrosis. A large body of evidence advocates its use to determine the switch from adaptive to maladaptive myocardial changes in AS, and to refine thresholds for intervention. Although mainly studied in echocardiography, studies exploring the role of strain in multi-detector row computed tomography and cardiac magnetic resonance are emerging. This review, therefore, summarizes contemporary evidence on the role of LVEF and strain imaging in AS prognosis, aiming to move from an LVEF-based to a strain-based approach for risk stratification and therapeutic decision-making in AS.

Clinical Value of Novel Echocardiographic Biomarkers Assessing Myocardial Work in Acute Heart Failure-Rationale and Design of the "Beyond Myo-HF Study"

BACKGROUND

Despite ongoing treatment advancements in chronic heart failure (HF), mortality and readmission rates remain high for patients hospitalized for decompensated acute HF. These patients represent a distinct HF group, which requires emergent echocardiographic evaluation in an attempt to provide optimal and individualized acute care. The role of serial advanced echocardiographic assessment in acute HF for risk stratification and treatment guidance has not been thoroughly explored.

METHODS

The "Beyond Myo-HF Study" is a prospective, non-interventional cohort trial designed to enroll acutely admitted patients with symptoms and/or signs of HF. The aim of this study is to investigate whether intrahospital changes of conventional and novel echocardiographic indices of myocardial function and congestion-related markers can predict early mortality, late mortality, and HF rehospitalization. As per the protocol, all patients undergo a pair of state-of-the-art echocardiographic assessments, with a rigorous protocol including speckle tracking analysis of all cardiac chambers and myocardial work analysis for the left and right ventricle, upon admission and pre-discharge. Their laboratory profile is captured at those two time-points, and their therapeutic management is recorded. Patients will be followed-up for a median period of 12 months after enrollment.

CONCLUSIONS

The "Beyond Myo-HF" study is an ongoing, prospective trial aspiring to provide deep insight into the pathophysiology of acute HF, to enlighten the reverse cardiac functional and anatomical remodeling during hospitalization, and to recognize echocardiographic patterns capable of predicting adverse outcomes during and post decompensation of acute HF.

Radiomic analysis of enhanced CMR cine images predicts left ventricular remodeling after TAVR in patients with symptomatic severe aortic stenosis

Objective

This study aimed to develop enhanced cine image-based radiomic models for non-invasive prediction of left ventricular adverse remodeling following transcatheter aortic valve replacement (TAVR) in symptomatic severe aortic stenosis.

Methods

A total of 69 patients (male:female = 37:32, median age: 66 years, range: 47-83 years) were retrospectively recruited, and severe aortic stenosis was confirmed via transthoracic echocardiography detection. The enhanced cine images and clinical variables were collected, and three types of regions of interest (ROIs) containing the left ventricular (LV) myocardium from the short-axis view at the basal, middle, and apical LV levels were manually labeled, respectively. The radiomic features were extracted and further selected by using the least absolute shrinkage and selection operator (LASSO) regression analysis. Clinical variables were also selected through univariate regression analysis. The predictive models using logistic regression classifier were developed and validated through leave-one-out cross-validation. The model performance was evaluated with respect to discrimination, calibration, and clinical usefulness.

Results

Five basal levels, seven middle levels, eight apical level radiomic features, and three clinical factors were finally selected for model development. The radiomic models using features from basal level (Rad I), middle level (Rad II), and apical level (Rad III) had achieved areas under the curve (AUCs) of 0.761, 0.909, and 0.913 in the training dataset and 0.718, 0.836, and 0.845 in the validation dataset, respectively. The performance of these radiomic models was improved after integrating clinical factors, with AUCs of the Combined I, Combined II, and Combined III models increasing to 0.906, 0.956, and 0.959 in the training dataset and 0.784, 0.873, and 0.891 in the validation dataset, respectively. All models showed good calibration, and the decision curve analysis indicated that the Combined III model had a higher net benefit than other models across the majority of threshold probabilities.

Conclusion

Radiomic models and combined models at the mid and apical slices showed outstanding and comparable predictive effectiveness of adverse remodeling for patients with symptomatic severe aortic stenosis after TAVR, and both models were significantly better than the models of basal slice. The cardiac magnetic resonance radiomic analysis might serve as an effective tool for accurately predicting left ventricular adverse remodeling following TAVR in patients with symptomatic severe aortic stenosis.

Prognostic Implications of Change in Left Ventricular Ejection Fraction After Transcatheter Aortic Valve Implantation

Reduced left ventricular (LV) systolic function is associated with worse prognosis in patients with severe aortic stenosis (AS) treated with transcatheter aortic valve implantation (TAVI). We aimed to examine the changes in left ventricular ejection fraction (LVEF) after TAVI among patients with varying baseline LVEF. Moreover, variables associated with lack of LVEF improvement were identified and the association with long-term outcomes was investigated. A total of 560 patients (age 80 ± 7 years, 53% men) with severe AS who underwent transfemoral TAVI between 2007 and 2019 were selected. LVEF was assessed from transthoracic echocardiography at baseline (before TAVI) and at 6 and 12 months after TAVI. Patients were stratified according to baseline LVEF: (1) LVEF ≥50%, (2) LVEF 40% to 49%, and (3) LVEF <40%. The clinical end point was ≥5% LVEF improvement. The primary outcome was all-cause mortality. Patients with baseline LVEF<40% showed greater increase in LVEF than those with baseline LVEF 40% to 49% and LVEF ≥50% (from 33% ± 6% to 43% ± 10%, p <0.001; from 45% ± 3% to 52% ± 8%, p <0.001; and from 58% ± 5% to 59% ± 7%, p = 0.012, respectively, p for interaction <0.001). Coronary artery disease (odds ratio [OR] 1.80 [95% confidence interval (CI) 1.06 to 3.06], p = 0.031), myocardial infarction (OR 2.07 [95% CI 1.19 to 3.61], p = 0.010), and permanent pacemaker (OR: 1.93 [95% CI 1.25 to 3.00], p = 0.003) were independently associated with the lack of ≥5% LVEF improvement. During a median follow-up of 3.8 (interquartile range 2.6 to 5.2) years, 176 patients died (31%). Patients with ≥5% LVEF improvement had similar outcomes compared with those with <5% LVEF improvement (log-rank p = 0.89). In conclusion, patients with severe AS and baseline LVEF <40% had the greatest improvement in LVEF at 1-year follow-up after TAVI. Coronary artery disease, myocardial infarction, and permanent pacemaker were associated with lack of LVEF improvement. However, LVEF improvement at 12 months was not associated with long-term outcomes.

Cardiac remodelling - Part 2: Clinical, imaging and laboratory findings. A review from the Study Group on Biomarkers of the Heart Failure Association of the European Society of Cardiology

In patients with heart failure, the beneficial effects of drug and device therapies counteract to some extent ongoing cardiac damage. According to the net balance between these two factors, cardiac geometry and function may improve (reverse remodelling, RR) and even completely normalize (remission), or vice versa progressively deteriorate (adverse remodelling, AR). RR or remission predict a better prognosis, while AR has been associated with worsening clinical status and outcomes. The remodelling process ultimately involves all cardiac chambers, but has been traditionally evaluated in terms of left ventricular volumes and ejection fraction. This is the second part of a review paper by the Study Group on Biomarkers of the Heart Failure Association of the European Society of Cardiology dedicated to ventricular remodelling. This document examines the proposed criteria to diagnose RR and AR, their prevalence and prognostic value, and the variables predicting remodelling in patients managed according to current guidelines. Much attention will be devoted to RR in patients with heart failure with reduced ejection fraction because most studies on cardiac remodelling focused on this setting.

Acute haemodynamic impact of transcatheter aortic valve implantation in patients with severe aortic stenosis

Aims

There are limited data about the intraprocedural haemodynamic study performed immediately before and after transcatheter aortic valve implantation (TAVI) in patients with severe aortic stenosis (AS). We aimed to evaluate the acute haemodynamic impact of TAVI in patients with severe AS and to investigate invasive and non‐invasive parameters predicting all‐cause mortality.

Methods and results

A total of 245 consecutive AS patients (43% male, mean age 80.3 ± 7.3 years) undergoing TAVI were enrolled. Intraprocedural left heart catheterization (LHC) and echocardiogram before and after TAVI were performed. The clinical endpoint was the death for any cause. LHC after TAVI revealed significant changes in aortic and left ventricular (LV) pressures, including indexes of intrinsic myocardial contractility and diastolic function such as positive dP/dT (1128.9 ± 398.7 vs. 806.3 ± 247.2 mmHg/s, P ˂ 0.001) and negative dP/dT (1310.7 ± 431.1 vs. 1075.1 ± 440.8 mmHg/s, P ˂ 0.001). Post‐TAVI echo showed a significant reduction in LV end‐diastolic (P = 0.036) and end‐systolic (P ˂ 0.001) diameters, improvement in LV ejection fraction (from 55 ± 12% to 57.2 ± 10.5%, P ˂ 0.001), and pulmonary artery systolic pressure (42.1 ± 14.2 vs. 33.1 ± 10.7 mmHg, P < 0.001). After a mean follow‐up time interval of 24 months, 47 patients died. Post‐TAVI significant aortic regurgitation at echocardiography was the only independent predictor of mortality (hazard ratio 5.592, confidence interval 1.932–16.184, P = 0.002).

Conclusions

Left heart catheterization performed immediately before and after prosthesis release offers a unique insight in the assessment of LV adaptation to severe AS and the impact of TAVI on LV, catching changes in indexes of intrinsic contractility and myocardial relaxation. Aortic regurgitation assessed by echocardiography was the only independent predictor of mortality in patients undergoing TAVI.

The Effect of TAVR on Left Ventricular and Left Atrial Mechanics in Patients with Aortic Stenosis

Background. Measures of adverse cardiac remodeling, left ventricular global longitudinal strain (LVGLS) and left atrial (LA) phasic function, are predictive of cardiac events in patients with severe aortic stenosis (AS). How these parameters of cardiac function change following TAVR requires further investigation. Methods. A number of 109 consecutive patients with symptomatic severe AS who were seen in the heart valve clinic between 2014 and 2019 for TAVR were included. All patients underwent echocardiographic assessment prior to and 30 days following TAVR, with LVGLS and LA phasic function evaluation using 2D speckle-tracking echocardiography. Heart failure hospitalization, and death were assessed at 12 months. Results. The mean age of the study cohort was 81 ± 7.3 years. Following TAVR, there was a significant reduction in NYHA class III/IV symptoms [89 (82%) vs. 12 (11%), p < 0.01], and median mean aortic valve gradient [44 mmHg (16) vs. 9 mmHg (7), p < 0.01]. There was no significant change in the median LVEF [62% (13) vs. 62% (6.0), p = 0.2]; however, the LVGLS significantly increased following TAVR [15 ± 3.5% vs. 18 ± 3.3%, p < 0.01]. The median LA reservoir, conduit and contractile function significantly improved following TAVR [22.0% (14.0) vs. 18.0% (14.0) p < 0.01, 8.9% (5.4) vs. 7.8% (4.8) p < 0.01, 12% (11.0) vs. 9.6% (11.0) p < 0.01, respectively]. The incidence of death or heart failure hospitalization at 12 months was low, and occurred in eight patients (7.3%). Conclusions. TAVR results in significant short-term reverse LV and LA remodeling, as shown by improvement in LV GLS and all three components of LA phasic function, despite no change in the LVEF. The findings indicate the possible utility of strain imaging for the assessment of global LV and LA function following TAVR.

Left Ventricular Mechanics Differ in Subtypes of Aortic Stenosis Following Transcatheter Aortic Valve Replacement

Background

Left ventricular (LV) mechanics are impaired in patients with severe aortic stenosis (AS). We hypothesized that there would be differences in myocardial mechanics, measured by global longitudinal strain (GLS) recovery in patients with four subtypes of severe AS after transcatheter aortic valve replacement (TAVR), stratified based upon flow and gradient.

Methods

We retrospectively evaluated 204 patients with severe AS who underwent TAVR and were followed post-TAVR at our institution for clinical outcomes. Speckle-tracking transthoracic echocardiography was performed pre- and post-TAVR. Patients were classified as: (1) normal-flow and high-gradient, (2) normal-flow and high-gradient with reduced LV ejection fraction (LVEF), (3) classical low-flow and low-gradient, or (4) paradoxical low-flow and low-gradient.

Results

Both GLS (−13.9 ± 4.3 to −14.8 ± 4.3, P < 0.0001) and LVEF (55 ± 15 to 57 ± 14%, P = 0.0001) improved immediately post-TAVR. Patients with low-flow AS had similar improvements in LVEF (+2.6 ± 9%) and aortic valve mean gradient (−23.95 ± 8.34 mmHg) as patients with normal-flow AS. GLS was significantly improved in patients with normal-flow (−0.93 ± 3.10, P = 0.0004) compared to low-flow AS. Across all types of AS, improvement in GLS was associated with a survival benefit, with GLS recovery in alive patients (mean GLS improvement of −1.07 ± 3.10, P < 0.0001).

Conclusions

LV mechanics are abnormal in all patients with subtypes of severe AS and improve immediately post-TAVR. Recovery of GLS was associated with a survival benefit. Patients with both types of low-flow AS showed significantly improved, but still impaired, GLS post-TAVR, suggesting underlying myopathy that does not correct post-TAVR.

Imaging Challenges in Patients with Severe Aortic Stenosis and Heart Failure: Did We Find a Way Out of the Labyrinth?

Aortic stenosis (AS) is the most frequent degenerative valvular disease in developed countries. Its incidence has been constantly rising due to population aging. The diagnosis of AS was considered straightforward for a very long time. High gradients and reduced aortic valve area were considered as "sine qua non" in diagnosis of AS until a growing body of evidence showed that patients with low gradients could also have severe AS with the same or even worse outcome. This completely changed the paradigm of AS diagnosis and involved large numbers of parameters that had never been used in the evaluation of AS severity. Low gradient AS patients may present with heart failure (HF) with preserved or reduced left ventricular ejection fraction (LVEF), associated with changes in cardiac output and flow across the aortic valve. These patients with low-flow low-gradient or paradoxical low-flow low-gradient AS are particularly challenging to diagnose, and cardiac output and flow across the aortic valve have become the most relevant parameters in evaluation of AS, besides gradients and aortic valve area. The introduction of other imaging modalities in the diagnosis of AS significantly improved our knowledge about cardiac mechanics, tissue characterization of myocardium, calcium and inflammation burden of the aortic valve, and their impact on severity, progression and prognosis of AS, not only in symptomatic but also in asymptomatic patients. However, a variety of novel parameters also brought uncertainty regarding the clinical relevance of these indices, as well as the necessity for their validation in everyday practice. The aim of this review is to summarize the prevalence of HF in patients with severe AS and elaborate on the diagnostic challenges and advantages of comprehensive multimodality cardiac imaging to identify the patients that may benefit from surgical or transcatheter aortic valve replacement, as well as parameters that may help during follow-up.

Subclinical leaflet thrombosis after transcatheter aortic valve implantation: no association with left ventricular reverse remodeling at 1-year follow-up

Hypo-attenuated leaflet thickening (HALT) of transcatheter aortic valves is detected on multidetector computed tomography (MDCT) and reflects leaflet thrombosis. Whether HALT affects left ventricular (LV) reverse remodeling, a favorable effect of LV afterload reduction after transcatheter aortic valve implantation (TAVI) is unknown. The aim of this study was to examine the association of HALT after TAVI with LV reverse remodeling. In this multicenter case–control study, patients with HALT on MDCT were identified, and patients without HALT were propensity matched for valve type and size, LV ejection fraction (LVEF), sex, age and time of scan. LV dimensions and function were assessed by transthoracic echocardiography before and 12 months after TAVI. Clinical outcomes (stroke or transient ischemic attack, heart failure hospitalization, new-onset atrial fibrillation, all-cause mortality) were recorded. 106 patients (age 81 ± 7 years, 55% male) with MDCT performed 37 days [IQR 32–52] after TAVI were analyzed (53 patients with HALT and 53 matched controls). Before TAVI, all echocardiographic parameters were similar between the groups. At 12 months follow-up, patients with and without HALT showed a significant reduction in LV end-diastolic volume, LV end-systolic volume and LV mass index (from 125 ± 37 to 105 ± 46 g/m², p = 0.001 and from 127 ± 35 to 101 ± 27 g/m², p < 0.001, respectively, p for interaction = 0.48). Moreover, LVEF improved significantly in both groups. In addition, clinical outcomes were not statistically different. Improvement in LVEF and LV reverse remodeling at 12 months after TAVI were not limited by HALT.

Determinants of changes in pulmonary artery pressure in patients with severe aortic stenosis treated by transcatheter aortic valve implantation

BACKGROUND

Elevated pulmonary artery pressure (PAP) in patients with severe aortic stenosis (AS) is a strong predictor of adverse prognosis. This study sought to assess the relation between PAP and clinical and echocardiographic parameters in elderly patients with severe AS, as well as to identify the determinants of the change in PAP after transcatheter aortic valve implantation (TAVI).

METHODS

The study included 170 subjects (age 81 ± 7 years, 45% men) with symptomatic severe AS who were treated by TAVI. They underwent a clinical evaluation and a transthoracic echocardiography before the TAVI procedure and 6 months after.

RESULTS

In a multivariable analysis, the independent predictors for baseline PAP were the body mass index (BMI) (β = 0.21, p = .006), COPD GOLD class (β = 0.20; p = .009), the E/e' ratio (β = 0.20; p = .02) and the degree of aortic regurgitation (β = 0.20; p = .01). After TAVI, there was significantly less (51% vs. 29%, p<.0001) pulmonary hypertension, defined as a tricuspid regurgitation velocity ≥2.8 m/s. The baseline variables related to an improvement in PAP were the tricuspid regurgitation velocity (p = .0001) and the E/e' (p = .005). From the parameters potentially modified with TAVI, the only independent predictor of PAP variation was the change in the E/e' ratio (β = 0.23; p = .01).

CONCLUSIONS

Independent predictors for baseline PAP in elderly patients with symptomatic AS were the BMI, GOLD class, the aortic regurgitation and the E/e' ratio. The baseline predictors for a change in PAP 6 months after TAVI were the baseline PAP and E/e', with only the change in the E/e' ratio being correlated to the change in PAP.

Impact of surgical aortic valve replacement on global and regional longitudinal strain across four flow gradient patterns of severe aortic stenosis

To evaluate the impact of surgical aortic valve replacement (SAVR) on global (GLS) and regional longitudinal strain (RLS) across four flow-gradient patterns of severe aortic stenosis (AS) 3 months after surgery. A total of 103 patients with severe AS (aortic valve area < 1.0 cm²) were examined by speckle tracking echocardiography the day before SAVR and at 3-months follow-up. Patients were stratified into four flow-gradient patterns by stroke volume index (>35 mL/m² vs. ≤35 mL/m²) and mean transaortic gradients (>40 mmhg vs. ≤40 mmhg): normal-flow, high gradient (NF/HG); low-flow, high gradient (LF/HG); normal-flow, low gradient (NF/LG); low-flow, low gradient (LF/LG). Strain analysis comprised GLS and RLS at a basal (BLS), mid-ventricular (MLS) and apical level (ALS). Patients with high gradients improved GLS (NF/HG: 16.1 ± 3.5 % vs. 17.3 ± 3.4 %, p = 0.03 and LF/HG: 15.4 ± 3.6 % vs. 16.9 ± 3.1 %, p = 0.03), BLS (NF/HG: 12.7 ± 3.1 % vs. 14.2 ± 3.1 %, p = 0.003 and LF/HG: 11.4 ± 3.2 % vs. 13.8 ± 2.7 %, p = 0.005) and MLS (NF/HG: 15.4 ± 3.3 % vs. 16.5 ± 3.3 %, p = 0.04 and LF/HG: 14.5 ± 3.1 % vs. 16.2 ± 2.7 %, p = 0.01) whereas patients with low gradients showed no improvements three months after SAVR. ALS did not change significantly in any group. Patients with high gradients demonstrated a reduction in left ventricular (LV) mass index (p < 0.001) and N-terminal pro-Brain Natriuretic Peptide levels (p < 0.001) following SAVR in contrast to patients with low gradients. Patients with high gradient severe AS improve GLS and RLS three months after SAVR with concomitant reduction of LV mass and neurohormonal activation whereas patients with low gradients do not improve longitudinal strain, LV mass or neurohormonal activation.

Impact of transcatheter aortic valve implantation on left ventricular function recovery, mass regression and outcome in patients with aortic stenosis: protocol of the TAVI-NOR prospective study

INTRODUCTION

Transcatheter aortic valve implantation (TAVI) is a widely used treatment option as an alternative to surgical aortic valve replacement in patients with severe aortic stenosis (AS) at high or intermediate surgical risk. TAVI improves symptoms, induces reverse left ventricular (LV) remodelling and increases overall survival. However, a careful patient selection is essential to achieve better outcome. Evidence on LV functional recovery and LV mass regression after TAVI based on contemporary registry data is scarce. The impact of TAVI on the arterial vasculature is also less explored.

METHOD AND ANALYSES

This is a study of 600 consecutive patients with AS who underwent a TAVI at Haukeland University Hospital, Bergen, Norway. Demographics, clinical data, arterial haemodynamics and echocardiographic parameters were prospectively collected. In the present paper, we describe the design, major scientific objectives and echocardiography imaging protocol of the TAVI-NOR (TAVI in western NORway) study. The main objectives are: To explore the impact of TAVI on cardiac structure and function in patients with severe AS, identify the echocardiographic predictors of reverse LV remodelling, assess survival benefits according to baseline risk profile, evaluate long-term therapeutic success as reflected by reduction in valvular-arterial impedance and to investigate the impact of various types of blood pressure response immediately after TAVI on clinical outcome.

ETHICS AND DISSEMINATION

The study was approved by the Regional Committees for Medical and Health Research Ethics (REK vest, ref. number 33814) and the Institutional Data Protection Services. Patients' consent was waived. The study findings will be disseminated via peer-reviewed publications and presentation in national and international scientific meetings and conferences.

TRAIL REGISTRATION NUMBER

The study was registered in the international database: ClinicalTrials.gov, Identifier: NCT04417829.

Left Atrial Strain Identifies Increased Atrial Ectopy in Patients with Beta-Thalassemia Major

Patients with beta-thalassemia major (β-ΤΜ) may develop cardiac arrhythmias through a multifactorial mechanism. The current study evaluated the association of cardiac structure and function on echocardiography with atrial ectopic burden on 24-hour tape recording in β-ΤΜ patients. This prospective study included consecutive β-ΤΜ patients. Demographic, laboratory, echocardiographic, cardiac magnetic resonance (CMR) T2* and 24-hour tape recording data were prospectively collected. The patients were classified according to the median value of premature atrial contractions (PACs) on 24-hour tape. In total, 50 β-TM patients (37.6 ± 9.1 years old, 50% male) were divided in 2 groups; PACs ≤ 24/day and > 24/day. Patients with PACs > 24/day were treated with blood transfusion for a longer period of time (39.0 ± 8.6 vs. 32.0 ± 8.9 years, p < 0.007), compared to their counterparts. Older age (OR: 1.121, 95% CI: 1.032–1.217, p = 0.007), longer duration of blood transfusion (OR:1.101, 95% CI:1.019–1.188, p = 0.014), larger LV end-diastolic diameter (OR: 4.522, 95% CI:1.009–20.280, p = 0.049), higher values of LA peak systolic strain (OR: 0.869, 95% CI: 0.783–0.964, p = 0.008), higher MV E/E′ average (OR: 1.407, 95% CI: 1.028–1.926, p = 0.033) and higher right ventricular systolic pressure (OR: 1.147, 95% CI: 1.039–1.266, p = 0.006) were univariably associated with PACs > 24/day. LA peak systolic strain remained significantly associated with PACs > 24/day after adjusting for the duration of blood transfusions or for CMR T2*. The multivariable model including blood transfusion duration and LA peak systolic strain was the most closely associated with PACs > 24/day. Receiver operating characteristic curve analysis identified a left atrial peak systolic strain of 31.5%, as the best cut-off value (83% sensitivity, 68% specificity) for prediction of PACs > 24/day. In β-TM patients, LA peak systolic strain was associated with the atrial arrhythmia burden independently to the duration of blood transfusions and CMR T2*.

Subclinical leaflet thrombosis is associated with impaired reverse remodelling after transcatheter aortic valve implantation

AIMS

Cardiac CT is increasingly applied for planning and follow-up of transcatheter aortic valve implantation (TAVI). However, there are no data available on reverse remodelling after TAVI assessed by CT. Therefore, we aimed to evaluate the predictors and the prognostic value of left ventricular (LV) reverse remodelling following TAVI using CT angiography.

METHODS AND RESULTS

We investigated 117 patients with severe, symptomatic aortic stenosis (AS) who underwent CT scanning before and after TAVI procedure with a mean follow-up time of 2.6 years after TAVI. We found a significant reduction in LV mass (LVM) and LVM indexed to body surface area comparing pre- vs. post-TAVI images: 180.5 ± 53.0 vs. 137.1 ± 44.8 g and 99.7 ± 25.4 vs. 75.4 ± 19.9 g/m2, respectively, both P < 0.001. Subclinical leaflet thrombosis (SLT) was detected in 25.6% (30/117) patients. More than 20% reduction in LVM was defined as reverse remodelling and was detected in 62.4% (73/117) of the patients. SLT, change in mean pressure gradient on echocardiography and prior myocardial infarction was independently associated with LV reverse remodelling after adjusting for age, gender, and traditional risk factors (hypertension, body mass index, diabetes mellitus, and hyperlipidaemia): OR = 0.27, P = 0.022 for SLT and OR = 0.22, P = 0.006 for prior myocardial infarction, OR = 1.51, P = 0.004 for 10 mmHg change in mean pressure gradient. Reverse remodelling was independently associated with favourable outcomes (HR = 0.23; P = 0.019).

CONCLUSION

TAVI resulted in a significant LVM regression on CT. The presence of SLT showed an inverse association with LV reverse remodelling and thus it may hinder the beneficial LV structural changes. Reverse remodelling was associated with improved long-term prognosis.

Sex differences in aortic stenosis: from pathophysiology to treatment

Introduction: In aortic stenosis (AS), there are clear sex differences in clinical presentation, left ventricular (LV) response to pressure overload, and pathophysiology of valvular calcification. These differences may affect outcome following valve intervention.Area covered: This review aims to discuss sex differences in clinical presentation, pathophysiology of aortic valve calcification, LV remodeling in view of historic and recent echocardiographic and cardiac magnetic resonance imaging studies, and outcome after valve intervention. In addition, it will also provide some brief insights on the exercise physiology in women and men with AS.Expert commentary: Women at presentation are often older, have higher prevalence of hypertension and diastolic dysfunction, while men are younger, and more often have a bicuspid aortic valve and higher atherosclerotic disease burden. Men have more valve calcification than women for a given severity of AS and develop different patterns of LV remodeling and myocardial fibrosis. Although women tend to walk shorter on treadmill and achieve lower metabolic equivalents, they achieve similar peak heart rates and blood pressure, and the frequency of revealed symptoms during exercise test is comparable in both sexes. Men are more likely to undergo a surgical AVR with better outcome, while women have generally better outcome after TAVI.

A new non-invasive index for prognosis evaluation in patients with aortic stenosis

The global left ventricular (LV) contractility index, dσ*/dt_max measures the maximal rate of change in pressure-normalized LV wall stress. We aim to describe the trend of dσ*/dt_max in differing severity of aortic stenosis (AS) with preserved left ventricular ejection fraction (LVEF) and the association of dσ*/dt_max with clinical outcomes in moderate AS and severe AS. We retrospectively studied a total of 1738 patients with AS (550 mild AS, 738 moderate AS, 450 severe AS) and preserved LVEF ≥ 50% diagnosed from 1^st January 2001 to 31^st December 2015. dσ*/dt_max worsened with increasing severity of AS despite preserved LVEF (mild AS: 3.69 ± 1.28 s^-1, moderate AS: 3.17 ± 1.09 s^-1, severe AS: 2.58 ± 0.83 s^-1, p < 0.001). Low dσ*/dt_max < 2.8 s^-1 was independently associated with a higher composite outcome of aortic valve replacement, congestive cardiac failure admissions and all-cause mortality (adjusted hazard ratio 1.48, 95% CI: 1.25-1.77, p < 0.001). In conclusion, dσ*/dt_max declined with worsening AS despite preserved LVEF. Low dσ*/dt_max < 2.8 s^-1 was independently associated with adverse clinical outcomes in moderate AS and severe AS with preserved LVEF.

Impact of stroke volume on severe aortic stenosis in patients with normal left ventricular function

BACKGROUND

Low-flow (LF) aortic stenosis (AS) with a normal ejection fraction reportedly has a worse prognosis than normal-flow (NF) AS. We assessed whether the stroke volume affects early- and long-term survival of patients with AS undergoing aortic valve replacement.

METHODS AND RESULTS

From 2007 to 2016, 179 patients with AS and a normal ejection fraction (≥ 50%) and without other valve diseases were divided into two groups according to the stroke volume index (SVI): NF group (SVI ≥ 35 ml/m², n = 167) and LF group (SVI < 35 ml/m², n = 12). Early- and long-term survival was compared between the two groups. Preoperative echocardiography showed that the end-diastolic diameter and aortic valve area were smaller in the LF than NF group (43 ± 1.9 vs. 48 ± 0.4 mm, p < 0.005 and 0.33 ± 0.14 vs. 0.49 ± 0.14 cm²/m², p < 0.0005, respectively). Hospital mortality was significantly higher (16.7% vs. 1.8%, p < 0.05) and 5-year overall survival was lower (58 ± 17 vs. 84 ± 4.2 months, p < 0.005) in the LF than NF group.

CONCLUSION

Patients with LF AS had worse operative and long-term outcomes than those with NF, even though they had preserved LV function.

Prognostic impact of postprocedure stroke volume in patients with low-gradient aortic stenosis

Objective

The effect of postoperative blood flow status on the prognosis of patients with low-gradient severe aortic stenosis (AS) has not been examined. Severe AS is associated with a higher mortality rate after transcatheter aortic valve implantation (TAVI). We examined the prognostic value of low-flow status by comparing stroke volume indices (SVi) before and after TAVI in patients with symptomatic, low-gradient severe AS.

Methods

A total of 1613 patients with severe symptomatic AS who underwent TAVI in 14 Japanese institutes for low-gradient severe AS (418 patients, median age 84 years, 32.5% men) were prospectively enrolled. The primary endpoint was cardiovascular mortality during follow-up after TAVI, and independent predictors were evaluated. Receiver operating characteristic curves were generated to determine the optimal cut-off value of post-TAVI SVi for predicting cardiovascular mortality, and the receiver operating characteristic curves of pre-TAVI and post-TAVI SVi were compared.

Results

The cardiovascular mortality rate was 4.1% (17 patients) during follow-up (median 9.2 months). Multivariate analysis revealed post-TAVI SVi to be an independent predictor of cardiovascular mortality (per 10 mL/m² decrease; HR, 2.0; 95% CI 1.28 to 3.12). The optimal cut-off value of post-TAVI SVi was 41.4 mL/m². Post-TAVI SVi showed significantly larger area under the curve than pre-TAVI SVi (0.74 (95% CI 0.69 to 0.79) vs 0.61 (95% CI 0.56 to 0.65), p<0.05).

Conclusions

Post-TAVI SVi is a better predictor of cardiovascular mortality than pre-TAVI SVi in patients with symptomatic low-gradient severe AS. Low-flow and low-normal-flow status (35≤ SVi <40 mL/m²) require careful management after TAVI.

Changes in left ventricular function in patients with aortic regurgitation 12 months after transapical transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) is an established treatment for high surgical risk aortic stenosis patients; in recent years, it has also been used in patients with pure/dominant aortic regurgitation (AR). This study aimed to determine the impact of transapical TAVI on left ventricle myocardial mechanics in AR patients. Thirty AR patients (70% men; mean age, 72.8 ± 4.3 years) were enrolled. Conventional echocardiography was performed on all patients before and 12 months after TAVI. Three-dimensional speckle tracking was accomplished in 20 AR patients for the evaluation of global longitudinal strain, global circumferential strain, twist, torsion, apical rotation and basal rotation. Preoperative left ventricular ejection fraction (LVEF), global longitudinal strain (GLS), global circumferential strain (GCS), twist, torsion and apical rotation were impaired in AR patients compared with controls. Mean left ventricular (LV) end-diastolic diameter (from 62.9 ± 7.3 to 52.0 ± 6.8 mm, p < 0.001), LV end-diastolic volume (from 199.4 ± 55.0 to 130.1 ± 48.9 mL, p < 0.001), and LV mass index (179.8 ± 52.2-134.4 ± 42.5 g/m², p = 0.001) decreased 12 months after TAVI. Interestingly, GLS (from - 17.2 ± 3.2 to - 18.9 ± 3.7, p = 0.007) and GCS (from - 23.9 ± 4.9 to - 25.7 ± 5.0, p = 0.008) improved significantly, but LVEF did not significantly improve. In terms of the rotational mechanics, twist, rotation and basal rotation remained almost unchanged, whereas apical rotation (from 7.4 ± 4.0 to 5.5 ± 3.9, p = 0.009) was significantly impaired after transapical TAVI. Our results indicate that LV function was improved in terms of myocardial deformation but worsened in terms of apical rotation 12 months after TAVI in AR patients. Three-dimensional speckle tracking echocardiography appears to be a sensitive method for detecting subtle cardiac remodeling after TAVI.

Newer echocardiographic techniques for aortic-valve imaging: Clinical aids today, clinical practice tomorrow

Increasing life expectancy is expected to lead to a corresponding increase in the prevalence of aortic valve disease (AVD). Further, the number of indications for transcatheter aortic valve replacement (TAVR) as a treatment option for AVD is expanding, with a growing role for echocardiography in its management. In this review we summarize the current literature on some newer echocardiographic modalities and the parameters they generate, with a particular focus on their prognostic and clinical value beyond conventional methods in the management of aortic stenosis, TAVR, and aortic regurgitation. Speckle tracking and 3D echocardiography are now increasingly being used in the management of AVD. For instance, global longitudinal strain, the best-studied speckle tracking echocardiographic parameter, can detect subtle subclinical cardiac dysfunction in patients with AVD that is not apparent using traditional echocardiographic techniques. The emerging technique of 3D full volume color Doppler echocardiography provides more accurate measurement of the severity of aortic regurgitation than 2D-proximal isovelocity surface area. These novel techniques are promising for evaluating and risk stratifying patients to optimize surgical interventions, predict recovery, and improve clinical outcomes.

Early Recovery of Left Ventricular Systolic Function after Transcatheter Aortic Valve Implantation

Background

A lot of studies have shown a positive effect of transcatheter aortic valve implantation (TAVI) on left ventricular ejection fraction (LVEF).

Objectives

We aimed to investigate the effect of TAVI on left ventricular function and correlate this phenomenon with hypertrophy degree in an early follow-up.

Materials and Methods

Between August 2015 and July 2016, 250 consecutive patients with symptomatic severe aortic stenosis (AS) underwent TAVI in our institution. Given the aim of this analysis, only patients with an LVEF <50%, no more than moderate mitral valve regurgitation, successful valve implantation, and 1-month follow-up available were included in the study (n = 46). Patients were enrolled in a prospective database, with clinical and echocardiographic evaluations at 1 month after TAVI.

Results

All patients had severe symptomatic AS (mean transaortic pressure gradients: 44.1 ± 13.8 mmHg and mean aortic valve area: 0.66 ± 0.19 cm²). Mean baseline LVEF was 39.3 ± 8.8%. Significant hemodynamic improvement was observed after TAVI. Mean transvalvular aortic gradient decreased significantly from 44.1 ± 13.8 mmHg to 8.9 ± 4.2 mmHg (P < 0.005). A statistically significant improvement in LVEF compared to baseline was observed in the 1^st month of follow-up (39.3 ± 8.8% vs. 44.1 ± 10.1%, P < 0.019). Overall, 52.2% of patients showed an increase in LVEF, 32.6% had no change, while only 2.2% had a decrease in LVEF. Interestingly, we found a significant reverse correlation between LVEF improvement and ventricular hypertrophy measured as diastolic interventricular septum thickness (Pearson index r = -0.42). Patients showing greater improvement in LVEF were those with less than moderate hypertrophy.

Conclusions

Patients with depressed systolic function show a consistent and early LVEF recovery after TAVI. An impaired LVEF recovery is most likely among patients with more than moderate hypertrophy, probably responsible of left ventricular fibrosis that irremediably compromises systolic function.

Reversibility of Cardiac Function Predicts Outcome After Transcatheter Aortic Valve Replacement in Patients With Severe Aortic Stenosis

Background

Reversibility of left ventricular (LV) dysfunction in high‐risk aortic stenosis patient and its impact on survival after transcatheter aortic valve replacement (TAVR) are unclear. We aimed to evaluate longitudinal changes of LV structure and function after TAVR and their impact on survival.

Methods and Results

We studied 209 patients with aortic stenosis who underwent TAVR from May 2006 to December 2012. Echocardiograms were used to calculate LV end‐diastolic volume index (LVEDVi), LV ejection fraction, LV mass index (LVMi), and global longitudinal strain before, immediately (<10 days), late (1–3 months), and yearly after TAVR. During a median follow‐up of 1345 days, 118 patients died, with 26 dying within 1 year. Global longitudinal strain, LVEDVi, LV ejection fraction, and LVMi improved during follow‐up. In patients who died during the first year, death was preceded by LVEDVi and LVMi increase. Multivariable longitudinal data analysis showed that aortic regurgitation at baseline, aortic regurgitation at 30 days, and initial LVEDVi were independent predictors of subsequent LVEDVi. In a joint analysis of longitudinal and survival data, baseline Society of Thoracic Surgeons score was predictive of survival, with no additive effect of longitudinal changes in LVEDVi, LVMi, global longitudinal strain, or LV ejection fraction. Presence of aortic regurgitation at 1 month after TAVR was the only predictor of 1‐year survival.

Conclusions

LV reverse remodeling was observed after TAVR, whereas lack of LVEDVi and LVMi improvement was observed in patients who died during the first year after TAVR. Post‐TAVR, aortic regurgitation blocks reverse remodeling and is associated with poor 1‐year survival after TAVR.

Impact of Prosthesis-Patient Mismatch on Left Ventricular Myocardial Mechanics After Transcatheter Aortic Valve Replacement

Background

The aim of this study was to compare left ventricular (LV) remodeling using myocardial strain between patients with severe aortic stenosis (AS) treated with transcatheter aortic valve replacement (TAVR) with and without prosthesis‐patient mismatch (PPM).

Methods and Results

In a retrospective study, speckle‐tracking echocardiography was used to measure global longitudinal strain (GLS) and strain rate (GLSR), circumferential strain, and rotation before and at mid‐term follow‐up post‐TAVR. Moderate and severe PPM were defined as an effective orifice area ≤0.85 and <0.65 cm²/m², respectively. A total of 102 patients (median age, 83 years [77–88]) with severe AS were included. At 6±3 months post‐TAVR, moderate and severe PPM were found in 32 (31%) and 9 (9%) patients. Patients without PPM had a significant regression in LV mass (from 134±41 to 119±38 g/m²; P=0.001) at follow‐up whereas those with PPM did not. There was a significant improvement in LV GLS (−12.8±4.0 to −14.3±4.3%; P=0.01), GLSR (−0.61±0.20 to −0.73±0.25 second⁻¹; P<0.001), and early diastolic strain rate (0.52±0.20 to 0.64±0.20 second⁻¹; P<0.001) in patients without PPM, but not in those with PPM. After adjustment for pre‐TAVR ejection fraction and post‐TAVR aortic regurgitation, patients without PPM had greater improvement in LV longitudinal strain parameters compared to those with PPM. After a median follow‐up of 46.1 months (interquartile range, 35.4–60.8), there was no difference in survival between patients with and without PPM.

Conclusions

TAVR was associated with an incidence of PPM of 40%. Greater reverse LV remodeling using myocardial strain was evident in patients without PPM compared to PPM. Presence of PPM was not associated with mortality.

Recent advances in echocardiography for valvular heart disease

Echocardiography is the imaging modality of choice for the assessment of patients with valvular heart disease. Echocardiographic advancements may have particular impact on the assessment and management of patients with valvular heart disease. This review will summarize the current literature on advancements, such as three-dimensional echocardiography, strain imaging, intracardiac echocardiography, and fusion imaging, in this patient population.

Safety, Feasibility, and Hemodynamic Effects of Mild Hypothermia in Transcatheter Aortic Valve Replacement: The TAVR-CHILL Trial

The safety, feasibility, and hemodynamic effects of mild hypothermia (MH) induced by transnasal cooling were studied in transcatheter aortic valve replacement (TAVR). MH is a common therapy following cardiac arrest and seems to have favorable effects in myocardial infarction and on hemodynamic stability. In TAVR, hemodynamic instability is common during rapid pacing. Twenty subjects undergoing TAVR were randomized 1:1 to hypothermia or normothermia. Hemodynamic endpoints were mean arterial blood pressure and required dosage of vasoactive and inotropic drugs. Patients were followed up at 6 months. All patients in the MH group (n=10) reached the target temperature of 34°C before first rapid pacing. Tympanic and urinary bladder temperature remained significantly lower in the MH group during the procedure. No adverse effects of cooling were observed. Mean arterial pressure was higher in the MH group (90±20 mm Hg) than in the control group (71±13 mm Hg) at the start of the procedure, at first rapid pacing (94±19 vs. 80±16 mm Hg), and at balloon aortic valvuloplasty (90±17 vs. 73±14 mm Hg). Less norepinephrine was administered to the hypothermia group. Transnasal cooling during TAVR was safe and well tolerated. We observed a more stable hemodynamic profile in the MH group, indicated by higher blood pressure and lower levels of vasoactive drugs required. A larger study of patients with severe ventricular dysfunction is required to more comprehensively investigate the hemodynamic effects of transnasal cooling in TAVR.

Impact of classic and paradoxical low flow on survival after aortic valve replacement for severe aortic stenosis

BACKGROUND

Low flow (LF) can occur with reduced (classic) or preserved (paradoxical) left ventricular ejection fraction (LVEF).

OBJECTIVES

The objective of this study was to compare outcomes of patients with low ejection fraction (LEF), paradoxical low flow (PLF), and normal flow (NF) after aortic valve replacement (AVR).

METHODS

We examined 1,154 patients with severe aortic stenosis (AS) who underwent AVR with or without coronary artery bypass grafting.

RESULTS

Among these patients, 206 (18%) had LEF as defined by LVEF of <50%; 319 (28%) had PLF as defined by LVEF of ≥50% but stroke volume indexed to body surface area (SVi) of ≤35 ml ∙ m(-2); and 629 (54%) had NF, as defined by LVEF of ≥50% and SVi of >35 ml ∙ m(2). Aortic valve area was lower in low flow/LVEF groups (LEF: 0.71 ± 0.20 cm(2) and PLF: 0.65 ± 0.23 cm(2) vs. NF: 0.77 ± 0.18 cm(2); p < 0.001). The 30-day mortality was higher (p < 0.001) in LEF and PLF groups than in the NF group (6.3% and 6.3% vs. 1.8%, respectively). SVi and PLF group were independent predictors of operative mortality (odds ratio [OR]: 1.18, p < 0.05; and OR: 2.97, p = 0.004; respectively). At 5 years after AVR, overall survival was 72 ± 4% in LEF group, 81 ± 2% in PLF group, and 85 ± 2% in NF group (p < 0.0001).

CONCLUSIONS

Patients with LEF or PLF AS have a higher operative risk, but pre-operative risk score accounted only for LEF and lower LVEF. Patients with LEF had the worst survival outcome, whereas patients with PLF and normal flow had similar survival rates after AVR. As a major predictor of perioperative mortality, SVi should be integrated in AS patients' pre-operative evaluation.