Low-flow Low-gradient Aortic Stenosis Research Articles

Comprehensive assessment of the aortic valve in critically ill patients for the non-cardiologist. Part I: Aortic stenosis of the native valve.

Aortic stenosis (AS) causes left ventricular outflow obstruction. Severe AS has major haemodynamic implications in critically ill patients, in whom increased cardiac output and oxygen delivery are often required. Transthoracic echocardiography (TTE) plays akey role in the AS severity grading. In this review, we will give an overview of how to use the simplified Bernoulli equation to convert the echo Doppler measured velocities (cm s-1) to AS peak and mean gra-dient (mm Hg) and how to calculate the aortic valve area (AVA), using the continuity equation, based on the principle of preservation of flow. TTE allows quantification of compensatory left ventricular (LV) hypertrophy, assessment of LV systolic function, and determination of LV diastolic function and LV loading. Subsequently, the obtained results from the TTE study need to be integrated to establish the AS severity grading. The pitfalls of echocardiographic AS severity assessment are explained, and how to deal with inconsistency between AVA and mean gradient. The contribution of transoesophageal echocardiography, low-dose dobutamine stress echo (in case of low-flow low-gradient AS), echocardiography strain imaging, cardiac magnetic resonance imaging, cardiac multidetector computed tomography and the relatively new concept of Flow Pressure Gradient Classification to the work-up for aortic stenosis is discussed. Finally, the treatment of AS is overviewed. Elective aortic valve replacement is indicated in patients with severe symptomatic AS. In the ICU, afterload reduction by vasodilator therapy and treatment of pulmonary and venous congestion by diuretics could be considered.

Patient survival in severe low-flow, low-gradient aortic stenosis after aortic valve replacement or conservative management.

Background and aimClassical and paradoxical low‐flow, low‐gradient (LFLG) aortic stenosis (AS) are the most challenging subtypes of AS. The current therapeutic options are aortic valve replacement (AVR) and conservative management: AVR promotes long‐term survival but is invasive, while conservative management yields a poor prognosis but is noninvasive since it uses no aortic valve replacement (noAVR). The present meta‐analysis investigated the rate of survival of patients with LFLG AS undergoing either AVR or noAVR interventions.MethodsThe meta‐analysis compared the outcomes of AVR with those of noAVR in terms of patient survival. In both groups, a meta‐regression was conducted to investigate the impact on patient survival of the left ventricular ejection fraction (LVEF), either preserved (paradoxical LFLG AS) or reduced (classical LFLG AS).ResultsThe relative risk of survival between the AVR and noAVR groups was 1.99 [1.40, 2.82] (p = .0001), suggesting that survival tends to be better in AVR patients than in noAVR patients. The meta‐regression revealed that a reduced LVEF may be related to a higher survival in AVR patients when compared to a preserved LVEF (p = .04). Finally, the analysis indicated that LVEF seems not to be prognostic of survival in noAVR patients (p = .18).ConclusionsPatients with LFLG AS have better survival if they undergo AVR. In AVR patients, reduced LVEF rather than preserved LVEF is related to better survival, whereas there seems to be no difference in prognostic value between reduced and preserved LVEF in noAVR patients.

Prognosis of paradoxical low-flow low-gradient aortic stenosis after transcatheter aortic valve replacement.

In paradoxical low-flow low-gradient severe aortic stenosis (PLFLG AS) patients, stroke volume index (SVI) is reduced despite preserved left ventricular ejection fraction (LVEF). Although reduced SVI is already known as a poor prognostic predictor, the outcomes of PLFLG AS patients after transcatheter aortic valve replacement (TAVR) have not been clearly defined. We retrospectively investigated the post-TAVR outcomes of PLFLG AS patients in comparison with normal-flow high-gradient aortic stenosis (NFHG AS) patients. The current observational study included 245 patients with NFHG AS (mean transaortic pressure gradient ≥40 mmHg and LVEF ≥ 50%) and 48 patients with PLFLG AS (mean transaortic pressure gradient <40 mmHg, LVEF ≥ 50% and SVI < 35 ml/m2). The endpoints were all-cause mortality, hospitalization for valve-related symptoms or worsening congestive heart failure and New York Heart Association functional class III or IV. PLFLG AS patients had a significantly higher proportion with a history of atrial fibrillation/flutter as compared with NFHG AS patients. All-cause mortality of PLFLG AS patients was worse than that of NFHG AS patients (P = 0.047). Hospitalization for valve-related symptoms or worsening congestive heart failure was more frequent in PLFLG AS patients than in NFHG AS patients (P = 0.041). New York Heart Association functional class III-IV after TAVR was more frequently observed in PLFLG AS patients (P = 0.019). The outcomes of PLFLG AS patients were worse than those of NFHG AS patients in this study. Preexisting atrial fibrillation/flutter was frequent in PLFLG AS patients, and may affect their post-TAVR outcomes. Therefore, closer post-TAVR follow-up should be considered for these patients.

Abstract 14646: Left Ventricular Global Longitudinal Strain and CT Derived Extracellular Volume Predicts Outcomes in Patients With Low-flow, Low-gradient Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement

Introduction: Low-flow, low-gradient aortic stenosis (LFLG-AS) is associated with impaired left ventricular (LV) function and afterload mismatch. Indications and timing for transcatheter aortic valve replacement (TAVR) in LFLG-AS do not account for the presence of subclinical LV remodeling. We evaluated whether combining LV global longitudinal strain (GLS) and CT-derived extracellular volume (ECV), both markers of LV remodeling, provides incremental prediction of adverse outcomes in patients with LFLG-AS undergoing TAVR. Methods: We retrospectively evaluated patients with LFLG-AS undergoing TAVR in whom pre-TAVR CT-based ECV measurements were available. GLS was measured in pre-TAVR echocardiograms using speckle tracking. Cox regression analysis was performed with a primary outcome of heart failure hospitalization (HFH) or death. Four sub-groups were identified for analysis based on optimal cutoff points: Group 1 (n=64): ECV&lt; 33 + GLS≥

Haemodynamic Patterns of Severe Aortic Stenosis

The authors present up-to-date review of clinical pathophysiology of aortic stenosis (AS) based on differentiation of its haemodynamic patterns, and some actual issues of instrumental diagnostics and classification of AS. The variety of clinical presentations of AS is based on diverse combination of pathological changes of haemodynamics. In Russian cardiology, there is no clear pathophysiological classification of AS despite of its relevance under the progress of surgical and transcatheter treatment of AS. The authors suggest the pilot haemodynamic classification of AS which includes 6 types (0-5) based on different combination of the following variables: left ventricle ejection fraction, stroke volume, mean aortic systolic pressure gradient. Severe AS with low transaortic pressure gradient in patients with depressed systolic function of the left ventricle (so called «low flow-low» gradient phenomenon) is referred to as the most frequent, classical haemodynamic pattern of low-gradient AS. The prevalence of this variant is about 10% among European population of patients with severe AS. The inconsistence between aortic valve area and mean pressure gradient is as common as in 35-40% of patients with AS, however, in 30-50% of these cases, AS is not severe. Severe AS is a surgical disease that should be treated in a surgical way in all patients but those in whom predicted risk overbalances potential benefits of the procedure. The use of integrated clinical and instrumental approach for identification of a true sever AS is the matter of great concern, as both overestimation and underestimation can misguide the clinical decision-making process. Verification of severe AS in patients with classical and paradoxical low flow-low gradient AS with specific indications for surgical treatment regarded is further emphasized in the paper. Since transcatheter aortic valve implantation has become a commonly recognized alternative to surgical aortic valve replacement, its role in the treatment of severe AS with different haemodynamic patterns is also discussed. The authors stress on the necessity of using tailored approach for treatment of AS regarding different clinical and pathophysiological scenarios: high gradient AS with preserved ejection fraction, classical and paradoxical low flow-low gradient AS.

Non-invasive quantitative characterization of aortic valve tissue composition from computed tomography angiography improves patient risk stratification in transcatheter aortic valve implantation

Abstract Background Computed tomography angiography (CTA) performed for procedural planning of transcatheter aortic valve implantation (TAVI) can be used for a more complete characterization of aortic valve tissue beyond calcium assessment. Combining quantitative data on both noncalcified and calcified tissues may improve differentiation of aortic stenosis (AS) subtypes and prognostication post-TAVI. Purpose We sought to noninvasively assess aortic valve tissue composition with quantitative cardiac CTA in patients with AS and its prognostic vaalue in those who underwent TAVI. Methods In 185 consecutive AS patients in a prospective registry who underwent cardiac CTA before TAVR and 90 matched controls with normal aortic valves, non-luminal aortic valve tissue were identified using semi-automated software as non-calcified (low-attenuation [−30 to 30 Hounsfield Units (HU)], fibro-fatty (31 to 130 HU), fibrous (131 to 350 HU) and calcified (&amp;gt;650 HU) tissue; with total tissue as (non-calcified + calcified components). Volumes of each component and composition [(tissue component volume/total tissue volume) ×100%] were quantified. The association of aortic valve composition and clinical outcomes post-TAVI including all-cause mortality was evaluated using Valve Academic Research Consortium (VARC)-2 definitions. Results AS patients had greater aortic valve tissue volume (median 2000.2, vs 527.8 mm3, p&amp;lt;0.001) with a higher calcified tissue composition (41.8% vs 3.4%, p&amp;lt;0.001) compared to controls. Total aortic valve tissue (noncalcified and calcified) volume yielded the highest area under the operating curve (AUC) for diagnosing severe AS (0.93,95% CI:0.93–0.99) as compared to calcified tissue volume alone (0.87,95% CI:0.81–0.94, p=0.002). Low-flow low-gradient AS was associated with increase in total tissue volume compared to controls (1515.3 vs 527.8 mm3, p&amp;lt;0.001), with lower volumes of calcified tissue than high-gradient AS (412.5 vs 829.6 mm3, p&amp;lt;0.001). Device success was achieved in 88% (164 of 185) patients and prevalence of moderate or severe paravalvular leak was 3.8%, however no differences between in aortic valve composition were observed in patients with and without device success. Early safety endpoints occurred in 16.1% (29 of 180) patients and 30-day all-cause mortality was 4.4%. Whereas only calcified tissue volume was related to VARC-2 early safety, AUC for prediction of 30-day mortality post-TAVI was 0.793 (95% CI:0.685–0.901) for total tissue volume and 0.776 (95% CI:0.676–0.876) for calcified tissue volume. Conclusions Quantitative CTA assessment of aortic valve tissue volume and composition can improve identification of high-gradient AS and low-flow low-gradient AS patients referred for TAVI and predict 30-day mortality post-TAVI. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Heart, Lung, and Blood Institute (NHLBI)

Use and success evaluation of percutaneous aortic balloon valvuloplasty in different hemodynamic entities of severe aortic stenosis in the TAVR era

Abstract Background In the era of transcatheter aortic valve replacement (TAVR), there is renewed interest in percutaneous balloon aortic valvuloplasty (BAV), which may qualify as the primary treatment option of choice in special clinical situations. Success of BAV is commonly defined as a significant mean pressure gradient reduction after the procedure. Purpose To evaluate the correlation of the mean pressure gradient reduction and increase in the aortic valve area (AVA) in different flow and gradient patterns of severe aortic stenosis (AS). Methods Consecutive patients from 01/2010 to 03/2018 undergoing BAV were divided into normal-flow high-gradient (NFHG), low-flow low-gradient (LFLG) and paradoxical low-flow low-gradient (pLFLG) AS. Baseline characteristics, hemodynamic and clinical information were collected and compared. Additionally, the clinical pathway of patients (BAV as a stand-alone procedure or BAV as a bridge to aortic valve replacement) was followed-up. Results One-hundred-fifty-six patients were grouped into NFHG (n=68, 43.5%), LFLG (n=68, 43.5%) and pLFLG (n=20, 12.8%) AS. Underlying reasons for BAV and not TAVR/SAVR as the primary treatment option are displayed in Figure 1. Spearman correlation revealed that the mean pressure gradient reduction had a moderate correlation with the increase in the AVA in patients with NFHG AS (r: 0.529, p&amp;lt;0.001) but showed no association in patients with LFLG (r: 0.145, p=0.239) and pLFLG (r: 0.030, p=0.889) AS. Underlying reasons for patients to undergo BAV and not TAVR/SAVR varied between groups, however cardiogenic shock or refractory heart failure (overall 46.8%) were the most common ones. After the procedure, independent of the hemodynamic AS entity, patients showed a functional improvement, represented by substantially lower NYHA class levels (p&amp;lt;0.001), lower NT-pro BNP levels (p=0.003) and a numerical but non-significant improvement in other echocardiographic parameters like the left ventricular ejection fraction (p=0.163) and tricuspid annular plane systolic excursion (TAPSE, p=0.066). An unplanned cardiac re-admission due to heart failure was necessary in 23.7% patients. Less than half of the patients (44.2%) received BAV as a bridge to TAVR/SAVR (median time to bridge 64 days). Survival was significantly increased in patients having BAV as a staged procedure (log-rank p&amp;lt;0.001). Conclusion In daily clinical practice, the mean pressure gradient reduction might be an adequate surrogate of BAV success in patients with NFHG AS but is not suitable for patients with other hemodynamic entities of AS. In those patients, TTE should be directly performed in the catheter laboratory to correctly assess the increase of the AVA. BAV as a staged procedure in selected clinical scenarios increases survival and is a considerable option in all flow states of severe AS. (NCT04053192) Figure 1 Funding Acknowledgement Type of funding source: None

The adverse impact of HFpEF in patients with aortic stenosis: evaluation of the H2FPEF score for risk assessment among patients with preserved ejection fraction undergoing TAVI

Abstract Background The H2FPEF score enables identification of patients with high probability of prevalent heart failure with preserved ejection fraction (HFpEF). High H2FPEF scores have proven to be associated with adverse outcome in patients with known HFpEF. Objective The aim of this study was to assess the prognostic impact of the H2FPEF score in patients undergoing Transcatheter Aortic Valve Implantation (TAVI) for severe aortic stenosis (AS) and preserved left ventricular ejection fraction (EF). Methods In this multi-centre study a total of 832 patients from two German high-volume centres, who received TAVI for severe AS and preserved EF (≥50%), were identified for calculation of the H2FPEF score. Score variables included BMI &amp;gt;30 kg/m2, arterial hypertension, atrial fibrillation, systolic pulmonary artery pressure &amp;gt;31 mmHg, age &amp;gt;60 years, and invasively assessed elevated LV filling pressure. Patients were dichotomized according to low (1–5 points; n=570) and high H2FPEF scores (6–9 points; n=262). Kaplan-Meier and Cox regression analyses were applied to assess the prognostic impact of the H2FPEF score. Median follow-up time was 1.08 years. Results Patients presenting with high H2FPEF scores had higher prevalence of moderate to severe mitral and tricuspid regurgitation compared to those with low H2FPEF scores. Stroke volume index (SVI) (Figure 1A) and mean transvalvular gradient (Pmean) consistently decreased with increasing H2FPEF score. All-cause mortality 30 days after TAVI was significantly higher in patients with high H2FPEF scores (p&amp;lt;0.0001). This finding was consistent both after 1 year (p&amp;lt;0.0001) and 3 years (p&amp;lt;0.0001) (Figure 1B). Multivariate analysis revealed a high H2FPEF score to be independently predictive for all-cause mortality (HR 1.62, 95% CI: 1.11–2.38, p=0.013). Among the single H2FPEF score parameters atrial fibrillation was the strongest independent predictor of adverse outcome. Conclusion An elevated H2FPEF score of ≥6 is independently predictive for mortality in patients with preserved EF undergoing TAVI for severe AS, which might be due to a higher proportion of paradoxical low flow low gradient AS in these patients. Our findings provide evidence that the H2FPEF score may help identify AS patients with preserved ejection fraction that are at higher risk for adverse outcome after TAVI. Spline/SVI (A) and 3y-mortality KM (B) Funding Acknowledgement Type of funding source: None

Aortic Valve Stenosis

Valvular heart disease is a common clinical syndrome that physicians face on a routine basis. Aortic stenosis (AS) accounts for a substantial amount of these cases with differing etiologies from rheumatic, congenital bicuspid to calcific AS. Clinical history and physical examination can assist in assessing the presence and severity of AS, but echocardiography has been the gold standard for the diagnosis of AS and to assess severity. Multimodality imaging including cardiac computed tomography, magnetic resonance imaging, and 3D printing have evolved over the years, lending aid in the diagnosis and prognostication of AS. This review provides a succinct overview of the prevalence, pathophysiology, clinical assessment, and diagnosis of AS. This review contains 10 figures, 3 tables and 49 references. Key Words: aortic stenosis, cardiac computed tomography, cardiac magnetic resonance imaging, 3D printing, low-flow low-gradient aortic stenosis

Aortic Valve Stenosis

Valvular heart disease is a common clinical syndrome that physicians face on a routine basis. Aortic stenosis (AS) accounts for a substantial amount of these cases with differing etiologies from rheumatic, congenital bicuspid to calcific AS. Clinical history and physical examination can assist in assessing the presence and severity of AS, but echocardiography has been the gold standard for the diagnosis of AS and to assess severity. Multimodality imaging including cardiac computed tomography, magnetic resonance imaging, and 3D printing have evolved over the years, lending aid in the diagnosis and prognostication of AS. This review provides a succinct overview of the prevalence, pathophysiology, clinical assessment, and diagnosis of AS. This review contains 10 figures, 3 tables and 49 references. Key Words: aortic stenosis, cardiac computed tomography, cardiac magnetic resonance imaging, 3D printing, low-flow low-gradient aortic stenosis

Prognostic Value of Computed Tomography–Derived Extracellular Volume in TAVR Patients With Low-Flow Low-Gradient Aortic Stenosis

ObjectivesThe association between extracellular volume (ECV) measured by computed tomography angiography (CTA) and clinical outcomes was evaluated in low-flow low-gradient (LFLG) aortic stenosis (AS) patients undergoing transcatheter aortic valve replacement (TAVR). BackgroundPatients with LFLG AS comprise a high-risk group with respect to clinical outcomes. Although ECV, a marker of myocardial fibrosis, is traditionally measured with cardiac magnetic resonance, it can also be measured using cardiac CTA. The authors hypothesized that in LFLG AS, increased ECV may be associated with adverse clinical outcomes. MethodsIn 150 LFLG patients with AS who underwent TAVR, ECV was quantified using pre-TAVR CTA. Echocardiographic and clinical information including all-cause death and heart failure rehospitalization (HFH) was obtained from electronic medical records. A Cox proportional hazards model was used to evaluate the association between ECV and death+HFH. ResultsDuring a median follow-up of 13.9 months (range 0.07 to 28.9 months), there were 31 death+HFH events (21%). Patients who experienced death+HFH had a greater median Society of Thoracic Surgery score (9.9 vs. 4.7; p < 0.01), lower left ventricular ejection fraction (42.3 ± 20.2% vs. 52.7 ± 17.2%; p < 0.01), lower mean transvalvular gradient (24.9 ± 8.9 mm Hg vs. 28.1 ± 7.3 mm Hg; p = 0.04) and increased mean ECV (35.5 ± 9.6% vs. 29.9 ± 8.2%; p < 0.01) compared with patients who did not experience death+HFH. In a multivariable Cox proportional hazards model, increase in ECV was associated with increase in death+HFH, (hazard ratio per 1% increase: 1.04, 95% confidence interval: 1.01 to 1.09; p < 0.01). ConclusionsIn patients with LFLG AS, CTA measured increase in ECV is associated with increased risk of adverse clinical outcomes post-TAVR and may thus serve as a useful noninvasive marker for prognostication.

Risk of mortality following transcatheter aortic valve replacement for low-flow low-gradient aortic stenosis.

Low-flow low-gradient (LF-LG) aortic stenosis (AS) is associated with high mortality, even after transcatheter aortic valve replacement (TAVR). Further knowledge of risk indicators is needed and a clinical risk score would be desirable for optimizing patient selection and therapeutic strategy. The study cohort comprised of 219 consecutive LF-LG AS patients undergoing TAVR from 2008 to 2018 in two high-volume German centers. Predictive factors for one-year all-cause mortality were defined according to a Cox proportional hazard model. At one-year follow-up after TAVR, 28% of patients had died. A multivariate model revealed six independent predictors of one-year mortality: history of myocardial infarction (HR 2.05, 95%CI 1.13-3.72), eGFR < 30ml/min/1.73m2 (HR 2.75, 95%CI 1.48-5.11), tricuspid regurgitation moderate or more (HR 2.06, 95%CI 1.14-3.72), stroke volume index < 25mL/m2 (HR 2.03, 95%CI 1.14-3.62), self-expandable device (HR 2.72, 95%CI 1.17-6.27), and non-transfemoral approach (HR 3.42, 95%CI 1.28-9.14). The Rhineland Risk Score (RRS) consisting of these variables (c statistic 0.75, 95%CI 0.68-0.82, p < 0.001) was superior to the EuroSCORE II (c statistic 0.63) and STS-PROM score (c statistic 0.69) at predicting one-year mortality. Patients with a RRS ≥ 8 had a prohibitive risk of one-year mortality of 67.6% (95%CI 52.0-82.4%). In patients with LF-LG AS, history of myocardial infarction, renal dysfunction, tricuspid regurgitation, a low stroke volume index, self-expandable device, and non-femoral approach were associated with increased 1-year mortality after TAVR. The RRS might serve as a helpful tool for risk prediction and patient selection for TAVR in patients with LF-LG AS.

The clinical significance of the incorporation of tissue Doppler imaging into low-dose Dobutamine stress echocardiography in patients with aortic stenosis prior to Transcatheter aortic valve implantation

BackgroundLow-dose dobutamine stress echocardiography (DSE) is indicated in patients with low flow (stroke volume index [SVi] < 35 ml/m2) low gradient (mean pressure gradient < 40 mmHg) and left ventricular ejection fraction (LVEF) < 50% aortic stenosis (AS) to assess LV contractile reserve (> 20% increase in SVi) and severity grade of AS. Severe AS is defined by a mean pressure gradient of 40 mmHg occurring at any time during the test when aortic valve area remains < 1.0 cm2.Case presentationThis case report highlights the utility of mitral annular systolic velocity (S′) by tissue Doppler imaging and peak LV outflow tract (LVOT) velocity as markers of LV intrinsic contractile function during DSE in a patient with low flow low gradient AS and reduced EF prior to transcatheter aortic valve implantation (TAVI).ConclusionsMitral annular S′ and peak LVOT velocities are reliable markers of LV intrinsic contractile function and should be incorporated into routine low-dose DSE.

Echocardiographic findings on aortic stenosis: an observational, prospective, and multi-center registry.

The aim of this aortic stenosis registry was to investigate the changes of routine echocardiographic indices and strain in patients with moderate-to-severe aortic stenosis over a 6-month follow-up period. Our aortic stenosis registry is observational, prospective, multicenter registry of nine countries, with 197 patients with aortic valve area less than 1.5 cm2. The enrolment took place from January to August 2017. We excluded patients with uncontrolled atrial arrhythmias, pulmonary hypertension or cardiomyopathies, as well as those with hemodynamically significant valvular disease other than aortic stenosis. We included patients who did not require intervention and who had a complete follow-up study. In patients with preserved ejection fraction, left ventricular mass has significantly increased between baseline and follow-up studies (218 ± 34 grams vs 253 ± 29 grams, p = 0.02). However, when indexed to body surface area, there was no significant difference. Left ventricular global longitudinal strain significantly decreased (-19.7 ± -4.8 vs (-16.4 vs -3.8, p = 0.01). Left atrial volume was significantly higher at follow-up (p = 0.035). Right ventricular basal diameter and mid-cavity diameter were greater at the follow-up (p = 0.04 and p = 0.035, respectively). Patients with low-flow low-gradient aortic stenosis had significantly lower global longitudinal strain (-12.3% ± -3.9% vs -19.7% ± -4.8%, p = 0.01). Left atrial dilatation is one of the first changes to take place in low-flow low-gradient aortic stenosis patients even when left ventricular dimensions and function remains intact. Global longitudinal strain is an important determinant of left ventricular systolic and diastolic dysfunction and right ventricular function is an important parameter of aortic stenosis assessment. Accordingly, our registry has further shed the light on these indices role as multisite follow-up of aortic stenosis.

What Is New in Low Gradient Aortic Stenosis: Surgery, TAVR, or Medical Therapy?

A significant proportion of patients with aortic stenosis (AS) have discordance in severity by mean gradient/peak velocity and aortic valve area. Low gradient aortic stenosis (LG-AS) is defined when the aortic valve area is < 1cm2 consistent with severe AS and mean aortic gradient is < 40mmHg consistent with non-severe AS. LG-AS represents a diagnostic and therapeutic challenge. To summarize the different categories, diagnosis, management, and prognosis of LG-AS. LG-AS is classified as classical (ejection fraction (EF) < 50%, indexed stroke volume (SVi) < 35ml/m2), paradoxical (EF > 50%, SVi < 35ml/m2), pseudo-severe (moderate AS with reduced EF), or normal flow low gradient AS. Recent findings emphasize the importance of low-dose dobutamine stress echocardiography and CT calcium score in the assessment of aortic valve. In addition, flow reserve (increase in SV > 50%) can be evaluated during dobutamine stress echocardiography and helps predict perioperative prognosis. Patients with LG-AS have better survival with aortic valve replacement (AVR) compared to medical therapy, irrespective of presence or absence of flow reserve. Some recent studies suggest that transcatheter aortic valve replacement (TAVR) may be superior to surgical AVR for patients with a lack of contractile flow reserve or those with paradoxical LG-AS, but further investigation is needed to clarify optimal treatment. The role of TAVR in patients with moderate AS and reduced EF is also under investigation.

In the midst of a dangerous intersection with unclear therapeutic strategies: a challenging case of severe aortic stenosis

BackgroundOne out of seven patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR) may be affected by transthyretin cardiac amyloidosis (ATTR-CA), mostly presenting with low-flow low-gradient AS with mildly reduced ejection fraction. The complex interaction of these two pathologies poses specific diagnostic and management challenges. The prognostic implications of this clinical intersection are not defined yet. Moreover, whether TAVR may have a prognostic benefit in ATTR-CA patients with symptomatic severe AS remains unclear, posing doubts on the best management strategy in this increasingly recognized subset of patients.Clinical caseWe present a case of an 87-year old man with low-flow low-gradient severe AS, for whom a diagnosis of ATTR-CA was suspected based on clinical and echocardiographic criteria specific to coexisting AS and ATTR-CA. The diagnosis was eventually confirmed by positive bone tracer scintigraphy imaging. Following in-depth Heart team discussion, integrating frailty and prognostic information from combined cardiomyopathy states, a decision was made to manage the patient’s severe AS conservatively.ConclusionIn the presented case, we deemed the natural history of ATTR-CA amyloidosis to negatively affect both the patient’ prognosis and procedural risk, adversing TAVR indication despite symptomatic severe AS. No clear evidence is currently available to guide decision making in this setting, advocating for prospective studies to clarify if TAVR may have a prognostic benefit in ATTR-CA - and which ATTR-CA - patients.

Clinical application of stress echocardiography in valvular heart disease: an expert consensus of the Working Group on Valvular Heart Disease of the Polish Cardiac Society.

Valvular heart diseases (VHDs) constitute an increasing problem both as a consequence of population aging and as the sequelae of other heart diseases. Accurate diagnosis is essential for correct clinical decision‑making; however, in many patients, transthoracic and transesophageal echocardiography is insufficient. Stress echocardiography (SE) proved to be a useful tool allowing for simultaneous assessment of left ventricular contractile reserve and HVD hemodynamics under conditions of physiological or pharmacological stress. It is recommended for assessing the severity of VHD, guiding the choice of treatment, as well as for surgical risk stratification. It can be applied both in asymptomatic patients with severe VHD and in symptomatic individuals with moderate disease. In patients with VHD, SE can be performed either as exercise stress echocardiography (ESE) or dobutamine stress echocardiography (DSE). The first modality is recommended to unmask symptoms or abnormal blood pressure response in patients with aortic stenosis (AS) who report to be asymptomatic or in those with mitral stenosis with discordance between clinical symptoms and the severity of valve disease on transthoracic echocardiography. In asymptomatic patients with paradoxical low‑flow, low‑gradient (LFLG) AS, ESE can be used to assess the severity of stenosis. On the other hand, low‑dose DSE can be a useful diagnostic tool in classical LFLG AS, providing information on stenosis severity and contractile reserve. Moreover, SE is indicated in patients with prosthetic valve when there is discordance between symptoms and echocardiographic findings. It is also recommended in high‑risk surgical patients with VHD with poor functional capacity and more than 2 clinical risk factors. The present paper discusses in detail the use of SE in VHD.

Usefulness of Cardiac Magnetic Resonance Imaging in Aortic Stenosis.

The objective of this review is to provide an overview of the role of cardiac magnetic resonance (CMR) in aortic stenosis (AS). Although CMR is undeniably the gold standard for assessing left ventricular volume, mass, and function, the assessment of the left ventricular repercussions of AS by CMR is not routinely performed in clinical practice, and its role in evaluating and quantifying AS is not yet well established. CMR is an imaging modality integrating myocardial function and disease, which could be particularly useful in a pathology like AS that should be considered as a global myocardial disease rather than an isolated valve disease. In this review, we discuss the emerging potential of CMR for the diagnosis and prognosis of AS. We detail its utility for studying all aspects of AS, including valve anatomy, flow quantification, left ventricular volumes, mass, remodeling, and function, tissue mapping, and 4-dimensional flow magnetic resonance imaging. We also discuss different clinical situations where CMR could be useful in AS, for example, in low-flow low-gradient AS to confirm the low-flow state and to understand the reason for the left ventricular dysfunction or when there is a suspicion of associated cardiac amyloidosis.

Contemporary use of balloon aortic valvuloplasty and evaluation of its success in different hemodynamic entities of severe aortic valve stenosis.

To evaluate outcome assessment of percutaneous balloon aortic valvuloplasty (BAV) in different flow and gradient patterns of severe aortic stenosis (AS). The mean pressure gradient reduction after BAV is an often-used surrogate parameter to evaluate procedural success. The definition of a successful BAV has not been evaluated in different subgroups of severe AS, which were introduced in the latest guidelines on the management of patients with valvular heart disease. In this observational study, consecutive patients from July 2009 to March 2018 undergoing BAV were divided into normal-flow high-gradient (NFHG), low-flow low-gradient (LFLG), and paradoxical low-flow low-gradient (pLFLG) AS. Baseline characteristics, hemodynamic, and clinical information were collected and compared. One-hundred-fifty-six patients were grouped into NFHG (n = 68, 43.5%), LFLG (n = 68, 43.5%), and pLFLG (n = 20, 12.8%) AS. Mean age of the study population was 81 years. Cardiogenic shock or refractory heart failure (46.8%) was the most common underlying reasons for BAV. Spearman correlation revealed that the mean pressure gradient reduction, determined by echocardiography, had a moderate correlation with the increase in the aortic valve area (AVA) in patients with NFHG AS (ρ: 0.529, p < .001) but showed no association in patients with LFLG (ρ: 0.017, p = .289) and pLFLG (ρ: 0.030, p = .889) AS. BAV as bridge to surgical or transcatheter aortic valve replacement was possible in 44.2% of patients, with no difference between groups (p = .070). The mean pressure gradient reduction might be an adequate surrogate parameter for BAV success in patients with NFHG AS but is not suitable for patients with other hemodynamic entities.

Augmented left ventricular dyssynchrony by low-dose dobutamine stress suggested excellent cardiac resynchronization responses in low-flow low-gradient aortic stenosis.

Augmented left ventricular dyssynchrony by low-dose dobutamine stress suggested excellent cardiac resynchronization responses in low-flow low-gradient aortic stenosis.