Impact of Vascular Hemodynamics on Aortic Stenosis Evaluation: New Insights Into the Pathophysiology of Normal Flow-Small Aortic Valve Area-Low Gradient Pattern

Do flow-gradient groups determined by MDCT predict outcomes: validating CT stroke volume

BACKGROUND

Identifying severe aortic stenosis can be difficult especially among patients with low-flow states compared to normal flow. Non-invasive modalities can aid in the diagnosis for timely treatment.

METHODS

In this retrospective, single-center study of patients with aortic stenosis who underwent transcatheter aortic valve replacement (TAVR), we calculated stroke volume using CT blood pool based (CT-blp) analysis, echocardiogram and right heart catheterization (cath) performed before TAVR. We compared the performance of each modality in predicting 30-day and 1-year outcomes.

RESULTS

Three-hundred and forty-five patients were included with a median age of 84 (79-88) years and 52.8% females. CT-blp correlated more strongly (r = 0.60) with cath-derived stroke volume than echo (r = 0.37). After stratifying patients into groups based on flow and gradient using echo or CT-blp, there was no difference in mortality with either modality among the groups. However, the composite of mortality and hospital readmission was significantly higher in the low-flow low-gradient group (CT-blp 30-day OR 2.6, 95% CI 1.3-5.3, p < 0.01; 1-year OR 1.9, 95% CI 1.0-3.6; p = 0.04) compared to patients with normal flow high gradients when grouping was performed with CT-blp or echo.

CONCLUSION

Using the CT performed on patients pre-TAVR, CT-blp can provide an estimation of stroke volume that correlates well with invasive evaluation. The stroke volume may be used to stratify patient populations being evaluated for TAVR into flow gradient groups when echo is limited and avoid invasive catheterization to help identify patients with low-flow, low-gradient aortic stenosis. Further studies with larger cohorts are required to confirm our findings.

Impact of valvulo-vascular haemodynamics on left ventricular remodelling and the prevalence of discordant moderate aortic stenosis

AIMS

This study aims to describe the prevalence of discordant mild/moderate aortic stenosis (AS) in a population-based study and to identify the mechanisms that lead to reduced stroke volume (SV) and discordant moderate AS.

METHODS AND RESULTS

Discordant high-gradient (HG)-mild AS, defined as AVA > 1.5 cm2 and mean pressure gradient (MG) of 20-40 mmHg, and discordant low-gradient (LG) moderate AS, defined as AVA 1.0-1.5 cm2 and MG < 20 mmHg, were assessed in 883 individuals from the DANCAVAS screening study with aortic valve calcification and 257 individuals form the PROGRESSA study excluding those with left ventricular (LV) ejection fraction < 50%. In the DANCAVAS cohort, 150 men had mild/moderate AS of which 34% had discordance between MG and AVA, representing 66% with moderate AS. Among 262 patients in the combined cohort, 39% had discordant LG-moderate AS and 6% discordant HG-mild AS. Compared with concordant mild and moderate AS, individuals with discordant LG-moderate AS were more likely to present with LV concentric remodelling geometry (26 vs. 33 vs. 45%, P < 0.001), increased valvulo-arterial impedance (3.3 ± 0.7 vs. 3.6 ± 0.5 vs. 4.1 ± 0.7 mmHg/mL/m2, P < 0.001), and reduced systemic arterial compliance (SAC) (0.74 ± 0.22 vs. 0.81 ± 0.22 vs. 0.64 ± 0.18 mL/m2/mmHg, P < 0.001). Factors associated with SV index were relative wall thickness, LV end-diastolic diameter index, SAC, and LV remodelling pattern.

CONCLUSION

Discordant moderate AS is common, accounting for two-thirds of patients with moderate AS in the general male population. Patients with discordant LG-moderate AS have predominantly a concentric remodelling pattern with reduced SV. Reduced SV index was associated with signs of reduced vascular compliance, suggesting that altered vascular properties drive differences in remodelling patterns and discordant moderate AS.

Dobutamine Stress Echocardiography in Low-Gradient Aortic Stenosis

IMPORTANCE

Guidelines recommend the use of dobutamine stress echocardiography (DSE) in patients with low-gradient aortic stenosis (AS) and left ventricular ejection fraction (LVEF) <50%. However, a paucity of DSE data exists when LVEF >35%.

OBJECTIVE

To examine the diagnostic accuracy of DSE in patients with low-gradient AS with a wide range of LVEF and to examine the interaction between the diagnostic accuracy of DSE and LVEF.

DESIGN, SETTING, AND PARTICIPANTS

Patients with mean gradient <40 mm Hg, aortic valve area <1.0 cm2, and stroke volume index ≤35 mL/m2 undergoing DSE and cardiac computer tomography (C-CT) were identified from 3 prospectively collected patient cohorts and stratified according to LVEF: LVEF<35%, LVEF 35% to 50%, and LVEF>50%.

EXPOSURE

Dobutamine stress echocardiography and C-CT were performed on patients with low-gradient AS.

MAIN OUTCOMES AND MEASURES

Severe AS was defined as aortic valve calcification score ≥2,000 arbitrary units (AU) among men and ≥1,200 AU for women on C-CT.

RESULTS

Of 221 patients included in the study, 78 (35%) presented with LVEF <35%, 67 (30%) with LVEF 35% to 50%, and 76 (34%) with LVEF >50%. Mean-gradient and aortic valve peak velocity during DSE showed significant diagnostic heterogeneity between LVEF groups, being most precise when LVEF <35% (both areas under the curve [AUC] = 0.90), albeit with optimal thresholds of 30 mm Hg and 377 cm/sec and a limited diagnostic yield in patients with LVEF ≥35% (AUC = 0.67 and 0.66 in LVEF 35% to 50% and AUC = 0.65 and 0.60 in LVEF ≥50%). Using guideline thresholds led to a sensitivity/specificity of 49%/84% for all patients with LVEF <50%.

CONCLUSION AND RELEVANCE

While DSE is safe and leads to an increase in stroke volume in patients with low-gradient AS regardless of LVEF, the association between DSE gradients and AS severity assessed by C-CT demonstrates important heterogeneity depending on LVEF, with the highest accuracy in patients with LVEF <35%.

Sex Differences in Aortic Stenosis: From the Pathophysiology to the Intervention, Current Challenges, and Future Perspectives

Calcific aortic stenosis (AS) is a major cause of morbidity and mortality in high-income countries. AS presents sex-specific features impacting pathophysiology, outcomes, and management strategies. In women, AS often manifests with a high valvular fibrotic burden, small valvular annuli, concentric left ventricular (LV) remodeling/hypertrophy, and, frequently, supernormal LV ejection fraction coupled with diastolic dysfunction. Paradoxical low-flow low-gradient AS epitomizes these traits, posing significant challenges post-aortic valve replacement due to limited positive remodeling and significant risk of patient-prosthesis mismatch. Conversely, men present more commonly with LV dilatation and dysfunction, indicating the phenotype of classical low-flow low-gradient AS, i.e., with decreased LV ejection fraction. However, these distinctions have not been fully incorporated into guidelines for AS management. The only treatment for AS is aortic valve replacement; women are frequently referred late, leading to increased heart damage caused by AS. Therefore, it is important to reassess surgical planning and timing to minimize irreversible cardiac damage in women. The integrity and the consideration of sex differences in the management of AS is critical. Further research, including sufficient representation of women, is needed to investigate these differences and to develop individualized, sex-specific management strategies.

The Impact of Left Ventricular Performance and Afterload on the Evaluation of Aortic Valve Stenosis: A 1D Mathematical Modeling Approach

The transaortic valvular pressure gradient (TPG) plays a central role in decision-making for patients suffering from severe aortic stenosis. However, the flow-dependence nature of the TPG makes the diagnosis of aortic stenosis challenging since the markers of cardiac performance and afterload present high physiological interdependence and thus, isolated effects cannot be measured directly in vivo. We used a validated 1D mathematical model of the cardiovascular system, coupled with a model of aortic stenosis, to assess and quantify the independent effect of the main left ventricular performance parameters (end-systolic (Ees) and end-diastolic (Eed) elastance) and principal afterload indices (total vascular resistance (TVR) and total arterial compliance (TAC)) on the TPG for different levels of aortic stenosis. In patients with critical aortic stenosis (aortic valve area (AVA) ≤ 0.6 cm2), a 10% increase of Eed from the baseline value was associated with the most important effect on the TPG (-5.6 ± 0.5 mmHg, p < 0.001), followed by a similar increase of Ees (3.4 ± 0.1 mmHg, p < 0.001), in TAC (1.3 ±0.2 mmHg, p < 0.001) and TVR (-0.7 ± 0.04 mmHg, p < 0.001). The interdependence of the TPG left ventricular performance and afterload indices become stronger with increased aortic stenosis severity. Disregarding their effects may lead to an underestimation of stenosis severity and a potential delay in therapeutic intervention. Therefore, a comprehensive evaluation of left ventricular function and afterload should be performed, especially in cases of diagnostic challenge, since it may offer the pathophysiological mechanism that explains the mismatch between aortic severity and the TPG.

Low-flow, Low-gradient Severe Aortic Stenosis: A Review

Aortic stenosis (AS) is a common valve pathology experienced by patients worldwide. There are limited population-based studies assessing its prevalence; however, epidemiological studies emphasize that the burden of disease is growing. Recognizing AS relies on accurate clinical assessment and diagnostic investigations. Patients who develop severe AS are often referred to the heart team for assessment of aortic valve intervention. Although echocardiography has traditionally been used to screen and monitor the progression of AS, there can be discordance between measurements in a low-flow state. Such patients may have truly severe AS and potentially derive long-term benefit from aortic valve intervention. Accurately identifying these patients with the use of ancillary testing has been the focus of research for several years. In this article, we discuss the contemporary approaches and challenges in identifying and managing patients with low-flow, low-gradient severe AS.

Arterial stiffness in aortic stenosis - complex clinical and prognostic implications

Arterial stiffness and degenerative aortic stenosis (AoS) are frequently associated leading to a combined valvular and vascular load imposed on the left ventricle (LV). Vascular load consists of a pulsatile load represented by arterial stiffness and a steady load corresponding to vascular resistance. Increased vascular load in AoS has been associated with LV dysfunction and poor prognosis in pre-intervention state, as well as after aortic valve replacement (AVR), suggesting that the evaluation of arterial load in AoS may have clinical benefits. Nevertheless, studies that investigated arterial stiffness in AoS either before or after AVR used various methods of measurement and their results are conflicting. The aim of the present review was to summarize the main pathophysiological mechanisms which may explain the complex valvulo-arterial interplay in AoS and their consequences on LV structure and function on the patients' outcome. Future larger studies are needed to clarify the complex hemodynamic modifications produced by increased vascular load in AoS and its changes after AVR. Prospective evaluation is needed to confirm the prognostic value of arterial stiffness in patients with AoS. Simple, non-invasive, reliable methods which must be validated in AoS still remain to be established before implementing arterial stiffness measurement in patients with AoS in clinical practice.

Arterial Wave Reflection and Aortic Valve Stenosis: Diagnostic Challenges and Prognostic Significance

Introduction

Arterial wave reflection is an important component of the left ventricular afterload, affecting both pressure and flow to the aorta. The aim of the present study was to evaluate the impact of wave reflection on transvalvular pressure gradients (TPG), a key parameter for the evaluation of aortic valve stenosis (AS), as well as its prognostic significance in patients with AS undergoing a transcatheter aortic valve replacement (TAVR).

Materials and Methods

The study population consisted of 351 patients with AS (mean age 84 ± 6 years, 43% males) who underwent a complete hemodynamic evaluation before the TAVR. The baseline assessment included right and left heart catheterization, transthoracic echocardiography, and a thorough evaluation of the left ventricular afterload by means of wave separation analysis. The cohort was divided into quartiles according to the transit time of the backward pressure wave (BWTT). Primary endpoint was all-cause mortality at 1 year.

Results

Early arrival of the backward pressure wave was related to lower cardiac output (Q1: 3.7 ± 0.9 lt/min vs Q4: 4.4 ± 1.0 lt/min, p &lt; 0.001) and higher aortic systolic blood pressure (Q1: 132 ± 26 mmHg vs Q4: 117 ± 26 mmHg, p &lt; 0.001). TPG was significantly related to the BWTT, patients in the arrival group exhibiting the lowest TPG (mean TPG, Q1: 37.6 ± 12.7 mmHg vs Q4: 44.8 ± 14.7 mmHg, p = 0.005) for the same aortic valve area (AVA) (Q1: 0.58 ± 0.35 cm2 vs 0.61 ± 0.22 cm2, p = 0.303). In multivariate analysis, BWTT remained an independent determinant of mean TPG (beta 0.3, p = 0.002). Moreover, the prevalence of low-flow, low-gradient AS with preserved ejection fraction was higher in patients with early arterial reflection arrival (Q1: 33.3% vs Q4: 14.9%, p = 0.033). Finally, patients with early arrival of the reflected wave (Q1) exhibited higher all-cause mortality at 1 year after the TAVR (unadjusted HR: 2.33, 95% CI: 1.17–4.65, p = 0.016).

Conclusion

Early reflected wave arrival to the aortic root is associated with poor prognosis and significant aortic hemodynamic alterations in patients undergoing a TAVR for AS. This is related to a significant decrease in TPG for a given AVA, leading to a possible underestimation of the AS severity.

Comparison of Simultaneous Transthoracic Versus Transesophageal Echocardiography for Assessment of Aortic Stenosis

Transthoracic echocardiography (TTE) is the gold standard for aortic stenosis (AS) assessment. Transesophageal echocardiography (TEE) provides better resolution, but its effect on AS assessment is unclear. To answer this question, we studied 56 patients with ≥moderate AS. Initial TTE (TTE1) was followed by conscious sedation with simultaneous TEE and TTE2. Based on conservative versus actionable implication, AS types were dichotomized into group A, comprising moderate and normal-flow low-gradient, and group B, comprising high gradient, low ejection fraction low-flow low-gradient, and paradoxical low-flow low-gradient AS. Paired analysis of echocardiographic variables and AS types measured by TEE versus TTE2 and by TEE versus TTE1 was performed. TEE versus simultaneous TTE2 comparison demonstrated higher mean gradients (31.7 ± 10.5 vs 27.4 ± 10.5 mm Hg) and velocities (359 ± 60.6 vs 332 ± 63.1 cm/s) with TEE, but lower left ventricular outflow velocity-time-integral (VTI₁) (18.6 ± 5.1 vs 20.2 ± 6.1 cm), all p <0.001. This resulted in a lower aortic valve area (0.8 ± 0.21 vs 0.87 ± 0.28 cm²), p <0.001, and a net relative risk of 1.86 of group A to B upgrade. TEE versus (awake state) TTE1 comparison revealed a larger decrease in VTI₁ because of a higher initial awake state VTI₁ (22 ± 5.6 cm), resulting in similar Doppler-velocity-index and aortic valve area decrease with TEE, despite a slight increase in mean gradients of 0.8 mm Hg (confidence interval -1.44 to 3.04) and velocities of 10 cm/s (confidence interval -1.5 to 23.4). This translated into a net relative risk of 1.92 of group A to B upgrade versus TTE1. In conclusion, TEE under conscious sedation overestimates AS severity compared with both awake state TTE and simultaneous sedation state TTE, accounted for by different Doppler insonation angles obtained in transapical versus transgastric position.

Association between serum cystatin C level and hemodynamically significant aortic stenosis: a prospective cohort study

BACKGROUND

Cystatin C (CysC) is a cysteine protease inhibitor involved in proteins catabolism and plays an essential role in human vascular pathophysiology. CysC may also increase the risk of aortic stenosis (AS), but limited studies have reported on this association. This study aimed to investigate if elevated serum CysC levels are associated with hemodynamically significant AS.

METHODS

Serum CysC levels were estimated in 4,791 participants, samples were collected in 1990-1992. The study population was divided into quintile groups. Follow-up continued in 2011-2013 when participants returned for echocardiography examination. Incidence of aortic valve disease (AVD) was ascertained by Doppler echocardiography through the end of 2013. AVD defined in hemodynamic progression was assessed and classified as aortic sclerosis, mild stenosis, and moderate-to-severe stenosis.

RESULTS

Overall, a total of 4,791 participants (mean age: 54.8 ± 5.0 years, females: 57.6%, blacks: 8.2%) were included in this study. During a follow-up of 21 years, we identified 736 cases (15.4%) of aortic sclerosis, 194 cases (4.0%) of mild stenosis, and 42 cases (0.7%) of moderate-to-severe stenosis. Compared with serum CysC levels within individual quintile groups, the odds ratio (OR) was per standard deviation associated with an increased incidence of AVD (OR = 1.15, 95% CI: 1.05-1.26,P = 0.002).

CONCLUSIONS

In this large population-based study, an increased serum CysC levels is independently associated with the incidence of hemodynamically significant AS. However, this association appears not to extend to patients with extremely high serum CysC levels and necessitate further investigation.

Diagnosis and Management of Aortic Valve Stenosis: The Role of Non-Invasive Imaging

Aortic stenosis is the most common heart valve disease necessitating surgical or percutaneous intervention. Imaging has a central role for the initial diagnostic work-up, the follow-up and the selection of the optimal timing and type of intervention. Referral for aortic valve replacement is currently driven by the severity and by the presence of aortic stenosis-related symptoms or signs of left ventricular systolic dysfunction. This review aims to provide an update of the imaging techniques and seeks to highlight a practical approach to help clinical decision making.

Arterial biomarkers in the evaluation, management and prognosis of aortic stenosis

Degenerative aortic valve stenosis is the most common primary valve disease and a significant cause of cardiovascular morbidity and mortality. In an era when new techniques for the management of aortic stenosis are gaining ground, the understanding of this disease is more important than ever to optimize treatment. So far, the focus has been placed on the assessment of the valve itself. However, the role that the arterial system plays in the pathogenesis and natural history of the disease needs to be further elucidated. Arteriosclerosis, when it coexists with a stenotic valve, augments the load posed on the left ventricle contributing to greater impairment of cardiovascular function. Arterial stiffness, a well-established predictor for cardiovascular disease and all-cause mortality, could play a role in the prognosis and quality of life of this population. Several studies using a variety of indices to assess arterial stiffness have tried to address the potential utility of arterial function assessment in the case of aortic stenosis. Importantly, reliable data identify a prognostic role of arterial biomarkers in aortic stenosis and stress their possible use to optimize timing and method of treatment. This review aims at summarizing the existing knowledge on the interplay between the heart and the vessels in the presence of degenerative aortic stenosis, prior, upon and after interventional management. Further, it discusses the evidence supporting the potential clinical application of arterial biomarkers for the assessment of progression, severity, management and prognosis of aortic stenosis.

Personalized intervention cardiology with transcatheter aortic valve replacement made possible with a non-invasive monitoring and diagnostic framework

One of the most common acute and chronic cardiovascular disease conditions is aortic stenosis, a disease in which the aortic valve is damaged and can no longer function properly. Moreover, aortic stenosis commonly exists in combination with other conditions causing so many patients suffer from the most general and fundamentally challenging condition: complex valvular, ventricular and vascular disease (C3VD). Transcatheter aortic valve replacement (TAVR) is a new less invasive intervention and is a growing alternative for patients with aortic stenosis. Although blood flow quantification is critical for accurate and early diagnosis of C3VD in both pre and post-TAVR, proper diagnostic methods are still lacking because the fluid-dynamics methods that can be used as engines of new diagnostic tools are not well developed yet. Despite remarkable advances in medical imaging, imaging on its own is not enough to quantify the blood flow effectively. Moreover, understanding of C3VD in both pre and post-TAVR and its progression has been hindered by the absence of a proper non-invasive tool for the assessment of the cardiovascular function. To enable the development of new non-invasive diagnostic methods, we developed an innovative image-based patient-specific computational fluid dynamics framework for patients with C3VD who undergo TAVR to quantify metrics of: (1) global circulatory function; (2) global cardiac function as well as (3) local cardiac fluid dynamics. This framework is based on an innovative non-invasive Doppler-based patient-specific lumped-parameter algorithm and a 3-D strongly-coupled fluid-solid interaction. We validated the framework against clinical cardiac catheterization and Doppler echocardiographic measurements and demonstrated its diagnostic utility by providing novel analyses and interpretations of clinical data in eleven C3VD patients in pre and post-TAVR status. Our findings position this framework as a promising new non-invasive diagnostic tool that can provide blood flow metrics while posing no risk to the patient. The diagnostic information, that the framework can provide, is vitally needed to improve clinical outcomes, to assess patient risk and to plan treatment.

Evaluation and Management of Aortic Stenosis in Chronic Kidney Disease: A Scientific Statement From the American Heart Association

Aortic stenosis with concomitant chronic kidney disease (CKD) represents a clinical challenge. Aortic stenosis is more prevalent and progresses more rapidly and unpredictably in CKD, and the presence of CKD is associated with worse short-term and long-term outcomes after aortic valve replacement. Because patients with advanced CKD and end-stage kidney disease have been excluded from randomized trials, clinicians need to make complex management decisions in this population that are based on retrospective and observational evidence. This statement summarizes the epidemiological and pathophysiological characteristics of aortic stenosis in the context of CKD, evaluates the nuances and prognostic information provided by noninvasive cardiovascular imaging with echocardiography and advanced imaging techniques, and outlines the special risks in this population. Furthermore, this statement provides a critical review of the existing literature pertaining to clinical outcomes of surgical versus transcatheter aortic valve replacement in this high-risk population to help guide clinical decision making in the choice of aortic valve replacement and specific prosthesis. Finally, this statement provides an approach to the perioperative management of these patients, with special attention to a multidisciplinary heart-kidney collaborative team-based approach.

Multimodality Imaging for Discordant Low-Gradient Aortic Stenosis: Assessing the Valve and the Myocardium

Aortic stenosis (AS) is a disease of the valve and the myocardium. A correct assessment of the valve disease severity is key to define the need for aortic valve replacement (AVR), but a better understanding of the myocardial consequences of the increased afterload is paramount to optimize the timing of the intervention. Transthoracic echocardiography remains the cornerstone of AS assessment, as it is universally available, and it allows a comprehensive structural and hemodynamic evaluation of both the aortic valve and the rest of the heart. However, it may not be sufficient as a significant proportion of patients with severe AS presents with discordant grading (i.e., an AVA ≤ 1 cm² and a mean gradient <40 mmHg) which raises uncertainty about the true severity of AS and the need for AVR. Several imaging modalities (transesophageal or stress echocardiography, computed tomography, cardiovascular magnetic resonance, positron emission tomography) exist that allow a detailed assessment of the stenotic aortic valve and the myocardial remodeling response. This review aims to provide an updated overview of these multimodality imaging techniques and seeks to highlight a practical approach to help clinical decision making in the challenging group of patients with discordant low-gradient AS.

The impact of aortic valve replacement on survival in patients with normal flow low gradient severe aortic stenosis: a propensity-matched comparison

Aims

To assess the survival benefit of aortic valve replacement (AVR) in patients with normal flow low gradient severe aortic stenosis (AS).

Methods and results

A retrospective study of prospectively collected data of 276 patients (mean age 75 ± 15 years, 51% male) with normal transaortic flow [flow rate (FR) ≥200 mL/s or stroke volume index (SVi) ≥35 mL/m2] and severe AS (aortic valve area <1.0 cm2). The outcome measure was all-cause mortality. Of the 276 patients, 151 (55%) were medically treated, while 125 (45%) underwent an AVR. Over a mean follow-up of 3.2 ± 1.8 years (range 0–6.9 years), a total of 96 (34.8%) deaths occurred: 17 (13.6%) in AVR group vs. 79 (52.3%) in those medically treated, when transaortic flow was defined by FR (P < 0.001). When transaortic flow was defined by SVi, a total of 79 (31.3%) deaths occurred: 18 (15.1%) in AVR group vs. 61 (45.9%) in medically treated (P < 0.001). In a propensity-matched multivariable Cox regression analysis adjusting for age, gender, body surface area, smoking, hypertension, diabetes mellitus, atrial fibrillation, peripheral vascular disease, chronic kidney disease, left ventricular ejection fraction, left ventricular mass, and mean aortic gradient, not having AVR was associated with a 6.3-fold higher hazard ratio (HR) of all-cause mortality [HR 6.28, 95% confidence interval (CI) 3.34–13.16; P < 0.001] when flow was defined by FR. In the SVi-guided model, it was 3.83-fold (HR 3.83, 95% CI 2.30–6.37; P < 0.001).

Conclusion

In patients with normal flow low gradient severe AS, AVR was associated with a significantly improved survival compared with those who received standard medical treatment.

Echocardiographic Assessment of Aortic Stenosis under Sedation Underestimates Stenosis Severity

BACKGROUND

Sedation can impact aortic stenosis (AS) classification, which depends on left ventricular ejection fraction (<≥ [less than or greater than and/or equal to] 50%), aortic valve area (AVA<≥ 1 cm²), mean pressure gradient (<≥ 40 mm Hg), peak velocity <≥ 400 cm/sec, and stroke volume index (SVI <≥35 mL/m²). We compared AS classification by transthoracic echo (TTE) during wakefulness versus sedation.

METHODS

Immediately following a baseline TTE performed during wakefulness, another TTE was done during sedation delivered for a concomitant transesophageal study in 69 consecutive patients with AS (mean age 78 ± 7 years, 32 males). AVA was calculated through the continuity equation using the relevant hemodynamic parameters measured by each TTE study and same left ventricular outflow tract. AS class was defined as moderate, severe high gradient (HG), low ejection fraction low flow low gradient (LF-LG), paradoxical LF-LG (PLFLG), and normal flow low gradient (NF-LG). Based on conservative versus invasive treatment implication, AS classes were aggregated into group A (moderate AS and NFLG) and group B (HG, low-EF LF-LG, and PLFLG).

RESULTS

During sedation, systolic and diastolic blood pressure decreased by 14.3 ± 29 and 8 ± 22 mm Hg, respectively, mean pressure gradient from 30.4 ± 10.9 to 27.2 ± 10.8 mm Hg, peak velocity from 345.3 ± 57.7 to 329.3 ± 64.8 cm/m², and SVI from 41.5 ± 11.3 to 38.3 ± 11.8 mL/m² (all P < .05). Calculated AVA was similar (delta = -0.009 ± 0.15 cm²). Individual discrepancies in hemodynamic parameters between the paired TTE studies resulted in an overall 17.4% rate of AS intergroup misclassification with sedation, with a relative risk of 1.09 of downgrade misclassification from group B to A versus upgrade misclassification (P < .001).

CONCLUSIONS

Sedation TTE assessment downgrades AS severity in a significant proportion of patients, with a conversely smaller proportion of patients being upgraded, and therefore cannot be a substitute for wakefulness assessment.

Aortic Stenosis, Aortic Regurgitation and Arterial Hypertension

BACKGROUND

Hypertension (HT) is an important risk factor for cardiovascular disease and might precipitate pathology of the aortic valve.

OBJECTIVE

To investigate the association of HT with aortic dysfunction (including both aortic regurgitation and stenosis) and the impact of antihypertensive treatment on the natural course of underlying aortic disease.

METHODS

We performed a systematic review of the literature for all relevant articles assessing the correlation between HT and phenotype of aortic disease.

RESULTS

Co-existence of HT with aortic stenosis and aortic regurgitation is highly prevalent in hypertensive patients and predicts a worse prognosis. Certain antihypertensive agents may improve haemodynamic parameters (aortic jet velocity, aortic regurgitation volume) and remodeling of the left ventricle, but there is no strong evidence of benefit regarding clinical outcomes. Renin-angiotensin system inhibitors, among other vasodilators, are well-tolerated in aortic stenosis.

CONCLUSION

Several lines of evidence support a detrimental association between HT and aortic valve disease. Therefore, HT should be promptly treated in aortic valvulopathy. Despite conventional wisdom, specific vasodilators can be used with caution in aortic stenosis.

Hypertension and transcatheter aortic valve replacement: parallel or series?

Aortic stenosis (AS) is the most common valvular heart disease in the elderly and it causes significant morbidity and mortality. Hypertension is also highly prevalent in elderly patients with AS, and AS patients with hypertension have worse outcomes. Accurate assessment of AS severity and understanding its relationship with arterial compliance has become increasingly important as the options for valve management, particularly transcatheter interventions, have grown. The parameters used for quantifying stenosis severity have traditionally mainly focused on the valve itself. However, AS is now recognized as a systemic disease involving aging ventricles and stiff arteries rather than one limited solely to the valve. Over the last decade, valvuloarterial impedance, a measure of global ventricular load, has contributed to our understanding of the pathophysiology and course of AS in heterogeneous patients, even when segregated by symptoms and severity. This review summarizes our growing understanding of the interplay between ventricle, valve, and vessel, with a particular emphasis on downstream vascular changes after transcatheter aortic valve replacement and the role of valvuloarterial impedance in predicting left ventricular changes and prognosis in patients with various transvalvular flow patterns.