Project description:BackgroundPre- and post-procedural hemodynamic changes which could affect adverse outcomes in aortic stenosis (AS) patients who undergo transcatheter aortic valve replacement (TAVR) have not been well investigated. Four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) enables accurate analysis of blood flow dynamics such as flow velocity, flow pattern, wall shear stress (WSS), and energy loss (EL). We sought to examine the changes in blood flow dynamics of patients with severe AS who underwent TAVR.MethodsWe examined 32 consecutive severe AS patients who underwent TAVR between May 2018 and June 2019 (17 men, 82 ± 5 years, median left ventricular ejection fraction 61%, 6 self-expanding valve), after excluding those without CMR because of a contraindication or inadequate imaging from the analyses. We analyzed blood flow patterns, WSS and EL in the ascending aorta (AAo), and those changes before and after TAVR using 4D flow CMR.ResultsAfter TAVR, semi-quantified helical flow in the AAo was significantly decreased (1.4 ± 0.6 vs. 1.9 ± 0.8, P = 0.002), whereas vortical flow and eccentricity showed no significant changes. WSS along the ascending aortic circumference was significantly decreased in the left (P = 0.038) and left anterior (P = 0.033) wall at the basal level, right posterior (P = 0.011) and left (P = 0.010) wall at the middle level, and right (P = 0.012), left posterior (P = 0.019) and left anterior (P = 0.028) wall at the upper level. EL in the AAo was significantly decreased (15.6 [10.8-25.1 vs. 25.8 [18.6-36.2]] mW, P = 0.012). Furthermore, a significant negative correlation was observed between EL and effective orifice area index after TAVR (r = - 0.38, P = 0.034).ConclusionsIn severe AS patients undergoing TAVR, 4D flow CMR demonstrates that TAVR improves blood flow dynamics, especially when a larger effective orifice area index is obtained.
Project description:Coronary flow reserve in patients with severe aortic stenosis decreases even in the absence of coronary stenosis. In this case, the dynamic changes in the coronary flow pattern around transcatheter aortic valve replacement were observed by periprocedural transesophageal echocardiography. (Level of Difficulty: Intermediate.).
Project description:BackgroundImpaired coronary flow reserve (CFR) portends a poor prognosis in patients with aortic stenosis. The present study aims to investigate how CFR changes over one year after transcatheter aortic valve implantation (TAVI) in patients with severe aortic stenosis, and to explore factors related to the changes.MethodsConsecutive patients undergoing TAVI were registered. CFR in the left anterior descending artery was measured by transthoracic echocardiography on three occasions pre-TAVI, one-day post-TAVI, and one-year post-TAVI.ResultsA total of 59 patients were enrolled, 46 of whom completed one-year follow-up. CFR was impaired in 35 (59.3%) patients pre-TAVI, but the impairment was only seen in 2 patients (4%) one-year post-TAVI. CFR value improved from 1.75 (1.50-2.10) cm/s pre-TAVI, to 2.00 (1.70-2.30) one-day post-TAVI, and further to 2.60 (2.30-3.10) one-year post-TAVI (P < 0.001). The median difference in CFR between pre-TAVI and one-year post-TAVI was 0.90 (0.53-1.20). Patients with significant improvement of CFR (more than the median value of 0.9) had larger aortic valve area (1.55 [1.38-1.92] vs. 1.36 cm2 [1.26-1.69], P = 0.042) and greater improvement in left ventricular ejection fraction (3.10 [-1.67-4.24] vs. -1.46 [-3.42-1.48] percentage points, P = 0.019) than those without.ConclusionsCFR is impaired in a considerable proportion of patients with severe aortic stenosis, but improvement is seen immediately after TAVI, and one year later. Patients with significant improvement of CFR had larger aortic valve area and greater increase in left ventricular ejection fraction after TAVI.
Project description:BackgroundA certain proportion of patients with severe aortic stenosis (AS) present with discordant grading between different diagnostic modalities, which raises uncertainty about the true severity of AS. The aim of this study was to compare the aortic valve area (AVA) measured on CT and echocardiography and demonstrate the factors affecting AVA discrepancies.MethodsBetween June 2011 and March 2016, 535 consecutive patients (66.83±8.80 years, 297 men) with AS who underwent pre-operative cardiac CT and echocardiography for aortic valve replacement were retrospectively included. AVA was obtained by AVA on echocardiography (AVAecho) and CT (AVACT) using a measurement of the left ventricular outflow tract on each modality and correlations between those measures were evaluated. Logistic regression analysis was performed to identify factors affecting the discordance for grading severe AS.ResultsThe AVACT and AVAecho showed a high correlation (r: 0.79, P <0.001) but AVACT was larger than the AVAecho (difference 0.26 cm2, P <0.001). By using the cut-off values of AVACT (<1.2 cm2) and AVAecho (<1.0 cm2) for diagnosing severe AS, the BSA (odds ratio [OR]: 68.03, 95% confidence interval [CI]: 5.45-849.99; P = 0.001), AVAecho (OR: 1.19, 95%CI: 1.14-1.24; P <0.001), tricuspid valve morphology (OR: 2.83, 95%CI: 1.23-6.50; P = 0.01), and normalized annulus area (OR: 1.02; 95%CI:1.02-1.03; P <0.001) were significant factors associated with the discordance between the AVAecho and AVACT.ConclusionPatients with larger BSA, AVAecho, and annulus, and tricuspid valve morphology were associated with the AVA discordance between the echocardiography and CT. Complementary use of CT with echocardiography for grading severe AS could be helpful in such conditions.
Project description:BackgroundTranscatheter aortic valve implantation (TAVI) is a minimally invasive, life-saving treatment for patients with severe aortic valve stenosis that improves quality of life. We examined cardiac output and cerebral blood flow in patients undergoing TAVI to test the hypothesis that improved cardiac output after TAVI is associated with an increase in cerebral blood flow.DesignProspective cohort study.SettingEuropean high-volume tertiary multidisciplinary cardiac care.ParticipantsThirty-one patients (78.3 ± 4.6 years; 61% female) with severe symptomatic aortic valve stenosis.MeasurementsNoninvasive prospective assessment of cardiac output (L/min) by inert gas rebreathing and cerebral blood flow of the total gray matter (mL/100 g per min) using arterial spin labeling magnetic resonance imaging in resting state less than 24 hours before TAVI and at 3-month follow-up. Cerebral blood flow change was defined as the difference relative to baseline.ResultsOn average, cardiac output in patients with severe aortic valve stenosis increased from 4.0 ± 1.1 to 5.4 ± 2.4 L/min after TAVI (P = .003). The increase in cerebral blood flow after TAVI strongly varied between patients (7% ± 24%; P = .41) and related to the increase in cardiac output, with an 8.2% (standard error = 2.3%; P = .003) increase in cerebral blood flow per every additional liter of cardiac output following the TAVI procedure.ConclusionFollowing TAVI, there was an association of increase in cardiac output with increase in cerebral blood flow. These findings encourage future larger studies to determine the influence of TAVI on cerebral blood flow and cognitive function.
Project description:AimsSex-specific thresholds of aortic valve calcification (AVC) have been proposed and validated in Caucasians. Thus, we aimed to validate their accuracy in Asians.Methods and resultsPatients with calcific aortic stenosis (AS) from seven international centres were included. Exclusion criteria were ≥moderate aortic/mitral regurgitation and bicuspid valve. Optimal AVC and AVC-density sex-specific thresholds for severe AS were obtained in concordant grading and normal flow patients (CG/NF). We included 1263 patients [728 (57%) Asians, 573 (45%) women, 837 (66%) with CG/NF]. Mean gradient was 48 (26-64) mmHg and peak aortic velocity 4.5 (3.4-5.1) m/s. Optimal AVC thresholds were: 2145 Agatston Units (AU) in men and 1301 AU in women for Asians; and 1885 AU in men and 1129 AU in women for Caucasians. Overall, accuracy (% correctly classified) was high and comparable either using optimal or guidelines' thresholds (2000 AU in men, 1200 AU in women). However, accuracy was lower in Asian women vs. Caucasian women (76-78% vs. 94-95%; P < 0.001). Accuracy of AVC-density (476 AU/cm2 in men and 292 AU/cm2 in women) was comparable to absolute AVC in Caucasians (91% vs. 91%, respectively, P = 0.74), but higher than absolute AVC in Asians (87% vs. 81%, P < 0.001). There was no interaction between AVC/AVC-density and ethnicity (all P > 0.41) with regards to AS haemodynamic severity.ConclusionAVC thresholds defining severe AS are comparable in Asian and Caucasian populations, and similar to those proposed in the guidelines. However, accuracy of AVC to identify severe AS in Asians (especially women) is sub-optimal. Therefore, the use of AVC-density is preferable in Asians.
Project description:The aim of the study presented here was to evaluate retinal and optic nerve head (ONH) perfusion in patients with severe asymptomatic carotid artery stenosis (CAS) compared with healthy controls and to analyze the impact of carotid endarterectomy using optical coherence tomography angiography (OCT-A). 25 eyes of 25 patients with CAS (study group) and 25 eyes of 25 healthy controls (control group) were prospectively included in this study. OCT-A was performed using RTVue XR Avanti (Optovue, Inc, Fremont, California, USA). The flow density data in the superficial and deep retinal OCT-angiogram of the macula and in the radial peripapillary capillary network (RPC) of the ONH were extracted and analyzed. The flow density in the superficial retinal OCT angiogram of the macula and in the ONH were significantly lower in the study group compared with the control group (macula: p?=?0.003) (ONH: p?=?0.013). The flow density in the ONH improved significantly after carotid endarterectomy (p?=?0.004). A reduced flow density was observed in patients with CAS when compared with healthy controls. The flow density also improved after carotid endarterectomy. Quantitative changes in the microvascular density, as measured using OCT-A, could well be useful in the diagnosis of CAS and the evaluation of therapy success.
Project description:PurposeLow-flow status is a mortality predictor in severe aortic stenosis (SAS) patients, including after transcatheter aortic valve implantation (TAVI) treatment. However, the best parameter to assess flow is unknown. Recent studies suggest that transaortic flow rate (FR) is superior to currently used stroke volume index (SVi) in defining low-flow states. Therefore, we aimed to evaluate the prognostic value of FR and SVi in patients undergoing TAVI.MethodsA single-centre retrospective analysis of all consecutive patients treated with TAVI for SAS between 2011 and 2019 was conducted. Low-FR was defined as < 200 mL/s and low-SVi as < 35 mL/m2. Primary endpoint was all-cause five-year mortality, analyzed using Kaplan-Meier curves and Cox regression models. Secondary endpoint was variation of NYHA functional class six months after procedure. Patients were further stratified according to ejection fraction (EF < 50%).ResultsOf 489 cases, 59.5% were low-FR, and 43.1% low-SVi. Low-flow patients had superior surgical risk, worse renal function, and had a higher prevalence of coronary artery disease. Low-FR was associated with mortality (hazard ratio 1.36, p = 0.041), but not after adjustment to EuroSCORE II. Normal-SVi was not associated with survival, despite a significative p-trend for its continuous value. No associations were found for flow-status and NYHA recovery. When stratifying according to preserved and reduced EF, both FR and SVi did not predict all-cause mortality.ConclusionIn patients with SAS undergoing TAVI, a low-FR state was associated with higher mortality, as well as SVi, but not at a 35 mL/m2 cut off.
Project description:AimsIn patients with aortic stenosis (AS), the coronary flow reserve decreases even in the absence of epicardial coronary artery stenosis. Systolic coronary flow reversal (SFR) reflecting reduced coronary microcirculation, often seen in patients with severe AS, has a potential negative impact on the pathogenesis of cardiac dysfunction. However, there are limited data on the relationship between the severity of AS and SFR, as well as on the benefits of transcatheter aortic valve implantation (TAVI). The aim of this study was to evaluate the relationship between the severity of AS and efficacy of TAVI in improving SFR.Methods and resultsConsecutive patients with AS who had undergone TAVI using transoesophageal echocardiography (TEE) from November 2020 to February 2022 were prospectively enrolled. Coronary flow in the left anterior descending artery as well as the aortic valve peak velocities, and the mean aortic valve pressure gradients (AVPGs), indicating the severity of AS, were measured using intraprocedural TEE before and after TAVI. The following parameters were measured as coronary flow: systolic and diastolic peak velocity (cm/s) and systolic and diastolic velocity-time integral (VTI) (cm). SFR was defined as the presence of a reversal coronary flow component in systole. The enrolled patients were classified into two groups according to the presence or absence of SFR before TAVI. A total of 25 patients were included: 13 had SFR and 12 who had no SFR, before TAVI. Patients with SFR had significantly higher aortic valve peak velocities (451.1 ± 45.9 vs. 372.1 ± 52.1 cm/s; P < 0.001) and mean AVPGs (49.2 ± 14.5 vs. 30.3 ± 11.6 mmHg; P = 0.002) than those without. The optimal binary cut-off aortic valve peak velocity values and the mean AVPG associated with the presence of SFR before TAVI were >410.0 cm/s (specificity, 75.0%; sensitivity, 92.3%) and >37.4 mmHg (specificity, 83.3%; sensitivity, 92.3%), respectively. After TAVI, SFR immediately disappeared in 11 of 13 patients with SFR (84.6%). Overall, the systolic coronary VTI significantly increased after TAVI (2.0 ± 4.7 vs. 6.4 ± 3.2 cm, P < 0.001), and this increase was greater in patients with SFR than in those without SFR before TAVI (interaction P = 0.035).ConclusionsSFR was found to be associated with the severity of AS and with a greater increase in systolic coronary flow immediately after TAVI.