Differences in blood flow dynamics between balloon- and self-expandable valves in patients with aortic stenosis undergoing transcatheter aortic valve replacement

BACKGROUND

The differences in pre- and early post-procedural blood flow dynamics between the two major types of bioprosthetic valves, the balloon-expandable valve (BEV) and self-expandable valve (SEV), in patients with aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR), have not been investigated. We aimed to investigate the differences in blood flow dynamics between the BEV and SEV using four-dimensional flow cardiovascular magnetic resonance (4D flow CMR).

METHODS

We prospectively examined 98 consecutive patients with severe AS who underwent TAVR between May 2018 and November 2021 (58 BEV and 40 SEV) after excluding those without CMR because of a contraindication, inadequate imaging from the analyses, or patients' refusal. CMR was performed in all participants before (median interval, 22 [interquartile range (IQR) 4-39] days) and after (median interval, 6 [IQR 3-6] days) TAVR. We compared the changes in blood flow patterns, wall shear stress (WSS), and energy loss (EL) in the ascending aorta (AAo) between the BEV and SEV using 4D flow CMR.

RESULTS

The absolute reductions in helical flow and flow eccentricity were significantly higher in the SEV group compared in the BEV group after TAVR (BEV: - 0.22 ± 0.86 vs. SEV: - 0.85 ± 0.80, P < 0.001 and BEV: - 0.11 ± 0.79 vs. SEV: - 0.50 ± 0.88, P = 0.037, respectively); there were no significant differences in vortical flow between the groups. The absolute reduction of average WSS was significantly higher in the SEV group compared to the BEV group after TAVR (BEV: - 0.6 [- 2.1 to 0.5] Pa vs. SEV: - 1.8 [- 3.5 to - 0.8] Pa, P = 0.006). The systolic EL in the AAo significantly decreased after TAVR in both the groups, while the absolute reduction was comparable between the groups.

CONCLUSIONS

Helical flow, flow eccentricity, and average WSS in the AAo were significantly decreased after SEV implantation compared to BEV implantation, providing functional insights for valve selection in patients with AS undergoing TAVR. Our findings offer valuable insights into blood flow dynamics, aiding in the selection of valves for patients with AS undergoing TAVR. Further larger-scale studies are warranted to confirm the prognostic significance of hemodynamic changes in these patients.

Association of coronary plaque morphology with inflammatory biomarkers and target lesion revascularization in patients with chronic coronary syndrome: an optical coherence tomography study

BACKGROUND

The characteristics of high-risk coronary atherosclerosis evaluated using optical coherence tomography (OCT) can have a prognostic role. Inflammatory biomarkers may be related to the severity of coronary artery disease. This study investigated the association of high-risk morphological features of coronary plaques on OCT with circulating levels of inflammatory biomarkers and target lesion revascularization (TLR).

MATERIALS AND METHODS

We prospectively analyzed the data of 30 consecutive patients with chronic coronary syndrome who underwent percutaneous coronary intervention (PCI) using OCT. The levels of interleukin-6, tumor necrosis factor-alpha, high-sensitivity C-reactive protein, pentraxin 3, vascular endothelial growth factor, and monocyte chemoattractant protein-1 (MCP-1) were measured in plasma samples. Coronary plaque characteristics were scored quantitatively in the form of coronary plaque risk score (CPRS). The estimated high-risk plaque characteristics for TLR were plaque rupture, plaque erosion, calcified nodule, lipid-rich plaque, thin-cap fibroatheroma, cholesterol crystals, macrophage infiltration, microchannels, calcification angle >90°, and microcalcifications. Each high-risk feature carries 1 point. Patients were defined as having a low CPRS (CPRS ≤3) or a high CPRS (CPRS ≥4).

RESULTS

The primary outcome was TLR. TLR occurred in 6 (20%) patients within 15 months of PCI. High CPRS on OCT was directly correlated with TLR (P=0.029). In logistic regression analysis, CPRS was associated with TLR (odds ratio, 10.0; 95% confidence interval, 1.34-74.5). Serum MCP-1 level was significantly correlated with the CPRS (P=0.020).

CONCLUSIONS

In patients with chronic coronary syndrome, CPRS may be a surrogate predictor of TLR. Serum MCP-1 may aid in the detection of high-risk coronary atherosclerosis.

Prognostic Value of Liver Fibrotic Markers in Patients With Heart Failure

Several liver fibrotic markers are associated with prognosis in patients with heart failure (HF). However, the optimal markers for outcome prediction remain unclear. This study aimed to simultaneously investigate the prognostic value of liver fibrotic markers and the associations between these markers and clinical parameters in patients with HF without organic liver disease. We prospectively examined 211 consecutive patients with chronic HF between April 2018 and August 2021, excluding those with organic liver disease, using liver magnetic resonance imaging and ultrasound. A total of 7 representative liver fibrotic markers were measured in all patients. The primary outcome of interest was the composite of all-cause death and hospitalization for worsening HF. During a median follow-up period of 747 (interquartile range 465 to 1,042) days, the primary outcome occurred in 45 patients. Patients with higher hyaluronic acid and type III procollagen N-terminal peptide (P-III-P) levels showed a significantly higher incidence of the primary outcome than those without (p <0.001 and p = 0.005, respectively). The multivariable Cox regression analysis revealed that hyaluronic acid and P-III-P levels were independently associated with the risk of adverse events (hazard ratio 1.84, 95% confidence interval 1.18 to 2.87 and hazard ratio 2.89, 95% confidence interval 1.32 to 6.34, respectively) even after adjustment for a mortality prediction model, whereas the other 5 markers were not associated with the primary outcome. In conclusion, among the representative liver fibrotic markers, hyaluronic acid and P-III-P might be the optimal markers for outcome prediction in patients with HF.

Impact of COVID-19 pandemic on emergency medical system and management strategies in patients with acute coronary syndrome

The global coronavirus disease-2019 (COVID-19) pandemic is associated with reduced rate of percutaneous coronary intervention (PCI). However, there were a few data showing how emergency medical system (EMS) and management strategies for acute coronary syndrome (ACS) changed during the pandemic. We sought to clarify changes on characteristics, treatments, and in-hospital mortality of patients with ACS transported via EMS between pre- and post-pandemic. We examined consecutive 656 patients with ACS admitted to Sapporo City ACS Network Hospitals between June 2018 and November 2021. The patients were divided into pre- and post-pandemic groups. The number of ACS hospitalizations declined significantly during the pandemic (proportional reduction 66%, coefficient -0.34, 95% CI -0.50 to -0.18, p < 0.001). The median time from an EMS call to hospital was significantly longer in post-pandemic group than in pre-pandemic group (32 [26-39] vs. 29 [25-36] min, p = 0.008). There were no significant differences in the proportion of patients with ACS receiving PCI, and in-hospital mortality between the groups. The COVID-19 pandemic had a significant impact on EMS and management in patients with ACS. Although a significant decline was observed in ACS hospitalizations, the proportion of patients with ACS receiving emergency PCI remained during the pandemic.

Impact of right ventricular reserve on exercise capacity and quality of life in patients with left ventricular assist device

Although measuring right ventricular (RV) function during exercise is more informative than assessing it at rest, the relationship between RV reserve function, exercise capacity, and health-related quality of life (HRQoL) in patients with left ventricular assist devices (LVAD) remains unresolved. We aimed to investigate whether RV reserve assessed by the change in RV stroke work index (RVSWI) during exercise is correlated with exercise capacity and HRQoL in patients with LVAD. We prospectively assessed 24 consecutive patients with LVAD who underwent invasive right heart catheterization in the supine position. Exercise capacity and HRQoL were assessed using the 6-min walk distance (6 MWD) and peak oxygen consumption (V̇o₂) in cardiopulmonary exercise testing, and the EuroQol visual analog scale (EQ-VAS), respectively. The patients were divided into two groups according to the median ΔRVSWI (change from rest to peak exercise). Patients with lower ΔRVSWI had significantly lower changes in cardiac index and absolute value of RV dP/dt than those with higher ΔRVSWI. The ΔRVSWI was positively correlated with 6 MWD (r = 0.59, P = 0.003) and peak V̇o₂ (r = 0.56, P = 0.006). In addition, ΔRVSWI was positively correlated with the EQ-VAS (r = 0.44, P = 0.030). In contrast, there was no significant correlation between RVSWI at rest and 6 MWD (r = -0.34, P = 0.88), peak V̇o₂ (r = 0.074, P = 0.74), or EQ-VAS (r = 0.127, P = 0.56). Our findings suggest that the assessment of RV reserve function is useful for risk stratification in patients with LVAD.NEW & NOTEWORTHY The change in right ventricular stroke work index (RVSWI) during exercise, not RVSWI at rest, was associated with exercise capacity and HRQoL. Our findings suggest that the assessment of change in RVSWI during exercise as a surrogate of RV reserve function may aid in risk stratification of patients with LVAD.

Prognostic Significance of Peak Workload-to-Weight Ratio by Cardiopulmonary Exercise Testing in Chronic Heart Failure

The prognostic impact of peak workload-to-weight ratio (PWR) during cardiopulmonary exercise testing (CPET) and its determinants in patients with chronic heart failure (CHF) are not well understood. Consecutive 514 patients with CHF referred for CPET at the Hokkaido University Hospital between 2013 and 2018 were identified. The primary outcome was a composite of hospitalization because of worsening heart failure and death. PWR was calculated as peak workload normalized to body weight (W/kg) by CPET. Patients with low PWR (cut-off median 1.38 [W/kg], n = 257) were older and more anemic than those with high PWR (n = 257). In CPET, patients with low PWR displayed reduced peak oxygen consumption and impaired ventilatory efficiency compared with those with high PWR, whereas the peak respiratory exchange ratio was not significantly different between the 2 groups. There were 89 patients with events over a median follow-up period of 3.3 (interquartile range 0.8 to 5.5) years. The incidence of composite events was significantly higher in patients with low PWR than in those with high PWR (log-rank p <0.0001). In the multivariable Cox regression, lower PWR was associated with adverse events (hazard ratio 0.31, 95% confidence interval 0.13 to 0.73, p = 0.008). Low hemoglobin concentration was strongly related to impaired PWR (β coefficient = 0.43, per 1 g/100 ml increased, p <0.0001). In conclusion, PWR was associated with worse clinical outcomes, where blood hemoglobin was strongly related to PWR. Further study is required to identify therapies targeting peak workload achievements in exercise stress tests to improve the outcome in patients with CHF.

Impact of right ventricular reserve on exercise capacity and quality of life in patients with left ventricular assist device

Background

Right heart failure following left ventricular assist device (LVAD) implantation is a major complication which significantly impairs functional capacity and quality of life (QoL). Right ventricular (RV) reserve function may limit exercise capacity and QoL in LVAD patients; however, most patients show normal RV haemodynamics at rest.

Purpose

The aim of this study was to investigate whether RV reserve assessed by the changes of RV function during exercise is correlated with exercise capacity and QoL in patients with LVAD.

Methods

We prospectively examined 20 consecutive LVAD patients who were admitted to our university hospital between June 2020 and November 2021 after excluding those who were unable to perform exercise (n=8). All patients underwent invasive exercise right heart catheterisation with simultaneous echocardiography in the supine position. RV stroke work index (RVSWI) was calculated as 0.0136 × stroke volume index × (mean pulmonary artery pressure [mPAP] − right atrial pressure [RAP]) at rest and during exercise. Exercise capacity and QoL were assessed by 6-minute walk distance (6MWD) and peak oxygen consumption (VO2) in cardiopulmonary exercise testing, and the EuroQol visual analogue scale (EQ-VAS), respectively. The patients were divided into two groups according to the median ΔRVSWI (RVSWI change from rest to peak exercise) of 1.45 (interquartile range [IQR] −0.31 to 8.25) g/m2.

Results

Patients were predominantly male (75%) and the median age was 47 (IQR 38–60) years. Patients with lower ΔRVSWI had significantly higher change on RAP (P=0.019), but significantly lower change on mPAP (P&lt;0.001) compared to those with higher ΔRVSWI. There were no significant differences in age, gender, primary aetiology of heart failure, type of LVAD devices, or echocardiographic parameters including tricuspid annular plane systolic excursion, and RVSWI at rest between the groups. ΔRVSWI during exercise were positively correlated with 6MWD (R=0.69, P&lt;0.01) and peak VO2 (R=0.66, P&lt;0.01) (Figure A). In addition, ΔRVSWI during exercise were positively correlated with the EQ-VAS (R=0.48, P=0.031). On the other hand, there was no significant correlation between RVSWI at rest and 6MWD (R=−0.11, P=0.63) and peak VO2 (R=0.13, P=0.95), and the EQ-VAS (R=0.11, P=0.61). During a median follow-up period of 312 (IQR 176–369) days, adverse events occurred in 3 patients (15%), including 1 death and 2 hospitalisations for major bleeding and right heart failure. Kaplan-Meier analysis revealed that the adverse events more frequently occurred in patients with lower ΔRVSWI compared to those with higher ΔRVSWI (Figure B).

Conclusions

ΔRVSWI was positively correlated with 6MWD, peak VO2 and EQ-VAS irrespective of RV function at rest. Our findings suggest that the assessment of RV reserve function using ΔRVSWI would be useful for risk stratification in patients with LVAD.

Funding Acknowledgement

Type of funding sources: None.