Timing of Regadenoson-induced Peak Hyperemia and the Effects on Coronary Flow Reserve.

Background: Regadenoson is used to induce hyperemia in cardiac imaging, facilitating diagnosis of ischemia and assessment of coronary flow reserve (CFR). While the regadenoson package insert recommends administration of radionuclide tracer 10-20 seconds after injection, peak hyperemia has been observed at approximately 100 seconds after injection in healthy volunteers undergoing cardiovascular magnetic resonance imaging (CMR). It is unclear when peak hyperemia occurs in a patient population. Objectives: The goal of this study was to determine time to peak hyperemia after regadenoson injection in healthy volunteers and patients, and whether the recommended image timing in the package insert underestimates CFR. Methods: Healthy volunteers (n=15) and patients (n=25) underwent stress CMR, including phase-contrast imaging of the coronary sinus at rest and multiple timepoints after 0.4 mg regadenoson injection. Coronary sinus flow (ml/min) was divided by resting values to yield CFR. Smoothed, time-resolved curves for CFR were generated with pointwise 95% confidence intervals. Results: CFR between 60 and 120 seconds was significantly higher than CFR at 30 seconds after regadenoson injection (p < 0.05) as shown by non-overlapping 95% confidence intervals for both healthy volunteers (30 s, [2.8, 3.4]; 60 s, [3.8, 4.4]; 90 s, [4.1, 4.7]; 120 s, [3.6, 4.3]) and patients (30 s, [2.1, 2.5]; 60 s, [2.6, 3.1]; 90 s, [2.7, 3.2]; 120 s, [2.5, 3.1]). Conclusion: Imaging at 90 seconds following regadenoson injection is the optimal approach to capture peak hyperemia. Imaging at 30 seconds, which is more aligned with the package insert recommendation, would yield an underestimate of CFR and confound assessment of microvascular dysfunction.

Computed tomography fractional flow reserve discrepancies with invasive angiography and physiology - Case series.

BACKGROUND: Computed tomography with fractional flow reserve (CT-FFR) is increasingly common in assessing coronary artery disease. CASE PRESENTATION: We report five cases of discrepancies that led to changes in treatment. CONCLUSIONS: This report highlights discordant findings between modalities, which should be considered during the diagnostic assessment of chest pain.

Self-expanding and balloon-expandable valves in low risk TAVR patients.

BACKGROUND: Recent randomized studies have broadened the indication of transcatheter aortic valve replacement (TAVR) to also include low-surgical-risk patients. However, the data on self-expanding (SE) and balloon-expandable (BE) valves in low-risk patients remain sparse. METHODS: The current study is a post hoc analysis of combined data from both LRT 1.0 and 2.0 trials comparing BE and SE transcatheter heart valves. RESULTS: A total of 294 patients received a BE valve, and 102 patients received an SE valve. The 30-day clinical outcomes were similar across both groups except for stroke (4.9% vs. 0.7%, p = 0.014) and permanent pacemaker implantation (17.8% vs. 5.8%, p < 0.001), which were higher in the SE cohort than the BE cohort. No difference was observed in terms of paravalvular leak (≥moderate) between the groups (0% vs. 1.5%, p = 0.577). SE patients had higher aortic valve area (1.92 ± 0.43 mm2 vs. 1.69 ± 0.45 mm2, p < 0.001) and lower mean gradient (8.93 ± 3.53 mmHg vs. 13.41 ± 4.73 mmHg, p < 0.001) than BE patients. In addition, the rate of subclinical leaflet thrombosis was significantly lower in SE patients (5.6% vs. 13.8%, p = 0.038). CONCLUSION: In this non-randomized study assessing SE and BE valves in low-risk TAVR patients, SE valves are associated with better hemodynamics and lesser leaflet thrombosis, with increased rates of stroke and permanent pacemaker implantation at 30 days; however, this could be due to certain patient-dependent factors not fully evaluated in this study. The long-term implications of these outcomes on structural valve durability remain to be further investigated. CLINICAL TRIAL REGISTRY: LRT 1.0: NCT02628899 LRT 2.0: NCT03557242.

Cardiovascular Fellowship Training in Cardio-Obstetrics: JACC Review Topic of the Week.

The United States has the highest maternal mortality in the developed world with cardiovascular disease as the leading cause of pregnancy-related deaths. In response to this, the emerging subspecialty of cardio-obstetrics has been growing over the past decade. Cardiologists with training and expertise in caring for patients with cardiovascular disease in pregnancy are essential to provide effective, comprehensive, multidisciplinary, and high-quality care for this vulnerable population. This document provides a blueprint on incorporation of cardio-obstetrics training into cardiovascular disease fellowship programs to improve knowledge, skill, and expertise among cardiologists caring for these patients, with the goal of improving maternal and fetal outcomes.

Aspirin Versus Warfarin after Transcatheter Aortic Valve Replacement in Low-Risk Patients: 2-Year Follow-Up.

Subclinical leaflet thrombosis occurs with transcatheter heart valves (THVs) and could be associated with structural valve deterioration. The current guidelines recommend the use of antiplatelet agents after transcatheter aortic valve replacement (TAVR) but not the routine use of oral anticoagulation. Our study examines the effects of short-term warfarin therapy on THV hemodynamics at 24 months after TAVR in low-risk patients. Low-risk patients who underwent TAVR were randomly allocated 1:1 to receive low-dose aspirin (n = 50) or low-dose aspirin plus warfarin (n = 44). After 30 days of treatment, ongoing medication regimens, including anticoagulation, were at the physicians' discretion. Follow-up after a period of 24 months was available for clinical and echocardiographic outcomes. At the 24-month mark, follow-up echocardiography of the randomly allocated patients revealed just 1 additional case of new structural valve deterioration in the aspirin group (compared with the occurrence within 30 days), based on the Valve Academic Research Consortium 3 definitions. There were also no differences in mean pressure gradients (11.5 ± 0.5 mm Hg vs 11.05 ± 4.0 mm Hg, p = 0.6) or peak velocity (2.2 ± 0.5 m/s vs 2.1 ± 0.4 m/s, p = 0.7) between the groups. A composite end point (mortality, stroke, and myocardial infarction) did not show any difference between the groups at long-term follow-up (p = 0.07). In conclusion, in low-risk patients who underwent TAVR, short-term anticoagulation with warfarin did not impact clinical outcomes or THV hemodynamics by echocardiography at 24 months.

Transcatheter Aortic Valve Replacement and Impact of Subclinical Leaflet Thrombosis in Low-Risk Patients: LRT Trial 4-Year Outcomes.

BACKGROUND: The LRT trial (Low-Risk Transcatheter Aortic Valve Replacement [TAVR]) demonstrated the safety and feasibility of TAVR in low-risk patients, with excellent 1- and 2-year outcomes. The objective of the current study is to provide the overall clinical outcomes and the impact of 30-day hypoattenuated leaflet thickening (HALT) on structural valve deterioration at 4 years. METHODS: The prospective, multicenter LRT trial was the first Food and Drug Administration-approved investigational device exemption study to evaluate feasibility and safety of TAVR in low-risk patients with symptomatic severe tricuspid aortic stenosis. Clinical outcomes and valve hemodynamics were documented annually through 4 years. RESULTS: A total of 200 patients were enrolled, and follow-up was available on 177 patients at 4 years. The rates of all-cause mortality and cardiovascular death were 11.9% and 3.3%, respectively. The stroke rate rose from 0.5% at 30 days to 7.5% at 4 years, and permanent pacemaker implantation rose from 6.5% at 30 days to 11.7% at 4 years. Endocarditis was detected in 2.5% of the cohort, with no new cases reported between 2 and 4 years. Transcatheter heart valve hemodynamics remained excellent post-procedure and were maintained (mean gradient 12.56±5.54 mm Hg and aortic valve area 1.69±0.52 cm2) at 4 years. At 30 days, HALT was observed in 14% of subjects who received a balloon-expandable transcatheter heart valve. There was no difference in valve hemodynamics between patients with and without HALT (mean gradient 14.94±5.01 mm Hg versus 12.3±5.57 mm Hg; P=0.23) at 4 years. The overall rate of structural valve deterioration was 5.8%, and there was no impact of HALT on valve hemodynamics, endocarditis, or stroke at 4 years. CONCLUSIONS: TAVR in low-risk patients with symptomatic severe tricuspid aortic stenosis was found to be safe and durable at 4 years. Structural valve deterioration rates were low irrespective of the type of valve, and the presence of HALT at 30 days did not affect structural valve deterioration, transcatheter valve hemodynamics, and stroke rate at 4 years. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT02628899.

Coronary Obstruction From TAVR in Native Aortic Stenosis: Development and Validation of Multivariate Prediction Model.

BACKGROUND: Transcatheter aortic valve replacement (TAVR)-related coronary artery obstruction prediction remains unsatisfactory despite high mortality and novel preventive therapies. OBJECTIVES: This study sought to develop a predictive model for TAVR-related coronary obstruction in native aortic stenosis. METHODS: Preprocedure computed tomography and fluoroscopy images of patients in whom TAVR caused coronary artery obstruction were collected. Central laboratories made measurements, which were compared with unobstructed patients from a single-center database. A multivariate model was developed and validated against a 1:1 propensity-matched subselection of the unobstructed cohort. RESULTS: Sixty patients with angiographically confirmed coronary obstruction and 1,381 without obstruction were included. In-hospital death was higher in the obstruction cohort (26.7% vs 0.7%; P < 0.001). Annular area and perimeter, coronary height, sinus width, and sinotubular junction height and width were all significantly smaller in the obstructed cohort. Obstruction was most common on the left side (78.3%) and at the level of the coronary artery ostium (92.1%). Coronary artery height and sinus width, but not annulus area, were significant risk factors for obstruction by logistic regression but performed poorly in predicting obstruction. The new multivariate model (coronary obstruction IF cusp height > coronary height, AND virtual valve-to-coronary distance ≤4 mm OR culprit leaflet calcium volume >600 mm3) performed well, with an area under the curve of 0.93 (sensitivity = 0.93, specificity = 0.84) for the left coronary artery and 0.94 (sensitivity = 0.92, specificity = 0.96) for the right. CONCLUSIONS: A novel computed tomography-based multivariate prediction model that can be implemented routinely in real-world practice predicted coronary artery obstruction from TAVR in native aortic stenosis.

TAVR in 2023: Who Should Not Get It?

Since the first transcatheter delivery of an aortic valve prosthesis was performed by Cribier et al in 2002, the picture of aortic stenosis (AS) therapeutics has changed dramatically. Initiated from an indication of inoperable to high surgical risk, extending to intermediate and low risk, transcatheter aortic valve replacement (TAVR) is now an approved treatment for patients with severe, symptomatic AS across all the risk categories. The current evidence supports TAVR as a frontline therapy for treating severe AS. The crucial question remains concerning the subset of patients who still are not ideal candidates for TAVR because of certain inherent anatomic, nonmodifiable, and procedure-specific factors. Therefore, in this study, we focus on these scenarios and reasons for referring selected patients for surgical aortic valve replacement in 2023.

Subclinical leaflet thrombosis and antithrombotic therapy post-TAVI: An LRT substudy.

BACKGROUND: Subclinical leaflet thrombosis (SLT) is characterized on computed tomography (CT) imaging as hypoattenuated leaflet thickening (HALT), reduced leaflet motion (RELM), and hypoattenuation affecting motion (HAM). How antithrombotic regimen type impacts SLT remains poorly understood. We evaluated how antithrombotic regimen type impacts SLT in low-risk subjects following transcatheter aortic valve implantation (TAVI). METHODS: This substudy is a post hoc analysis of the LRT 1.0 and 2.0 trials to assess SLT in subjects who underwent CT or transoesophageal echocardiogram (TOE) imaging at 30 days, stratified by antithrombotic regimen received (single antiplatelet therapy [SAPT], dual antiplatelet therapy [DAPT], or oral anticoagulation). We also utilized univariable logistic regression modelling to identify echocardiographic predictors of HALT. RESULTS: Rates of HALT, RELM, and HAM were all significantly lower with oral anticoagulation compared to SAPT or DAPT at 30 days (HALT: 2.6% vs 14.3% vs 17.2%, respectively, with p < 0.001; RELM: 1.8% vs 9.6% vs 13.1%, respectively, with p = 0.004; and HAM: 0.9% vs 8.5% vs 9.8%, respectively, with p = 0.011). Additionally, short-term oral anticoagulation was not associated with higher bleeding rates compared to SAPT or DAPT (0.8% vs. 1.8% vs. 3.6%, p = 0.291). The presence of HALT did not significantly impact echocardiographic haemodynamic parameters at 30 days. CONCLUSION: This is the largest study to date that evaluated the impact of different antithrombotic regimens on SLT in low-risk TAVI patients. Oral anticoagulation was associated with significantly lower rates of SLT at 30 days compared to DAPT or SAPT, and there was no apparent benefit of DAPT over SAPT.

Impact of Virtual Interviewing on Geographic Placement for Cardiology Fellowship Recruitment.

Background Virtual interviewing for cardiology fellowship was instituted in the 2021 fellowship application cycle because of the COVID-19 pandemic and restricted travel. The impact on geographic patterns of fellow-training program matching is unknown. This study sought to determine if there was a difference in geographic placement of matched fellows for cardiology fellowship match after initiation of virtual interviews compared with in-person interviewing. Methods and Results All US-based accredited cardiovascular disease fellowship programs that participated in the 2019 to 2021 fellowship match cycles and had publicly available data with fellowship and residency training locations and training year were included. Each fellow was categorized based on whether their fellowship and residency programs were in the same institution, same state, same US census region, or different census region. Categories were mutually exclusive. Of 236 eligible programs, 118 (50%) programs were identified, composed of 1787 matched fellows. Compared with the previrtual cohort (n=1178 matched fellows), there was no difference in the geographic placement during the 2021 virtual cycle (n=609 matched fellows) (P=0.19), including the proportion matched at the same program (30.6% versus 31.5%), same state but different program (13% versus 13.8%), same region but different state (24.2% versus 19.7%), or different region (35% versus 33.1%). There was also no difference when stratified by program size or geographic region. Conclusions The use of virtual interviewing in the 2021 cardiology fellowship application cycle showed no significant difference in the geographic placement of matched fellows compared with in-person interviewing. Further study is needed to evaluate the impact of virtual interviewing and optimize its use in fellowship recruitment.

A Word of Caution Before Treating Aortic Stenosis in Patients With Concomitant LVOT Obstruction.

Patients with aortic stenosis and concomitant left ventricular outflow tract obstruction undergoing transcatheter aortic valve replacement are at risk of hemodynamic collapse after the procedure due to worsening left ventricular outflow tract obstruction. We present 3 cases highlighting the important interplay between these 2 disease states and associated diagnostic and treatment challenges. (Level of Difficulty: Advanced.).

Impact of left ventricular outflow tract calcium on valve geometry in self-expanding transcatheter aortic-valve replacement.

OBJECTIVES: Evaluate transcatheter heart valve (THV) geometry according to left ventricular outflow tract (LVOT) calcium degree and its impact on hemodynamics and outcomes in patients undergoing transcatheter aortic valve replacement (TAVR) with a contemporary self-expanding THV. BACKGROUND: LVOT calcium remains challenging for contemporary THVs. LVOT calcium location and degree may affect THV deployment and impact flow patterns and shear stress, accelerating THV degeneration. METHODS: EPROMPT (CoreValve Evolut Pro Prospective Registry; NCT03423459) is a prospective, investigator-initiated, multicenter registry of patients undergoing TAVR using CoreValve Evolut PRO/PRO + THVs. A total of 107 patients were enrolled in EPROMPT's computed tomography (CT) cohort between January 2018 and October 2021. These patients underwent follow-up CT scan 30 days post-TAVR. We analyzed THV geometry and its interaction with the aortic root following deployment using 30-day post-TAVR CT in patients with none/mild versus moderate/severe LVOT calcium. RESULTS: Thirty-day THV inflows were less eccentric in the short axis in patients with none/mild versus moderate/severe LVOT calcium (1.16 ± 0.09 vs. 1.21 ± 0.12; p = 0.007). THV became more circular and was similar between both cohorts at the THV waist (1.08 ± 0.06 vs. 1.09 ± 0.11; p = 0.551), leaflet tips (1.03 ± 0.04 vs. 1.05 ± 0.09; p = 0.299), and THV outflow (1.04 ± 2.2 vs. 1.03 ± 2.7; p = 0.143). Thirty-day > mild paravalvular leak was low in both cohorts (1.5% vs. 2.4%; p = 0.724); mean gradients were similar (7.7 ± 3.6 vs. 7.7 ± 3.4 mmHg; p = 0.955). CONCLUSIONS: Despite inflow deformities observed in patients with moderate/severe LVOT calcium, Evolut PRO/PRO + conforms to elliptical aortic annuli, maintaining circularity and proper function at the leaflets and outflow, even in patients with moderate/severe LVOT calcium.

Lifetime management of patients with symptomatic severe aortic stenosis: a computed tomography simulation study.

BACKGROUND: Given enough time, transcatheter heart valves (THVs) will degenerate and may require reintervention. Redo transcatheter aortic valve implantation (TAVI) is an attractive strategy but carries a risk of coronary obstruction. AIMS: We sought to predict how many TAVIs patients could undergo in their lifetime using computed tomography (CT) simulation. METHODS: We analysed paired CT scans (baseline and 30 days post-TAVI) from patients in the LRT trial and EPROMPT registry. We implanted virtual THVs on baseline CTs, comparing predicted valve-to-coronary (VTC) distances to 30-day CT VTC distances to evaluate the accuracy of CT simulation. We then simulated implantation of a second virtual THV within the first to estimate the risk of coronary obstruction due to sinus sequestration and the need for leaflet modification. RESULTS: We included 213 patients with evaluable paired CTs. There was good agreement between virtual (baseline) and actual (30 days) CT measurements. CT simulation of TAVI followed by redo TAVI predicted low coronary obstruction risk in 25.4% of patients and high risk, likely necessitating leaflet modification, in 27.7%, regardless of THV type. The remaining 46.9% could undergo redo TAVI so long as the first THV was balloon-expandable but would likely require leaflet modification if the first THV was self-expanding. CONCLUSIONS: Using cardiac CT simulation, it is possible to predict whether a patient can undergo multiple TAVI procedures in their lifetime. Those who cannot may prefer to undergo surgery first. CT simulation could provide a personalised lifetime management strategy for younger patients with symptomatic severe aortic stenosis and inform decision-making. CLINICALTRIALS: gov: NCT02628899; ClinicalTrials.gov: NCT03557242; ClinicalTrials.gov: NCT03423459.

Impact of Left Ventricular Outflow Tract Calcium on Hemodynamics and Outcomes in Patients After Transcatheter Aortic Valve Implantation With a Contemporary Self-Expanding Valve.

Left ventricular outflow tract (LVOT) calcium remains a challenge for transcatheter aortic valve implantation (TAVI) and is associated with an increased risk of debris embolization, permanent pacemaker requirement, and annular rupture. We report the results of the (EPROMPT) CoreValve Evolut PRO Prospective Registry, which sought to evaluate the real-world performance of the CoreValve Evolut PRO transcatheter heart valve (THV) according to computed tomography-defined extent of LVOT calcium. The prospective, investigator-initiated, multicenter registry includes patients who underwent TAVI using the CoreValve Evolut PRO/PRO+ THV system. Analyzed patients were dichotomized on the basis of the severity of their LVOT calcium at baseline (none/mild vs moderate/severe). Patients were followed with 30-day clinical assessment and echocardiography. Of the 277 patients included, 177 had computed tomography-defined none/mild LVOT calcium (63.9%), and 100 had moderate/severe LVOT calcium (36.1%). Device success was similar in both cohorts (97.7% vs 95.0%; p = 0.217). Stroke rates were numerically higher in the moderate/severe LVOT calcium cohort (in-hospital and 30 day: 1.7% vs 4.0%; p = 0.240). Patients with none/mild LVOT calcium had higher rates of permanent pacemaker implantation (in-hospital: 21.5% vs 9.0%; p = 0.008 and 30-day: 22.0% vs 12.0%; p = 0.027). At 30 days, there were numerically higher rates of >mild paravalvular leak in patients with moderate/severe LVOT calcium (1.7% vs 4.0%; p = 0.240). Thirty-day mean gradients were similar (7.5 vs 7.6 mm Hg; p = 0.782). In conclusion, patients in the EPROMPT registry receiving the contemporary self-expanding CoreValve Evolut PRO/PRO+ THV demonstrated similar short-term outcomes and hemodynamics across the entire spectrum of LVOT calcium.