Transcatheter Aortic-Valve Replacement in Low-Risk Patients at Five Years.

BACKGROUND: A previous analysis in this trial showed that among patients with severe, symptomatic aortic stenosis who were at low surgical risk, the rate of the composite end point of death, stroke, or rehospitalization at 1 year was significantly lower with transcatheter aortic-valve replacement (TAVR) than with surgical aortic-valve replacement. Longer-term outcomes are unknown. METHODS: We randomly assigned patients with severe, symptomatic aortic stenosis and low surgical risk to undergo either TAVR or surgery. The first primary end point was a composite of death, stroke, or rehospitalization related to the valve, the procedure, or heart failure. The second primary end point was a hierarchical composite that included death, disabling stroke, nondisabling stroke, and the number of rehospitalization days, analyzed with the use of a win ratio analysis. Clinical, echocardiographic, and health-status outcomes were assessed through 5 years. RESULTS: A total of 1000 patients underwent randomization: 503 patients were assigned to undergo TAVR, and 497 to undergo surgery. A component of the first primary end point occurred in 111 of 496 patients in the TAVR group and in 117 of 454 patients in the surgery group (Kaplan-Meier estimates, 22.8% in the TAVR group and 27.2% in the surgery group; difference, -4.3 percentage points; 95% confidence interval [CI], -9.9 to 1.3; P = 0.07). The win ratio for the second primary end point was 1.17 (95% CI, 0.90 to 1.51; P = 0.25). The Kaplan-Meier estimates for the components of the first primary end point were as follows: death, 10.0% in the TAVR group and 8.2% in the surgery group; stroke, 5.8% and 6.4%, respectively; and rehospitalization, 13.7% and 17.4%. The hemodynamic performance of the valve, assessed according to the mean (±SD) valve gradient, was 12.8±6.5 mm Hg in the TAVR group and 11.7±5.6 mm Hg in the surgery group. Bioprosthetic-valve failure occurred in 3.3% of the patients in the TAVR group and in 3.8% of those in the surgery group. CONCLUSIONS: Among low-risk patients with severe, symptomatic aortic stenosis who underwent TAVR or surgery, there was no significant between-group difference in the two primary composite outcomes. (Funded by Edwards Lifesciences; PARTNER 3 ClinicalTrials.gov number, NCT02675114.).

Interval Changes in 4D Flow-Derived in vivo Hemodynamics Stratify Aortic Growth in Type B Aortic Dissection Patients.

BACKGROUND: Aortic diameter growth in type B aortic dissection (TBAD) is associated with progressive aortic dilation, resulting in increased mortality in patients with both de novo TBAD (dnTBAD) and residual dissection after type A dissection repair (rTAAD). Preemptive thoracic endovascular aortic repair may improve mortality in patients with TBAD, although it is unclear which patients may benefit most from early intervention. In vivo hemodynamic assessment using four-dimensional (4D) flow magnetic resonance imaging (MRI) has been used to characterize TBAD patients with growing aortas. In this longitudinal study, we investigated whether changes over time in 4D flow derived true and false lumen (TL, FL) hemodynamic parameters correlate with aortic growth rate which is a marker of increased risk. METHODS: We retrospectively identified TBAD patients with baseline and follow-up 4D flow MRI at least 120 days apart. Patients with TBAD intervention before baseline or between scans were excluded. 4D flow MRI data analysis included segmentation of the TL and FL, followed by voxel-wise calculation of TL and FL total kinetic energy (KE), maximum velocity (MV), mean forward flow (FF), and mean reverse flow (RF). Changes over time (Δ) were calculated for all hemodynamic parameters. Maximal diameter in the descending aorta was measured from MR angiogram images acquired at the time of 4D flow. Aortic growth rate was defined as the change in diameter divided by baseline diameter and standardized to scan interval. RESULTS: 32 patients met inclusion criteria (age: 56.9±14.1 years, Female: 13, n=19 rTAAD, n=13 dnTBAD). Mean follow up time was 538 days (range: 135-1689). Baseline aortic diameter did not correlate with growth rate. In the entire cohort, Δ FL MV (rho=0.37, p=.04) and Δ FL RF (rho=0.45, p=0.01) correlated with growth rate. In rTAAD only, Δ FL MV (rho=0.48, p=.04) and Δ FL RF (rho=0.51, p=0.03) correlated with growth rate, while in dnTBAD only, Δ TL KE (rho=0.63, p=.02) and Δ TL MV (rho=0.69, p=.01) correlated with growth rate. CONCLUSIONS: 4D flow derived longitudinal hemodynamic changes correlate with aortic growth rate in TBAD and may provide additional prognostic value for risk stratification. 4D flow MRI could be integrated into existing imaging protocols to allow for identification of TBAD patients who would benefit from preemptive surgical or endovascular intervention.

Hemodynamic Evaluation of Type B Aortic Dissection Using Compressed Sensing Accelerated 4D Flow MRI.

BACKGROUND: 4D Flow MRI is a quantitative imaging technique to evaluate blood flow patterns; however, it is unclear how compressed sensing (CS) acceleration would impact aortic hemodynamic quantification in type B aortic dissection (TBAD). PURPOSE: To investigate CS-accelerated 4D Flow MRI performance compared to GRAPP-accelerated 4D Flow MRI (GRAPPA) to evaluate aortic hemodynamics in TBAD. STUDY TYPE: Prospective. POPULATION: Twelve TBAD patients, two volunteers. FIELD STRENGTH/SEQUENCE: 1.5T, 3D time-resolved cine phase-contrast gradient echo sequence. ASSESSMENT: GRAPPA (acceleration factor [R] = 2) and two CS-accelerated (R = 7.7 [CS7.7] and 10.2 [CS10.2]) 4D Flow MRI scans were acquired twice for interscan reproducibility assessment. Voxelwise kinetic energy (KE), peak velocity (PV), forward flow (FF), reverse flow (RF), and stasis were calculated. Plane-based mid-lumen flows were quantified. Imaging times were recorded. TESTS: Repeated measures analysis of variance, Pearson correlation coefficients (r), intraclass correlation coefficients (ICC). P < 0.05 indicated statistical significance. RESULTS: The KE and FF in true lumen (TL) and PV in false lumen (FL) did not show difference among three acquisition types (P = 0.818, 0.065, 0.284 respectively). The PV and stasis in TL were higher, KE, FF, and RF in FL were lower, and stasis was higher in GRAPPA compared to CS7.7 and CS10.2. The RF was lower in GRAPPA compared to CS10.2. The correlation coefficients were strong in TL (r = [0.781-0.986]), and low to strong in FL (r = [0.347-0.948]). The ICC levels demonstrated moderate to excellent interscan reproducibility (0.732-0.989). The FF and net flow in mid-descending aorta TL were significantly different between CS7.7 and CS10.2. CONCLUSION: CS-accelerated 4D Flow MRI has potential for clinical utilization with shorter scan times in TBAD. Our results suggest similar hemodynamic trends between acceleration types, but CS-acceleration impacts KE, FF, RF, and stasis more in FL. EVIDENCE LEVEL: 1 Technical Efficacy: Stage 2.

Systolic reverse flow derived from 4D flow cardiovascular magnetic resonance in bicuspid aortic valve is associated with aortic dilation and aortic valve stenosis: a cross sectional study in 655 subjects.

BACKGROUND: Bicuspid aortic valve (BAV) disease is associated with increased risk of aortopathy. In addition to current intervention guidelines, BAV mediated changes in aortic 3D hemodynamics have been considered as risk stratification measures. We aimed to evaluate the association of 4D flow cardiovascular magnetic resonance (CMR) derived voxel-wise aortic reverse flow with aortic dilation and to investigate the role of aortic valve regurgitation (AR) and stenosis (AS) on reverse flow in systole and diastole. METHODS: 510 patients with BAV (52 ± 14 years) and 120 patients with trileaflet aortic valve (TAV) (61 ± 11 years) and mid-ascending aorta diameter (MAAD) > 35 mm who underwent CMR including 4D flow CMR were retrospectively included. An age and sex-matched healthy control cohort (n = 25, 49 ± 12 years) was selected. Voxel-wise reverse flow was calculated in the aorta and quantified by the mean reverse flow in the ascending aorta (AAo) during systole and diastole. RESULTS: BAV patients without AS and AR demonstrated significantly increased systolic and diastolic reverse flow (222% and 13% increases respectively, p < 0.01) compared to healthy controls and also had significantly increased systolic reverse flow compared to TAV patients with aortic dilation (79% increase, p < 0.01). In patients with isolated AR, systolic and diastolic AAo reverse flow increased significantly with AR severity (c = - 83.2 and c = - 205.6, p < 0.001). In patients with isolated AS, AS severity was associated with an increase in both systolic (c = - 253.1, p < 0.001) and diastolic (c = - 87.0, p = 0.02) AAo reverse flow. Right and left/right and non-coronary fusion phenotype showed elevated systolic reverse flow (> 17% increase, p < 0.01). Right and non-coronary fusion phenotype showed decreased diastolic reverse flow (> 27% decrease, p < 0.01). MAAD was an independent predictor of systolic (p < 0.001), but not diastolic, reverse flow (p > 0.1). CONCLUSION: 4D flow CMR derived reverse flow associated with BAV was successfully captured even in the absence of AR or AS and in comparison to TAV patients with aortic dilation. Diastolic AAo reverse flow increased with AR severity while AS severity strongly correlated with increased systolic reverse flow in the AAo. Additionally, increasing MAAD was independently associated with increasing systolic AAo reverse flow. Thus, systolic AAo reverse flow may be a valuable metric for evaluating disease severity in future longitudinal outcome studies.

Limited versus full sternotomy for aortic valve replacement.

BACKGROUND: Aortic valve disease is a common condition easily treatable with cardiac surgery. This is conventionally performed by opening the sternum ('median sternotomy') and replacing the valve under cardiopulmonary bypass. Median sternotomy is well tolerated, but as less invasive options become available, the efficacy of limited incisions has been called into question. In particular, the effects of reducing the visibility and surgical access have raised safety concerns with regard to the placement of cannulae, venting of the heart, epicardial wire placement, and de-airing of the heart at the end of the procedure. These difficulties may increase operating times, affecting outcome. The benefits of smaller incisions are thought to include decreased pain; improved respiratory mechanics; reductions in wound infections, bleeding, and need for transfusion; shorter intensive care stay; better cosmesis; and a quicker return to normal activity. This is an update of a Cochrane review first published in 2017, with seven new studies. OBJECTIVES: To assess the effects of minimally invasive aortic valve replacement via a limited sternotomy versus conventional aortic valve replacement via median sternotomy in people with aortic valve disease requiring surgical replacement. SEARCH METHODS: We performed searches of CENTRAL, MEDLINE and Embase from inception to August 2021, with no language limitations. We also searched two clinical trials registries and manufacturers' websites. We reviewed references of primary studies to identify any further studies of relevance. SELECTION CRITERIA: We included randomised controlled trials comparing aortic valve replacement via a median sternotomy versus aortic valve replacement via a limited sternotomy. We excluded trials that performed other minimally invasive incisions such as mini-thoracotomies, port access, transapical, transfemoral or robotic procedures. Although some well-conducted prospective and retrospective case-control and cohort studies exist, these were not included in this review. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trial papers to extract data, assess quality, and identify risk of bias. A third review author provided arbitration where required. We determined the certainty of evidence using the GRADE methodology and summarised results of patient-relevant outcomes in a summary of findings table. MAIN RESULTS: The review included 14 trials with 1395 participants. Most studies had at least two domains at high risk of bias. We analysed 14 outcomes investigating the effects of minimally invasive limited upper hemi-sternotomy on aortic valve replacement as compared to surgery performed via full median sternotomy. Upper hemi-sternotomy may have little to no effect on mortality versus full median sternotomy (risk ratio (RR) 0.93, 95% confidence interval (CI) 0.45 to 1.94; 10 studies, 985 participants; low-certainty evidence). Upper hemi-sternotomy for aortic valve replacement may increase cardiopulmonary bypass time slightly, although the evidence is very uncertain (mean difference (MD) 10.63 minutes, 95% CI 3.39 to 17.88; 10 studies, 1043 participants; very low-certainty evidence) and may increase aortic cross-clamp time slightly (MD 6.07 minutes, 95% CI 0.79 to 11.35; 12 studies, 1235 participants; very low-certainty evidence), although the evidence is very uncertain. Most studies had at least two domains at high risk of bias. Postoperative blood loss was probably lower in the upper hemi-sternotomy group (MD -153 mL, 95% CI -246 to -60; 8 studies, 767 participants; moderate-certainty evidence). Low-certainty evidence suggested that there may be no change in pain scores by upper hemi-sternotomy (standardised mean difference (SMD) -0.19, 95% CI -0.43 to 0.04; 5 studies, 649 participants). Upper hemi-sternotomy may result in little to no difference in quality of life (MD 0.03 higher, 95% CI 0 to 0.06 higher; 4 studies, 624 participants; low-certainty evidence). Two studies reporting index admission costs concluded that limited sternotomy may be more costly at index admission in the UK National Health Service (MD 1190 GBP more, 95% CI 420 GBP to 1970 GBP, 2 studies, 492 participants; low-certainty evidence). AUTHORS' CONCLUSIONS: The evidence was of very low to moderate certainty. Sample sizes were small and underpowered to demonstrate differences in some outcomes. Clinical heterogeneity was also noted. Considering these limitations, there may be little to no effect on mortality. Differences in extracorporeal support times are uncertain, comparing upper hemi-sternotomy to full sternotomy for aortic valve replacement. Before widespread adoption of the minimally invasive approach can be recommended, there is a need for a well-designed and adequately powered prospective randomised controlled trial. Such a study would benefit from also performing a robust cost analysis. Growing patient preference for minimally invasive techniques merits thorough quality of life analyses to be included as end points, as well as quantitative measures of physiological reserve.

Implementation of a direct-to-operating room aortic emergency transfer program: Expedited management of type A aortic dissection.

INTRODUCTION: Type A Aortic Dissection (TAAD) is a surgical emergency with a time-dependent rate of mortality. We hypothesized that a direct-to-operating room (DOR) transfer program for patients with TAAD would reduce time to intervention. METHODS: A DOR program was started at an urban tertiary care hospital in February 2020. We performed a retrospective study of adult patients undergoing treatment for TAAD before (n = 42) and after (n = 84) implementation of DOR. Expected mortality was calculated using the International Registry of Acute Aortic Dissection risk prediction model. RESULTS: Median time from acceptance of transfer from emergency physician to operating room arrival was 1.37 h (82 min) faster in DOR compared to pre-DOR (1.93 h vs 3.30 h, p < 0.001). Median time from arrival to operating room was 1.14 h (72 min) faster after DOR compared to pre-DOR (0.17 h vs 1.31 h, p < 0.001). In-hospital mortality was 16.2% in pre-DOR, with an observed-to-expected (O/E) ratio of 1.03 (p = 0.24) and 12.0% in the DOR group, with an O/E ratio of 0.59 (p < 0.001). CONCLUSION: Creation of a DOR program resulted in decreased time to intervention. This was associated with a decrease in observed-to-expected operative mortality. The transfer of patients with acute type A aortic dissection to centers with direct-to-OR programs may result in decreased time from diagnosis to surgery.

Transcatheter Aortic-Valve Replacement with a Balloon-Expandable Valve in Low-Risk Patients.

BACKGROUND: Among patients with aortic stenosis who are at intermediate or high risk for death with surgery, major outcomes are similar with transcatheter aortic-valve replacement (TAVR) and surgical aortic-valve replacement. There is insufficient evidence regarding the comparison of the two procedures in patients who are at low risk. METHODS: We randomly assigned patients with severe aortic stenosis and low surgical risk to undergo either TAVR with transfemoral placement of a balloon-expandable valve or surgery. The primary end point was a composite of death, stroke, or rehospitalization at 1 year. Both noninferiority testing (with a prespecified margin of 6 percentage points) and superiority testing were performed in the as-treated population. RESULTS: At 71 centers, 1000 patients underwent randomization. The mean age of the patients was 73 years, and the mean Society of Thoracic Surgeons risk score was 1.9% (with scores ranging from 0 to 100% and higher scores indicating a greater risk of death within 30 days after the procedure). The Kaplan-Meier estimate of the rate of the primary composite end point at 1 year was significantly lower in the TAVR group than in the surgery group (8.5% vs. 15.1%; absolute difference, -6.6 percentage points; 95% confidence interval [CI], -10.8 to -2.5; P<0.001 for noninferiority; hazard ratio, 0.54; 95% CI, 0.37 to 0.79; P = 0.001 for superiority). At 30 days, TAVR resulted in a lower rate of stroke than surgery (P = 0.02) and in lower rates of death or stroke (P = 0.01) and new-onset atrial fibrillation (P<0.001). TAVR also resulted in a shorter index hospitalization than surgery (P<0.001) and in a lower risk of a poor treatment outcome (death or a low Kansas City Cardiomyopathy Questionnaire score) at 30 days (P<0.001). There were no significant between-group differences in major vascular complications, new permanent pacemaker insertions, or moderate or severe paravalvular regurgitation. CONCLUSIONS: Among patients with severe aortic stenosis who were at low surgical risk, the rate of the composite of death, stroke, or rehospitalization at 1 year was significantly lower with TAVR than with surgery. (Funded by Edwards Lifesciences; PARTNER 3 ClinicalTrials.gov number, NCT02675114.).

A history of collaboration between electrophysiologists and arrhythmia surgeons.

INTRODUCTION: The notion that medically-refractory arrhythmias might one day be amenable to interventional therapy slowly began to appear in the early 1960's. At that time, there were no "interventional electrophysiologists" or "arrhythmia surgeons" and there was little appreciation of the relationship between anatomy and electrophysiology outside the heart's specialized conduction system. METHODS: In this review, we describe the evolution of collaboration between electrophysiologists and surgeons. RESULTS: Although accessory atrio-ventricular (AV) connections were first identified in 1893 and the Wolff-Parkinson-White (WPW) syndrome was described 37 years later (1930), it was another 37 years (1967) before those anatomic AV connections were proven to be responsible for the clinical syndrome. The success of the subsequent surgical procedures for the WPW syndrome, AV node reentry tachycardia, automatic atrial tachycardias, ischemic and non-ischemic ventricular tachycardias and atrial fibrillation over the next two decades depended on a close, sometimes daily, collaboration between electrophysiologists and surgeons. In the past two decades, that tight collaboration was largely abandoned until the recent introduction of "hybrid procedures" for the treatment of atrial fibrillation. CONCLUSIONS: A retrospective assessment of the 50 years of interventional therapy for arrhythmias clearly demonstrates the clinical benefits of a close collaboration between electrophysiologists and arrhythmia surgeons, regardless of which one is actually performing the intervention.

Four-dimensional magnetic resonance after ascending aorta replacement and aortic valve repair with HAART 300 internal annuloplasty ring.

BACKGROUND: The hemispherical aortic annuloplasty reconstructive technology (HAART) is an internal geometric annuloplasty ring designed to restore a natural elliptical shape to the aortic annulus as part of aortic valve repair. We present four-dimensional flow hemodynamic analysis before and after implementation of the HAART ring in patients undergoing ascending aortic replacement. METHODS: Aortic hemodynamics over the cardiac cycle were visualized using time-resolved three-dimensional pathlines. Velocity streamlines tangent to the time-resolved velocity vector field were used to demonstrate instantaneous aortic hemodynamics. Peak velocities, forward and retrograde flow were calculated at nine planes placed along the midline of the thoracic aorta. Systolic wall shear stress and peak viscous energy loss over the cardiac cycle were calculated. RESULTS: HAART patients displayed similar or improved flow profiles after surgery when compared to a patient undergoing ascending aortic replacement alone. CONCLUSION: There may be a trend towards improved flow dynamics in patients undergoing HAART ring implantation.

Valve-sparing versus valve-replacing aortic root replacement in patients with aortic root aneurysm.

BACKGROUND: Valve-sparing aortic root replacement (VSARR) is an alternative to valve-replacing aortic root replacement (VRARR) with valved-conduits based on recent guidelines for clinical practice. This study investigated outcomes of these two procedures in patients with nonstenotic valves. METHODS: Between January 7, 2007 and June 30, 2019, 475 patients with aortic root aneurysm without aortic stenosis underwent VSARR (151) or VRARR (324) techniques. Propensity score-matching (PSM) was used to alleviate confounding. Endpoints were 30-day mortality, 8-year survival and reoperation, aortic regurgitation, and valve gradients. RESULTS: PSM created 69 pairs of patients with a mean age 52 ± 13 years (10.1% Marfan syndrome, 34.8% bicuspid aortic valve). There was no statistically significant difference in major perioperative morbidity or 30-day mortality (0% VSARR vs. 1.4% VRARR; p = 0.316). Overall survival was significantly higher (p = 0.025) in the VSARR group versus the VRARR group (8-year estimates 100% vs. 88.9%, respectively), while freedom from valve reoperation was similar (p = 0.97, 8-year estimates 90.9% vs. 96.7%, respectively). Freedom from > moderate-severe AR was not significantly different (p = 0.08, 8-year estimates 90.0% VSARR group vs. 100% VRARR), but mean valve gradients at last follow-up were better in the VSARR group (5.9 vs. 13.2 mmHg, p < 0.001). CONCLUSIONS: VSARR is a safe operation in patients with aortic root aneurysm and nonstenotic aortic valves in the hands of experienced surgeons. Freedom from reoperation is similar and the mode of aortic valve failure differs between the two groups.

Echocardiographic Results of Transcatheter Versus Surgical Aortic Valve Replacement in Low-Risk Patients: The PARTNER 3 Trial.

BACKGROUND: This study aimed to compare echocardiographic findings in low-risk patients with severe aortic stenosis after surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR). METHODS: The PARTNER 3 trial (Placement of Aortic Transcatheter Valves) randomized 1000 patients with severe aortic stenosis and low surgical risk to undergo either transfemoral TAVR with the balloon-expandable SAPIEN 3 valve or SAVR. Transthoracic echocardiograms obtained at baseline and at 30 days and 1 year after the procedure were analyzed by a consortium of 2 echocardiography core laboratories. RESULTS: The percentage of moderate or severe aortic regurgitation (AR) was low and not statistically different between the TAVR and SAVR groups at 30 days (0.8% versus 0.2%; P=0.38). Mild AR was more frequent after TAVR than SAVR at 30 days (28.8% versus 4.2%; P<0.001). At 1 year, mean transvalvular gradient (13.7±5.6 versus 11.6±5.0 mm Hg; P=0.12) and aortic valve area (1.72±0.37 versus 1.76±0.42 cm2; P=0.12) were similar in TAVR and SAVR. The percentage of severe prosthesis-patient mismatch at 30 days was low and similar between TAVR and SAVR (4.6 versus 6.3%; P=0.30). Valvulo-arterial impedance (Zva), which reflects total left ventricular hemodynamic burden, was lower with TAVR than SAVR at 1 year (3.7±0.8 versus 3.9±0.9 mm Hg/mL/m2; P<0.001). Tricuspid annulus plane systolic excursion decreased and the percentage of moderate or severe tricuspid regurgitation increased from baseline to 1 year in SAVR but remained unchanged in TAVR. Irrespective of treatment arm, high Zva and low tricuspid annulus plane systolic excursion, but not moderate to severe AR or severe prosthesis-patient mismatch, were associated with increased risk of the composite end point of mortality, stroke, and rehospitalization at 1 year. CONCLUSIONS: In patients with severe aortic stenosis and low surgical risk, TAVR with the SAPIEN 3 valve was associated with similar percentage of moderate or severe AR compared with SAVR but higher percentage of mild AR. Transprosthetic gradients, valve areas, percentage of severe prosthesis-patient mismatch, and left ventricular mass regression were similar in TAVR and SAVR. SAVR was associated with significant deterioration of right ventricular systolic function and greater tricuspid regurgitation, which persisted at 1 year. High Zva and low tricuspid annulus plane systolic excursion were associated with worse outcome at 1 year whereas AR and severe prosthesis-patient mismatch were not. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02675114.

4D flow MRI after aortic replacement with frozen elephant trunk using thoraflex hybrid graft.

Four-dimensional (4D) flow magnetic resonance imaging (MRI) has not been used to describe flow through a Thoraflex Hybrid graft. We present the first 4D flow MRI depiction of Thoraflex Hybrid graft after use as a frozen elephant trunk to repair a DeBakey Type I aortic dissection.

Impact of age, sex, and global function on normal aortic hemodynamics.

PURPOSE: To examine the effects of age, sex, and left ventricular global function on velocity, helicity, and 3D wall shear stress (3D-WSS) in the aorta of N = 100 healthy controls. METHODS: Fifty female and 50 male volunteers with no history of cardiovascular disease, with 10 volunteers per age group (18-30, 31-40, 41-50, 51-60, and 61-80 years) underwent aortic 4D-flow MRI. Quantification of systolic aortic peak velocity, helicity, and 3D-WSS distribution and the calculation of age group-averaged peak systolic velocity and 3D-WSS maps ("atlases") were computed. Age-related and sex-related changes in peak velocity, helicity, and 3D-WSS were computed and correlated with standard metrics of left ventricular function derived from short-axis cine MRI. RESULTS: No significant differences were found in peak systolic velocity or 3D-WSS based on sex except for the 18- to 30-year-old group (males 8% higher velocity volume and 3D-WSS surface area). Between successively older groups, systolic velocity decreased (13%, <1%, 7%, and 55% of the aorta volume) and 3D-WSS decreased (21%, 2%, 30%, and 62% of the aorta surface area). Mean velocity, mean 3D-3D-WSS, and median helicity increased with cardiac output (r = 0.27-0.43, all P < .01), and mean velocity and 3D-WSS decreased with increasing diameter (r > 0.35, P < .001). Arch and descending aorta systolic mean velocity, mean 3D-WSS, and median helicity increased with normalized left ventricular volumes: end diastolic volume (r = 0.31-0.37, P < .01), end systolic volume (r = 0.27-0.35, P < .01), and stroke volume (r = 0.28-0.35, P < .01). CONCLUSION: Healthy aortic hemodynamics are dependent on subject age, and correlate with vessel diameter and cardiac function.

Parametric Hemodynamic 4D Flow MRI Maps for the Characterization of Chronic Thoracic Descending Aortic Dissection.

BACKGROUND: Systematic evaluation of complex flow in the true lumen and false lumen (TL, FL) is needed to better understand which patients with chronic descending aortic dissection (DAD) are predisposed to complications. PURPOSE: To develop quantitative hemodynamic maps from 4D flow MRI for evaluating TL and FL flow characteristics. STUDY TYPE: Retrospective. POPULATION: In all, 20 DAD patients (age = 60 ± 11 years; 12 male) (six medically managed type B AD [TBAD], 14 repaired type A AD [rTAAD] now with ascending aortic graft [AAo] or elephant trunk [ET1] repair) and 21 age-matched controls (age = 59 ± 10 years; 13 male) were included. FIELD STRENGTH/SEQUENCE: 1.5T, 3T, 4D flow MRI. ASSESSMENT: 4D flow MRI was acquired in all subjects. Data analysis included 3D segmentation of TL and FL and voxelwise calculation of forward flow, reverse flow, flow stasis, and kinetic energy as quantitative hemodynamics maps. STATISTICAL TESTS: Analysis of variance (ANOVA) or Kruskal-Wallis tests were performed for comparing subject groups. Correlation and Bland-Altman analysis was performed for the interobserver study. RESULTS: Patients with rTAAD presented with elevated TL reverse flow (AAo repair: P = 0.004, ET1: P = 0.018) and increased TL kinetic energy (AAo repair: P = 0.0002, ET1: P = 0.011) compared to controls. In addition, TL kinetic energy was increased vs. patients with TBAD (AAo repair: P = 0.021, ET1: P = 0.048). rTAAD was associated with higher FL kinetic energy and lower FL stasis compared to patients with TBAD (AAo repair: P = 0.002, ET1: P = 0.024 and AAo repair: P = 0.003, ET1: P = 0.048, respectively). DATA CONCLUSION: Quantitative maps from 4D flow MRI demonstrated global and regional hemodynamic differences between DAD patients and controls. Patients with rTAAD vs. TBAD had significantly altered regional TL and FL hemodynamics. These findings indicate the potential of 4D flow MRI-derived hemodynamic maps to help better evaluate patients with DAD. LEVEL OF EVIDENCE: 3 Technical Efficacy Stage: 1 J. Magn. Reson. Imaging 2020;51:1357-1368.

Mitral regurgitation in patients undergoing transcatheter aortic valve implantation for degenerated surgical aortic bioprosthesis: Insights from PARTNER 2 Valve-in-Valve Registry.

BACKGROUND: Valve-in-valve (VIV) treatment with transcatheter aortic valve replacement (TAVR) is a viable option for patients with failing aortic bioprosthetic valves. Optimal management of those with concomitant mitral regurgitation (MR) remains undetermined. Therefore, we sought to assess the implications of concomitant MR in patients undergoing VIV-TAVR. METHODS AND RESULTS: The PARTNER 2 VIV registry enrolled patients with degenerated surgical aortic bioprosthesis at high risk for reoperation. Patients with core-laboratory echocardiographic assessment of MR were analyzed; severe MR was excluded. We compared patients with ≤mild MR versus moderate MR and assessed changes in MR severity and clinical outcomes. A total of 339 patients (89 initial registry, 250 continued access) underwent VIV procedures; mean age 79.0 ± 10.2 years, mean Society of Thoracic Surgeon score 8.9 ± 4.5%. At baseline, 228/339 (67.3%) had ≤mild MR and 111/339 (32.7%) had moderate MR. In paired analysis, there was significant improvement in ≥moderate MR from baseline to 30 days (32.6% vs. 14.5%, p < .0001 [n = 304]), and no significant change between 30 days and 1 year (13.4% vs. 12.1%, p = .56 [n = 224]) or 1 year and 2 years (11.0% vs. 10.4%, p = .81 [n = 182]). There was no difference in death or stroke between ≤mild MR and moderate MR at 30 days (4.0% vs. 7.2%, p = .20), 1 year (15.5% vs. 15.3%, p = .98) or 2 years (26.5% vs. 23.5%, p = .67). CONCLUSION: Moderate concomitant MR tends to improve with VIV-TAVR, and was not a predictor of long-term adverse outcomes in this cohort. In selected patients undergoing VIV-TAVR, it may be appropriate to conservatively manage concomitant MR. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT# 03225001.

Seismocardiography and 4D flow MRI reveal impact of aortic valve replacement on chest acceleration and aortic hemodynamics.

Aortic valve replacement (AVR) is a common treatment for severe aortic valve disease, which can adversely affect blood flow in the aorta. Seismocardiography (SCG) measures physical vibrations at the exterior of the chest, which can be sensitive to altered cardiac function and flow dynamics. Magnetic resonance imaging (MRI) can image blood movement, and it can provide depiction and quantification of aortic flow. Here we present SCG and MRI measurements from before and after AVR and ascending aorta replacement, in the case of a woman with bicuspid aortic valve disease and a dilated ascending aorta. SCG measurements show elevated energy during systole indicating stenotic flow before surgery and lowered systolic energy levels after replacement with a prosthetic valve. MRI shows jetting, helical flow before surgery, and cohesive flow after.

Conduction recovery following pacemaker implantation after transcatheter aortic valve replacement.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) is increasingly used to treat severe aortic stenosis. A frequent complication of TAVR is high-grade or complete atrioventricular (AV) block requiring a permanent pacemaker (PPM). There are little data on the long-term dependency on pacing after TAVR. The objective of this study was to determine the proportion of patients receiving a PPM for high-grade or complete AV block after TAVR who remain dependent on the PPM in follow-up and to determine any risk factors for, particularly the effect of postballoon dilation (PBD) on, pacemaker dependency. METHODS: Of 594 consecutive patients without prior PPM undergoing TAVR (81.9% balloon-expandable, 18.1% self-expandable valve), 67 (13.1%) received a PPM after TAVR. PPM dependency was defined as AV block with a ventricular escape rate of ≤ 40 beats/min. Patient and procedural characteristics were examined according to PPM dependency status. RESULTS: Of the 67 patients who received a PPM within 10 days after TAVR, 27/67 (40.3%) were dependent at first follow-up and only 9/41 (21.9%) at 1 year. PPM dependency was more common after a self-expanding valve (76.9% vs 31.5%, P < 0.01), in those who underwent PBD (66.7% vs 24.4%, P < 0.01), and in patients in persistent complete AV block at PPM implantation (62.5% vs 7.4%, P < 0.01). CONCLUSIONS: Fewer than half of patients who receive a new PPM following TAVR are pacemaker dependent at early follow-up (< 30 days). The use of self-expanding valves and PBD are associated with a markedly increased risk of PPM dependency.

The incidence and prognostic implications of worsening right ventricular function after surgical or transcatheter aortic valve replacement: insights from PARTNER IIA.

Aims: In patients randomized to transcatheter or surgical aortic valve replacement (TAVR, SAVR), we sought to determine whether SAVR is associated with worsening right ventricular (RV) function and whether RV deterioration is associated with mortality. Methods and results: In 1376 patients from PARTNERIIA with paired baseline and 30-day core lab echocardiograms, worsening RV function was defined as decline by at least one grade from baseline to 30 days. Our primary outcome was all-cause mortality from 30 days to 2 years. Among 744 patients with TAVR, 62 (8.3%) had worsening RV function, compared with 156 of 632 patients with SAVR (24.7%) (P < 0.0001). In a multivariable model, SAVR [odds ratio (OR) 4.05, 95% confidence interval (CI) 2.55-6.44], a dilated RV (OR 2.38, 95% CI 1.37-4.14), and more than mild tricuspid regurgitation (TR) (OR 2.58, 95% CI 1.25-5.33) were associated with worsening RV function. There were 169 deaths, and patients with worsening RV function had higher all-cause mortality [hazard ratio (HR) 1.98, 95% CI 1.40-2.79]. This association remained robust after adjusting for clinical and echocardiographic variables. Among patients with worsening RV function, there was no mortality difference between TAVR and SAVR (HR 1.16, 95% CI 0.61-2.18). The development of moderate or severe RV dysfunction from baseline normal RV function conferred the worst prognosis (HR 2.87, 95% CI 1.40-5.89). Conclusion: After aortic valve replacement, worsening RV function is more common in patients with baseline RV dilation, more than mild TR, and in patients treated with SAVR. Worsening RV function and the magnitude of deterioration have important prognostic implications.

What Is Aortic Dissection?

This JAMA Patient Page describes aortic dissection, a tear in the aorta, and how it is diagnosed and treated.

Association Between Left Atrial Appendage Occlusion and Readmission for Thromboembolism Among Patients With Atrial Fibrillation Undergoing Concomitant Cardiac Surgery.

Importance: The left atrial appendage is a key site of thrombus formation in atrial fibrillation (AF) and can be occluded or removed at the time of cardiac surgery. There is limited evidence regarding the effectiveness of surgical left atrial appendage occlusion (S-LAAO) for reducing the risk of thromboembolism. Objective: To evaluate the association of S-LAAO vs no receipt of S-LAAO with the risk of thromboembolism among older patients undergoing cardiac surgery. Design, Setting, and Participants: Retrospective cohort study of a nationally representative Medicare-linked cohort from the Society of Thoracic Surgeons Adult Cardiac Surgery Database (2011-2012). Patients aged 65 years and older with AF undergoing cardiac surgery (coronary artery bypass grafting [CABG], mitral valve surgery with or without CABG, or aortic valve surgery with or without CABG) with and without concomitant S-LAAO were followed up until December 31, 2014. Exposures: S-LAAO vs no S-LAAO. Main Outcomes and Measures: The primary outcome was readmission for thromboembolism (stroke, transient ischemic attack, or systemic embolism) at up to 3 years of follow-up, as defined by Medicare claims data. Secondary end points included hemorrhagic stroke, all-cause mortality, and a composite end point (thromboembolism, hemorrhagic stroke, or all-cause mortality). Results: Among 10 524 patients undergoing surgery (median age, 76 years; 39% female; median CHA2DS2-VASc score, 4), 3892 (37%) underwent S-LAAO. Overall, at a mean follow-up of 2.6 years, thromboembolism occurred in 5.4%, hemorrhagic stroke in 0.9%, all-cause mortality in 21.5%, and the composite end point in 25.7%. S-LAAO, compared with no S-LAAO, was associated with lower unadjusted rates of thromboembolism (4.2% vs 6.2%), all-cause mortality (17.3% vs 23.9%), and the composite end point (20.5% vs 28.7%) but no significant difference in rates of hemorrhagic stroke (0.9% vs 0.9%). After inverse probability-weighted adjustment, S-LAAO was associated with a significantly lower rate of thromboembolism (subdistribution hazard ratio [HR], 0.67; 95% CI, 0.56-0.81; P < .001), all-cause mortality (HR, 0.88; 95% CI, 0.79-0.97; P = .001), and the composite end point (HR, 0.83; 95% CI, 0.76-0.91; P < .001) but not hemorrhagic stroke (subdistribution HR, 0.84; 95% CI, 0.53-1.32; P = .44). S-LAAO, compared with no S-LAAO, was associated with a lower risk of thromboembolism among patients discharged without anticoagulation (unadjusted rate, 4.2% vs 6.0%; adjusted subdistribution HR, 0.26; 95% CI, 0.17-0.40; P < .001), but not among patients discharged with anticoagulation (unadjusted rate, 4.1% vs 6.3%; adjusted subdistribution HR, 0.88; 95% CI, 0.56-1.39; P = .59). Conclusions and Relevance: Among older patients with AF undergoing concomitant cardiac surgery, S-LAAO, compared with no S-LAAO, was associated with a lower risk of readmission for thromboembolism over 3 years. These findings support the use of S-LAAO, but randomized trials are necessary to provide definitive evidence.