Outcomes of atrial fibrillation ablation in community hospitals with and without onsite cardiothoracic surgery availability

BACKGROUND

Limited data exist on outcomes of atrial fibrillation (AF) catheter ablation based on hospital setting and, specifically, the availability of onsite cardiothoracic surgery (CTS). We aimed to describe the characteristics and outcomes of catheter ablation for AF performed at a facility with and without CTS.

METHODS

This was a retrospective study of consecutive patients who underwent catheter ablation for AF at hospital with (CTS) and without cardiothoracic surgery (N-CTS) from January 2011 through December 2019. Clinical and procedural characteristics, complications, and 1-year outcomes, including clinical events and AF recurrence, were collected.

RESULTS

There were 326 unique patients who underwent an index AF ablation procedure: 206 CTS patients and 120 N-CTS patients. There were no differences in overall cardiac complications (2.5% vs. 5.8%), including mapping catheter entrapment requiring open-heart surgery (0% vs. 0.5%), pericardial effusion requiring pericardiocentesis (0.8% vs. 0.5%), hemopericardium (1.7% vs. 0.5%), acute myocardial infarction (0% vs. 1.0%), and sinus node injury (0% versus 0.5%) (all P values > .05) between N-CTS and CTS patients. Likewise, overall noncardiac complications (20.7% vs. 19.8%, P = .85), including bleeding, cerebrovascular accident, and phrenic or vagus nerve injury, were similar between N-CTS and CTS hospitals. Also, 1-year cumulative Kaplan-Meier estimates of overall AF recurrence (11.6% vs. 16.4%; log-rank P = 0.21; HR 1.47; 95% CI, 0.79-2.74) were not statistically significant between N-CTS and CTS hospitals.

CONCLUSION

Catheter ablation procedure is safe and effective regardless of onsite CTS presence, and there were no significant differences between the two hospital settings.

First Constraints on the Epoch of Reionization Using the Non-Gaussianity of the Kinematic Sunyaev-Zel'dovich Effect from the South Pole Telescope and Herschel-SPIRE Observations

We report results from an analysis aimed at detecting the trispectrum of the kinematic Sunyaev-Zel'dovich (kSZ) effect by combining data from the South Pole Telescope (SPT) and Herschel-SPIRE experiments over a 100  deg^{2} field. The SPT observations combine data from the previous and current surveys, namely SPTpol and SPT-3G, to achieve depths of 4.5, 3, and 16  μK-arcmin in bands centered at 95, 150, and 220 GHz. For SPIRE, we include data from the 600 and 857 GHz bands. We reconstruct the velocity-induced large-scale correlation of the small-scale kSZ signal with a quadratic estimator that uses two cosmic microwave background (CMB) temperature maps, constructed by optimally combining data from all the frequency bands. We reject the null hypothesis of a zero trispectrum at 10.3σ level. However, the measured trispectrum contains contributions from both the kSZ and other undesired components, such as CMB lensing and astrophysical foregrounds, with kSZ being sub-dominant. We use the agora simulations to estimate the expected signal from CMB lensing and astrophysical foregrounds. After accounting for the contributions from CMB lensing and foreground signals, we do not detect an excess kSZ-only trispectrum and use this nondetection to set constraints on reionization. By applying a prior based on observations of the Gunn-Peterson trough, we obtain an upper limit on the duration of reionization of Δz_{re,50}<4.5 (95% confidence level). We find these constraints are fairly robust to foregrounds assumptions. This trispectrum measurement is independent of, but consistent with, Planck's optical depth measurement. This result is the first constraint on the epoch of reionization using the non-Gaussian nature of the kSZ signal.

Transgender Women Exhibit a Distinct Stress Echocardiography Profile Compared With Age-Matched Cisgender Counterparts: The Mayo Clinic Women's Heart Clinic Experience

BACKGROUND

Stress echocardiographic (SE) testing is an important modality in cardiovascular risk stratification and obstructive coronary artery disease assessment. Binary sex-based parameters are classically used for the interpretation of these studies, even among transgender women (TGW). Coronary artery disease is a leading cause of morbidity and mortality in this population. Yet, it remains unclear whether TGW exhibit a distinct stress testing profile from their cisgender counterparts.

METHODS

Using a matched case-control study design, the authors compared the echocardiographic stress testing profiles of TGW (n = 43) with those of matched cisgender men (CGM; n = 84) and cisgender women (CGW; n = 86) at a single center. Relevant data, including demographics, comorbidities, and cardiac testing data, were manually extracted from the patients' charts.

RESULTS

The prevalence of hypertension and dyslipidemia was similar between TGW and CGW and lower than that of CGM (P = .003 and P = .009, respectively). The majority of comorbidities and laboratory values were similar. On average, TGW had higher heart rates than CGM (P = .002) and had lower blood pressures than CGM and CGW (P < .05). TGW's double product and metabolic equivalents were similar to those among CGW and lower than those of CGM (P = .016 and P = .018, respectively). On echocardiography, left ventricular end-diastolic and end-systolic diameters among TGW were similar to those of CGW but lower than those of CGM (P = .023 and P = .018, respectively). Measures of systolic and diastolic function, except for exercise mitral valve E/e' ratio, which was lower in TGW than CGW (P = .029), were largely similar among the three groups. There was no difference in the wall motion score index, and therefore, no difference in the percentage of positive SE test results.

CONCLUSIONS

This study shows, for the first time, that TGW have a SE profile that is distinct from that of their cisgender counterparts. Larger, multicenter, prospective studies are warranted to further characterize the SE profile of TGW.

Utilizing median and maximum QTc values improves prediction of breakthrough cardiac events in pediatric long QT syndrome

INTRODUCTION

Although prior studies indicate that a QTc > 500 ms on a single baseline 12-lead electrocardiogram (ECG) is associated with significantly increased risk of arrhythmic events in long QT syndrome (LQTS), less is known about the risk of persistent QT prolongation. We sought to determine QTc persistence and its prognostic effect on breakthrough cardiac events (BCEs) among pediatric patients treated for LQTS.

METHODS

We performed a retrospective analysis of 433 patients with LQTS evaluated, risk-stratified, and undergoing active guideline-based LQTS treatment between 1999 and 2019. BCEs were defined as arrhythmogenic syncope/seizure, sudden cardiac arrest (SCA), appropriate VF-terminating ICD shock, and sudden cardiac death (SCD).

RESULTS

During the median follow-up of 5.5 years (interquartile range [IQR] = 3-9), 32 (7%) patients experienced a total of 129 BCEs. A maximum QTc threshold of 520 ms and median QTc threshold of 490 ms were determined to be strong predictors for BCEs. A landmark analysis controlling for age, sex, genotype, and symptomatic status demonstrated models utilizing both the median QTc and maximum QTc demonstrated the highest discriminatory value (c-statistic = 0.93-0.95). Patients in the high-risk group (median QTc > 490 ms and maximum QTc > 520 ms) had a significantly lower BCE free survival (70%-81%) when compared to patients in both medium-risk (93%-97%) and low-risk (98%-99%) groups.

CONCLUSIONS

The risk of BCE among patients treated for LQTS increases not only based upon their maximum QTc, but also their median QTc (persistence of QTc prolongation). Patients with a maximum QTc > 520 ms and median QTc > 490 ms over serial 12-lead ECGs are at the highest risk of BCE while on guideline-directed medical therapy.

Outcomes of surgical septal myectomy for obstructive hypertrophic cardiomyopathy after previous septal reduction therapy

OBJECTIVE

To compare early and late outcomes of septal myectomy in patients with obstructive hypertrophic cardiomyopathy who presented with residual or recurrent left ventricular outflow tract (LVOT) obstruction after previous septal-reduction therapy (SRT).

METHODS

From January 1989 to March 2022, 145 patients underwent reintervention by septal myectomy for residual LVOT obstruction after previous SRT; 72 patients had previous alcohol septal ablation (ASA) and 73 had previous surgical septal myectomy. Baseline patient characteristics, echocardiographic parameters, and surgical outcomes were compared between these 2 groups.

RESULTS

Patients who had previous ASA were more likely to be male (50.0% vs 30.1%; P = .015), be older (median age 57.5 years vs 48.3 years; P < .001), and have a greater body mass index (32.7 kg/m2 vs 30.0 kg/m2; P = .011). After repeat SRT by septal myectomy, there was no significant difference in the incidence of postoperative complete heart block, necessitating permanent pacemaker, between the 2 groups (8.3% vs 2.7%; P = .151). One (0.7%) patient died within 30 days of surgery. Over a median follow-up of 7.5 years (interquartile range, 3.0-13.8), there were 20 deaths. Kaplan-Meier 5-, 10-, and 15-year survival rates were 100%, 91%, and 76% for the previous septal myectomy group, and 93%, 81%, and 64% for the previous ASA group (P = .207).

CONCLUSIONS

Septal myectomy for residual or recurrent LVOT obstruction in patients who had previous ASA is safe, with an acceptably low rate of postoperative complete heart block. Surgical outcomes and late survival rates in patients with complete heart block ASA were satisfactory and comparable with patients who underwent repeat myectomy.

Analysis of Anemia, Transfusions, and CABG Outcomes in The Society of Thoracic Surgeons National Database

BACKGROUND

This study characterized the association of preoperative anemia and intraoperative red blood cell (RBC) transfusion on outcomes of elective coronary artery bypass grafting (CABG).

METHODS

Data from 53,856 patients who underwent CABG included in The Society of Thoracic Surgeons (STS) Adult Cardiac Database in 2019 were used. The primary outcome was operative mortality. Secondary outcomes were postoperative complications. The association of anemia with outcomes was analyzed with multivariable regression models. The influence of intraoperative RBC transfusion on the effect of preoperative anemia on outcomes was studied using mediation analysis.

RESULTS

Anemia was present in 25% of patients. Anemic patients had a higher STS Predicted Risk of Operative Mortality (1.2% vs 0.7%; P < .001). Anemia was associated with operative mortality (odds ratio [OR], 1.27; 99.5% CI, 1.00-1.61; P = .047), postoperative RBC transfusion (OR, 2.28; 99.5% CI, 2.12-2.44; P < .001), dialysis (OR, 1.58; 99.5% CI, 1.19-2.11; P < .001), and prolonged intensive care unit and hospital length of stay. Intraoperative RBC transfusion largely mediated the effects of anemia on mortality (76%), intensive care unit stay (99%), and hospital stay, but it only partially mediated the association with dialysis (34.9%).

CONCLUSIONS

Preoperative anemia is common in patients who undergo CABG and is associated with increased postoperative risks of mortality, complications, and RBC transfusion. However, most of the effect of anemia on mortality is mediated through intraoperative RBC transfusion.

Prevalence and Prognostic Implications of Pulmonary Hypertension in Patients With Severe Aortic Regurgitation

Background

Pulmonary hypertension (PH) has been shown to be associated with worse outcomes in patients with aortic regurgitation (AR) in small older studies.

Objectives

The authors sought to evaluate the prevalence of PH in patients with severe AR, its impact on mortality and symptoms, and regression after aortic valve replacement (AVR).

Methods

A total of 821 consecutive patients with chronic ≥ moderate-severe AR on echocardiography from 2004 to 2019 were retrospectively analyzed. PH was defined as right ventricular systolic pressure (RVSP) >40 mm Hg on transthoracic echocardiogram (mild-moderate PH: RVSP 40-59 mm Hg, severe PH: RVSP > 60 mm Hg). Clinical and echocardiographic data were extracted from the electronic medical record and echocardiographic reports. The diastolic function and filling pressures were manually assessed and checked, and the left ventricular (LV) volumes were traced by a level 3-trained echocardiographer. The primary objectives were prevalence of PH in patients with ≥ moderate-severe AR, its risk associations and impact on all-cause mortality as the primary outcome. Secondary outcomes were impact of PH on symptoms and change in RVSP at discharge post-AVR. Logistic and Cox proportional hazards regression were used to analyze these outcomes.

Results

The mean age was 61.2 ± 17 years, and 162 (20%) were women. Mild-moderate PH was present in 91 (11%) patients and severe PH in 27 (3%). Larger LV size, elevated LV filling pressures, and ≥ moderate tricuspid regurgitation were associated with PH. During follow-up of 7.3 (6.3-7.9) years, 188 patients died. Compared to those without PH, risk of mortality was higher in mild-moderate PH (adjusted HR: 1.59 (95% CI: 1.07-2.36) (P = 0.021)) and severe PH (adjusted HR: 2.90 (95% CI: 1.63-5.15) (P < 0.001)). Symptoms were also more prevalent in those with PH (P = 0.004). Of 396 patients who underwent AVR during the study period, 57 had PH. AVR similarly improved survival in patients without and with PH (P for interaction = 0.23), and there was regression in RVSP (≥8 mm Hg drop) at discharge post-AVR in 35/57 (61%) patients with PH.

Conclusions

PH was present in 14% of patients with AR and was associated with higher mortality and symptoms. The survival benefit of AVR was similar in patients without and with PH.

Prosthesis choice for tricuspid valve replacement: Comparison of clinical and echocardiographic outcomes

OBJECTIVES

There is limited evidence evaluating valve function and right heart remodeling after tricuspid valve replacement (TVR), as well as whether the choice of prosthesis has an impact on these outcomes.

METHODS

We reviewed 1043 consecutive adult patients who underwent first-time TVR; 33% had previous aortic and/or mitral valve operations. Severe tricuspid valve regurgitation (TR) was the indication for surgery in 94% patients. A mechanical valve was used in 149 (14%) patients and a bioprosthetic valve in 894 (86%). Concomitant major cardiac procedures were performed in 57% of patients.

RESULTS

The median age of the cohort was 68.8 (range, 25-94) years, and 57% were female. Overall survival at 5 and 10 years was 50% and 31%, respectively. Adjusted survival and cumulative incidence of reoperation after TVR were similar in patients with bioprosthetic and mechanical valves. Overall, right ventricular (RV) function and dilation improved postoperatively with the estimated proportion of patients with moderate or greater RV systolic dysfunction/dilatation decreasing by around 20% at 3 years follow-up. After adjusting for preoperative degree of dysfunction/dilatation, valve type had no effect on late improvement in RV function and dilation. Bioprosthetic TVR was associated with greater rates of recurrence of moderate or greater TR over late follow-up. Overall, a slight decline in tricuspid valve gradients was observed over time.

CONCLUSIONS

Mechanical and bioprosthetic valves provide comparable survival, incidence of reoperation, and recovery of RV systolic function and size after TVR. Bioprosthetic valves develop significant TR over time, and mechanical valves may have an advantage for younger patients and those needing anticoagulation.

The Simons Observatory: Cryogenic half wave plate rotation mechanism for the small aperture telescopes

We present the requirements, design, and evaluation of the cryogenic continuously rotating half-wave plate (CHWP) for the Simons Observatory (SO). SO is a cosmic microwave background polarization experiment at Parque Astronómico de Atacama in northern Chile that covers a wide range of angular scales using both small (⌀0.42 m) and large (⌀6 m) aperture telescopes. In particular, the small aperture telescopes (SATs) focus on large angular scales for primordial B-mode polarization. To this end, the SATs employ a CHWP to modulate the polarization of the incident light at 8 Hz, suppressing atmospheric 1/f noise and mitigating systematic uncertainties that would otherwise arise due to the differential response of detectors sensitive to orthogonal polarizations. The CHWP consists of a 505 mm diameter achromatic sapphire HWP and a cryogenic rotation mechanism, both of which are cooled down to ∼50 K to reduce detector thermal loading. Under normal operation, the HWP is suspended by a superconducting magnetic bearing and rotates with a constant 2 Hz frequency, controlled by an electromagnetic synchronous motor. We find that the number of superconductors and the number of magnets that make up the superconducting magnetic bearing are important design parameters, especially for the rotation mechanism's vibration performance. The rotation angle is detected through an angular encoder with a noise level of 0.07 μrad s. During a cooldown process, the rotor is held in place by a grip-and-release mechanism that serves as both an alignment device and a thermal path. In this paper, we provide an overview of the SO SAT CHWP: its requirements, hardware design, and laboratory performance.

Prevalence, sex differences, and implications of pulmonary hypertension in patients with apical hypertrophic cardiomyopathy

Introduction

Apical hypertrophic cardiomyopathy (ApHCM) is a subtype of hypertrophic cardiomyopathy (HCM) that affects up to 25% of Asian patients and is not as well understood in non-Asian patients. Although ApHCM has been considered a more "benign" variant, it is associated with increased risk of atrial and ventricular arrhythmias, apical thrombi, stroke, and progressive heart failure. The occurrence of pulmonary hypertension (PH) in ApHCM, due to elevated pressures on the left side of the heart, has been documented. However, the exact prevalence of PH in ApHCM and sex differences remain uncertain.

Methods

We sought to evaluate the prevalence, risk associations, and sex differences in elevated pulmonary pressures in the largest cohort of patients with ApHCM at a single tertiary center. A total of 542 patients diagnosed with ApHCM were identified using ICD codes and clinical notes searches, confirmed by cross-referencing with cardiac MRI reports extracted through Natural Language Processing and through manual evaluation of patient charts and imaging records.

Results

In 414 patients, echocardiogram measurements of pulmonary artery systolic pressure (PASP) were obtained at the time of diagnosis. The mean age was 59.4 ± 16.6 years, with 181 (44%) being females. The mean PASP was 38 ± 12 mmHg in females vs. 33 ± 9 mmHg in males (p < 0.0001). PH as defined by a PASP value of > 36 mmHg was present in 140/414 (34%) patients, with a predominance in females [79/181 (44%)] vs. males [61/233 (26%), p < 0.0001]. Female sex, atrial fibrillation, diagnosis of congestive heart failure, and elevated filling pressures on echocardiogram remained significantly associated with PH (PASP > 36 mmHg) in multivariable modeling. PH, when present, was independently associated with mortality [hazard ratio 1.63, 95% CI (1.05-2.53), p = 0.028] and symptoms [odds ratio 2.28 (1.40, 3.71), p < 0.001].

Conclusion

PH was present in 34% of patients with ApHCM at diagnosis, with female sex predominance. PH in ApHCM was associated with symptoms and increased mortality.

Characterization of a half-wave plate for cosmic microwave background circular polarization measurement with POLARBEAR

A half-wave plate (HWP) is often used as a modulator to suppress systematic error in the measurements of cosmic microwave background (CMB) polarization. A HWP can also be used to measure circular polarization (CP) through its optical leakage from CP to linear polarization. The CP of the CMB is predicted from various sources, such as interactions in the Universe and extension of the standard model. Interaction with supernova remnants of population III stars is one of the brightest CP sources. Thus, the observation of the CP of CMB is a new tool for searching for population III stars. In this paper, we demonstrate the improved measurement of the leakage coefficient using the transmission measurement of an actual HWP in the laboratory. We measured the transmittance of linearly polarized light through the HWP used in Polarbear in the frequency range of 120-160 GHz. We evaluate the properties of the HWP by fitting the data with a physical model using the Markov Chain Monte Carlo method. We then estimate the band-averaged CP leakage coefficient using the physical model. We find that the leakage coefficient strongly depends on the spectra of CP sources. We thus calculate the maximum fractional leakage coefficient from CP to linear polarization as 0.133 ± 0.009 in the Rayleigh-Jeans spectrum. The nonzero value shows that Polarbear has a sensitivity to CP. Additionally, because we use the bandpass of detectors installed in the telescope to calculate the band-averaged values, we also consider systematic effects in the experiment.

The Interaction of FEV1 and NT-Pro-BNP with Outcomes after Transcatheter Aortic Valve Replacement

OBJECTIVES

Low forced expiratory volume in 1 second (FEV1) and elevated N-terminal Pro form B-type natriuretic peptide (NT-Pro-BNP) have been individually associated with poor outcomes after transcatheter aortic valve replacement (TAVR). We hypothesized a combination of the two would provide prognostic indication after TAVR.

METHODS

We categorized 871 patients who received TAVR from 2008 to 2018 into 4 groups according to baseline FEV1 (< or ≥ 60% predicted) and NT-Pro-BNP (< or ≥ 1601 pg/ml): group A (n = 312, high FEV1, low NT-Pro-BNP), group B (n = 275, high FEV1, high NT-Pro-BNP), group C (n = 123 low FEV1, low NT-Pro-BNP), and group D (n = 161, low FEV1, high NT-Pro-BNP). The primary endpoint was survival at 1 and 5 years.

RESULTS

Patients in group A had more severe aortic stenosis and achieved the best long-term survival at 1- (93% (95% CI: 90-96) and 5- years (45.3% (95% CI: 35.4-58). Low FEV1 and high NT-Pro-BNP (group D) patients had more severe symptoms, higher Society of Thoracic Surgeons predicted risk of operative mortality, lower ejection fraction and aortic valve gradient at baseline. They had the worst survival at 1- (76% (95% CI: 69-83) and at 5-years (13.1% (95% CI: 7-25), Hazard Ratio compared to group A: 2.29 (95% CI: 1.6-3.2, p < 0.001) with 25.7% of patients in NYHA class III-IV. Patients in groups B and C had intermediate outcomes.

CONCLUSIONS

The combination of FEV1 and NT-Pro-BNP stratify patients into 4 groups with distinct risk profiles and clinical outcomes. Patients with low FEV1 and high NT-Pro-BNP have increased comorbidities, poor functional outcomes, and decreased long term survival after TAVR.

Simulated Performance of Laser-Machined Metamaterial Anti-reflection Coatings

Lenslet-coupled antenna arrays have been used in CMB experiments and are the baseline technology for the next-generation satellite missions such as LiteBIRD and PICO. Lenslets are small hemispherical lenses mounted on the focal plane that couple light to the detectors and are typically made of silicon or alumina due to their high focusing power and low absorption loss. To minimize reflection at the vacuum-dielectric interface, lenslets require anti-reflection (AR) coatings. Metamaterials have been used in large microwave optical components because they avoid any mismatch on the thermal expansion between the lens and its coating, but so far they have only been machined on surfaces of comparatively large radius of curvature. As a first step to understand the feasibility of machining metamaterial AR layers in lenslets through laser-etching for the LiteBIRD mission, a model in ANSYS HFSS was developed. The goal of the simulation was to optimize transmission in three frequency bands while meeting assumed laser machinability constraints and optical requirements. Simulation results from flat silicon show that an AR metamaterial coating made under the assumed conditions is feasible, and the baseline parameters for further curved-surface studies are provided.

Prevalence and Natural History of Mitral Annulus Calcification and Related Valve Dysfunction

OBJECTIVE

To evaluate the prevalence and natural history of mitral annulus calcification (MAC) and associated mitral valve dysfunction (MVD) in patients undergoing clinically indicated echocardiography.

METHODS

A retrospective review was conducted of all adults who underwent echocardiography in 2015. Mitral valve dysfunction was defined as mitral regurgitation or mitral stenosis (MS) of moderate or greater severity. All-cause mortality during 3.0 (0.4 to 4.2) years of follow-up was compared between groups stratified according to the presence of MAC or MVD.

RESULTS

Of 24,414 evaluated patients, 5502 (23%) had MAC. Patients with MAC were older (75±10 years vs 60±16 years; P<.001) and more frequently had MVD (MS: 6.6% vs 0.5% [P<.001]; mitral regurgitation without MS: 9.5% vs 6.1% [P<.001]). Associated with MS in patients with MAC were aortic valve dysfunction, female sex, chest irradiation, renal dysfunction, and coronary artery disease. Kaplan-Meier 1-year survival was 76% in MAC+/MVD+, 87% in MAC+/MVD-, 86% in MAC-/MVD+, and 92% in MAC-/MVD-. Adjusted for age, diabetes, renal dysfunction, cancer, chest irradiation, ejection fraction below 50%, aortic stenosis, tricuspid regurgitation, and pulmonary hypertension, MAC was associated with higher mortality during follow-up (adjusted hazard ratio, 1.40; 95% CI, 1.31 to 1.49; P<.001); MVD was associated with even higher mortality in patients with MAC (adjusted hazard ratio, 1.79; 95% CI, 1.58 to 2.01; P<.001). There was no significant interaction between MAC and MVD for mortality (P=.10).

CONCLUSION

In a large cohort of adults undergoing echocardiography, the prevalence of MAC was 23%. Mitral valve dysfunction was more than twice as prevalent in patients with MAC. Adjusted mortality was increased in patients with MAC and worse with both MAC and MVD.

Optimal Management of Mitral Regurgitation Due to Ruptured Mitral Chordae Tendineae in Patients With Hypertrophic Cardiomyopathy

There is continued controversy regarding surgical management of patients with hypertrophic cardiomyopathy (HCM) and intrinsic mitral valve disease; some clinicians favor prosthetic replacement as this corrects left ventricular outflow tract (LVOT) obstruction and valve leakage. In this study, we investigated the management and late outcome of operation for mitral regurgitation (MR) due to ruptured chordae tendineae in patients with HCM. We analyzed 49 consecutive patients with HCM and MR due to ruptured mitral valve chordae. Echocardiograms and operative reports were reviewed to classify valve anatomy and surgical methods. Information on late outcomes was obtained from electronic medical records and follow-up surveys. The mean age of the 36 men and 13 women was 61.9 ± 12.5 years; significant resting or provoked LVOT obstruction was present at the time of surgery in 46 patients. During the index operation, mitral valve repair was performed in 45 patients, and prosthetic replacement was necessary for 4 patients. Concomitant septal myectomy was performed in 46 patients. There were no hospital deaths or deaths within 30 days of operation. Five and ten-year survival estimates (Kaplan-Meier) were 92% and 71%. During follow-up at a median of 7.9 years, 3 patients underwent reoperation for MV replacement, 5 days, 3 years, and 14 years following valve repair. Ruptured mitral chordae may result in severe mitral valve regurgitation in patients with hypertrophic cardiomyopathy. Valvuloplasty at the time of septal myectomy is safe with an acceptably low rate of recurrent MR requiring prosthetic replacement.

Incidence Trends and Epidemiology of Staphylococcus aureus Bacteremia: A Systematic Review of Population-Based Studies

OBJECTIVES

To determine incidence trends of Staphylococcus aureus bacteremia (SAB) from population-based studies from multiple countries.

METHODS

A contemporary systematic review was conducted using Ovid Cochrane Central Register of Controlled Trials (1991+), Ovid Embase (1974+), Ovid Medical Literature Analysis and Retrieval System Online (MEDLINE) (1946+ including epub ahead of print, in-process & other non-indexed citations), and Web of Science Core Collection (Science Citation Index Expanded 1975+ and Emerging Sources Citation Index 2015+). Two authors (J.R.H. and J.A.Q.M.) independently reviewed all studies and included those that reported population-based incidence of SAB in patients aged 18 years and older.

RESULTS

Twenty-six studies met inclusion criteria with the highest number (n=6) of studies conducted in Canada. The incidence of SAB ranged from 9.3 to 65 cases/100,000/year. The median age of patients with SAB ranged from 62 to 72 years and SAB cases were more commonly observed in men than in women. The most common infection sources were intravascular catheters and skin and soft tissue infections. SAB incidence trends demonstrated high variability for geographic regions and calendar years. Overall, there was no change in the incidence trend across all studies during the past two decades.

CONCLUSION

Multiple factors, both pros, and cons are likely responsible for the overall stable SAB incidence in countries included in this systematic review. Some of these factors vary in geographic location and prompt additional investigations from countries not included in the current review so that a more global characterization is defined.

Effect of Shared Decision-Making for Stroke Prevention on Treatment Adherence and Safety Outcomes in Patients With Atrial Fibrillation: A Randomized Clinical Trial

Background Guidelines promote shared decision-making (SDM) for anticoagulation in patients with atrial fibrillation. We recently showed that adding a within-encounter SDM tool to usual care (UC) increases patient involvement in decision-making and clinician satisfaction, without affecting encounter length. We aimed to estimate the extent to which use of an SDM tool changed adherence to the decided care plan and clinical safety end points. Methods and Results We conducted a multicenter, encounter-level, randomized trial assessing the efficacy of UC with versus without an SDM conversation tool for use during the clinical encounter (Anticoagulation Choice) in patients with nonvalvular atrial fibrillation considering starting or reviewing anticoagulation treatment. We conducted a chart and pharmacy review, blinded to randomization status, at 10 months after enrollment to assess primary adherence (proportion of patients who were prescribed an anticoagulant who filled their first prescription) and secondary adherence (estimated using the proportion of days for which treatment was supplied and filled for direct oral anticoagulant, and as time in therapeutic range for warfarin). We also noted any strokes, transient ischemic attacks, major bleeding, or deaths as safety end points. We enrolled 922 evaluable patient encounters (Anticoagulation Choice=463, and UC=459), of which 814 (88%) had pharmacy and clinical follow-up. We found no differences between arms in either primary adherence (78% of patients in the SDM arm filled their first prescription versus 81% in UC arm) or secondary adherence to anticoagulation (percentage days covered of the direct oral anticoagulant was 74.1% in SDM versus 71.6% in UC; time in therapeutic range for warfarin was 66.6% in SDM versus 64.4% in UC). Safety outcomes, mostly bleeds, occurred in 13% of participants in the SDM arm and 14% in the UC arm. Conclusions In this large, randomized trial comparing UC with a tool to promote SDM against UC alone, we found no significant differences between arms in primary or secondary adherence to anticoagulation or in clinical safety outcomes. Registration URL: https://www.clinicaltrials.gov; Unique identifier: clinicaltrials.gov. Identifier: NCT02905032.

Mitral Annular Calcification in Obstructive Hypertrophic Cardiomyopathy: Prevalence and Outcomes

BACKGROUND

The prevalence and clinical impact of mitral annular calcification (MAC) in patients with obstructive hypertrophic cardiomyopathy (HCM) are largely unknown.

METHODS

We reviewed 2113 HCM patients who underwent septal myectomy from January 2000 to April 2016. Preoperative and intraoperative echocardiograms along with operative notes were reviewed to identify MAC. Survival was estimated and compared using Kaplan-Meier analysis and log-rank test. Cox regression analysis was used to identify factors independently associated with mortality.

RESULTS

MAC was identified in 390 (18.5%) patients. Older age, female sex, and presence of mitral valve leaflet calcification were strongly associated with higher odds of having MAC. Patients with MAC had higher resting LVOT gradients, more likely to have worse mitral valve regurgitation (MR) preoperatively, and more likely to undergo a concomitant mitral valve replacement (6% vs 1%, P<0.001) compared to those without MAC. Postoperatively, patients with MAC had marginally higher residual MR (13% vs 8%). After a median follow-up of 6.95 (IQR 3.7- 12.1) years, survival of patients with MAC at 1, 5 and 10 years was 99%, 92% and 69% respectively. Adjusted analysis identified MAC as an independent predictor of poor survival (HR 1.46, 95% CI 1.08 to 1.97; P=.014).

CONCLUSIONS

MAC is a frequent finding in older patients with obstructive HCM, more likely to be seen in females, and is associated with higher rates of concomitant mitral valve replacement. Despite higher prevalence of comorbidities, MAC remained an independent predictor for overall mortality following septal myectomy.

The Role of Rho GTPases During Fibroblast Spreading, Migration, and Myofibroblast Differentiation in 3D Synthetic Fibrous Matrices

INTRODUCTION

Connective tissue repair and mechanosensing are tightly entwined in vivo and occur within a complex three-dimensional (3D), fibrous extracellular matrix (ECM). Typically driven by activated fibroblasts, wound repair involves well-defined steps of cell spreading, migration, proliferation, and fibrous ECM deposition. While the role of Rho GTPases in regulating these processes has been explored extensively in two-dimensional cell culture models, much less is known about their role in more physiologic, 3D environments.

METHODS

We employed a 3D, fibrous and protease-sensitive hydrogel model of interstitial ECM to study the interplay between Rho GTPases and fibrous matrix cues in fibroblasts during wound healing.

RESULTS

Modulating fiber density within protease-sensitive hydrogels, we confirmed previous findings that heightened fiber density promotes fibroblast spreading and proliferation. The presence of matrix fibers furthermore corresponded to increased cell migration speeds and macroscopic hydrogel contraction arising from fibroblast generated forces. During fibroblast spreading, Rac1 and RhoA GTPase activity proved crucial for fiber-mediated cell spreading and contact guidance along matrix fibers, while Cdc42 was dispensable. In contrast, interplay between RhoA, Rac1, and Cdc42 contributed to fiber-mediated myofibroblast differentiation and matrix contraction over longer time scales.

CONCLUSION

These observations may provide insights into tissue repair processes in vivo and motivate the incorporation of cell-adhesive fibers within synthetic hydrogels for material-guided wound repair strategies.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s12195-021-00698-5.

Artificial Intelligence-Augmented Electrocardiogram Detection of Left Ventricular Systolic Dysfunction in the General Population

OBJECTIVE

To validate an artificial intelligence-augmented electrocardiogram (AI-ECG) algorithm for the detection of preclinical left ventricular systolic dysfunction (LVSD) in a large community-based cohort.

METHODS

We identified a randomly selected community-based cohort of 2041 subjects age 45 years or older in Olmsted County, Minnesota. All participants underwent a study echocardiogram and ECG. We first assessed the performance of the AI-ECG to identify LVSD (ejection fraction ≤40%). After excluding participants with clinical heart failure, we further assessed the AI-ECG to detect preclinical LVSD among all patients (n=1996) and in a high-risk subgroup (n=1348). Next we modelled an imputed screening program for preclinical LVSD detection where a positive AI-ECG triggered an echocardiogram. Finally, we assessed the ability of the AI-ECG to predict future LVSD. Participants were enrolled between January 1, 1997, and September 30, 2000; and LVSD surveillance was performed for 10 years after enrollment.

RESULTS

For detection of LVSD in the total population (prevalence, 2.0%), the area under the receiver operating curve for AI-ECG was 0.97 (sensitivity, 90%; specificity, 92%); in the high-risk subgroup (prevalence 2.7%), the area under the curve was 0.97 (sensitivity, 92%; specificity, 93%). In an imputed screening program, identification of one preclinical LSVD case would require 88.3 AI-ECGs and 8.7 echocardiograms in the total population and 65.7 AI-ECGs and 5.5 echocardiograms in the high-risk subgroup. The unadjusted hazard ratio for a positive AI-ECG for incident LVSD over 10 years was 2.31 (95% CI, 1.32 to 4.05; P=.004).

CONCLUSION

Artificial intelligence-augmented ECG can identify preclinical LVSD in the community and warrants further study as a screening tool for preclinical LVSD.

Effectiveness of a Weight Loss Program Using Digital Health in Adolescents and Preadolescents

Objective: To identify an efficacious intervention on treating adolescents with overweight and obesity, this might result in health benefits. Methods: Adolescents with overweight or obesity aged 10-17 years with BMI percentile ≥85th were included in this historical observational analysis. Subjects used an entirely remote weight loss program combining mobile applications, frequent self-weighing, and calorie restriction with meal replacement. Body weight changes were evaluated at 42, 60, 90, and 120 days using different metrics including absolute body weight, BMI, and BMI z-score. Chi-square or Fisher exact tests (categorical variables) and Student's t-test (continuous variables) were used to compare subjects. Results: In total, 2,825 participants, mean age 14.4 ± 2.2 years, (54.8% girls), were included from October 27, 2016, to December 31, 2017, in mainland China; 1355 (48.0%) had a baseline BMI percentile ≥97th. Mean BMI and BMI z-score were 29.20 ± 4.44 kg/m2 and 1.89 ± 0.42, respectively. At day 120, mean reduction in body weight, BMI, and BMI z-score was 8.6 ± 0.63 kg, 3.13 ± 0.21 kg/m2, and 0.42 ± 0.03; 71.4% had lost ≥5% body weight, 69.4% of boys and 73.2% of girls, respectively. Compared with boys, girls achieved greater reduction on BMI z-score at all intervals (p < 0.004 for all comparisons). Higher BMI percentile at baseline and increased frequency of use of the mobile application were directly associated with more significant weight loss. Conclusions: An entirely remote digital weight loss program is effective in facilitating weight loss in adolescents with overweight or obesity in the short term and mid term.

Myocardial Histopathology in Patients With Obstructive Hypertrophic Cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is characterized by multiple pathological features including myocyte hypertrophy, myocyte disarray, and interstitial fibrosis.

OBJECTIVES

This study sought to correlate myocardial histopathology with clinical characteristics of patients with obstructive HCM and post-operative outcomes following septal myectomy.

METHODS

The authors reviewed the pathological findings of the myocardial specimens from 1,836 patients with obstructive HCM who underwent septal myectomy from 2000 to 2016. Myocyte hypertrophy, myocyte disarray, interstitial fibrosis, and endocardial thickening were graded and analyzed.

RESULTS

The median age at operation was 54.2 years (43.5 to 64.3 years), and 1,067 (58.1%) were men. A weak negative correlation between myocyte disarray and age at surgery was identified (ρ = -0.22; p < 0.001). Myocyte hypertrophy (p < 0.001), myocyte disarray (p < 0.001), and interstitial fibrosis (p < 0.001) were positively associated with implantable cardioverter-defibrillator implantation. Interstitial fibrosis (p < 0.001) and endocardial thickening (p < 0.001) were associated with atrial fibrillation pre-operatively. In the Cox survival model, older age (p < 0.001), lower degree of myocyte hypertrophy (severe vs. mild hazard ratio: 0.41; 95% confidence interval: 0.19 to 0.86; p = 0.040), and lower degree of endocardial thickening (moderate vs. mild hazard ratio: 0.75; 95% confidence interval: 0.58 to 0.97; p = 0.019) were independently associated with worse post-myectomy survival. Among 256 patients who had genotype analysis, patients with pathogenic or likely pathogenic variants (n = 62) had a greater degree of myocyte disarray (42% vs. 15% vs. 20%; p = 0.022). Notably, 13 patients with pathogenic or likely pathogenic genetic variants of HCM had no myocyte disarray.

CONCLUSIONS

Histopathology was associated with clinical manifestations including the age of disease onset and arrhythmias. Myocyte hypertrophy and endocardial thickening were negatively associated with post-myectomy mortality.