Changes in telemedicine use and ambulatory visit volumes at a multispecialty cardiovascular center during the COVID-19 pandemic

Early in the COVID-19 pandemic, cardiology clinics rapidly implemented telemedicine to maintain access to care. Little is known about subsequent trends in telemedicine use and visit volumes across cardiology subspecialties. We conducted a retrospective cohort study including all patients with ambulatory visits at a multispecialty cardiovascular center in Northern California from March 2019 to February 2020 (pre-COVID) and March 2020 to February 2021 (COVID). Telemedicine use increased from 3.5% of visits (1200/33,976) during the pre-COVID period to 63.0% (21,251/33,706) during the COVID period. Visit volumes were below pre-COVID levels from March to May 2020 but exceeded pre-COVID levels after June 2020, including when local COVID-19 cases peaked. Telemedicine use was above 75% of visits in all cardiology subspecialties in April 2020 and stabilized at rates ranging from over 95% in electrophysiology to under 25% in heart transplant and vascular medicine. From June 2020 to February 2021, subspecialties delivering a greater percentage of visits through telemedicine experienced larger increases in new patient visits (r = 0.81, p = 0.029). Telemedicine can be used to deliver a significant proportion of outpatient cardiovascular care though utilization varies across subspecialties. Higher rates of telemedicine adoption may increase access to care in cardiology clinics.

Drivers of telemedicine in primary care clinics at a large academic medical centre

BACKGROUND

COVID-19 disrupted healthcare routines and prompted rapid telemedicine implementation. We investigated the drivers of visit modality selection (telemedicine versus in-person) in primary care clinics at an academic medical centre.

METHODS

We used electronic medical record data from March 2020 to May 2022 from 13 primary care clinics (N = 21,031 new, N = 207,292 return visits), with 55% overall telemedicine use. Hierarchical logistic regression and cross-validation methods were used to estimate the variation in visit modality explained by the patient, clinician and visit factors as measured by the mean-test area under the curve (AUC).

RESULTS

There was significant variation in telemedicine use across clinicians (ranging from 0-100%) for the same visit diagnosis. The strongest predictors of telemedicine were the clinician seen for new visits (mean AUC of 0.79) and the primary visit diagnosis for return visits (0.77). Models based on all patient characteristics combined accounted for relatively little variation in modality selection, 0.54 for new and 0.58 for return visits, respectively. Amongst patient characteristics, males, patients over 65 years, Asians and patient's with non-English language preferences used less telemedicine; however, those using interpreter services used significantly more telemedicine.

CONCLUSION

Clinician seen and primary visit diagnoses were the best predictors of visit modality. The distinction between new and return visits and the minimal impact of patient characteristics on visit modality highlights the complexity of clinical care and warrants research approaches that go beyond linear models to uncover the emergent causal effects of specific technology features mediated by tasks, people and organisations.

Real-world utilization of guideline-directed genetic testing in inherited cardiovascular diseases

Background

Cardiovascular disease continues to be the leading cause of death globally. Clinical practice guidelines aimed at improving disease management and positively impacting major cardiac adverse events recommend genetic testing for inherited cardiovascular conditions such as dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), long QT syndrome (LQTS), hereditary amyloidosis, and familial hypercholesterolemia (FH); however, little is known about how consistently practitioners order genetic testing for these conditions in routine clinical practice. This study aimed to assess the adoption of guideline-directed genetic testing for patients diagnosed with DCM, HCM, LQTS, hereditary amyloidosis, or FH.

Methods

This retrospective cohort study captured real-world evidence of genetic testing from ICD-9-CM and ICD-10-CM codes, procedure codes, and structured text fields of de-identified patient records in the Veradigm Health Insights Ambulatory EHR Research Database linked with insurance claims data. Data analysis was conducted using an automated electronic health record analysis engine. Patient records in the Veradigm database were sourced from more than 250,000 clinicians serving over 170 million patients in outpatient primary care and specialty practice settings in the United States and linked insurance claims data from public and private insurance providers. The primary outcome measure was evidence of genetic testing within six months of condition diagnosis.

Results

Between January 1, 2017, and December 31, 2021, 224,641 patients were newly diagnosed with DCM, HCM, LQTS, hereditary amyloidosis, or FH and included in this study. Substantial genetic testing care gaps were identified. Only a small percentage of patients newly diagnosed with DCM (827/101,919; 0.8%), HCM (253/15,507; 1.6%), LQTS (650/56,539; 1.2%), hereditary amyloidosis (62/1,026; 6.0%), or FH (718/49,650; 1.5%) received genetic testing.

Conclusions

Genetic testing is underutilized across multiple inherited cardiovascular conditions. This real-world data analysis provides insights into the delivery of genomic healthcare in the United States and suggests genetic testing guidelines are rarely followed in practice.

Sociodemographic disparities in the use of cardiovascular ambulatory care and telemedicine during the COVID-19 pandemic

BACKGROUND

The COVID-19 pandemic accelerated adoption of telemedicine in cardiology clinics. Early in the pandemic, there were sociodemographic disparities in telemedicine use. It is unknown if these disparities persisted and whether they were associated with changes in the population of patients accessing care.

METHODS

We examined all adult cardiology visits at an academic and an affiliated community practice in Northern California from March 2019 to February 2020 (pre-COVID) and March 2020 to February 2021 (COVID). We compared patient sociodemographic characteristics between these periods. We used logistic regression to assess the association of patient/visit characteristics with visit modality (in-person vs telemedicine and video- vs phone-based telemedicine) during the COVID period.

RESULTS

There were 54,948 pre-COVID and 58,940 COVID visits. Telemedicine use increased from <1% to 70.7% of visits (49.7% video, 21.0% phone) during the COVID period. Patient sociodemographic characteristics were similar during both periods. In adjusted analyses, visits for patients from some sociodemographic groups were less likely to be delivered by telemedicine, and when delivered by telemedicine, were less likely to be delivered by video versus phone. The observed disparities in the use of video-based telemedicine were greatest for patients aged ≥80 years (vs age <60, OR 0.24, 95% CI 0.21, 0.28), Black patients (vs non-Hispanic White, OR 0.64, 95% CI 0.56, 0.74), patients with limited English proficiency (vs English proficient, OR 0.52, 95% CI 0.46-0.59), and those on Medicaid (vs privately insured, OR 0.47, 95% CI 0.41-0.54).

CONCLUSIONS

During the first year of the pandemic, the sociodemographic characteristics of patients receiving cardiovascular care remained stable, but the modality of care diverged across groups. There were differences in the use of telemedicine vs in-person care and most notably in the use of video- vs phone-based telemedicine. Future studies should examine barriers and outcomes in digital healthcare access across diverse patient groups.

Clinical programs for cardiometabolic health for South Asian patients in the United States: A review of key program components

Medical literature shows that South Asians have approximately a 2-fold higher risk of atherosclerotic cardiovascular disease (CVD) compared with other populations. Given this high prevalence, clinical programs to promote cardiovascular health have emerged in the United States that are dedicated to clinical care for South Asian individuals. In this review, we have summarized the key characteristics of clinical programs in the U.S. dedicated to preventing and managing CVD in South Asian American patients. These clinical centers have many unique components in common that are catered to South Asian patient populations including ethnicity concordance of clinical providers, intensive cardiovascular screening protocols with laboratory studies and potentially genetic testing, dieticians and nutritionists who are familiar with South Asian-style dietary patterns, health coaches to support behavior change, community outreach programs, and involvement in clinical research to learn further about risk factors, prevention, and treatment of cardiovascular disease in South Asian populations. There are still many evidence and programmatic gaps left to uncover in the prevention, diagnosis, and management of CVD in South Asian. This review provides guidance for important features, barriers, and facilitators for future cardiovascular centers to develop in the United States where they can serve South Asian populations.

Abstract P372: Drivers of Visit Modality in Primary Care Clinics at an Academic Medical Center

Background: Informed by drivers of visit modality in specialty clinics, we sought to identify factors associated with visit modality selection (telemedicine vs. in-person) for new and return visits in primary care clinics at a large academic medical center (AMC).

Methods: We used electronic health record data from 3/2020 - 5/2022 from 13 primary care clinics with 98 unique clinicians for new and 131 for return visits (21,031 new & 207,292 return visits), with about 55% telemedicine (telephone and video) use. We used hierarchical logistic regression and cross-validation methods to estimate the variation in visit modality associated with the patient, clinician, and visit factors (measured with Area Under the Curve).

Results: For both new and return visits, there was significant variation in telemedicine use among clinicians (ranging from 0 - 100%) for specific clinical diagnoses (Figure 1). Most variation in telemedicine use was attributed to the clinician seen (new visits) and primary visit diagnosis (return visits). Other visit and patient characteristics were less predictive. For new visits, the clinician model had an AUC of 0.79, followed by clinic site 0.69, whereas for return visits, the primary diagnosis was 0.77, followed by the clinician seen at 0.65. Diagnoses most commonly seen via telemedicine include acute respiratory infection and suspected COVID-19 exposure. Diagnoses commonly seen in-person include annual physical and gynecological exams.

Conclusions: Our findings show high variability in telemedicine use for the same diagnosis and differential drivers of visit modality between new and return visits in primary care clinics at a large AMC. Provider ID was the most predictive factor of visit modality for new patients, indicating that clinician preference and individual practice patterns influence the modality of care much more than patient preference. Primary care clinics may reduce the variability in visit modality through standardized processes that integrate clinical factors and patient preference.

Abstract P224: The Collaborative, Iterative Process of Changing Diet Toward Plant Proteins: A Qualitative Study Exploring the Drivers and Process of Dietary Change

Background: Psychological models describe dietary change as linear, self-regulatory, and outcome driven. Yet, the average adult tries at least two diets a year and abandons them after a few days. The cardiometabolic benefits of plant proteins (PP) are undisputed, but changing protein choices can be challenging.

Methods: We recruited 30 adults who changed their protein choice using snowball sampling and conducted inductive semi-structured interviews to understand why and how protein choices shift, who influences them, and whether they stick. Participants shared influencer names, the extent of influence (high-3, medium-2, low-1), and their rationale regarding food decisions. We transcribed and analyzed the interviews to identify common themes and mapped their social network.

Results: (90%) 27/30 identified at least two PP sources, (33%) 10/30 entirely replaced animal protein (AP) with PP, (57%) 17/30 decreased AP intake significantly but did not replace it with PP, (10%) 3/30 increased AP sources. All reported continuing change for at least six months. Our analysis, Figure 1, uncovers a mindful process of change that is collaborative, continuous, iterative, and adaptive, anchored in three dimensions: 1) Crafting the milieu - personal and social environment: 2) Discovering social self - cultivating psychosocial awareness thru practice and reflection: and 3) Sociotechnical art - acquiring culinary knowledge from others. Social network analysis (SNA) revealed three boundary spanners connecting more than one group, betweenness (>0.4), three popular participants, eigencentrality (>0.5) and many community formations, modularity (0.82), Figure 2.

Conclusion: Based on our results, people who desire change gravitate toward those who have successfully navigated it. The process of dietary change reveals opportunities to tailor diets supporting close family and connections. Identifying and targeting diet recommendations towards influencers in local communities may help achieve widespread and long-lasting change.

Sociodemographic Determinants of Oral Anticoagulant Prescription in Patients with Atrial Fibrillations: Findings from the PINNACLE Registry Using Machine Learning

Background

Current risk scores that are solely based on clinical factors have shown modest predictive ability for understanding of factors associated with gaps in real-world prescription of oral anticoagulation (OAC) in patients with atrial fibrillation (AF).

Objective

In this study, we sought to identify the role of social and geographic determinants, beyond clinical factors associated with variation in OAC prescriptions using a large national registry of ambulatory patients with AF.

Methods

Between January 2017 and June 2018, we identified patients with AF from the American College of Cardiology PINNACLE (Practice Innovation and Clinical Excellence) Registry. We examined associations between patient and site-of-care factors and prescription of OAC across U.S. counties. Several machine learning (ML) methods were used to identify factors associated with OAC prescription.

Results

Among 864,339 patients with AF, 586,560 (68%) were prescribed OAC. County OAC prescription rates ranged from 26.8% to 93%, with higher OAC use in the Western United States. Supervised ML analysis in predicting likelihood of OAC prescriptions and identified a rank order of patient features associated with OAC prescription. In the ML models, in addition to clinical factors, medication use (aspirin, antihypertensives, antiarrhythmic agents, lipid modifying agents), and age, household income, clinic size, and U.S. region were among the most important predictors of an OAC prescription.

Conclusion

In a contemporary, national cohort of patients with AF underuse of OAC remains high, with notable geographic variation. Our results demonstrated the role of several important demographic and socioeconomic factors in underutilization of OAC in patients with AF.

Drivers of variation in telemedicine use during the COVID-19 pandemic: The experience of a large academic cardiovascular practice

BACKGROUND

COVID-19 spurred rapid adoption and expansion of telemedicine. We investigated the factors driving visit modality (telemedicine vs. in-person) for outpatient visits at a large cardiovascular center.

METHODS

We used electronic health record data from March 2020 to February 2021 from four cardiology subspecialties (general cardiology, electrophysiology, heart failure, and interventional cardiology) at a large academic health system in Northern California. There were 21,912 new and return visits with 69% delivered by telemedicine. We used hierarchical logistic regression and cross-validation methods to estimate the variation in visit modality explained by patient, clinician, and visit factors as measured by the mean area under the curve.

RESULTS

Across all subspecialties, the clinician seen was the strongest predictor of telemedicine usage, while primary visit diagnosis was the next most predictive. In general cardiology, the model based on clinician seen had a mean area under the curve of 0.83, the model based on the primary diagnosis had a mean area under the curve of 0.69, and the model based on all patient characteristics combined had a mean area under the curve of 0.56. There was significant variation in telemedicine use across clinicians within each subspecialty, even for visits with the same primary visit diagnosis.

CONCLUSION

Individual clinician practice patterns had the largest influence on visit modality across subspecialties in a large cardiovascular medicine practice, while primary diagnosis was less predictive, and patient characteristics even less so. Cardiovascular clinics should reduce variability in visit modality selection through standardized processes that integrate clinical factors and patient preference.

Pandemic-proof recruitment and engagement in a fully decentralized trial in atrial fibrillation patients (DeTAP)

The Coronavirus Disease 2019 (COVID-19) pandemic curtailed clinical trial activity. Decentralized clinical trials (DCTs) can expand trial access and reduce exposure risk but their feasibility remains uncertain. We evaluated DCT feasibility for atrial fibrillation (AF) patients on oral anticoagulation (OAC). DeTAP (Decentralized Trial in Afib Patients, NCT04471623) was a 6-month, single-arm, 100% virtual study of 100 AF patients on OAC aged >55 years, recruited traditionally and through social media. Participants enrolled and participated virtually using a mobile application and remote blood pressure (BP) and six-lead electrocardiogram (ECG) sensors. Four engagement-based primary endpoints included changes in pre- versus end-of-study OAC adherence (OACA), and % completion of televisits, surveys, and ECG and BP measurements. Secondary endpoints included survey-based nuisance bleeding and patient feedback. 100 subjects (mean age 70 years, 44% women, 90% White) were recruited in 28 days (traditional: 6 pts; social media: 94 pts in 12 days with >300 waitlisted). Study engagement was high: 91% televisits, 85% surveys, and 99% ECG and 99% BP measurement completion. OACA was unchanged at 6 months (baseline: 97 ± 9%, 6 months: 96 ± 15%, p = 0.39). In patients with low baseline OACA (<90%), there was significant 6-month improvement (85 ± 16% to 96 ± 6%, p < 0.01). 86% of respondents (69/80) expressed willingness to continue in a longer trial. The DeTAP study demonstrated rapid recruitment, high engagement, and physiologic reporting via the integration of digital technologies and dedicated study coordination. These findings may inform DCT designs for future cardiovascular trials.

COVID-19 is associated with higher risk of venous thrombosis, but not arterial thrombosis, compared with influenza: Insights from a large US cohort

Introduction

Infection with SARS-CoV-2 is typically compared with influenza to contextualize its health risks. SARS-CoV-2 has been linked with coagulation disturbances including arterial thrombosis, leading to considerable interest in antithrombotic therapy for Coronavirus Disease 2019 (COVID-19). However, the independent thromboembolic risk of SARS-CoV-2 infection compared with influenza remains incompletely understood. We evaluated the adjusted risks of thromboembolic events after a diagnosis of COVID-19 compared with influenza in a large retrospective cohort.

Methods

We used a US-based electronic health record (EHR) dataset linked with insurance claims to identify adults diagnosed with COVID-19 between April 1, 2020 and October 31, 2020. We identified influenza patients diagnosed between October 1, 2018 and April 31, 2019. Primary outcomes [venous composite of pulmonary embolism (PE) and acute deep vein thrombosis (DVT); arterial composite of ischemic stroke and myocardial infarction (MI)] and secondary outcomes were assessed 90 days post-diagnosis. Propensity scores (PS) were calculated using demographic, clinical, and medication variables. PS-adjusted hazard ratios (HRs) were calculated using Cox proportional hazards regression.

Results

There were 417,975 COVID-19 patients (median age 57y, 61% women), and 345,934 influenza patients (median age 47y, 66% women). Compared with influenza, patients with COVID-19 had higher venous thromboembolic risk (HR 1.53, 95% CI 1.38–1.70), but not arterial thromboembolic risk (HR 1.02, 95% CI 0.95–1.10). Secondary analyses demonstrated similar risk for ischemic stroke (HR 1.11, 95% CI 0.98–1.25) and MI (HR 0.93, 95% CI 0.85–1.03) and higher risk for DVT (HR 1.36, 95% CI 1.19–1.56) and PE (HR 1.82, 95% CI 1.57–2.10) in patients with COVID-19.

Conclusion

In a large retrospective US cohort, COVID-19 was independently associated with higher 90-day risk for venous thrombosis, but not arterial thrombosis, as compared with influenza. These findings may inform crucial knowledge gaps regarding the specific thromboembolic risks of COVID-19.

Application of the Quadruple Aim to evaluate the operational impact of a telemedicine program

Background

In response to the COVID-19 pandemic, telemedicine utilization has increased dramatically, yet most institutions lack a standardized approach to determine how much to invest in these programs.

Methods

We used the Quadruple Aim to evaluate the operational impact of CardioClick, a program replacing in-person follow-up visits with video visits in a preventive cardiology clinic. We examined data for 134 patients enrolled in CardioClick with 181 video follow-up visits and 276 patients enrolled in the clinic's traditional prevention program with 694 in-person follow-up visits.

Results

Patients in CardioClick and the cohort receiving in-person care were similar in terms of age (43 vs 45 years), gender balance (74% vs 79% male), and baseline clinical characteristics. Video follow-up visits were shorter than in-person visits in terms of clinician time (median 22 vs 30 min) and total clinic time (median 22 vs 68 min). Video visits were more likely to end on time than in-person visits (71 vs 11%, p < .001). Physicians more often completed video visit documentation on the day of the visit (56 vs 42%, p = .002).

Conclusions

Implementation of video follow-up visits in a preventive cardiology clinic was associated with operational improvements in the areas of efficiency, patient experience, and clinician experience. These benefits in three domains of the Quadruple Aim justify expanded use of telemedicine at our institution.

Implications

The Quadruple Aim provides a framework to evaluate telemedicine programs recently implemented in many health systems.

Level of evidence

Level III (retrospective comparative study).

COVID-19 is associated with higher risk of venous thrombosis, but not arterial thrombosis, compared with influenza: Insights from a large US cohort

Introduction

Infection with SARS-CoV-2 is typically compared with influenza to contextualize its health risks. SARS-CoV-2 has been linked with coagulation disturbances including arterial thrombosis, leading to considerable interest in antithrombotic therapy for Coronavirus Disease 2019 (COVID-19). However, the independent thromboembolic risk of SARS-CoV-2 infection compared with influenza remains incompletely understood. We evaluated the adjusted risks of thromboembolic events after a diagnosis of COVID-19 compared with influenza in a large retrospective cohort.

Methods

We used a US-based electronic health record (EHR) dataset linked with insurance claims to identify adults diagnosed with COVID-19 between April 1, 2020 and October 31, 2020. We identified influenza patients diagnosed between October 1, 2018 and April 31, 2019. Primary outcomes [venous composite of pulmonary embolism (PE) and acute deep vein thrombosis (DVT); arterial composite of ischemic stroke and myocardial infarction (MI)] and secondary outcomes were assessed 90 days post-diagnosis. Propensity scores (PS) were calculated using demographic, clinical, and medication variables. PS-adjusted hazard ratios (HRs) were calculated using Cox proportional hazards regression.

Results

There were 417,975 COVID-19 patients (median age 57y, 61% women), and 345,934 influenza patients (median age 47y, 66% women). Compared with influenza, patients with COVID-19 had higher venous thromboembolic risk (HR 1.53, 95% CI 1.38–1.70), but not arterial thromboembolic risk (HR 1.02, 95% CI 0.95–1.10). Secondary analyses demonstrated similar risk for ischemic stroke (HR 1.11, 95% CI 0.98–1.25) and MI (HR 0.93, 95% CI 0.85–1.03) and higher risk for DVT (HR 1.36, 95% CI 1.19–1.56) and PE (HR 1.82, 95% CI 1.57–2.10) in patients with COVID-19.

Conclusion

In a large retrospective US cohort, COVID-19 was independently associated with higher 90-day risk for venous thrombosis, but not arterial thrombosis, as compared with influenza. These findings may inform crucial knowledge gaps regarding the specific thromboembolic risks of COVID-19.

Validation of a pandemic-proof, decentralized cardiovascular trial: scalable design produces rapid recruitment, high engagement and protocol adherence in DeTAP (Decentralized Trial in Afib Patients)

Background

The COVID-19 pandemic has curtailed clinical trial activity significantly. Decentralized clinical trial (DCT) designs may lower cost, expand trial access, and reduce exposure risk for patients and staff. Whether such designs can be used for large, pivotal drug trials is not known.

Purpose

We performed a feasibility study to inform whether a large phase 3 Cardiovascular DCT can achieve high quality trial results and also withstand health crises such as the COVID-19 pandemic. The DeTAP (Decentralized Trial in Afib Patients) was a single-arm, observational study that integrated a suite of digital health technologies, including paired home sensor devices, into a 100% virtual trial experience for atrial fibrillation (AF) patients on anticoagulation.

Methods

We recruited 100 AF patients over age 55 on oral anticoagulation (OAC) by traditional methods or by social media ads placed California-wide. Subjects completed an online prescreening, uploaded their active OAC prescription, and completed an e-consent via SMS message link. Participants downloaded a customized study app to integrate surveys and data from study-supplied wireless blood pressure (BP) and 6 lead EKG sensors (Figure 1A). Participants completed pre- and post-study engagement surveys, weekly OAC adherence surveys, 4 study televisits, 4 ECG/BP readings, and 4 post-study surveys over a 6 month period. The primary endpoints were protocol engagement-based measurements that quantified percent completion of: 1) televisits 2) surveys, 3) ECG/BP readings requirements. Secondary endpoints were the % changes in: 1) OAC adherence (OACA), 2) nuisance bleeding (NB), 3) individual patient engagement surveys.

Results

100 participants were recruited in 26 days (traditional: 6 in 2 weeks; social media: 94 in 12 days) with a dramatic surge in enrollment driven by social media ads (Figure 1B, Table). A recruitment overflow occurred with &gt;200 eligible candidates on a waitlist. All key study completion metrics showed high compliance: televisit (91%); surveys (85%); ECG/BP completion (90%). Overall OACA was unchanged, but for subjects who reported low initial OACA, there was significant improvement at 6 months (85±16% to 98±6%; p=0.002). 47 participants (57%) reported NB, which did not correlate with OACA. Participant engagement measure scores (PAM-13) trended higher (baseline, 70%; 6 months, 74%, p=0.32). Lastly, study participants exhibited strong interest in participating in a larger experimental drug DCT study (90%) in the future.

Conclusion

The DeTAP study, conducted fully during the COVID-19 pandemic, demonstrates that a decentralized CV medical intervention trial is feasible and can achieve rapid recruitment, high study retention, physiologic and adverse event reporting, and high study engagement via the proper integration of digital technologies and a dedicated DCT study coordination effort. These findings could be informative for virtualizing large pivotal clinical trials at scale.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Bayer AG Figure 1. DeTAP Study Design and Recruitment TimelineTable 1. DeTAP Results

Initial Outcomes of CardioClick, a Telehealth Program for Preventive Cardiac Care: Observational Study

Background

Telehealth use has increased in specialty clinics, but there is limited evidence on the outcomes of telehealth in primary cardiovascular disease (CVD) prevention.

Objective

The objective of this study was to evaluate the initial outcomes of CardioClick, a telehealth primary CVD prevention program.

Methods

In 2017, the Stanford South Asian Translational Heart Initiative (a preventive cardiology clinic focused on high-risk South Asian patients) introduced CardioClick, which is a clinical pathway replacing in-person follow-up visits with video visits. We assessed patient engagement and changes in CVD risk factors in CardioClick patients and in a historical in-person cohort from the same clinic.

Results

In this study, 118 CardioClick patients and 441 patients who received in-person care were included. CardioClick patients were more likely to complete the clinic’s CVD prevention program (76/118, 64.4% vs 173/441, 39.2%, respectively; P<.001) and they did so in lesser time (mean, 250 days vs 307 days, respectively; P<.001) than the patients in the historical in-person cohort. Patients who completed the CardioClick program achieved reductions in CVD risk factors, including blood pressure, lipid concentrations, and BMI, which matched or exceeded those observed in the historical in-person cohort.

Conclusions

Telehealth can be used to deliver care effectively in a preventive cardiology clinic setting and may result in increased patient engagement. Further studies on telehealth outcomes are needed to determine the optimal role of virtual care models across diverse preventive medicine clinics.

Real-World Diagnosis and Treatment of Diabetic Kidney Disease

INTRODUCTION

People with type 2 diabetes mellitus (T2DM) and diabetic kidney disease (DKD) have increased morbidity and mortality risk. Angiotensin-converting enzyme inhibitors (ACEi) or angiotensin II receptor blockers (ARB) are recommended to slow kidney function decline in DKD. This representative, real-world data analysis of patients with T2DM was performed to detect onset of DKD and determine methods and timing of DKD diagnosis and time to initiation of ACEi/ARB therapy.

METHODS

Patients diagnosed with T2DM before January 1, 2016 who developed DKD between January 1, 2017 and June 30, 2019 were identified from a longitudinal ambulatory electronic health record (EHR) dataset (Veradigm Inc). Each record was analyzed using the CLinical INTelligence engine (CLINT™, HealthPals, Inc.) to identify delays and gaps in diagnosing DKD. DKD was diagnosed through two reduced estimated glomerular filtration rate (eGFR; < 60 mL/min/1.73 m²) measurements at least 90 days apart, a single elevated urine albumin-to-creatinine ratio (UACR; > 30 mg/g) measurement, or ICD-9/10 diagnosis codes for DKD and/or albuminuria. Time to diagnose (TTD), time to treat (TTT), and diagnosis to treatment time were assessed.

RESULTS

Of 6,499,409 patients with T2DM before January 2016, 245,978 developed DKD between January 1, 2017 and June 30, 2019. In this DKD cohort, ca. 50% were first identified through EHR diagnosis and ca. 50% by UACR or eGFR lab-based diagnosis. In patients who had UACR/eGFR assessed, more than 90% exhibited DKD-level results on the first diagnostic test. Average TTD after eGFR labs was 2 years; average TTT with ACEi/ARB was 6-9 months after DKD lab evidence. The majority of patients who developed DKD received ACEi/ARB therapy 6-7 months after diagnosis.

CONCLUSION

In a contemporary, large national cohort of patients with T2DM, progression to DKD was common but likely underrepresented. The low rate of DKD-screening labs, along with sizable delays in diagnosis of DKD and initiation of ACEi/ARB therapy, indicates that many patients who progress to DKD are not being properly treated.

Pleural effusions associated with squamous cell lung carcinoma have a low diagnostic yield and a poor prognosis

Background

Malignant pleural effusion (MPE) portends a poor prognosis in non-small cell lung cancer (NSCLC). However, the yield of pleural fluid cytology as well as survival of patients with MPE associated with squamous cell carcinoma versus adenocarcinoma is not well understood. We conducted this study to assess the diagnostic yield of pleural cytology and survival of patients with NSCLC related MPE.

Methods

We performed a single-center, retrospective analysis of patients with NSCLC related MPE between 2010 and 2017. Kaplan-Meier method was used to compare survival and Cox proportional hazards analysis to assess if squamous cell cytopathology was associated with mortality.

Results

We identified 277 patients, 29 with squamous cell and 248 with adenocarcinoma MPE. Pleural fluid cytology from initial thoracentesis was diagnostic in 13.8% (4/29) patients with squamous cell and 80.2% (199/248) with adenocarcinoma (P<0.001). Cytology from second thoracentesis was diagnostic in 13.3% (2/15) patients with squamous cell carcinoma, compared to 37.5% (12/32) with adenocarcinoma (P=0.17). There was no statistically significant difference in the pleural biopsy yield from medical pleuroscopy or video-assisted thoracoscopic surgery (VATS) in the two groups. The median survival of patients with squamous cell MPE was 112 [interquartile range (IQR): 44-220] days versus 194 (IQR: 54-523) days in adenocarcinoma (Log-rank test P=0.04). Multivariate Cox proportional hazards analysis showed that squamous cell cytopathology was independent predictor of mortality (hazard ratio for death of 1.73, 95% CI: 1.1-2.6; P=0.01).

Conclusions

Pleural fluid cytology has a low diagnostic yield in squamous cell carcinoma MPE, and these patients have a poor survival compared to lung adenocarcinoma.

Abstract 057: Beyond Convenience: Video Visits Can Increase The Efficiency Of Preventive Care Delivery

Introduction: In response to the COVID-19 pandemic, medical practices have expanded utilization of telehealth. Little is known about the operational impacts of transitioning from in-person to video visits in specialty clinics. In 2018, the Stanford South Asian Translational Heart Initiative (SSATHI), a preventive cardiology clinic focused on high-risk South Asian adults, introduced CardioClick, a program replacing in-person follow-up visits with video visits.

Hypothesis: We hypothesized that implementation of video visits increased the efficiency of clinic operations.

Methods: We extracted visit-level data from the EHR for 134 patients enrolled in CardioClick with video follow-up visits from June 14, 2018 to April 21, 2020 and a cohort of 276 patients enrolled in the in-person SSATHI prevention program with follow-up visits from September 11, 2014 to March 6, 2020.

Results: Patients in CardioClick and the in-person cohort were similar in terms of age (mean 45 years), gender balance (23 vs 21% female), and cardiometabolic risk profiles. There were 181 video and 637 in-person follow-up visits. Video visits were shorter than in-person visits, both in terms of total clinic time [median 22 min (IQR 16, 29) vs 67 min (48, 100)] and provider time required [median 22 min (IQR 16, 29) vs 30 min (12, 58)]. Video visits were more likely to end on time (71 vs 11%, p<0.001). The median video visit ended on time while the median in-person visit ended 32 min late (13, 70) (see Figure). Providers were also more likely to complete video visit documentation the same day (56 vs 42%, p=0.001).

Conclusions: In a preventive cardiology clinic, video follow-up visits required less clinic and provider time than in-person visits, were more likely to end on time, and were associated with increased same-day provider documentation completion. In conclusion, video visits offer benefits beyond their convenience and may increase the operational efficiency of specialty care practices focused on disease prevention, improving value in care delivery.

Ferumoxytol-enhanced cardiovascular magnetic resonance detection of early stage acute myocarditis

BACKGROUND

The diagnostic utility of cardiovascular magnetic resonance (CMR) is limited during the early stages of myocarditis. This study examined whether ferumoxytol-enhanced CMR (FE-CMR) could detect an earlier stage of acute myocarditis compared to gadolinium-enhanced CMR.

METHODS

Lewis rats were induced to develop autoimmune myocarditis. CMR (3 T, GE Signa) was performed at the early- (day 14, n = 7) and the peak-phase (day 21, n = 8) of myocardial inflammation. FE-CMR was evaluated as % myocardial dephasing signal loss on gradient echo images at 6 and 24 h (6 h- & 24 h-FE-CMR) following the administration of ferumoxytol (300μmolFe/kg). Pre- and post-contrast T2* mapping was also performed. Early (EGE) and late (LGE) gadolinium enhancement was obtained after the administration of gadolinium-DTPA (0.5 mmol/kg) on day 14 and 21. Healthy rats were used as control (n = 6).

RESULTS

Left ventricular ejection fraction (LVEF) was preserved at day 14 with inflammatory cells but no fibrosis seen on histology. EGE and LGE at day 14 both showed limited myocardial enhancement (EGE: 11.7 ± 15.5%; LGE: 8.7 ± 8.7%; both p = ns vs. controls). In contrast, 6 h-FE-CMR detected extensive myocardial signal loss (33.2 ± 15.0%, p = 0.02 vs. EGE and p < 0.01 vs. LGE). At day 21, LVEF became significantly decreased (47.4 ± 16.4% vs control: 66.2 ± 6.1%, p < 0.01) with now extensive myocardial involvement detected on EGE, LGE, and 6 h-FE-CMR (41.6 ± 18.2% of LV). T2* mapping also detected myocardial uptake of ferumoxytol both at day 14 (6 h R2* = 299 ± 112 s- 1vs control: 125 ± 26 s- 1, p < 0.01) and day 21 (564 ± 562 s- 1, p < 0.01 vs control). Notably, the myocardium at peak-phase myocarditis also showed significantly higher pre-contrast T2* (27 ± 5 ms vs control: 16 ± 1 ms, p < 0.001), and the extent of myocardial necrosis had a strong positive correlation with T2* (r = 0.86, p < 0.001).

CONCLUSIONS

FE-CMR acquired at 6 h enhance detection of early stages of myocarditis before development of necrosis or fibrosis, which could potentially enable appropriate therapeutic intervention.

Defining genotype-phenotype relationships in patients with hypertrophic cardiomyopathy using cardiovascular magnetic resonance imaging

PURPOSE

HCM is the most common inherited cardiomyopathy. Historically, there has been poor correlation between genotype and phenotype. However, CMR has the potential to more accurately assess disease phenotype. We characterized phenotype with CMR in a cohort of patients with confirmed HCM and high prevalence of genetic testing.

METHODS

Patients with a diagnosis of HCM, who had undergone contrast-enhanced CMR were identified. Left ventricular mass index (LVMI) and volumes were measured from steady-state free precession sequences. Late gadolinium enhancement (LGE) was quantified using the full width, half maximum method. All patients were prospectively followed for the development of septal reduction therapy, arrhythmia or death.

RESULTS

We included 273 patients, mean age 51.2 ± 15.5, 62.9% male. Of those patients 202 (74.0%) underwent genetic testing with 90 pathogenic, likely pathogenic, or rare variants and 13 variants of uncertain significance identified. Median follow-up was 1138 days. Mean LVMI was 82.7 ± 30.6 and 145 patients had late gadolinium enhancement (LGE). Patients with beta-myosin heavy chain (MYH7) mutations had higher LV ejection fraction (68.8 vs 59.1, p<0.001) than those with cardiac myosin binding protein C (MYBPC3) mutations. Patients with MYBPC3 mutations were more likely to have LVEF < 55% (29.7% vs 4.9%, p = 0.005) or receive a defibrillator than those with MYH7 mutations (54.1% vs 26.8%, p = 0.020).

CONCLUSIONS

We found that patients with MYBPC3 mutations were more likely to have impaired ventricular function and may be more prone to arrhythmic events. Larger studies using CMR phenotyping may be capable of identifying additional characteristics associated with less frequent genetic causes of HCM.

Myocardial viability of the peri-infarct region measured by T1 mapping post manganese-enhanced MRI correlates with LV dysfunction

BACKGROUND

Manganese-enhanced MRI (MEMRI) detects viable cardiomyocytes based on the intracellular manganese uptake via L-type calcium-channels. This study aimed to quantify myocardial viability based on manganese uptake by viable myocardium in the infarct core (IC), peri-infarct region (PIR) and remote myocardium (RM) using T1 mapping before and after MEMRI and assess their association with cardiac function and arrhythmogenesis.

METHODS

Fifteen female swine had a 60-minute balloon ischemia-reperfusion injury in the LAD. MRI (Signa 3T, GE Healthcare) and electrophysiological study (EPS) were performed 4 weeks later. MEMRI and delayed gadolinium-enhanced MRI (DEMRI) were acquired on LV short axis. The DEMRI positive total infarct area was subdivided into the regions of MEMRI-negative non-viable IC and MEMRI-positive viable PIR. T1 mapping was performed to evaluate native T1, post-MEMRI T1, and delta R1 (R1_post-R1_pre, where R1 equals 1/T1) of each territory. Their correlation with LV function and EPS data was assessed.

RESULTS

PIR was characterized by intermediate native T1 (1530.5 ± 75.2 ms) compared to IC (1634.7 ± 88.4 ms, p = 0.001) and RM (1406.4 ± 37.9 ms, p < 0.0001). Lower post-MEMRI T1 of PIR (1136.3 ± 99.6 ms) than IC (1262.6 ± 126.8 ms, p = 0.005) and higher delta R1 (0.23 ± 0.08 s^-1) of PIR than IC (0.18 ± 0.09 s^-1, p = 0.04) indicated higher myocardial manganese uptake of PIR compared to IC. Post-MEMRI T1 (r = -0.57, p = 0.02) and delta R1 (r = 0.51, p = 0.04) of PIR correlated significantly with LVEF.

CONCLUSIONS

PIR is characterized by higher manganese uptake compared to the infarct core. In the subacute phase post-IR, PIR viability measured by post-MEMRI T1 correlates with cardiac function.

An Alpha-1A Adrenergic Receptor Agonist Prevents Acute Doxorubicin Cardiomyopathy in Male Mice

Alpha-1 adrenergic receptors mediate adaptive effects in the heart and cardiac myocytes, and a myocyte survival pathway involving the alpha-1A receptor subtype and ERK activation exists in vitro. However, data in vivo are limited. Here we tested A61603 (N-[5-(4,5-dihydro-1H-imidazol-2-yl)-2-hydroxy-5,6,7,8-tetrahydronaphthalen-1-yl]methanesulfonamide), a selective imidazoline agonist for the alpha-1A. A61603 was the most potent alpha-1-agonist in activating ERK in neonatal rat ventricular myocytes. A61603 activated ERK in adult mouse ventricular myocytes and protected the cells from death caused by the anthracycline doxorubicin. A low dose of A61603 (10 ng/kg/d) activated ERK in the mouse heart in vivo, but did not change blood pressure. In male mice, concurrent subcutaneous A61603 infusion at 10 ng/kg/d for 7 days after a single intraperitoneal dose of doxorubicin (25 mg/kg) increased survival, improved cardiac function, heart rate, and cardiac output by echocardiography, and reduced cardiac cell necrosis and apoptosis and myocardial fibrosis. All protective effects were lost in alpha-1A-knockout mice. In female mice, doxorubicin at doses higher than in males (35-40 mg/kg) caused less cardiac toxicity than in males. We conclude that the alpha-1A-selective agonist A61603, via the alpha-1A adrenergic receptor, prevents doxorubicin cardiomyopathy in male mice, supporting the theory that alpha-1A adrenergic receptor agonists have potential as novel heart failure therapies.

Anticipatory Positive Urine Tests for Bladder Cancer

PURPOSE

The aim of this study was to establish the criteria defining an anticipatory positive test for bladder cancer.

METHODS

We reviewed all patients at our institution who underwent urine cytology or UroVysion fluorescence in situ hybridization (FISH) and cystoscopy from 2003 to 2012. Test performance and cancer anticipation was assessed using generalized linear mixed models, mixed-effects proportional hazards models, and cumulative incidence curves using tests performed within 30 days of each other as well as within a lag time of 1 year.

RESULTS

Overall, 6729 urine tests (4729 cytology and 2040 UroVysion FISH) were paired with gold-standard cystoscopies. Sensitivity and specificity were 63 and 41% for cytology, and 37 and 84% for UroVysion FISH, respectively. A 1-year lag time allowed for cancer anticipation and neither test improved. Among patients with positive cytology and initially negative cystoscopy, the hazard ratio of developing a bladder tumor at 1 year was 1.83; 76% of these patients developed a tumor within 1 year. Similarly, among patients with a positive FISH and initially negative cystoscopy, the hazard ratio of developing a bladder tumor at 1 year was 1.56; 40% of these patients developed a tumor within 1 year.

CONCLUSIONS

Urine-based tests for bladder cancer are frequently falsely positive. With further follow-up time, some of these false positive tests are vindicated as true (anticipatory) positive tests, although many will remain false positives. We developed statistical criteria to determine if a test anticipates future cancers or not.

Apelin-13 infusion salvages the peri-infarct region to preserve cardiac function after severe myocardial injury

BACKGROUND

Apelin-13 (A13) regulates cardiac homeostasis. However, the effects and mechanism of A13 infusion after an acute myocardial injury (AMI) have not been elucidated. This study assesses the restorative effects and mechanism of A13 on the peri-infarct region in murine AMI model.

METHODS

51 FVB/N mice (12weeks, 30g) underwent AMI. A week following injury, continuous micro-pump infusion of A13 (0.5μg/g/day) and saline was initiated for 4-week duration. Dual contrast MRI was conducted on weeks 1, 2, 3, and 5, consisting of delayed-enhanced and manganese-enhanced MRI. Four mice in each group were followed for an extended period of 4weeks without further infusion and underwent MRI scans on weeks 7 and 9.

RESULTS

A13 infusion demonstrated preserved LVEF compared to saline from weeks 1 to 4 (21.9±3.2% to 23.1±1.7%* vs. 23.5±1.7% to 16.9±2.8%, *p=0.02), which persisted up to 9weeks post-MI (+1.4%* vs. -9.4%, *p=0.03). Mechanistically, dual contrast MRI demonstrated significant decrease in the peri-infarct and scar % volume in A13 group from weeks 1 to 4 (15.1 to 7.4% and 34.3 to 25.1%, p=0.02, respectively). This was corroborated by significant increase in 5-ethynyl-2'-deoxyuridine (EdU(+)) cells by A13 vs. saline groups in the peri-infarct region (16.5±3.1% vs. 8.1±1.6%; p=0.04), suggesting active cell mitosis. Finally, significantly enhanced mobilization of CD34(+) cells in the peripheral blood and up-regulation of APJ, fibrotic, and apoptotic genes in the peri-infarct region were found.

CONCLUSIONS

A13 preserves cardiac performance by salvaging the peri-infarct region and may contribute to permanent restoration of the severely injured myocardium.

Multimodality Molecular Imaging of Cardiac Cell Transplantation: Part II. In Vivo Imaging of Bone Marrow Stromal Cells in Swine with PET/CT and MR Imaging

Purpose To quantitatively determine the limit of detection of marrow stromal cells (MSC) after cardiac cell therapy (CCT) in swine by using clinical positron emission tomography (PET) reporter gene imaging and magnetic resonance (MR) imaging with cell prelabeling. Materials and Methods Animal studies were approved by the institutional administrative panel on laboratory animal care. Seven swine received 23 intracardiac cell injections that contained control MSC and cell mixtures of MSC expressing a multimodality triple fusion (TF) reporter gene (MSC-TF) and bearing superparamagnetic iron oxide nanoparticles (NP) (MSC-TF-NP) or NP alone. Clinical MR imaging and PET reporter gene molecular imaging were performed after intravenous injection of the radiotracer fluorine 18-radiolabeled 9-[4-fluoro-3-(hydroxyl methyl) butyl] guanine ((18)F-FHBG). Linear regression analysis of both MR imaging and PET data and nonlinear regression analysis of PET data were performed, accounting for multiple injections per animal. Results MR imaging showed a positive correlation between MSC-TF-NP cell number and dephasing (dark) signal (R(2) = 0.72, P = .0001) and a lower detection limit of at least approximately 1.5 × 10(7) cells. PET reporter gene imaging demonstrated a significant positive correlation between MSC-TF and target-to-background ratio with the linear model (R(2) = 0.88, P = .0001, root mean square error = 0.523) and the nonlinear model (R(2) = 0.99, P = .0001, root mean square error = 0.273) and a lower detection limit of 2.5 × 10(8) cells. Conclusion The authors quantitatively determined the limit of detection of MSC after CCT in swine by using clinical PET reporter gene imaging and clinical MR imaging with cell prelabeling. (©) RSNA, 2016 Online supplemental material is available for this article.

Multimodality Molecular Imaging of Cardiac Cell Transplantation: Part I. Reporter Gene Design, Characterization, and Optical in Vivo Imaging of Bone Marrow Stromal Cells after Myocardial Infarction

Purpose To use multimodality reporter-gene imaging to assess the serial survival of marrow stromal cells (MSC) after therapy for myocardial infarction (MI) and to determine if the requisite preclinical imaging end point was met prior to a follow-up large-animal MSC imaging study. Materials and Methods Animal studies were approved by the Institutional Administrative Panel on Laboratory Animal Care. Mice (n = 19) that had experienced MI were injected with bone marrow-derived MSC that expressed a multimodality triple fusion (TF) reporter gene. The TF reporter gene (fluc2-egfp-sr39ttk) consisted of a human promoter, ubiquitin, driving firefly luciferase 2 (fluc2), enhanced green fluorescent protein (egfp), and the sr39tk positron emission tomography reporter gene. Serial bioluminescence imaging of MSC-TF and ex vivo luciferase assays were performed. Correlations were analyzed with the Pearson product-moment correlation, and serial imaging results were analyzed with a mixed-effects regression model. Results Analysis of the MSC-TF after cardiac cell therapy showed significantly lower signal on days 8 and 14 than on day 2 (P = .011 and P = .001, respectively). MSC-TF with MI demonstrated significantly higher signal than MSC-TF without MI at days 4, 8, and 14 (P = .016). Ex vivo luciferase activity assay confirmed the presence of MSC-TF on days 8 and 14 after MI. Conclusion Multimodality reporter-gene imaging was successfully used to assess serial MSC survival after therapy for MI, and it was determined that the requisite preclinical imaging end point, 14 days of MSC survival, was met prior to a follow-up large-animal MSC study. (©) RSNA, 2016 Online supplemental material is available for this article.

The diagnostic accuracy of urine-based tests for bladder cancer varies greatly by patient

Background

Spectrum effects refer to the phenomenon that test performance varies across subgroups of a population. When spectrum effects occur during diagnostic testing for cancer, difficult patient misdiagnoses can occur. Our objective was to evaluate the effect of test indication, age, gender, race, and smoking status on the performance characteristics of two commonly used diagnostic tests for bladder cancer, urine cytology and fluorescence in situ hybridization (FISH).

Methods

We assessed all subjects who underwent cystoscopy, cytology, and FISH at our institution from 2003 to 2012. The standard diagnostic test performance metrics were calculated using marginal models to account for clustered/repeated measures within subjects. We calculated test performance for the overall cohort by test indication as well as by key patient variables: age, gender, race, and smoking status.

Results

A total of 4023 cystoscopy-cytology pairs and 1696 FISH-cystoscopy pairs were included in the analysis. In both FISH and cytology, increasing age, male gender, and history of smoking were associated with increased sensitivity and decreased specificity. FISH performance was most impacted by age, with an increase in sensitivity from 17 % at age 40 to 49 % at age 80. The same was true of cytology, with an increase in sensitivity from 50 % at age 40 to 67 % at age 80. Sensitivity of FISH was higher for a previous diagnosis of bladder cancer (46 %) than for hematuria (26 %). Test indication had no impact on the performance of cytology and race had no significant impact on the performance of either test.

Conclusions

The diagnostic performance of urine cytology and FISH vary significantly according to the patient demographic in which they were tested. Hence, the reporting of spectrum effects in diagnostic tests should become part of standard practice. Patient-related factors must contextualize the clinicians’ interpretation of test results and their decision-making.

Aligned nanofibrillar collagen scaffolds - Guiding lymphangiogenesis for treatment of acquired lymphedema

Secondary lymphedema is a common disorder associated with acquired functional impairment of the lymphatic system. The goal of this study was to evaluate the therapeutic efficacy of aligned nanofibrillar collagen scaffolds (BioBridge) positioned across the area of lymphatic obstruction in guiding lymphatic regeneration. In a porcine model of acquired lymphedema, animals were treated with BioBridge scaffolds, alone or in conjunction with autologous lymph node transfer as a source of endogenous lymphatic growth factor. They were compared with a surgical control group and a second control group in which the implanted BioBridge was supplemented with exogenous vascular endothelial growth factor-C (VEGF-C). Three months after implantation, immunofluorescence staining of lymphatic vessels demonstrated a significant increase in lymphatic collectors within close proximity to the scaffolds. To quantify the functional impact of scaffold implantation, bioimpedance was used as an early indicator of extracellular fluid accumulation. In comparison to the levels prior to implantation, the bioimpedance ratio was significantly improved only in the experimental BioBridge recipients with or without lymph node transfer, suggesting restoration of functional lymphatic drainage. These results further correlated with quantifiable lymphatic collectors, as visualized by contrast-enhanced computed tomography. They demonstrate the therapeutic potential of BioBridge scaffolds in secondary lymphedema.

Manganese-Enhanced Magnetic Resonance Imaging Enables In Vivo Confirmation of Peri-Infarct Restoration Following Stem Cell Therapy in a Porcine Ischemia-Reperfusion Model

Background

The exact mechanism of stem cell therapy in augmenting the function of ischemic cardiomyopathy is unclear. In this study, we hypothesized that increased viability of the peri-infarct region (PIR) produces restorative benefits after stem cell engraftment. A novel multimodality imaging approach simultaneously assessed myocardial viability (manganese-enhanced magnetic resonance imaging [MEMRI]), myocardial scar (delayed gadolinium enhancement MRI), and transplanted stem cell engraftment (positron emission tomography reporter gene) in the injured porcine hearts.

Methods and Results

Twelve adult swine underwent ischemia–reperfusion injury. Digital subtraction of MEMRI-negative myocardium (intrainfarct region) from delayed gadolinium enhancement MRI–positive myocardium (PIR and intrainfarct region) clearly delineated the PIR in which the MEMRI-positive signal reflected PIR viability. Human amniotic mesenchymal stem cells (hAMSCs) represent a unique population of immunomodulatory mesodermal stem cells that restored the murine PIR. Immediately following hAMSC delivery, MEMRI demonstrated an increased PIR viability signal compared with control. Direct PIR viability remained higher in hAMSC-treated hearts for >6 weeks. Increased PIR viability correlated with improved regional contractility, left ventricular ejection fraction, infarct size, and hAMSC engraftment, as confirmed by immunocytochemistry. Increased MEMRI and positron emission tomography reporter gene signal in the intrainfarct region and the PIR correlated with sustained functional augmentation (global and regional) within the hAMSC group (mean change, left ventricular ejection fraction: hAMSC 85±60%, control 8±10%; P<0.05) and reduced chamber dilatation (left ventricular end-diastole volume increase: hAMSC 24±8%, control 110±30%; P<0.05).

Conclusions

The positron emission tomography reporter gene signal of hAMSC engraftment correlates with the improved MEMRI signal in the PIR. The increased MEMRI signal represents PIR viability and the restorative potential of the injured heart. This in vivo multimodality imaging platform represents a novel, real-time method of tracking PIR viability and stem cell engraftment while providing a mechanistic explanation of the therapeutic efficacy of cardiovascular stem cells.

Relationship between echocardiographic and magnetic resonance derived measures of right ventricular size and function in patients with pulmonary hypertension

BACKGROUND

Transthoracic echocardiographic (TTE) imaging is the mainstay of clinical practice for evaluating right ventricular (RV) size and function, but its accuracy in patients with pulmonary hypertension has not been well validated.

METHODS

Magnetic resonance imaging (MRI) and TTE images were retrospectively reviewed in 40 consecutive patients with pulmonary hypertension. RV and left ventricular volumes and ejection fractions were calculated using MRI. TTE areas and indices of RV ejection fraction (RVEF) were compared.

RESULTS

The average age was 42 ± 12 years, with a majority of women (85%). There was a wide range of mean pulmonary arterial pressures (27-81 mm Hg) and RV end-diastolic volumes (111-576 mL), RVEFs (8%-67 %), and left ventricular ejection fractions (26%-72%) by MRI. There was a strong association between TTE and MRI-derived parameters: RV end-diastolic area (by TTE imaging) and RV end-diastolic volume (by MRI), R(2) = 0.78 (P < .001); RV fractional area change by TTE imaging and RVEF by MRI, R(2) = 0.76 (P < .001); and tricuspid annular plane systolic excursion by TTE imaging and RVEF by MRI, R(2) = 0.64 (P < .001). By receiver operating characteristic curve analysis, an RV fractional area change < 25% provided excellent discrimination of moderate systolic dysfunction (RVEF < 35%), with an area under the curve of 0.97 (P < .001). An RV end-diastolic area index of 18 cm(2)/m(2) provided excellent discrimination for moderate RV enlargement (area under the curve, 0.89; P < .001).

CONCLUSIONS

Echocardiographic estimates of RV volume (by RV end-diastolic area) and function (by RV fractional area change and tricuspid annular plane systolic excursion) offer good approximations of RV size and function in patients with pulmonary hypertension and allow the accurate discrimination of normal from abnormal.

Chemoprevention gene therapy (CGT): novel combinatorial approach for preventing and treating pancreatic cancer

Pancreatic cancer remains one of the deadliest of all cancers despite aggressive surgical treatment combined with adjuvant radiotherapy and chemotherapy. Chemoresistance and radioresistance are the principal causes of failure of pancreatic cancer patients to respond to therapy. Conditionally replication competent adenovirus (CRCA)-based cancer gene therapy is an innovative strategy for treating cancers displaying inherent resistance to treatment. Limitations of current adenovirus (Ad)-based gene therapies for malignant tumors include lack of cancer-specificity, and effective and targeted delivery. To remedy this situation, CRCAs have been designed that express E1A, necessary for Ad replication, under the control of a cancer-specific progression elevated gene-3 promoter (PEG-Prom) with concomitant expression of an immunomodulatory cytokine, such as mda-7/IL-24 or interferon-γ (IFN-γ), under the control of a ubiquitous and strong cytomegalovirus promoter (CMV-Prom) from the E3 region. These bipartite CRCAs, when armed with a transgene, are called cancer terminator viruses (CTVs), i.e., Ad.PEG-E1A-CMV-mda-7 (CTV-M7) and Ad.PEG-E1A-CMV-IFN-γ (CTV-γ), because of their universal effectiveness in cancer treatment irrespective of p53/pRb/p16 or other genetic alterations in tumor cells. In addition to their selective oncolytic effects in tumor cells, the potent 'bystander antitumor' properties of MDA-7/IL-24 and IFN-γ embody the CTVs with expanded treatment properties for both primary and distant cancers. Pancreatic cancer cells display a "translational block" of mda-7/IL-24 mRNA, limiting production of MDA-7/IL-24 protein and cancer-specific apoptosis. Specific chemopreventive agents abrogate this "translational block" resulting in pancreatic cancer-specific killing. This novel chemoprevention gene therapy (CGT) strategy holds promise for both prevention and treatment of pancreatic cancers where all other strategies have proven ineffective.

A novel stress echocardiography pattern for myocardial bridge with invasive structural and hemodynamic correlation

Background

Patients with a myocardial bridge (MB) and no significant obstructive coronary artery disease (CAD) may experience angina presumably from ischemia, but noninvasive assessment has been limited and the underlying mechanism poorly understood. This study seeks to correlate a novel exercise echocardiography (EE) finding for MBs with invasive structural and hemodynamic measurements.

Methods and Results

Eighteen patients with angina and an EE pattern of focal end‐systolic to early‐diastolic buckling in the septum with apical sparing were prospectively enrolled for invasive assessment. This included coronary angiography, left anterior descending artery (LAD) intravascular ultrasound (IVUS), and intracoronary pressure and Doppler measurements at rest and during dobutamine stress. All patients were found to have an LAD MB on IVUS. The ratios of diastolic intracoronary pressure divided by aortic pressure at rest (Pd/Pa) and during dobutamine stress (diastolic fractional flow reserve [dFFR]) and peak Doppler flow velocity recordings at rest and with stress were successfully performed in 14 patients. All had abnormal dFFR (≤0.75) at stress within the bridge, distally or in both positions, and on average showed a more than doubling in peak Doppler flow velocity inside the MB at stress. Seventy‐five percent of patients had normalization of dFFR distal to the MB, with partial pressure recovery and a decrease in peak Doppler flow velocity.

Conclusions

A distinctive septal wall motion abnormality with apical sparing on EE is associated with a documented MB by IVUS and a decreased dFFR. We posit that the septal wall motion abnormality on EE is due to dynamic ischemia local to the compressed segment of the LAD from the increase in velocity and decrease in perfusion pressure, consistent with the Venturi effect.