Predicting in-hospital mortality among patients admitted with a diagnosis of heart failure: a machine learning approach

Existing risk prediction models for hospitalized heart failure patients are limited. We identified patients hospitalized with a diagnosis of heart failure between 7 May 2013 and 26 April 2022 from a large academic, quaternary care medical centre (training cohort). Demographics, medical comorbidities, vitals, and labs were collected and were used to construct random forest machine learning models to predict in-hospital mortality. Models were compared with logistic regression, and to commonly used heart failure risk scores. The models were subsequently validated in patients hospitalized with a diagnosis of heart failure from a second academic, community medical centre (validation cohort). The entire cohort comprised 21 802 patients, of which 14 539 were in the training cohort and 7263 were in the validation cohort. The median age (25th-75th percentile) was 70 (58-82) for the entire cohort, 43.2% were female, and 6.7% experienced inpatient mortality. In the overall cohort, 7621 (35.0%) patients had heart failure with reduced ejection fraction (EF ≤ 40%), 1271 (5.8%) had heart failure with mildly reduced EF (EF 41-49%), and 12 910 (59.2%) had heart failure with preserved EF (EF ≥ 50%). Random forest models in the validation cohort demonstrated a c-statistic (95% confidence interval) of 0.96 (0.95-0.97), sensitivity (SN) of 87.3%, and specificity (SP) of 90.6% for the prediction of in-hospital mortality. Models for those with HFrEF demonstrated a c-statistic of 0.96 (0.94-0.98), SN 88.2%, and SP 91.0%, and those for patients with HFpEF showed a c-statistic of 0.95 (0.93-0.97), SN 87.4%, and SP 89.5% for predicting in-hospital mortality. The random forest model significantly outperformed logistic regression (c-statistic 0.87, SN 75.9%, and SP 86.9%), and current existing risk scores including the Acute Decompensated Heart Failure National Registry risk score (c-statistic of 0.70, SN 69%, and SP 62%), and the Get With the Guidelines-Heart Failure risk score (c-statistic 0.69, SN 67%, and SP 63%); P < 0.001 for comparison. Machine learning models built from commonly recorded patient information can accurately predict in-hospital mortality among patients hospitalized with a diagnosis of heart failure.

Early Utilization of Mechanical Circulatory Support in Acute Myocardial Infarction Complicated by Cardiogenic Shock: The National Cardiogenic Shock Initiative

BACKGROUND

Acute myocardial infarction complicated by cardiogenic shock (AMI-CS) is associated with significant morbidity and mortality. Mechanical circulatory support (MCS) devices increase systemic blood pressure and end organ perfusion while reducing cardiac filling pressures.

METHODS AND RESULTS

The National Cardiogenic Shock Initiative (NCT03677180) is a single-arm, multicenter study. The purpose of this study was to assess the feasibility and effectiveness of utilizing early MCS with Impella in patients presenting with AMI-CS. The primary end point was in-hospital mortality. A total of 406 patients were enrolled at 80 sites between 2016 and 2020. Average age was 64±12 years, 24% were female, 17% had a witnessed out-of-hospital cardiac arrest, 27% had in-hospital cardiac arrest, and 9% were under active cardiopulmonary resuscitation during MCS implantation. Patients presented with a mean systolic blood pressure of 77.2±19.2 mm Hg, 85% of patients were on vasopressors or inotropes, mean lactate was 4.8±3.9 mmol/L and cardiac power output was 0.67±0.29 watts. At 24 hours, mean systolic blood pressure improved to 103.9±17.8 mm Hg, lactate to 2.7±2.8 mmol/L, and cardiac power output to 1.0±1.3 watts. Procedural survival, survival to discharge, survival to 30 days, and survival to 1 year were 99%, 71%, 68%, and 53%, respectively.

CONCLUSIONS

Early use of MCS in AMI-CS is feasible across varying health care settings and resulted in improvements to early hemodynamics and perfusion. Survival rates to hospital discharge were high. Given the encouraging results from our analysis, randomized clinical trials are warranted to assess the role of utilizing early MCS, using a standardized, multidisciplinary approach.

Outcomes in orthotopic heart transplantation following pacemaker implantation

BACKGROUND

Bradyarrhythmias including sinus node dysfunction (SND) and atrioventricular block (AVB) can necessitate pacemaker (PPM) implantation in orthotopic heart transplant (OHT) recipients. Prior studies have shown conflicting findings regarding the effect of PPM implantation on survival. We evaluated the effect of PPM indication on long-term re-transplant-free survival in OHT patients.

METHODS

We conducted a retrospective cohort study of OHT patients at UCLA Medical Center from 1985 to 2018. Indication for PPM (SND, AVB) was identified. Cox proportional hazards model with pacemaker implantation as a time-varying covariate was used to evaluate its effect on the primary endpoint of retransplant or death. We included 1609 OHTs in 1511 adult patients with median follow-up of 12 years.

RESULTS

At transplant, patients were aged 53 ± 13 years and 1125 (74.5%) were male. Pacemakers were implanted in 109 (7.2%) patients; 65 for SND (4.3%) and 43 for AVB (2.8%). Repeat OHT was performed in 103 (6.4%) cases and 798 (52.8%) patients died during the follow-up period. The risk of the primary endpoint was significantly higher in patients requiring PPM for AVB (HR 3.0, 95% CI 2.1-4.2, p < .01) after controlling for age at OHT, gender, hypertension, diabetes, renal disease, history of repeat OHT, acute rejection, transplant coronary vasculopathy, and atrial fibrillation, but not PPM for SND (HR 1.0, 95% CI 0.70-1.4, p = 1.0).

CONCLUSIONS

Patients who required PPM for AVB, but not SND, were at significantly higher risk of death or retransplant compared to patients who did not require PPM.

Exploring the Relationship between Epigenetic DNA Methylation and Cardiac Fibrosis through Raman Microspectroscopy

Cardiomyopathies are associated with fibrotic remodeling of the heart, which is characterized by the excessive accumulation of collagen type I (COL I) due to chronic inflammation and suspected epigenetic influences. Despite the severity and high mortality rate of cardiac fibrosis, current treatment options are often inadequate, underscoring the importance of gaining a deeper understanding of the disease's underlying molecular and cellular mechanisms. In this study, the extracellular matrix (ECM) and nuclei in fibrotic areas of different cardiomyopathies were molecularly characterized by Raman microspectroscopy and imaging and compared to the control myocardium. Patient samples were obtained from heart tissue affected by ischemia, hypertrophy, and dilated cardiomyopathy and analyzed for fibrosis through conventional histology and marker-independent Raman microspectroscopy (RMS). Prominent differences between control myocardium and cardiomyopathies were revealed by spectral deconvolution of COL I Raman spectra. Statistically significant differences were identified in the amide I region of spectral subpeak at 1608 cm^-1, which is a representative endogenous marker for alterations in the structural conformation of COL I fibers. Moreover, epigenetic 5mC DNA modification was identified within cell nuclei by multivariate analysis. A statistically significant increase in signal intensities of spectral features indicative of DNA methylation was detected in cardiomyopathies in accordance with immunofluorescence 5mC staining. Overall, RMS is a versatile technology in the discrimination of cardiomyopathies based on molecular evaluation of COL I and nuclei, while providing insights into the pathogenesis of the diseases.

Raman microspectroscopy identifies fibrotic tissues in collagen-related disorders via deconvoluted collagen type I spectra

Fibrosis is a consequence of the pathological remodeling of extracellular matrix (ECM) structures in the connective tissue of an organ. It is often caused by chronic inflammation, which over time, progressively leads to an excess deposition of collagen type I (COL I) that replaces healthy tissue structures, in many cases leaving a stiff scar. Increasing fibrosis can lead to organ failure and death; therefore, developing methods that potentially allow real-time monitoring of early onset or progression of fibrosis are highly valuable. In this study, the ECM structures of diseased and healthy human tissue from multiple organs were investigated for the presence of fibrosis using routine histology and marker-independent Raman microspectroscopy and Raman imaging. Spectral deconvolution of COL I Raman spectra allowed the discrimination of fibrotic and non-fibrotic COL I fibers. Statistically significant differences were identified in the amide I region of the spectral subpeak at 1608 cm^-1, which was deemed to be representative for structural changes in COL I fibers in all examined fibrotic tissues. Raman spectroscopy-based methods in combination with this newly discovered spectroscopic biomarker potentially offer a diagnostic approach to non-invasively track and monitor the progression of fibrosis. STATEMENT OF SIGNIFICANCE: Current diagnosis of fibrosis still relies on histopathological examination with invasive biopsy procedures. Although, several non-invasive imaging techniques such as positron emission tomography, single-photon emission computed tomography and second harmonic generation are gradually employed in preclinical or clinical studies, these techniques are limited in spatial resolution and the morphological interpretation highly relies on individual experience and knowledge. In this study, we propose a non-destructive technique, Raman microspectroscopy, to discriminate fibrotic changes of collagen type I based on a molecular biomarker. The changes of the secondary structure of collagen type I can be identified by spectral deconvolution, which potentially can provide an automatic diagnosis for fibrotic tissues in the clinical applicaion.

Outcomes of heart transplant recipients bridged with percutaneous versus durable left ventricular assist devices

BACKGROUND

The new United Network for Organ Sharing (UNOS) heart allocation policy prioritizes temporary percutaneous over durable left ventricular assist devices (LVAD) as bridge to transplant. We sought to examine 1-year outcomes of heart transplant recipients bridged with Impella versus durable LVADs.

METHODS

All primary adult orthotopic heart transplant recipients registered in UNOS between January 2016 and June 2021 were analyzed. Recipients were identified as being bridged with isolated durable or percutaneous LVAD at the time of transplant. Baseline characteristics were compared and 1-year survival was examined using the Kaplan Meier method and multivariable Cox proportional hazards regression.

RESULTS

During our study period, heart transplant recipients bridged with LVADs were divided between 5422(94%) durable and 324(6%) percutaneous options. Impella-bridged recipients were more likely to be status 1A under the old allocation system (98% vs. 70%, p < .01) and status 2 or higher under the new allocation system (99% vs. 24%, p < .01). Impella-bridged recipients were less likely to be obese (27% vs. 42%, p < .01), have ischemic cardiomyopathy (27% vs. 34%, p < .01), and were more likely to be on inotropic agents at the time of transplant (68% vs. 6%, p < .01). One-year post-transplant survival was not significantly different between the two groups on univariable (HR .87, 95% CI .56-1.37) or multivariable analysis (aHR .63, 95% CI .37-1.07).

CONCLUSIONS

Following the UNOS allocation policy change, Impella utilization has increased with no significant difference in 1-year survival compared to bridge with durable LVADs. Impella may be a reasonable alternative to durable LVADs in select patients.

Early trends in cardiac allograft vasculopathy after implementation of the 2018 donor heart allocation policy in the United States

STUDY OBJECTIVE

To evaluate the impact of the new donor heart allocation system implemented in the United States in October 2018 on development of early cardiac allograft vasculopathy (CAV).

DESIGN

Retrospective cohort study.

PARTICIPANTS

Adult (≥ 18 years) heart transplant recipients registered in the United Network for Organ Sharing database between October 18, 2015 and October 17, 2018 (old system) and October 18, 2018 and May 31, 2020 (new system).

MAIN OUTCOME MEASURE

Incidence of angiographic CAV at 1 year (accelerated CAV) in the overall transplant population and among the highest acuity subgroup-Status 1A (old) and Status 1 or 2 (new). We included recipient and donor demographic, cardiovascular, and transplant factors in multivariable logistic regression models to identify predictors of accelerated CAV.

RESULTS

Of 10,375 transplant recipients, 6,660 (64%) and 3,715 (36%) were listed in the old and new allocation cohorts, respectively. The incidence of accelerated CAV was 521 (8%) in the old period compared with 272 (7%) in the new period (P = .36). Similar incidence rates were observed in the highest acuity subgroup-363 (8%) compared with 143 (7%), respectively (P = .13). In adjusted analyses of the high-acuity cohort, the new allocation system was not associated with a higher likelihood of accelerated CAV (odds ratio = 0.87, 95% confidence interval: 0.70-1.08, P = .20).

CONCLUSIONS

The new donor heart allocation system is not associated with development of accelerated angiographic CAV at 1 year, including among recipients requiring the most urgent transplants.

Characteristics and outcomes of patients presenting with acute myocardial infarction and cardiogenic shock during COVID-19

Objectives

To evaluate characteristics and outcomes of patients presenting with acute myocardial infarction and cardiogenic shock (AMICS) during the coronavirus disease 2019 (COVID‐19) pandemic.

Background

The COVID‐19 pandemic has created challenges in delivering acute cardiovascular care. Quality measures and outcomes of patients presenting with AMICS during COVID‐19 in the United States have not been well described.

Methods

We identified 406 patients from the National Cardiogenic Shock Initiative (NCSI) with AMICS and divided them into those presenting before (N = 346, 5/9/2016−2/29/2020) and those presenting during the COVID‐19 pandemic (N = 60, 3/1/2020−11/10/2020). We compared baseline clinical data, admission characteristics, and outcomes.

Results

The median age of the cohort was 64 years, and 23.7% of the group was female. There were no significant differences in age, sex, and medical comorbidities between the two groups. Patients presenting during the pandemic were less likely to be Black compared to those presenting prior. Median door to balloon (90 vs. 88 min, p = 0.38), door to support (88 vs. 78 min, p = 0.13), and the onset of shock to support (74 vs. 62 min, p = 0.15) times were not significantly different between the two groups. Patients presented with ST‐elevation myocardial infarction more often during the COVID‐19 period (95.0% vs. 80.0%, p = 0.005). In adjusted logistic regression models, COVID‐19 period did not significantly associate with survival to discharge (odds ratio [OR] 1.09, 95% confidence interval [CI] 0.54−2.19, p = 0.81) or with 1‐month survival (OR 0.82, 95% CI 0.42−1.61, p = 0.56).

Conclusions

Care of patients presenting with AMICS has remained robust among hospitals participating in the NCSI during the COVID‐19 pandemic.

Hemodynamic effects of COVID-19 vaccination in hospitalized patients awaiting heart transplantation

Background

The hemodynamic effects of pre-transplant vaccination against COVID-19 among heart transplant candidates hospitalized for advanced heart failure remains unknown.

Methods

A retrospective chart review was conducted at a high-volume transplant center from January through December 2021. 22 COVID-19 vaccination events occurred among patients hospitalized for decompensated heart failure while awaiting transplantation. Primary outcomes included inotrope and vasopressor dosages. Secondary outcomes included vital signs, pulmonary artery catheter measurements, diuretic dosages, and renal function. Data were extracted 24 h before through 72 h after vaccination.

Results

One of 22 vaccination events was associated with hemodynamic changes requiring increased inotropic and vasopressor support post-vaccination. In all other cases, transient hemodynamic changes occurred without need for escalated therapy.

Conclusions

COVID-19 vaccination can be administered safely to most critically ill patients with advanced heart failure including those awaiting transplantation. All patients should be monitored closely as some may be susceptible to significant hemodynamic changes.

Fractional Flow Reserve in End-Stage Liver Disease

Fractional flow reserve (FFR) determines the functional significance of epicardial stenoses assuming negligible venous pressure (P_v) and microvascular resistance. However, these assumptions may be invalid in end-stage liver disease (ESLD) because of fluctuating P_v and vasodilation. Accordingly, all patients with ESLD who underwent right-sided cardiac catheterization and coronary angiography with FFR as part of their orthotopic liver transplantation evaluation between 2013 and 2018 were included in the present study. Resting mean distal coronary pressure (P_d)/mean aortic pressure (P_a), FFR, and P_v were measured. FFR accounting for P_v (FFR - P_v) was defined as (P_d - P_v)/(P_a - P_v). The hyperemic effect of adenosine was defined as resting P_d/P_a - FFR. The primary outcome was all-cause mortality at 1 year. In 42 patients with ESLD, 49 stenoses were interrogated by FFR (90% were <70% diameter stenosis). Overall, the median model for ESLD score was 16.5 (10.8 to 25.5), FFR was 0.87 (0.81 to 0.94), P_v was 8 mm Hg (4 to 14), FFR-P_v was 0.86 (0.80 to 0.94), and hyperemic effect of adenosine was 0.06 (0.02 to 0.08). FFR-P_v led to the reclassification of 1 stenosis as functionally significant. There was no significant correlation between the median model for ESLD score and the hyperemic effect of adenosine (R = 0.10). At 1 year, 13 patients had died (92% noncardiac in etiology), and patients with FFR ≤0.80 had significantly higher all-cause mortality (73% vs 17%, p = 0.001. In conclusion, in patients with ESLD who underwent orthotopic liver transplantation evaluation, P_v has minimal impact on FFR, and the hyperemic effect of adenosine is preserved. Furthermore, even in patients with the predominantly angiographically-intermediate disease, FFR ≤0.80 was an independent predictor of all-cause mortality.

Benefits of both physical assessment and electronic health record review to assess frailty prior to heart transplant

INTRODUCTION

Frailty status affects outcomes after heart transplantation, but the optimal way to assess frailty prior to transplant remains unknown.

METHODS

This single-center, observational study assessed 44 heart transplant candidates for frailty using three methods. The Short Physical Performance Battery (SPPB) and Fried Frailty Phenotype (FFP) were used as two physical assessments of frailty. The Frailty Risk Score (FRS) was used as a chart-review based assessment measuring 20 different biopsychosocial and functional components, including biomarkers, depression, cognitive impairment, and sleep.

RESULTS

We determined the correlation between FRS, SPPB, and FFP and how each correlated with clinical outcomes. Of 44 participants, mean age was 60 years. FRS correlated with SPPB and FFP (P = .043, P < .001, respectively). Higher frailty as measured by SPPB and FRS was significantly associated with lack of achieving waitlist status (P = .022; P = .002) and not being transplanted (P = .026; P = .008). Higher frailty by SPPB and FFP was also associated with mortality (P = .010; P = .025).

CONCLUSION

SPPB and chart-review FRS showed potential for predicting waitlist and transplant status of heart transplant candidates, while SPPB and FFP were associated with mortality. Additional studies may serve to validate these observations.

Implementation and Outcomes of an Urban Mobile Adult Extracorporeal Life Support Program

Objective

Methods

Results

Conclusions

Impact of Transitioning from In-Person to Virtual Heart Transplantation Selection Committee Meetings: An Observational Study (Preprint)

Background

Heart transplant selection committee meetings have transitioned from in-person to remote video meetings during the COVID-19 pandemic, but how this impacts committee members and patient outcomes is unknown.

Objective

The aim of this study is to determine the perceived impact of remote video transplant selection meetings on usability and patient care and to measure patient selection outcomes during the transition period from in-person to virtual meetings.

Methods

A 35-item anonymous survey was developed and distributed electronically to the heart transplant selection committee. We reviewed medical records to compare the outcomes of patients presented at in-person meetings (January-March 2020) to those presented during video meetings (March-June 2020).

Results

Among 83 committee members queried, 50 were regular attendees. Of the 50 regular attendees, 24 (48%) were physicians and 26 (52%) were nonphysicians, including nurses, social workers, and coordinators; 46 responses were received, 23 (50%) from physicians and 23 (50%) from nonphysicians, with 41 responses fully completed. Overall, respondents were satisfied with the videoconference format and felt that video meetings did not impact patient care and were an acceptable alternative to in-person meetings. However, 54% (22/41) preferred in-person meetings, with 71% (15/21) of nonphysicians preferring in-person meetings compared to only 35% (7/20) of physicians (P=.02). Of the 46 new patient evaluations presented, there was a statistically nonsignificant trend toward fewer patients initially declined at video meetings compared with in-person meetings (6/24, 25% compared to 10/22, 45%; P=.32).

Conclusions

The transition from in-person to video heart transplant selection committee meetings was well-received and did not appear to affect committee members’ perceived ability to deliver patient care. Patient selection outcomes were similar between meeting modalities.

Evaluating Factors of Greater Patient Satisfaction with Outpatient Cardiology Telehealth Visits During the COVID-19 Pandemic

Background

The impact of telehealth on cardiovascular care during the COVID-19 pandemic on patient satisfaction and factors associated with satisfaction are not well characterized.

Methods

We conducted a nonrandomized, prospective cross-sectional survey study for outpatient telehealth cardiovascular visits over a 169-day period utilizing a validated telehealth usability questionnaire. For each variable, patients were divided into 2 groups—1 with scores above the median, labeled “greater satisfaction,” and the other with scores below the median, labeled “less satisfaction.”

Results

A total of 13,913 outpatient telehealth encounters were successfully completed during the study period. A total of 7327 unique patients were identified and received a survey invitation; 5993 (81.8%) patients opened the invitation, and 1034 (14.1%) patients consented and completed the survey. Overall mean and median scores were 3.15 (standard deviation 0.74) and 3.37 (interquartile range 2.73–3.68) (maximum score 4.00). Greater satisfaction was noted among younger patients (mean age 63.3 ± 14.0 years, P = .005), female gender (46.3%, P = .007), non-White ethnicity (24.2% P = .006), self-identified early adopters and innovators of new technology (49.8%, P < .001), 1-way travel time greater than 1 hour (22.3%, P < .001), 1-way travel distance greater than 10 miles (49.0%, P < .001), patients needing child care arrangement (16.4%, P < .001), and history of orthotopic heart transplant (OHT) (5.1%, P = .04).

Conclusion

Patients reported overall satisfaction with telehealth during the COVID-19 pandemic. Factors associated with patient convenience, along with female gender, younger age, and non-White ethnicity, correlated with greater satisfaction. Cardiovascular comorbidities did not correlate with greater satisfaction except for OHT. Further research into the impact of telehealth on patient satisfaction, safety, and clinical outcomes is needed.

Change in Invasively Measured Mean Pulmonary Artery Pressure After Transcatheter Mitral Valve Repair Is Associated With Heart Failure Readmission

Background

Pre-existing pulmonary hypertension is associated with poor outcomes after transcatheter mitral valve repair (TMVr) for mitral regurgitation (MR). However, the impact of an immediate change in mean pulmonary artery pressure (ΔmPAP) following TMVr on outcomes is unknown.

Methods

Patients who underwent TMVr from December 2015 to February 18, 2020 at our institution for symptomatic 3-4+ MR and who had invasive hemodynamics measured immediately pre- and post-TMVR were included. Multivariate Cox regression analysis was performed to examine the association of ΔmPAP (post-TMVr - pre-TMVr mPAP) with the primary endpoint of heart failure (HF) readmission at 1 year. Secondary endpoints included all-cause mortality and the composite endpoint of HF readmission or all-cause mortality at 1 year.

Results

Among 55 patients, 55% were men, mean age was 72 ± 14.2 years, and mean ΔmPAP was -1.4 ± 8.2 mm Hg. Overall, HF readmission occurred in 14 (25%), death in 10 (18%), and the composite endpoint in 20 (36%) patients. In multivariable analyses, higher ΔmPAP was significantly associated with HF readmission (hazard ratio (HR) = 1.10, 95% confidence interval (CI): 1.00 - 1.21; P = 0.04). ΔmPAP was not associated with death (HR = 1.04, 95% CI: 0.96 - 1.14; P = 0.33), though there was a numerical but statistically non-significant trend towards the composite endpoint (HR = 1.06, 95% CI: 1.00 - 1.13; P = 0.06) driven by HF readmission.

Conclusion

Higher ΔmPAP immediately following TMVr was associated with increased HF readmission at 1 year. Larger prospective studies are needed to validate these data and further explore the utility of ΔmPAP as a novel hemodynamic parameter to predict post-TMVR outcomes.

Post-Acute COVID-19 Syndrome and the cardiovascular system: What is known?

Post-Acute COVID-19 Syndrome (PACS) is defined by persistent symptoms >3-4 weeks after onset of COVID-19. The mechanism of these persistent symptoms is distinct from acute COVID-19 although not completely understood despite the high incidence of PACS. Cardiovascular symptoms such as chest pain and palpitations commonly occur in PACS, but the underlying cause of symptoms is infrequently known. While autopsy studies have shown that the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) rarely causes direct myocardial injury, several syndromes such as myocarditis, pericarditis, and Postural Orthostatic Tachycardia Syndrome have been implicated in PACS. Additionally, patients hospitalized with acute COVID-19 who display biomarker evidence of myocardial injury may have underlying coronary artery disease revealed by the physiological stress of SARS-CoV-2 infection and may benefit from medical optimization. We review what is known about PACS and the cardiovascular system and propose a framework for evaluation and management of related symptoms.

Nidogen-1 Mitigates Ischemia and Promotes Tissue Survival and Regeneration

Ischemia impacts multiple organ systems and is the major cause of morbidity and mortality in the developed world. Ischemia disrupts tissue homeostasis, driving cell death, and damages tissue structure integrity. Strategies to heal organs, like the infarcted heart, or to replace cells, as done in pancreatic islet β-cell transplantations, are often hindered by ischemic conditions. Here, it is discovered that the basement membrane glycoprotein nidogen-1 attenuates the apoptotic effect of hypoxia in cardiomyocytes and pancreatic β-cells via the αvβ3 integrin and beneficially modulates immune responses in vitro. It is shown that nidogen-1 significantly increases heart function and angiogenesis, while reducing fibrosis, in a mouse postmyocardial infarction model. These results demonstrate the protective and regenerative potential of nidogen-1 in ischemic conditions.

1109. Valgancyclovir Dosing for Cytomegalovirus Prophylaxis in Heart Transplant Recipients

Background

Cytomegalovirus (CMV) is one of the most common infections after transplantation and continues to cause significant morbidity and mortality. Current guidelines recommend 3-6 months of post-transplant prophylaxis with 900mg daily of valganciclovir in heart transplant recipients. At our institution, however, the protocol is to use 450mg daily of valganciclovir for 6-12 months for intermediate risk (R+) patients and 900 mg daily for high risk (D+/R-) patients. In this study we aimed to identify underlying patient characteristics associated with detectable viral load above the quantifiable threshold.

Table 1. Comparison of patients with a CMV viral above and below 137.

Methods

We retrospectively reviewed medical records of adult (≥ 18 years) heart transplant recipients with detectable CMV viremia from 2016-2018 resulted during routine clinical screening.

Results

Ninety-seven heart transplant recipients with a detectable CMV viral load were identified. Of those, 38 (37.2%) had a quantifiable viral load above the 137 IU/mL threshold. When compared to the individuals with a detectable viral load below the threshold (< 137 IU/mL), they had similar age at time of transplant, increased likelihood of donor/recipient CMV IgG mismatch, and were more frequently on 900mg daily of prophylaxis at time of viremia. Of the individuals with CMV DNAemia above the threshold, the median time to viremia was 271.4 days and the median peak viral load was 701 IU/mL. When limiting analysis to only recipients who were CMV IgG positive, patients with viremia had similar age and more likely to be on 900mg daily of valganciclovir as prophylaxis when compared to individuals with CMV viremia < 137 IU/mL. When comparing CMV D+/R- patients, age and rates of 900mg valganciclovir as prophylaxis were similar (Table 1).

Conclusion

We found that despite receipt of CMV prophylaxis, an appreciable number of both R+ and D-/R+ heart transplant recipients developed breakthrough DNAemia despite being on prophylaxis of valganciclovir as recommended by guidelines. Despite receipt of the higher 900 mg daily dose, high risk patients had higher rates of breakthrough DNAemia at our institution compared with R+ intermediate risk patients. More research is needed to evaluate the optimal dose and duration for prophylaxis in heart transplant patients against CMV.

Disclosures

All Authors: No reported disclosures

Angiotensin Converting Enzyme Inhibitor and Angiotensin II Receptor Blocker Use Among Outpatients Diagnosed With COVID-19

Coronavirus disease 2019 (COVID-19) is a viral pandemic precipitated by the severe acute respiratory syndrome coronavirus 2. Since previous reports suggested that viral entry into cells may involve angiotensin converting enzyme 2, there has been growing concern that angiotensin converting enzyme inhibitor (ACEI) and angiotensin II receptor blocker (ARB) use may exacerbate the disease severity. In this retrospective, single-center US study of adult patients diagnosed with COVID-19, we evaluated the association of ACEI/ARB use with hospital admission. Secondary outcomes included: ICU admission, mechanical ventilation, length of hospital stay, use of inotropes, and all-cause mortality. Propensity score matching was performed to account for potential confounders. Among 590 unmatched patients diagnosed with COVID-19, 78 patients were receiving ACEI/ARB (median age 63 years and 59.7% male) and 512 patients were non-users (median age 42 years and 47.1% male). In the propensity matched population, multivariate logistic regression analysis adjusting for age, gender and comorbidities demonstrated that ACEI/ARB use was not associated with hospital admission (OR 1.2, 95%CI 0.5 to 2.7, p = 0.652). CAD and CKD/end stage renal disease [ESRD] remained independently associated with admission to hospital. All-cause mortality, ICU stay, need for ventilation, and inotrope use was not significantly different between the 2 study groups. In conclusion, among patients who were diagnosed with COVID-19, ACEI/ARB use was not associated with increased risk of hospital admission.

Discovery of non-HLA antibodies associated with cardiac allograft rejection and development and validation of a non-HLA antigen multiplex panel: From bench to bedside

We analyzed humoral immune responses to nonhuman leukocyte antigen (HLA) after cardiac transplantation to identify antibodies associated with allograft rejection. Protein microarray identified 366 non-HLA antibodies (>1.5 fold, P < .5) from a discovery cohort of HLA antibody-negative, endothelial cell crossmatch-positive sera obtained from 12 cardiac allograft recipients at the time of biopsy-proven rejection. From these, 19 plasma membrane proteins and 10 autoantigens identified from gene ontology analysis were combined with 48 proteins identified through literature search to generate a multiplex bead array. Longitudinal sera from a multicenter cohort of adult cardiac allograft recipients (samples: n = 477 no rejection; n = 69 rejection) identified 18 non-HLA antibodies associated with rejection (P < .1) including 4 newly identified non-HLA antigenic targets (DEXI, EMCN, LPHN1, and SSB). CART analysis showed 5/18 non-HLA antibodies distinguished rejection vs nonrejection. Antibodies to 4/18 non-HLA antigens synergize with HLA donor-specific antibodies and significantly increase the odds of rejection (P < .1). The non-HLA panel was validated using an independent adult cardiac transplant cohort (n = 21 no rejection; n = 42 rejection, >1R) with an area under the curve of 0.87 (P < .05) with 92.86% sensitivity and 66.67% specificity. We conclude that multiplex bead array assessment of non-HLA antibodies identifies cardiac transplant recipients at risk of rejection.

Implementation of a Telemedicine Clinic in the Covid-19 Era

Background

COVID-19 has drastically altered the delivery of medical care in the United States and beyond. Healthcare providers have been forced to rapidly innovate to mitigate the spread of infection and maintain social distancing. Telemedicine allows for the continuation of vital patient care while decreasing the risk of virus transmission.

Objective

We conducted a survey to assess the satisfaction of both patients and providers with rapid implementation of an electronic medical record (EMR) based video visit system.

Methods

A survey hyperlink was distributed through EMR messages to patients and emails to providers.

Results

74/376 patients (19.7%) and 8/10 (80%) providers completed the survey. The population consisted of advanced heart failure (n = 37, 50%), mechanical circulatory support (n = 4, 5.4%), transplant (n = 19, 25.7%) and general cardiology (n = 14, 18.9%) patients and their respective providers. The patient survey consisted of validated survey questions to assess patient and provider perceptions. Patients were 69.7% male with a mean age of 65. 74% of the patients consider themselves early adopters or innovators with new technology. 85% of surveyed patients believed that telemedicine is simple to use and easy to learn. 77% felt the telemedicine system interface was of good quality, 88% believed it allows for good interaction with the provider, 95% believed it protects both patients and providers by limiting exposure to COVID-19, 83% were overall satisfied with this telemedicine system and would use it again. 75% of providers reported no telemedicine experience prior to COVID-19. Notably, 100% of physicians consider themselves early adopters or innovators with new technology. 87.5% deemed their patients highly complex. 100 % of providers felt that telemedicine is useful for their job and 87.5% felt that their job would be difficult to perform without it, 27.5% believed video visits save and reduce time spent on unproductive activities, and allow accomplishing more work and tasks more quickly, 87.5% believe the system is easy to use overall, 100% agree it enhances providers’ and patients’ safety during COVID-19.

Conclusion

Patients reported high level of satisfaction with video visits and interaction with their providers as well as with the ease of use and convenience of telemedicine appointments. Providers found the telemedicine system easy to use and useful for their job, but many believe there is room for improvement with respect to time saving measures.

Relapsing Polychondritis Requiring Orthotopic Heart Transplant Despite Coronary Artery Bypass and Surgical Aortic Valve Replacement

A 32-year-old man with a history of relapsing polychondritis presented with acute coronary syndrome due to aortitis with ostial coronary artery involvement from his underlying autoimmune condition. Concomitant aortic insufficiency with ostial coronary lesions is a rare complication of relapsing polychondritis, requiring a multidisciplinary team approach for management. (Level of Difficulty: Advanced.)

Heart transplantation in the early phase of the COVID-19 pandemic: A single-center case series

The infectious disease coronavirus disease 2019 (COVID‐19) was declared a pandemic by the World Health Organization in March 2020. The impact of COVID‐19 on solid organ transplantations, including heart transplantation, is currently unclear. Many transplant programs have been forced to swiftly re‐evaluate and adapt their practices, leading to a marked decrease in transplants performed. This trend has been due to various factors, including increased donor COVID‐19 screening scrutiny and recipient waiting list management in anticipation of COVID‐19 critical care surge capacity planning. In the face of these unknown variables, determining when and how to proceed with transplantation in our population of patients with end‐stage cardiomyopathies is challenging. Here, we describe our center's experience with orthotopic heart transplantation (OHT) in one of the country's pandemic epicenters, where we performed eight OHTs in the first 2 months after community spread began in late February 2020.

COVID-19 in a high-risk dual heart and kidney transplant recipient

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is rapidly infecting people worldwide, resulting in the infectious disease coronavirus disease 19 (COVID-19) that has been declared a pandemic. Much remains unknown about COVID-19, including its effects on solid organ transplant (SOT) recipients. Given their immunosuppressed state, SOT recipients are presumed to be at high risk of complications with viral infections such as SARS-CoV-2. Limited case reports in single SOT recipients, however, have not suggested a particularly severe course in this population. In this report, we present a dual-organ (heart/kidney) transplant recipient who was found to have COVID-19 and, despite the presence of a number of risk factors for poor outcomes, had a relatively mild clinical course.

Trends in utilization, mortality, and resource use after implantation of left ventricular assist devices in the United States

OBJECTIVES

Adoption of implantable left ventricular assist devices has dramatically improved survival and quality of life in suitable patients with end-stage heart failure. In the era of value-based healthcare delivery, assessment of clinical outcomes and resource use associated with left ventricular assist devices is warranted.

METHODS

Adult patients undergoing left ventricular assist device implantation from 2008 to 2016 were identified using the National Inpatient Sample. Hospitals were designated as low-volume, medium-volume, or high-volume institutions based on annual institutional left ventricular assist device case volume. Multivariable logistic regression was used to evaluate adjusted odds of mortality across left ventricular assist device volume tertiles.

RESULTS

Over the study period, an estimated 23,972 patients underwent left ventricular assist device implantation with an approximately 3-fold increase in the number of annual left ventricular assist device implantations performed (P for trend <.001). In-hospital mortality in patients with left ventricular assist devices decreased from 19.6% in 2008 to 8.1% in 2016 (P for trend <.001) and was higher at low-volume institutions compared with high-volume institutions (12.0% vs 9.2%, P < .001). Although the overall adjusted mortality was higher at low-volume compared with high-volume institutions (adjusted odds ratio, 1.66; 95% confidence interval, 1.28-2.15), this discrepancy was only significant for 2008 and 2009 (low-volume 2008 adjusted odds ratio, 5.5; 95% confidence interval, 1.9-15.8; low-volume 2009 adjusted odds ratio, 2.3; 95% confidence interval, 1.4-3.8).

CONCLUSIONS

Left ventricular assist device use has rapidly increased in the United States with a concomitant reduction in mortality and morbidity. With maturation of left ventricular assist device technology and increasing experience, volume-related variation in mortality and resource use has diminished. Whether the apparent uniformity in outcomes is related to patient selection or hospital quality deserves further investigation.

Influenza A (H3N2) Induced Fulminant Myocarditis Requiring Mechanical Circulatory Support

The authors report a case of fulminant myocarditis from an influenza A (H3N2) infection in a healthy individual who experienced cardiac arrest requiring extracorporeal membrane oxygenation (ECMO). The case highlights the management of complications arising from the use of ECMO including differential hypoxia and left ventricular overload requiring left ventricular venting. (Level of Difficulty: Beginner.).

Monomorphic Ventricular Arrhythmias in Athletes

Ventricular arrhythmias are challenging to manage in athletes with concern for an elevated risk of sudden cardiac death (SCD) during sports competition. Monomorphic ventricular arrhythmias (MMVA), while often benign in athletes with a structurally normal heart, are also associated with a unique subset of idiopathic and malignant substrates that must be clearly defined. A comprehensive evaluation for structural and/or electrical heart disease is required in order to exclude cardiac conditions that increase risk of SCD with exercise, such as hypertrophic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy. Unique issues for physicians who manage this population include navigating athletes through the decision of whether they can safely continue their chosen sport. In the absence of structural heart disease, therapies such as radiofrequency catheter ablation are very effective for certain arrhythmias and may allow for return to competitive sports participation. In this comprehensive review, we summarise the recommendations for evaluating and managing athletes with MMVA.