Modification of a Transvalvular Microaxial Flow Pump for Instantaneous Determination of Native Cardiac Output and Volume.

BACKGROUND: The current Impella cardiopulmonary (CP) pump, used for mechanical circulatory support in patients with cardiogenic shock (CS), cannot assess native cardiac output (CO) and left ventricular (LV) volumes. These data are valuable in facilitating device management and weaning. Admittance technology allows for accurate assessment of cardiac chamber volumes. OBJECTIVES: This study tested the ability to engineer admittance electrodes onto an existing Impella CP pump to assess total and native CO as well as LV chamber volumes in an instantaneous manner. METHODS: Impella CP pumps were fitted with 4 admittance electrodes and were placed in the LVs of adult swine (n = 9) that were subjected to 3 different hemodynamic conditions, including Impella CP speed adjustments, administration of escalating doses of dobutamine and microsphere injections into the left main artery to result in cardiac injury. CO, according to admittance electrodes, was calculated from LV volumes and heart rate. In addition, CO was calculated in each instance via thermodilution, continuous CO measurement, the Fick principle, and aortic velocity-time integral by means of echocardiography. RESULTS: Modified Impella CP pumps were placed in swine LVs successfully. CO, as determined by admittance electrodes, was similar by trend to other methods of CO assessment. It was corrected for pump speed to calculate native CO, and calculated LV chamber volumes trended as expected in each experimental protocol. CONCLUSIONS: We report, for the first time, that an Impella CP pump can be fitted with admittance electrodes and used to determine total and native CO in various hemodynamic situations. CONDENSED ABSTRACT: Transvalvular mechanical circulatory support devices such as the Impella CP do not have the ability to provide real-time information on native cardiac output (CO) and left ventricular (LV) volumes. This information is critical in device management and in weaning in patients with cardiogenic shock. We demonstrate, for the first time, that Impella CP pumps coupled with admittance electrodes are able to determine native CO and LV chamber volumes in multiple hemodynamic situations such as Impella pump speed adjustments, escalating dobutamine administration and cardiac injury from microsphere injection.

The Accuracy of Initial U.S. Heart Transplant Candidate Rankings.

BACKGROUND: The U.S. heart allocation system ranks candidates with only 6 treatment-based categorical "statuses" and ignores many objective patient characteristics. OBJECTIVES: This study sought to determine the effectiveness of the standard 6-status ranking system and several novel prediction models in identifying the most urgent heart transplant candidates. METHODS: The primary outcome was death before receipt of a heart transplant. The accuracy of the 6-status system was evaluated using Harrell's C-index and log-rank tests of Kaplan-Meier estimated survival by status for candidates listed postpolicy (November 2018 to March 2020) in the Scientific Registry of Transplant Recipients data set. The authors then developed Cox proportional hazards models and random survival forest models using prepolicy data (2010-2017). The predictor variables included age, diagnosis, laboratory measurements, hemodynamics, and supportive treatment at the time of listing. The performance of these models was compared with the candidate's 6-status ranking in the postpolicy data. RESULTS: Since policy implementation, the 6-status ranking at listing has had moderate ability to rank-order candidates (C-index: 0.67). Statuses 4 and 6 had no significant difference in survival (P = 0.80), and status 5 had lower survival than status 4 (P < 0.001). Novel multivariable prediction models derived with prepolicy data ranked candidates correctly more often than the 6-status rankings (Cox proportional hazards model C-index: 0.76; random survival forest model C-index: 0.74). Objective physiologic measurements, such as glomerular filtration rate, had high variable importance. CONCLUSIONS: The treatment-based 6-status heart allocation system has only moderate ability to rank-order candidates by medical urgency. Predictive models that incorporate physiologic measurements can more effectively rank-order heart transplant candidates by urgency.

Multiparametric Cardiac Magnetic Resonance Imaging Detects Altered Myocardial Tissue and Function in Heart Transplantation Recipients Monitored for Cardiac Allograft Vasculopathy.

BACKGROUND: Cardiac allograft vasculopathy (CAV) is a complication beyond the first-year post-heart transplantation (HTx). We aimed to test the utility of cardiac magnetic resonance (CMR) to detect functional/structural changes in HTx recipients with CAV. METHODS: Seventy-seven prospectively recruited HTx recipients beyond the first-year post-HTx and 18 healthy controls underwent CMR, including cine imaging of ventricular function and T1- and T2-mapping to assess myocardial tissue changes. Data analysis included quantification of global cardiac function and regional T2, T1 and extracellular volume based on the 16-segment model. International Society for Heart and Lung Transplantation criteria was used to adjudicate CAV grade (0-3) based on coronary angiography. RESULTS: The majority of HTx recipients (73%) presented with CAV (1: n = 42, 2/3: n = 14, 0: n = 21). Global and segmental T2 (49.5 ± 3.4 ms vs 50.6 ± 3.4 ms, p < 0.001;16/16 segments) were significantly elevated in CAV-0 compared to controls. When comparing CAV-2/3 to CAV-1, global and segmental T2 were significantly increased (53.6 ± 3.2 ms vs. 50.6 ± 2.9 ms, p < 0.001; 16/16 segments) and left ventricular ejection fraction was significantly decreased (54 ± 9% vs. 59 ± 9%, p < 0.05). No global, structural, or functional differences were seen between CAV-0 and CAV-1. CONCLUSIONS: Transplanted hearts display functional and structural alteration compared to native hearts, even in those without evidence of macrovasculopathy (CAV-0). In addition, CMR tissue parameters were sensitive to changes in CAV-1 vs. 2/3 (mild vs. moderate/severe). Further studies are warranted to evaluate the diagnostic value of CMR for the detection and classification of CAV.

Hyponatremia Is a Powerful Predictor of Poor Prognosis in Left Ventricular Assist Device Patients.

Serum sodium is an established prognostic marker in heart failure (HF) patients and is associated with an increased risk of morbidity and mortality. We sought to study the prognostic value of serum sodium in left ventricular assist device (LVAD) patients and whether hyponatremia reflects worsening HF or an alternative mechanism. We identified HF patients that underwent LVAD implantation between 2008 and 2019. Hyponatremia was defined as Na ≤134 mEq/L at 3 months after implantation. We assessed for differences in hyponatremia before and after LVAD implantation. We also evaluated the association of hyponatremia with all-cause mortality and recurrent HF hospitalizations. There were 342 eligible LVAD patients with a sodium value at 3 months. Among them, there was a significant improvement in serum sodium after LVAD implantation compared to preoperatively (137.2 vs. 134.7 mEq/L, P < 0.0001). Patients with and without hyponatremia had no significant differences in echocardiographic and hemodynamic measurements. In a multivariate analysis, hyponatremia was associated with a markedly increased risk of all-cause mortality (HR 3.69, 95% CI, 1.93-7.05, P < 0.001) when accounting for age, gender, co-morbidities, use of loop diuretics, and B-type natriuretic peptide levels. Hyponatremia was also significantly associated with recurrent HF hospitalizations (HR 2.11, 95% CI, 1.02-4.37, P = 0.04). Hyponatremia in LVAD patients is associated with significantly higher risk of all-cause mortality and recurrent HF hospitalizations. Hyponatremia may be a marker of ongoing neurohormonal activation that is more sensitive than other lab values, echocardiography parameters, and hemodynamic measurements.

Cardiac complications of COVID-19: Incidence and outcomes.

BACKGROUND: Coronavirus disease-2019 (COVID-19) has been associated with pre-existing cardiac conditions as well as cardiovascular complications. The incidence rates of cardiac complications, age, and gender differences in this population are unknown. OBJECTIVES: We wanted to study the incidence of cardiac complications and mortality in patients with COVID-19. METHODS: Data from the TriNetX COVID-19 global research network platform was used to identify COVID-19 patients. We compared patients with and without cardiac complications in patients with COVID-19 and obtained survival data. RESULTS: The final cohort was composed of 81,844 patients with COVID-19. Cardiac complications occurred in 9.3% of patients as follows: acute coronary syndromes in 1.3%, heart failure in 4.4%, atrial fibrillation in 4.5%, sinus bradycardia 1.9%, ventricular tachycardia in 0.5% and complete heart block in 0.01%. Mortality was significantly higher in patients with the cardiac complications mentioned (20%) than in those without them (2.9%) (odds ratio 7.2, 95% CI, 6.7-7.7; p < 0.0001). Older males seem to have higher incidence of cardiac complications and mortality. CONCLUSIONS: Patients with COVID-19 who have cardiac complications have a higher risk of mortality when compared to those without cardiac complications.

A Comprehensive Review of Calcineurin Inhibitors Used for Immunosuppression in Cardiac Transplantation.

Calcineurin inhibitors (CNIs) have been the foundation of immunosuppression in solid organ transplantation since the 1980s. Cyclosporine A (CSA), the first in class, was identified as the metabolite of the soil fungus Tolypocladium inflatum Gams as part of a larger program of screening for naturally occurring fungal metabolites with biologic activity in the 1970s. Significant immunosuppressive effects were discovered and consequently CSA was trialed as an immunosuppressant in renal transplantation. This initial success led to its widespread study and adoption in solid organ transplantation. This novel agent yielded significant improvements in both 1 year and longer-term allograft and patient survival. Subsequently, a similar and more potent CNI, tacrolimus was developed. Today, it is the principal CNI used for prevention of allograft rejection. Like all other immunosuppressives, the benefits of CNIs are counterbalanced by side effects and complications resulting from drug toxicity. This chapter comprehensively reviews the clinical use of CNIs in cardiac transplantation.

Variability in Blood Pressure Assessment in Patients Supported with the HeartMate 3TM.

Targeted blood pressure (BP) control is a goal of left ventricular assist device medical management, but the interpretation of values obtained from noninvasive instruments is challenging. In the MOMENTUM 3 Continued Access Protocol, paired BP values in HeartMate 3 (HM3) patients were compared from arterial (A)-line and Doppler opening pressure (DOP) (319 readings in 261 patients) and A-line and automated cuff (281 readings in 247 patients). Pearson (R) correlations between A-line mean arterial (MAP) and systolic blood pressures (SBP) were compared with DOP and cuff measures according to the presence (>1 pulse in 5 seconds) or absence of a palpable radial pulse. There were only moderate correlations between A-line and noninvasive measurements of SBP (DOP R = 0.58; cuff R = 0.47) and MAP (DOP R = 0.48; cuff R = 0.37). DOP accuracy for MAP estimation, defined as the % of readings within ± 10 mmHg of A-line MAP, decreased from 80% to 33% for DOP ≤ 90 vs. >90 mmHg, and precision also diminished (mean absolute difference [MAD] increased from 6.3 ± 5.6 to 16.1 ± 11.4 mmHg). Across pulse pressures, cuff MAPs were within ±10 mmHg of A-line 62.9%-68.8% of measures and MADs were negligible. The presence of a palpable pulse reduced the accuracy and precision of the DOP-MAP estimation but did not impact cuff-MAP accuracy or precision. In summary, DOP may overestimate MAP in some patients on HM3 support. Simultaneous use of DOP and automated cuff and radial pulse may be needed to guide antihypertensive medication titration in outpatients on HM3 support.

Between-center variation in high-priority listing status under the new heart allocation policy.

Under the new US heart allocation policy, transplant centers listed significantly more candidates at high priority statuses (Status 1 and 2) with mechanical circulatory support devices than expected. We determined whether the practice change was widespread or concentrated among certain transplant centers. Using data from the Scientific Registry of Transplant Recipients, we used mixed-effect logistic regression to compare the observed listings of adult, heart-alone transplant candidates post-policy (December 2018 to February 2020) to seasonally matched pre-policy cohort (December 2016 to February 2018). US transplant centers (N = 96) listed similar number of candidates in each policy period (4472 vs. 4498) but listed significantly more at high priority status (25.5% vs. 7.0%, p < .001) than expected. Adjusted for candidate characteristics, 91 of 96 (94.8%) centers listed significantly more candidates at high-priority status than expected, with the unexpected increase varying from 4.8% to 50.4% (interquartile range [IQR]: 14.0%-23.3%). Centers in OPOs with highest Status 1A transplant rate pre-policy were significantly more likely to utilize high-priority status under the new policy (OR: 9.73, p = .01). The new heart allocation policy was associated with widespread and significantly variable changes in transplant center practice that may undermine the effectiveness of the new system.

Genomic Context Differs Between Human Dilated Cardiomyopathy and Hypertrophic Cardiomyopathy.

Background Inherited cardiomyopathies display variable penetrance and expression, and a component of phenotypic variation is genetically determined. To evaluate the genetic contribution to this variable expression, we compared protein coding variation in the genomes of those with hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). Methods and Results Nonsynonymous single-nucleotide variants (nsSNVs) were ascertained using whole genome sequencing from familial cases of HCM (n=56) or DCM (n=70) and correlated with echocardiographic information. Focusing on nsSNVs in 102 genes linked to inherited cardiomyopathies, we correlated the number of nsSNVs per person with left ventricular measurements. Principal component analysis and generalized linear models were applied to identify the probability of cardiomyopathy type as it related to the number of nsSNVs in cardiomyopathy genes. The probability of having DCM significantly increased as the number of cardiomyopathy gene nsSNVs per person increased. The increase in nsSNVs in cardiomyopathy genes significantly associated with reduced left ventricular ejection fraction and increased left ventricular diameter for individuals carrying a DCM diagnosis, but not for those with HCM. Resampling was used to identify genes with aberrant cumulative allele frequencies, identifying potential modifier genes for cardiomyopathy. Conclusions Participants with DCM had more nsSNVs per person in cardiomyopathy genes than participants with HCM. The nsSNV burden in cardiomyopathy genes did not correlate with the probability or manifestation of left ventricular measures in HCM. These findings support the concept that increased variation in cardiomyopathy genes creates a genetic background that predisposes to DCM and increased disease severity.

Cardiac transplantation outcomes in patients with amyloid cardiomyopathy.

OBJECTIVE: Amyloid cardiomyopathy (ACM) is a progressive and life-threatening disease caused by abnormal protein deposits within cardiac tissue. The most common forms of ACM are caused by immunoglobulin derived light chains (AL) and transthyretin (TTR). Orthotopic heart transplantation (OHT) remains the definitive treatment for patients with end stage heart failure. In this study, we perform a contemporary multicenter analysis evaluating post OHT survival in patients with ACM. METHODS: We conducted a multicenter analysis of 40,044 adult OHT recipients captured in the United Network for Organ Sharing (UNOS) registry from 1987-2018. Patients were characterized as ACM or non-ACM. Baseline characteristics were obtained, and summary characteristics were calculated. Outcomes of interest included post-transplant survival, infection, treated rejection, and the ability to return to work. Racial differences in OHT survival were also analyzed. Unadjusted associations between ACM and non-ACM survival were determined using the Kaplan-Meier estimations and confounding was addressed using multivariable Cox proportional hazards models. RESULTS: Three hundred ninety-eight patients with a diagnosis of ACM were identified of which 313 underwent heart only OHT. ACM patients were older (61 vs 53; P < .0001) and had a higher proportion of African Americans (30.7% vs 17.6%; P < .0001). Median survival for ACM was 10.2 years vs 12.5 years in non-ACM (P = .01). After adjusting for confounding, ACM patients had a higher likelihood of death post-OHT (HR 1.39 CI: 1.14, 1.70; P = .001). African American ACM patients had a higher likelihood of survival compared to White ACM patients (HR 0.51 CI 0.31-0.85; P = .01). No difference was observed in episodes of treated rejection (OR 0.63 CI 0.23, 1.78; P = .39), hospitalizations for infections (OR 1.24 CI: 0.85, 1.81; P = .26), or likelihood of returning to work for income (OR 1.23 CI: 0.84, 1.80; P = .30). CONCLUSIONS: In this analysis of OHT in ACM, ACM was associated with a higher likelihood of post-OHT mortality. Racial differences in post-OHT were observed with African American patients with ACM having higher likelihood of survival compared to White patients with ACM. No differences were observed in episodes of treated rejection, hospitalization for infection, or likelihood to return to work for income.

Association of cigarette smoking and adverse events in left ventricular assist device patients.

INTRODUCTION: Adverse events (AEs) associated with left ventricular assist devices (LVADs) cause significant morbidity and mortality. Little is known about patient-specific factors that contribute to rates of AEs. The purpose of this study was to assess the association of cigarette smoking history and AEs following LVAD implantation. METHODS: This study was a single-center, observational examination of 355 consecutive patients who underwent continuous-flow LVAD implantation from May 1, 2008 to July 1, 2018. Based on self-report, 348 patients with available data were categorized as never, former, or current smokers. Pre-LVAD implantation baseline characteristics were obtained, and summary characteristics were calculated. Hospitalizations for gastrointestinal bleeds, driveline infections, strokes, pump thromboses, and acute heart failure were evaluated. The Cox proportional hazard model was used to estimate the association of smoking and AE-related hospital admissions. The cumulative incidence competing risk method was used for survival analysis. RESULTS: Current (8.22%, p 0.006) and former (4.75%, p 0.026) smokers had a greater proportion of admissions for pump thrombosis compared to never smokers (2.22%). Former smoking was associated with admission for driveline infection (HR 2.43, CI 1.08-5.46, p 0.03) on multivariate analysis. There were no significant associations between smoking and the other AEs of interest. There was no difference in survival among the three groups. CONCLUSIONS: Smokers had a higher proportion of admissions for pump thrombosis compared to never smokers, and former smoking was associated with admission for driveline infections in patients with LVADs.

Mineralocorticoid Receptor Antagonists: a Comprehensive Review of Finerenone.

PURPOSE OF REVIEW: We aim to review the mechanism of action and safety profile of mineralocorticoid receptor antagonists (MRAs) and discuss the differences between selective and non-selective MRAs. More specifically, finerenone is a new medication that is currently under investigation for its promising cardiovascular and nephrological effects. RECENT FINDINGS: MRAs are well known for their utility in treating heart failure, refractory hypertension, and diverse nephropathies, namely, diabetic nephropathy. As their name denotes, MRAs inhibit the action of aldosterone at the mineralocorticoid receptor, preventing receptor activation. This prevents remodeling, decreases inflammation, and improves proteinuria. There are not significant differences in outcomes between selective and non-selective MRAs. A new selective MRA named finerenone (originally BAY 94-8862) has shown promising results in several trials (ARTS-HF and ARTS-DN) and smaller studies. Finerenone may have a dose-dependent benefit over older MRAs, decreasing rates of albuminuria and levels of BNP and NT-ProBNP without causing a significant increase in serum potassium levels. This medication is not yet approved as it is still in phase 3 clinical trials (FIGARO-DKD and FIDELIO-DKD trials). MRAs are beneficial in several disease states. Newer medications, such as finerenone, should be considered in patients with heart failure and diabetic nephropathy who may benefit from a reduction in albuminuria and BNP/NT-ProBNP. Data surrounding finerenone are limited to date. However, results from ongoing clinical trials, as well as new trials to evaluate use in other pathologies, could validate the implementation of this medication in daily practice.

Practice Changes at U.S. Transplant Centers After the New Adult Heart Allocation Policy.

BACKGROUND: In October 2018, the U.S. heart allocation system expanded the number of priority "status" tiers from 3 to 6 and added cardiogenic shock requirements for some heart transplant candidates listed with specific types of treatments. OBJECTIVES: This study sought to determine the impact of the new policy on the treatment practices of transplant centers. METHODS: Initial listing data on all adult heart candidates listed from December 1, 2017 to April 30, 2019 were collected from the Scientific Registry of Transplant Recipients. The status-qualifying treatments (or exception requests) and hemodynamic values at listing of a post-policy cohort (December 2018 to April 2019) were compared with a seasonally matched pre-policy cohort (December 2017 to April 2018). Candidates in the pre-policy cohort were reclassified into the new priority system statuses by using treatment, diagnosis, and hemodynamics. RESULTS: Comparing the post-policy cohort (N = 1,567) with the pre-policy cohort (N = 1,606), there were significant increases in listings with extracorporeal membrane oxygenation (+1.2%), intra-aortic balloon pumps (+ 4 %), and exceptions (+ 12%). Listings with low-dose inotropes (-18%) and high-dose inotropes (-3%) significantly decreased. The new priority status distribution had more status 2 (+14%) candidates than expected and fewer status 3 (-5%), status 4 (- 4%) and status 6 (-8%) candidates than expected (p values <0.01 for all comparisons). CONCLUSIONS: After implementation of the new heart allocation policy, transplant centers listed more candidates with extracorporeal membrane oxygenation, intra-aortic balloon pumps, and exception requests and fewer candidates with inotrope therapy than expected, thus leading to significantly more high-priority status listings than anticipated. If these early trends persist, the new allocation system may not function as intended.

The Role of Anticoagulation in COVID-19-Induced Hypercoagulability.

PURPOSE OF REVIEW: We aim to provide a comprehensive analysis of hypercoagulability in individuals affected by COVID-19. Our goal is to describe the hypercoagulable state related to the infection and provide guidance regarding the possible benefits of anti-coagulation with the support of evidence from current literature. RECENT FINDINGS: The incidence of thrombotic disease in individuals affected by COVID-19 is reported as high as 31%. A significant mortality benefit has been observed with the use of therapeutic anticoagulation in high-risk individuals. Literature supports the use of scoring systems, such as the sepsis-induced coagulopathy score, to risk-stratify individuals who might benefit from anticoagulation. COVID-19-induced hypercoagulability has been demonstrated to play a significant role in overall COVID-19 outcomes. Current literature shows promising evidence with the use of therapeutic anticoagulation in high-risk individuals. Further studies are needed to better analyze the risks and benefits of anticoagulation in this specific patient population.

Outcomes in Patients with COVID-19 Infection Taking ACEI/ARB.

PURPOSE OF REVIEW: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus responsible for the aggressive coronavirus disease (COVID-19) pandemic. Recently, investigators have stipulated that COVID-19 patients receiving angiotensin-converting-enzyme inhibitors (ACEI) may be subject to poorer outcomes. This editorial presents the available evidence to guide treatment practices during this pandemic. RECENT FINDINGS: Recent studies from Wuhan cohorts provide valuable information about COVID-19. A cohort with 52 critically ill patients revealed cardiac injury in 12% of patients. Worse outcomes appear to be more prevalent in patients with hypertension and diabetes mellitus (DM), possibly due to overexpression of angiotensin-converting enzyme 2 (ACE2) receptor in airway alveolar epithelial cells. Investigators suspect that SARS-CoV-2 uses the ACE2 receptor to enter the lungs in a mechanism similar to SARS-CoV. Several hypotheses have been proposed to date regarding the net effect of ACEI/ARB on COVID-19 infections. Positive effects include ACE2 receptor blockade, disabling viral entry into the heart and lungs, and an overall decrease in inflammation secondary to ACEI/ARB. Negative effects include a possible retrograde feedback mechanism, by which ACE2 receptors are upregulated. Even though physiological models of SARS-CoV infection show a theoretical benefit of ACEI/ARB, these findings cannot be extrapolated to SARS-CoV-2 causing COVID-19. Major cardiology scientific associations, including ACC, HFSA, AHA, and ESC Hypertension Council, have rejected these correlation hypotheses. After an extensive literature review, we conclude that there is no significant evidence to support an association for now, but given the rapid evolvement of this pandemic, findings may change.

Prognostic Value of Myocardial Extracellular Volume Fraction and T2-mapping in Heart Transplant Patients.

OBJECTIVES: The purpose of this study was to examine prognostic value of T1- and T2-mapping techniques in heart transplant patients. BACKGROUND: Myocardial characterization using T2 mapping (evaluation of edema/inflammation) and pre- and post-gadolinium contrast T1 mapping (calculation of extracellular volume fraction [ECV] for assessment of interstitial expansion/fibrosis) are emerging modalities that have been investigated in various cardiomyopathies. METHODS: A total of 99 heart transplant patients underwent the magnetic resonance imaging (MRI) scans including T1- (n = 90) and T2-mapping (n = 79) techniques. Relevant clinical characteristics, MRI parameters including late gadolinium enhancement (LGE), and invasive hemodynamics were collected. Median clinical follow-up duration after the baseline scan was 2.4 to 3.5 years. Clinical outcomes include cardiac events (cardiac death, myocardial infarction, coronary revascularization, and heart failure hospitalization), noncardiac death and noncardiac hospitalization. RESULTS: Overall, the global native T1, postcontrast T1, ECV, and T2 were 1,030 ± 56 ms, 458 ± 84 ms, 27 ± 4% and 50 ± 4 ms, respectively. Top-tercile-range ECV (ECV >29%) independently predicted adverse clinical outcomes compared with bottom-tercile-range ECV (ECV <25%) (hazard ratio [HR]: 2.87; 95% confidence interval [CI]: 1.07 to 7.68; p = 0.04) in a multivariable model with left ventricular end-systolic volume and LGE. Higher T2 (T2 ≥50.2 ms) independently predicted adverse clinical outcomes (HR: 3.01; 95% CI: 1.39 to 6.54; p = 0.005) after adjustment for left ventricular ejection fraction, left ventricular end-systolic volume, and LGE. Additionally, higher T2 (T2 ≥50.2 ms) also independently predicted cardiac events (HR: 4.92; CI: 1.60 to 15.14; p = 0.005) in a multivariable model with left ventricular ejection fraction. CONCLUSIONS: MRI-derived myocardial ECV and T2 mapping in heart transplant patients were independently associated with cardiac and noncardiac outcomes. Our findings highlight the need for larger prospective studies.

Evaluating Biventricular Myocardial Velocity and Interventricular Dyssynchrony in Adult Patients During the First Year After Heart Transplantation.

BACKGROUND: Magnetic resonance tissue phase mapping (TPM) measures three-directional myocardial velocities of the left and right ventricle (LV, RV). This noninvasive technique may supplement endomyocardial biopsy (EMB) in monitoring grafts post-heart transplantation (HTx). PURPOSE: To assess biventricular myocardial velocity alterations in grafts and investigate the relationship between velocities and acute cellular rejection (ACR) episodes. STUDY TYPE: Prospective. SUBJECTS: Twenty-seven patients within 1 year post-HTx (49 ± 13 years, 19 M) and 18 age-matched controls (49 ± 15 years, 12 M). FIELD STRENGTH/SEQUENCE: 1.5T, 2D balanced steady-state free precession, and TPM. ASSESSMENT: Ventricular function: end-diastolic and end-systolic volumes, stroke volumes, ejection fraction (EF), and myocardial mass. TPM velocities: peak-systolic and peak-diastolic velocities, cardiac twist, and interventricular dyssynchrony. ACR rejection episodes: International Society for Heart and Lung Transplantation grading of EMB specimens. STATISTICAL TESTS: The Lilliefors test for normality, unpaired t-tests, and Wilcoxon rank-sum tests for normally and nonnormally distributed data, respectively, were used, as well as multivariate regression for confounding variables and Pearson's correlation for associations between TPM velocities and global function. RESULTS: Compared to controls, HTx patients demonstrated reduced biventricular systolic longitudinal velocities (LV: 5.2 ± 2.1 vs. 4.0 ± 1.5 cm/s, P < 0.05; RV: 4.2 ± 1.3 vs. 3.1 ± 1.2 cm/s, P < 0.01). Correlation analysis revealed significant positive relationships for biventricular EF with radial peak velocities of the same ventricle in both systole and diastole (LV systole: r = 0.48, P < 0.01; LV diastole: r = 0.28, P < 0.05; RV systole: r = 0.35, P < 0.01; RV diastole: r = 0.36, P < 0.01). Segmentally, longitudinal velocities were impaired in 7/16 LV segments and 5/10 RV segments in systole and 7/10 RV segments in diastole. TPM analysis in studies with >4 preceding ACR episodes showed globally reduced RV and LV systolic radial velocity, and segmentally reduced radial and longitudinal systolic velocities. DATA CONCLUSION: Biventricular global and segmental velocities were reduced in HTx patients. Patients with >4 rejection episodes showed reduced myocardial velocities. The TPM sequence may add functional information for monitoring graft dysfunction. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 2 J. Magn. Reson. Imaging 2020;52:920-929.

Efficacy and Safety of Mineralocorticoid Receptor Antagonists in Patients With Heart Failure and Chronic Kidney Disease.

Mineralocorticoid receptor antagonists (MRA) improve clinical outcomes in patients with heart failure with reduced ejection fraction (HFrEF) and reduce risk of heart failure (HF) hospitalization in patients with heart failure with preserved ejection fraction (HFpEF). However, the benefit and risks of MRA use are not clear in HF patients and chronic kidney disease (CKD) with estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2. We conducted a systematic review evaluating the efficacy and safety of MRA in patients with HF and CKD. PubMed, Embase, and Cochrane Central databases were searched for relevant studies on patients with HF and reduced renal function (defined as eGFR <60 mL/min/1.73 m2). Seven studies with 5,522 patients were included. We found 3 studies in patients with HFrEF, 1 study with HFpEF, and 2 in acute HF and 1 with mixed patient population of HF. Post hoc analyses from randomized controlled trials demonstrated reduction of risk in the primary end point (adverse cardiovascular outcomes and/or all-cause mortality and/or HF hospitalization) with MRA use in the CKD subgroup (eGFR 30 to 60 mL/min/1.73 m2) despite a greater risk of hyperkalemia and higher rates of drug discontinuation. In 3 observational studies, propensity score matching was performed to compare patients treated with and without MRA and did not identify benefits, but conclusions from these studies were limited due to residual confounding and concern for bias. In conclusion, benefits of MRA use in HF appear to be consistent in patients with reduced renal function (eGFR 30 to 60 mL/min/1.73 m).