Preoperative Right Heart Dysfunction and Gastrointestinal Bleeding in Patients with Left Ventricular Assist Devices.

Gastrointestinal bleeding (GIB) is a common cause of morbidity among patients supported by left ventricular assist devices (LVADs). The aim of this study was to identify if pre-LVAD right ventricular (RV) dysfunction is associated with risk of GIB after LVAD implantation. Of 398 patients implanted with LVADs between July 2008 and July 2016, 130 (33%) developed GIB at a median of 2.6 months following LVAD implantation. Arteriovenous malformations (AVMs) were found in 42 (34%) GIB patients. Patients with GIB were older and more likely to have hypertension, diabetes, and ischemic cardiomyopathy. On pre-LVAD echocardiography, GIB patients had increased RV diastolic dimension (4.7 ± 0.8 vs. 4.4 ± 0.9 cm, p = 0.02), a higher rate of greater than mild tricuspid valve (TV) regurgitation (73 [60%] vs. 120 [47%], p = 0.006), and underwent TV repair more often (38 [30%] vs. 43 [16%], p = 0.0006) during LVAD implantation. After multivariable adjustment, preoperative greater than mild RV enlargement (hazard ratio [HR] 2.32, 95% CI 1.12-5.03; p = 0.03), TV regurgitation (HR 1.83, CI 1.02-3.44; p = 0.01), and TV repair (HR 3.76, confidence interval [CI] 1.02-4.44; p = 0.01) remained associated with risk of GIB. This finding was driven by the AVM-GIB subgroup. Preoperative RV enlargement and TV regurgitation are associated with post-LVAD AVM-related GIB.

Impact of donor smoking history on post heart transplant outcomes: A propensity-matched analysis of ISHLT registry.

PURPOSE: Smoking is a major public health issue, and its effect on cardiovascular outcomes is well established. This study evaluates the impact of donor smoking on heart transplant (HT) outcomes. METHODS: HT recipients between January 1, 2005, and December 31, 2016, with known donor smoking status were queried from the International Society of Heart and Lung Transplantation (ISHLT) registry. The primary outcome was all-cause mortality, and secondary endpoints were graft failure, acute rejection, and cardiac allograft vasculopathy. We utilized propensity-score matching to identify cohorts of recipients with and without a history of donor smoking. Hazard ratios for post-transplant outcomes for the matched sample were estimated from separate Cox proportional hazard models. RESULTS: Of 26 390 patients in the cohort, 18.9% had history of donor smoking. Donors with history of smoking were older, predominantly male and had higher incidence of diabetes, hypertension, cocaine use, and "high-risk" status. In propensity-matched analysis, recipients with a history of donor smoking had increased risk of death (HR 1.11, 95% CI 1.03-1.20) and higher risk of graft failure (HR 1.11, 95% CI 1.03-1.20). CONCLUSION: Donor smoking was associated with increased mortality and higher incidence of graft failure following HT. Consideration of donor smoking history is warranted while evaluating donor hearts.

Impaired Exercise Tolerance Early After Heart Transplantation Is Associated With Development of Cardiac Allograft Vasculopathy.

BACKGROUND: Exercise performance remains limited in some patients after heart transplantation (HTx). The goal of this study was to assess for association between cardiopulmonary exercise test performance at 1 year after HTx and future development of cardiac allograft vasculopathy (CAV). METHODS: Overall 243 HTx recipients performed cardiopulmonary exercise testing at 1 year after HTx. During the median follow-up period of 31 (interquartile range 19;61) months, 76 (32%) patients were diagnosed with CAV (CAV group). RESULTS: The CAV group patients had lower exercise capacity (5.2 ± 1.9 versus 6.5 ± 2.2 metabolic equivalents; P = 0.001) and duration (9.6 ± 3.5 versus 11.4 ± 4.8 min; P = 0.008), lower peak oxygen consumption (VO2) (18.4 ± 5.4 versus 21.4 ± 6.1 mL/kg/min; P = 0.0005), lower normalized peak VO2 (63% ± 18% versus 71% ± 19%; P = 0.007), and higher minute ventilation (VE)/carbon dioxide production (VCO2) (34 ± 5 versus 32 ± 5, P = 0.04). On Cox proportional hazards regression analysis, normalized peak VO2 ≤60%, and VE/VCO2 ≥34 were associated with a high hazard for CAV (HR = 1.8 [95% CI 1.10-4.53, P = 0.03] and 2.5 [95% CI 1.01-8.81, P = 0.04], respectively). The subgroup of patients with both normalized peak VO2 ≤60% and VE/VCO2 ≥34 was at highest risk for development of CAV (HR = 5.2, 95% CI 2.27-15.17, P = 0.001). CONCLUSIONS: Normalized peak VO2 ≤60% and VE/VCO2 ≥34 at 1 year after HTx are associated with the development of CAV.

Ethnic disparity in Israel impacts long-term results after heart transplantation.

BACKGROUND: Ethnicity may affect graft longevity and recipient mortality after heart transplantation (HTx). We hypothesized that differences in ethnic origin between Arabs and Jews undergoing HTx in Israel may contribute to differences in long-term outcomes. METHODS: The study population comprised all 254 patients who underwent HTx between 1991 and 2017 in a tertiary medical center located in the center of Israel. Patients were categorized as either Jews (226 patients, 89%) or Arabs (28 patients, 11%). The primary end point was cardiac allograft vasculopathy (CAV), secondary end points were cardiovascular (CV) mortality and the combined end point of CAV/CV mortality. RESULTS: In comparison with Jews, Arab patients were significantly younger (ave. age 42 vs. 50) and had shorter in-hospital stay (45 vs. 80 days). However, Kaplan-Meier survival analysis showed that at 10 years of follow-up CAV rates were significantly higher among Arabs (58%) compared with Jews (23%; log-rank P = 0.01) for the overall difference during follow-up. Similar results were shown for the separate end point of CV mortality and the combined end point of CAV/CV mortality. Multivariate analysis, which controlled for age, gender, statin treatment, and other potential confounders, showed that Arab recipient ethnic origin was associated with a significant > 2.5-fold (p = 0.01) increase in the risk for CAV; a > 4-fold increase in the risk for CV mortality (p = 0.001); and approximately 4-fold increase in the risk for the combined end point (p = 0.001). These findings were validated by propensity score analysis. CONCLUSIONS: Our data suggest that Arab ethnic origin is associated with a significantly increased risk for CAV and mortality following HTx. Suggested explanations contributing to ethnic disparities in Israel include socioeconomic, environmental and genetic factors. Further studies are required to evaluate whether more aggressive risk factor management in the Israeli Arab population following HTx would reduce CAV and CV mortality in this high-risk population. Increased awareness and early intervention of the Israeli healthcare system and cooperation with the Arab community is of paramount importance.

Elevated Heart Rate Following Heart Transplantation Is Associated With Increased Graft Vasculopathy and Mortality.

BACKGROUND: The effect of elevated heart rate (HR) on outcomes after heart transplantation (HT) has not been well established. The aim of this study was to assess predictors of elevated HR following HT and its impact on outcomes. METHODS AND RESULTS: We retrospectively evaluated 394 patients who underwent HT at 2 academic medical centers from 2005 to 2016. Patients were divided into 2 groups based on HR 1 year after HT: HR ≥95 beats/min (n = 162; 41%) and HR <95 beats/min (n = 232; 59%). Median follow-up time was 6.6 (interquartile range [IQR] 2.2-7.5) years. HR ≥95 beats/min 1 year after HT was associated with younger donor age, whereas HR <95 beats/min was associated with heavy donor alcohol use and African-American recipient race. Left ventricular (LV) end-diastolic dimension, mass, and ejection fraction were lower and E/E' higher in the HR ≥95 group at the time of the last follow up. HR ≥95 beats/min at 1 year after HT was independently associated with the development of cardiac allograft vasculopathy and increased mortality. CONCLUSIONS: HR ≥95 beats/min 1 year after HT is associated with a reduction in LV size and function, increased incidence of cardiac allograft vasculopathy, and reduced survival. Studies investigating the effect of medical HR reduction on post-HT outcomes are warranted.

Gastrointestinal Bleeding With Left Ventricular Assist Devices (LVAD): Locating the Leak and Identifying Outcomes.

BACKGROUND AND GOALS: Gastrointestinal bleeding (GIB) is a significant complication following left ventricular assist device (LVAD) implantation. We evaluated the incidence, predictors, endoscopic findings, and outcomes of GIB in LVAD recipients. STUDY: Retrospective review of 205 adult patients undergoing HeartMate II LVAD implantation from January 2012 to June 2016. Patients were reviewed and separated into GIB (n=57; 28%) and non-GIB (n=148; 72%) groups. RESULTS: Median time to GIB was 55 (range, 3 to 730) days. The GIB group patients were older (61±12 vs. 56±13, P=0.0042), more often underwent concomitant tricuspid valve (TV) repair (16% vs. 4%, P=0.007), and a higher percentage were assigned for destination therapy (75% vs. 55%, P=0.01). Angioectasia (33%) was the most common identified cause of GIB. Median time to endoscopic intervention was 1 day. The total number of hospital readmissions after LVAD was higher in the GIB group (median of 5 vs. 3, P=0.001), as was the total number of blood products transfused after LVAD (29 vs. 13, P≤0.0001). GIB was associated with an increased risk of death (hazard ratio, 1.94; 95% confidence interval, 1.16-3.25; P=0.01) and the mortality rate during hospitalization for GIB was 11% (P=0.0004). Receiving a heart transplant was associated with a decreased hazard of death (hazard ratio, 0.40; 95% confidence interval, 0.19-0.85; P=0.016). CONCLUSIONS: Older age and destination therapy as implant strategy were found to be associated with an increased risk of GIB, consistent with previous studies. A unique finding in our study is the association of TV repair with a higher incidence of GIB. Further studies are needed to investigate possible mechanisms by which TV repair increases the incidence of GIB.

Left Ventricular Assist Devices in Pulmonary Hypertension Group 2 With Significantly Elevated Pulmonary Vascular Resistance: A Bridge to Cure.

BACKGROUND: Pulmonary hypertension secondary to left heart disease (WHO Group 2) is a known risk factor in patients with heart failure. The favourable effect of left ventricular assist devices (LVAD) on pulmonary hypertension has been demonstrated before, although this effect has not been well-studied in advanced pulmonary arterial bed disease with a significant elevation in pulmonary vascular resistance. METHODS: We reviewed the records of 258 LVAD patients in our institution. Patients with elevated mean pulmonary artery pressure (mPAP>25mmHg) and elevated pulmonary vascular resistance (PVR ≥3 Wood units) were included in the study. Patients were divided into two groups based on their baseline PVR (PVR=3-5 Wood units (WU) vs. PVR>5WU). The groups were studied for the changes in their pulmonary haemodynamics after the placement of LVAD. RESULTS: Fifty-one (51) patients were included in the study. All patients showed a significant improvement in their pulmonary haemodynamic parameters post LVAD placement. In the group with the higher PVR, mPAP dropped from a baseline of 43±7mmHg to 22±6mmHg post LVAD placement (p<0.001), while PVR dropped from 6.3±1.2 Wood units to 2.2±1.1 Wood units (p<0.001). In a subgroup of patients who underwent cardiac transplantation post LVAD (n=14), all patients maintained a normalised PVR (<3WU) one year post cardiac transplantation. CONCLUSIONS: Left ventricular assist devices can reverse pulmonary hypertension WHO Group 2 with significantly elevated PVR; this effect is not dependent on the baseline PVR, and is maintained up to one year post cardiac transplantation.

The effect of donor alcohol abuse on outcomes following heart transplantation.

BACKGROUND: Current guidelines recommend against the use of hearts from donors that abuse alcohol. We explored the effect of donor alcohol abuse (AA) on cardiac allograft function and outcomes in heart transplant (HTx) recipients. METHODS: Overall, 370 HTx recipients were divided into two groups: (a) the alcoholic donor group (AD, n = 58) and (b) the non-alcoholic donor group (NAD, n = 312). RESULTS: Recipients in the AD group had a slower heart rate (86 ± 13 vs 93 ± 13, P = 0.004) and an increased incidence of early atrial fibrillation (AF) (30% vs 11%, P = 0.003). Echocardiographic left ventricular mass was higher among alcoholic donors (171.7 ± 66.7 vs 151.6 ± 54.7, P = 0.02). This difference remained present 1 year following HTx (185 ± 43 vs 166 ± 42, P = 0.007). E/E' was higher in the AD group (9.5 ± 3.9 vs 8.4 ± 2.9, P = 0.04) and a larger number of AD recipients had a ventilatory equivalent for VCO2  > 34 (50% vs 31%, P = 0.04) on cardiopulmonary exercise test. There was no significant difference in rejection, cardiac allograft vasculopathy (CAV), or survival between the groups. CONCLUSIONS: Our data suggest that donor AA does not impact rejection, CAV, or intermediate-term survival, but may cause increased incidence of post-HTx AF and impaired cardiac allograft diastolic function.

Donor-recipient ethnic mismatching impacts short- and long-term results of heart transplantation.

BACKGROUND: The impact of donor-recipient ethnic matching on heart transplantation (HT) has been poorly studied with inconclusive results. We aimed to investigate the impact of ethnic matching on HT outcomes in Israeli multiethnic patients. METHODS: The study comprised 168 patients who underwent HT from 1990-2017. Patients and their donors were ethnically categorized to Jews and Arabs. Primary end points were all-cause in-hospital and late mortality; secondary end points included primary graft dysfunction (PGD), rejections, and vasculopathy. RESULTS: Donor-recipient ethnic matching was found in 111 patients, while 57 were ethnically mismatched. Baseline characteristics were similar in both groups. Ethnic mismatching was associated with >7-fold (P = 0.018) increased risk for in-hospital mortality and >8-fold (P < 0.001) increased risk for PGD. Kaplan-Meier survival analysis showed that overall survival at 10 years was significantly higher among matched patients (73% vs 43%, log-rank P < 0.001). Multivariate analysis showed that ethnic mismatching was associated with an approximately fourfold higher risk for death (P < 0.01). These findings were validated by propensity score analysis. The ethnic mismatched group experienced significantly higher rejection rates compared with the matched group with lower survival free of rejections (log-rank P = 0.029). No differences in vasculopathy were found. CONCLUSIONS: Donor-recipient ethnic mismatch is an important independent predictor of early- and long-term outcomes following HT, and is associated with increased risk for PGD, rejections, and mortality. These findings will help to design tailored treatment protocols leading to improved outcomes after HT.

High tacrolimus trough level variability is associated with rejections after heart transplant.

Tacrolimus, the major immunosuppressant after heart transplant (HTx) therapy, is a narrow therapeutic index drug. Hence, achieving stable therapeutic steady state plasma concentrations is essential to ensure efficacy while avoiding toxicity. Whether high variability in steady state concentrations is associated with poor outcomes is unknown. We investigated the association between tacrolimus trough level variability during the first year post-HTx and outcomes during and beyond the first postoperative year. Overall, 72 patients were analyzed for mortality, of whom 65 and 61 were available for rejection analysis during and beyond the first year post-HTx, respectively. Patients were divided into high (median >28.8%) and low tacrolimus level variability (<28.8%) groups. Mean tacrolimus levels did not differ between the groups (12.7 ± 3.4 ng/mL vs 12.8 ± 2.4 ng/mL, P = .930). Patients in the high variability group exhibited higher long-term rejection rate (median total rejection score: 0.33 vs 0, P = .04) with no difference in rejection scores within the first year post-HTx. Multivariate analysis showed that high tacrolimus trough level variability was associated with >8-fold increased risk for any rejection beyond the first year post-HTx (P = .011). Mortality was associated only with cardiovascular complications (P = .018), with no effect of tacrolimus through level variability.

Do Psychosocial Factors Have Any Impact on Outcomes After Left Ventricular Assist Device Implantation?

Psychosocial factors have been show to impact survival and outcomes in a number of different diseases, including heart failure and patients receiving heart transplantation. With the increasing utilization of these devices, it is important to identify risk factors that could impact post-left ventricular assist device (LVAD) outcomes. This study was a single center, retrospective analysis of 238 patients who underwent implantation of a LVAD between July 27, 2004, and July 21, 2016, at The University of Nebraska Medical Center. Data collected include length of stay, number of readmission, alive status at 30 days, 180 days, and 1 year, as well as multiple psychosocial factors including history of drug abuse, history of alcohol abuse, history of noncompliance, history of anxiety, and history of depression, among others. Outcomes were calculated using univariate and multivariate analyses with SAS Version 9.4. None of the psychosocial factors assessed in this study showed statistical significance in predicting 30 day or 6 month mortality, but patients who smoked at the time of admission for LVAD implantation had higher mortality at 1 year (odds ratio 4.6, 95% confidence interval, 1.226-15.898, p = 0.011.) Patients with a diagnosis of depression had higher numbers of readmissions compared with those without depression (p = 0.048) with the number of readmissions further increased in patients with a diagnosis of both depression and anxiety (p = 0.0074). Psychosocial determinants do not appear to have a significant effect on mortality, but can result in increased risk of readmission if not adequately addressed before implantation and continually monitored postimplantation.

Depression and anxiety in patients undergoing left ventricular assist device implantation.

BACKGROUND: Depression and anxiety are associated with a worse prognosis in heart failure patients. The aim of this study was to identify the prevalence of depression and anxiety in left ventricular assist device (LVAD) candidates and assess their effect on post-LVAD outcomes. METHODS: Based on the pre-LVAD psychological assessment, the total cohort of 246 patients were divided into 4 groups: 1) no depression or anxiety (NDep&Anx group, n = 138); 2) isolated depression (Dep group, n = 42); 3) isolated anxiety (Anx group, n = 32), and 4) combined depression and anxiety (Dep&Anx group, n = 34). RESULTS: The Dep&Anx group was associated with higher prevalence of female gender (p = 0.03), higher body mass index (p = 0.03), elevated E/E' (p = 0.003), and increased Model For End-Stage Liver Disease (MELD) XI score (p = 0.04) prior to LVAD as compared to the other 3 subgroups. The prevalence of other major psychiatric disorders (p = 0.03) and narcotic dependence (p = 0.004) was higher in the Dep&Anx group. Post-LVAD implantation, heart rate and filling pressures were elevated and readmission rate was higher (p = 0.001) in the Dep&Anx group. There was no difference in survival between the groups (p = 0.40, Log-Rank test). CONCLUSIONS: Pre-existing anxiety and depression was associated with worse HF pre- and post-LVAD implantation and higher readmissions rate after LVAD implantation.

Early aspirin initiation following heart transplantation is associated with reduced risk of allograft vasculopathy during long-term follow-up.

AIM: Cardiac allograft vasculopathy (CAV) is a major cause of morbidity and mortality after heart transplantation (HT). Enhanced platelet reactivity is a contributing factor. We aimed to investigate the association between early initiation of aspirin therapy post-HT and the 15-year risk of the development of CAV. METHODS: We studied 206 patients who underwent HT between 1991 and 2016. Multivariate Cox proportional hazards regression modeling was employed to evaluate the association between early aspirin initiation and the long-term risk of CAV. RESULTS: Ninety-seven patients (47%) received aspirin therapy. At 15 years of follow-up, the rate of CAV was lowered by sixfold in patients treated with aspirin compared with the non-treated patients: 7% vs 37% (log-rank P-value<.001). The corresponding rates of the combined end-point of CAV or death were also lower in patients treated with aspirin, compared with the non-treated patients: 42% vs 78% (log-rank P < .001). Consistently, multivariate analysis showed that early aspirin therapy was associated with a significant 84% (P < .001) reduction in CAV risk, and with a corresponding 68% (P < .0001) reduction in the risk of the combined end-point of CAV or death. We further validated these results using a propensity score-adjusted Cox model. CONCLUSIONS: Early aspirin initiation is independently associated with a significant reduction in the risk of CAV.

Metformin therapy reduces the risk of malignancy after heart transplantation.

BACKGROUND: Malignancy and diabetes mellitus (DM) cause significant morbidity and mortality after heart transplantation (HTx). Metformin, one of the most commonly used anti-diabetic drugs worldwide, has also been shown to exhibit anti-tumor activity. We therefore investigated the association between metformin therapy and malignancy after HTx. METHODS: The study population comprised 237 patients who underwent HTx between 1991 and 2016 and were prospectively followed-up. Clinical data were recorded on prospectively designed forms. The primary outcome was any cancer recorded during 15 years of follow-up. Treatment with metformin and the development of DM after HTx were assessed as time-dependent factors in the analyses. RESULTS: Of the 237 study patients, 85 (36%) had diabetes. Of the DM patients, 48 (56%) were treated with metformin. Kaplan-Meier survival analysis showed that, at 15 years after HTx, malignancy rate was 4% for DM patients treated with metformin, 62% for those who did not receive metformin and 27% for non-DM patients (log-rank test, p < 0.0001). Consistently, multivariate analysis showed that for DM patients, metformin therapy was independently associated with a significant 90% reduction (hazard ratio = 0.10; 95% confidence interval 0.02 to 0.40; p = 0.001) in the risk of the development of a malignancy. DM patients who were treated with metformin had a markedly lower risk (65%; p = 0.001) for the development of a malignancy or death after HTx as compared with non-DM patients. CONCLUSIONS: Our findings suggest that metformin therapy is independently associated with a significant reduction in the risk of malignancy after HTx.

Risk of early, intermediate, and late rejection following heart transplantation: Trends over the past 25 years and relation to changes in medical management. Tertiary center experience: The Sheba Heart Transplantation Registry.

AIM: To explore the trends in the risk for rejection following heart transplantation (HT) over the past 25 years, and their relation to changes in medical management. METHODS: The study population comprised 216 HT patients. Rejection periods were defined as follows: 0-3 months (early), 3-12 months (intermediate), and 12+ months (late). HT era was dichotomized as follows: 1991-1999 (remote era) and 2000-2016 (recent era). Medication combination was categorized as newer (TAC, MMF, and everolimus) vs older therapies (AZA, CSA). RESULTS: Multivariate analysis showed that patients who underwent HT during the recent era experienced a significant reduction in the risk for major rejection. These findings were consistent for early (OR = 0.44 [95% CI 0.22-0.88]), intermediate (OR = 0.02 [95% CI 0.003-0.11]), and late rejections (OR = 0.18 [95% CI 0.05-0.52]). Using the year of HT as a continuous measure showed that each 1-year increment was independently associated with a significant reduction in the risk for early, intermediate, and late rejections (5%, 21%, 18%, respectively). In contrast, the risk reduction associated with newer types of immunosuppressive therapies was not statistically significant after adjustment for the treatment period. CONCLUSIONS: Major rejection rates following HT have significantly declined over the past 2 decades even after adjustment for changes in immunosuppressive therapies, suggesting that other factors may also play a role in the improved outcomes of HT recipients.

Effect of diltiazem on exercise capacity after heart transplantation.

BACKGROUND: Sinus tachycardia (ST) is common after heart transplantation (HTx). The aim of the study was to evaluate the effect of diltiazem treatment during the first year after HTx on heart rate (HR), cardiac allograft function, and exercise capacity. METHODS: From the total cohort, 25 HTx recipients started diltiazem treatment 4±2 weeks after HTx and continued it for at least 1 year (diltiazem group). Each study case was matched to a control. All patients underwent hemodynamic assessment and cardiopulmonary exercise test (CPET) at 1 year after HTx. RESULTS: HR decreased in the diltiazem group from 99±11 bpm to 94±7 bpm (P=.03) and did not change in the controls (98±11 bpm vs 100±13 bpm, P=.14). The difference between the groups at 1 year after HTx was significant (P=.04). In the diltiazem group left ventricular (LV), stroke volume and ejection fraction increased (48±16 vs 55±17 mL, P=.02, and 60%±10% vs 62%±12% P=.03, respectively) but did not differ from controls. E/E' decreased (10.7±2.7 vs 7.3±1.9, P=.003) while cardiac index was higher (3.5±0.8 vs 3.1±0.5; P=.05) in the diltiazem group at 1-year follow-up. The absolute peak VO2 (21±4 vs 18±6 mL/kg/min; P=.05) and normalized peak VO2 (73%±17% vs 58%±14%; P=.004) were significantly higher in the diltiazem group. CONCLUSIONS: This study showed that diltiazem treatment reduces ST, may improve cardiac allograft function and exercise tolerance during the first year after HTx.

Sinus tachycardia is associated with impaired exercise tolerance following heart transplantation.

BACKGROUND: Sinus tachycardia often presents in heart transplantation (HTx) recipients, but data on its effect on exercise performance are limited. METHODS: Based on mean heart rate (HR) value 3 months after HTx, 181 patients transplanted from 2006 to 2015 at University of Nebraska Medical Center were divided into two groups: (i) HR<95 beats/min (bpm, n=93); and (ii) HR≥95 bpm (n=88). Cardiopulmonary exercise testing (CPET) was performed 1 year after HTx. RESULTS: Mean HR at 3 months post-HTx was 94±11 bpm and did not change significantly at 1 year post-HTx (96±11 bpm, P=.13). HR≥95 bpm at 3 months was associated with younger donor age (OR 1.1; CI 1.0-1.1, P=.02), female donors (OR -2.4; CI 1.16-5.24 P=.02), and lack of donors' heavy alcohol use (OR -0.43; CI 0.17-0.61; P=.04). HR≥95 bpm at 3 months post-HTx was independently associated with decreased exercise capacity in metabolic equivalent (P=.008), reduced peak VO2 (P=.006), and percent of predicted peak VO2 (P=.002) during CPET. CONCLUSIONS: HR≥95 at 3 months following HTx is associated with reduced exercise tolerance in stable HTx recipients. Medical HR reduction after HTx could improve exercise performance after HTx and merits further investigation.

Targeted myocardial gene expression in failing hearts by RNA sequencing.

BACKGROUND: Myocardial recovery with left ventricular assist device (LVAD) therapy is highly variable and difficult to predict. Next generation ribonucleic acid (RNA) sequencing is an innovative, rapid, and quantitative approach to gene expression profiling in small amounts of tissue. Our primary goal was to identify baseline transcriptional profiles in non-ischemic cardiomyopathies that predict myocardial recovery in response to LVAD therapy. We also sought to verify transcriptional differences between failing and non-failing human hearts. METHODS: RNA was isolated from failing (n = 16) and non-failing (n = 8) human hearts. RNA from each patient was reverse transcribed and quantitatively sequenced on the personal genome machine (PGM) sequencer (Ion torrent) for 95 heart failure candidate genes. Coverage analysis as well as mapping the reads and alignment was done using the Ion Torrent Browser Suite™. Differential expression analyses were conducted by empirical analysis of digital gene expression data in R (edgeR) to identify differential expressed genes between failing and non-failing groups, and between responder and non-responder groups respectively. Targeted cardiac gene messenger RNA (mRNA) expression was analyzed in proportion to the total number of reads. Gene expression profiles from the PGM sequencer were validated by performing RNA sequencing (RNAseq) with the Illumina Hiseq2500 sequencing system. RESULTS: The failing sample population was 75% male with an average age of 50 and a left ventricular ejection fraction (LVEF) of 16%. Myosin light chain kinase (MYLK) and interleukin (IL)-6 genes expression were significantly higher in LVAD responders compared to non-responders. Thirty-six cardiac genes were expressed differentially between failing and non-failing hearts (23 decreased, 13 elevated). MYLK, Beta-1 adrenergic receptor (ADRB1) and myosin heavy chain (MYH)-6 expression were among those significantly decreased in failing hearts compared to non-failing hearts. Natriuretic peptide B (NPPB) and IL-6 were significantly elevated. Targeted gene expression profiles obtained from the Ion torrent PGM sequencer were consistent with those obtained from Illumina HiSeq2500 sequencing system. CONCLUSIONS: Heart failure is associated with a network of transcriptional changes involving contractile proteins, metabolism, adrenergic receptors, protein phosphorylation, and signaling factors. Myocardial MYLK and IL-6 expression are positively correlated with ejection fraction (EF) response to LVAD placement. Targeted RNA sequencing of myocardial gene expression can be utilized to predict responders to LVAD therapy and to better characterize transcriptional changes in human heart failure.

Exercise Training Attenuates Upregulation of p47(phox) and p67(phox) in Hearts of Diabetic Rats.

Exercise training (ExT) is currently being used as a nonpharmacological strategy to improve cardiac function in diabetic patients. However, the molecular mechanism(s) underlying its beneficial effects remains poorly understood. Oxidative stress is known to play a key role in the pathogenesis of diabetic cardiomyopathy and one of the enzyme systems that produce reactive oxygen species is NADH/NADPH oxidase. The goal of this study was to investigate the effect of streptozotocin- (STZ-) induced diabetes on expression of p47(phox) and p67(phox), key regulatory subunits of NADPH oxidase, in cardiac tissues and determine whether ExT can attenuate these changes. Four weeks after STZ treatment, expression of p47(phox) and p67(phox) increased 2.3-fold and 1.6-fold, respectively, in left ventricles of diabetic rats and these increases were attenuated with three weeks of ExT, initiated 1 week after onset of diabetes. In atrial tissues, there was increased expression of p47(phox) (74%), which was decreased by ExT in diabetic rats. Furthermore, increased collagen III levels in diabetic hearts (52%) were significantly reduced by ExT. Taken together, ExT attenuates the increased expression of p47(phox) and p67(phox) in the hearts of diabetic rats which could be an underlying mechanism for improving intracardiac matrix and thus cardiac function and prevent cardiac remodeling in diabetic cardiomyopathy.