Impact of Donor Hemodynamics on Recipient Survival in Heart Transplantation.

BACKGROUND: Heart transplantation is the gold-standard therapy for end-stage heart failure, but rates of donor-heart use remain low due to various factors that are often not evidence based. The impact of donor hemodynamics obtained via right-heart catheterization on recipient survival remains unclear. METHODS: The United Network for Organ Sharing registry was used to identify donors and recipients from September 1999-December 2019. Donor hemodynamics data were obtained and analyzed using univariate and multivariable logistical regression, with the primary endpoints being 1- and 5-year post-transplant survival. RESULTS: Of the 85,333 donors who consented to heart transplantation during the study period, 6573 (7.7%) underwent right-heart catheterization, of whom 5531 eventually underwent procurement and transplantation. Donors were more likely to undergo right-heart catheterization if they had high-risk criteria. Recipients who had donor hemodynamic assessment had 1- and 5-year survival rates similar to those without donor hemodynamic assessment (87% vs 86%, 1 year). Abnormal hemodynamics were common in donor hearts but did not impact recipient survival rates, even when risk-adjusted in multivariable analysis. CONCLUSIONS: Donors with abnormal hemodynamics may represent an opportunity to expand the pool of viable donor hearts.

Beta-Blocker Use and Heart Failure Outcomes in Mildly Reduced and Preserved Ejection Fraction.

BACKGROUND: Although studies consistently show that beta-blockers reduce morbidity and mortality in patients with reduced ejection fraction (EF), data are inconsistent in patients with heart failure with mildly reduced ejection fraction (HFmrEF) and suggest potential negative effects in heart failure with preserved ejection fraction (HFpEF). OBJECTIVES: The purpose of this study was to examine the association of beta-blockers with heart failure (HF) hospitalization and death in patients with HF and EF ≥40% METHODS: Beta-blocker use was assessed at first encounter in outpatients ≥65 years of age with HFmrEF and HFpEF in the U.S. PINNACLE Registry (2013-2017). The associations of beta-blockers with HF hospitalization, death, and the composite of HF hospitalization/death were assessed using propensity-score adjusted multivariable Cox regression models, including interactions of EF × beta-blocker use. RESULTS: Among 435,897 patients with HF and EF ≥40% (HFmrEF, n = 75,674; HFpEF = 360,223), 289,377 (66.4%) were using a beta-blocker at first encounter; more commonly in patients with HFmrEF vs HFpEF (77.7% vs 64.0%; P < 0.001). There were significant interactions between EF × beta-blocker use for HF hospitalization, death, and composite of HF hospitalization/death (P < 0.001 for all), with higher risk with beta-blocker use as EF increased. Beta-blockers were associated with decreased risk of HF hospitalization and death in patients with HFmrEF but a lack of survival benefit and a higher risk of HF hospitalization in patients with HFpEF, particularly when EF was >60%. CONCLUSIONS: In a large, real-world, propensity score-adjusted cohort of older outpatients with HF and EF ≥40%, beta-blocker use was associated with a higher risk of HF hospitalization as EF increased, with potential benefit in patients with HFmrEF and potential risk in patients with higher EF (particularly >60%). Further studies are needed to understand the appropriateness of beta-blocker use in patients with HFpEF in the absence of compelling indications.

Effect of Personalized Accelerated Pacing on Quality of Life, Physical Activity, and Atrial Fibrillation in Patients With Preclinical and Overt Heart Failure With Preserved Ejection Fraction: The myPACE Randomized Clinical Trial.

Importance: Patients with heart failure with preserved ejection fraction (HFpEF) with a pacemaker may benefit from a higher, more physiologic backup heart rate than the nominal 60 beats per minute (bpm) setting. Objective: To assess the effects of a moderately accelerated personalized backup heart rate compared with 60 bpm (usual care) in patients with preexisting pacemaker systems that limit pacemaker-mediated dyssynchrony. Design, Setting, and Participants: This blinded randomized clinical trial enrolled patients with stage B and C HFpEF from the University of Vermont Medical Center pacemaker clinic between June 2019 and November 2020. Analysis was modified intention to treat. Interventions: Participants were randomly assigned to personalized accelerated pacing or usual care and were followed up for 1 year. The personalized accelerated pacing heart rate was calculated using a resting heart rate algorithm based on height and modified by ejection fraction. Main Outcomes and Measures: The primary outcome was the serial change in Minnesota Living with Heart Failure Questionnaire (MLHFQ) score. Secondary end points were changes in N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, pacemaker-detected physical activity, atrial fibrillation from baseline, and adverse clinical events. Results: Overall, 107 participants were randomly assigned to the personalized accelerated pacing (n = 50) or usual care (n = 57) groups. The median (IQR) age was 75 (69-81) years, and 48 (48%) were female. Over 1-year follow-up, the median (IQR) pacemaker-detected heart rate was 75 (75-80) bpm in the personalized accelerated pacing arm and 65 (63-68) bpm in usual care. MLHFQ scores improved in the personalized accelerated pacing group (median [IQR] baseline MLHFQ score, 26 [8-45]; at 1 month, 15 [2-25]; at 1 year, 9 [4-21]; P < .001) and worsened with usual care (median [IQR] baseline MLHFQ score, 19 [6-42]; at 1 month, 23 [5-39]; at 1 year, 27 [7-52]; P = .03). In addition, personalized accelerated pacing led to improved changes in NT-proBNP levels (mean [SD] decrease of 109 [498] pg/dL vs increase of 128 [537] pg/dL with usual care; P = .02), activity levels (mean [SD], +47 [67] minutes per day vs -22 [35] minutes per day with usual care; P < .001), and device-detected atrial fibrillation (27% relative risk reduction compared with usual care; P = .04) over 1-year of follow-up. Adverse clinical events occurred in 4 patients in the personalized accelerated pacing group and 11 patients in usual care. Conclusions and Relevance: In this study, among patients with HFpEF and pacemakers, treatment with a moderately accelerated, personalized pacing rate was safe and improved quality of life, NT-proBNP levels, physical activity, and atrial fibrillation compared with the usual 60 bpm setting. Trial Registration: ClinicalTrials.gov Identifier: NCT04721314.

Outcomes in Patients With LVADs Undergoing Simultaneous Heart-Kidney Transplantation.

BACKGROUND: Multiple studies have shown better outcomes for simultaneous heart-kidney transplant (sHKT) than for isolated orthotopic heart transplant (iOHT) in recipients with chronic kidney disease (CKD). However, outcomes in patients supported by durable left ventricular assist devices (LVADs) have not been well studied. METHODS: Patients with durable LVADs and stage 3 or higher CKD (eGFR < 60 mL/min/1.73 m2) undergoing iOHT or sHKT between 2008 and 2020 were identified from the United Network for Organ Sharing registry. A Kaplan-Meier survival analysis with associated log-rank test was conducted to compare post-transplant survival rates. Multivariable modeling was used to identify risk-adjusted predictors of 1 year post-transplant mortality. RESULTS: We identified 4375 patients; 366 underwent sHKT, and 4009 underwent iOHT. The frequency of sHKT increased during the study period. The 1-year post-transplant survival rate was worse in patients after sHKT than in patients after iOHT (80.3% vs 88.3%; P < 0.001) and persisted up to 5 years post-transplant (P = 0.001). sHKT recipients were more likely to require dialysis after transplantation and had longer hospital lengths of stay (P < 0.001). Multivariable analysis showed that sHKT remained an independent risk factor for mortality at 1 year (OR 1.58; P = 0.002). CONCLUSIONS: sHKT is becoming more common in patients with durable LVADs. Compared with iOHT, patients with sHKTs have worse short- and long-term survival rates and are more likely to require post-transplant dialysis.

Personalized pacing for diastolic dysfunction and heart failure with preserved ejection fraction: Design and rationale for the myPACE randomized controlled trial.

BACKGROUND: Patients with pacemakers and heart failure with preserved ejection fraction (HFpEF) or isolated diastolic dysfunction (DD) may benefit from a higher backup heart rate (HR) setting compared with the standard setting of 60 bpm. OBJECTIVE: The purpose of this study was to assess the effects of a personalized backup HR setting (myPACE group) compared with 60 bpm (control group). METHODS: In this prospective, blinded, randomized controlled study, pacemaker patients with DD or HFpEF and atrial pacing with intrinsic ventricular conduction or conduction system or biventricular pacing are randomized to the myPACE group or control group for 1 year. The primary outcome is the change in Minnesota Living with Heart Failure Questionnaire (MLHFQ) scores. Secondary endpoints include changes in N-terminal pro-brain natriuretic peptide levels, physical and emotional MLHFQ subscores, and pacemaker-detected atrial arrhythmia burden, patient activity levels, and thoracic impedance; hospitalization for heart failure, atrial fibrillation, cerebrovascular accident, or myocardial infarction; and loop diuretic or antiarrhythmic medication initiation or up-titration. A sample size of 118 subjects is expected to allow detection of a 5-point change in MLHFQ score in an intention-to-treat analysis and allow initial assessment of clinical outcomes and subgroup analyses. RESULTS: Enrollment began in July 2019. As of November 2020, 107 subjects have been enrolled. It is projected that the 1-year follow-up will be completed by December 2021. CONCLUSION: Atrial pacing with intrinsic ventricular conduction or advanced ventricular pacing at a higher, personalized backup HR may be a therapeutic target for patients with isolated DD or HFpEF. The myPACE trial is designed to test this hypothesis.

Beta-Blocker Use in Hypertension and Heart Failure (A Secondary Analysis of the Systolic Blood Pressure Intervention Trial).

Given the concern that beta-blocker use may be associated with an increased risk for heart failure (HF) in populations with normal left ventricular systolic function, we evaluated the association between beta-blocker use and incident HF events, as well as loop diuretic initiation in the Systolic Blood Pressure Intervention Trial (SPRINT). SPRINT demonstrated that a blood pressure target of <120 mm Hg reduced cardiovascular outcomes compared with <140 mm Hg in adults with at least one cardiovascular risk factor and without HF. The lower rate of the composite primary outcome in the 120 mm Hg group was primarily driven by a reduction in HF events. Subjects on a beta blocker for the entire trial duration were compared with subjects who never received a beta blocker after 1:1 propensity score matching. A competing risk survival analysis by beta-blocker status was performed to estimate the effect of the drug on incident HF and was then repeated for a secondary end point of cardiovascular disease death. Among the 3,284 propensity score-matched subjects, beta-blocker exposure was associated with an increased HF risk (hazard ratio 5.86; 95% confidence interval 2.73 to 13.04; p <0.001). A sensitivity analysis of propensity score-matched cohorts with a history of coronary artery disease or atrial fibrillation revealed the same association (hazard ratio 3.49; 95% confidence interval 1.15 to 10.06; p = 0.028). In conclusion, beta-blocker exposure in this secondary analysis was associated with increased incident HF in subjects with hypertension without HF at baseline.

Heart Rate-Induced Myocardial Ca2+ Retention and Left Ventricular Volume Loss in Patients With Heart Failure With Preserved Ejection Fraction.

Background Increases in heart rate are thought to result in incomplete left ventricular (LV) relaxation and elevated filling pressures in patients with heart failure with preserved ejection fraction (HFpEF). Experimental studies in isolated human myocardium have suggested that incomplete relaxation is a result of cellular Ca2+ overload caused by increased myocardial Na+ levels. We tested these heart rate paradigms in patients with HFpEF and referent controls without hypertension. Methods and Results In 22 fully sedated and instrumented patients (12 controls and 10 patients with HFpEF) in sinus rhythm with a preserved ejection fraction (≥50%) we assessed left-sided filling pressures and volumes in sinus rhythm and with atrial pacing (95 beats per minute and 125 beats per minute) before atrial fibrillation ablation. Coronary sinus blood samples and flow measurements were also obtained. Seven women and 15 men were studied (aged 59±10 years, ejection fraction 61%±4%). Patients with HFpEF had a history of hypertension, dyspnea on exertion, concentric LV remodeling and a dilated left atrium, whereas controls did not. Pacing at 125 beats per minute lowered the mean LV end-diastolic pressure in both groups (controls -4.3±4.1 mm Hg versus patients with HFpEF -8.5±6.0 mm Hg, P=0.08). Pacing also reduced LV end-diastolic volumes. The volume loss was about twice as much in the HFpEF group (controls -15%±14% versus patients with HFpEF -32%±11%, P=0.009). Coronary venous [Ca2+] increased after pacing at 125 beats per minute in patients with HFpEF but not in controls. [Na+] did not change. Conclusions Higher resting heart rates are associated with lower filling pressures in patients with and without HFpEF. Incomplete relaxation and LV filling at high heart rates lead to a reduction in LV volumes that is more pronounced in patients with HFpEF and may be associated with myocardial Ca2+ retention.

Association of ß-Blocker Use With Heart Failure Hospitalizations and Cardiovascular Disease Mortality Among Patients With Heart Failure With a Preserved Ejection Fraction: A Secondary Analysis of the TOPCAT Trial.

Importance: ß-Blockers are prescribed to most patients with heart failure (HF) with a preserved ejection fraction (HFpEF), but their effect on HFpEF remains unclear. Objective: To determine the association of ß-blocker use with HF hospitalizations and cardiovascular disease (CVD) mortality, overall and in strata of patients with an ejection fraction (EF) of 50% or greater or less than 50%. Design, Setting, and Participants: For 1761 participants from North and South America enrolled in the multicenter, double-blinded Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist randomized clinical trial of spironolactone for patients with HFpEF between August 10, 2006, and January 31, 2012, the association of baseline ß-blocker use with HF hospitalization and CVD mortality was analyzed using unadjusted and adjusted Cox proportional hazards regression models, overall and in strata of patients with an EF of 50% or greater or less than 50%. Participants had symptomatic HF with a left ventricular EF of 45% or greater, with enrollment based on either hospitalization attributed to decompensated HF in the prior year or elevated natriuretic peptide levels. Statistical analysis was performed from January 31 to May 2, 2019. Exposure: Use of ß-blockers. Main Outcomes and Measures: Incident HF hospitalization and CVD mortality. Results: Among 1761 participants included in the analysis (879 women and 882 men; mean [SD] age, 71.5 [9.6] years), 1394 (79.2%) reported ß-blocker use and 1567 (89.0%) had an EF of 50% or greater. Hospitalizations for HF occurred for 399 participants (22.7%), and CVD mortality occurred for 229 participants (13.0%). Use of ß-blockers was associated with a higher risk of HF hospitalization among patients with HFpEF with an EF of 50% or greater (hazard ratio, 1.74 [95% CI, 1.28-2.37]; P < .001) but not among patients with an EF between 45% and 49% (hazard ratio, 0.68 [95% CI, 0.28-1.63]; P = .39). There was a significant interaction between ß-blocker use and EF threshold for incident HF hospitalizations (P = .03). Use of ß-blockers was not associated with a change in CVD mortality. Conclusions and Relevance: For patients with an EF of 50% or greater, ß-blocker use was associated with an increased risk of HF hospitalizations but not CVD mortality. For patients with an EF between 45% and 49%, there was no such association.

Treatment of Heart Failure With Preserved Ejection Fraction (HFpEF): the Phenotype-Guided Approach.

The syndrome of heart failure with preserved ejection (HFpEF) continues to rise in prevalence without persuasive evidence of current pharmacologic interventions that can reduce mortality. Clinical trials thus far have generally enrolled "all-comers" with the clinical syndrome of heart failure and objective evidence of a preserved ejection fraction. However, HFpEF is increasingly understood to be a heterogeneous syndrome likely borne from the interplay of genetic predisposition, lifestyle factors, and high burden of associated comorbidities with each contributing to a variety of incompletely understood pathophysiologic abnormalities. Complicating management further, such abnormalities appear to be present to varying degrees among individual patients. Ongoing studies, along with the use of computational statistics/machine learning, offer the hope of clarifying the pathophysiological substrates giving rise to the syndrome of HFpEF in different patient subsets. With better understanding of the syndrome's underpinnings, there will be the potential for development of truly targeted therapies. However, for now, there is substantial evidence for the use of currently available pharmacologic device and lifestyle therapy for the optimized management of patients. Such therapy can be tailored to presently identifiable patient clusters-called "phenotypes"-distinguished by both the presence of predominant presenting symptoms and/or predominant comorbidity profiles. Examples of clinical presentation phenotypes include lung congestion, chronotropic incompetence, pulmonary hypertension, or skeletal muscle weakness as predominant features. Additionally, such patients may have underlying metabolic syndrome, systemic (arterial) hypertension, renal dysfunction, atrial fibrillation, and/or coronary artery disease as principal underlying comorbidities. Here, we review a "phenotype-guided" approach to the management of patients with HFpEF, based on a stepwise method of making the HFpEF diagnosis, identifying the prominent sources of organ dysfunction, and treating accordingly.

Left Atrial Appendage Closure: A Safe and Effective Alternative to Anticoagulation?

To date, left atrial appendage closure (LAAC) devices continue to be assessed as an intuitive alternative to oral anticoagulant therapy to prevent embolic complications in patients with atrial fibrillation. Concerns remain about the up-front risks associated with device implantation as well as device efficacy in preventing embolic events as compared with anticoagulation. Currently, LAAC devices serve as a potential alternative to long-term anticoagulation with the benefit of decreased bleeding risk but with less protection against ischemic events. An individualized risk-benefit analysis with regard to stroke possibility, bleeding likelihood with long-term anticoagulation, the risks of an invasive procedure, and the risks associated with having a lifelong intracardiac device should be performed to guide careful patient selection for this operation.