Serial direct sodium removal in patients with heart failure and diuretic resistance

AIMS

Loop diuretics may exacerbate cardiorenal syndrome (CRS) in heart failure (HF). Direct sodium removal (DSR) using the peritoneal membrane, in conjunction with complete diuretic withdrawal, may improve CRS and diuretic resistance.

METHODS AND RESULTS

Patients with HF requiring high-dose loop diuretics were enrolled in two prospective, single-arm studies: RED DESERT (n = 8 euvolaemic patients), and SAHARA (n = 10 hypervolaemic patients). Loop diuretics were withdrawn, and serial DSR was utilized to achieve and maintain euvolaemia. At baseline, participants required a median 240 mg (interquartile range [IQR] 200-400) oral furosemide equivalents/day, which was withdrawn in all participants during DSR (median time of DSR 4 weeks [IQR 4-6]). Diuretic response (queried by formal 40 mg intravenous furosemide challenge and 6 h urine sodium quantification) increased substantially from baseline (81 ± 37 mmol) to end of DSR (223 ± 71 mmol, p < 0.001). Median time to re-initiate diuretics was 87 days, and the median re-initiation dose was 8% (IQR 6-10%) of baseline. At 1 year, diuretic dose remained substantially below baseline (30 [IQR 7.5-40] mg furosemide equivalents/day). Multiple dimensions of kidney function such as filtration, uraemic toxin excretion, kidney injury, and electrolyte handling improved (p < 0.05 for all). HF-related biomarkers including N-terminal pro-B-type natriuretic peptide, carbohydrate antigen-125, soluble ST2, interleukin-6, and growth differentiation factor-15 (p < 0.003 for all) also improved.

CONCLUSIONS

In patients with HF and diuretic resistance, serial DSR therapy with loop diuretic withdrawal was feasible and associated with substantial and persistent improvement in diuretic resistance and several cardiorenal parameters. If replicated in randomized controlled studies, DSR may represent a novel therapy for diuretic resistance and CRS.

CLINICAL TRIAL REGISTRATION

RED DESERT (NCT04116034), SAHARA (NCT04882358).

Influence of left ventricular ejection fraction in patients undergoing contemporary pLVAD-supported high-risk PCI

BACKGROUND

Left ventricular (LV) systolic dysfunction worsens outcomes in patients undergoing percutaneous coronary intervention (PCI). The objective of this study, therefore, was to evaluate outcomes of pLVAD-supported high-risk PCI (HRPCI) patients according to LV ejection fraction (LVEF).

METHODS

Patients from the PROTECT III study undergoing pLVAD-supported HRPCI were stratified according to baseline LVEF: severe LV dysfunction (LVEF <30%), mild and moderate LV dysfunction (LVEF ≥30% to <50%), or preserved LV function (LVEF ≥50%). Major adverse cardiovascular and cerebrovascular events (MACCE: composite of all-cause death, myocardial infarction, stroke/transient ischemic attack, and repeat revascularization), and PCI-related complications were assessed at 90 days and mortality was assessed at 1-year.

RESULTS

From March 2017 to March 2020, 940 patients had evaluable baseline LVEF recorded in the study database. Patients with preserved LV function were older, more frequently presented with myocardial infarction, and underwent more left main PCI and atherectomy. Immediate PCI-related coronary complications were infrequent (2.7%, overall), similar between groups (P = 0.98), and not associated with LVEF. Unadjusted 90-day MACCE rates were similar among LVEF groups; however, as a continuous variable, LVEF was associated with both 90-day MACCE (adj.HR per 5% 0.89, 95% CI [0.80, 0.98], P = 0.018) and 1-year mortality (adj.HR per 5% 0.84 [0.78, 0.90], P <0.0001).

CONCLUSIONS

Patients who underwent pLVAD-supported HRPCI exhibited low incidence of PCI-related complications, regardless of baseline LVEF. However, LVEF was associated with 90-day MACCE and 1-year mortality.

Empagliflozin in Heart Failure: Regional Nephron Sodium Handling Effects

SIGNIFICANCE STATEMENT

The effect of sodium-glucose cotransporter-2 inhibitors (SGLT2i) on regional tubular sodium handling is poorly understood in humans. In this study, empagliflozin substantially decreased lithium reabsorption in the proximal tubule (PT) (a marker of proximal tubular sodium reabsorption), a magnitude out of proportion to that expected with only inhibition of sodium-glucose cotransporter-2. This finding was not driven by an "osmotic diuretic" effect; however, several parameters changed in a manner consistent with inhibition of the sodium-hydrogen exchanger 3. The large changes in proximal tubular handling were acutely buffered by increased reabsorption in both the loop of Henle and the distal nephron, resulting in the observed modest acute natriuresis with these agents. After 14 days of empagliflozin, natriuresis waned due to increased reabsorption in the PT and/or loop of Henle. These findings confirm in humans that SGLT2i have complex and important effects on renal tubular solute handling.

BACKGROUND

The effect of SGLT2i on regional tubular sodium handling is poorly understood in humans but may be important for the cardiorenal benefits.

METHODS

This study used a previously reported randomized, placebo-controlled crossover study of empagliflozin 10 mg daily in patients with diabetes and heart failure. Sodium handling in the PT, loop of Henle (loop), and distal nephron was assessed at baseline and day 14 using fractional excretion of lithium (FELi), capturing PT/loop sodium reabsorption. Assessments were made with and without antagonism of sodium reabsorption through the loop using bumetanide.

RESULTS

Empagliflozin resulted in a large decrease in sodium reabsorption in the PT (increase in FELi=7.5%±10.6%, P = 0.001), with several observations suggesting inhibition of PT sodium hydrogen exchanger 3. In the absence of renal compensation, this would be expected to result in approximately 40 g of sodium excretion/24 hours with normal kidney function. However, rapid tubular compensation occurred with increased sodium reabsorption both in the loop ( P < 0.001) and distal nephron ( P < 0.001). Inhibition of sodium-glucose cotransporter-2 did not attenuate over 14 days of empagliflozin ( P = 0.14). However, there were significant reductions in FELi ( P = 0.009), fractional excretion of sodium ( P = 0.004), and absolute fractional distal sodium reabsorption ( P = 0.036), indicating that chronic adaptation to SGLT2i results primarily from increased reabsorption in the loop and/or PT.

CONCLUSIONS

Empagliflozin caused substantial redistribution of intrarenal sodium delivery and reabsorption, providing mechanistic substrate to explain some of the benefits of this class. Importantly, the large increase in sodium exit from the PT was balanced by distal compensation, consistent with SGLT2i excellent safety profile.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

ClinicalTrials.gov ( NCT03027960 ).

Role of ascorbic acid in cardiac allograft vasculopathy

PURPOSE OF THE REVIEW

Cardiac allograft vasculopathy (CAV) is a progressive fibroproliferative disease which occurs after heart transplantation and is associated with significant long-term morbidity and mortality. Currently available strategies including statins, mammalian target of rapamycin (mTOR) inhibitors, and revascularization, have limited overall effectiveness in treating this pathology once the disease process is established. mTOR inhibitors, while effective when used early in the disease process, are not well tolerated, and hence not routinely used in post-transplant care.

RECENT DATA

Recent work on rodent models have given us a novel mechanistic understanding of effects of ascorbic acid in preventing CAV. TET methyl cytosine dioxygenase2 (TET2) reduces vascular smooth muscle cell (VSMC) apoptosis and intimal thickening. TET2 is repressed by interferon γ (IFNγ) in the setting of CAV. Ascorbic acid has been shown to promote TET2 activity and attenuate allograft vasculopathy in animal models and CAV progression in a small clinical trial.

SUMMARY

CAV remains a challenging disease process and needs better preventative strategies. Ascorbic acid improves endothelial dysfunction, reduces reactive oxygen species, and prevents development of intimal hyperplasia by preventing smooth muscle cell apoptosis and hyperproliferation. Further large-scale randomized control studies of ascorbic acid are needed to establish the role in routine post-transplant management.

Dual organ transplantation: when heart alone is not enough

PURPOSE OF REVIEW

The number of dual organ transplantations (DOT) are steadily increasing over the past few years. This is both a reflection of increasing complexity and advanced disease process in the patients and greater transplant center experience with performing dual organ transplants. Due to lack of standardization of the process, there remains significant center-based variability in patient selection, perioperative and long-term management of these patients.

RECENT FINDINGS

Overall posttransplant outcomes for DOT have been acceptable with some immunological advantages because of partial tolerance offered by the second organ. These achievements should, however, be balanced with the ethical implications of bypassing the patients who are listed for single organ transplantation because of the preferential allocation of organs for DOT.

SUMMARY

The field of DOT is expanding rapidly, with good long-term outcomes. There is an urgent need for guidelines to standardize the process of patient selection and listing dual organ transplantation.

The importance of forward flow and venous congestion in diuretic response in acute heart failure: Insights from the ESCAPE trial

AIMS

Previous studies have suggested venous congestion as a stronger mediator of negative cardio-renal interactions than low cardiac output, with neither factor having a dominant role. While the influence of these parameters on glomerular filtration have been described, the impact on diuretic responsiveness is unclear. The goal of this analysis was to understand the hemodynamic correlates of diuretic response in hospitalized patients with heart failure.

METHODS AND RESULTS

We analyzed patients from the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) dataset. Diuretic efficiency (DE) was defined as the average daily net fluid output per doubling of the peak loop diuretic dose. We evaluated a pulmonary artery catheter hemodynamic-guided cohort (n = 190) and a transthoracic echocardiogram (TTE) cohort (n = 324) where DE was evaluated with hemodynamic and TTE parameters. Metrics of "forward flow" such as cardiac index, mean arterial pressure and left ventricular ejection fraction were not associated with DE (p > 0.2 for all). Worse baseline venous congestion was paradoxically associated with better DE as assessed by right atrial pressure (RAP), right atrial area (RAA), and right ventricular systolic and diastolic area (p < 0.05 for all). Renal perfusion pressure (capturing both congestion and forward flow) was not associated with diuretic response (p = 0.84).

CONCLUSIONS

Worse venous congestion was weakly associated with better loop diuretic response. Metrics of "forward flow" did not demonstrate any correlation with diuretic response. These observations raise questions about the concept of central hemodynamic perturbations as the primary drivers of diuretic resistance on a population level in HF.

In-Hospital Observation on Oral Diuretics After Treatment for Acute Decompensated Heart Failure: Evaluating the Utility

BACKGROUND

Following treatment for acute decompensated heart failure, in-hospital observation on oral diuretics (OOD) is recommended, assuming it provides actionable information on discharge diuretic dosing and thus reduces readmissions.

METHODS

In the Mechanisms of Diuretic Resistance (MDR) cohort, we analyzed in-hospital measures of diuretic response, provider's decisions, and diuretic response ≈30 days postdischarge. In a Yale multicenter cohort, we assessed if in-hospital OOD was associated with 30-day readmission risk. The main objective of this study was to evaluate the utility of in-hospital OOD.

RESULTS

Of the 468 patients in the MDR cohort, 57% (N=265) underwent in-hospital OOD. During the OOD, weight change and net fluid balance correlated poorly with each other (r=0.36). Discharge diuretic dosing was similar between patients who had increased, stable, or decreased weight (decreased discharge dose from OOD dose in 77% versus 72% versus 70%, respectively), net fluid status (decreased discharge dose from OOD dose in 100% versus 69% versus 74%, respectively), and urine output (decreased discharge dose from OOD dose in 69% versus 79% versus 72%, respectively) during the 24-hour OOD period (P>0.27 for all). In participants returning at 30 days for formal quantification of outpatient diuretic response (n=98), outpatient and inpatient OOD natriuresis was poorly correlated (r=0.26). In the Yale multicenter cohort (n=18 454 hospitalizations), OOD occurred in 55% and was not associated with 30-day hospital readmission (hazard ratio, 0.98 [95% CI, 0.93-1.05]; P=0.51).

CONCLUSIONS

In-hospital OOD did not provide actionable information on diuretic response, was not associated with outpatient dose selection, did not predict subsequent outpatient diuretic response, and was not associated with lower readmission rate. Additional research is needed to replicate these findings and understand if these resources could be better allocated elsewhere.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02546583.

Improvement in Renal Function During the Treatment of Acute Decompensated Heart Failure: Relationship With Markers of Renal Tubular Injury and Prognostic Importance

BACKGROUND

Improvement in renal function (IRF) in acute decompensated heart failure is associated with adverse outcomes. The mechanisms driving this paradox remain undefined.

METHODS

Using the ROSE-AHF study (Renal Optimization Strategies Evaluation-Acute Heart Failure), 277 patients were grouped according to renal function, with IRF defined by a ≥20% increase (N=75), worsening renal function by a ≥20% decline (N=53), and stable renal function (SRF) by a <20% change (N=149) in estimated glomerular filtration rate between baseline and 72 hours. Three well-validated renal tubular injury markers, NGAL (neutrophil gelatinase-associated lipocalin), NAG (N-acetyl-β-d-glucosaminidase), and KIM-1 (kidney injury molecule 1), were evaluated at baseline and 72 hours. Patients were also classified by the pattern of change in these markers.

RESULTS

Patients with IRF had the lowest admission estimated glomerular filtration rate (IRF, 37 [28 to 51] mL/min per 1.73 m2; worsening renal function, 43 [35 to 55] mL/min per 1.73 m2; and SRF, 43 [32 to 55] mL/min per 1.73 m2; Ptrend=0.032) but greater cumulative urine output (IRF, 8780 [7025 to 11 208] mL; worsening renal function, 7860 [5555 to 9765] mL; and SRF, 8150 [6325 to 10 456] mL; Ptrend=0.024) and weight loss (IRF, -9.0 [-12.4 to -5.3] lb; worsening renal function, -5.1 [-8.1 to -1.3] lb; and SRF, -7.1 [-11.9 to -3.2] lb; Ptrend<0.001) despite similar diuretic doses (Ptrend=0.16). There were no differences in the relative change in NGAL, NAG, or KIM-1 between renal function groups (Ptrend>0.19 for all). Patients with IRF had worse survival than patients with SRF (27% versus 54%; hazard ratio, 1.98 [1.10-3.58]; P=0.024).

CONCLUSIONS

IRF during decongestive therapy for acute decompensated heart failure was not associated with improved markers of renal tubular injury and was associated with worsened survival, likely driven by the presence of greater underlying cardiorenal dysfunction and more severe congestion.

Left Ventricular Remodeling After Anterior-STEMI PCI: Imaging Observations in the Door-to-Unload (DTU) Pilot Trial

OBJECTIVES

To determine the predictive value of cardiac magnetic resonance (CMR) and echocardiographic parameters on left ventricular (LV) remodeling in ST-segment elevation myocardial infarction (STEMI) patients without cardiogenic shock and treated with mechanical LV unloading followed by immediate or delayed percutaneous coronary intervention (PCI)-mediated reperfusion.

BACKGROUND

In STEMI, infarct size (IS) directly correlates with major cardiovascular outcomes. Preclinical models demonstrate mechanical LV unloading before reperfusion reduces IS. The door-to-unload (DTU)-STEMI pilot trial evaluated the safety and feasibility of LV unloading and delayed reperfusion in patients with STEMI.

METHODS

This multicenter, prospective, randomized, safety and feasibility trial evaluated patients with anterior STEMI randomized 1:1 to LV unloading with the Impella CP (Abiomed) followed by immediate reperfusion vs delayed reperfusion after 30 minutes of unloading. Patients were assessed by CMR at 3-5 days and 30 days post PCI. Echocardiographic evaluations were performed at 3-5 and 90 days post PCI. At 3-5 days post PCI, patients were compared based on IS as percentage of LV mass (group 1 ≤25%, group 2 >25%). Selection of IS threshold was performed post hoc.

RESULTS

Fifty patients were enrolled from April 2017 to May 2018. At 90 days, group 1 (IS ≤25%) exhibited improved LV ejection fraction (from 53.1% to 58.9%; P=.001) and group 2 (IS >25%) demonstrated no improvement (from 37.6% to 39.1%; P=.55). LV end-diastolic volume and end-systolic volume were unchanged in group 1 and worsened in group 2. There was correlation between 3-5 day and 30-day CMR measurements of IS and 90-day echocardiography-derived LV ejection fraction.

CONCLUSIONS

Immediate 3-5 day post-therapy IS by CMR correlates with 90-day echocardiographic LVEF and indices of remodeling. Patients with post-therapy IS >25% demonstrated evidence of adverse remodeling. Larger studies are needed to corroborate these findings with implications on patient management and prognosis.

Risk and predictors of mortality after implantable cardioverter-defibrillator implantation in patients with sarcoid cardiomyopathy

BACKGROUND

Implantable cardioverter-defibrillators (ICDs) are recommended for patients with cardiac sarcoidosis (CS) with an indication for pacing, prior ventricular arrhythmias, cardiac arrest, or left ventricular ejection fraction <35%, but data on outcomes are limited.

METHODS

Using data from the National Cardiovascular Data Registry ICD Registry between April 1, 2010 and December 31, 2015, we evaluated a propensity matched cohort of CS patients implanted with ICDs versus non-ischemic cardiomyopathies (NICM). We compared mortality using Kaplan-Meier survival curves and Cox proportional hazards models.

RESULTS

We identified 1,638 patients with CS and 8,190 propensity matched patients with NICM. The rate of death at 1 and 2 years was similar in patients with CS and patients with NICM (5.2% vs 5.4%, P = 0.75 and 9.0% vs 9.3%, P = 0.72, respectively). After adjusting for other covariates, patients with CS had similar mortality at 2 years after ICD implantations compared with NICM patients (RR 1.03, 95% CI 0.87-1.23). Among patients with CS, multivariable logistic regression identified 6 factors significantly associated with increased 2-year mortality: presence of heart failure (HR 1.92, 95% CI 1.44-3.22), New York Heart Association (NYHA) Class III heart failure (HR 1.68, 95% CI 1.16-2.45), NYHA Class IV heart failure (HR 3.08, 95% CI 1.49-6.39), atrial fibrillation/flutter (HR 1.66, 95% CI 1.17-2.35), chronic lung disease (HR 1.64, 95% CI 1.17-2.29), creatinine >2.0 mg/dL (HR 4.07, 95% CI 2.63-6.30), and paced rhythm (HR 2.66, 95% CI 1.07-6.59).

CONCLUSION

Mortality following ICD implantation was similar in CS patients compared with propensity matched NICM patients. Presence of heart failure, NYHA class, atrial fibrillation/flutter, chronic lung disease, renal dysfunction, and paced rhythm at time of implantation were all predictors of increased 2-year mortality among CS patients with ICDs.

Inferior Vena Cava Diameter Measurement Provides Distinct and Complimentary Information to Right Atrial Pressure in Acute Decompensated Heart Failure

BACKGROUND

Inferior vena cava (IVC) measurements only correlate modestly with right atrial pressure (RAP). Part of this inaccuracy is due to the high compliance of the venous system where a large change in blood volume may result in only a small change in pressure. As such, the information provided by the IVC may be different rather than redundant.

METHODS AND RESULTS

We analyzed patients in the ESCAPE trial who had both pulmonary artery catheter and IVC measurements at baseline (n =108). There was only a modest correlation between baseline RAP and IVC diameter (r =0.41, p<0.001). Hemoconcentration, defined as an increase in hemoglobin from admission to discharge, was correlated with decrease in IVC diameter (r =0.35, p =0.02), but not with a decrease in RAP (r =0.01, p =0.95). When patients had both IVC and RAP measurements below the median, survival was superior to those who had only one below the median, and both above the median fared the worst (p=0.002).

CONCLUSION

IVC and RAP have limited correlation with one another, and changes in intravascular volume appear to correlate better with IVC diameter rather than RAP. Furthermore, there is complimentary information provided by pressure and volume assessments in ADHF.

First Transfemoral Implantation of a Novel Transcatheter Valve in an LVAD Patient With Aortic Insufficiency

An 80-year-old man with a destination left ventricular assist device (LVAD) presented with decompensated heart failure. Evaluation demonstrated numerous LVAD high power spike events, significant aortic regurgitation, and hemolysis. He underwent successful aortic valve replacement with a novel transcatheter valve and LVAD pump exchange that resulted in an improvement in his clinical status. (Level of Difficulty: Advanced.).

Compensatory post-diuretic renal sodium reabsorption is not a dominant mechanism of diuretic resistance in acute heart failure

AIMS

In healthy volunteers, the kidney deploys compensatory post-diuretic sodium reabsorption (CPDSR) following loop diuretic-induced natriuresis, minimizing sodium excretion and producing a neutral sodium balance. CPDSR is extrapolated to non-euvolemic populations as a diuretic resistance mechanism; however, its importance in acute decompensated heart failure (ADHF) is unknown.

METHODS AND RESULTS

Patients with ADHF in the Mechanisms of Diuretic Resistance cohort receiving intravenous loop diuretics (462 administrations in 285 patients) underwent supervised urine collections entailing an immediate pre-diuretic spot urine sample, then 6-h (diuretic-induced natriuresis period) and 18-h (post-diuretic period) urine collections. The average spot urine sodium concentration immediately prior to diuretic administration [median 15 h (13-17) after last diuretic] was 64 ± 33 mmol/L with only 4% of patients having low (<20 mmol/L) urine sodium consistent with CPDSR. Paradoxically, greater 6-h diuretic-induced natriuresis was associated with larger 18-h post-diuretic spontaneous natriuresis (r = 0.7, P < 0.001). Higher pre-diuretic urine sodium to creatinine ratio (r = 0.37, P < 0.001) was the strongest predictor of post-diuretic spontaneous natriuresis. In a subgroup of patients (n = 43) randomized to protocol-driven intensified diuretic therapies, the mean diuretic-induced natriuresis increased three-fold. In contrast to the substantial decrease in spontaneous natriuresis predicted by CPDSR, no change in post-diuretic spontaneous natriuresis was observed (P = 0.47).

CONCLUSION

On a population level, CPDSR was not an important driver of diuretic resistance in hypervolemic ADHF. Contrary to CPDSR, a greater diuretic-induced natriuresis predicted a larger post-diuretic spontaneous natriuresis. Basal sodium avidity, rather than diuretic-induced CPDSR, appears to be the predominant determinate of both diuretic-induced and post-diuretic natriuresis in hypervolemic ADHF.

Sex and Heart Failure Treatment Prescription and Adherence

Heart disease is the leading cause of death in both men and women in developed countries. Heart failure (HF) contributes to significant morbidity and mortality and continues to remain on the rise. While advances in pharmacological therapies have improved its prognosis, there remain a number of unanswered questions regarding the impact of these therapies in women. Current HF guidelines recommend up-titration of neurohormonal blockade, to the same target doses in both men and women but several factors may impair achieving this goal in women: more adverse drug reactions, reduced adherence and even lack of evidence on the optimal drug dose. Systematic under-representation of women in cardiovascular drug trials hinders the identification of sex differences in the efficacy and safety of cardiovascular medications. Women are also under-represented in device therapy trials and are 30% less likely to receive a device in clinical practice. Despite presenting with fewer ventricular arrythmias and having an increased risk of implant complications, women show better response to resynchronization therapy, with lower mortality and HF hospitalizations. Fewer women receive advanced HF therapies. They have a better post-heart transplant survival compared to men, but an increased immunological risk needs to be acknowledged. Technological advances in mechanical circulatory support, with smaller and more hemocompatible devices, will likely increase their implantation in women. This review outlines current evidence regarding sex-related differences in prescription, adherence, adverse events, and prognostic impact of the main management strategies for HF.

Arrhythmias in Cardiac Sarcoidosis Bench to Bedside: A Case-Based Review

Cardiac sarcoidosis is a component of an often multiorgan granulomatous disease of still uncertain cause. It is being recognized with increasing frequency, mainly as the result of heightened awareness and new diagnostic tests, specifically cardiac magnetic resonance imaging and ¹⁸F-fluorodeoxyglucose positron emission tomography scans. The purpose of this case-based review is to highlight the potentially life-saving importance of making the early diagnosis of cardiac sarcoidosis using these new tools and to provide a framework for the optimal care of patients with this disease. We will review disease mechanisms as currently understood, associated arrhythmias including conduction abnormalities, and atrial and ventricular tachyarrhythmias, guideline-directed diagnostic criteria, screening of patients with extracardiac sarcoidosis, and the use of pacemakers and defibrillators in this setting. Treatment options, including those related to heart failure, and those which may help clarify disease mechanisms are included.

Natriuretic Equation to Predict Loop Diuretic Response in Patients With Heart Failure

BACKGROUND

Most acute decompensated heart failure admissions are driven by congestion. However, residual congestion is common and often driven by the lack of reliable tools to titrate diuretic therapy. The authors previously developed a natriuretic response prediction equation (NRPE), which predicts sodium output using a spot urine sample collected 2 h after loop diuretic administration.

OBJECTIVES

The purpose of this study was to validate the NRPE and describe proof-of-concept that the NRPE can be used to guide diuretic therapy.

METHODS

Two cohorts were assembled: 1) the Diagnosing and Targeting Mechanisms of Diuretic Resistance (MDR) cohort was used to validate the NRPE to predict 6-h sodium output after a loop diuretic, which was defined as poor (<50 mmol), suboptimal (<100 mmol), or excellent (>150 mmol); and 2) the Yale Diuretic Pathway (YDP) cohort, which used the NRPE to guide loop diuretic titration via a nurse-driven automated protocol.

RESULTS

Evaluating 638 loop diuretic administrations, the NRPE showed excellent discrimination with areas under the curve ≥0.90 to predict poor, suboptimal, and excellent natriuretic response, and outperformed clinically obtained net fluid loss (p < 0.05 for all cutpoints). In the YDP cohort (n = 161) using the NRPE to direct therapy mean daily urine output (1.8 ± 0.9 l vs. 3.0 ± 0.8 l), net fluid output (-1.1 ± 0.9 l vs. -2.1 ± 0.9 l), and weight loss (-0.3 ± 0.3 kg vs. -2.5 ± 0.3 kg) improved substantially following initiation of the YDP (p < 0.001 for all pre-post comparisons).

CONCLUSIONS

Natriuretic response can be rapidly and accurately predicted by the NRPE, and this information can be used to guide diuretic therapy during acute decompensated heart failure. Additional study of diuresis guided by the NRPE is warranted.

Sarcoid Heart Disease: an Update on Diagnosis and Management

PURPOSE OF REVIEW

The purpose of this review is to provide an update on cardiac sarcoidosis (CS) and to discuss the current recommendations and progress in diagnosis and management of this disease. Sarcoidosis is a multisystem granulomatous disease of unknown etiology. Cardiac involvement is seen in at least 25% and is associated with poor prognosis. Manifestations of cardiac sarcoidosis (CS) can vary from presence of silent myocardial granulomas, which may lead to sudden death, to symptomatic conduction abnormalities, ventricular arrhythmias, and heart failure.

RECENT FINDINGS

We discuss newer imaging modalities such as cardiac magnetic resonance imaging and positron emission tomography in conjunction with clinical criteria increasingly used for diagnosing and prognosticating patients with CS. Immunosuppression (primarily corticosteroids) is recommended for treatment of CS; however, its efficacy has never been proven in prospective randomized studies. The role of imaging to guide the use of immunotherapy is unknown. Cardiac sarcoidosis continues to challenge clinicians due to its protean presentations, lack of diagnostic standards, and data for risk stratification and treatment. There is a need for prospective, randomized controlled trials to understand how best to diagnose and treat cardiac sarcoidosis.

Differential Impact of Class I and Class II Panel Reactive Antibodies on Post-Heart Transplant Outcomes

BACKGROUND

Sensitized patients awaiting heart transplantation spend a longer time on the waitlist and have higher mortality. We are now able to further characterize sensitization by discriminating antibodies against class I and II, but the differential impact of these has not been assessed systematically.

METHODS AND RESULTS

Using United Network for Organ Sharing data (2004-2015), we analyzed 17,361 adult heart transplant patients whose class I and II panel reactive antibodies were reported. Patients were divided into 4 groups: class I and II ≤25% (group 1); class I ≤25% and class II ˃25% (group 2); class II ≤25% and class I >25% (group 3); and both class I and II >25% (group 4). Outcomes assessed were treated rejection at 1-year mortality, all-cause mortality, and rejection-related mortality. Compared with group 1, only group 4 was associated with a higher risk of treated rejection at 1 year (odds ratio 1.31, 95% confidence interval [CI] 1.05-1.64), all-cause mortality (hazard ratio 1.24, 95% CI 1.06-1.46), and mortality owing to rejection (subhazard ratio 1.84, 95% CI 1.18-2.85), whereas groups 2 and 3 were not (P > .05).

CONCLUSIONS

Combined elevation in class I and II panel reactive antibodies seem to increase the risk of treated rejection and all-cause mortality, whereas risk with isolated elevation is unclear.

Empagliflozin in Heart Failure: Diuretic and Cardiorenal Effects

BACKGROUND

Sodium-glucose cotransporter-2 inhibitors improve heart failure-related outcomes. The mechanisms underlying these benefits are not well understood, but diuretic properties may contribute. Traditional diuretics such as furosemide induce substantial neurohormonal activation, contributing to the limited improvement in intravascular volume often seen with these agents. However, the proximal tubular site of action of the sodium-glucose cotransporter-2 inhibitors may help circumvent these limitations.

METHODS

Twenty patients with type 2 diabetes mellitus and chronic, stable heart failure completed a randomized, placebo-controlled crossover study of empagliflozin 10 mg daily versus placebo. Patients underwent an intensive 6-hour biospecimen collection and cardiorenal phenotyping at baseline and again after 14 days of study drug. After a 2-week washout, patients crossed over to the alternate therapy with the above protocol repeated.

RESULTS

Oral empagliflozin was rapidly absorbed as evidenced by a 27-fold increase in urinary glucose excretion by 3 hours (P<0.0001). Fractional excretion of sodium increased significantly with empagliflozin monotherapy versus placebo (fractional excretion of sodium, 1.2±0.7% versus 0.7±0.4%; P=0.001), and there was a synergistic effect in combination with bumetanide (fractional excretion of sodium, 5.8±2.5% versus 3.9±1.9%; P=0.001). At 14 days, the natriuretic effect of empagliflozin persisted, resulting in a reduction in blood volume (-208 mL [interquartile range, -536 to 153 mL] versus -14 mL [interquartile range, -282 to 335 mL]; P=0.035) and plasma volume (-138 mL, interquartile range, -379 to 154±453 mL; P=0.04). This natriuresis was not, however, associated with evidence of neurohormonal activation because the change in norepinephrine was superior (P=0.02) and all other neurohormones were similar (P<0.34) during the empagliflozin versus placebo period. Furthermore, there was no evidence of potassium wasting (P=0.20) or renal dysfunction (P>0.11 for all biomarkers), whereas both serum magnesium (P<0.001) and uric acid levels (P=0.008) improved.

CONCLUSIONS

Empagliflozin causes significant natriuresis, particularly when combined with loop diuretics, resulting in an improvement in blood volume. However, off-target electrolyte wasting, renal dysfunction, and neurohormonal activation were not observed. This favorable diuretic profile may offer significant advantage in the management of volume status in patients with heart failure and may represent a mechanism contributing to the superior long-term heart failure outcomes observed with these agents. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03027960.

Weight change in heart failure inpatients not associated with 30-day readmission

Background: The association of weight change and short-term readmission in patients hospitalized for heart failure (HF) has not been well studied. Methods: We collected clinical and weight data from patients admitted with decompensated HF to a single center (2012-2013). We performed logistic regression to determine the association between weight change and two outcomes: a total of 30-day HF-specific readmission and 30-day all-cause readmission. Results: Admission and discharge weights were documented in 479/658 patients (73%). Weight loss >2 kg was not associated with 30-day all-cause or HF-specific readmission when compared with more modest inpatient weight change (-2 kg to +2 kg; all-cause readmission odds ratio: 0.86; CI: 0.56-1.37; HF-specific readmission odds ratio: 1.15; CI: 0.61-2.16). Conclusion: Among HF inpatients, in-hospital weight loss was not associated with 30-day all-cause or HF-specific readmission.

Quantitative interpretation of FDG PET for cardiac sarcoidosis reclassifies visually interpreted exams and potentially impacts downstream interventions

Background: FDG PET is used in cardiac sarcoidosis (CS) diagnosis and management, including decisions about initiation and titration of immunosuppression. However, optimal methods to identify sarcoidosis-related inflammation on these scans is unknown. Traditional interpretive methods for FDG PET rely on qualitative visual analysis, but quantitative techniques including standardized uptake values (SUVs) may be more specific. This study evaluated the diagnostic reclassification of FDG PET studies using quantitative versus qualitative analysis and evaluated the potential impact of reclassification on downstream management and events. Methods: Cardiac-focused FDG PET examinations performed for the evaluation of CS were analyzed, comparing results from the clinically reported visual analysis to quantitative re-analysis using left ventricular maximal SUV values (SUVmax). Net diagnostic reclassification index (NDI) was calculated and compared to admissions, deaths, ICD placements, immunosuppression initiation/escalation. Of 154 exams, 22 were reclassified from positive to negative using quantitative re-analysis whereas only 2 clinically reported negative exams were quantitatively reclassified to positive, leading to a NDI of -13.0%. In the quantitatively negative/clinically reported positive group, 11 patients had immunosuppression adjusted after 22 exams and 4 ICDs were placed. Conclusions: Quantitative re-analysis of FDG PET for CS led to an overall negative diagnostic reclassification from positive to negative. Studies that were clinically reported as positive by visual analysis but reclassified as negative by quantitative analysis had numerous medical interventions but few clinical events. The low event rate suggests the use of quantitative interpretation of FDG PET for CS may help in providing providers with a more targeted therapeutic framework. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 342-353).

Access and Outcomes Among Hypertrophic Cardiomyopathy Patients in a Large Integrated Health System

Background

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiomyopathy. Current guidelines endorse management in expert centers, but patient socioeconomic status can affect access to specialty care. The effect of socioeconomic status and specialty care access on HCM outcomes has not been examined.

Methods and Results

We conducted a retrospective cohort study that examined outcomes among HCM patients receiving care in the Yale New Haven Health System between June 2011 and December 2017. Patients were assigned to lower or higher socioeconomic status groups (LSES/HSES) based on medical insurance provider and to receivers of specialty care (SC) at Yale's Inherited Cardiomyopathy clinic or general cardiology care (GC). The primary outcome was all‐cause death, and the secondary outcome was all‐cause hospitalization. We identified 953 HCM patients; 820 (86%) were HSES and 133 (14%) were LSES. Forty‐three (4.5%) patients died from cardiac and noncardiac causes. LSES patients within the general cardiology care cohort had significantly higher all‐cause mortality compared with HSES patients (adjusted hazard ratio, [95% CI]=10.06 [4.38–23.09]; P<0.001). This was not noted in the specialty care cohort (adjusted hazard ratio, [95% CI]=2.87 [0.56–14.73]; P=0.21). The moderator effect of specialty care on mortality difference between LSES versus HSES, however, did not reach statistical significance (hazard ratio, 0.29 [0.05–1.77]; P=0.18). Specialist care was associated with increased hospitalization (adjusted hazard ratio, [95% CI]=3.28 [1.11–9.73]; P=0.03 for LSES; 2.19 [1.40–3.40]; P=0.001 for HSES).

Conclusions

Socioeconomically vulnerable HCM patients had higher mortality when not referred to specialty care. Further study is needed to understand the underlying causes.

Usefulness of Intra-aortic Balloon Pump in Patients With Cardiogenic Shock

Predictors of survival in cardiogenic shock (CS) treated with intra-aortic balloon pump (IABP) are not clearly understood. In this retrospective study, we sought to evaluate patient characteristics and impact of timing of IABP in treatment of CS. Patients presenting to the Yale New Haven Hospital in CS who received IABP between February 2013 and April 2017 were included in the study. We assessed baseline characteristics and clinical predictors of 30-day mortality. Hundred ninety-three (n = 193) patients were included in this study. Mean age was 68.8 ± 14.5 years. Thirty percent (30%) were women, 38% had cardiac arrest, and left ventricular ejection fraction was 33.7 ± 14.9%. Overall 30-day mortality was 36%. Thirty-day mortality was 24% when IABP was placed within less than 1 hour of onset of CS versus 49% when implanted ≥1 hour after recognition of CS (p = 0.001). Mortality was 18%, 21%, 36%, and 74% for patient requiring 0, 1, 2, and 3 or more inotropes after IABP placement (p < 0.001). In multivariate analysis, advancing age, cardiac arrest on presentation, time to IABP implantation, and number of inotropes needed after IABP implantation predicted 30-day mortality. In the 193 patients, 134 (69.4%) presented with CS from ACS and 59 (30.6%) with CS from non-ACS-related causes. No difference in mortality was noted between the ACS and non-ACS groups 34.3% versus 40.7% (p = 0.39). In conclusion, early use of IABP in CS was associated with significant improvement in 30-day mortality regardless of the etiology of CS. Continued need for significant inotropic support after IABP is associated with worse prognosis and maybe used as an indicator for need to escalate to higher levels of support.

Evolving Concepts in Diagnosis and Management of Cardiogenic Shock

Despite efforts at early revascularization in acute coronary syndrome and advancing technologies in the field of temporary mechanical circulatory support (TMCS), the mortality from cardiogenic shock (CS) remains very high. Treatment of these patients involves understanding the trajectory of the condition and making complex decisions regarding the appropriate selection of medical and device therapies. The current definition of CS is not universally applicable and defines shock in absolute terms. CS should be thought of as a continuum rather than a binary diagnosis and is best defined as a clinical syndrome of tissue hypoperfusion resulting from cardiac dysfunction. Early intervention with appropriate timing and selection of apposite TMCS device may be the key to improving outcomes. TMCS device selection is a complex process requiring consideration of the severity of CS, patient-specific risks, technical limitations, overall goals of care, and assessment of futility of care. In this review, we discuss identification and pathophysiology of CS, and critically review acute management strategies, both medical and mechanical therapies and outline areas that need further investigation.

Hypochloremia and Diuretic Resistance in Heart Failure: Mechanistic Insights

BACKGROUND

Recent epidemiological studies have implicated chloride, rather than sodium, as the driver of poor survival previously attributed to hyponatremia in heart failure. Accumulating basic science evidence has identified chloride as a critical factor in renal salt sensing. Our goal was to probe the physiology bridging this basic and epidemiological literature.

METHODS AND RESULTS

Two heart failure cohorts were included: (1) observational: patients receiving loop diuretics at the Yale Transitional Care Center (N=162) and (2) interventional pilot: stable outpatients receiving ≥80 mg furosemide equivalents were studied before and after 3 days of 115 mmol/d supplemental lysine chloride (N=10). At the Yale Transitional Care Center, 31.5% of patients had hypochloremia (chloride ≤96 mmol/L). Plasma renin concentration correlated with serum chloride (r=-0.46; P<0.001) with no incremental contribution from serum sodium (P=0.49). Hypochloremic versus nonhypochloremic patients exhibited renal wasting of chloride (P=0.04) and of chloride relative to sodium (P=0.01), despite better renal free water excretion (urine osmolality 343±101 mOsm/kg versus 475±136; P<0.001). Hypochloremia was associated with poor diuretic response (odds ratio, 7.3; 95% confidence interval, 3.3-16.1; P<0.001). In the interventional pilot, lysine chloride supplementation was associated with an increase in serum chloride levels of 2.2±2.3 mmol/L, and the majority of participants experienced findings such as hemoconcentration, weight loss, reduction in amino terminal, pro B-type natriuretic peptide, increased plasma renin activity, and increased blood urea nitrogen to creatinine ratio.

CONCLUSIONS

Hypochloremia is associated with neurohormonal activation and diuretic resistance with chloride depletion as a candidate mechanism. Sodium-free chloride supplementation was associated with increases in serum chloride and changes in several cardiorenal parameters.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02031354.

Pathophysiology of heart failure and frailty: a common inflammatory origin?

Frailty, a clinical syndrome that typically occurs in older adults, implies a reduced ability to tolerate biological stressors. Frailty accompanies many age‐related diseases but can also occur without overt evidence of end‐organ disease. The condition is associated with circulating inflammatory cytokines and sarcopenia, features that are shared with heart failure (HF). However, the biological underpinnings of frailty remain unclear and the interaction with HF is complex. Here, we describe the inflammatory pathophysiology that is associated with frailty and speculate that the inflammation that occurs with frailty shares common origins with HF. We discuss the limitations in investigating the pathophysiology of frailty due to few relevant experimental models. Leveraging current therapies for advanced HF and current known therapies to address frailty in humans may enable translational studies to better understand the inflammatory interactions between frailty and HF.

Renal tubular resistance is the primary driver for loop diuretic resistance in acute heart failure

BACKGROUND

Loop diuretic resistance is a common barrier to effective decongestion in acute heart failure (AHF), and is associated with poor outcome. Specific mechanisms underlying diuretic resistance are currently unknown in contemporary AHF patients. We therefore aimed to determine the relative importance of defects in diuretic delivery vs. renal tubular response in determining diuretic response (DR) in AHF.

METHODS AND RESULTS

Fifty AHF patients treated with intravenous bumetanide underwent a 6-h timed urine collection for sodium and bumetanide clearance. Whole-kidney DR was defined as sodium excreted per doubling of administered loop diuretic and represents the sum of defects in drug delivery and renal tubular response. Tubular DR, defined as sodium excreted per doubling of renally cleared (urinary) loop diuretic, captures resistance specifically in the renal tubule. Median administered bumetanide dose was 3.0 (2.0-4.0) mg with 52 (33-77)% of the drug excreted into the urine. Significant between-patient variability was present as the administered dose only explained 39% of variability in the quantity of bumetanide in urine. Cumulatively, factors related to drug delivery such as renal bumetanide clearance, administered dose, and urea clearance explained 28% of the variance in whole-kidney DR. However, resistance at the level of the renal tubule (tubular DR) explained 71% of the variability in whole-kidney DR.

CONCLUSION

Defects at the level of the renal tubule are substantially more important than reduced diuretic delivery in determining diuretic resistance in patients with AHF.