When the Heart Runs Out of Heartbeats

Optimization of a Screw Centrifugal Blood Pump Based on Random Forest and Multi-Objective Gray Wolf Optimization Algorithm

The centrifugal blood pump is a commonly used ventricular assist device. It can replace part of the heart function, pumping blood throughout the body in order to maintain normal function. However, the high shear stress caused by the impeller rotating at high speeds can lead to hemolysis and, as a consequence, to stroke and other syndromes. Therefore, reducing the hemolysis level while ensuring adequate pressure generation is key to the optimization of centrifugal blood pumps. In this study, a screw centrifugal blood pump was used as the research object. In addition, pressure generation and the hemolysis level were optimized simultaneously using a coupled algorithm composed of random forest (RF) and multi-objective gray wolf optimization (MOGWO). After verifying the prediction accuracy of the algorithm, three optimized models were selected and compared with the baseline model in terms of pressure cloud, 2D streamline, SSS distribution, HI distribution, and vortex distribution. Finally, via a comprehensive evaluation, the optimized model was selected as the final optimization design, in which the pressure generation increased by 24% and the hemolysis value decreased by 48%.

Prognostic Value of Natriuretic Peptides for All-Cause Mortality, Right Ventricular Failure, Major Adverse Events, and Myocardial Recovery in Advanced Heart Failure Patients Receiving a Left Ventricular Assist Device: A Systematic Review

Aims: Major adverse event (MAE) rates during left ventricular assist device (LVAD) therapy in advanced heart failure (HF) patients are high, and impair quality of life and survival. Prediction and risk stratification of MAEs in order to improve patient selection and thereby outcome during LVAD therapy is therefore warranted. Circulating natriuretic peptides (NPs) are strong predictors of MAEs and mortality in chronic HF patients. However, whether NPs can identify patients who are at risk of MAEs and mortality or tend toward myocardial recovery after LVAD implantation is unclear. The aim of this systematic review is to analyze the prognostic value of circulating NP levels before LVAD implantation for all-cause mortality, MAEs and myocardial recovery after LVAD implantation.

Methods and Results: Electronic databases were searched for studies analyzing circulating NP in adults with advanced HF before LVAD implantation in relation to mortality, MAEs, or myocardial recovery after LVAD implantation. Twenty-four studies published between 2008 and 2021 were included. Follow-up duration ranged from 48 hours to 5 years. Study sample size ranged from 14 to 15,138 patients. Natriuretic peptide levels were not predictive of all-cause mortality. However, NPs were predictive of right ventricular failure (RVF) and MAEs such as ventricular arrhythmias, moderate or severe aortic regurgitation, and all-cause rehospitalization. No relation between NPs and myocardial recovery was found.

Conclusion: This systematic review found that NP levels before LVAD implantation are not predictive of all-cause mortality after LVAD implantation. Thus, NP levels may be of limited value in patient selection for LVAD therapy. However, NPs help in risk stratification of MAEs and may be used to identify patients who are at risk for RVF, ventricular arrhythmias, moderate or severe aortic regurgitation, and all-cause rehospitalization after LVAD implantation.

Changes in Use of Left Ventricular Assist Devices as Bridge to Transplantation With New Heart Allocation Policy

OBJECTIVES

The goal of this study was to describe outcomes of patients with bridge to heart transplantation (BTT) after changes were made to the donor heart allocation system.

BACKGROUND

Left ventricular assist devices (LVADs) have been used as a BTT. On October 18, 2018, the donor heart allocation system in the United States was updated.

METHODS

This study identified adults in the United Network for Organ Sharing database with durable, continuous-flow LVAD at listing or implanted while listed between April 2017 and April 2020. Baseline recipient and donor characteristics, waitlist survival, and post-transplantation outcomes were compared pre- and post-allocation system change.

RESULTS

A total of 1,794 patients met inclusion criteria: 983 in the pre-change period and 814 afterward. The number of patients listed with LVAD decreased nationally over time from 102 in April 2017 to 12 in April 2020 (p < 0.001). The proportion of patients with LVAD at time of transplant decreased from 47% to 14%. Before the change, the majority were Status 1A (75.8%) at transplantation; afterward, most were Status 2/3 (67.8%). Transplantation rates were not different (85.4% vs. 83.6%; p = 0.225), but waitlist time decreased in the post period (82 vs. 65 days; p = 0.004). Donors were more likely to be high risk (39.0% vs. 32.2%; p = 0.005), and both ischemic times and distance traveled increased (3.4 h vs. 3.1 h; p < 0.001; 199 miles vs. 82 miles; p < 0.001). Waitlist survival did not change, but post-transplantation survival was worse in patients with BTT post-change (p < 0.001).

CONCLUSIONS

The number of patients with BTT on the transplant list decreased steadily and dramatically after the allocation system change. Although time to transplant decreased, there was an increase in post-transplant mortality. These data suggest that the risks and benefits of LVAD implantation as a BTT have changed under the new allocation system and that the appropriate indication for this treatment strategy warrants a re-evaluation.

Effect of Inotropes on Patient-Reported Health Status in End-Stage Heart Failure: A Review of Published Clinical Trials

BACKGROUND

A growing population of patients with end-stage heart failure (HF) with reduced ejection fraction has limited treatment options to improve their quality and quantity of life. Although positive inotropes have failed to show survival benefit, these agents may enhance patient-reported health status, that is, symptoms, functional status, and health-related quality of life. We sought to review the available clinical trial data on positive inotrope use in patients with end-stage HF and to summarize evidence supporting the use of these agents to improve health status of patients with end-stage HF.

METHODS

A literature review of randomized controlled trials examining the use of positive inotropy in HF with reduced ejection fraction was conducted. We searched MEDLINE, SCOPUS, and Web of Science between January 1980 to December 2018 for randomized controlled trials that used as their main outcome measures the effects of inotrope therapy on (1) morbidity/mortality, (2) symptoms, (3) functional status, or (4) health-related quality of life. Inotropes of interest included adrenergic agents, phosphodiesterase inhibitors, calcium sensitizers, myosin activators, and SERCA2a (sarcoplasmic reticulum Ca²⁺-ATPase) modulators.

RESULTS

Twenty-two out of 26 inotrope randomized controlled trials measured the effect of inotropes on at least one patient-reported health status domain. Among the 22 studies with patient-related health status outcomes, 11 (50%) gauged symptom response, 15 (68%) reported functional capacity changes, and 12 (54%) reported health-related quality of life measures. Fourteen (64%) of these trials noted positive outcomes in at least one health status domain measured; 11 (79%) of these positive studies used agents that worked through phosphodiesterase inhibition.

CONCLUSIONS

There has been a lack of standardization surrounding measurement of patient-centered outcomes in studies of inotropes for end-stage HF with reduced ejection fraction. The degree to which positive inotropes can improve patient-reported health status and the adverse risk they pose remains unknown.

Neurohormonal Blockade and Clinical Outcomes in Patients With Heart Failure Supported by Left Ventricular Assist Devices

Importance

Left ventricular assist devices (LVADs) improve outcomes in patients with advanced heart failure, but little is known about the role of neurohormonal blockade (NHB) in treating these patients.

Objective

To analyze the association between NHB blockade and outcomes in patients with LVADs.

Design, Setting, and Participants

This retrospective cohort analysis of the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) included patients from more than 170 centers across the United States and Canada with continuous flow LVADs from 2008 to 2016 who were alive with the device in place at 6 months after implant. The data were analyzed between February and November 2019.

Exposures

Patients were stratified based on exposure to NHB and represented all permutations of the following drug classes: angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, β-blockers, and mineralocorticoid antagonists.

Main Outcomes and Measures

The outcomes of interest were survival at 4 years and quality of life at 2 years based on Kansas City Cardiomyopathy Questionnaire scores and a 6-minute walk test.

Results

A total of 12 144 patients in INTERMACS met inclusion criteria, of whom 2526 (20.8% ) were women, 8088 (66.6%) were white, 3024 (24.9%) were African American, and 753 (6.2%) were Hispanic; the mean (SD) age was 56.8 (12.9) years. Of these, 10 419 (85.8%) were receiving NHB. Those receiving any NHB medication at 6 months had a better survival rate at 4 years compared with patients not receiving NHB (56.0%; 95% CI, 54.5%-57.5% vs 43.9%; 95% CI, 40.5%-47.7%). After sensitivity analyses with an adjusted model, this trend persisted with patients receiving triple therapy with an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker, β-blocker, and mineralocorticoid antagonist having the lowest hazard of death compared with patients in the other groups (hazard ratio, 0.34; 95% CI, 0.28-0.41). Compared with patients not receiving NHB, use of NHB was associated with a higher Kansas City Cardiomyopathy Questionnaire score (66.6; bootstrapped 95% CI, 65.8-67.3 vs 63.0; bootstrapped 95% CI, 60.1-65.8; P = .02) and a 6-minute walk test (1103 ft; bootstrapped 95% CI, 1084-1123 ft vs 987 ft; bootstrapped 95% CI, 913-1060 ft; P < .001).

Conclusions and Relevance

Among patients with LVADs who tolerated NHB therapy, continued treatment was associated with improved survival and quality of life. The optimal heart failure regimen for patients after LVAD implant may be the initiation and continuation of guideline-directed medical therapy.

Clinical implications of differences between real world and clinical trial usage of left ventricular assist devices for end stage heart failure

Importance

Patient outcomes in heart failure clinical trials are generally better than those observed in real-world settings. This may be related to stricter inclusion and exclusion criteria in clinical trials.

Objective

We study sought to characterize the clinical implications of differences between patients in clinical trials and those in a real-world registry of patients receiving left ventricular assist devices (LVADs).

Design, setting, and participants

This retrospective cohort study included all patients in INTERMACS (the Interagency Registry for Mechanically Assisted Circulatory Support) who were implanted with an axial flow LVAD from 2010 to 2015 to allow for equivalent comparisons.

Main outcomes and measures

Differences in patient characteristics and 2-year rates of adverse outcomes with those reported in the ENDURANCE and MOMENTUM 3 clinical trials. Survival analyses were used to assess the relationships between prespecified patient factors and clinical outcomes.

Results

Of the 10,937 LVAD recipients identified in INTERMACS between 2010–2015, 44% met at least 1 clinical trial exclusion criterion. The 2-year incidence of stroke and death amongst LVAD recipients in INTERMACS and the landmark clinical trials differed significantly (P<0.04, both). Nevertheless, patients who would have been excluded from the clinical trials did not have dramatically different 2-year mortality outcomes in INTERMACS [2y survival estimate: 66.4%, 95% CI (64.9–67.9%) versus 71.9%, 95% CI (70.6–73.1%)]. Clinical interventions driving a significantly increased risk of death were relatively rare (<5% of implants) and included mechanical ventilation, ECMO, severe thrombocytopenia, and dialysis.

Conclusions and relevance

Most exclusion criteria used in LVAD clinical trials did not afford a substantially greater risk to patients in the real-world setting. In the relatively infrequent cases of end stage renal disease, thrombocytopenia, respiratory failure, and need for ECMO, the risks and benefits of LVAD therapy need careful weighting and further study.

Effect of the Creatinine Excretion Rate Index, a Marker of Sarcopenia, on Prediction of Intracranial Hemorrhage in Patients With Advanced Heart Failure and a Continuous-Flow Left Ventricular Assist Device

BACKGROUND

Sarcopenia is characterized by progressive loss of skeletal muscle and has frequently been associated with poor clinical outcomes in patients with advanced heart failure (HF). The urinary creatinine excretion rate (CER) index is an easily measured marker of muscle mass, but its predictive capacity for mortality and cerebrovascular events has not been investigated in patients with a continuous-flow implantable left ventricular assist device (CF-iLVAD).

METHODS AND RESULTS

We retrospectively reviewed 147 patients (mean [±SD] age 43.7±12.5 years, 106 male) who underwent CF-iLVAD implantation between April 2011 and June 2019. CER indices in 24-h urine samples before CF-iLVAD implantation were determined. Over a median follow-up of 2.3 years, there were 10 (6.8%) deaths and 43 (29.3%) cerebrovascular events. Patients were divided into 2 groups (low and high CER index) according to the median CER index in men and women (i.e., 13.71 and 12.06 mg·kg-1·day-1, respectively). Mortality and intracranial hemorrhage rates after CF-iLVAD implantation were significantly higher in the low than high CER index group (mortality 12.3% vs. 1.4% [P<0.01]; intracranial hemorrhage 23.3% vs. 8.1% [P=0.01]). Multivariate Cox proportional hazard models revealed that a low CER index was an independent predictor of intracranial hemorrhage in patients receiving a CF-iLVAD (hazard ratio 3.63; 95% confidence interval 1.43-9.24; P<0.01).

CONCLUSIONS

A low preoperative CER index is an independent, non-invasive predictor of intracranial hemorrhage after CF-iLVAD implantation.

Why has positive inotropy failed in chronic heart failure? Lessons from prior inotrope trials

Current pharmacological therapies for heart failure with reduced ejection fraction are largely either repurposed anti‐hypertensives that blunt overactivation of the neurohormonal system or diuretics that decrease congestion. However, they do not address the symptoms of heart failure that result from reductions in cardiac output and reserve. Over the last few decades, numerous attempts have been made to develop and test positive cardiac inotropes that improve cardiac haemodynamics. However, definitive clinical trials have failed to show a survival benefit. As a result, no positive inotrope is currently approved for long‐term use in heart failure. The focus of this state‐of‐the‐art review is to revisit prior clinical trials and to understand the causes for their findings. Using the learnings from those experiences, we propose a framework for future trials of such agents that maximizes their potential for success. This includes enriching the trials with patients who are most likely to derive benefit, using biomarkers and imaging in trial design and execution, evaluating efficacy based on a wider range of intermediate phenotypes, and collecting detailed data on functional status and quality of life. With a rapidly growing population of patients with advanced heart failure, the epidemiologic insignificance of heart transplantation as a therapeutic intervention, and both the cost and morbidity associated with ventricular assist devices, there is an enormous potential for positive inotropic therapies to impact the outcomes that matter most to patients.

Essential Elements of Early Post Discharge Care of Patients with Heart Failure

PURPOSE OF REVIEW

Heart failure is associated with an enormous burden on both patients and health care systems in the USA. Several national policy initiatives have focused on improving the quality of heart failure care, including reducing readmissions following hospitalization, which are common, costly, and, at least in part, preventable. The transition from inpatient to ambulatory care setting and the immediate post-hospitalization period present an opportunity to further optimize guideline concordant medical therapy, identify reversible issues related to worsening heart failure, and evaluate prognosis. It can also provide opportunities for medication reconciliation and optimization, consideration of device-based therapies, appropriate management of comorbidities, identification of individual barriers to care, and a discussion of goals of care based on prognosis.

RECENT FINDINGS

Recent studies suggest that attention to detail regarding patient comorbidities, barriers to care, optimization of both diuretic and neurohormonal therapies, and assessment of prognosis improve patient outcomes. Despite the fact that the transition period appears to be an optimal time to address these issues in a comprehensive manner, most patients are not referred to programs specializing in this approach post hospital discharge. The objective of this review is to provide an outline for early post discharge care that allows clinicians and other health care providers to care for these heart failure patients in a manner that is both firmly rooted in the guidelines and patient-centered. Data regarding which intervention is most likely to confer benefit to which subset of patients with this disease is lacking and warrants further study.

Plasma Levels of MicroRNA-155 Are Upregulated with Long-Term Left Ventricular Assist Device Support

Left ventricular assist device (LVAD) therapy unloads the failing heart but exposes the human body to unique pathophysiologic demands such as continuous blood flow and complete univentricular support, which are associated with increased risk of adverse clinical outcomes. MicroRNAs (miRNAs) are 22-23 nucleotide RNAs involved in regulation of multiple biologic processes including the pathogenesis of heart failure (HF). Thus, measurement of miRNAs may have potential in both diagnostics as circulating biomarkers and in therapeutics for targeted interventions. We examined 23 distinct miRNAs that have previously been shown to play a role in HF pathogenesis and measured them in 40 individuals both before continuous-flow LVAD implantation and at a median of 96.5 days after implantation. Quantitative real-time polymerase chain reaction was performed for miRNA amplification, and 19 miRs were included in statistical analysis. Wilcoxon signed-rank tests were used to compare within-patient median relative quantification values pre- and post-LVAD placement. The median age of patients was 67 years, and 57.5% were at Interagency Registry for Mechanically Assisted Circulatory Support level 1-2. After LVAD support, only miR-155 was found to be statistically significant (p < 0.002), with an upregulation in plasma expression levels with LVAD support, which persisted regardless of the direction of change in serial HF biomarker levels. MicroRNA-155, which has been shown to play a central role in inflammation and neovascularization, was upregulated with long-term LVAD support. If validated by future studies, miR-155 may help further inform on underlying LVAD physiology and has a role as a therapeutic target in this patient population.

Role of Biomarkers for the Prevention, Assessment, and Management of Heart Failure: A Scientific Statement From the American Heart Association

BACKGROUND AND PURPOSE

Natriuretic peptides have led the way as a diagnostic and prognostic tool for the diagnosis and management of heart failure (HF). More recent evidence suggests that natriuretic peptides along with the next generation of biomarkers may provide added value to medical management, which could potentially lower risk of mortality and readmissions. The purpose of this scientific statement is to summarize the existing literature and to provide guidance for the utility of currently available biomarkers.

METHODS

The writing group used systematic literature reviews, published translational and clinical studies, clinical practice guidelines, and expert opinion/statements to summarize existing evidence and to identify areas of inadequacy requiring future research. The panel reviewed the most relevant adult medical literature excluding routine laboratory tests using MEDLINE, EMBASE, and Web of Science through December 2016. The document is organized and classified according to the American Heart Association to provide specific suggestions, considerations, or contemporary clinical practice recommendations.

RESULTS

A number of biomarkers associated with HF are well recognized, and measuring their concentrations in circulation can be a convenient and noninvasive approach to provide important information about disease severity and helps in the detection, diagnosis, prognosis, and management of HF. These include natriuretic peptides, soluble suppressor of tumorgenicity 2, highly sensitive troponin, galectin-3, midregional proadrenomedullin, cystatin-C, interleukin-6, procalcitonin, and others. There is a need to further evaluate existing and novel markers for guiding therapy and to summarize their data in a standardized format to improve communication among researchers and practitioners.

CONCLUSIONS

HF is a complex syndrome involving diverse pathways and pathological processes that can manifest in circulation as biomarkers. A number of such biomarkers are now clinically available, and monitoring their concentrations in blood not only can provide the clinician information about the diagnosis and severity of HF but also can improve prognostication and treatment strategies.

Outcomes of patients with right ventricular failure on milrinone after left ventricular assist device implantation

Previous studies have grouped together both patients requiring right ventricular assist devices (RVADs) with patients requiring prolonged milrinone therapy after left ventricular assist device (LVAD) implantation. We retrospectively identified 149 patients receiving LVADs and 18 (12.1%) of which developed right ventricular (RV) failure. We then separated these patients into those requiring RVADs versus prolonged milrinone therapy. This included 10 patients who were treated with prolonged milrinone and eight patients who underwent RVAD placement. Overall, the RV failure group had worse survival compared with the non-RV failure cohort (p = 0.038). However, this was only for the subgroup of patients who required RVADs, who had a 1, 6, 12, and 24 month survival of 62.5%, 37.5%, 37.5%, and 37.5%, respectively, versus 96.8%, 92.1%, 86.7%, and 84.4% for patients without RV failure (p < 0.001). Patients treated with prolonged milrinone therapy for RV failure had similar survivals compared with patients without RV failure. In the RV failure group, age, preoperative renal failure, and previous cardiac surgery were predictors of the need for prolonged postoperative milrinone. As LVADs become a more widely used therapy for patients with refractory, end-stage heart failure, it will be important to reduce the incidence of RV failure, as it yields significant morbidity and increases cost.

Copeptin in Heart Failure

Heart failure (HF) is one of the most common causes of hospitalization and mortality in the modern Western world and an increasing proportion of the population will be affected by HF in the future. Although HF management has improved quality of life and prognosis, mortality remains very high despite therapeutic options. Medical management consists of a neurohormonal blockade of an overly activated neurohormonal axis. No single marker has been able to predict or monitor HF with respect to disease progression, hospitalization, or mortality. New methods for diagnosis, monitoring therapy, and prognosis are warranted. Copeptin, a precursor of pre-provasopressin, is a new biomarker in HF with promising potential. Copeptin has been found to be elevated in both acute and chronic HF and is associated with prognosis. Copeptin, in combination with other biomarkers, could be a useful marker in the monitoring of disease severity and as a predictor of prognosis and survival in HF.

Effects of left ventricular assist device support on biomarkers of cardiovascular stress, fibrosis, fluid homeostasis, inflammation, and renal injury

OBJECTIVES

The purpose of this study was to examine changes in a broad panel of biomarkers following left ventricular assist device (LVAD) support in advanced heart failure (HF).

BACKGROUND

LVAD therapy mechanically unloads the failing heart and may result in reversal of certain aspects of the end-stage HF phenotype. Changes in markers of myocardial stress, fibrosis, inflammation, fluid homeostasis, and renal injury in this setting are unknown.

METHODS

Amino-terminal pro-B-type natriuretic peptide (NT-proBNP), galectin-3, ST2, copeptin, growth differentiation factor (GDF)-15, C-reactive protein (CRP), and neutrophil gelatinase associated lipocalin (NGAL) levels were measured in frozen plasma collected from 37 individuals prior to continuous flow LVAD implantation and a median of 136 (interquartile range: 94 to 180) days after implantation.

RESULTS

The median age of patients was 68 years old. LVAD therapy was associated with significant decreases in NT-proBNP (3,093 to 2,090 pg/ml; p = 0.02), ST2 (67.5 to 45.2 ng/ml, p <0.01), galectin-3 (24.7 to 22.0 ng/ml; p = 0.04), GDF-15 (3,232 to 2,613 ng/l;p <0.001), hs-CRP (22.4 to 11.9 mg/l; p = 0.01), and copeptin (103 to 94 pmol/l; p = 0.003) but not NGAL (132 to 135 ng/ml; p = 0.06). Despite improvement over time, absolute values of each biomarker remained extremely abnormal. Greater reductions in biomarkers were noted in individuals with >25% decrease in NT-proBNP concentrations but reached statistical significance only in the case of galectin-3 (p = 0.01).

CONCLUSIONS

The biomarker profile in patients after LVAD placement improves but nonetheless remains significantly abnormal. Our results suggest the need for targeted therapeutic interventions to mitigate such abnormalities and potentially increase rates of myocardial recovery.

Are peripherally inserted central catheters associated with increased risk of adverse events in status 1B patients awaiting transplantation on continuous intravenous milrinone?

BACKGROUND

Peripherally inserted central catheters (PICCs) are used to deliver continuous intravenous (IV) milrinone in stage D heart failure (HF) patients awaiting heart transplantation (HT).

METHODS

We retrospectively analyzed PICC adverse events (AEs) and associated cost in 129 status 1B patients from 2005 to 2012. End points were HT, left ventricular assist device (LVAD), and death. Regression analysis was used to identify AE risk factors.

RESULTS

Fifty-three PICC AEs occurred in 35 patients (27%), consisting of 48 infections, 4 thromboses, and 1 bleeding event. Median duration of PICC support was 63 (interquartile range [IQR] 34-131) days, and median time to first PICC infection was 44 (IQR 14-76) days. Among PICC infections, 9% required defibrillator removal and 30% were inactivated on the HT list for a mean of 23 ± 17 days. Rate of HT, LVAD, or death was similar between groups (P > .05). Regression analysis found that a double lumen PICC was associated with a shorter time to first PICC infection (hazard ratio 7.59, 95% CI 1.97-29.23; P = .003). Median cost per PICC infection was $10,704 (IQR $7,401-$26,083).

CONCLUSIONS

PICC infections were the most frequent AEs. PICCs with >1 lumen were associated with increased risk of infection. PICC AEs accounted for increased intensive care unit admissions, HT list inactivations, and overall cost.

Elevation of Plasma Milrinone Concentrations in Stage D Heart Failure Associated With Renal Dysfunction

Purpose:

To determine steady state milrinone concentrations in patients with stage D heart failure (HF) with and without renal dysfunction

Methods:

We retrospectively identified patients with stage D HF at a single medical center on continuous milrinone infusion at the time of plasma collection for entry into a research registry database. Milrinone was prescribed and titrated to improve hemodynamic and clinical status by a cardiologist. Plasma samples were obtained at steady state milrinone concentrations. Patients were stratified by creatinine clearance (CrCl) into 4 groups: group 1 (CrCl >60 mL/min), group 2 (CrCl 60-30 mL/min), group 3 (CrCl <30 mL/min), and group 4 (intermittent hemodialysis). Retrospective chart review was performed to quantify the postmilrinone hemodynamic changes by cardiac catheterization and electrophysiologic changes by implantable cardiac defibrillator (ICD) interrogation.

Results:

A total of 29 patients were identified: group 1 (n = 14), group 2 (n = 10), group 3 (n = 3), and group 4 (n = 2). The mean infusion rate (0.391 ± 0.08 µg/kg/min) did not differ between groups ( P = 0.14). The mean milrinone concentration was 451± 243 ng/mL in group 1, 591 ± 293 ng/mL in group 2, 1575 ± 962 ng/mL in group 3, and 6252 ± 4409 ng/mL in group 4 ( P<0.05 compared to groups 1). There was no difference in postmilrinone hemodynamic improvements between the groups ( P=0.41). The ICD interrogation revealed limited comparisons, but 6 of the 8 postmilrinone ventricular tachycardia episodes requiring defibrillation occurred in group 4 patients.

Conclusion:

Patients with stage D HF having severe renal dysfunction have elevated milrinone concentrations. Future studies of milrinone concentrations are warranted to investigate the potential risk of life-threatening arrhythmias and potential dosing regimens in renal dysfunction.