One-year retrospective analysis of anti-FXa apixaban and rivaroxaban levels demonstrates utility for management decisions in various urgent and nonurgent clinical situations

OBJECTIVES

Quantification of direct oral anticoagulant (DOAC) plasma levels can guide clinical management, but insight into clinical scenarios surrounding DOAC-calibrated anti-FXa assays is limited.

METHODS

Apixaban- and rivaroxaban-calibrated chromogenic anti-Xa assays performed over a 1-year period were retrospectively analyzed. Patient demographics, DOAC history, concomitant medications, and renal/liver comorbidities were obtained. Indications for testing and associated clinical actions were reviewed. Machine learning (ML) models predicting clinical actions were evaluated.

RESULTS

In total, 371 anti-FXa apixaban and 89 anti-FXa rivaroxaban tests were performed for 259 and 67 patients in recurring urgent (acute bleeding, unplanned procedures) and nonurgent situations, including several scenarios not captured by existing testing recommendations (eg, drug monitoring, recurrent thromboembolic events, bleeding tendency). In urgent settings, andexanet reversal was guided by radiologic and clinical findings over DOAC levels in 14 of 32 instances, while 51% of apixaban patients qualified for nonreversal strategies through the availability of levels. Levels also informed procedure/intervention timing and supported management decisions when DOAC clearance or DOAC target levels were in question. The importance of clinical context was emphasized by exploratory ML models predicting particular clinical actions.

CONCLUSIONS

Although clinical situations are complex, DOAC testing facilitates clinical decision-making, including reversal, justifying more widespread implementation of these assays.

Virtual Care Team Guided Management of Patients With Heart Failure During Hospitalization

BACKGROUND

Scalable and safe approaches for heart failure guideline-directed medical therapy (GDMT) optimization are needed.

OBJECTIVES

The authors assessed the safety and effectiveness of a virtual care team guided strategy on GDMT optimization in hospitalized patients with heart failure with reduced ejection fraction (HFrEF).

METHODS

In a multicenter implementation trial, we allocated 252 hospital encounters in patients with left ventricular ejection fraction ≤40% to a virtual care team guided strategy (107 encounters among 83 patients) or usual care (145 encounters among 115 patients) across 3 centers in an integrated health system. In the virtual care team group, clinicians received up to 1 daily GDMT optimization suggestion from a physician-pharmacist team. The primary effectiveness outcome was in-hospital change in GDMT optimization score (+2 initiations, +1 dose up-titrations, -1 dose down-titrations, -2 discontinuations summed across classes). In-hospital safety outcomes were adjudicated by an independent clinical events committee.

RESULTS

Among 252 encounters, the mean age was 69 ± 14 years, 85 (34%) were women, 35 (14%) were Black, and 43 (17%) were Hispanic. The virtual care team strategy significantly improved GDMT optimization scores vs usual care (adjusted difference: +1.2; 95% CI: 0.7-1.8; P < 0.001). New initiations (44% vs 23%; absolute difference: +21%; P = 0.001) and net intensifications (44% vs 24%; absolute difference: +20%; P = 0.002) during hospitalization were higher in the virtual care team group, translating to a number needed to intervene of 5 encounters. Overall, 23 (21%) in the virtual care team group and 40 (28%) in usual care experienced 1 or more adverse events (P = 0.30). Acute kidney injury, bradycardia, hypotension, hyperkalemia, and hospital length of stay were similar between groups.

CONCLUSIONS

Among patients hospitalized with HFrEF, a virtual care team guided strategy for GDMT optimization was safe and improved GDMT across multiple hospitals in an integrated health system. Virtual teams represent a centralized and scalable approach to optimize GDMT.

Heparin-induced thrombocytopenia in end-stage renal disease: Reliability of the PF4-heparin ELISA

BACKGROUND

Diagnosing heparin-induced thrombocytopenia (HIT) in patients with end-stage renal disease (ESRD) can be difficult, as they are frequently exposed to heparin and have multiple etiologies for thrombocytopenia.

OBJECTIVE

To correlate 4T scores, IgG heparin-platelet factor 4 (PF4-heparin) ELISA results, and serotonin release assay (SRA) results in patients with ESRD.

METHODS

We performed a retrospective review of patients with ESRD (creatinine clearance < 15 mL/min or on renal replacement therapy [RRT]) who underwent PF4-heparin ELISA testing from October 2015 to September 2019. True-positive PF4s required an intermediate to high 4T score (≥4), a positive SRA, and receipt of treatment for a HIT diagnosis. False-positive PF4s were defined as a positive PF4 with a negative SRA, low 4T score (<4), or lack of treatment for HIT. Indeterminant cases were classified on the basis of clinical assessment by the treating team (eg, hematology or vascular medicine).

RESULTS

Of 254 patients with ESRD (92% on RRT), 29 patients (11.4%) had a positive PF4. Eleven (37.9%) had a confirmed diagnosis of HIT: 10 patients who met all of the above criteria, and one who met the 4T criteria and was treated for HIT but did not have SRA testing due to high clinical suspicion and a positive PF4 test. False-positive PF4 values occurred in 8 patients (27.5%). Of 10 (34.5%) indeterminant cases of patients with a negative SRA but intermediate to high 4T and positive PF4, only 3 patients were treated for HIT, whereas the other 7 were judged not to have HIT as assessed by the treating clinician. In patients with an intermediate to high 4T score and PF4 optical density > 0.4 but negative SRA, who were not treated for HIT, there were no adverse outcomes documented such as new or progressive thrombosis.

CONCLUSION

In our ESRD population, 4T scores and PF4 testing were not predictive of a clinical diagnosis of HIT.

Treatment of Subarachnoid Hemorrhage-associated Delayed Cerebral Ischemia With Milrinone: A Review and Proposal

Delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage continues to be associated with high levels of morbidity and mortality. This complication had long been thought to occur secondary to severe cerebral vasospasm, but expert opinion now favors a multifactorial etiology, opening the possibility of new therapies. To date, no definitive treatment option for DCI has been recommended as standard of care, highlighting a need for further research into potential therapies. Milrinone has been identified as a promising therapeutic agent for DCI, possessing a mechanism of action for the reversal of cerebral vasospasm as well as potentially anti-inflammatory effects to treat the underlying etiology of DCI. Intra-arterial and intravenous administration of milrinone has been evaluated for the treatment of DCI in single-center case series and cohorts and appears safe and associated with improved clinical outcomes. Recent results have also brought attention to the potential outcome benefits of early, more aggressive dosing and titration of milrinone. Limitations exist within the available data, however, and questions remain about the generalizability of results across a broader spectrum of patients suffering from DCI. The development of a standardized protocol for milrinone use in DCI, specifically addressing areas requiring further clarification, is needed. Data generated from a standardized protocol may provide the impetus for a multicenter, randomized control trial. We review the current literature on milrinone for the treatment of DCI and propose a preliminary standardized protocol for further evaluation of both safety and efficacy of milrinone.

Virtual optimization of guideline-directed medical therapy in hospitalized patients with heart failure with reduced ejection fraction: the IMPLEMENT-HF pilot study

AIMS

Implementation of guideline-directed medical therapy (GDMT) for heart failure with reduced ejection fraction (HFrEF) remains incomplete. Non-cardiovascular hospitalization may present opportunities for GDMT optimization. We assessed the efficacy and durability of a virtual, multidisciplinary 'GDMT Team' on medical therapy prescription for HFrEF.

METHODS AND RESULTS

Consecutive hospitalizations in patients with HFrEF (ejection fraction ≤40%) were prospectively identified from 3 February to 1 March 2020 (usual care group) and 2 March to 28 August 2020 (intervention group). Patients with critical illness, de novo heart failure, and systolic blood pressure <90 mmHg in the preceeding 24 hs prior to enrollment were excluded. In the intervention group, a pharmacist-physician GDMT Team provided optimization suggestions to treating teams based on an evidence-based algorithm. The primary outcome was a GDMT optimization score, the sum of positive (+1 for new initiations or up-titrations) and negative therapeutic changes (-1 for discontinuations or down-titrations) at hospital discharge. Serious in-hospital safety events were assessed. Among 278 consecutive encounters with HFrEF, 118 met eligibility criteria; 29 (25%) received usual care and 89 (75%) received the GDMT Team intervention. Among usual care encounters, there were no changes in GDMT prescription during hospitalization. In the intervention group, β-blocker (72% to 88%; P = 0.01), angiotensin receptor-neprilysin inhibitor (6% to 17%; P = 0.03), mineralocorticoid receptor antagonist (16% to 29%; P = 0.05), and triple therapy (9% to 26%; P < 0.01) prescriptions increased during hospitalization. After adjustment for clinically relevant covariates, the GDMT Team was associated with an increase in GDMT optimization score (+0.58; 95% confidence interval +0.09 to +1.07; P = 0.02). There were no serious in-hospital adverse events.

CONCLUSIONS

Non-cardiovascular hospitalizations are a potentially safe and effective setting for GDMT optimization. A virtual GDMT Team was associated with improved heart failure therapeutic optimization. This implementation strategy warrants testing in a prospective randomized controlled trial.

Cardiac Myosin Activation for the Treatment of Systolic Heart Failure

ABSTRACT

Left ventricular systolic dysfunction is the hallmark pathology in heart failure with reduced ejection fraction. Increasing left ventricular contractility with beta-adrenergic receptor agonists, phosphodiesterase-3 inhibitors, or levosimendan has failed to improve clinical outcomes and, in some situations, increased the risk of sudden cardiac death. Beta-adrenergic receptor agonists and phosphodiesterase-3 inhibitors retain an important role in advanced heart failure. Thus, there remains an unmet need for safe and effective therapies to improve left ventricular systolic function. Two novel cardiac myotropes, omecamtiv mecarbil and danicamtiv, target cardiac myosin to increase left ventricular systolic performance. Neither omecamtiv mecarbil nor danicamtiv affects cardiomyocyte calcium handling, the proposed mechanism underlying the life-threatening arrhythmias associated with cardiac calcitropes and calcium sensitizers. Phase 2 clinical trials have demonstrated that these cardiac myosin activators prolong left ventricular systolic ejection time and promote left ventricular and atrial reverse remodeling. At higher plasma concentrations, these agents may be associated with myocardial ischemia and impaired diastolic function. An ongoing phase 3 clinical trial will estimate the clinical efficacy and safety of omecamtiv mecarbil. An additional study of these agents, which have minimal hemodynamic and renal effects, is warranted in patients with advanced heart failure refractory to guideline-directed neurohormonal blockers.