Nephrology considerations in the management of durable and temporary mechanical circulatory support

Durable and temporary mechanical circulatory support (MCS) use is growing for a range of cardiovascular indications. Kidney dysfunction is common in persons evaluated for or receiving durable or temporary MCS, and portends worse outcomes. This kidney dysfunction can be due to pre-existing kidney chronic kidney disease (CKD), acute kidney injury (AKI) related to acute cardiovascular disease necessitating MCS, AKI due to cardiac procedures, and due to acute and chronic MCS effects and complications. Durable MCS, with implantable continuous flow pumps, is used for long-term support in advanced HF refractory to guideline directed medical and device therapy, either permanently or as a bridge to heart transplantation. Temporary MCS-encompassing in this review intra-aortic balloon pumps (IABPs), axial flow pumps, centrifugal flow pumps, and venoarterial ECMO-is used for diverse situations: high risk percutaneous coronary interventions (PCI), acute decompensated heart failure (HF), cardiogenic shock, and resuscitation following cardiac arrest. The wide adoption of MCS makes it imperative to improve understanding of the effects of MCS on kidney health/function, and of kidney health/function on MCS outcomes. The complex structure and functions of the kidney, and the complex health states of individuals receiving MCS, makes investigations in this area challenging, and current knowledge is limited. Fortunately, the increasing nephrology toolbox of non-invasive kidney health/function assessments may enable development and testing of individualized management strategies and therapeutics in the future. We review technology, epidemiology, pathophysiology, clinical considerations, and future directions in MCS and nephrology.

Phenotyping of acute decompensated heart failure with preserved ejection fraction

ObjectiveThe pathophysiological heterogeneity of heart failure with preserved ejection fraction (HFpEF) makes the conventional ‘one-size-fits-all’ treatment approach difficult. We aimed to develop a stratification methodology to identify distinct subphenotypes of acute HFpEF using the latent class analysis.MethodsWe established a prospective, multicentre registry of acute decompensated HFpEF. Primary candidates for latent class analysis were patient data on hospital admission (160 features). The patient subset was categorised based on enrolment period into a derivation cohort (2016–2018; n=623) and a validation cohort (2019–2020; n=472). After excluding features with significant missingness and high degree of correlation, 83 features were finally included in the analysis.ResultsThe analysis subclassified patients (derivation cohort) into 4 groups: group 1 (n=215, 34.5%), characterised by arrythmia triggering (especially atrial fibrillation) and a lower comorbidity burden; group 2 (n=77, 12.4%), with substantially elevated blood pressure and worse classical HFpEF echocardiographic features; group 3 (n=149, 23.9%), with the highest level of GGT and total bilirubin and frequent previous hospitalisation for HF and group 4 (n=182, 29.2%), with infection-triggered HF hospitalisation, high C reactive protein and worse nutritional status. The primary end point—a composite of all-cause death and HF readmission—significantly differed between the groups (log-rank p<0.001). These findings were consistent in the validation cohort.ConclusionsThis study indicated the feasibility of clinical application of the latent class analysis in a highly heterogeneous cohort of patients with acute HFpEF. Patients can be divided into 4 phenotypes with distinct patient characteristics and clinical outcomes.Trial registration numberUMIN000021831.

IV Sodium Ferric Gluconate Complex in Patients Hospitalized Due to Acute Decompensated Heart Failure and Iron Deficiency

Background: Patients suffering from heart failure (HF) and iron deficiency (ID) have worse outcomes. Treatment with intra-venous (IV) ferric carboxymaltose has been shown to reduce HF rehospitalizations and to improve functional capacity and symptoms in patients with HF and reduced ejection fraction (HFrEF). However, IV ferric carboxymaltose is significantly more expensive than IV sodium ferric gluconate complex (SFGC) limiting its availability to most HF patients around the globe. Methods: A retrospective analysis comparing patients admitted to internal medicine or cardiology departments between January 2013 to December 2018 due to acute decompensated HF (ADHF) and treated with or without IV SFGC on top of standard medical therapy. Results: During the study period, a total of 1863 patients were hospitalized due to ADHF with either HFrEF or HF with preserved ejection fraction (HFpEF). Among them, 840 patients had laboratory evidence of iron deficiency (absolute or functional) and met the inclusion criteria. One hundred twenty-two of them (14.5%) were treated with IV SFGC during the index hospitalization. Patients treated with IV iron were more likely to have history of ischemic heart disease, atrial fibrillation, and chronic kidney disease. The rate of readmissions due to ADHF was similar between the groups at 30 days, 3 months, and 1 year. Conclusion: High risk patient hospitalized to ADHF and treated with IV SFGC showed comparable ADHF readmission rates, compared to those who did not receive iron supplementation.