Peter Johannes Kennel

Despite advances in our understanding of myocardial recovery among left ventricular assist device (LVAD) patients, with 10–30% of patients achieving substantial myocardial improvement, the rates of LVAD support cessation remain extremely low (1–2%). These numbers are in stark contrast to clinical trial data where successful LVAD cessation is reported in up to 47% of patients. The majority of LVAD programs lack structured recovery programs and targeted protocols, likely underscoring the heterogeneity that exists among LVAD patients with myocardial recovery. This perspective summarizes the current medical and surgical challenges with respect to 1) identifying the appropriate candidates for LVAD cessation; 2) methods to wean LVAD support; 3) reviewing surgical techniques for cessation of current generation HeartMate 3 LVAD; and 4) approaching shared decision making for LVAD cessation between patients and providers given the uncertainties that remain in the field.

Heart failure (HF) is characterized by global alterations in myocardial DNA methylation, yet little is known about the epigenetic regulation of the noncoding genome and potential reversibility of DNA methylation with left ventricular assist device (LVAD) therapy. Genome-wide mapping of myocardial DNA methylation in 36 patients with HF at LVAD implantation, 8 patients at LVAD explantation, and 7 nonfailing (NF) donors using a high-density bead array platform identified 2,079 differentially methylated positions (DMPs) in ischemic cardiomyopathy (ICM) and 261 DMPs in nonischemic cardiomyopathy (NICM). LVAD support resulted in normalization of 3.2% of HF-associated DMPs. Methylation-expression correlation analysis yielded several protein-coding genes that are hypomethylated and upregulated ( HTRA1 , FBXO16 , EFCAB13 , and AKAP13 ) or hypermethylated and downregulated ( TBX3 ) in HF. A potentially novel cardiac-specific super-enhancer long noncoding RNA (lncRNA) ( LINC00881 ) is hypermethylated and downregulated in human HF. LINC00881 is an upstream regulator of sarcomere and calcium channel gene expression including MYH6 , CACNA1C , and RYR2 . LINC00881 knockdown reduces peak calcium amplitude in the beating human induced pluripotent stem cell–derived cardiomyocytes (hiPSC-CMs). These data suggest that HF-associated changes in myocardial DNA methylation within coding and noncoding genomes are minimally reversible with mechanical unloading. Epigenetic reprogramming strategies may be necessary to achieve sustained clinical recovery from heart failure.

Aims We aimed to detail the early clinical experience with pVAD 5.5 at a large academic medical centre. Impella® 5.5 (Abiomed) is a temporary peripherally inserted left ventricular assist device (pVAD) used for the treatment of cardiogenic shock (CS). This system has several modifications aimed at improving deliverability and durability over the pVAD 5.0 system, but real-world experience with this device remains limited. Methods and results We collected clinical and outcome data on all patients supported with pVAD 5.5 at our centre between February and December 2020, including procedural and device-related complications. Fourteen patients with pVAD 5.5 were included. Aetiology of CS was acute myocardial infarction (n = 6), decompensated heart failure (n = 6), suspected myocarditis (n = 1), and post-cardiotomy CS (n = 1). Four patients received pVAD 5.5 after being on inotropes alone, two were escalated from intra-aortic balloon pump, two were escalated from pVAD CP, and six patients were transitioned to pVAD 5.5 from extracorporeal membrane oxygenation. Median duration of pVAD 5.5 support was 12 (interquartile range 7, 25) days. Complications included axillary insertion site haematoma (n = 3), acute kidney injury (n = 3), severe thrombocytopenia (n = 1), and stroke (n = 1). No valve injury or limb complications occurred. Survival to device explant for recovery or transition to another therapy was 11/14 (79%) patients. Conclusions In this early experience of the pVAD 5.5, procedural and device-related complications were observed but were manageable, and overall survival was high in this critically ill cohort, particularly when the device was used as a bridge to other therapies.

Aims: Allograft rejection following heart transplantation (HTx) is a serious complication even in the era of modern immunosuppressive regimens and causes up to a third of early deaths after HTx. Allograft rejection is mediated by a cascade of immune mechanisms leading to acute cellular rejection (ACR) and/or antibody-mediated rejection (AMR). The gold standard for monitoring allograft rejection is invasive endomyocardial biopsy that exposes patients to complications. Little is known about the potential of circulating miRNAs as biomarkers to detect cardiac allograft rejection. We here present a systematic analysis of circulating miRNAs as biomarkers and predictors for allograft rejection after HTx using next-generation small RNA sequencing. Methods and results: We used next-generation small RNA sequencing to investigate circulating miRNAs among HTx recipients (10 healthy controls, 10 heart failure patients, 13 ACR, and 10 AMR). MiRNA profiling was performed at different time points before, during, and after resolution of the rejection episode. We found three miRNAs with significantly increased serum levels in patients with biopsy-proven cardiac rejection when compared with patients without rejection: hsa-miR-139-5p, hsa-miR-151a-5p, and hsa-miR-186-5p. We identified miRNAs that may serve as potential predictors for the subsequent development of ACR: hsa-miR-29c-3p (ACR) and hsa-miR-486-5p (AMR). Overall, hsa-miR-486-5p was most strongly associated with acute rejection episodes. Conclusions: Monitoring cardiac allograft rejection using circulating miRNAs might represent an alternative strategy to invasive endomyocardial biopsy.

Presentation of life-threatening arrhythmias concomitantly with a new-onset non-ischaemic cardiomyopathy raises concern for an inflammatory cardiomyopathy such as cardiac sarcoidosis or cardiac manifestations of connective tissue disease. Comprehensive workup for specific aetiologies may be unrevealing except for signs of myocardial inflammation identified on cardiac positron emission tomography (PET). Here, we present five cases of such subjects and their clinical course. We collected clinical, imaging, pathological, and follow-up data of five subjects presenting with arrhythmias and unexplained new-onset cardiomyopathy. Mean age was 56.2 ± 5.8 years. Three subjects presented with ventricular tachycardia and two with atrial arrhythmias. Echocardiography showed a mean left ventricular ejection fraction of 37 ± 9%_. Significant coronary artery disease was ruled out in all cases as the cause of the cardiomyopathy. All patients underwent cardiac magnetic resonance imaging (MRI) and PET scan at presentation and follow-up. In all patients, cardiac MRI revealed hyperenhancement in epicardial and mid-myocardial pattern in a non-coronary distribution, while PET scan revealed fluorodeoxyglucose (FDG) mismatch defects in multiple foci in a non-coronary distribution. Right ventricular biopsy was obtained in all patients and revealed interstitial fibrosis and cardiomyocyte hypertrophy. On median follow-up of 210 days, all subjects had improvement in both heart failure symptoms and arrhythmias and repeat PET in four out of five patients showed decreased inflammation. A high level of suspicion for inflammatory cardiomyopathy is needed in patients presenting with new unexplained cardiomyopathy and arrhythmias. A cardiac FDG-PET should be considered for diagnosis if cardiac inflammation is in the differential. This can inform further decisions regarding targeted immunomodulation therapy that may be helpful in this cohort.