The effect of eplerenone on the disease onset and progression of phospholamban cardiomyopathy in presymptomatic mutation carriers: results of the i-PHORECAST trial

Background

A pathogenic variant in the gene encoding phospholamban (PLN; p.Arg14del) may cause cardiomyopathy, the pathophysiologic hallmark of which is cardiac fibrosis that may cause malignant ventricular arrhythmias and severe heart failure. There is no evidence-based therapy to modify disease progression in presymptomatic pathogenic variant carriers. Eplerenone is a selective mineralocorticoid receptor antagonist with established antifibrotic properties, and may be a potentially interesting treatment in PLN p.Arg14del mutation carriers.

Purpose

To investigate if preventive therapy with eplerenone attenuates disease onset and progression in PLN cardiomyopathy.

Methods

84 presymptomatic PLN p.Arg14del mutation carriers (median age 39 [27–50] years, 44% males) were randomized 1:1 to receive eplerenone (50mg once daily) or no treatment, and endpoints were adjudicated in a blinded fashion (PROBE design). Baseline values were acquired including demographics, cardiac magnetic resonance imaging (CMR) parameters (ventricular volumes, systolic function, late gadolinium enhancement (LGE)), and electrocardiographic parameters (QRS voltages and ventricular ectopy per 24 hour). Subjects were re-evaluated every year and CMR was performed at baseline and after three years. The composite endpoint included LVEDV/RVEDV increase (>10%), LVEF/RVEF decrease (5%), newly developed LGE on CMR, increase in ventricular ectopy (>100% PVCs/24h if >1000 PVCs/24h), decrease in QRS voltage (>25%), non-sustained ventricular tachycardia, symptoms or arrhythmias necessitating treatment, and cardiovascular death.

Results

Two out of 84 subjects (2%) were lost to follow up. 49 out of 82 remaining subjects (60%) reached the composite end point, 25 (60%) in the control group, 24 (60%) in the treatment group (p=0.825). There was no significant difference between the groups when considering the individual end points, see Table 1. Baseline and follow up CMR was performed on 76 subjects, 39 in the control group, 37 in the treatment group. In total there were 10 (13%) cases of newly developed LGE, 6 (18%) in the control group, 4 (12%) in the treatment group (p=0.556), see Figure 1.

Conclusions

Eplerenone did not significantly attenuate disease onset and progression in presymptomatic PLN p.Arg14del mutation carriers. There was no significant difference in new incidence of LGE between the treatment and control groups.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was financially supported by the Netherlands Cardiovascular Research Initiative, an initiative supported by the Dutch Heart Foundation (The Hague, Netherlands).

Identification of IgG1 isotype phosphorylcholine antibodies for the treatment of inflammatory cardiovascular diseases

BACKGROUND

Phosphorylcholine (PC) is an important pro-inflammatory damage-associated molecular pattern. Previous data have shown that natural IgM anti-PC protects against cardiovascular disease. We aimed to develop a monoclonal PC IgG antibody with anti-inflammatory and anti-atherosclerotic properties.

METHODS

Using various techniques PC antibodies were validated and optimized. In vivo testing was performed in a femoral artery cuff model in ApoE3*Leiden mice. Safety studies are performed in rats and cynomolgus monkeys.

RESULTS

A chimeric anti-PC (PC-mAb(T15), consisting of a human IgG1 Fc and a mouse T15/E06 Fab) was produced, and this was shown to bind specifically to epitopes in human atherosclerotic tissues. The cuff model results in rapid induction of inflammatory genes and altered expression of genes associated with ER stress and choline metabolism in the lesions. Treatment with PC-mAb(T15) reduced accelerated atherosclerosis via reduced expression of endoplasmic reticulum stress markers and CCL2 production. Recombinant anti-PC Fab fragments were identified by phage display and cloned into fully human IgG1 backbones creating a human monoclonal IgG1 anti-PC (PC-mAbs) that specifically bind PC, apoptotic cells and oxLDL. Based on preventing macrophage oxLDL uptake and CCL2 production, four monoclonal PC-mAbs were selected, which to various extent reduced vascular inflammation and lesion development. Additional optimization and validation of two PC-mAb antibodies resulted in selection of PC-mAb X19-A05, which inhibited accelerated atherosclerosis. Clinical grade production of this antibody (ATH3G10) significantly attenuated vascular inflammation and accelerated atherosclerosis and was tolerated in safety studies in rats and cynomolgus monkeys.

CONCLUSIONS

Chimeric anti-PCs can prevent accelerated atherosclerosis by inhibiting vascular inflammation directly and through reduced macrophage oxLDL uptake resulting in decreased lesions. PC-mAb represents a novel strategy for cardiovascular disease prevention.

[Flank pain caused by a renal artery dissection]

BACKGROUND

A spontaneous renal artery dissection is a very rare diagnosis. The clinical presentation can vary and its course can be atypical. There are no guidelines available regarding treatment; however, the options are a conservative (medication) or interventional (radiological or surgical) approach.

CASE DESCRIPTION

A 45-year-old man presented to the emergency department with hypertensive urgency after earlier episodes of flank pain. The cause appeared to be a spontaneous bilateral renal artery dissection with infarction. After a multidisciplinary consultation, the decision was made to manage the patient conservatively since symptoms had subsided, blood pressure was acceptable and renal function remained stable. Eventually, kidney function restored to normal and CT images showed almost complete recovery of the previously damaged renal parenchyma.

CONCLUSION

This case demonstrates that in the event of renal artery dissection, a conservative medication policy may be a good option in clinically stable patients with non-deteriorating renal function. Timely recognition and adequate follow-up are important to prevent serious complications, such as renal ischaemia or renal infarction that could necessitate a nephrectomy.

An unexpected intriguing effect of Toll-like receptor regulator RP105 (CD180) on atherosclerosis formation with alterations on B-cell activation

OBJECTIVE

In atherosclerosis, Toll-like receptors (TLRs) are traditionally linked to effects on tissue macrophages or foam cells. RP105, a structural TLR4 homolog, is an important regulator of TLR signaling. The effects of RP105 on TLR signaling vary for different leukocyte subsets known to be involved in atherosclerosis, making it unique in its role of either suppressing (in myeloid cells) or enhancing (in B cells) TLR-regulated inflammation in different cell types. We aimed to identify a role of TLR accessory molecule RP105 on circulating cells in atherosclerotic plaque formation.

APPROACH AND RESULTS

Irradiated low density lipoprotein receptor deficient mice received RP105(-/-) or wild-type bone marrow. RP105(-/-) chimeras displayed a 57% reduced plaque burden. Interestingly, total and activated B-cell numbers were significantly reduced in RP105(-/-) chimeras. Activation of B1 B cells was unaltered, suggesting that RP105 deficiency only affected inflammatory B2 B cells. IgM levels were unaltered, but anti-oxidized low-density lipoprotein and anti-malondialdehyde-modified low-density lipoprotein IgG2c antibody levels were significantly lower in RP105(-/-) chimeras, confirming effects on B2 B cells rather than B1 B cells. Moreover, B-cell activating factor expression was reduced in spleens of RP105(-/-) chimeras.

CONCLUSIONS

RP105 deficiency on circulating cells results in an intriguing unexpected TLR-associated mechanisms that decrease atherosclerotic lesion formation with alterations on proinflammatory B2 B cells.

Annexin A5 prevents post-interventional accelerated atherosclerosis development in a dose-dependent fashion in mice

BACKGROUND

Activated cells in atherosclerotic lesions expose phosphatidylserine (PS) on their surface. Annexin A5 (AnxA5) binds to PS and is used for imaging atherosclerotic lesions. Recently, AnxA5 was shown to inhibit vascular inflammatory processes after vein grafting. Here, we report a therapeutic role for AnxA5 in post-interventional vascular remodeling in a mouse model mimicking percutaneous coronary intervention (PCI).

METHODS AND RESULTS

Associations between the rs4833229 (OR = 1.29 (CI 95%), p(allelic) = 0.011) and rs6830321 (OR = 1.35 (CI 95%), p(allelic) = 0.003) SNPs in the AnxA5 gene and increased restenosis-risk in patients undergoing PCI were found in the GENDER study. To evaluate AnxA5 effects on post-interventional vascular remodeling and accelerated atherosclerosis development in vivo, hypercholesterolemic ApoE(-/-) mice underwent femoral arterial cuff placement to induce intimal thickening. Dose-dependent effects were investigated after 3 days (effects on inflammation and leukocyte recruitment) or 14 days (effects on remodeling) after cuff placement. Systemically administered AnxA5 in doses of 0.1, 0.3 and 1.0mg/kg compared to vehicle reduced early leukocyte and macrophage adherence up to 48.3% (p = 0.001) and diminished atherosclerosis development by 71.2% (p = 0.012) with a reduction in macrophage/foam cell presence. Moreover, it reduced the expression of the endoplasmic reticulum stress marker GRP78/BiP, indicating lower inflammatory activity of the cells present.

CONCLUSIONS

AnxA5 SNPs could serve as markers for restenosis after PCI and AnxA5 therapeutically prevents vascular remodeling in a dose-dependent fashion, together indicating clinical potential for AnxA5 against post-interventional remodeling.