P1021Comparative efficacy of microfidelity technology vs standard ablation for atrioventricular nodal ablation

Background

Microfidelity Cateter Technology has proven efficacy in ablating atrial arrhythmias in multiple pilot studies. Closely spaced radial microelectrodes render a focused near-field electrogram. Case series suggest that this catheter design facilitates accurate ablations with fewer radiofrequency (RF) lesions. Atrioventricular junction (AVJ) ablation is regarded as a straightforward procedure, but case records show wide variance in procedure times and number of RF lesions required.

Methods

Twenty-four patients scheduled for AVJ ablation were randomized to treatment with either the Microfidelity technology or standard 8mm/8 French ablation catheter. Both groups located the AVJ by fluoroscopic landmarks and His electrograms, and the MiFi group used electroanatomical mapping to create the location of his electrograms. The primary endpoints were development of Junctional Rhythm (JR) or Complete Heart Block (CHB), and time from first RF lesion until rhythm change. Secondary endpoints included number of RF applications.

Results

Patients were randomized one-to-one to the MiFi arm or standard ablation arm. JR or CHB was achieved in all patients. Time from first RF lesion until JR/CHB was: (Median/IQR) 325 sec/250–1270 sec. vs 287 sec/101–406 sec. Number of RF applications was 5/3–15 applications vs 4.5/1–5 applications. Total procedure time in the lab was 134 min/73.5–172.5 min vs 58 min/52–146 min.

Microfidelity Technology vs Standard

Conclusion

Analysis suggests that the MiFi catheter is efficacious in ablating the AVJ, but requires greater RF duration and number of lesions, with wider case-by-case variability to achieve JR or CHB. Microfidelity technology and electroanatomical mapping did not result in faster time to completion than using fluoroscopic landmarks and His electrograms alone. Preoperative choice of sheath for catheter stability and contact may also play a role in a more efficient timely successful ablation of the AV node.

Acknowledgement/Funding

Boston Scientific

P1675Evolution of lactate dehydrogenase levels in patients with HeartMate II, HeartWare and HeartMate 3 left ventricular assist devices during first-year follow-up

Background

Lactate dehydrogenase (LDH) is considered as a biomarker of thrombotic events in patients receiving a left ventricular assist device (LVAD).

Purpose

This study aimed to investigate the evolution of LDH levels over time between patients supported with a HeartMate II (HMII), HeartMate 3 (HM3) or HeartWare (HVAD) LVAD during their first-year post implantation.

Methods

We analyzed in this multi-center retrospective study, all patients with HMII, HM3 and HVAD LVAD implanted between December 2006 and April 2017. Patients were classified into three groups based on their device type. Loess splines over time were used to depict the repeated measurements of LDH.

Results

In total, 134 patients received an LVAD (77% male, mean age 55 [46–61]), of whom 64 (48%) were HMII, 22 (16%) HM3 and 48 (36%) were HVAD. Loess splines over time indicate that there could be a considerable difference between evolution of LDH (Figure). During the first-year follow-up, 3 (5%) patients had a confirmed and 10 (16%) patients had a suspected pump thrombosis in the HMII group. For the HVAD, there were 6 (13%) patients with confirmed thrombosis and 1 (2%) case of suspected thrombosis, whereas none of the patients in the HM3 group experienced a suspected or confirmed pump thrombosis (p=0.01). The 1-year overall survival rate for HM II, HM3 and HVAD was 84%, 86% and 72% respectively (p=0.311). The overall stroke-free rate at one year was: 89%, 77% and 91% for HMII, HVAD and HM3 respectively (p=0.15).

Means of observed LDH values over time

Conclusion

During the first-year post LVAD implantation, there appear to be different evolutions of LDH levels over time in HMII device patients compared to HVAD or HM3 device patients. Given differences in baseline hemolysis levels between devices, currently used LDH thresholds for detection of impending pump thrombosis may be less sensitive and thus thresholds may be device specific.

Efficacy and safety of brodalumab in patients with psoriasis who had inadequate responses to ustekinumab: subgroup analysis of two randomized phase III trials

BACKGROUND

Brodalumab, a fully human anti-interleukin-17 receptor A monoclonal antibody, has demonstrated superior efficacy and safety over ustekinumab as induction therapy for moderate-to-severe psoriasis.

OBJECTIVES

To evaluate the efficacy and safety of brodalumab through week 52 in patients who had inadequate responses to ustekinumab.

METHODS

A subgroup analysis of the phase III AMAGINE-2/-3 double-blind randomized controlled trials was performed. Participants were aged 18-75 years and had a Psoriasis Area and Severity Index (PASI) ≥ 12, static Physician's Global Assessment score ≥ 3 and involvement of ≥ 10% body surface area. The studies were registered at ClinicalTrials.gov: AMAGINE-2, NCT01708603; AMAGINE-3, NCT01708629.

RESULTS

At baseline, patients with or without prior biologic experience who had an adequate response at week 16 on ustekinumab or brodalumab had lower rates of involved body surface area, PASI, prior biologic use, psoriatic arthritis and body mass index than patients who experienced inadequate response at or after week 16. Among patients who experienced inadequate response to ustekinumab, those rescued with brodalumab had PASI ≥ 75%, ≥ 90% and 100% improvement response rates of 72·6%, 58·1% and 36·3%, respectively, at week 52 compared with 61·7%, 25·5% and 5·4%, respectively, in patients who continued ustekinumab. Exposure-adjusted rates of treatment-emergent adverse events were similar among patients rescued with brodalumab (377·3 adverse events per 100 patient-years) and those who remained on ustekinumab (389·9 adverse events per 100 patient-years).

CONCLUSIONS

Among patients who experienced inadequate responses to ustekinumab, rescue with brodalumab improved skin clearance outcomes compared with continuing ustekinumab.

Improvement in itch and other psoriasis symptoms with brodalumab in phase 3 randomized controlled trials

BACKGROUND

Patients with psoriasis have lesional symptoms, including itch, which can reduce quality of life. The efficacy and safety of brodalumab, an interleukin-17 receptor A antagonist, in treating moderate-to-severe psoriasis have been reported in three randomized, controlled, phase 3 trials (AMAGINE-1/-2/-3).

OBJECTIVE

The effect of brodalumab on lesional symptoms was assessed using the psoriasis symptom inventory (PSI), a validated patient-reported instrument.

METHODS

Patients were randomized to receive brodalumab (140 or 210 mg every 2 weeks [Q2W]), placebo (AMAGINE-1/-2/-3), or ustekinumab (AMAGINE-2/-3) during a 12-week induction phase, followed by a maintenance phase through week 52. Patients electronically rated the severity of PSI items (itch, burning, stinging, pain, redness, scaling, cracking and flaking) during the previous 24 h on a scale of 0 (not at all severe) to 4 (very severe). At each visit, the PSI total score responder status was assessed, with responders defined as having an average weekly total inventory score ≤8 with no item score >1 at week 12.

RESULTS

Across AMAGINE-1/-2/-3, brodalumab was associated with improvements in PSI total scores and itch scores vs. placebo from week 2 through week 12 (P < 0.001 in both domains). In AMAGINE-2/-3, brodalumab 210 mg Q2W demonstrated faster onset of PSI total score and itch responses (week 2, 22.1% and 36.4%, respectively) vs. ustekinumab (week 2, 6.9% and 17.1%, respectively) and was associated with improved itch responses vs. ustekinumab after 52 weeks of constant treatment.

CONCLUSION

Brodalumab demonstrated rapid, robust improvements in symptoms assessed by the PSI, including itch, vs. placebo and ustekinumab.

Blue Light Differentially Modulates Cell Survival and Growth

Previous studies have reported that blue light (400–500 nm) inhibits cell mitochondrial activity. We investigated the hypothesis that cells with high energy consumption are most susceptible to blue-light-induced mitochondrial inhibition. We estimated cell energy consumption by population doubling time, and cell survival and growth by succinate dehydrogenase (SDH) activity. Six cell types were exposed to 5 or 60 J/cm2 of blue light from quartz-tungsten-halogen (QTH), plasma-arc (PAC), or argon laser sources in monolayer culture. Post-light SDH activity correlated positively with population doubling time (R2 = 0.91 for PAC, 0.76 for QTH, 0.68 for laser); SDH activity increased for cell types with the longest doubling times and was suppressed for cell types with shorter doubling times. Thus, light-induced exposure differentially affects SDH activity, cell survival, and growth, depending on cell energy consumption. Blue light may be useful as a therapeutic modulator of cell growth and survival.