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Fulltext Performance of a novel left ventricular lead with short bipolar spacing for cardiac resynchronization therapy: primary results of the Attain Performa quadripolar left ventricular lead study

Crossley GH, Biffi M, Johnson B, Lin A, Gras D, Hussin A, et al.

Heart Rhythm, 2015 Apr;12(4):751-8.
PMID: 25533587 DOI: 10.1016/j.hrthm.2014.12.019

The Medtronic Attain Performa quadripolar leads provide 16 pacing vectors with steroid on every electrode. This includes a short bipolar configuration between the middle 2 electrodes.
Fulltext Long-term performance of a transcatheter pacing system: 12-Month results from the Micra Transcatheter Pacing Study

Duray GZ, Ritter P, El-Chami M, Narasimhan C, Omar R, Tolosana JM, et al.

Heart Rhythm, 2017 05;14(5):702-709.
PMID: 28192207 DOI: 10.1016/j.hrthm.2017.01.035

BACKGROUND: Early performance of the Micra transcatheter pacemaker from the global clinical trial reported a 99.2% implant success rate, low and stable pacing capture thresholds, and a low (4.0%) rate of major complications up to 6 months.
OBJECTIVE: The purpose of this report was to describe the prespecified long-term safety objective of Micra at 12 months and electrical performance through 24 months.
METHODS: The Micra Transcatheter Pacing Study was a prospective single-arm study designed to assess the safety and efficacy of the Micra VVIR leadless/intracardiac pacemaker. Enrolled patients met class I or II guideline recommendations for de novo ventricular pacing. The long-term safety objective was freedom from a system- or procedure-related major complication at 12 months. A predefined historical control group of 2667 patients with transvenous pacemakers was used to compare major complication rates.
RESULTS: The long-term safety objective was achieved with a freedom from major complication rate of 96.0% at 12 months (95% confidence interval 94.2%-97.2%; P < .0001 vs performance goal). The risk of major complications for patients with Micra (N = 726) was 48% lower than that for patients with transvenous systems through 12 months postimplant (hazard ratio 0.52; 95% confidence interval 0.35-0.77; P = .001). Across subgroups of age, sex, and comorbidities, Micra reduced the risk of major complications compared to transvenous systems. Electrical performance was excellent through 24 months, with a projected battery longevity of 12.1 years.
CONCLUSION: Long-term performance of the Micra transcatheter pacemaker remains consistent with previously reported data. Few patients experienced major complications through 12 months of follow-up, and all patient subgroups benefited as compared to transvenous pacemaker historical control group.
Fulltext Long-term outcomes in leadless Micra transcatheter pacemakers with elevated thresholds at implantation: Results from the Micra Transcatheter Pacing System Global Clinical Trial

Piccini JP, Stromberg K, Jackson KP, Laager V, Duray GZ, El-Chami M, et al.

Heart Rhythm, 2017 05;14(5):685-691.
PMID: 28111349 DOI: 10.1016/j.hrthm.2017.01.026

BACKGROUND: Device repositioning during Micra leadless pacemaker implantation may be required to achieve optimal pacing thresholds.
OBJECTIVE: The purpose of this study was to describe the natural history of acute elevated Micra vs traditional transvenous lead thresholds.
METHODS: Micra study VVI patients with threshold data (at 0.24 ms) at implant (n = 711) were compared with Capture study patients with de novo transvenous leads at 0.4 ms (n = 538). In both cohorts, high thresholds were defined as >1.0 V and very high as >1.5 V. Change in pacing threshold (0-6 months) with high (1.0 to ≤1.5 V) or very high (>1.5 V) thresholds were compared using the Wilcoxon signed-rank test.
RESULTS: Of the 711 Micra patients, 83 (11.7%) had an implant threshold of >1.0 V at 0.24 ms. Of the 538 Capture patients, 50 (9.3%) had an implant threshold of >1.0 V at 0.40 ms. There were no significant differences in patient characteristics between those with and without an implant threshold of >1.0 V, with the exception of left ventricular ejection fraction in the Capture cohort (high vs low thresholds, 53% vs 58%; P = .011). Patients with an implant threshold of >1.0 V decreased significantly (P < .001) in both cohorts. Micra patients with high and very high thresholds decreased significantly (P < .01) by 1 month, with 87% and 85% having 6-month thresholds lower than the implant value. However, when the capture threshold at implant was >2 V, only 18.2% had a threshold of ≤1 V at 6 months and 45.5% had a capture threshold of >2 V.
CONCLUSIONS: Pacing thresholds in most Micra patients with elevated thresholds decrease after implant. Micra device repositioning may not be necessary if the pacing threshold is ≤2 V.
Fulltext Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1

Klionsky DJ, Abdel-Aziz AK, Abdelfatah S, Abdellatif M, Abdoli A, Abel S, et al.

Autophagy, 2021 Jan;17(1):1-382.
PMID: 33634751 DOI: 10.1080/15548627.2020.1797280

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field.