His-bundle pacing: impact of social media

The San Francisco based social networking service Twitter was founded in 2006 as a mobile social media platform designed to instantaneously publish bite-sized text and media clips or ‘tweets’. The name Twitter was in part chosen for how perfectly the dictionary definition described the product’s initial intent—‘a short burst of inconsequential information’ and ‘a chirp from birds’. The concept of birds chirping was particularly meaningful according to co-founder and CEO Jack Dorsey because it, ‘sounds meaningless to us, but the meaning is applied by other birds’.1 Over time, the utility and purpose of twitter matured, gaining traction in politics, academia, business, and news broadcasting due to its ability to disseminate information to large audience in real time. Several recent publications have described the explosive growth of twitter use by physicians attending scientific meetings and the potential impact of rapid distribution of practice-changing information to a global audience.2–4 These tweets were initially met with staunch opposition citing copyright issues5; however, analyses of meeting tweets has found that content was mostly informative, original, and contributed by physicians.3,6 Most medical societies have not only reversed their opposition to Twitter but embraced and encouraged ‘tweeting the meeting’. Instantaneous broadcasting of information via social media platforms such as Twitter, while not without controversy, may improve medical education, speeds the spread of information and surely adds appeal to scientific conferences that have suffered recent declines in attendance. Due to its ease of use and accessibility, Twitter is a particularly powerful platform for the discussion of orphaned and avant-garde ideas, which may not otherwise reach a wider community. One such idea is His-bundle pacing (HBP), a concept which was born in the late 1960’s and almost extinguished on several occasions were it not for the vocal backing of its champions before appearing in 2018 clinical practice guidelines for the management of bradycardia.7 His-bundle pacing, an unique technique for pacing in the bundle of His to recreate native ventricular depolarization, began as a fringe movement in electrophysiology, dating back to Narula, Sherlag, and Semet’s description of HBP with electrode catheters in 1969.8 It would not be until 30 years later that permanent HBP was demonstrated in humans by Deshmukh et al.9 in a series of 12 patients. Deshmukh’s work showed considerable promise for this novel pacing technique regarding feasibility and short-term reliability, achieving 66% procedural success in this first report. He concluded that further studies with better lead design and shaped or steerable lead delivery systems could determine whether permanent HBP offers physiologic benefit over contemporary pacing approaches. However, at the time of its publication the concept of multisite pacing to achieve interventricular synchrony and reduce the deleterious effects of right ventricular (RV) pacing was already gaining considerable traction, industry interest, and research and development dollars.10–12 Several multicentre randomized control trials of cardiac resynchronization therapy (CRT)13–17 relegated HBP to the cardiac pacing sidelines as biventricular pacing demonstrated a reduction in mortality or heart failure event rates compared with RV lead placement alone. The field of electrophysiology saw an explosion of novel device and lead delivery systems development for biventricular pacing for cardiac synchronization, a concept that by first principle is inherent to HBP. Between publication of Deshmukh’s group’s report in 2000 and the following decade, a handful of case reports and small series were published on the clinical applications of HBP.18–22 The investigators of these few series represented tiny factions within the electrophysiology community. By the mid 2010s, and despite the established biventricular pacing as the standard for physiologic pacing, the number of HBP implantations had grown, and small prospective and retrospective analyses started to appear in the literature.23 These papers chronicled the use of HBP for resynchronization,24–26 post-atrioventricular (AV) node ablation27,28 and AV block,29 improvement of haemodynamic parameters, and assessment of medium-term outcomes.30 Vijayaraman et al. have since demonstrated long-term lead performance in HBP,31 long-term electrophysiological and echocardiographic implications,32 safety and feasibility of HBP in complete AV block,27 and clinical outcomes compared with RV pacing33 and have published several HBP implantation tutorials.34–36 In 2015, the phrase ‘Don’t diss the His’, playfully coined as a Halloween theme by the electrophysiology advanced practitioners at the Geisinger Heart Institute was used as the main hashtag (a form of repository for tweets and media posts) for the HBP enthusiasts (#dontdisthehis).37 This is an exploratory historical observational report aimed to better understand the contemporaneous and possibly concerted rise in HBP and its presence on social media. The Twitter hashtag #dontdisthehis was registered with Symplur Signals, a healthcare social media analytics company. Both live and historic data on the use of #dontdisthehis was curated and analysed from all public postings between January 2015 and October 2018. This data was used to determine the number of users, tweets, and impressions (tweets × number of followers) over time as well as to identify high-impact tweets. Generalized United States sales data of the 3830 lead was obtained courtesy of Medtronic. The once logarithmic, now exponential growth of this movement is depicted by the Twitter analytics data in Figure 1A and B. Surges in hashtag utilization can likely be correlated with the annual scientific sessions of American College of Cardiology in March, Heart Rhythm Society in May, and the Physiology of Pacing Symposium in November. The cumulative rise in Twitter impressions (A) and Twitter users (B) utilizing the hashtag #dontdisthehis between January 2015 and December 2018 (data courtesy of Symplur, a healthcare social media analytics company). (C) Exponential rise in 3830 sales over the same timeframe (data courtesy of Medtronic). The social media posts and networking by the HBP enthusiasts may have allowed the rapid spread of this concept of physiologic pacing, who were able to initiate a collaborative movement reporting to the Twittersphere not only their published works but also their day in, day out successes, stumbles, and breakthroughs in the pacing laboratory (Figures2–4). The movement appears to have slowly gained traction and garnered interest in the larger electrophysiology community reflected in an increased twitter communications, increases in HBP sessions in major meetings (Heart Rhythm Society, American College of Cardiology, American Heart Association), development of dedicated stand-alone symposiums on HBP (physician organized and industry supported), and increased adoption of HBP in daily practice. Perhaps the most remarkable aspect of the burgeoning of HBP is that it occurred despite the absence of incentive from payers, no research initiatives from industry and strong competition from innovation in CRT. Example of impactful tweets utilizing #dontdisthehis. As of 31 December 2018, the above tweets have made 104 252 (A), 125 578 (B), 136 654 (C), and 123 951 (D) impressions. Educational tweets within the His-bundle pacing community are shown in panels A and B. Tweet on His-bundle pacing troubleshooting. His-bundle pacing has primarily been performed in the last decade utilizing the SelectSecure™ (Model number 3830, Medtronic Inc., Minneapolis, MN, USA) pacing lead and SelectSite™ delivery systems (C315His and C304, Medtronic Inc.), although a few investigators have attempted HBP using the traditional pacing leads. While the 3830 lead was not specifically designed for HBP, this lead was primarily implanted by paediatric electrophysiologists (preferred for their 4.1-Fr lead diameter) and HBP implanters. Food and Drug Administration (FDA) originally approved the lead in 2005, and then granted it specific FDA labelling for HBP in 2018. The growth of HBP implantations can be indirectly tracked through the uptake in 3830 lead utilizations38 and device sales (Figure 1C). Social media has led to disruptions in the traditional review process of scientific journals. While anonymous third person review process has its strengths and weaknesses, social media has changed how science and scientific publications are reviewed. Remarkable discussions and critical scrutiny of major landmark trials such as VEST and ORBITA immediately followed their publications. Similar profound discussions were abundant in the social media following the presentation of the CABANA trial. Social media now pits the wisdom of a few peer reviewers against the wisdom of the crowds and is likely to result in changes to the traditional peer review process in the future. In November of 2018, the clinical practice guidelines for the management of bradycardia and AV block included a Class IIa recommendation for HBP over RV pacing in patients with an ejection fraction between 36% and 50% who are expected to require ventricular pacing more than 40% of the time. His-bundle pacing also received a Class IIb recommendation for consideration compared with RV pacing in patients with AV block at the level of the AV node.7 We propose that Twitter likely had a considerable impact on the spread of HBP and its integration into mainstream electrophysiology. The platform has allowed physicians to regain some steering power over industry in medical innovation and has expanded from a digital diary of ‘inconsequential information’ to a global microphone for innovators and mavericks in the medical field. The rise of HBP in the Twitter-sphere likely led to increased adopters in clinical practice, better investments into technology by the industry and renewed interest globally in physiologic pacing. The association of the rise in HBP and its growth on Twitter shows how social media can disseminate information rapidly and galvanize physicians in pursuing therapies that require minimal industry support, yet directly benefit patient care. Because our report is retrospective and single-armed, we cannot make causal claims. That said, there were no controlled trials of the printing press—and no one doubts its causal impact on progress. While we do not know whether HBP would have grown without Twitter’s global reach, we do have a supportive counterfactual: the far lower use of the 3830 lead in the time period immediately before the surge in the #dontdisthehis hashtag—a time after published reports of HBP and when a lead and delivery system were available. It is also true that we cannot entirely disprove reverse causation: that the rise in HBP and several recent scientific publications led to increased awareness in the social media. Another important factor with the use of Twitter is publication bias of cases posted online. When successful, HBP produces beautiful images; it’s likely, therefore, that online posts most often represent the best-case scenarios. Twitter posts less frequently feature the challenges of HBP, such as raising thresholds and lower generator longevity and higher rates of lead revisions. Publication bias, though, is hardly unique to social media. His-bundle pacing's recent uptake in electrophysiology community has been closely mirrored and likely amplified by its presence on Twitter. The advent of social media has revolutionized the circulation and vetting process of emerging technologies and has generated much needed peer to peer discussion. Conflict of interest: G.D.—speaker, consultant, research (Medtronic), consultant (Biotronik); P.A.F.---research support (SJM), intellectual property rights (Aegis Medical, NeoChord, Preventice, Sorin, AliveCor, Champion Medical, Apervita, Reemo), speaker or consultant (Medtronic, Leadex, Boston Scientific), equity (MediCool); P.V.—honoraria, consultant, research, fellowship support (Medtronic), consultant (Boston Scientific, Abbott, Biotronik, Merritt Medical), patent pending for His-bundle pacing delivery tool. D.B. and J.M. declared no conflict of interest.