The future of interventional cardiology

Before speculating on where interventional cardiology is heading to, it may be helpful to reflect on its true origin. For many of you, early or halfway through your career, interventional cardiology may seem a well-established and mature subspecialty. For you it has always been a major component within the field of cardiology. However, for those of us who were already here before interventional cardiology even existed and have witnessed its birth, child- hood, and adolescence, interventional cardiology is just a moment in time. Currently, we feel pretty confident that we are treating coronary artery disease adequately with prompt interventions for the management of acute myocardial infarctions and chronic conditions with sophisticated instruments, excellent results, and satisfied patients. We also felt confident when we had balloons only. Yes, there were many failures back then, but interventional cardiology would have never flourished if it was not for optimism. I keep a video recording of our colleague and father of interventional cardiology, Andreas Gruentzig, MD, just before his untimely death. He said that balloons were the solution for many conditions, but also that we needed much more than that if we wanted to solve the obvious problems of coronary artery obstruction. The next decade would witness innovation attempts, some of them ranging from excellence to eccentricity1 All types of lasers to burn, seal, selectively ablate only abnormal tissue; hot-tip catheters; cold freezing instruments; cutters and scrapers; and finally scaffolds that we would call stents. Peripheral artery interventions followed a similar path. Although these came before coronary interventions, these techniques evolved slower. The ability to perform minimally invasive procedures for structural heart disease lagged behind. In the late 1980s, Alain Cribier, MD presented the idea of balloon dilatation of the aortic valve at our Emory courses2 We tried it for some time. Fifteen years later he implanted the first transcatheter aortic valve. It takes a while before ideas come to life. Back in 1990, we predicted that restenosis would be conquered by a device to hold the artery open combined with locally-delivered anti-proliferative agents. At first, we tried radiation, but cell-cycle inhibition stents eventually became the standard of care.

There were many difficulties then. Some were overcome, and some carried their own issues. What are the problems we face today, and how will they be approached in the future? The most successful coronary intervention occurs in the setting of acute myocardial infarctions. Making this technology widely available is still challenging because even though it can be done, myocardial salvage has not been completely solved. Innovations such as left ventricular support combined with reperfusion while paying special attention to microcirculation and its response to reperfusion deserve further research. We still do not know what to do with non-culprit but narrowed coronary arteries in the setting of myocardial infarctions.

Techniques for opening chronic total occlusions and bifurcation lesions have progressed, but we still don’t have dedicated devices for bifurcations, and reopening chronic total occlusions through the true lumen requires innovations that are still to come. Although percutaneous aortic valve implantation has evolved faster than any of us would have anticipated, long-term results are still awaited, and mitral and tricuspid valve replacements are still in their infancy. Peripheral endovascular therapies seem spectacular, but endo-leaks and aneurysm expansion have not been completely solved yet.

Also, the lines between disciplines are blurry. Stroke intervention is the most dramatic advance in the field. Will clot retrieval from cerebral arteries remain the scope of neurologists only? There are not enough of them, and cardiologists are entering their specialty. On the other hand, interventional cardiology will not be the sole domain of cardiologists. A recent approach to the excessive stroke rate from carotid stenting has resulted in the direct surgical exposure of the artery with stent implantation combined with reverse carotid blood flow enabled by a shunt via the femoral vein. This kind of innovations combine surgical skills and training together with catheter skills. An interdisciplinary collaboration that can be perfected in some healthcare systems. A trial sponsored by the National Heart, Lung, and Blood Institute (NHLBI) is now underway to assess the validity of a hybrid approach for the management of coronary revascularization, ie left internal mammary artery to the left anterior descending artery through minimally invasive techniques combined with drug-eluting stents for the management of other lesions.3

The problem of cardiovascular disease will not be solved with devices alone. Recognizing the progression of atherosclerosis not only in non-stented segments but also inside the stents will turn interventional cardiologists into preventive cardiologists. The dramatic breakthroughs in the management of lipids and the cardiovascular effects of new drugs for the management of diabetes means that interventional cardiologists must be competent in these fields as well, since these therapies may become the most relevant “devices” in the future. A total paradigm shift may be underway in the management of stable ischemic heart disease. Diagnosis is now moving away from ischemia detection only to non-invasive coronary imaging in the assessment of physiology and anatomy. Right now the U.S. is behind other countries when it comes to the implementation of CT angiography, but I predict it will become the diagnostic catheterization laboratory of the future. Ad hoc percutaneous coronary interventions during invasive catheterizations may have been acceptable so far, but now with the ability to define coronary obstructions and their physiological significance non-invasively, we can better plan medical therapy, percutaneous coronary interventions, or surgery. Unlike ad hoc percutaneous revascularizations during invasive catheterizations, this will allow true informed consents and facilitate proper diagnoses in patients who may not have agreed previously to an invasive diagnostic procedure.4

It will not reduce the number of interventions but it will certainly guarantee that only the correct ones are performed. A critical consideration for this subspecialty is what the training should look like in this rapidly changing field. Not everyone will be an expert in every aspect, which is why training and continuing medical education will create the expertise required.

The future is always unpredictabe but if the past teaches us anything is that the field of interventional cardiology has a challenging and rewarding future. It is a new field of expertise where there is still much to be done. The launch of this new journal will give you the opportunity to disseminate new knowledge that will shape the future. As my term as editor of JACC: Cardiovascular Interventions was coming to an end I wrote an editorial that was published both in our journal and EuroIntervention5 I called it “The golden age of publishing in interventional cardiology”. Well, that age has not passed yet. I believe that the ability to publish good papers in quality journals has stimulated young investigators to do what needs to be done. This journal will be unique because it will be published in both English and Spanish. I hope that those who feel more comfortable using Spanish will be stimulated not only to read about the advances made on interventional cardiology, but also to contribute to its progress with more publications of their own research. This journal should be popular not only in Spain but throughout the Spanish-speaking countries in the Americas. Congratulations and best wishes to the editors of REC: Interventional Cardiology for this important contribution to our field.

CONFLICTS OF INTEREST

None declared.

REFERENCES

Access to medical literature has seen dramatic changes over the last few years. In less than two decades it has gone from a paperbased system to an online digital sending system. The advances made on computing and, above all, the Internet has revolutionized not only the way manuscripts are sent, but also how fast these get to the public (including reference manager software adaptable to the different format of various journals). This revolution has also touched the way information is being accessed these days. The databases generated at the beginning of the 21st century are «prehistoric» compared to the ones we use today. The digitalization of clinical histories and the creation of software for data mining purposes have accelerated exponentially the preparation and analysis of the data included in the studies. Even researchers have a much more transversal training and it is common to see research teams that are savvy in statistics and that facilitate data analysis. However, all these important changes are nothing compared to the actual access to general medical information. Even though access to medical literature is not actually open (something we will refer to later), access to a great deal of information is just huge. And all this has resulted in an exponential increase in the amount of papers that scientific journals receive on a monthly basis. Also, this is accentuated by the growing productivity of emerging countries or powers, such as China, that has noticeably multiplied the number of scientific papers published over the last few years. As an example, one of the leading journals in the field of cardiovascular disease, the Journal of the American College of Cardiology (JACC), received some 4000 manuscripts every year (3200 original papers/reviews) in a five-year span of time ever since the Spaniard Valentín Fuster took over as editor-in-chief back in 2014. Due to the acceleration in the generation of knowledge and how technical different subspecialties have become, the audience of cardiology journals is particularly interested in certain areas. The large volume and ongoing specialization of the manuscripts being sent to journals, added to the limited number of monthly publications lead to reduced success rates, since quality interesting papers for the cardiological community end up being rejected. Following the JACC example, the acceptance rate of original papers/reviews in the aforementioned span of time was barely 9%. These circumstances have resulted in the creation of sister journals of major journals such as those specialized in interventionism, imaging, heart failure, or arrhythmias, among others. It is expected that this increase in the number of manuscripts submitted to journals will go on and with it, the number of cardiology and subspecialty journals. This growth not only does not dilute the relevance of these journals, but it also promotes medical science while increasing access to knowledge and how this knowledge is spread. A common practice of high-impact journals for high-quality papers that are considered highly specialized is to offer the authors the re-submission of the manuscript to sister journals. In the aforementioned years, around 4% of the original papers/reviews published by the JACC were re-submitted and ultimately accepted by JACC: Cardiovascular Interventions. This practice accelerates the process of publication and guides authors on the possible interest of the journal at hand.

It is a paradox that, with all the digitalization we have seen so far, the main scientific journals, particularly the cardiology ones, still have the classic format of a paper journal with a limited number of papers being published each year. We believe that the actual global tendency will put this format to rest any time soon. It was with this idea in mind that the digital format open access journals were born. But yet despite its appeal, its impact is nowhere close to that of classical journals, which opens the debate on what readers and authors of journal manuscripts are really looking for. In a general sense, readers want to have access to information to know about the advances being made and be briefed on a particular theme. On many occasions, the reader cannot evaluate whether the studies published have been done correctly, or whether the existing literature on a particular issue has been reviewed appropriately. That is why the reader is in a quest for «leading» journals with a quality seal that will guarantee that the material being published has passed all the filters and has, therefore, been appropriately arranged and exposed for the public. In this sense, the role of editors is just essential since, in a way, they bring their own imprint to the journal. There are several quality seals for the assessment of journals, among them, the impact factor (IF) is the most popular one to assess the impact a journal has made among its audience. The IF is an annual «official» estimate - it is the measure between the citations received during a year to the articles published in a journal over the two previous years and the number of articles published during the same period. The higher the IF the higher the quality of a journal. The IF is estimated annually by a private company (Clarivate Analytics) that establishes the ranking of journals within their field of expertise. There are other metrics for the assessment of the impact journals make (Google Scholar¹ is becoming more and more popular these days) but, as it occurs with the IF, these metrics are imperfect and do not make assessments of all the quality aspects included in a scientific journal. As the JACC editor-in-chief says in an editorial from 2017², the IF is a curious fanciful metrics, since the presence of a highly cited paper (clinical guidelines would be the most significant example here) plays a very important role in the journal overall IF, even if the remaining papers do not draw much attention. On the other hand, the author of a paper wants to be published in a journal that will give his or her study the highest visibility possible for all the professional implications this brings to the author. Again, the IF plays a very important role when it comes to deciding what journal a paper should be sent to for evaluation purposes. Also, scientists are always looking for national and international funding for their studies, and most assessment agencies measure CVs based on the number and quality of the publications included, which is estimated by the IF and its position relative to other journals in the field. There is, therefore, some sort of vicious circle where readers and authors alike end up looking for the same journals, and it is these journals that will eventually choose, first hand, the most relevant papers, which will, in turn, guarantee good citation levels, high IFs and, eventually, the audience’s interest. Although this system has been highly criticized, there are so many factors orbiting around metrics, that it is hard to imagine a future where readers and authors will abandon these parameters.

A very relevant issue for the editorial committee of a scientific journal is to know what the target audience looks like and, especially, what type of information will be transmitted to them. On this regard, journals can be purely scientific (with predominant original papers) or educational (with predominant reviews on issues of high clinical interest). Journals usually go for some sort of mixed format between the two. However, some purely educational journals have ended up having very high IFs in the field of cardiology such as Nature Reviews Cardiology, that back in 2017 was positioned among the top spots in its field of expertise.

Over the last few years, the Internet revolution has resulted in the creation and vertical growth of social networks that have become a significant ingredient to spread the papers that are being published in scientific journals³. Social networks are essential when it comes to spreading research not only among scientists and doctors, but also among the general public, thus contributing to promote health. This aspect of information spread to non-medical audiences is critical and has become more and more relevant through the years. Recently created metrics such as the Almetric scores measure the impact of journals based on the activity they generate in the social media⁴. A study conducted on the Altmetric scores of the four most relevant cardiology journals revealed some interesting data⁵: a) the Altmetric scores from cardiology journals are usually very high; b) over half of the most popular papers were not original papers but editorials, points of view, clinical practice guidelines, and consensus documents; c) the papers with the highest impact based on this metric were those based on nutrition and lifestyles; and d) open access papers did not have a higher impact compared to pay per read papers.⁵.

One final relevant controversial issue is the cost associated with the publication of a paper and the access to this paper. Several journals -certainly those with the highest IFs of all- usually sign exclusivity deals with major publishing houses that will be formatting, publishing, and editing the papers. In order to have access to complete papers, universities, research centers and even individual professionals pay a subscription fee. This pay per read system certainly limits the spread of knowledge. Several authors decide to pay a fee when their paper has been accepted by a journal so that it is open access, and anybody can have access to it without having to pay a subscription. This fee -usually between 2500€ and 4500€- is already included in the public funding received by the authors. The journals send the manuscript to external unpaid reviewers who are only moved by responsibility and altruism. Therefore, we face a complex situation where the creator of the paper -the author-, the evaluator -the external reviewer and, on many occasions, the editorial committee- and the end user -the reader- pay for the journal in such a way that the economic benefits only go to the distributor of the material -the publishing house- that has only participated in the editing and distribution stages. The fact that studies conducted with public funds are not open access and, therefore, cannot be read by the community and the public, is highly questionable. That is why in some European countries like Sweden they have decided to cancel all subscriptions with big publishing houses in an attempt to push forward the open access to science⁶.

In sum, at the present time, medical journals are undergoing major changes, mainly due to the advance of the Internet and the social media. The future of this road is hard to predict but it seems that journals will end up being completely digital and will go open access for the readers, and with quality seals different than the classical IFs. Due to the huge amount of information available, the creation of subspecialty journals is a tendency that will become more and more popular in order to update professionals on their specific fields of expertise. REC: Interventional Cardiology already possesses many of these future traits. For this reason, we strongly believe the future looks bright ahead thanks to its excellent editorial team and parenting from Revista Española de Cardiología.

Conflicts of interest

The authors declare no conflicts of interest whatsoever.