Already as an adolescent, he was intrigued by natural science-oriented detective work such as searching for evidence. When he started his studies in medicine, forensic lectures were those he found the most fascinating. “They were actually intended for law students, but we all attended them. Once per semester, there was a public dissection, and that was of course more exciting to us than our dry first semester subject matter,” he recounts, laughing mischievously. Gerhard-Paul Diller eventually chose cardiology. After graduating in Munich, his clinical career brought him to the London Royal Brompton Hospital, which is one of the world’s biggest centers for adults with congenital heart disease (ACHD). The latter has remained his central field of research and work until today. The ACHD specialist practises medicine at the department of congenital heart disease (ACHD) and heart valve disease at the Muenster university hospital. His latest project OptAHF is the biggest healthcare study that has ever been conducted on this subject in Germany. At the National Register in Berlin, we talked to him about his project and the trouble with research funding.

The Heart-Explorer: You have just come from a meeting with colleagues of the National Register on your recent study OptAHF. What is the subject of this research project?

Gerhard-Paul Diller: OptAHF refers to optimizing the health care situation of patients with congenital heart disease. We seek to know more about the quality of medical care for adults with congenital heart disease and to determine the need for improvements. Our focus is not limited to cardiac care, but actually includes any medical procedure. Like others, patients with congenital heart disease might also have to be cured from an infected appendix or they may have other diseases requiring an intervention. The big question here is in how far such procedures should take place in a specialized environment with a focus on congenital heart disease, where anesthetists and surgeons are appropriately trained and prepared.

„International studies suggest immense accumulated needs.“

The Heart-Explorer: So you fear that the outcome in patients who have not received treatment in an appropriately specialized institution is worse as compared to those receiving specialized care?

Gerhard-Paul Diller: We cannot rule out this possibility. In fact, we even have to assume it is true. The question has already been investigated by colleagues from Canada. They have found that patients that are not connected to an ACHD center show an increased mortality rate. There are data from the USA that prove that these patients show up at the emergency department with complications more frequently than others.

„In the meantime, a lot can be done for pregnant heart patients. But is it actually done across the whole country?“

The Heart-Explorer: In what way? You were referring to the example of an appendectomy. Does your survey also monitor different cardiac treatments for patients with specific congenital heart defects?

Gerhard-Paul Diller:  The thing is that we do not have sufficient knowledge yet regarding the ideal medical care for this patient group. The number of children growing up to become adults with this underlying chronic disease has been growing continuously since the seventies. We see many patients around 40 at our hospital nowadays. This is a relatively new development. Therefore, our study not only focuses on the provided healthcare in general, but also, and especially, on the cardiac treatment in, say, congenital coarctation of the aorta, a constriction of a vessel. For example, we will try to investigate in which cases a catheter-based intervention is a sensible thing to do and in which cases patients are better off being treated with certain medication such as drugs for high blood pressure.

The Heart-Explorer: What else is the study about?

Gerhard-Paul Diller: The second big subject is pregnancy, since cardiac disease is still one of the major causes of maternal death. This does, in fact, occur only rarely in our part of the world. However, women with congenital heart disease bear a great risk. There are complex heart defects involving cyanosis and pulmonary hypertension that are known to have a maternal death rate of as high as 50 percent. This is aggravated by the fact that these women have poor chances of carrying their child to term without difficulty because the lack of oxygen has detrimental effects on the fetus. However, a lot can be done in the meantime. There is more substantiated counseling for these women nowadays, medication that has a negative effect on the fetus can be discontinued, etc. The question is: does this actually happen across the whole country? This extends to delivery. Is a Cesarean section indicated or does it put higher stress on the complete cardiovascular circulation than spontaneous delivery would? And where do these women deliver? Is the delivery accompanied by a team of cardiac specialists to facilitate planning for emergency cases? We seek to answer also these questions.

„For depth of data we count on the National Register.“

The Heart-Explorer: How do you proceed?

Gerhard-Paul Diller: Nationwide data regarding the healthcare provided to patients with congenital heart disease are not available yet. What is available, however, are the databases of the health insurance providers, the data of the Federal Office of Statistics, which we draw on for our study, as well as the data of the National Register. We are lucky that Barmer GEK, one of the biggest health insurance providers in Germany, takes part in our project. Barmer GEK has approximately 10 million members and provides us with data covering a period of about ten years. It comes without saying that this collection only includes data that are relevant for accounting. For depth of data we count on the National Register, which holds specific disease-related and treatment-related data. This is particularly interesting because we can select different patient groups with special characteristics and match their data.

The Heart-Explorer: Based on your practice, do you have an idea which results you might get?

Gerhard-Paul Diller: As you know, we are facing the problem that some patients do not adhere to regular follow-up visits at specialized heart centers or doctors. The different data we will be working with give us the ability to analyse what this means for patients for the first time. For this purpose, we will conduct one of the first Big Data analyses in this field in Germany.

„Big Data analyses are uncharted territory in Germany.“

The Heart-Explorer: Big Data analyses sound promising particularly in the realm of research. On the other hand, this topic causes many citizens discomfort, especially regarding their own data.

Gerhard-Paul Diller: As a matter of principle I can understand this very well. However, when it comes to our research, this fear is unfounded. The enormous benefit of the possibility to analyze and compare huge volumes of data within shortest time significantly outweighs potential risks in our case. It does make a difference if you analyze twenty or a million datasets. This is still uncharted territory in Germany. In this connection we also benefit from the National Register's longstanding experience regarding data protection and data management. They have both sufficient experience and practice to safeguard each patient's protection, as well as valid results.

„The research infrastructure has to be backed by public funds. Otherwise, this whole thing cannot work.“

The Heart-Explorer: You are referring to research funding. How hard is it to acquire sufficient funds?

Gerhard-Paul Diller: Fortunately, the innovation committee of the Federal Joint Committee (G-BA) rated the project's importance as high and is funding it accordingly. But of course: everyone conducting studies also knows: this is a frustrating field. You write an application, which is declined, and then you write another one, and it fails again, and then, sometime, you are successful. I think this is the case for everyone.

The Heart-Explorer: So this is typical fare for the researchers of the Competence Network?

Gerhard-Paul Diller: Yes, I am sure this is true for all scientists. What I find alarming, however, is that hardly anyone seems to acknowledge the necessity of providing financial security to such a research infrastructure as set-up and maintained by the Competence Network with its National Register. It is the vital platform for researchers, academics, clinicians and all those interested in research in this field in Germany. It would be nonsense for sure if we received a fixed rate of public funding for one or two studies per year. For studies have to prove their worth, they have to be worthwhile. Thus, it does not make much sense to just pour money on us and say: go ahead. But the structure, the basic equipment, the platform, they all have to be secured by public funds. Otherwise, this whole thing cannot work.

„The challenges single researchers have to face are too many and too big.“

The Heart-Explorer: Which role does the National Register play for research and science in general?

Gerhard-Paul Diller: A few weeks ago we welcomed a delegation from England at the Competence Network. They are currently trying to set-up such a register. This means that also on an international scale researchers recognize that we have a structure here that has been planned with foresight and which increasingly bears fruit. Without the National Register, research in the field of congenital heart disease would not even be thinkable. The challenges are too many and too big. Data and sample logistics, legal prerequisites, ethical guidelines, data protection - these are all great obstacles for single scientific institutions. And it would not be efficient at all if we, the researchers, would have to deal with these issues. Unlike us, the staff members of the National Register do this on a daily basis and are accordingly experienced.

„The patients rely on the results of research. This is a worthwhile investment in the future.“

The Heart-Explorer: In an ideal world, what would have to happen to safeguard cardiac research in Germany as a location for research with the current quality and extent, covering the whole field from congenital to acquired heart disease?

Gerhard-Paul Diller: As a health economist I am a bit prejudiced here. As a matter of principle, I am convinced that a more thorough analysis of the relevance of this patient-oriented research for society as a whole, as well as in terms of national economics, should only have one result; and that is investing in this globally unique research infrastructure in the field of congenital heart disease. The patients rely on the results of this research. They are entitled to physical integrity and quality of life just as anybody else. Hence, the Register should be supported in any case to be able to gain a foothold in the digital era of the 21st century. This is a worthwhile investment in the future. We have to communicate also this more explicitly. Over 50,000 register members donate their data and samples. This is a great act of faith and leads to great responsibility. In the best of all possible worlds, society appreciates all its members' health and provides respective conditions.

The Heart-Explorer: Professor Diller, thank you for the interview.