In total, we conducted ten interviews across nine sites, three of which were university hospitals. Eight interviews were face-to-face and two via telephone. The interviews lasted between 20 to 35 minutes, the average time length being approximately 25 min. The sample is characterized by an over representation of cardiologists (nine out of ten respondents). The inductive approach revealed several factors that were mentioned by the interviewees within the following themes: collaboration between cardiologists and cardiac surgeons, reimbursement policies, requirements and skills needed to conduct the procedure, and medical advantages of the method. All of these themes are reflected by the model. We could identify potential facilitators and barriers to the adoption, implementation and diffusion related to the innovation itself, communication and influence, system readiness for innovation and system antecedents for innovation, the implementation process, and the outer context.
After the initial knowledge phase and getting in touch with the procedure for the first time, most participants rejected TAVI: “What nonsense. It cannot work this way.” (Cardiologist 4). After reconsideration and further discussion of TAVI, e.g., at internal meetings, the decision for implementation was made.
The respondents described multiple advantages of TAVI compared to the standard surgical procedure and drug treatment. Our interviewees generally mentioned medical outcomes and the improved quality of life of patients who underwent TAVI as an advantage. Several participants gave examples of how fast the patients recovered after the intervention and that the patients were able to leave the hospital much earlier compared to the standard surgery. In terms of medical outcomes, the results were not only perceived as better compared to the “classical” surgical procedure but were also directly visible to the physician and to the patient, as well as his or her relatives.
“You must have seen this, indeed. Patients are responsive right after the procedure, have little pain, at worst a bit of a pain in the groin, and can be mobilized in the evening or the next day… But they are responsive directly after the procedure, can eat, drink, talk with their families. They can be mobilized on the first day, third day down from the ICU, out of the house on the fifth day. You won’t find this with any other surgical procedure.” (Cardiologist 3)
“But it is an intervention in which the patient is basically walking around the next day. And with heart surgery that is, of course, very, very different. That’s it, especially for older persons… And I think the 80-year-old patient must quickly get out of the hospital and back into his environment and considering this, such a method has, of course, a huge advantage.” (Cardiologist 1)
One participant perceived the procedure as “highly complex” (cardiologist 7), a view that was shared. Even though TAVI proved compatible with existing practices, the method was seen as difficult to perform. Responses commonly indicated that TAVI required new knowledge and intensive training.
“But at the time we introduced that, when the treatment was new, each component had to be learned first […]” (Cardiologist 5)
“This is certainly a different dimension compared to a normal coronary intervention because you work with much, much thicker systems in marginal thin vessels.” (Cardiologist 5)
The respondents felt that TAVI has a steep learning curve. As the participant below estimated, it takes around 50 to 60 interventions to master the procedure; a number that was verified by another interviewee.
“I would say, until someone can reasonably do it, minimum numbers are not defined, but I think you need about 50 to 60 procedures…” (Cardiologist 4)
The risk of the procedure was linked to the available evidence. The respondents perceived the evidence base as good concerning patients aged 75 and older but found it not sufficient regarding younger patients. They arrived at the conclusion that the standard surgical procedure was still seen as superior with respect to this patient group. The criticism was driven by the lack of empirical knowledge concerning the duration of the implanted aortic valves.
Communication and influence
The physicians referred to two main sources of information. They consulted professional journals and national and international congresses, as well as opinion leaders at both the national and international level or “frontiers” as one interviewee said. Some of the respondents actively established contact with either one of the opinion leaders or with a medical device company in order to learn about the procedure. In the case of the medical device company that developed the artificial valves, they offered information and training sessions for the staff involved and promoted the implementation of the method. In one case, an interviewee referred to a conflict between two of the involved opinion leaders, where the cardiac surgeon rejected the method and the cardiologist supported it. The head physicians of the department of cardiology and cardiac surgery were reported to have played key roles in the implementation within the hospital, whereas support by the administration was only reported in one case. While some physicians stated that patients explicitly asked for TAVI instead of the standard treatment, this was perceived as rarely the case. More common seemed to be the fact that relatives and friends heard about the procedure.
“The patients who inform themselves and ask for it are those to whom one would offer it reluctantly because these are the younger patients…” (Cardiologist 4)
Two respondents mentioned that the hospitals they work for organize events to facilitate the dissemination of TAVI, either targeting general practitioners or patients. In contrast, one participant emphasized that there are no efforts in “advertising.”
System readiness and system antecedents
Pressure for change was widely reported by the respondents. The interviewees named a combination of different aspects as reasons for this pressure, most notably the organizational self-image, as well as competition between hospitals. Hospitals that consider themselves as innovative were reported to having wanted to implement the procedure and be among the early adopters, as the following respondent replied:
“Then there are early adopters, who quickly adopt good and promising practices, that’s us. And then there are the laggards, late adopters, and that is what we do not want to be.” (Cardiologist 3)
The interviewees referred to organizational requirements needed to implement the procedure. In multiple interviews, the heart team was mentioned as a central player in considering the implementation of the method. The views of the participants differ considering the composition of the heart team. While in most interviews it was mentioned that a cardiac surgeon, an interventional cardiologist, and an anesthesiologist should be present during the procedure, the comment below illustrates that reality could look different:
“…the heart team should not exist merely on paper. In other words, that there is a surgeon somewhere who is only on standby, or who says ‘yeah, sure’.”(Cardiologist 8)
The opinions about the required staff changed according to the type of hospital. Interviewees working in university hospitals found it inevitable to have an in-house department for cardiovascular surgery, while those working in smaller and specialized hospitals did not share this view. Hospitals without such a department sought expertise from outside and hired an external surgeon especially for TAVI.
“This cannot be managed by a normal house where only standard operations are conducted and without a cardiac surgery. You have to say this. And houses that do it, which have the logistics, emphasize the safety aspect and that they cover the all safety issues…” (Cardiologist 4)
The most evident factor mentioned by nearly all interviewees was the internal collaboration with other medical departments, most notably between cardiologists and cardiac surgeons. Many respondents described this struggle as a factor influencing the adoption decision and slowing down or interrupting the implementation process, as the statements below indicate:
“These are the nuts and bolts… Because, often the teamwork of cardiologists and cardiac surgeons is not given…This is a major problem because the interventional cardiology has expanded into many areas of heart surgery…” (Cardiologist 5)
“Because, especially in the initial phase… we failed because of the resistance of the cardiac surgery without which, of course, it didn’t work at that time, or still does not work.” (Cardiologist 1)
The respondents commented that TAVI created an issue of competence. While the cardiologists felt eager to implement the method, the cardiac surgeons were described as reluctant and refusing. Some interviewees felt that this was because of a “restructuring” of those two medical disciplines. More and more treatments, which originally belonged to the field of work of the cardiac surgeons, have now become the responsibility of the cardiologists, as the following statement indicates:
“With the introduction, I think there was concern in all houses… I believe this was the case everywhere… It’s psychological. You delve into the innermost of the heart or in the core competence of cardiac surgery. The colleagues got used to the fact that cardiologist do more and more. They have taken pacemakers and defibrillators, all previously done by surgeons… But if someone wants to have a new aortic valve, then he needs to ask us.” (Cardiologist 4)
After the conflict had been solved, one respondent felt that “…the TAVI program has actually resulted in a much closer cooperation with the cardiac surgery.” (Cardiologist 1). The interviewee described that after initial denial, a restructuring took place which created space for new cooperation between both departments. The implementation phase took about 1 year, as some of the participants confirmed.
The outer context
Concerning the extra-organizational context, the respondents described economic as well as social influences on the adoption decision. As mentioned above, there is not only an ongoing debate about TAVI in journals but in public media as well. In particular, the public debate was perceived as generally useful, although misguided. While one respondent described the discourse as “one-sided,” focusing either on cost issues of TAVI or on its medical outcomes. The statement below indicates yet another perception:
“I’ve perceived the discussion as quite controversial and as it should be. So I thought that this was really impressive, the way that it was discussed within the society… What issues have been addressed and what has been discussed. I haven’t experienced this with other procedures….. Probably because it was done too often.” (Cardiologist 3)
The approval system for medical devices in Europe and the reimbursement system in Germany, often described as “innovation friendly” in comparison to the US medical device regulation, was a theme often brought up during the interviews. Being able to receive reimbursement at an early stage was regarded as one of the main drivers facilitating the diffusion of TAVI. The DRG rate was perceived as high, but most of the participants did not see TAVI as a way to generate as much profit as argued in the public debate. Some interviewees did say, however, that it could be a way to generate money if done in large amounts and, therefore, could be interesting for hospitals. The missing quantitative limitation regarding the maximum and minimum amount of procedures and the fact that no mandatory requirements concerning the diagnosis and infrastructure of hospitals using TAVI exist were also mentioned as factors positively influencing the diffusion rate.