"Artificial heart" as a last chance... Assoc. Prof. Dimitar Kyuchukov in front of FACTS

Modern cardiology and cardiac surgery are saving more and more patients, but for some of them the battle does not end with overcoming the acute condition. On the contrary - they reach the most severe stage of heart failure, in which their own heart is no longer able to ensure the normal functioning of the body. The so-called "artificial heart" is no longer science fiction. Modern mechanical pumps can support or replace the function of the heart in the most seriously ill patients. How does this technology work, for whom is it suitable and how far has Bulgaria come in its application… Assoc. Prof. Dimitar Kyuchukov, Head of the Cardiac Surgery Clinic at the National Cardiology Hospital (NCH), spoke to FACTI.

- Assoc. Prof. Kyuchukov, we are increasingly talking about an “artificial heart“ as a last chance for patients with terminal heart failure. What are the specific criteria by which you decide that a patient has already reached the point where a mechanical pump is the only real chance to be saved?
- The decision to implant a mechanical circulatory support system is one of the most responsible decisions in modern cardiac surgery. It is not based solely on data on the suppressed pump function or the severity of symptoms, but on the overall assessment of the patient's condition, in which colleagues from different specialties participate. In general, the device is indicated for patients with advanced heart failure, in whom severe symptoms persist despite optimal drug therapy, frequent hospitalizations are required, and cardiac function progressively deteriorates. The evolution of the condition quickly leads to damage to other organs (lungs, kidneys, and liver) due to insufficient blood supply and the refusal of advanced therapies - resynchronization therapy, a system for mechanical circulatory support, and transplantation. This always leads to irreversible multi-organ damage and survival shortened within a year. Before proceeding with surgery, the function of the heart, the condition of the lungs, kidneys, and liver, the presence of concomitant diseases, as well as the patient's ability to tolerate the surgery and subsequent therapy are assessed. Of utmost importance for the ultimate success of the therapy is the timing of referral. We should not wait for the patient to reach a state where all other options have been exhausted and the risk of this intervention is already too high. Mechanical support can be life-saving, but only when applied to a properly selected patient and at the right time.

- About 24-25 people per year in Bulgaria need such expert medical care. What is the real number of patients who could be suitable for artificial heart implantation, and how many of them are currently left without this opportunity?
- The indicated 24-25 patients per year are a starting point for an assessment of needs, which is calculated by interpolation of data in European registries, according to which on our continent the average number of implanted devices per year is four people per million population. Unfortunately, Bulgaria lags behind this figure due to a number of complex reasons, one of which is the untimely referral to a specialized center for the treatment of heart failure, long before the development of terminal organ damage.
In order to determine how many patients in Bulgaria would benefit from such treatment and how many of them do not receive it, a national registry of patients with advanced heart failure is needed, as well as systematic monitoring of the results in specialized hospitals. I am convinced that the real need must be established at the national level. Only in this way can we plan the necessary capacity, financing and organization of treatment.

- How does the operation itself proceed and what does life after the implantation of a mechanical pump mean for the patient - can a person return to a normal life, work, travel and what restrictions remain?
- Implantation of a device for mechanical circulatory support is a complex cardiac surgical intervention, the success of which requires precise preoperative preparation and careful planning. Our goal is not simply to prolong life, but to give the patient the opportunity to live as fully and independently as possible within the framework of medical limitations. The most commonly used and successful model of these systems is a variant in which only the left ventricle is supported. After the operation, the patient undergoes a period of intensive monitoring, gradual mobilization and specialized rehabilitation. After stabilization, many patients can restore a significant part of their daily activities, move independently and, under appropriate conditions, travel. However, this does not mean a life without restrictions. Constant care for the device, regular medical examinations, strict adherence to the prescribed therapy and education of both the patient and his relatives are necessary. Particular attention is paid to the prevention of infections, thrombosis and bleeding.

- You say that you have trained a specialized multidisciplinary team at the National Clinical Hospital and have received support from foreign colleagues. What exactly should such a team be responsible for and are there enough specialists in Bulgaria to maintain the program sustainably, and not just for a few operations per year?
- Implanting a mechanical circulatory support system is not an activity that can be successfully carried out only by cardiac surgeons. This is a comprehensive program in which cardiologists, cardiac surgeons, anesthesiologists and resuscitators, imaging specialists, nurses, perfusionists, rehabilitators and other medical specialists participate. It is necessary for each member of the team to know the specifics of the device, possible complications and behavior in emergency situations. Equally important are the organization of preoperative assessment, postoperative care and long-term follow-up. The preparation of such a team requires training, practical experience and constant improvement. The support of colleagues from established international centers is extremely valuable, especially in the initial stage of the program.
In Bulgaria, we have highly qualified medical specialists, but the sustainable development of this activity requires that they be united in well-organized centers with the necessary equipment, financing and the ability to maintain expertise. It is not just about performing a certain number of operations, but about ensuring continuous readiness for the treatment and follow-up of these patients - all tasks that we have been preparing for the solution of at the National Cardiology Hospital for two years now.

- The device itself is reimbursed by the NHIF for a certain number of patients, but the subsequent logistics and complex care remain a heavy expense for the hospital. Where exactly is the biggest financial problem - in the operation, resuscitation, consumables, follow-up or long-term care?
- The main problem is that the treatment does not end with the implantation of the device. The operation itself is only one stage of a long and resource-intensive process. It is necessary to ensure preoperative diagnostics, surgical intervention, prolonged intensive care if necessary, specialized consumables, patient education and long-term follow-up.
Additional resources are also needed in the event of complications, the resolution of which requires other complex, high-tech and expensive devices and therapies. Therefore, I would not define a single stage as the main financial problem. The essential thing is that the costs are distributed over time and cover many different activities, some of which are not covered.
The ideal financing model would be one that takes into account the entire treatment process - from patient selection to long-term care. Only in this way can such a program be sustainable, without putting the medical institution at constant financial risk.

- The artificial heart is often presented as an alternative when there is no donor. In Bulgaria, the problem with donation remains serious. How many patients who could be supported with a mechanical pump are actually waiting for a transplant, and how many of them do not live to see a suitable donor?
- Mechanical circulatory support has an important place in the treatment of patients with advanced heart failure, especially when the options for medical treatment have been exhausted and transplantation cannot be performed in a timely manner. The main indication for implantation of the device is as a bridge to transplantation. In a significant proportion of those in need, who for various reasons are not suitable for transplantation, it can be used as a lifelong therapeutic option.

There are a significant number of patients who, for example, are over 65 years of age, are not candidates for transplantation, and the implantation of such devices can extend their lives by at least 10 more years.

It should be emphasized that it is necessary to distinguish between all patients on the waiting list for heart transplantation and those who meet the criteria for mechanical support. These are overlapping groups, but are not entirely identical.
In order to indicate the exact number of patients who could be supported by a mechanical pump, as well as the number who died before a suitable donor was available, we need to have up-to-date data from the transplant registry and from the centers that follow up on these patients who, unfortunately, are not supported. Mechanical support is not a substitute for donation and transplantation. It complements the treatment options and can provide a chance for patients for whom time is a critical factor.

- One of the serious problems of Bulgarian cardiac surgery is that seriously ill patients are often referred too late. Are there cases in which the patient is already in such a serious condition that even the “artificial heart“ cannot be applied?
- Yes, this is a real medical problem. There is a point in time when heart damage is accompanied by such severe disorders in the function of the kidneys, liver, lungs or other organs that the risk of implanting a mechanical system becomes unacceptably high or completely hopeless. A typical scenario is the development of severe right heart failure. In other patients, irreversible neurological damage or other irreversible organ damage occurs, which predetermine the negative outcome of undertaking therapy.
That is why early referral to a specialized center is so important. When the patient is assessed in time, we have the opportunity to monitor the development of the disease, optimize the treatment and plan the appropriate intervention before irreversible damage to other organs occurs.
Not every patient with advanced heart failure is suitable for mechanical support, but everyone deserves a timely expert assessment and an optimal treatment plan, because every life matters and no one is insured against the risk of getting sick.

- NKB already has experience with extremely complex and innovative cardiac surgical interventions – in 2025, your team performed a complete replacement of the aorta with a new generation prosthesis for the first time in our country. What is the next technological level you want to reach - and how far can mechanical heart support develop in Bulgaria?
- For us, the development of cardiac surgery is not limited to the introduction of new devices or the performance of single high-tech operations. The real goal is to integrate these capabilities into a comprehensive treatment system that provides good results and is sustainable over time.
In the field of mechanical circulatory support, the next step is to develop a program that covers the entire patient journey - from early diagnosis and proper selection to implantation, rehabilitation and long-term follow-up. Technologies are constantly evolving. Systems are becoming more compact, management algorithms are being improved, and work on reducing complications and improving quality of life continues. It is important for Bulgaria to create conditions in which patients and their treating physicians have access to these achievements. This requires not only modern equipment, but also trained specialists, scientific cooperation, adequate funding and the opportunity to gain clinical experience.

Our ambition is for NKB to continue to develop highly specialized cardiac surgery and to offer patients modern treatment options tailored to their specific medical needs.

I can proudly say that we are the only clinic in Bulgaria that shares its results with the European registry for cardiac surgeries and we are subject to constant monitoring, which so far ranks us among the top not only in terms of the severity and complexity of the surgeries performed, but also in terms of achieved results, which is extremely satisfying.
When we talk about these patients, we are talking about people for whom without treatment the prognosis may be extremely short.

- What needs to change in the system so that the “artificial heart“ not be an exclusive medical option, but real access to treatment for every patient who meets the medical criteria?
- Firstly, we need to improve the early recognition of advanced heart failure and the timely referral of patients to specialized centers. This is crucial, because even the most advanced technology cannot fully compensate for the consequences of too late treatment.
Secondly, we need to build a sustainable financing model that covers not only the device, but also the entire treatment and follow-up process. The necessary human resources, competencies, consumables and organizational readiness must be provided.
The third important element is coordination between medical institutions. Patients must be able to be referred in a timely manner, and treatment decisions must be made by multidisciplinary teams with proven expertise and a real track record of good results. Last but not least, we need to have reliable national data on the number of patients, the results of treatment and the real needs of the system.
Mechanical circulatory support is a treatment that can completely change the outlook for certain patients with severe heart failure. Our task as doctors is to ensure their timely selection and quality treatment. The task of the health system is to create conditions for these patients to receive the necessary care regardless of financial and organizational constraints. Every life matters.