After the first TAVI in Croatia in January 2011, a total of 71 interventions have been carried out to date. This procedure is currently offered to patients in three clinics (Clinical Hospital Centre Zagreb, Zagreb; Dubrava Clinical Hospital, Zagreb; Magdalena Clinic, Krapinske Toplice), with the number of implantations lagging behind the needed, primarily due to the cumbersome financial environment (the cost of the prosthesis being the limiting factor). A fair estimation of the needs for TAVI in Croatia can be based on the prevalence of this most common valvular disease (accounting for the estimates of the true symptomatic aortic stenosis) and runs between 200 and 250 cases per year (Figure 1).

The clinical characteristics of the patients treated should be in accordance with the true indication for this procedure — severe symptomatic aortic stenosis in patients with a high risk for surgery or deemed inoperable. Typically, these are older patients with numerous comorbidities, often with prior cardiac surgery and aged over 90. The procedure is performed either in general anaesthesia or deep sedation with local anaesthesia, depending on the vascular access site. In the majority of patients, the arterial system is accessed via the transfemoral route, with a small number of cases performed through the subclavian, transapical, direct aortic or transabdominal access points. Preprocedural imaging is essential for confirming the indication for aortic valve implantation, as well as for successful planning (primarily for determining the appropriate size of the valve and access route). Three imaging modalities are included in the majority of cases, transthoracic and transesophageal echocardiography, classic coronary angiography and aortography, and multislice computed tomography. The implementation of TAVI in routine practice is certainly slowed by the high cost of the procedure and current lack of proper reimbursement.

The ageing cardiac patients often present with severe mitral regurgitation, which carries a poor prognosis. These patients have an increased incidence of comorbidities with unacceptable risk for cardiac surgery for their mitral valve disease. On this background, percutaneous methods for mitral valve repair have been developed and tested. The Mitra- Clip system is one system, which has been studied most extensively and has also been approved for the use in the European Union. The principle of the repair mimics the surgical Alfieri stich technique (edge-to-edge repair). This is a highly complicated interventional technique, which requires extensive and precise preprocedural and periprocedural imaging, including 3D transesophageal echocardiography. The data on success rates and benefit of this procedure primarily stem from the EVEREST trial, which is a study plagued by methodological issues. One objection is that the success in this study was based on a mitral regurgitation smaller or equal to 2+, which under normal circumstances would not be a surgically acceptable result. While it seems that the procedure may convey benefit particularly to patients who are at high risk for mitral valve surgery, further data are needed to confirm if this technique, which imitates the repair, which has actually long been abandoned by the surgeons, represents a truly viable option for the treatment of mitral regurgitation. The implementation of MitraClip or similar devices in Croatia is most probably going to be delayed due to its enormous cost.

The nonsurgical closure of congenital septal defects in paediatric and adult population has been offered to Croatian patients for well over a decade. The data shown here (225 patients treated with this method to date) refer to adult patients only, treated in three centres.

There are two main indications for percutaneous septal defect closure. The undisputed indication is given in a patient with haemodynamically significant atrial septal defect (ASD). Percutaneous closure of ASD can safely be performed only in secundum type defects with appropriate anatomical properties. The position, size and shape as well as the presence of adequate rims is diagnosed with transesophageal echocardiography, which is essential both for planning and for the periprocedural guidance. Sinus venosus and primum type defects are not suitable for percutaneous closure and should be treated surgically. Another, less clear indication for septal defect closure is given in patients (typically younger) with cryptogenic stroke and patent foramen ovale, which is diagnosed in collaboration with neurologists and again confirmed by transesophageal echocardiography. The benefit of this procedure remains elusive, as recent studies have not convincingly confirmed the superiority of the procedure over medical treatment. The decision should be made on an individual basis and in close collaboration with neurologists. This procedure is available to Croatian patients on a regular basis, although at times hampered by financial aspects.

The main risk related to atrial fibrillation is the thromboembolic stroke, with emboli originating from left atrial appendage (LAA). There are a significant number of patients who are not able to continue the first-line treatment with oral anticoagulation. Surgical ligation, which is always performed as a part of another procedure, is routinely carried out if indicated, e.g. during mitral valve surgery. However, percutaneous devices have been developed to treat such patients. These devices use the transseptal route to reach the left atrium, where specially designed occluders are implanted in the LAA. Several studies have demonstrated possible benefit from this approach. The definite role of this procedure is yet to be established, especially with respect to the continuously growing use of novel oral anticoagulants (which show typically less bleeding with same or superior efficacy compared to warfarin). This procedure has not yet been performed in Croatia, primarily due to its relatively high cost.

Medical treatment of arterial hypertension is extremely effective in the majority of patients, with a vast body of data on reduction of both mortality and morbidity associated with this worldwide most prevalent cardiovascular condition. However, there is a significant minority of patients who have the so-called resistant hypertension. Depending on its definition and the vigour with which it is diagnosed (and poor compliance is excluded), the incidence of resistant hypertension may range from 5 to over 15% of hypertensive population. It is defined by persistent elevation of blood pressure above the target values while treating the patient with three or more antihypertensives of different classes, including a diuretic.

The principle of this intervention lies in targeting the sympathetic nervous system by bilateral destruction of the renal artery innervation, mostly by means of radiofrequency ablation using classic catheterization through the femoral artery. This in turn influences renal vascular resistance, renin activity, as wells as sympathic tone to the kidney and other organs. Studies have documented significant immediate and sustained (up to three years) blood pressure reduction.

The most recent ESC/ESH Guidelines for the management of arterial hypertension conclude that this method is promising, but still more data are needed from properly designed trials to determine the long-term efficacy and safety of renal denervation, especially in comparison with the best possible medical therapy.

This technique has been used in several Croatian centres since the beginning of 2012. In view of the prevalence of arterial hypertension, the number of patients treated so far has remained very low. Again, the use of renal denervation is far under the possible target numbers due to the cost of the catheters. (1-25)