The cost-effectiveness of transcatheter aortic valve implantation: exploring the Italian National Health System perspective and different patient risk groups

OBJECTIVES

To assess the cost-effectiveness (CE) of transcatheter aortic valve implantation (TAVI) in Italy, considering patient groups with different surgical risk.

METHODS

A Markov model with a 1-month cycle length, comprising eight different health states, defined by the New York Heart Association functional classes (NYHA I-IV), with and without stroke plus death, was used to estimate the CE of TAVI for intermediate-, high-risk and inoperable patients considering surgical aortic valve replacement or medical treatment as comparators according to the patient group. The Italian National Health System perspective and 15-year time horizon were considered. In the base-case analysis, effectiveness data were retrieved from published efficacy data and total direct costs (euros) were estimated from national tariffs. A scenario analysis considering a micro-costing approach to estimate procedural costs was also considered. The incremental cost-effectiveness ratio (ICER) was expressed both in terms of costs per life years gained (LYG) and costs per quality adjusted life years (QALY). All outcomes and costs were discounted at 3% per annum. Univariate and probabilistic sensitivity analyses (PSA) were performed to assess robustness of results.

RESULTS

Over a 15-year time horizon, the higher acquisition costs for TAVI were partially offset in all risk groups because of its effectiveness and safety profile. ICERs were €8338/QALY, €11,209/QALY and €10,133/QALY, respectively, for intermediate-, high-risk and inoperable patients. ICER values were slightly higher in the scenario analysis. PSA suggested consistency of results.

CONCLUSIONS

TAVI would be considered cost-effective at frequently cited willingness-to-pay thresholds; further studies could clarify the CE of TAVI in real-life scenarios.

1634 3D transoesofageal echocardiography in detection of anterior leaflet laceration during mitraclip implantation

Background

MitraClip is a percutaneous way of treatment of mitral regurgitation. Recent trials demonstrate its value in modifying prognosis of patients with functional mitral regurgitation. During MitraClip implant imaging with 3D TEE is mandatory to guide the procedure and monitoring the results. Unfortunately, laceration of mitral leaflets is a well-described complication of Percutaneous Mitral valve repair by implantation of MitraClip. 3D TEE can be useful even to detect complication of the procedure and in particular leaflets lacerations. Here we describe a case where 3D TEE was capable to recognize and visualize a laceration in the anterior leaflet (AL) and we assume some mechanisms leading to this complication.

Methods

An 83 years old man with post-ischemic severe functional mitral regurgitation underwent to MitraClip implantation. The mitral valve shows a severe tenting and annulus was deformed and dilated.

The procedure was performed under fluoroscopic and 3D TEE guidance (Philips iE33). Due to the large central regurgitation and large coaptation gap, we decide to implant MitraClip XTR, this is the larger device 5 mm longer.

Results

A single MitraClip XTR was implanted in the central scallop (A2-P2) in the region of the larger jet, after device positioning a further jet was detected in the region of implant and the original jet was unchanged.

Using 3D color complete volume and X-plane reconstructions we recognize that the jet originates between the clip and the basal aspects of AL. Without color Doppler in 3D zoom and X plane reconstruction, a continuum solution was suspected in the body of AL but the shadow of the delivery system partially masked the region. After removal of the device, perforation of AL was clearly depicted also with 3D zoom without color Doppler. The patient was surgically treated and inspection confirmed the laceration and shows a worn thin AL. The laceration of AL can be caused by the tension on a thinned tissue carried out by the large device. The severe tethering and annular dilatation with a marked distance between anterior and posterior leaflet at the tip of the device may have been a determinant factor in the tear occurrence.

Conclusion

3D TEE can clearly depict lacerations of leaflets during MitraClip implantation. Preoperative extensive analysis of valve geometry and inspection of leaflets searching for a thinned region can avoid intraoperative complications. The distance between leaflets at the expected tips of the MitraClip can be a predictive parameter of tension applied on the leaflets and of the risk of tearing.

Abstract 1634 Figure. Image 1

Reduction of blood coagulation and monocyte-platelet interaction following the use of a minimal extracorporeal circulation system (Synergy®) in coronary artery bypass grafting (CABG)

Cardiovascular surgery with cardiopulmonary bypass (CPB) induces activation of blood coagulation and systemic inflammation involved in post-operative complications. Our study evaluated the impact of the minimal extracorporeal circulation (mini-CPB) system (Synergy®, Sorin Group) on these functional aspects. Twenty patients were randomly assigned to standard CPB (n=10) or to Synergy (n=10). Platelet expression of PAC-1, and monocyte/granulocyte-platelet conjugates were evaluated by flow cytometry. A leukocyte-platelet adhesion index was calculated after cell number normalization. ELISAs were performed to measure IL-6 and TNF-α, thrombin-antithrombin III complexes (TAT), prothrombin fragments (F1+2), β-thromboglobulin (β-TG) and sP-selectin (sCD62P). Blood samples were drawn at the time of anesthesia (T1), at the end of CPB (T2), and at 4 (T3) and 24 hours (T4) after weaning from CPB. All patients were similar for clinical characteristics. When compared to standard CPB, the Synergy showed lower levels of the monocyte-platelet adhesion index at T2 (0.023 ± 0.005 vs 0.063 ± 0.013, P = 0.0092) and T4 (0.031 ± 0.003 vs 0.055 ± 0.005, P = 0.0017), TAT complexes at T2 (27.175 ± 5.967 vs 86.592 ± 5.415, P = 0.0005) and T3 (26.977 ± 2.468 vs 45.146 ± 4.365, P = 0.0041), F1+2 fragments at T2 (2.222 ± 0.226 vs 4.249 ± 0.292, P = 0.0009), and sP-selectin at T3 (115.17 ± 19.623 vs 169.554 ± 19.709, P = 0.0703) and T4 (108.542 ± 6.429 vs 140.799 ± 14.771, P = 0.0833). In summary, the Synergy exhibited a lower post-operative activation of blood coagulation, together with a reduced interaction between circulating monocytes and platelets.

Is the low tri-iodothyronine state a crucial factor in determining the outcome of coronary artery bypass patients? Evidence from a clinical pilot study

The cardiovascular system is an important target for thyroid hormones. The present study evaluates the changes affecting thyroid hormone metabolism during and 6 days after coronary artery bypass and their relationship with the post-operative outcome of the patients. Thirty-three patients were enrolled in the study; their thyroid hormone profiles were determined at 13 sampling points during surgery and for 6 days afterwards. Serum total tri-iodothyronine (T3) and free T3 (FT3) concentrations decreased significantly after surgery (P<0.001) and they remained significantly low until the end of the study. Free thyroxine (FT4) and T4 declined significantly immediately after surgery (P<0.05 for FT4, P<0.001 for T4) but they returned to baseline values (24 h and 96 h post-surgery respectively). Serum reverse T3 increased remarkably 36 h after surgery (P<0.001) and remained significantly higher than the baseline value throughout the study. A relevant finding was that the days of post-operative hospitalization (10+/-3 days, means+/-S.D.) was inversely correlated with the slope of the recovery of T3 concentration (P<0.001) or with the area under the plasma curves of T3 (P=0.024, time range 72-144 h) and the FT3/FT4 ratio (P=0.037, time range 72-144 h) during the post-operative period. Our data suggest a prolonged reduction of T4 to T3 conversion in patients undergoing cardiac surgery and indicate that the recovery period is the most critical in the evaluation of a possibly successful approach for T3 substitutive therapy.