Current status and future perspectives of prosthetic valve selection for aortic valve replacement

Efficacy of protocol-based pharmacotherapy management on anticoagulation with warfarin for patients with cardiovascular surgery

WHAT IS KNOWN AND OBJECTIVE

Anticoagulation therapy with warfarin requires periodic monitoring of prothrombin time-international normalized ratio (PT-INR) and adequate dose adjustments based on the data to minimize the risk of bleeding and thromboembolic events. In our hospital, we have developed protocol-based pharmaceutical care, which we called protocol-based pharmacotherapy management (PBPM), for warfarin therapy. The protocol requires pharmacists to manage timing of blood sampling for measuring PT-INR and warfarin dosage determination based on an algorithm. This study evaluated the efficacy of PBPM in warfarin therapy by comparing to conventional pharmaceutical care.

METHODS

From October 2013 to June 2015, a total of 134 hospitalized patients who underwent cardiovascular surgeries received post-operative warfarin therapy. The early series of patients received warfarin therapy as the conventional care (control group, n=77), whereas the latter received warfarin therapy based on the PBPM (PBPM group, n=68). These patients formed the cohort of the present study and were retrospectively analysed.

RESULTS

The indications for warfarin included aortic valve replacement (n=56), mitral valve replacement (n=4), mitral valve plasty (n=22) and atrial fibrillation (n=29). There were no differences in patients' characteristics between both groups. The percentage time in therapeutic range in the first 10 days was significantly higher in the PBPM group (47.1%) than that in the control group (34.4%, P<.005). The average time to reach the steady state was significantly (P<.005) shorter in the PBPM group compared to the control group (7.3 vs 8.6 days).

WHAT IS NEW AND CONCLUSION

Warfarin therapy based on our novel PBPM was clinically safe and resulted in significantly better anticoagulation control compared to conventional care.

ANMCO/SIC/SICI-GISE/SICCH Executive Summary of Consensus Document on Risk Stratification in elderly patients with aortic stenosis before surgery or transcatheter aortic valve replacement

Aortic stenosis is one of the most frequent valvular diseases in developed countries, and its impact on public health resources and assistance is increasing. A substantial proportion of elderly people with severe aortic stenosis is not eligible to surgery because of the advanced age, frailty, and multiple co-morbidities. Transcatheter aortic valve implantation (TAVI) enables the treatment of very elderly patients at high or prohibitive surgical risk considered ineligible for surgery and with an acceptable life expectancy. However, a significant percentage of patients die or show no improvement in quality of life (QOL) in the follow-up. In the decision-making process, it is important to determine: (i) whether and how much frailty of the patient influences the risk of procedures; (ii) how the QOL and the individual patient's survival are influenced by aortic valve disease or from other associated conditions; and (iii) whether a geriatric specialist intervention to evaluate and correct frailty or other diseases with their potential or already manifest disabilities can improve the outcome of surgery or TAVI. Consequently, in addition to risk stratification with conventional tools, a number of factors including multi-morbidity, disability, frailty, and cognitive function should be considered, in order to assess the expected benefit of both surgery and TAVI. The pre-operative optimization through a multidisciplinary approach with a Heart Team can counteract the multiple damage (cardiac, neurological, muscular, respiratory, and kidney) that can potentially aggravate the reduced physiological reserves characteristic of frailty. The systematic application in clinical practice of multidimensional assessment instruments of frailty and cognitive function in the screening and the adoption of specific care pathways should facilitate this task.

Computer-Assisted Transcatheter Heart Valve Implantation in Valve-in-Valve Procedures

Objective

Valve-in-valve (ViV) procedures are increasingly being considered as an alternative to redo surgery for the treatment of degenerated bioprosthetic heart valves in patients with excessive reoperative risk. The objective of our study was to evaluate the feasibility of computer guidance in transcatheter heart valve (THV) implantation during ViV procedures.

Methods

Preprocedural electrocardiogram-gated computed tomography–scan images were processed using semiautomatic segmentation of the degenerated bioprosthesis’ radiopaque landmarks and of the ascending aorta. Virtual three-dimensional (3D) reconstructions were created. A virtual plane was subsequently added to the 3D reconstructions, indicating the optimal landing plane of the THV inside the tissue valve. Within a hybrid operating theater, a 3D/2D registration was used to superimpose the 3D reconstructions, while dynamic tracking was allowed to maintain the superimposition onto the fluoroscopic images. The THV was afterward implanted according to the optimal landing plane. Projection of the ascending aorta and the coronary arteries was used to assess the risk of coronary ostia obstruction.

Results

Between January 2014 and October 2014, nine patients underwent aortic ViV procedures in our institution. Among those nine patients, five procedures were retrospectively evaluated as a validation step using the proposed method. The mean (SD) superimposition error was 1.1 (0.75) mm. Subsequently, two live cases were prospectively carried out using our approach, successfully implanting the THV inside the degenerated tissue valve.

Conclusions

Our study demonstrates the feasibility of a computer-guided implantation of THV in ViV procedures. Moreover, it suggests that augmented reality may increase the reliability of THV implantation inside degenerated bioprostheses through better reproducibility.

Frailty in cardiothoracic surgery: systematic review of the literature

A preoperative surgical risk analysis is necessary and important for predicting clinical and surgical outcomes in a clinical setting. Various tools for evaluating the patient characteristics in order to forecast perioperative clinical outcomes have previously been described; however, an objective and precise preoperative risk assessment has not yet been established. In the last decade, the concept of frailty, which is a geriatric assessment that identifies disabilities and weaknesses in patients, has been used in order to predict clinical mortality and morbidity following invasive surgical interventions because the prevalence of elderly patients among those undergoing surgical interventions is increasing. Since there is currently no single generally accepted clinical definition of frailty, many clinical modalities are needed to evaluate the patients' geriatric activity of daily living. Quantifying the quality of frailty is an evolving challenge for predicting surgical risks preoperatively. In recent years, with the development of transcatheter aortic valve implantation (TAVI), this newly definitive preoperative surgical risk assessment tool, frailty, has become more important and is attracting interest in cardiothoracic surgical settings. Thus, this review summarized current consideration on the preoperative risk analysis by frailty as well as future perspectives and the potential of an ideal frailty risk assessment in cardiothoracic surgery, including the management of elderly patients and high-risk aortic valve stenosis by TAVI.

Sutureless aortic valve replacement using a novel autologous tissue heart valve with stent (stent biovalve): proof of concept

We developed an autologous, trileaflet tissue valve ("biovalve") using in-body tissue architecture technology to overcome the disadvantages of current bioprosthetic valves. We designed a novel biovalve with a balloon-expandable stent: the stent biovalve (SBV). This study evaluated the technical feasibility of sutureless aortic valve replacement using the SBV in an orthotopic position, as well as the functionality of the SBV under systemic circulation, in an acute experimental goat model. Three adult goats (54.5-56.1 kg) underwent sutureless AVR under cardiopulmonary bypass (CPB). The technical feasibility and functionality of the SBVs were assessed using angiography, pressure catheterization, and two-dimensional echocardiography. The sutureless AVR was successful in all goats, and all animals could be weaned off CPB. The mean aortic cross-clamp time was 45 min. Angiogram, after weaning the animals off CPB, showed less than mild paravalvular leakage and central leakage was not detected in any of the goats. The mean peak-to-peak pressure gradient was 6.3 ± 5.0 mmHg. Epicardial two-dimensional echocardiograms showed smooth leaflet movement, including adequate closed positions with good coaptation; the open position demonstrated a large orifice area (average aortic valve area 2.4 ± 0.1 cm2). Sutureless AVR, using SBVs, was feasible in a goat model. The early valvular functionalities of the SBV were sufficient; future long-term experiments are needed to evaluate its durability and histological regeneration potential.