Transcatheter Aortic Valve Replacement Optimization Strategies: Cusp Overlap, Commissural Alignment, Sizing, and Positioning

As transcatheter aortic valve replacement (TAVR) rapidly expands to younger patients and those at low surgical risk, there is a compelling need to identify patients at increased risk of post-procedural complications, such as paravalvular leak, prosthesis–patient mismatch, and conduction abnormalities. This review highlights the incidence and risk factors of these procedural complications, and focuses on novel methods to reduce them by using newer generation transcatheter heart valves and the innovative cusp-overlap technique, which provides optimal fluoroscopic imaging projection to allow for precise implantation depth which minimizes interaction with the conduction system. Preserving coronary access after TAVR is another important consideration in younger patients. This paper reviews the significance of commissural alignment to allow coronary cannulation after TAVR and discusses recently published data on modified delivery techniques to improve commissural alignment

TCT-669 Very Low Intravenous Contrast Dose (20 cc) Computed Tomographic Angiography Protocol for Pre-Procedural Assessment of the Aortic Annulus Prior to Transcatheter Aortic Valve Replacement: Validation by 3-Dimensional Transesophageal Echocardiography

Von Dr. Fr. Dietric

Carotid Embolectomy in the Treatment of a Paradoxical Embolus

Development of a paradoxical embolus to the carotid circulation through a patent foramen ovale is uncommon but well documented. Previous surgical experience with this entity is limited. Treatment for this condition typically involves anticoagulation or the use of an inferior vena cava filter with concurrent closure of the patent foramen itself. We report successful surgical treatment of a woman with a paradoxical embolus lodged in her left carotid artery. In addition, we provide a brief review of this rare topic and treatment rationale.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41366/1/10016_2003_Article_13.pd

Markov model for selection of aortic valve replacement versus transcatheter aortic valve implantation (without replacement) in high-risk patients

Comparisons between transcatheter aortic valve implantation without replacement (TAVI) and tissue aortic valve replacement (AVR) in clinical trials might not reflect the outcomes in standard clinical practice. This could have important implications for the relative cost-effectiveness of these alternatives for management of severe aortic stenosis in high-risk patients for whom surgery is an option. The mean and variance of risks, transition probabilities, utilities, and cost of TAVI, AVR, and medical management derived from observational studies were entered into a Markov model that examined the progression of patients between relevant health states. The outcomes and cost were derived from 10,000 simulations. Sensitivity analyses were based on variations in the likelihood of mortality, stroke, and other commonly observed outcomes. Both TAVI and AVR were cost-effective compared to medical management. In the reference case (age 80 years, the perioperative TAVI and AVR mortality was 6.9% vs 9.8%, and annual mortality was 21% vs 24%), the utility of TAVI was greater than that of AVR (1.78 vs 1.72 quality-adjusted life years) and the lifetime cost of TAVI exceeded that of AVR ($59,503 vs$56,339). The incremental cost-effectiveness ratio was $52,773/quality-adjusted life years. Threshold analyses showed that variation in the probabilities of perioperative and annual mortality after AVR and after TAVI and annual stroke after TAVI were important determinants of the favored strategy. Sensitivity analyses defined the thresholds at which TAVI or AVR was the preferred strategy with regard to health outcomes and cost. In conclusion, TAVI satisfies current metrics of cost-effectiveness relative to AVR and might provide net health benefits at acceptable cost for selected high-risk patients among whom AVR is the current procedure of choice

Systematic review of the cost-effectiveness of transcatheter aortic valve implantation

OBJECTIVE: Transcatheter aortic valve implantation (TAVI) has emerged as an alternative treatment to aortic valve replacement (AVR) for selected patients with severe aortic stenosis. The present systematic review was conducted to analyze the cost-effectiveness of this novel technique within reimbursed healthcare systems. METHODS: Two reviewers used 7 electronic databases from January 2000 to November 2012 to identify relevant cost-effectiveness studies of TAVI versus AVR or medical therapy. The primary endpoints were the incremental cost-effectiveness ratio (ICER) and the probability of cost-effectiveness. The eligible studies for the present systematic review included those in which the cost-effectiveness data were measured or projected for TAVI and either medical therapy or AVR. All forms of TAVI were included, and all retrieved publications were limited to the English language. RESULTS: Eight studies were included for quantitative assessment. The ICER for TAVI compared with medical therapy for surgically inoperable patients ranged from US$26,302 to US$61,889 per quality-adjusted life year gained. The probability of TAVI being cost-effective compared with medical therapy ranged from 0.03 to 1.00. The ICER values for TAVI compared with AVR for high-risk surgical candidates ranged from US$32,000 to US$975,697 per quality-adjusted life year gained. The probability of TAVI being cost-effective in this cohort ranged from 0.116 to 0.709. CONCLUSIONS: Depending on the ICER threshold selected, TAVI is potentially justified on both medical and economic grounds compared with medical therapy for patients deemed to be surgically inoperable. However, in the high-risk surgical patient cohort, the evidence is currently insufficient to economically justify the use of TAVI in preference to AVR.6 page(s

Cross-talk between calpain and caspase proteolytic systems during neuronal apoptosis

Cross-talk between calpain and caspase proteolytic systems has complicated efforts to determine their distinct roles in apoptotic cell death. This study examined the effect of overexpressing calpastatin, the specific endogenous calpain inhibitor, on the activity of the two proteolytic systems following an apoptotic stimulus. Human SH-SY5Y neuroblastoma cells were stably transfected with full-length human calpastatin cDNA resulting in 20-fold overexpression based on Western blot and 5-fold greater calpain inhibitory activity in cell extracts. Wild type and calpastatin overexpressing (CST1) cells were neuronally differentiated and apoptosis-induced with staurosporine (0.1-1.0 µm). Calpastatin overexpression decreased calpain activation, increased caspase-3-like activity, and accelerated the appearance of apoptotic nuclear morphology. Following 0.1-0.2 µm staurosporine, plasma membrane integrity based on calcein-acetoxymethyl fluorescence was significantly greater at 24 h in differentiated CST1 compared with differentiated wild type cells. However, this protective effect was lost at higher staurosporine doses (0.5-1.0 µm), which resulted in pronounced caspase-mediated degradation of the overexpressed calpastatin. These results suggest a dual role for calpains during neuronal apoptosis. In the early execution phase, calpain down-regulates caspase-3-like activity and slows progression of apoptotic nuclear morphology. Subsequent calpain activity, facilitated by caspase-mediated degradation of calpastatin, contributes to plasma membrane disruption and secondary necrosis.Journal ArticleFinal article publishe