TAVR Vs. SAVR in Intermediate-Risk Patients: What Influences Our Choice of Therapy

The influence of lipoprotein(a) on aortic valve calcification in patients undergoing transcatheter aortic valve replacement

BACKGROUND

Elevated levels of lipoprotein(a) (Lp[a]) have been recognized as substantial risk factors for cardiovascular disease and aortic stenosis (AS). However, the specific role of Lp(a) in promoting aortic valve calcification (AVC) and influencing mortality in elderly, multimorbid patients undergoing transcatheter aortic valve replacement (TAVR) remains unclear and warrants further investigation.

METHODS

A retrospective analysis was conducted on all consecutive patients who underwent TAVR between August 2019 and June 2020 at our clinic. Patients with missing data or prior aortic valve replacement were excluded. The study cohort was stratified based on an Lp(a) threshold of 60 mg/dl according to guidelines for lipoprotein apheresis in UK and Germany.1,2 RESULTS: In total, 454 patients were included into the analysis. Mean age was 81 ± 6 years and patients presented with a notable cardiovascular risk profile. Lp(a) values ≥ 60 mg/dl were detected in 102 (22.5%) patients, while 352 (77.5%) had Lp(a) values < 60 mg/dl. The median calcium volume of the total cohort was 894.5 [570.8; 1,382.8] mm2. No significant difference was observed between the groups (p = 0.83). Furthermore, Lp(a) did not emerge as a statistically significant predictor of calcium levels before TAVR. Notably, male gender (B = 404.11, p < 0.001) and mean trans-valvular pressure gradient (B = 15.64, p < 0.001) were identified as the strongest coefficients within the robust regression analysis. Log-rank tests indicated no prognostic utility of Lp(a) for 30-day all-cause mortality (p = 0.30) or 40 months long-term all-cause mortality (p = 0.60).

CONCLUSION

Lp(a) might not exert a significant effect on calcification levels or all-cause mortality in patients undergoing TAVR. Despite the study's highly selected population, these results align with current research, supporting the assumption that the influence of Lp(a) may be confined to the early stages of AS and its progression.

Multimodal preoperative imaging for transcatheter mitral valve replacement in the domestic sheep model

Preclinical in vivo evaluation is an essential step in the progression of new cardiac devices into patient use, with studies predominantly performed in the domestic sheep model. A growing area of interest in cardiac device development is transcatheter mitral valve replacement (TMVR). Clinically, multimodal imaging, or computed tomography (CT) and echocardiography (echo) are used extensively to preoperatively determine mitral valve morphology prior to an intervention, but there is no description on how these modalities can be implemented to support preclinical studies. The purpose of this study is to apply clinically relevant CT and echo acquisition and assessment techniques to a large group of naive research sheep in order to analyze and report modality-related effects on mitral valve dimensional reference intervals in the sheep model. To this end, fifty-five adult domestic sheep underwent preoperative CT and echo exams and resultant images were analyzed using a landmark-based multiplanar measurement protocol and compiled into a master dataset for statistical analysis. We found moderate agreement between CT and echo-derived measurements of the mitral valve in sheep and propose the first clinically-relevant dimensional indices for the sheep's naive mitral valve which can be used to guide future studies evaluating novel TMVR devices. This study is the first of its kind in proposing a reproducible method for detailed examination of the mitral valve in the sheep model using clinically-relevant multimodal imaging. As in patients, CT and echo can reveal accurate native mitral valve dimensions in the sheep prior to preclinical TMVR studies.

A Review of the Cost Effectiveness of Transcatheter Aortic Valve Replacement (TAVR) Versus Surgical Aortic Valve Replacement (SAVR)

The cost of transcatheter aortic valve replacement (TAVR) has been studied in the context of high-risk or specific comorbidity populations; this paper provides a comprehensive overview of broader patient populations' outcomes and costs with TAVR in comparison to surgical aortic valve replacement (SAVR). In the past, SAVR had been the more cost-effective option than TAVR, but in recent years, TAVR has been becoming more cost-effective.Though the cost of TAVR can vary due to several factors the major focus of this review will focus on the surgical technique, medicare reimbursements, insertion point, and varying risk populations. In conclusion, the price of TAVR is declining as more cost-efficient valves arrive on the market. Climbing healthcare costs play a significant role in clinical decisions when deciding on which procedures are most cost-effective for the patient and healthcare system. The declining price of TAVR could lead to the preference of TAVR over SAVR for both low-risk and high-risk aortic stenosis patients.

Inspiratory Muscle and Functional Performance of Patients Entering Cardiac Rehabilitation after Cardiac Valve Replacement

Limited research has examined inspiratory muscle performance (IMP) and functional performance (FP) of patients after valve replacement surgery (VRS). The purpose of this study was to examine IMP as well as several measures of FP in patients post-VRS. The study results of 27 patients revealed that patients undergoing transcatheter VRS were significantly (p = 0.01) older than patients undergoing minimally invasive or median sternotomy VRS with the median sternotomy VRS group performing significantly (p < 0.05) better than the transcatheter VRS group in the 6-min walk test, 5x sit-to-stand test, and sustained maximal inspiratory pressure. The 6-min walk test and IMP measures in all groups were significantly (p < 0.001) lower than predicted values. Significant (p < 0.05) relationships were found between IMP and FP with greater IMP being associated with greater FP. Pre-operative and early post-operative rehabilitation may improve IMP and FP post-VRS.

Preoperative cognition predicts clinical stroke/TIA and mortality after surgical aortic valve replacement in older adults

Stroke and death remain risks of surgical aortic valve replacement (SAVR). Preoperative cognitive screeners repeatedly show that reduced scores predict postoperative outcome, but less is known about comprehensive neuropsychological measures predicting risk. This study had two aims: 1) investigate whether preoperative cognitive measures predicted postoperative clinical stroke/transient ischemic attack (TIA) and mortality in older adults undergoing SAVR, and 2) identify the best predictors within a comprehensive cognitive protocol. A total of 165 participants aged 65 + with moderate-to-severe aortic stenosis completed a comprehensive cognitive test battery preoperatively. Postoperative stroke evaluations were conducted by trained stroke neurologists preoperatively and postoperatively, and mortality outcomes were obtained by report and records. Logistic regressions were conducted to evaluate preoperative cognitive predictors of clinical stroke/TIA within 1 week of surgery and mortality within 1 year of surgery. Multivariate models showed measures of delayed verbal memory recall (OR = 0.86; 95% CI 0.74-0.99) and visuospatial skills (OR = 0.95; 95% CI 0.90-1.01) predicted clinical stroke/TIA within 1 week of surgery, R2 = .41, p < .001, ƒ2 = .69. Measures of naming ability (OR = 0.88; 95% CI 0.80-0.96), verbal memory recall (OR = 1.23; 95% CI 0.99-1.51), visual memory recall (OR = 0.90; 95% CI 0.80-1.00), medical comorbidities (OR = 1.71; 95% CI 1.22-2.65), and sex (OR = 2.39; 95% CI 0.90-7.04) were significant predictors of death within 1 year of surgery, R2 = .68, p < .001, ƒ2 = 2.12. Preoperative cognitive measures reflecting temporal and parietal lobe functions predicted postoperative clinical stroke/TIA within 1 week of SAVR and mortality within 1 year of SAVR. As such, cognitive measures may offer objective and timely indicators of preoperative health, specifically vulnerabilities in cerebral hypoperfusion, which may inform intervention and/or intensive postoperative monitoring and follow-up after SAVR.

Biomechanics of Transcatheter Aortic Valve Implant

Transcatheter aortic valve implantation (TAVI) has grown exponentially within the cardiology and cardiac surgical spheres. It has now become a routine approach for treating aortic stenosis. Several concerns have been raised about TAVI in comparison to conventional surgical aortic valve replacement (SAVR). The primary concerns regard the longevity of the valves. Several factors have been identified which may predict poor outcomes following TAVI. To this end, the lesser-used finite element analysis (FEA) was used to quantify the properties of calcifications which affect TAVI valves. This method can also be used in conjunction with other integrated software to ascertain the functionality of these valves. Other imaging modalities such as multi-detector row computed tomography (MDCT) are now widely available, which can accurately size aortic valve annuli. This may help reduce the incidence of paravalvular leaks and regurgitation which may necessitate further intervention. Structural valve degeneration (SVD) remains a key factor, with varying results from current studies. The true incidence of SVD in TAVI compared to SAVR remains unclear due to the lack of long-term data. It is now widely accepted that both are part of the armamentarium and are not mutually exclusive. Decision making in terms of appropriate interventions should be undertaken via shared decision making involving heart teams.

Patient-specific simulation of transcatheter aortic valve replacement: impact of deployment options on paravalvular leakage

Transcatheter aortic valve replacement (TAVR) has emerged as an effective alternative to conventional surgical valve replacement in high-risk patients afflicted by severe aortic stenosis. Despite newer-generation devices enhancements, post-procedural complications such as paravalvular leakage (PVL) and related thromboembolic events have been hindering TAVR expansion into lower-risk patients. Computational methods can be used to build and simulate patient-specific deployment of transcatheter aortic valves (TAVs) and help predict the occurrence and degree of PVL. In this study finite element analysis and computational fluid dynamics were used to investigate the influence of procedural parameters on post-deployment hemodynamics on three retrospective clinical cases affected by PVL. Specifically, TAV implantation depth and balloon inflation volume effects on stent anchorage, degree of paravalvular regurgitation and thrombogenic potential were analyzed for cases in which Edwards SAPIEN and Medtronic CoreValve were employed. CFD results were in good agreement with corresponding echocardiography data measured in patients in terms of the PVL jets locations and overall PVL degree. Furthermore, parametric analyses demonstrated that positioning and balloon over-expansion may have a direct impact on the post-deployment TAVR performance, achieving as high as 47% in PVL volume reduction. While the model predicted very well clinical data, further validation on a larger cohort of patients is needed to verify the level of the model's predictions in various patient-specific conditions. This study demonstrated that rigorous and realistic patient-specific numerical models could potentially serve as a valuable tool to assist physicians in pre-operative TAVR planning and TAV selection to ultimately reduce the risk of clinical complications.