Causes and predictors of readmission after transcatheter aortic valve implantation : A meta-analysis and systematic review.

BACKGROUND: Since readmission rate is an important clinical index to determine the quality of inpatient care and hospital performance, the aim of this study was to explain the causes and predictors of readmission following transcatheter aortic valve implantation (TAVI) at short-term and mid-term follow-up. METHODS AND RESULTS: A systematic review and meta-analysis of all published articles from Embase, Pubmed/MEDLINE, and Ovid was carried out. In all, 10 studies including 52,702 patients were identified. The pooled estimate for the overall event rate was 0.15, and cardiovascular causes were the main reason for 30-day readmission (0.42, 95% confidence interval [CI]: 0.39-0.45). In addition, the pooled incidence of 1­year readmission was 0.31, and cardiovascular events were still the main cause (0.41, 95% CI: 0.33-0.48). Patients with major and life-threatening bleeding, new permanent pacemaker implantation, and clinical heart failure were associated with a high risk for early readmission after TAVI. Moreover, an advanced (≥3) New York Heart Association classification, acute kidney injury, paravalvular leak, mitral regurgitation (≥ moderate), and major bleeding predicted unfavorable outcome to 1­year readmission. Female gender and transfemoral TAVI was associated with a lower risk for unplanned rehospitalization. CONCLUSIONS: This meta-analysis found cardiovascular factors to be the main causes for both 30-day and 1­year rehospitalization. Heart failure represented the most common cardiovascular event at both short-term and mid-term follow-up. Several baseline characteristics and procedure-related factors were deemed unfavorable predictors of readmission. Importantly, transfemoral access and female gender were associated with a lower risk of readmission.

Long-Term Durability of Transcatheter Aortic Valve Prostheses in Patients With Bicuspid Versus Tricuspid Aortic Valve.

BACKGROUND: Currently, there is a lack of evidence for the long-term bioprosthetic valve durability of patients with bicuspid aortic valve (BAV) following transcatheter aortic valve replacement (TAVR). METHODS AND RESULTS: This study aimed to evaluate hemodynamic outcome, structural valve deterioration, and bioprosthetic valve failure during long-term follow-up after TAVR in patients with BAV versus patients with tricuspid aortic valve (TAV). Patients with BAV and TAV who underwent TAVR between 2012 and 2020, with echocardiography followed for at least 3 years, were included. Baseline characteristics, long-term valve hemodynamic performance, structural valve deterioration, and bioprosthetic valve failure were compared between patients with BAV and TAV. A total of 170 patients with BAV and 145 patients with TAV were included. The mean duration of follow-up for patients with BAV and TAV was 5.2±1.8 and 5.0±1.7 years. No significant differences were observed in the rates of structural valve deterioration and bioprosthetic valve failure between patients with BAV and TAV: structural valve deterioration, BAV 20 (11.8%) versus TAV 16 (11.0%) at last follow-up (P=0.861); bioprosthetic valve failure, BAV 3 (1.8%) versus TAV 7 (4.8%) at last follow-up (P=0.196). More than moderate intravalvular aortic regurgitation (1.8% versus 4.8%, P=0.196) and paravalvular leak (6.5% versus 3.4%, P=0.305) were rare in both patients with BAV and patients with TAV. CONCLUSIONS: This study indicated satisfactory long-term valve durability of TAVR in patients with BAV. Comparable hemodynamic outcome, structural valve deterioration, and bioprosthetic valve failure could be achieved in patients with BAV and TAV during long-term follow-up after TAVR.

Snaring Self-Expanding Devices to Facilitate Transcatheter Aortic Valve Replacement in Patients with Complex Aortic Anatomies.

The snare-assisted technique has been described to facilitate transcatheter aortic valve replacement (TAVR) delivery system advancement in complex aortic anatomies. However, the evidence is limited to case reports. To evaluate the safety profile of the snare-facilitated approach and its impact on self-expanding (SE) TAVR outcomes, we collected consecutive patients who underwent transfemoral SE-TAVR for aortic stenosis, using propensity score matching (PSM) separately in tricuspid and type-0 and type-1 bicuspid aortic valve morphology between the snare and non-snare groups. In 766 patients, despite the snare group having significantly larger annulus angulation and maximal ascending aortic diameter, both groups achieved comparable 30-day device success rates, regardless of first-generation or new-generation valve use. After PSM, the snare group had a significantly lower new permanent pacemaker implantation rate among 193 type-0 patients (3.3% vs. 18.3%, p = 0.01). The ipsilateral group used new-generation valves less frequently (23.0% vs. 75.4%, p < 0.001), but there were no significant inter-group differences in procedure-related events, except for a lower incidence of PVL ≥ mild in the ipsilateral group (14.9% vs. 32.3%, p = 0.01). In conclusion, the snare-assisted technique appears useful in SE-TAVR with angulated aortic root anatomy, and the benefits were comparable between ipsilateral and contralateral snare techniques.

Outcomes Following Transcatheter Aortic Valve Replacement for Aortic Stenosis in Patients With Type 0 Bicuspid, Type 1 Bicuspid, and Tricuspid Aortic Valves.

BACKGROUND: Data concerning the outcomes of transcatheter aortic valve replacement in type 0 bicuspid aortic stenosis (AS) are scarce. The study aims to compare the outcomes of transcatheter aortic valve replacement for AS in patients with type 0 bicuspid, type 1 bicuspid, and tricuspid aortic valve anatomy. METHODS: We enrolled consecutive patients undergoing transcatheter aortic valve replacement for severe AS between 2012 and 2022 in this single-center retrospective cohort study. The primary outcome was mortality, while secondary outcomes included in-hospital complications such as stroke and pacemaker implantation and transcatheter heart valve hemodynamic performance. RESULTS: The number of patients with AS with type 0 bicuspid, type 1 bicuspid, and tricuspid aortic valve anatomy was 328, 302, and 642, respectively. Self-expanding transcatheter heart valves were used in the majority of patients (n=1160; 91.4%). In the matched population, differences in mortality (30 days: 4.2% versus 1.7% versus 1.7%, Poverall=0.522; 1 year: 10% versus 2.3% versus 6.2%, Poverall=0.099) and all stroke (30 days: 1.0% versus 0.9% versus 0.0%, Poverall=0.765; 1 year: 1.4% versus 1.6% versus 1.3%, Poverall=NS) were nonsignificant, and the incidence of overall in-hospital complications was comparable among groups. Ascending aortic diameter was the single predictor of 1-year mortality in type 0 bicuspid patients (hazard ratio, 1.59 [95% CI, 1.03-2.44]; P=0.035). The proportion of patients with a mean residual gradient ≥20 mm Hg was the highest in those with type 0 bicuspid anatomy, although the need for permanent pacemaker implantation was the lowest in this group. CONCLUSIONS: Major clinical outcomes of transcatheter aortic valve replacement for AS in patients with type 0 bicuspid, type 1 bicuspid, and tricuspid aortic valve anatomy are equivalent at short- and mid-term follow-up. These observations merit further exploration in prospective international registries and randomized controlled trials.

Sex Difference in Outcomes Following Transcatheter Aortic Valve Replacement in Bicuspid Aortic Stenosis.

BACKGROUND: It is unknown whether the sex difference whereby female transcatheter aortic valve replacement (TAVR) candidates had a lower risk profile, a higher incidence of in-hospital complications, but more favorable short- and long-term survival observed in tricuspid cohorts undergoing TAVR would persist in patients with bicuspid aortic valves (BAVs). OBJECTIVES: The aim of this study was to reexamine the impact of sex on outcomes following TAVR in patients with BAVs. METHODS: In this single-center study, patients with BAVs undergoing TAVR for severe aortic stenosis from 2012 to 2021 were retrospectively included. Baseline characteristics, aortic root anatomy, and in-hospital and 1-year valve hemodynamic status and survival were compared between sexes. RESULTS: A total of 510 patients with BAVs were included. At baseline, women presented with fewer comorbidities. Men had a greater proportion of Sievers type 1 BAV, higher calcium volumes (549.2 ± 408.4 mm3 vs 920.8 ± 654.3 mm3; P < 0.001), and larger aortic root structures. Women experienced more vascular complications (12.9% vs 4.9%; P = 0.002) and bleeding (11.1% vs 5.3%; P = 0.019) and higher residual gradients (16.9 ± 7.7 mm Hg vs 13.2 ± 6.4 mm Hg; P < 0.001), while men were more likely to undergo second valve implantations during index TAVR (6.3% vs 15.9%; P = 0.001). Death at 1 year was not significantly different between sexes (HR: 1.15; 95% CI: 0.56-2.35; P = 0.70). Bleeding (adjusted HR: 4.62; 95% CI: 1.51-14.12; P = 0.007) was the single independent predictor of 1-year death for women. CONCLUSIONS: In patients with BAVs undergoing TAVR, women presented with fewer comorbidities, while men had a greater proportion of type 1 BAV, more calcification, and larger aortic roots. In-hospital outcomes favored men, with fewer complications except for the need for second valve implantation, but 1-year survival was comparable between sexes.

Patients With Bicuspid Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement: A Systematic Review and Meta-Analysis.

Objective: We sought to conduct a systematic review and meta-analysis of clinical adverse events in patients undergoing transcatheter aortic valve replacement (TAVR) with bicuspid aortic valve (BAV) vs. tricuspid aortic valve (TAV) anatomy and the efficacy of balloon-expandable (BE) vs. self-expanding (SE) valves in the BAV population. Comparisons aforementioned will be made stratified into early- and new-generation devices. Differences of prosthetic geometry on CT between patients with BAV and TAV were presented. In addition, BAV morphological presentations in included studies were summarized. Method: Observational studies and a randomized controlled trial of patients with BAV undergoing TAVR were included according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Results: A total of 43 studies were included in the final analysis. In patients undergoing TAVR, type 1 BAV was the most common phenotype and type 2 BAV accounted for the least. Significant higher risks of conversion to surgical aortic valve replacement (SAVR), the need of a second valve, a moderate or severe paravalvular leakage (PVL), device failure, acute kidney injury (AKI), and stroke were observed in patients with BAV than in patients with TAV during hospitalization. BAV had a higher risk of new permanent pacemaker implantation (PPI) both at hospitalization and a 30-day follow-up. Risk of 1-year mortality was significantly lower in patients with BAV than that with TAV [odds ratio (OR) = 0.85, 95% CI 0.75-0.97, p = 0.01]. BE transcatheter heart valves (THVs) had higher risks of annular rupture but a lower risk of the need of a second valve and a new PPI than SE THVs. Moreover, BE THV was less expanded and more elliptical in BAV than in TAV. In general, the rates of clinical adverse events were lower in new-generation THVs than in early-generation THVs in both BAV and TAV. Conclusions: Despite higher risks of conversion to SAVR, the need of a second valve, moderate or severe PVL, device failure, AKI, stroke, and new PPI, TAVR seems to be a viable option for selected patients with severe bicuspid aortic stenosis (AS), which demonstrated a potential benefit of 1-year survival, especially among lower surgical risk population using new-generation devices. Larger randomized studies are needed to guide patient selection and verified the durable performance of THVs in the BAV population.

Biological denitrification using corncobs as a carbon source and biofilm carrier.

In this research, agricultural waste--in particular, comcobs--was investigated for use as the sole carbon source and biofilm carrier to remove nitrate from wastewater in up-flow laboratory reactors. An artificial wastewater with a temperature range of 27 to 33 degrees C was used. Fast startup of the reactor and a high nitrate removal efficiency were observed. The highest denitrification rate of 0.203kg/(m3 x d) was achieved when flow rate and nitrate concentration were 153 L/d and 25.3 mgN/L, respectively. The accumulation of nitrite was not observed in this process. Moreover, flow rate and nitrate concentration of the influent were observed to have a significant effect on nitrate removal efficiency. A sharp decline of nitrate removal efficiency was observed when the flow rate was greater than 50 L/d. The reactor had the ability to accommodate a wide range of pH levels (6.5 to 8.5) and dissolved oxygen (1.5 mg/L to 4 mg/L). A time-dependent decrease in nitrate removal efficiency was observed after 67 days of operation. The addition of fresh corncobs brought about a rapid increase of nitrate removal efficiency. Results showed that corncobs could be used as an economical and effective carbon source for denitrification.