Aims:The indication for transcatheter aortic valve implantation (TAVI) has evolved from inoperable patients to patients at increased surgical risk.In low-risk patients, surgical aortic valve replacement (SAVR) remains the standard of care.The aim of this study was to explore the outcomes of TAVI and SAVR in patients with a Society of Thoracic Surgeons (STS) predicted risk of mortality (PROM) score below 3% in the SURTAVI trial. Methods and results:In SURTAVI, patients at intermediate surgical risk based on Heart Team consensus were randomised to TAVI or SAVR.We stratified the overall patient population into quintiles based on the STS PROM score; the one-year mortality was correlated with the mean STS PROM score in each quintile.The quintiles were regrouped into three clinically relevant categories of STS score: less than 3%, 3 to <5%, and >5%.All-cause mortality or disabling stroke in each risk stratum was compared between TAVI and SAVR.Linear regressions between mean values of STS PROM in each quintile and observed allcause mortality at one year showed great association for the global population (r 2 =0.92),TAVI (r 2 =0.89) and SAVR cohorts (r 2 = 0.73).All-cause mortality or disabling stroke of TAVI vs. SAVR was 1.5% vs. 6.5% (p=0.04),6.5% vs. 7.6% (p=0.52) and 13.5% vs. 11.0%(p=0.40) in the <3%, 3-5%, and ≥5% STS score strata, respectively.Conclusions: Among patients at intermediate surgical risk but with an STS PROM <3%, TAVI may achieve superior clinical outcomes compared to SAVR.These findings support the need for an adequately powered randomised trial to compare TAVI with SAVR in patients at low operative risk.
ABSTRACT A test program on concrete‐filled double skin tubular (CFDST) beams with austenitic stainless steel outer tubes and high strength steel inner tubes is presented in this paper. A total of 22 four‐point bending tests was carried out to study the behaviour and strengths of CFDST beams. The stainless steel outer tubes were circular hollow sections (CHS) with average diameter‐to‐thickness ratios of 56.8 and 48.5, and the measured 0.2% proof strengths of 276 MPa and 300 MPa, respectively. The high strength steel inner tubes were also circular hollow sections (CHS) with diameter‐to‐thickness ratios ranging from 5.0 to 22.8, and corresponding measured 0.2% proof stress ranging from 433 to 1029 MPa. The annuli were filled with concrete with three different concrete cylinder strengths of 40, 80 and 120 MPa. The moment capacities, moment–curvature relationships and failure modes of the beams are reported in this paper. It should be noted that currently there are no design provisions for concrete‐filled stainless steel members. The test strengths were therefore compared with the moment capacity predictions in existing design codes (the European Code and American Specification) for concrete‐filled carbon steel tubes. The comparisons revealed that both design codes provide very conservative resistance predictions.
No abstract is provided for this article.
A double blind study of 44 patients (24 placebo, 20 cimetidine) was undertaken to determine tha effect of cimetidine on the pH and volume of gastric fluid during anaesthesia. The pH was significantly higher on cimetidine-treated patients than placebo-treated patients at 0, 15, 30 and 45 minutes following intubation. At induction of anaesthesia, mean pH on cimetidine was 4.5 and on placebo mean H was 2.0. Approximately 70% of patients on cimetidine and 20% on placebo recorded a pH above 2.5 during anaesthesia. The reason for a pH recording of less than 2.5 in seven patients on cimetidine could not be ascertained. Mean volume of gastric aspirate was slightly lower in the cimetidine group at 0, 15, 30 and 45 minutes, but the differences were not significant.