Impact of aortic annular size and valve type on haemodynamics and clinical outcomes after transcatheter aortic valve implantation.

INTRODUCTION: Data on patients with small aortic annuli (SAA) undergoing transcatheter aortic valve implantation (TAVI) are limited. We aim to describe the impact of aortic annular size, particularly SAA and TAVI valve type on valve haemodynamics, durability and clinical outcomes. METHOD: All patients in National Heart Centre Singapore who underwent transfemoral TAVI for severe symptomatic native aortic stenosis from July 2012 to December 2019 were included. Outcome measures include valve haemodynamics, prosthesis-patient mismatch (PPM), structural valve degeneration (SVD) and mortality. RESULTS: A total of 244 patients were included. The mean Society of Thoracic Surgeons score was 6.22±6.08, with 52.5% patients with small aortic annulus (<23mm), 33.2% patients with medium aortic annulus (23-26mm) and 14.3% patients with large aortic annulus (>26mm). There were more patients with self-expanding valve (SEV) (65.2%) versus balloon-expandable valve (BEV) (34.8%). There were no significant differences in indexed aortic valve area (iAVA), mean pressure gradient (MPG), PPM, SVD or mortality across all aortic annular sizes. However, specific to the SAA group, patients with SEV had larger iAVA (SEV 1.19±0.35cm2/m2 vs BEV 0.88±0.15cm2/m2, P<0.01) and lower MPG (SEV 9.25±4.88 mmHg vs BEV 14.17±4.75 mmHg, P<0.01) at 1 year, without differences in PPM or mortality. Aortic annular size, TAVI valve type and PPM did not predict overall mortality up to 7 years. There was no significant difference in SVD between aortic annular sizes up to 5 years. CONCLUSION: Valve haemodynamics and durability were similar across the different aortic annular sizes. In the SAA group, SEV had better haemodynamics than BEV at 1 year, but no differences in PPM or mortality. There were no significant differences in mortality between aortic annular sizes, TAVI valve types or PPM.

Clinical Updates on the Diagnosis and Management of Chronic Thromboembolic Pulmonary Hypertension.

INTRODUCTION: Chronic thromboembolic pulmonary hypertension (CTEPH) is a known sequela after acute pulmonary embolism (PE). It is a debilitating disease, and potentially fatal if left untreated. This review provides a clinically relevant overview of the disease and discusses the usefulness and limitations of the various investigational and treatment options. METHODS: A PubMed search on articles relevant to PE, pulmonary hypertension, CTEPH, pulmonary endarterectomy, and balloon pulmonary angioplasty were performed. A total of 68 articles were found to be relevant and were reviewed. RESULTS: CTEPH occurs as a result of non-resolution of thrombotic material, with subsequent fibrosis and scarring of the pulmonary arteries. Risk factors have been identified, but the underlying mechanisms have yet to be fully elucidated. The cardinal symptom of CTEPH is dyspnoea on exertion, but the diagnosis is often challenging due to lack of awareness. The ventilation/perfusion scan is recommended for screening for CTEPH, with other modalities (eg. dual energy computed tomography pulmonary angiography) also being utilised in expert centres. Conventional pulmonary angiography with right heart catheterisation is important in the final diagnosis of CTEPH. CONCLUSION: Operability assessment by a multidisciplinary team is crucial for the management of CTEPH, as pulmonary endarterectomy (PEA) remains the guideline recommended treatment and has the best chance of cure. For inoperable patients or those with residual disease post-PEA, medical therapy or balloon pulmonary angioplasty are potential treatment options.

Retrospective review of arteriovenous fistula success rate in a multi-ethnic Asian population.

BACKGROUND: Native vein arteriovenous fistulas (AVFs) are the recommended first-line vascular access in hemodialysis patients. Despite this, AVFs are plagued with unfavorable maturation rates. We conducted a retrospective cohort study to assess the AVF success rate and to identify any significant associating factors. METHODOLOGY: Demographic and clinical data of all AVFs created from January 2011 to June 2013 at a single center with a multi-ethnic Asian population, were reviewed. The primary outcome was AVF successfully used for hemodialysis (FUSH) at 6 months. Secondary endpoints were the overall FUSH and actual maturation time of the AVFs. Univariate and multivariate analyses were performed to identify factors associated with AVF success. RESULTS: A total of 375 fistulas were created during the study period (110 radiocephalic, 176 brachiocephalic, 89 brachiobasilic). The mean age was 59.4 ± 12.6 years and 42.9% were females. Seventy-one percent of patients had diabetes, 32.5% had ischemic heart disease and 10.7% had peripheral vascular disease. 246/375 (65.6%) AVFs FUSH by 6 months, and the average AVF maturation time was 16.1 ± 10.7 weeks. Of the 246 AVFs, 11% required secondary procedure to assist their success. Univariate analysis showed that gender (p = 0.035), age (p = 0.018), vein size on pre-operative vein mapping (p = 0.004) and operating surgeon (p = 0.021) were significant factors associated with AVF success. On multivariate analysis, age, pre-operative vein size and operating surgeon were significantly associated with fistula success. CONCLUSIONS: Reasonable FUSH rates can be achieved in the study patients. Patient age, pre-operative vein mapping size and operating surgeon were shown to influence AVF success rate.