Page 13 - Journal of Structural Heart Disease Volume 4, Issue 2

Original Scienti c Article
34
severe symptomatic aortic stenosis who are at an in- termediate or high risk for surgery [2, 3].
Patient selection remains fundamental to achiev- ing successful outcomes with TAVI. A key step in the selection process is systematic anatomical work-up from access site to implantation site using multi-mo- dality imaging. The most important aspect of ana- tomical screening involves assessment of the aortic valvular complex and the peripheral arterial vascu- lature, allowing identi cation of the optimal pros- thesis size and the most appropriate access route. In the elective setting, multi-slice computed tomogra- phy (MSCT) of the aortic valve complex, aorta, and iliofemoral vessels is the gold standard assessment [4]. General anesthesia (GA) is usually required when transesophageal echocardiography (TEE) is used, both for the comfort of the patient and to maintain a secure airway [5].
However, patients with severe aortic stenosis may present as urgent or emergency cases and be unable to undergo standard investigations due to clinical instability or renal dysfunction. Balloon aortic valvu- loplasty “bridging” to TAVI may be used but is not low- risk in this setting [6]. The use of emergency TAVI is increasing [7-11].
During the early use of TAVI, computed tomogra- phy (CT) pre-assessment was not routine. We used retrospective data to analyze whether a minimalist approach to TAVI, with minimal use of CT, TEE, and GA, could yield reasonable TAVI outcomes and thus whether this approach could be appropriately used in urgent or emergency settings as “primary” TAVI.
Materials and Methods
Patient Population
The study population comprised 384 consecutive patients from two high-volume centers (Brighton and Belfast) in the United Kingdom over a 5-year period (2007–2012). Patients were assessed using iliofemoral angiography and TTE. MSCT or TEE was used in only a minority of cases during this period. Valve sizing was based on a combination of TTE annular measure- ments (which provide an anteroposterior measure- ment) and the aortogram (which provides a lateral measurement). The optimal implant was derived from aortography starting in the anterior-posterior/
caudal 15° projection, adjusting according to the ini- tial image. A self-expanding CoreValve prosthesis was used in most cases, and the degree of oversizing was at the discretion of the operators.
All TAVI case data were entered prospectively into local dedicated databases based on a predetermined dataset agreed upon by the Society for Cardiothorac- ic Surgery in Great Britain and Ireland and the British Cardiovascular Intervention Society. This included in- formation on patient demographics, risk factors, and outcome measures. Data consistency was assured by internal audit undertaken independently. Peri-pro- cedural and post-procedural complications were re- ported according to de nitions de ned within the national dataset at the time [5]. All data were cross- checked prior to uploading to the Central Cardiac Au- dit Database. Mortality tracking was obtained via the Medical Research Information Service for the English cohort and via the General Register O ce of North- ern Ireland for the Northern Irish cohort. Mortality tracking was successful in 100% of cases.
Endpoints
The primary endpoint of the study was all-cause mortality assessed at 30 days and 1 year. The second- ary endpoint was in-hospital major adverse cardio- vascular events (MACE), de ned as a composite of in-hospital death, myocardial infarction, and stroke.
De nitions
Device success was de ned as implantation of a single functioning prosthetic valve within the aor- tic annulus, with stable hemodynamics, absence of severe paravalvular aortic regurgitation, and no peri-procedural mortality or conversion to emergen- cy open valve surgery. Safety and e cacy endpoints were de ned using Valve Academic Research Consor- tium (VARC) de nitions [7].
Statistical Analysis
Categorical data are presented as percentages, and comparisons between groups were performed using Chi-square tests. Continuous data are present- ed as mean ± standard deviation (SD) or median (in- terquartile range), and comparisons between groups were performed with two-sample t-tests. Time-to- event data analysis was performed using Cox propor-
Journal of Structural Heart Disease, April 2018
Volume 4, Issue 2:33-41