Journal Article

Novel United Kingdom prognostic model for 30-day mortality following transcatheter aortic valve implantation

Ludman, Peter F, Townend, Jonathan N, de Belder, Mark A, Redwood, Simon R, Sperrin, Matthew, Buchan, Iain, Gunning, Mark, Moat, Neil E, Mamas, Mamas A, Martin, Glen P, Banning, Adrian P

2018

Overview

ObjectiveExisting clinical prediction models (CPM) for short-term mortality after transcatheter aortic valve implantation (TAVI) have limited applicability in the UK due to moderate predictive performance and inconsistent recording practices across registries. The aim of this study was to derive a UK-TAVI CPM to predict 30-day mortality risk for benchmarking purposes.MethodsA two-step modelling strategy was undertaken: first, data from the UK-TAVI Registry between 2009 and 2014 were used to develop a multivariable logistic regression CPM using backwards stepwise regression. Second, model-updating techniques were applied using the 2013–2014 data, thereby leveraging new approaches to include frailty and to ensure the model was reflective of contemporary practice. Internal validation was performed by bootstrapping to estimate in-sample optimism-corrected performance.ResultsBetween 2009 and 2014, up to 6339 patients were included across 34 centres in the UK-TAVI Registry (mean age, 81.3; 2927 female (46.2%)). The observed 30-day mortality rate was 5.14%. The final UK-TAVI CPM included 15 risk factors, which included two variables associated with frailty. After correction for in-sample optimism, the model was well calibrated, with a calibration intercept of 0.02 (95% CI −0.17 to 0.20) and calibration slope of 0.79 (95% CI 0.55 to 1.03). The area under the receiver operating characteristic curve, after adjustment for in-sample optimism, was 0.66.ConclusionThe UK-TAVI CPM demonstrated strong calibration and moderate discrimination in UK-TAVI patients. This model shows potential for benchmarking, but even the inclusion of frailty did not overcome the need for more wide-ranging data and other outcomes might usefully be explored.

• Publisher: BMJ Publishing Group LTD,BMJ Publishing Group
• Subject: Activities of daily living / Adult / Aged / Aged, 80 and over / Aortic Valve Stenosis - diagnosis / Aortic Valve Stenosis - mortality / Aortic Valve Stenosis - surgery / Benchmarking / Datasets / Decision Support Techniques / Female / Frailty / Heart surgery / Humans / Male / Medical prognosis / Middle Aged / Mortality / Patients / Predictive Value of Tests / Quality Indicators, Health Care / Registries / Reproducibility of Results / Risk Assessment / Risk Factors / Time Factors / Transcatheter Aortic Valve Replacement - adverse effects / Transcatheter Aortic Valve Replacement - mortality / Transcatheter Aortic Valve Replacement - standards / Treatment Outcome / United Kingdom / Valvular Heart Disease / Variables