Prediction of bleeding events in patients with venous thromboembolism on stable anticoagulation treatment.

Attempts at identifying patients with an elevated risk of bleeding while on anticoagulation following acute venous thromboembolism (VTE) have largely been unsuccessful thus far. We sought to develop a clinical prediction score for bleeding during stable anticoagulation treatment after acute VTE.We performed a post hoc analysis of the pooled RE-COVER studies, two double-blind randomised "sister" trials evaluating dabigatran versus standard treatment in 5107 VTE patients.A score was derived from patients randomised to dabigatran using logistic regression analysis covering the complete follow-up period. The final model, named VTE-BLEED, included six variables and yielded a c-statistic of 0.72 (95% CI 0.67-0.76). Patients from the derivation cohort in the low-risk group (<2 points; 74% of the derivation population) had a bleeding incidence of 2.8% compared to 12.6% in the elevated-risk group (OR 5.0; 95% CI 3.5-7.1). The score proved accurate for our primary end-point, i.e. prediction of major bleeding after day 30 ("stable" anticoagulation), both in patients on dabigatran (c-statistic 0.75, 95% CI 0.61-0.89) and those on warfarin (0.78, 95% CI 0.68-0.86; p=0.77 for difference).The new VTE-BLEED score accurately predicted major bleeding events in VTE patients on stable anticoagulation with both dabigatran and warfarin.

Improving the prediction of virological response to tipranavir: the development and validation of a tipranavir-weighted mutation score.

BACKGROUND: The purpose of this study was to develop a tipranavir-weighted mutation score that provides guidance to treating physicians on the relative effect of specific protease mutations on tipranavir activity. METHODS: Weights were developed using data from RESIST tipranavir-treated patients based on regressions of virological response at weeks 8 and 24, accounting for baseline CD4(+) T-cell count and background regimen activity. The resulting weighted score and cutoffs were validated using a set of cohort patients external to the tipranavir development programme. Response rates were tabulated for the new weighted score and compared with other tipranavir mutation scores used in clinical practice. RESULTS: The final weights were 74P, 82L/T, 83D and 47V (+4), 58E and 84V (+3), 36I, 43T and 54A/M/V (+2), 10V, 33F and 46L (+1), 24I and 76V (-2), 50L/V (-4), and 54L (-6). Tipranavir-weighted score susceptibility categories were susceptible ≤3, partially susceptible >3 but ≤10, and resistant ≥11. Week 48 response rates for RESIST patients were 34.6%, 15.9% and 5.9%, respectively. Using the external cohort data (n=150), the weighted score was highly associated with week 8 viral load reduction (P=0.0027). Only one other score achieved statistical significance. CONCLUSIONS: The tipranavir-weighted score developed and externally validated here, in three datasets representing a broad population of treatment-experienced patients, can be used to make clinical decisions about whether to consider tipranavir in a treatment-experienced patient who has limited treatment options.