Failure of the Ottawa Score to Predict the Risk of Recurrent Venous Thromboembolism in Cancer Patients: The Prospective PREDICARE Cohort Study

Abstract

Introduction: Recurrent venous thromboembolism (VTE) despite curative anticoagulation is frequent in patients with cancer. Identifying patients with a high risk of recurrence could have therapeutic implications. A prospective study was designed to validate the Ottawa risk score of recurrent VTE in cancer patients. Methods: In a prospective multicenter observational cohort, adult cancer patients with a recent diagnosis of symptomatic or incidental lower limb deep vein thrombosis or pulmonary embolism were treated with tinzaparin for 6 months. The primary endpoint was the recurrence of symptomatic or asymptomatic VTE within the first 6 months of treatment. All clinical events were centrally reviewed and adjudicated. Time-to-event outcomes were estimated by the Kalbfleisch and Prentice method to take into account the competing risk of death. A C-statistic value >0.70 was needed to validate the Ottawa score. Results: A total of 409 patients were included and analyzed on an intention-to-treat basis. Median age was 68 years, 60.4% of patients had PE, VTE was symptomatic in 271 patients (66.3%). The main primary sites were lung (31.3%), digestive tract (18.3%) and breast (13.9%) cancers. The Ottawa score was high (≥1) in 58% of patients. The 6-month cumulative incidence of recurrent VTE was 7.3% (95% confidence interval [CI]: 4.9-11.1) overall, and 5.0% (95%CI: 2.3-10.8) vs 9.1% (95%CI: 6.1-13.6) in the Ottawa low vs high risk groups, respectively. The C-statistic value was 0.60 (95%CI: 0.55-0.65). Conclusion: In this prospective cohort of patients with cancer receiving tinzaparin for VTE, the Ottawa score failed to accurately predict recurrent VTE.

The Ottawa Score Performs Poorly to Identify Cancer Patients at High Risk of Recurrent Venous Thromboembolism: Insights from the TROPIQUE Study and Updated Meta-Analysis

“…The Ottawa score is currently the only RAM available for predicting the risk of VTE recurrence in cancer patients. Developed by Louzada et al, in 2012 [15], this score has been assessed in several external validation studies with conflicting results [17,18,[23][24][25]. Applying the Ottawa score to cancer patients enrolled in the prospective TROPIQUE study who were treated with LMWHs for a confirmed index VTE failed to identify accurately those who developed recurrent VTE within 6 months, as reflected by an AUROC of 0.53 and an accuracy of 57.9%.…”

“…Patients with a high-risk Ottawa score (49.3%) had a 6-month pooled crude rate of recurrent VTE of 18.6% (95% CI 13.9-23.9) compared to 7.4% (95%CI 3.4-12.5) for those with a low-risk Ottawa score [16]. However, this score failed to identify patients at high risk of recurrent VTE in two recent large prospective studies [17,18], thereby questioning its reliability.…”

“…Sixteen records were duplicates; 78 were excluded after title and abstract screening; and 12 were assessed for eligibility (Supplementary Figure S2). Six studies meeting the inclusion criteria [15,17,18,[23][24][25] were added to the present post-hoc analysis of the TROPIQUE study resulting in a pooled analysis of 3413 patients (Supplementary Table S2). Patients with a high-risk Ottawa score (46.7%) had a pooled 6-month rate of recurrent VTE of 13.2% (95% CI 8.5-18.7%; I 2 = 89%; p < 0.001, Figure 3) versus 6.8% (95% CI 4.4-9.6%; I 2 = 77%; p < 0.001, Figure 3) for those with a low-risk Ottawa score.…”

Recurrence of Cancer-associated Venous Thromboembolism between 2009 and 2013: A Nationwide Korean Study

“…Consistently, our study found that being female was a risk factor for recurrence in patents with CAT. However, Girad et al 22 reported in their prospective cohort study that the Ottawa score failed to accurately predict recurrent VTE. Ahn et al 23 also failed to validate the Ottawa score in single-center, retrospective study.…”

Management of Cancer-Associated Thrombosis: Unmet Needs and Future Perspectives

“…56 When the risk score was applied and validated with the clinical trial data from the CLOT and CANTHANOX trials, it showed that a patient with a score of <0 had a low risk (5.1%), patients with a score of "0" had an intermediate risk (9.8%), and those with a score of !1 had a high risk (15.8%) of recurrent VTE. 56 However, in another prospective cohort study, the Ottawa score failed to predict the risk of VTE recurrence despite curative anticoagulation with LMWH in patients with CT. 57 More studies are required to validate the Ottawa score and to determine the best treatment option for cancer patients at risk of recurrent VTE.…”