Influence of thrombocytopenia on bleeding and vascular events in atrial fibrillation

Patients with atrial fibrillation and common exclusion criteria from clinical trials are at high risk of clinical events: the Murcia AF Project II (MAFP-II) cohort study

BACKGROUND

Some clinical characteristics and comorbidities in atrial fibrillation (AF) patients are exclusion criteria in randomized clinical trials (RCTs) investigating oral anticoagulants (OAC). However, these conditions are present also in everyday clinical practice patients. We compared the risk of adverse clinical outcomes between patients with and without RCT exclusion criteria.

METHODS

The Murcia AF Project II was an observational cohort study including AF outpatients starting vitamin K antagonists (VKAs) from July 2016 to June 2018. For the selection of the exclusion criteria, the four pivotal RCTs of direct-acting OAC (DOACs) were used as reference. During 2 years, all ischemic strokes/transient ischemic attacks, major adverse cardiovascular events (MACEs), major bleeds, and all-cause deaths were recorded.

RESULTS

1050 patients (51.5% female, median age 77 years) were included, of whom 368 (35%) met at least one exclusion criterion for RCTs. During follow-up, the incidence rate ratios for major bleeding, MACE and all-cause mortality were higher among patients with exclusion criteria (all p < 0.001). Patients fulfilling at least one exclusion criterion had increased risks of major bleeding (aHR 1.48; 95% CI 1.22-1.81; p < 0.001), MACE (aHR 1.51, 95% CI 1.10-2.09, p = 0.012), and mortality (aHR 3.22, 95% CI 2.32-4.48, p < 0.001), as well as a lower event-free survival (all log-rank p < 0.001).

CONCLUSIONS

In this AF cohort taking VKAs, more than one-third had at least one RCT exclusion criteria, which translates into higher risk of major bleeding, MACE, and death. These observations should be considered when translating RCTs results to AF patients for a proper and a more patient-centered management.

Arterial Thrombosis in Patients with Cancer

Patients with cancer are at increased risk of arterial thromboembolic disease due to the presence of risk factors common to both the development of cancer and arterial thrombosis, the cancer itself, and the treatments provided to treat cancer. We review here the epidemiology and pathophysiology of arterial thromboembolic disease in cancer, along with its prevention and treatment strategies. We also propose a generalized approach for the management of arterial thromboembolic disease in this patient population.

Anticoagulation in cancer patients with atrial fibrillation and grade 3-4 thrombocytopenia

INTRODUCTION

Atrial fibrillation or flutter (AF) is prevalent in cancer patients. Many of these patients have an indication for anticoagulation (AC) but are also at risk for developing chemotherapy-induced thrombocytopenia. There are scarce data regarding management of AC and risk of bleeding and thrombosis in cancer patients with AF and thrombocytopenia.

AIM

To assess anticoagulation management and incidence of bleeding and arterial thromboembolism (ATE) in cancer patients with AF and grade 3-4 thrombocytopenia (platelets <50 × 109/L).

METHODS

A retrospective cohort study included adults with active cancer, grade 3-4 thrombocytopenia and AF with CHA2DS2-VASc score ≥ 1. Patients were stratified according to AC discontinuation (No-AC) or continuation (Continue-AC) when platelets dropped below 50 × 109/L and followed for 30 days. The study outcomes were ATE (ischemic stroke, transient ischemic attack or systemic emboli) and major bleeding. Cox proportional hazards model was used to calculate hazard ratios (HR) with death as a competing risk (Fine and Gray model).

RESULTS

The cohort included 131 patients; 90 in the No-AC group and 41 in the Continue-AC group. Patient characteristics were balanced between the groups. The 30-day cumulative incidence of ATE was 2 % [95 % CI 0.4 %-7 %] in the No-AC group and 2 % [0.2 %-11 %] in the Continue-AC group (HR 0.92 [95 % CI 0.09-9.88]). The 30-day cumulative incidence of major bleeding was 7.8 % [95 % CI 3.40 %-14.52 %] and 2.44 % [95 % CI 0.18 %-11.22 %] in the No-AC and Continue-AC groups, respectively (HR 3.29 [95 % CI 0.42-26.04]).

CONCLUSIONS

The high rate of bleeding and low rate of ATE in thrombocytopenic cancer patients with AF suggests that holding AC during time-limited periods may be a reasonable approach.