Patients with acute pulmonary embolism (PE) often have leg deep vein thrombosis (DVT); sometimes, however, a DVT is not detected (isolated PE, I-PE). We aimed at assessing the proportion of patients with I-PE, and their characteristics and clinical evolution compared to those with DVT with/without PE (DVT/PE). Among 3573 patients included in the START2-Register for a venous thromboembolic event, 2880 (80.6%) had DVT/PE, the remaining I-PE (19.4%). Patients with I-PE were older [(≥75 years, OR 1.4 (95%CI 1.13-1.69)], and more frequently females [OR 1.4 (1.19-1.67)]. Young females (aged ≤ 50 years) with an index event occurring during hormonal contraception (HC), were more prevalent in I-PE [OR 1.96 (1.26-3.03)]. At multivariate analysis, age > 75 years, female sex, heart failure, cancer and use of HC were risk factors significantly associated with I-PE, whereas thrombophilic alterations were associated with DVT/PE. During a follow-up of 4504 years (during anticoagulation), the rate of bleeding events was 1.1% patient/years and 1.0% patient/years in I-PE and DVT/PE, respectively. Venous thromboembolic events were equally prevalent in DVT/PE or I-PE (1.94% vs 0.86%, ns), whereas arterial complications were more prevalent in the latter group (1.01% vs 0.28%, p = 0.008). I-PE and DVT/PE have important differences. Older age, female sex, heart failure and cancer, were risk factors for I-PE; thrombophilic alterations were associated with DVT/PE. HC use was more frequent in the I-PE group. The prevalence of arterial complications was higher in patients with I-PE. Further studies, specifically designed on this issue, are warranted.

Although effective and safe, treatment with direct oral anticoagulants (DOAC) in atrial fibrillation (AF) is still associated with thrombotic complications. Whether the measurement of DOAC levels may improve treatment efficacy is an open issue. We carried out the observational, prospective, multicenter Measure and See (MAS) study. Blood was collected 15 to 30 days after starting DOAC treatment in patients with AF who were followed-up for 1 year. Plasma samples were centralized for DOAC level measurement. Patients’ DOAC levels were converted into drug/dosage standardized values to allow a pooled analysis in a time-dependent, competitive-risk model. The measured values were transformed into standardized values (representing the distance of each value from the overall mean) by subtracting the DOAC-specific mean value from the original values and dividing by the standard deviation. Trough and peak DOAC levels were assessed in 1657 and 1303 patients, respectively. In total, 21 thrombotic complications were recorded during 1606 years of follow-up (incidence of 1.31% of patients per year). Of 21 thrombotic events, 17 occurred in patients whose standardized activity levels were below the mean of each DOAC (0); the incidence was the highest (4.82% of patients per year) in patients whose standardized values were in the lowest class (−1.00 or less). Early measurement of DOAC levels in patients with AF allowed us to identify most of the patients who, having low baseline DOAC levels, subsequently developed thrombotic complications. Further studies are warranted to assess whether thrombotic complications may be reduced by measuring baseline DOAC levels and modifying treatment when indicated. This trial was registered at www.ClinicalTrials.gov as #NCT03803579.

Treatment with direct oral anticoagulants (DOACs) in patients with atrial fibrillation (AF) is effective and safe. However, bleeding complications still occur. Whether DOAC level measurement may further improve treatment efficacy and safety is still an open issue. In the "Measure and See" study, venous blood was collected 15-30 days after DOAC initiation in patients with AF who were then followed up for 1 year to record the occurrence of major and clinically relevant nonmajor bleeding. DOAC plasma levels were measured in 1 laboratory, and results were kept blind to patients and treating doctors. Trough DOAC levels were assessed in 1657 patients (957 [57.7%] and 700 patients treated with standard and low-dose, respectively). Fifty bleeding events were recorded during 1606 years of follow-up (3.11% pt/yrs). Fifteen bleeding events (4.97% pt/yrs) occurred in patients with C-trough standardized values in the highest activity class (>0.50), whereas 35 events (2.69% pt/yrs) occurred in those with values in the 2 lower classes (≤0.50, P = .0401). Increasing DOAC levels and low-dose DOAC use were associated with increased bleeding risk in the first 3 months of treatment. Overall, 19% of patients receiving low doses had standardized values in the highest class. More bleeding occurred in patients on low (4.3% pt/yrs) vs standard (2.2% pt/yrs; P = .0160) dose DOAC. Early measurement of DOAC levels in patients with AF identified many individuals with high levels despite the low doses use and had more bleeding risk during the first 3 months of treatment. This trial was registered at www.ClinicalTrials.gov as #NCT03803579.

Direct oral anticoagulants (DOACs) have shown similar efficacy and safety with respect to warfarin in patients with atrial fibrillation (AF). However, the proportion of patients aged ≥85 years enrolled in clinical trials was low and the applicability of their results to very elderly patients is still uncertain. We have carried out a prospective cohort study on AF patients aged ≥85 years enrolled in the Survey on anticoagulaTed pAtients RegisTer (START2-Register) and treated with either VKAs or DOACs, with the aim to evaluate mortality, bleeding and thrombotic rates during a long-term follow-up. We enrolled 1124 patients who started anticoagulation at ≥85 years with VKA (58.7%) or DOACs (41.3%), Clinical characteristics of patients were similar, except for a higher prevalence of coronary artery disease and renal failure in VKAs patients and of a history of previous bleeding and previous stroke/TIA in patients on DOACs. Median CHA₂DS₂VASc and HAS-BLED scores were similar between the two groups. During follow-up, 47 major bleedings (rate 2.3 x100 pt-yrs) and 19 stroke/TIA (0.9 x100 pt-yrs) were recorded. The incidence of bleeding was similar between patients on VKAs and DOACs. Patients on DOACs showed a higher rate of thrombotic events during treatment (rate 1.84 and 0.50,respectively). Mortality rate was higher in patients on VKAs than in patients on DOACs (HR 0.64 (95% CI 0.46–0.91). In conclusion, we confirm the overall safety and effectiveness of anticoagulant treatment in very elderly AF patients, with lower mortality rates in DOACs patients, similar bleeding risk, and a higher risk for cerebral thrombotic events in DOACs patients.

The SAMe-TT2R2 score has recently been proposed to predict the quality of vitamin K antagonist (VKA) anticoagulation control in patients with atrial fibrillation. We aimed at investigating whether the score is effective also in patients with venous thromboembolism (VTE). Patients included in the START-Register because started VKA therapy for a recent VTE episode and with > 3 months follow-up were analyzed. The score was calculated using the baseline patient’s characteristics present in the electronic database of the registry, where all INR results were also available and analysed to calculate the time in therapeutic range (TTR). A total of 1308 patients (53.4 % female, median age 68 years) were analysed. During 998 patient-years followup, the median TTR was 63 %. The maximum score in the patients was 4, with 70 % of them having 0–1. INR controls within range (2.0–3.0) were significantly less prevalent in patients with score ≥ 2 vs 0–1 score (58.5 ± 20 % vs 61.5 ± 19 %, respectively, p = 0.046). Patients with score ≥ 2 vs 0–1 had a highly significant lower TTR during the first 3 months of therapy (53 ± 26 % and 61 ± 26 %, respectively; p=0.0001), difference mainly due to more time spent below 2.0 INR (38 ± 28 % vs 31.3 ± 26.7 %, respectively; p=0.0001). In conclusion, the study proved, for the first time, that the SAMe-TT₂R₂ score is useful to predict among VTE patients those who will have good (score 0–1) or less good (score ≥ 2) VKA anticoagulation control. The score can help decision-making in everyday clinical practice, especially when choosing between VKA and non-vitamin K antagonists direct anticoagulants. Note: The review process for this paper was fully handled by Christian Weber, Editor in Chief.