A genotype-guided dosing algorithm was compared with a clinical dosing algorithm in patients starting anticoagulation with acenocoumarol or phenprocoumon. There was no difference between the two ...groups in the percentage of time in the therapeutic INR range of 2.0 to 3.0.
Coumarin anticoagulant agents such as acenocoumarol, phenprocoumon, and warfarin are frequently used for the prevention of stroke in patients with atrial fibrillation or for the treatment and prevention of venous thromboembolism.
1
In many countries, warfarin is used most frequently, but in some countries, acenocoumarol or phenprocoumon is prescribed.
2
Coumarin anticoagulant drugs have a narrow therapeutic window, and there are large interpatient and intrapatient variations in the dose requirement. The anticoagulant effect of these drugs is monitored by means of regular measurement of the international normalized ratio (INR).
3
A subtherapeutic INR is associated with an increased risk of stroke or thromboembolism, . . .
Aims
Polymorphisms in CYP2C9 and VKORC1 influence patients' phenprocoumon (PHE) and acenocoumarol (ACE) dose requirements. To provide physicians with tools to estimate the patient's individual dose, ...we aimed to develop algorithms for PHE and ACE.
Methods and results
In two Dutch anticoagulation clinics, data on age, sex, height, weight, co-medication, coumarin derivative doses, and international normalized ratio values were obtained from 624 patients taking PHE and 471 taking ACE. Single nucleotide polymorphisms relevant to coumarin derivative dosing on the CYP2C9 and VKORC1 genes were determined. Using multiple linear regression, we developed genotype-guided and non-genotype-guided algorithms to predict the maintenance dose with patient characteristics and genetic information. In addition, loading doses were derived from the calculated maintenance doses. We performed external validation in an independent data set with 229 PHE and 168 ACE users. CYP2C9 and VKORC1 genotype, weight, height, sex, age, and amiodarone use contributed to the maintenance dose of PHE and ACE. The genotype-guided algorithms explained 55.9% (PHE) and 52.6% (ACE) of the variance of the maintenance dose, the non-genetic algorithms 17.3% (PHE) and 23.7% (ACE). Validation in an independent data set resulted in an explained variation of 59.4% (PHE) and 49.0% (ACE) for the genotype-guided algorithms and for 23.5% (PHE) and 17.8% (ACE) for the non-genotype-guided algorithms, without height and weight as parameters.
Conclusion
To our knowledge, these are the first genotype-guided loading and maintenance dose algorithms for PHE and ACE using large cohorts. The utility of these algorithms will be tested in randomized controlled trials.
The pathophysiology of chronic thromboembolic pulmonary hypertension (CTEPH) is not fully understood. Poor-quality anticoagulation may contribute to a higher risk of CTEPH after acute pulmonary ...embolism (PE), partly explaining the transition from acute PE to CTEPH. We assessed the association between the time in therapeutic range (TTR) of vitamin-K antagonist (VKA) treatment and incidence of CTEPH after a PE diagnosis.
Case-control study in which the time spent in, under and above therapeutic range was calculated in 44 PE patients who were subsequently diagnosed with CTEPH (cases). Controls comprised 150 consecutive PE patients in whom echocardiograms two years later did not show pulmonary hypertension. All patients were treated with VKA for at least 6 months after the PE diagnosis. Time in (TTR), under and above range were calculated. Mean differences between cases and controls were estimated by linear regression.
Mean TTR during the initial 6-month treatment period was 72% in cases versus 78% in controls (mean difference -6%, 95%CI -12 to -0.1), mainly explained by more time above the therapeutic range in the cases. Mean difference of time under range was 0% (95%CI -6 to 7) and 2% (95CI% -3 to 7) during the first 3 and 6 months, respectively. In a multivariable model, adjusted odds ratios (ORs) for CTEPH were around unity considering different thresholds for 'poor anticoagulation', i.e. TTR <50%, <60% and <70%.
Subtherapeutic initial anticoagulation was not more prevalent among PE patients diagnosed with CTEPH than in those who did not develop CTEPH.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background After diagnosis of cancer-associated VTE, guidelines recommend considering the continuation of anticoagulant treatment until the patient is cured of cancer, although the safety of stopping ...anticoagulant treatment after the patient is cured has never been evaluated. Methods We conducted a cohort study in consecutive patients in whom cancer-associated VTE was diagnosed at the Leiden University Medical Center between January 2001 and January 2010 and monitored for the effect of cancer treatment, occurrence of recurrent VTE, major hemorrhage, and death. Results Of the 358 patients with cancer-associated VTE, anticoagulant treatment was continued until the death of 207 patients. In another 12 patients anticoagulant treatment was continued because of an alternative indication despite their being cured of cancer. Anticoagulant treatment was stopped in 50 patients for reasons other than major hemorrhage despite active cancer, in 21 patients after major hemorrhage, and in 68 patients after they had been cured of cancer. Among these 68 patients, 10 patients received a diagnosis of symptomatic recurrent VTE during a cumulative follow-up of 311 years, resulting in an incidence rate of 3.2 per 100 patient-years (95% CI, 1.5-5.9). Seven of these 10 patients with recurrent VTE experienced a cancer relapse during follow-up. For the 50 patients who stopped anticoagulant treatment despite active cancer the recurrent VTE incidence rate was 19 per 100 patient-years (11 events during 59 years of follow-up; 95% CI, 9.3-33). Conclusions Our data support the recommendation to stop anticoagulant treatment of cancer-associated VTE in patients cured of cancer. A cancer relapse seems to be a strong risk factor for recurrent symptomatic VTE.
Patients with a second venous thromboembolism generally receive anticoagulant treatment indefinitely, although it is known that the recurrence risk diminishes over time while the risk of hemorrhage ...persists with continued anticoagulation and increases with age. Based on these arguments and limited evidence for indefinitely prolonged treatment, the Dutch guidelines recommend considering treatment of a limited duration (i.e. 12 months) for a 'late' second venous thromboembolism, defined by a second venous thromboembolism diagnosed more than 1 year after discontinuing treatment for a first event. It is hypothesized that the risk of continued anticoagulation might outweigh the benefits in such circumstances. We evaluated this management in daily practice. Since 2003, limited duration of treatment was systematically considered at our hospital in consecutive patients, in whom we determined the recurrence risk. Of 131 patients with late second venous thromboembolism, 77 were treated for a limited duration, of whom 26 developed a symptomatic third venous thromboembolism thereafter during a cumulative follow-up of 277 years, resulting in an incidence rate of 9.4/100 patient-years (95% confidence interval: 6.1-14). The incidence rates in patients with unprovoked and provoked venous thromboembolism were 12/100 patient-years (95% confidence interval: 7.4-19) and 5.6/100 patient-years (95% confidence interval: 2.2-12), respectively adjusted hazard ratio 2.8 (95% confidence interval: 1.1-7.2). The recurrence risk after treatment of limited duration for 'late' second venous thromboembolism exceeded the risk of hemorrhage associated with extended anticoagulation. Most patients may, therefore, be better served by treatment of indefinite duration, although the risk-benefit ratio of extended anticoagulation should be weighed for every patient.
Background
Direct oral anticoagulants (DOACs) do not require concentration monitoring. However, whether DOAC concentrations are stable and their variation between and within patients is not well ...studied.
Methods
Patients on vitamin K antagonists (VKA) who switched to rivaroxaban, apixaban, or dabigatran were included between 2018 and 2020. Blood was drawn at DOAC trough and peak concentrations at week 0, 2, and 8. Plasma drug concentrations were determined by anti‐factor Xa concentrations (rivaroxaban, apixaban) or diluted thrombin time (dabigatran). Inter‐ and intra‐individual variability was assessed by calculating the coefficient of variation (CV). Linear regression models were employed to evaluate associations between DOAC trough concentrations and previous VKA dosage, creatinine clearance, and body mass index (BMI).
Results
One hundred fifty‐two patients were included, of whom 96 (63%) were male and with a mean age of 73.9 ± 8.4 years. For the inter‐individual variability, the CV ranged between 48% and 81% for trough values and between 25% and 69% for peak values among patients using the recommended DOAC dose. Intra‐individual variability was substantially lower, as here the CV ranged between 18% and 33% for trough values and between 15% and 29% for peak values among patients using the recommended DOAC dose. Previous VKA dosage and creatinine clearance were inversely associated with DOAC trough concentrations. No association was found between BMI and DOAC trough concentrations.
Conclusion
Inter‐individual variability of DOAC concentrations was higher than intra‐individual variability. Lower previous VKA dosage and creatinine clearance were associated with higher DOAC trough concentrations. These findings support further study into an optimal target range, in which the risks of both bleeding and thrombosis are minimal.
Background
Major bleeding occurs annually in 1%–3% of patients on vitamin K antagonists (VKAs), despite close monitoring. Genetic variants in proteins involved in VKA response may affect this risk.
...Aim
To determine the association of genetic variants (cytochrome P450 enzymes 2C9 CYP2C9 and 4F2 CYP4F2, gamma‐glutamyl carboxylase GGCX) with major bleeding in VKA users, separately and combined, including vitamin K epoxide reductase complex subunit‐1 (VKORC1).
Methods
A case‐cohort study was established within the BLEEDS cohort, which includes 16,570 patients who initiated VKAs between 2012 and 2014. We selected all 326 major bleeding cases that occurred during 17,613 years of follow‐up and a random subcohort of 978 patients. We determined variants in CYP2C9, CYP4F2, GGCX, VKORC1 and evaluated the interaction between variant genotypes. Hazard ratios for major bleeding with 95% confidence intervals (95% CI) were estimated by weighted Cox regression.
Results
Genotype was determined in 256 cases and 783 subcohort members. Phenprocoumon was the most prescribed VKA for both cases and the subcohort (78% and 75%, respectively). Patients with major bleeding were slightly older than subcohort patients. CYP4F2‐TT carriership was associated with a 1.6‐fold (95% CI 0.9–2.8) increased risk of major bleeding compared with CC‐alleles, albeit not statistically significant. For the CYP2C9 and GGCX variants instead, the major bleeding risk was around unity. Carrying at least two variant genotypes in CYP2C9 (poor metabolizer), CYP4F2‐TT, and VKORC1‐AA was associated with a 4.0‐fold (95%CI 1.4–11.4) increased risk, while carriers of both CYP4F2‐TT and VKORC1‐AA had a particularly increased major bleeding risk (hazard ratio 6.7, 95% CI 1.5–29.8) compared with carriers of CC alleles in CYP4F2 and GG in VKORC1. However, the number of major bleeding cases in carriers of multiple variants was few (8 and 5 patients, respectively).
Conclusions
CYP4F2 polymorphism was associated with major bleeding, especially in combination with VKORC1 genetic variants. These variants could be considered to further personalize anticoagulant treatment.
The HAS-BLED score enables a risk estimate of major bleeds in patients with atrial fibrillation on vitamin K-antagonists (VKA) treatment, but has not been validated for patients with venous ...thromboembolism (VTE). We analyzed whether the HAS-BLED score accurately identifies patients at high risk of major bleeds during VKA treatment for acute VTE.
Medical records of 537 patients with acute VTE (primary diagnosis pulmonary embolism in 223, deep vein thrombosis in 314) starting VKA treatment between 2006-2007 were searched for items on the HAS-BLED score and the occurrence of major bleeds during the first 180 days of follow-up. The hazard ratio (HR) for the occurrence of major bleeds comparing non-high with high-risk patients as defined by a HAS-BLED score ≥ 3 points was calculated using Cox-regression analysis.
Major bleeds occurred in 11/537 patients (2.0%, 5.2/100 person years, 95% CI 2.8-9.2). Cumulative incidences of major bleeds were 1.3% (95% CI 0.1-2.5) in the non-high (HAS-BLED < 3) and 9.6% (95%CI 2.2-17.0) in the high-risk group (HAS-BLED ≥ 3), (p <0.0001 by Log-Rank test), with a HR of 8.7 (95% CI 2.7-28.4). Of the items in the HAS-BLED score, abnormal renal function (HR 10.8, 95% CI 1.9-61.7) and a history of bleeding events (HR 10.4, 95% CI 2.5-42.5) were independent predictors of major bleeds during follow-up.
Acute VTE patients with a HAS-BLED score ≥ 3 points are at increased risk of major bleeding. These results warrant for correction of the potentially reversible risk factors for major bleeding and careful International Normalized Ratio monitoring in acute VTE patients with a high HAS-BLED score.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Hybrid PET-MRI systems are being used more frequently. One of the drawbacks of PET-MRI imaging is its inferiority in detecting lung nodules, so it is often combined with a computed tomography (CT) of ...the chest. However, chest CT often detects additional, indeterminate lung nodules. The objective of this study was to assess the sensitivity of detecting metastatic versus indeterminate nodules with PET-MRI compared to chest CT. A total of 328 patients were included. All patients had a PET/MRI whole-body scan for (re)staging of cancer combined with an unenhanced chest CT performed at our center between 2014 and 2020. Patients had at least a two-year follow-up. Six percent of the patients had lung metastases at initial staging. The sensitivity and specificity of PET-MRI for detecting lung metastases were 85% and 100%, respectively. The incidence of indeterminate lung nodules on chest CT was 30%. The sensitivity of PET-MRI to detect indeterminate lung nodules was poor (23.0%). The average size of the indeterminate lung nodules detected on PET-MRI was 7 ± 4 mm, and the missed indeterminate nodules on PET-MRI were 4 ± 1 mm (p < 0.001). The detection of metastatic lung nodules is fairly good with PET-MRI, whereas the sensitivity of PET-MRI for detecting indeterminate lung nodules is size-dependent. This may be an advantage, limiting unnecessary follow-up of small, indeterminate lung nodules while adequately detecting metastases.
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