Risk of recurrent venous thromboembolism after discontinuation of vitamin K antagonist treatment: a nested case-control study

Rosuvastatin treatment decreases plasma procoagulant phospholipid activity after a VTE: A randomized controlled trial

BACKGROUND

Venous thromboembolism (VTE) is a frequent cardiovascular disease with severe complications, including recurrence and death. There is a great need for alternative prophylactic treatment options as anticoagulation is accompanied by increased bleeding risk. Statins are reported to reduce the risk of incident and recurrent VTE, but the mechanisms are elusive. Procoagulant phospholipids (PPL), and phosphatidylserine in particular, are crucial for efficient coagulation activation, but no studies have investigated the effect of statin treatment on plasma PPL activity.

OBJECTIVES

To investigate the impact of rosuvastatin treatment on plasma PPL activity and levels of extracellular vesicles (EVs).

PATIENTS/METHODS

Patients with a history of VTE (≥18 years) allowed to stop anticoagulant treatment were randomized to either 20 mg/day of rosuvastatin treatment or no treatment for 28 days in the Statins Reduce Thrombophilia (NCT01613794) trial. Plasma samples were collected at baseline and study end. PPL activity was measured in samples from 245 participants using a factor Xa-dependent clotting assay and EV levels by flow cytometry.

RESULTS

Rosuvastatin treatment yielded an overall 22% (95% confidence interval [CI] -38.2 to -5.8) reduction in PPL activity, and 37% (95% CI -62.9 to -11.2) reduction in PPL activity in participants with a history of pulmonary embolism. The effect of rosuvastatin on plasma PPL activity was not explained by changes in total cholesterol nor change in levels of total- or platelet-derived EVs.

CONCLUSIONS

Rosuvastatin treatment caused a substantial decrease in plasma PPL activity, suggesting that a PPL-dependent attenuation of coagulation activation may contribute to a reduced VTE risk following statin treatment.

Association between adherence to warfarin and thrombotic events in patients with antiphospholipid syndrome in Japan: A claims-based retrospective cohort study

PURPOSE

We aimed to evaluate adherence and persistence to warfarin therapy among patients with antiphospholipid syndrome (APS) and investigate the association between adherence and thrombotic events in those patients.

METHODS

We conducted a retrospective cohort study using the Japan Medical Data Center claims database from 2005 to 2018. Patients with APS receiving warfarin treatment were included in this study. Adherence and persistence were evaluated using the proportion of days covered (PDS) and refill gap methods, respectively. Demographic characteristics of patients were obtained. Kaplan-Meier curves with log-rank tests and Cox regression models were used to examine the association between adherence or persistence and time to thrombotic events.

RESULTS

A total of 186 patients (mean age: 46.5 ± 12.4 years, females 68.8%) were included in this study. No significant differences were observed in risk factors for thrombosis and cardiovascular diseases among groups. Most patients were adherent (91.4%) and persistent (88.2%) to warfarin treatment. Adherent and persistent patients had a significantly higher rate of thrombotic event-free survival than nonadherent and nonpersistent patients (p < 0.05). Multivariable Cox regression showed that the risk of thrombotic events was higher in nonadherent patients (with a hazard ratio of 3.23 [95% confidence interval CI: 1.15-9.11]) and in nonpersistent patients (with a hazard ratio of 3.45 [95% CI: 1.35-8.82]).

CONCLUSIONS

In patients with APS, nonadherence and nonpersistence to warfarin treatment was associated with a higher risk of thrombotic events, suggesting the careful monitoring of those patients.

Thrombolysis of Postoperative Acute Pulmonary Embolism with a Thrombus in Transit

Right heart thrombus in transit clot (RHTT) associated with a pulmonary thromboembolism (PTE) is a rare but potentially fatal diagnosis. Early diagnosis and immediate intervention are crucial. This report describes the case of a healthy, physically active 32-year-old female who presented 19 days postoperatively, following an anterior cruciate ligament reconstruction and partial lateral meniscectomy with a saddle PE, RHTT, and right ventricular (RV) strain. The patient received half of the standard dose of intravenous tissue plasminogen activator (TPA) in combination with anticoagulation and survived. Case reports of RHTT will inform future studies designed to evaluate whether and when thrombolysis should be administered.

Rosuvastatin use increases plasma fibrinolytic potential: a randomised clinical trial

We conducted a study to assess the effect of rosuvastatin use on fibrinolysis in patients with previous venous thromboembolism (VTE). This was a post hoc analysis within the STAtins Reduce Thrombophilia (START) study (NCT01613794). Plasma fibrinolytic potential, fibrinogen, plasmin inhibitor, plasminogen activator inhibitor‐1 (PAI‐1) and thrombin‐activatable fibrinolysis inhibitor (TAFI) were measured before and after four weeks of rosuvastatin or no treatment in participants with prior confirmed VTE, after ending anticoagulant therapy. In the non‐rosuvastatin group (n = 121), plasma fibrinolytic potential and individual fibrinolysis parameters did not change at the end of the study versus the baseline, whereas in the rosuvastatin group (n = 126), plasma fibrinolytic potential increased: the mean clot lysis time decreased by 8·75 min (95% CI −13·8 to −3·72), and plasmin inhibitor levels and TAFI activity were lower at the end of the study (−0·05 U/ml; 95% CI −0·07 to −0·02 and −4·77%; 95% CI −6·81 to −2·73, respectively). PAI‐1 levels did not change and fibrinogen levels were 0·17 g/l (95% CI 0·04–0·29) higher. In participants with prior VTE, rosuvastatin use led to an increased fibrinolytic potential compared with non‐statin use. Our findings support the need for further studies on the possible role for statins in the secondary prevention of VTE.

Ischemic Stroke and Transient Ischemic Attack Risk Following Vitamin K Antagonist Cessation in Newly Diagnosed Atrial Fibrillation: A Cohort Study

Background In nonvalvular atrial fibrillation (AF), oral anticoagulants prevent ischemic strokes and transient ischemic attacks (TIAs), but nonpersistence with vitamin K antagonist (VKA) oral anticoagulant therapy (20-50% at 1 year) is problematic. The precise risk of stroke/TIA after VKA cessation and its time course during extended follow-up is unknown. Methods and Results The study cohort of incident AF in patients receiving initial VKA between 2001 and 2013 was identified from the UK Clinical Practice Research Datalink (linked hospitalizations and causes of death). Using a nested case-control analysis, patients with incident stroke/TIA were matched to patients without stroke/TIA (controls). Relative risk with time since VKA cessation compared with current VKA use was approximated from conditional logistic regression. We studied 16 696 patients with incident AF and initial VKA treatment. There were 489 stroke/TIA cases matched to 2137 controls (mean CHA₂DS₂-VASc score 4.3). Compared with current VKA use, the excess incidence rate of stroke/TIA following VKA cessation in the first year after AF diagnosis was 2.29 (95% CI, 0.98-3.90) per 100 person-years of VKA cessation or 1 additional stroke/TIA per 43 patients per year discontinuing VKA, compared with 1.43 (95% CI, 0.97-1.88) per 100 person-years corresponding to 1 additional stroke/TIA per 70 patients per year, when VKA was discontinued more than 1 year after AF diagnosis. Conclusions VKA cessation is associated with a continuous excess thromboembolic stroke/TIA risk. Increasing oral anticoagulant persistence, especially in the year after AF diagnosis, should be a therapeutic target to reduce stroke/TIA in AF.

Rosuvastatin use improves measures of coagulation in patients with venous thrombosis

Aims

Observational studies indicate that statins reduce the risk of recurrent venous thrombosis (VT). However, trials have not been performed and the mechanism is unknown. We aimed to determine whether statin therapy improves the coagulation profile in patients with prior VT.

Methods and results

Randomized clinical trial (NCT01613794). Patients were randomized to rosuvastatin 20 mg/day for 4 weeks or no intervention. Blood was drawn at baseline and at end of study. The primary outcome was factor (F) VIII:C. In total, five coagulation factors were measured: FVIII:C, von Willebrand factor:Ag, FVII:C, FXI:C, and D-dimer. Among 247 randomized participants, mean age was 58 years, 62% were women and 49% had unprovoked VT. For all tested coagulation factors, mean levels were clearly decreased at end of study in rosuvastatin users, whereas they hardly differed in non-statin users. Results were most consistent for FVIII:C where mean FVIII:C levels were 7.2 IU/dL [95% CI (confidence interval) 2.9-11.5] lower in rosuvastatin users, while among non-users, no change in FVIII:C was observed (mean difference -0.1; 95% CI -3.0 to 2.9). The mean age and sex adjusted difference in FVIII:C change was -6.7 IU/dL (95% CI -12.0 to -1.4) in rosuvastatin users vs. non-users. Subgroup analyses revealed that the decrease in coagulation factors by rosuvastatin was more pronounced in participants with unprovoked VT and in those with cardiovascular risk factors.

Conclusion

Rosuvastatin 20 mg/day substantially improved the coagulation profile among patients with prior VT. These results suggest that statin therapy might be beneficial in patients at risk of recurrent VT.

Risk prediction of recurrent venous thrombosis; where are we now and what can we add?

BACKGROUND

Several models are available to predict recurrent venous thrombosis (VT) in patients with unprovoked first events.

OBJECTIVES

To validate these prediction models externally.

METHODS

Within the MEGA follow-up study (n = 3750), we externally validated the Vienna and DASH score. These models were validated (a) by using the original study's criteria for patients with unprovoked VT and (b) by using our own criteria for unprovoked VT. In addition, absolute recurrence risks based on individual VT risk factors were calculated.

RESULTS

The recurrence rate was 5.2 (95% CI, 4.6-5.9) per 100 patient-years in those who had a first unprovoked VT according to our definition. For the Vienna model it was 3.4 per 100 patient-years and for DASH 3.8 per 100 patient-years. The C-statistic was 0.62 for Vienna and 0.65 for DASH. The C-statistic declined to 0.58 for both Vienna and DASH when we used our own definition of "unprovoked VT." Within the provoked group a strong gradient in risk was found dependent on the presence of traditional risk factors or biomarkers in a patient.

CONCLUSIONS

The ability to distinguish patients' recurrence risks is lower than proposed in the original prediction model studies and dependent on the definition that is used for an unprovoked first event. Furthermore, our results suggest that a more-refined risk estimation is possible, also in patients with a provoked first event, who are currently all classified as low risk.

Rosuvastatin use reduces thrombin generation potential in patients with venous thromboembolism: a randomized controlled trial

Essentials The role of statins in hemostasis and venous thromboembolism (VTE) prophylaxis is not clear. This trial assessed whether rosuvastatin use affects thrombin generation in patients with VTE. Endogenous thrombin potential and peak were decreased by 10% and 5% with rosuvastatin therapy. These results provide basis for trials on the efficacy of statins in reducing recurrent VTE risk. SUMMARY: Background Statin therapy could form an alternative prophylactic treatment for venous thromboembolism (VTE) if statins are proven to downregulate hemostasis and prevent recurrent VTE, without increasing bleeding risk. Objectives The STAtins Reduce Thrombophilia (START) trial investigated whether statin affects coagulation in patients with prior VTE. Patients/methods After anticoagulation withdrawal, patients were randomized to rosuvastatin 20 mg day-1 for 4 weeks or no intervention. Plasma samples taken at baseline and at the end of the study were analyzed employing thrombin generation assay. Results and conclusions The study comprised 126 rosuvastatin users and 119 non-users. Mean age was 58 years, 61% were men, 49% had unprovoked VTE and 75% had cardiovascular (CV) risk factors. Endogenous thrombin potential (ETP) increased from baseline to end of study in non-statin users (mean 97.22 nm*min; 95% CI, 40.92-153.53) and decreased in rosuvastatin users (mean -24.94 nm*min; 95% CI, -71.81 to 21.93). The mean difference in ETP change between treatments was -120.24 nm*min (95% CI, -192.97 to -47.51), yielding a 10.4% ETP reduction by rosuvastatin. The thrombin peak increased in both non-statin (mean 20.69 nm; 95% CI, 9.80-31.58) and rosuvastatin users (mean 8.41 nm; 95% CI -0.86 to 17.69). The mean difference in peak change between treatments was -11.88 nm (95% CI, -26.11 to 2.35), yielding a 5% peak reduction by rosuvastatin. Other thrombin generation parameters did not change substantially. The reduction in ETP and peak by rosuvastatin was more pronounced in the subgroups of participants with CV risk factors and with unprovoked VTE. We conclude that rosuvastatin reduces thrombin generation potential in patients who had VTE.

Thirty-day outcomes in patients with acute pulmonary embolism who discontinued anticoagulant therapy before 90 days

BACKGROUND

The contemporary natural history of patients with acute pulmonary embolism (PE) not receiving (or early discontinuing) anticoagulant therapy has not been consistently evaluated.

OBJECTIVE

To assess the rate of the composite outcome of PE-related death, sudden death, or recurrent thromboembolism (VTE) within 30 days in all PE patients in whom anticoagulation was not administered or discontinued prematurely (<90 days of anticoagulation).

METHODS

We used the RIETE database to assess the incidence rates (per 100 person-days) of the composite outcome within the subsequent 30 days. The risk of these events was compared to PE patients who were anticoagulated for ≥90 days.

RESULTS

Of 34,447 PE recruited from 2001 to 2017, 47 (0.14%) did not receive anticoagulants and 1348 (3.91%) discontinued it before 90 days. Fatal PE developed in 25 (53%) of those without any anticoagulation and in 45 (3.33%) with premature discontinuations. Sudden death or non-fatal recurrent VTE occurred in 6 (0.45%) and 24 (1.48%) patients, respectively. The incidence of the primary outcome declined logarithmically from 6.36 per 100 patient-days in untreated patients to 0.32-0.13 in those treated for 8-90 days. During the first week of follow-up, the incidence rate was 13.9 and 0.60-0.31 per 100 patient-days, respectively. The adjusted odds of the primary outcome was 27 fold higher in untreated than in treated patients, and progressively decreased to 2.5-7 fold higher in patients treated for at least 7 days.

CONCLUSION

The incidence of the composite outcome was highest during the first week, and inversely and logarithmically correlated with the duration of anticoagulant therapy.

Thromboembolic and neurologic sequelae of discontinuation of an antihyperlipidemic drug during ongoing warfarin therapy

Warfarin and antihyperlipidemics are commonly co-prescribed. Some antihyperlipidemics may inhibit warfarin deactivation via the hepatic cytochrome P450 system. Therefore, antihyperlipidemic discontinuation has been hypothesized to result in underanticoagulation, as warfarin metabolism is no longer inhibited. We quantified the risk of venous thromboembolism (VTE) and ischemic stroke (IS) due to statin and fibrate discontinuation in warfarin users, in which warfarin was initially dose-titrated during ongoing antihyperlipidemic therapy. Using 1999-2011 United States Medicaid claims among 69 million beneficiaries, we conducted a set of bidirectional self-controlled case series studies-one for each antihyperlipidemic. Outcomes were hospital admissions for VTE/IS. The risk segment was a maximum of 90 days immediately following antihyperlipidemic discontinuation, the exposure of interest. Time-varying confounders were included in conditional Poisson models. We identified 629 study eligible-persons with at least one outcome. Adjusted incidence rate ratios (IRRs) for all antihyperlipidemics studied were consistent with the null, and ranged from 0.21 (0.02, 2.82) for rosuvastatin to 2.16 (0.06, 75.0) for gemfibrozil. Despite using an underlying dataset of millions of persons, we had little precision in estimating IRRs for VTE/IS among warfarin-treated persons discontinuing individual antihyperlipidemics. Further research should investigate whether discontinuation of gemfibrozil in warfarin users results in serious underanticoagulation.

Acquired Vitamin K Deficiency as Unusual Cause of Bleeding Tendency in Adults: A Case Report of a Nonhospitalized Student Presenting with Severe Menorrhagia

We report a rare case of acquired vitamin K deficiency presenting with severe menorrhagia and without any gynecological problem. Partial thromboplastin time (59.2 seconds) and prothrombin time (33.1 seconds, INR: 5.97) were considerably prolonged in laboratory evaluations. A complete coagulation factor assay test was performed for the patient: factor IX, 24%; factor II, 41%; factor VII, 3%; and factor X, 52%. She had been taking many high-energy drinks and she had inadequate dietary intake for the past 6 months. Given that she had vitamin K deficiency (VKD), a course of vitamin K therapy was started for her in the hospital. This case showed the potential for menorrhagia due to VKD with use of high-energy drinks and the value of a complete and detailed history in early diagnosis.