VTE mortality risk persists long term
MedWire News: An increased risk for death may persist for up to 8 years among patients with a first venous thromboembolism (VTE), even when no comorbidities are present at the time of thrombosis, Dutch researchers report.
"VTE is a common disease with a high mortality rate shortly after the event. However, details on long-term mortality in these patients are lacking," say Frits Rosendaal and colleagues from Leiden University Medical Center.
To address this, the researchers compared mortality rates among 4947 patients, aged 18 to 70 years, with a first nonfatal deep vein thrombosis (DVT) or pulmonary embolism (PE) with those among 6154 control individuals without DVT or PE. All of the study participants were followed-up for a maximum of 8 years (median of 5.5 years for patients and 4.0 years for controls).
During the follow-up period, 601 patients and 135 controls died, giving overall mortality rates of 22.7 per 1000 person-years for the patients and 4.7 per 1000 person-years for the controls.
The standardized mortality ratio (SMR) for patients versus controls was 4.0, indicating that the patients were four times more likely to die during follow-up than controls.
The increased mortality risk persisted throughout the follow-up period, with patients having a 3.8-fold increased risk for death at 8 years, compared with controls, even after controlling for age, gender, and number of comorbidities.
As expected, patients with VTE and cancer had the highest risk for death; they were 17.2 times more likely to die during follow-up than controls overall, and 5.5 times more likely to die compared with only the controls that had cancer.
However, the increased mortality was not confined to patients with cancer. Indeed, patients with VTE but no cancer were more than twice as likely (SMR=2.2) to die than controls, and the increased risk was similar for patients with DVT and PE and for patients with a provoked or an idiopathic thrombosis.
The relative risk for death was highest during the first 3 years in all VTE subgroups, and it remained elevated by around twofold for up to 8 years in all but those with a transient provoking risk factor underlying the initial event.
The researchers note that when they stratified the cohort into those with and without comorbidities, they found that patients with comorbidities were no more likely to die than controls with comorbidities. By contrast, patients without comorbidities had a 2.5-fold increased risk for death compared with controls without comorbidities.
"The increased risk of death among patients with venous thrombosis can therefore not be fully explained by the presence of these concurrent disorders," Rosendaal et al remark.
They conclude that long-term clinical follow-up "could be beneficial" in patients who have experienced a first VTE.
By Laura Cowen