An analysis of HeartMate II left ventricular assist devices (LVADs) published in the March 11 issue of the Journal of the American College of Cardiology found that preoperative risk factors for bleeding and thrombotic events vary depending on patient demographics, including age, sex, body mass index and the cause of heart failure.

Researchers led by Andrew J. Boyle, MD, of the Cleveland Clinic Florida in Weston, Fla., evaluated data from patients with advanced heart failure discharged after HeartMate II LVAD (Thoratec) implantation performed during the bridge to transplantation and destination therapy clinical trials. The outcomes were bleeding requiring surgery or transfusion of two units of packed red blood cells, stroke and pump thrombosis.

There were 956 LVAD patients discharged, and there were 0.67 adverse event rates for post-discharge bleeding per year, higher than for hemorrhagic stroke, ischemic stroke and pump thrombosis. Bleeding most often occurred in the gastrointestinal tract (45 percent), from wounds (12 percent) and from the nose (4 percent).

Risk factors associated with bleeding were older age (older than 65, hazard ratio [HR] 1.31, hematocrit of 31 percent or lower (HR 1.31), ischemic etiology of heart failure (HR 1.35) and female sex (HR 1.45). Risk factors for hemorrhagic stroke were female sex (HR 1.92) and being 65 and younger (HR 1.94). For ischemic stroke, female sex (HR 1.94) and diabetes (HR 1.99) were risk factors. Female sex (HR 1.90) and higher body mass index (HR 1.71 for every 10 kg/m increase) were risk factors for pump thrombosis.

“The findings of this study may help to identify a unique patient profile for appropriately targeting an anticoagulation regimen to reduce the risk of bleeding,” the authors wrote, but they added that future research should evaluate the impact of tailored anticoagulation therapy in different patient subgroups.

In an accompanying editorial, Samer S. Najjar, MD, of MedStar Washington Hospital Center in Washington, explained that patient risk factors are not generally taken into account when considering an anticoagulation regimen. Clinicians rely on anticoagulation targets set by the manufacturer unless there are clinical events such as bleeding or comorbidities that require adjustment.

“Identifying the additional demographic and clinical factors that modulate the risks of bleeding and thrombosis will enhance our ability to risk-stratify patients with LVADs,” he wrote.