Adamson, Robert

The PREVENtion of HeartMate II pump Thrombosis through clinical management (PREVENT) study was a multicenter, prospective investigation to evaluate the rate of pump thrombosis (PT) with adoption of a uniform set of surgical and medical practices for left ventricular assist device implantation. We sought to quantify pump position at baseline and retrospectively define a pump position associated with poor clinical outcomes. Chest x-rays at baseline were prospectively obtained per protocol. Pump pocket depth, inflow cannula (IC) angle relative to the pump, and IC angle relative to the vertical were measured. Pumps falling in the tail-ends of the IC angle and pump pocket depth distributions were categorized as having an extreme pump position within the PREVENT study. Patients with extreme pump position had a significantly higher risk of confirmed and suspected PT, hemolysis, and elevated lactate dehydrogenase. In a multivariable analysis of survival free of confirmed PT, extreme pump position was an independent risk factor (hazard ratio = 3.6; 95% confidence interval = 1.5–8.9; p = 0.006) when adjusting for differences in pump speed and anticoagulation level. Our analysis shows that HeartMate II pump position at implant can significantly impact event-free survival and the incidence of adverse events at 6 months.

Background— The HeartMate II (HMII) destination therapy (DT) trial demonstrated significant improvements in outcomes in continuous-flow left ventricular assist devices compared with patients implanted with the pulsatile-flow HeartMate XVE. The primary hypothesis of the current study is that trial patients enrolled after the initial data cohort would have better clinical outcomes. Methods and Results— Two hundred eighty-one patients who underwent HMII for DT from May 2007 to March 2009 (Mid Trial [MT] group) were compared with the initial 133 HMII patients from March 2005 to May 2007 (Early Trial [ET] group). Patient entry criteria were the same during the 2 time periods. Survival, adverse events, and quality of life were compared between the 2 groups. Baseline characteristics were similar between the groups. Compared with the ET group, patients in the MT group had reduced adverse event rates for bleeding requiring transfusions (1.66 versus 1.13 events per patient-year, P <0.001), sepsis (0.38 versus 0.27, P =0.025), device-related infections (0.47 versus 0.27, P <0.001), and hemorrhagic stroke (0.07 versus 0.03, P =0.01). Other event rates were similar between groups including ischemic stroke (0.06 versus 0.05 events per patient-year, P =0.57). Survival at 1 year in the MT group was 73% versus 68% in the ET group ( P =0.21). Additionally, there was a significant reduction in deaths caused by hemorrhagic stroke ( P =0.01). Quality of life improvements were significant in both the groups ( P <0.001). Conclusions— The benefit of DT therapy with the HMII is confirmed in subsequent trial patients, with improved adverse event rates and a strong trend for improvements in survival. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00121485.