Ann Pekarek

Gender differences in the risk of stroke during support with continuous-flow left ventricular assist device

BACKGROUND There is increasing recognition that the risk of stroke after left ventricular assist device (LVAD) implantation varies based on gender, with a higher risk in female patients. We reviewed our own data to determine gender differences in the risk of stroke. METHODS Frequency of stroke, including intracranial hemorrhage and ischemic stroke, was retrospectively evaluated in 110 heart failure patients (mean age 49.6 ± 13.6 years, 32% women) discharged from the hospital after implantation of a HeartMate II (N = 74) or HeartWare (N = 36) LVAD. Competing outcomes analysis was used to determine which clinical risk factors were associated with the risk of stroke and death, with the primary end-point being time to first stroke event. RESULTS During a median follow-up of 1.3 years, 26 patients had a stroke (23.6%, 0.14 case per person-year). The median time to first stroke was 0.7 (interquartile range 0.3 to 1.4) years. After adjusting for covariates, risk of stroke was higher for women than for men (hazard ratio 3.1, 95% confidence interval 1.4 to 6.9; p = 0.007). There was no difference in overall survival between men and women. CONCLUSION The risk of stroke after LVAD varies based on gender, with a higher risk in female patients. More research is needed to fully understand these differences, and whether device management strategies should be tailored based on gender.

The Right Ventricular Function After Left Ventricular Assist Device (RVF-LVAD) study: rationale and preliminary results

AIMS Despite improved outcomes and lower right ventricular failure (RVF) rates with continuous-flow left ventricular assist devices (LVADs), RVF still occurs in 20-40% of LVAD recipients and leads to worse clinical and patient-centred outcomes and higher utilization of healthcare resources. Preoperative quantification of RV function with echocardiography has only recently been considered for RVF prediction, and RV mechanics have not been prospectively evaluated. METHODS AND RESULTS In this single-centre prospective cohort study, we plan to enroll a total of 120 LVAD candidates to evaluate standard and mechanics-based echocardiographic measures of RV function, obtained within 7 days of planned LVAD surgery, for prediction of (i) RVF within 90 days; (ii) quality of life (QoL) at 90 days; and (iii) RV function recovery at 90 days post-LVAD. Our primary hypothesis is that an RV echocardiographic score will predict RVF with clinically relevant discrimination (C >0.85) and positive and negative predictive values (>80%). Our secondary hypothesis is that the RV score will predict QoL and RV recovery by 90 days. We expect that RV mechanics will provide incremental prognostic information for these outcomes. The preliminary results of an interim analysis are encouraging. CONCLUSION The results of this study may help improve LVAD outcomes and reduce resource utilization by facilitating shared decision-making and selection for LVAD implantation, provide insights into RV function recovery, and potentially inform reassessment of LVAD timing in patients at high risk for RVF.

Multidrug-Resistant Organism Infections in Patients with Left Ventricular Assist Devices

Left ventricular assist devices improve survival prospects in patients with end-stage heart failure; however, infection complicates up to 59% of implantation cases. How many of these infections are caused by multidrug-resistant organisms is unknown. We sought to identify the incidence, risk factors, and outcomes of multidrug-resistant organism infection in patients who have left ventricular assist devices. We retrospectively evaluated the incidence of multidrug-resistant organisms and the independent risk factors associated with them in 57 patients who had permanent left ventricular assist devices implanted at our institution from May 2007 through October 2011. Outcomes included death, transplantation, device explantation, number of subsequent hospital admissions, and number of subsequent admissions related to infection. Infections were categorized in accordance with criteria from the Infectious Diseases Council of the International Society for Heart and Lung Transplantation. Multidrug-resistant organism infections developed in 18 of 57 patients (31.6%)-a high incidence. We found 3 independent risk factors: therapeutic goal (destination therapy vs bridging), P=0.01; body mass index, P=0.04; and exposed velour at driveline exit sites, P=0.004. We found no significant differences in mortality, transplantation, or device explantation rates; however, there was a statistically significant increase in postimplantation hospital admissions in patients with multidrug-resistant organism infection. To our knowledge, this is the first report in the medical literature concerning multidrug-resistant organism infection in patients who have permanent left ventricular assist devices.