N. Kunz

Blood Pressure Control in Continuous Flow Left Ventricular Assist Devices: Efficacy and Impact on Adverse Events

BACKGROUND Continuous flow (CF) left ventricular assist devices (LVAD) are afterload sensitive and therefore pump performance is affected by hypertension. In addition, poorly controlled hypertension may increase the risk of aortic insufficiency (AI) and stroke. Blood pressure regimens after CF LVAD have not been studied and their impact on rates of AI and stroke are unknown. METHODS Patients who had CF LVAD at a single center and were supported greater than 30 days were included. Blood pressure was monitored at home by Doppler. Outpatient management of blood pressure was conducted according to a predefined institutional protocol (target mean arterial pressure ≤ 80 mm Hg). RESULTS A total of 96 patients were included. At the end of follow-up, 25 patients were not on an antihypertensive drug, of these 9 died. Of the 74% receiving antihypertensives, 54% required 1 medication, 34% were on 2, 10% were on 3, and 3% were on 4 or more. Angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers (85% of patients on an antihypertensive) and beta blockers (30%) were the most commonly prescribed medications. There was a significantly higher neurologic event rate in those on no antihypertensives compared with those on antihypertensives (p = 0.009). Only 3% of patients with no or mild AI at baseline progressed to develop moderate or greater AI after a mean of 201 days of follow-up. CONCLUSIONS Blood pressure control can be achieved in patients with CF LVADs, with the majority of patients requiring only 1 or 2 antihypertensives.

Preoperative liver dysfunction influences blood product administration and alterations in circulating haemostatic markers following ventricular assist device implantation

OBJECTIVES Preoperative liver dysfunction may influence haemostasis following ventricular assist device (VAD) implantation. The Model for End-stage Liver Disease (MELD) score was assessed as a predictor of bleeding and levels of haemostatic markers in patients with currently utilized VADs. METHODS Sixty-three patients (31 HeartMate II, 15 HeartWare, 17 Thoratec paracorporeal ventricular assist device) implanted 2001-11 were analysed for preoperative liver dysfunction (MELD) and blood product administration. Of these patients, 21 had additional blood drawn to measure haemostatic marker levels. Cohorts were defined based on high (≥18.0, n = 7) and low (<18.0, n = 14) preoperative MELD scores. RESULTS MELD score was positively correlated with postoperative administration of red blood cell (RBC), platelet, plasma and total blood product units (TBPU) , as well as chest tube drainage and cardiopulmonary bypass time. Age and MELD were preoperative predictors of TBPU by multivariate analysis. The high-MELD cohort had higher administration of TBPU, RBC and platelet units and chest tube drainage postimplant. Similarly, patients who experienced at least one bleeding adverse event were more likely to have had a high preoperative MELD. The high-MELD group exhibited different temporal trends in F1 + 2 levels and platelet counts to postoperative day (POD) 55. D-dimer levels in high-MELD patients became elevated versus those for low-MELD patients on POD 55. CONCLUSIONS Preoperative MELD score predicts postoperative bleeding in contemporary VADs. Preoperative liver dysfunction may also alter postoperative subclinical haemostasis through different temporal trends of thrombin generation and platelet counts, as well as protracted fibrinolysis.

Substantial Reduction in Driveline Infection Rates With the Modification of Driveline Dressing Protocol

BACKGROUND Driveline infection (DLI) is a cause of morbidity and mortality in patients with continuous-flow left ventricular assist devices (CF-LVADs). We hypothesized that an alternate dressing protocol would decrease the rate of DLIs. METHODS AND RESULTS A retrospective review of CF-LVAD implants at a single institution from January 2010 to October 2015 was conducted. Patients were divided into implants before (group 1) and after (group 2) the introduction of the new protocol on September 1, 2012. Patients were followed until death, transplantation, change in dressing type, or 2 years. 153 patients were included: 61 in group 1 and 92 in group 2. Group 1 had fewer HVADs than group 2 (27.9% vs 71.7%; P < .001) and more destination therapy, although the latter was not statistically significant (50.8% vs 34.8%; P = .118). At 24 months, the freedom from DLI was 53% in group 1 and 89% in group 2 (P = .01). Group 1 had a significantly greater risk of DLI than group 2 (incident rate ratio 3.18, 95% confidence interval 1.23-8.18; P = .016). CONCLUSIONS Dramatic improvement in freedom from DLI at 2 years was achieved with a new driveline dressing protocol. This demonstrates that DLI rates can be improved with alternate percutaneous site care techniques in CF-LVAD patients.