Left Ventricular Device Patients Research Articles

(759) Stroke and Survival Outcomes in Left Ventricular Device Patients

(759) Stroke and Survival Outcomes in Left Ventricular Device Patients

Cerebral Microvascular Injury in Patients with Left Ventricular Assist Device: a Neuropathological Study.

Strokes are common among patients with left ventricular devices (LVAD). We hypothesize that there is ongoing cerebral microvascular injury with LVAD support and aim to describe this among LVAD-implanted patients through post-mortem neuropathologic evaluation. We identified and reviewed medical records of LVAD patients who underwent brain autopsy between January 2006 and December 2019 at a tertiary center. Cerebral injury was defined as both gross and microscopic injuries within the intracranial space including cerebral infarct (CI), hypoxic-ischemic brain injury (HIBI), intracranial hemorrhage (ICH), and cerebral microvascular injury. Cerebral microvascular injury was defined as microscopic brain intraparenchymal or perivascular hemorrhage, perivascular hemosiderin deposition, and perivascular inflammation. Twenty-one patients (median age = 57years, 67% male) had autopsy after LVAD support (median LVAD support = 51days). The median time from death to autopsy was 19h. All 21 patients had cerebral injuries and 19 (90%) patients had cerebral microvascular injuries. Fourteen patients (78%) harbored more than one type of cerebral injury. On gross examination, 8 patients (38%) had CI, and 6 patients (29%) had ICH. On microscopic exam, 12 patients (57%) had microscopic intraparenchymal hemorrhage, 3 patients (14%) had perivascular hemorrhage, 11 patients (43%) had perivascular hemosiderin deposition, 5 patients (24%) had meningeal hemorrhage, 13 patients had chronic perivascular inflammation (62%), and 2 patients had diffuse HIBI (10%). Among patients with LVAD, there is a high prevalence of subclinical microvascular injuries and cerebral microbleeds (CMBs), which may provide some insights to the cause of frequent cerebral injury in LVAD population.

Antithrombotics after Intracranial Hemorrhage in Patients with Left Ventricular Assist Devices

Decisions regarding if or when to resume antithrombotics (anticoagulation or antiplatelets) after intracranial hemorrhage (ICH) in patients with left ventricular devices (LVADs) remain controversial and available data to guide management is limited. We aim to explore antithrombotic practices following ICH in LVAD patients and identify most effective strategies. Using a retrospective analysis of our institutional LVAD database between 11/2012 and 5/2018, we identified all patients who suffered ICH. We recorded type and timing of antithrombotic resumed following ICH. Primary outcome events included subsequent ischemic stroke or TIA, pump thrombosis, systemic thrombosis, re-hemorrhage, and extracranial bleeding; death was a secondary outcome. Other variables collected included age, sex, and year of LVAD placement. Descriptive and nonparametric survival analyses were performed. A total of 36 adult patients met our criteria. Median age was 54.5 years (IQR 38-56), 28% were women, and 25% non-white. Forty-four percent of procedures occurred after 2014 and ICH occurred a median of 266 days (IQR 110-689) after LVAD implantation. Antiplatelets were held in 83% of patients for a median duration of 20 days (IQR 5.5 days to never restarted) and anticoagulation held in 92% for a median of 5 days (IQR 3-27). After ICH, 19 patients suffered 25 outcome events including 19 primary events (3 ischemic strokes/TIAs, 3 pump thromboses, 4 systemic thrombotic events, 7 re-hemorrhage, and 2 systemic hemorrhages). Kaplan-Meier survival free of a primary outcome was 89%, 72% and 58% at 7, 14 and 30 days post-ICH, respectively. Most of the 36 patients died (n=26, 72%), 12 within 90 days of the index ICH. There were no significant associations between survival free of a primary event and timing of anticoagulation, age > 60, sex, or LVAD placement before vs after 2014. Ischemic and hemorrhagic complications occurred at similar, high rates following intracranial hemorrhage in LVAD patients, with no evidence of increased risk of re-hemorrhage with early anticoagulation. Future study is necessary to identify specific risk factors for rebleeding and re-thrombosis in these patients to reduce levels or morbidity and mortality following intracranial hemorrhage.

New Insights into Right Ventricular Function among Patients with Left Ventricular Assist Devices Using High Fidelity Conductance Catheters to Generate Real Time Pressure Volume Loops

Purpose Determine the impact of continuous-flow (CF) left ventricular devices (LVADs) on resting and exertional right ventricular (RV) performance. Methods Eight LVAD patients (all male, 57±8yrs) with normal resting RV function completed invasive hemodynamic assessment during submaximal (mild and moderate, defined by rate of perceived exertion score of 7-9, and 11-13, respectively), and peak exercise on an upright cycle ergometer, and up- and downward pump speed adjustments under supine resting conditions. Results were compared with 7 healthy controls (HC, five males, 37±10yrs). Results Compared to HC, CF-LVAD patients had a lower cardiac output (Qc), oxygen uptake (VO2), and heart rate (HR) at submaximal and peak exercise. Analysis of RV PV loops during exercise testing (Figure 1A-B, and Table 1) shows that RV contractility (Starling contractile Index and DP/DT) was greater, and RV relaxation (-DP/DT), was less than HC during all exercise stages. Among CF-LVAD patients, peak Qc was lower, and DP/DT was similar to, values observed among HC at mild exercise (ie, a similar workload). Changes in pump speed were not associated with any significant change in RV contractility, relaxation, RV end-diastolic pressure, or myocardial energetics (Figure 1C). Conclusion RV function among CF-LVAD patients is characterized by reduced metrics of contractility and relaxation and lower cardiac output compared to healthy individuals exercising at similar workloads. Up- and downward changes in pump speed had minimal impact on resting RV performance.

Impact of Concomitant Valvular Surgery on Patients Undergoing LVAD Implantation

Purpose Concomitant valvular surgery at the time of left ventricular device (LVAD) implantation remains controversial. This study aims to evaluate outcomes of these patients compared to the isolated-LVAD cohort. Methods We examined 309 adult LVAD patients (2009-2018) at Stanford and identified those who underwent concomitant aortic, mitral, or tricuspid valve surgery. Pre- and post-operative data were analyzed and compared with those who underwent LVAD implantation alone. We also performed a case-control study to compare the concomitant valve-LVAD patients to those with ≥ 3+ or 4+ regurgitation (moderate and severe, respectively) who only received an LVAD. Continuous variables were analyzed using student's t test and reported as mean ± standard deviation (SD), and Wilcoxon rank-sum test with median and 1st and 3rd quartile values (Q1 and Q3). Categorical variables were analyzed using Fisher's exact test (n, %). All p-values are two tailed with Results Twenty-two patients had valvular intervention at the time of LVAD placement: 10 aortic, 11 tricuspid, and 1 mitral. Preop demographics were similar across all groups. Expectedly, intraop data showed that patients with concomitant valve surgery had greater cardiopulmonary bypass (CPB) time than those without valve surgery. They also had higher rates of OR take-backs for bleeding, tracheostomy, dialysis, post-op stroke, and overall mortality. Furthermore, patients undergoing both LVAD-TVR and LVAD-AVR subsets had longer CPB time, but the LVAD-TVR group alone was at higher risk for bleeding, tracheostomy, dialysis, longer hospital stay, and lower overall survival. (Table 1 does not include LVAD-AVR and MVR data.) Conclusion Patients undergoing concomitant valve surgery at time of LVAD placement have higher risk for increased complications and mortality when compared to the isolated-LVAD cohort. However, these risks are more apparent only in patients undergoing LVAD-TVR and not in the LVAD-AVR or MVR cohorts.

T-Cell Response to Staphylococcal Enterotoxin B Is Reduced Among Heart Failure Patients on Ventricular Device Support

Infections are the major complication among patients on left ventricular device (LVAD) support. One mechanism that may explain the elevated incidence of infection is a deficiency in cellular immunity after LVAD placement. To test this hypothesis, we evaluated the in vitro T-cell–proliferative and cytokine response following challenge with staphylococcal enterotoxin B in 14 LVAD and 6 non-LVAD stable outpatients awaiting heart transplantation. Clinical outcome was followed for 12 months. Clinical outcome was poorer ( P < .05) for LVAD vs non-LVAD patients. T-cell–proliferative response was lower ( P = .002) for LVAD vs non-LVAD patients. Th1 cytokine expression was lower ( P < .05) and Th2 cytokine expression was higher ( P < .05) for LVAD vs non-LVAD patients. We conclude that LVAD recipients are hyporesponsive to superantigen challenge, indicating a depressed cellular immunity that may contribute to their increased susceptibility to infections.