S. McKellar

Clinical and histopathological effects of heart failure drug therapy in advanced heart failure patients on chronic mechanical circulatory support

Adjuvant heart failure (HF) drug therapy in patients undergoing chronic mechanical circulatory support (MCS) is often used in conjunction with a continuous‐flow left ventricular assist device (LVAD), but its potential impact is not well defined. The objective of the present study was to examine the effects of conventional HF drug therapy on myocardial structure and function, peripheral organ function and the incidence of adverse events in the setting of MCS.

Changes in Metabolic Substrate Utilization and Pyruvate Mitochondrial Oxidation Mismatch during Mechanical Unloading of the Failing Human Heart: Implications for Cardiac Reloading and Conditioning

s S57 December 2014. Endpoints were incidence of transplantation, waitlist dropout for death or medical worsening, and post-transplant death. Grafts were allocated by simulation to patients according to blood type, morphological and age matching and CRS value, with national sharing. Simulated and historical cumulative incidences of events were compared using a competing risk model for WL events and a Cox model for post transplant death. Results: nCAS significantly decreases the overall mortality from the placement on the waiting list and improves both pre and post transplant patient outcomes. In reducing the transplant access rates gap between High Urgency (HU) and non HU patients, it also provides more equitable dropout risks. Conclusion: A patient-based allocation system including a CRS with objective criteria would correct the excess of positive discrimination for HU patients, providing more equitable results and a very promising alternative to our current CAS. Its combination to a national sharing of all organs would also decrease both WL and post transplant mortality, providing a « just in time » heart allocation for all candidates, improving both efficacy and efficiency.

Magnitude and Time Course of Changes Induced by Continuous-Flow Left Ventricular Assist Device Unloading in Chronic Heart Failure: Insights into Cardiac Recovery

Purpose The magnitude, timeline and sustainability of changes induced by continuous-flow left ventricular assist device (CF-LVAD) unloading on the structure and function of the failing human heart are unknown. Methods and Materials Eighty consecutive patients with chronic heart failure requiring CF-LVAD implantation were prospectively enrolled. Serial echocardiograms (1, 2, 3, 4, 6, 9 and 12 months) were performed after implant to evaluate the longitudinal effects of CF-LVADs on myocardial structure and function. Cardiac recovery was assessed on the basis of improvement in systolic and diastolic function indices that were sustained during LVAD turn-down studies. Results After 6 months of LVAD unloading, 22% of patients had an LVEF of 30-39% and 19% achieved an LVEF≥40% ( Figure ). In those with an LVEF≥40%, LV systolic function improved as early as 30 days, the greatest degree of improvement was achieved by 6 months and persisted over the 1-year follow-up ( Figure , panel C). LV diastolic function also improved as early as 30 days and this improvement persisted over time. LV end-diastolic and end-systolic volumes decreased as early as 30 days post-implant (120±39 vs. 82±36xa0ml/m2, p Conclusions CF-LVAD unloading induced in a subset of patients, both ischemic and nonischemics, early improvement in myocardial structure and systolic and diastolic function that was largely completed within 6 months, with no evidence of subsequent regression.

QRS and QT Interval Changes and Ventricular Arrhythmias Following Continuous Flow Mechanical Unloading of the Failing Human Heart

Purpose The effect of continuous flow left ventricular assist devices (CF-LVAD) on the arrhythmogenicity of the failing heart is a controversial issue. We sought to investigate the association of CF-LVAD unloading on the electrical properties of the failing heart including the incidence of sustained ventricular tachycardia (VT)/ ventricular fibrillation (VF). Methods and Materials The records of 80 CF-LVAD patients from the UTAH Cardiac Transplant Program implanted between 2008 and 2011 were retrospectively reviewed. 12-lead ECGs and ICD interrogations were reviewed. We examined 12 lead ECGs for QRS and QT intervals before, 4 and 12 weeks after CF-LVAD implant. ICD recording episodes of VT and VF were checked before and after LVAD implantation. Results The average age was 55±15 years (75% males) and 53% had non-ischemic cardiomyopathy. The QRS duration was found to be decreased at 4 weeks following CF-LVAD implant and this decrease was sustained at 12 weeks (Table). The QT interval also decreased at 4 and 12 weeks (Table). QRS and QT changes were observed in patients with both paced (n=43; 68.3%) and normal ventricular activation. Twenty eight patients had a history of sustained VT/VF pre CF-LVAD. Twenty one patients had VT/VF episodes following CF-LVAD implant; 8 patients presented with de novo arrhythmias. The majority of ventricular arrhythmias were monomorphic VTs (66.7%); 4 (50%) occurred in the first 4 weeks, while 4 (50%) occurred 4-12 weeks following CF-LVAD. Conclusions Chronic CF-LVAD unloading is associated with shortening of QRS and QT intervals. Ventricular arrhythmias occurred de novo following surgery despite those changes. Further studies are needed to understand the effect of unloading on the ventricular arrhythmogenic milieu and substrate. 4 Weeks post 12 weeks post Pre-LVAD LVAD LVAD P value QT 155±37xa0ms 128±34xa0ms 120±41xa0ms * QRS 446±62xa0ms 409±77xa0ms 404±78xa0ms * * Pre-LVAD to 4 weeks post LVAD