Outcomes in Late Right Heart Failure after LVAD:A Contemporary Analysis of the New Intermacs 4.0 Definition

Right Heart Failure Following Left Ventricular Device Implantation: Natural History, Risk Factors, and Outcomes: An Analysis of the STS INTERMACS Database

BACKGROUND

Our current understanding of right heart failure (RHF) post-left ventricular assist device (LVAD) is lacking. Recently, a new Interagency Registry for Mechanically Assisted Circulatory Support definition of RHF was introduced. Based on this definition, we investigated natural history, risk factors, and outcomes of post-LVAD RHF.

METHODS

Patients implanted with continuous flow LVAD between June 2, 2014, and June 30, 2016 and registered in the Interagency Registry for Mechanically Assisted Circulatory Support/Society of Thoracic Surgeons Database were included. RHF incidence and predictors, and survival after RHF were assessed. The manifestations of RHF which were separately analyzed were elevated central venous pressure, peripheral edema, ascites, and use of inotropes.

RESULTS

Among 5537 LVAD recipients (mean 57±13 years, 49% destination therapy, support 18.9 months) prevalence of 1-month RHF was 24%. Of these, RHF persisted at 12 months in 5.3%. In contrast, de novo RHF, first identified at 3 months, occurred in 5.1% and persisted at 12 months in 17% of these, and at 6 months occurred in 4.8% and persisted at 12 months in 25%. Higher preimplant blood urea nitrogen (ORs,1.03-1.09 per 5 mg/dL increase; P<0.0001), previous tricuspid valve repair/replacement (ORs, 2.01-10.09; P<0.001), severely depressed right ventricular systolic function (ORs,1.17-2.20; P=0.004); and centrifugal versus axial LVAD (ORs,1.15-1.78; P=0.001) represented risk factors for RHC incidence at 3 months. Patients with persistent RHF at 3 months had the lowest 2-year survival (57%) while patients with de novo RHF or RHF which resolved by 3 months had more favorable survival outcomes (75% and 78% at 2 years, respectively; P<0.001).

CONCLUSIONS

RHF at 1 or 3 months post-LVAD was a common and frequently transient condition, which, if resolved, was associated with relatively favorable prognosis. Conversely, de novo, late RHF post-LVAD (>6 months) was more frequently a persistent disorder and associated with increased mortality. The 1-, 3-, and 6-month time points may be used for RHF assessment and risk stratification in LVAD recipients.

Long-term survival in patients with post-LVAD right ventricular failure: multi-state modelling with competing outcomes of heart transplant

BACKGROUND

Multicenter data on long term survival following LVAD implantation that make use of contemporary definitions of RV failure are limited. Furthermore, traditional survival analyses censor patients who receive a bridge to heart transplant. Here we compare the outcomes of LVAD patients who develop post-operative RV failure accounting for the transitional probability of receiving an interim heart transplantation.

METHODS

We use a retrospective cohort of LVAD patients sourced from multiple high-volume centers based in the United States. Five- and ten-year survival accounting for transition probabilities of receiving a heart transplant were calculated using a multi-state Aalen Johansen survival model.

RESULTS

Of the 897 patients included in the study, 238 (26.5%) developed post-operative RV failure at index hospitalization. At 10 years the probability of death with post-op RV failure was 79.28% vs 61.70% in patients without (HR 2.10; 95% CI 1.72 - 2.57; p = < .001). Though not significant, patients with RV failure were less likely to be bridged to a heart transplant (HR 0.87, p = .4). Once transplanted the risk of death between both patient groups remained equivalent; the probability of death after a heart transplant was 3.97% in those with post-operative RV failure shortly after index LVAD implant, as compared to 14.71% in those without.

CONCLUSIONS AND RELEVANCE

Long-term durable mechanical circulatory support is associated with significantly higher mortality in patients who develop post-operative RV failure. Improving outcomes may necessitate expeditious bridge to heart transplant wherever appropriate, along with critical reassessment of organ allocation policies.

Optimal Mechanical Unloading in Left Ventricular Assist Device Recipients Relates to Progressive Up-Titration in Pump Speed

BACKGROUND

Left ventricular (LV) assist devices (LVADs) are known to elicit reverse remodeling by mechanically unloading the left ventricle. Current guidelines target a reduction in LV end-diastolic diameter (LVEDD) of 15% compared with pre-LVAD dimensions; however, there is significant heterogeneity in the degree of unloading achieved. We sought to investigate factors associated with mechanical unloading at 6 months of LVAD support.

METHODS

Data were retrospectively collected for 75 LVAD recipients at five time points: pre-LVAD, within 14 days post-LVAD, and at 1, 3, and 6 months post-LVAD. The percentage change in LVEDD between the pre-LVAD and 6 months post-LVAD time points was termed ΔLVEDD. Optimal LV unloading was defined as ΔLVEDD of ≥15% at 6 months. Patients who achieved optimal unloading (group A, n = 30) were compared with patients who did not (group B, n = 45).

RESULTS

At 6 months, optimally unloaded patients (group A) demonstrated higher fractional shortening (15% ± 10% vs 10% ± 7%, P = .007), lower rates of moderate or severe mitral regurgitation (10% vs 33%, P = .02), and lower pulmonary capillary wedge pressure (9 ± 4 vs 16 ± 7 mm Hg, P = .02). Right ventricular dysfunction was more prevalent at 6 months in poorly unloaded (group B) patients (73% vs 43%, P = .008). Between hospital discharge and 6 months, the percentage increase in pump speed (Δ revolutions per minute) was higher in group A patients (4.4% ± 3.7% vs 0.1% ± 2.6%, P < .001). In a multivariate analysis, Δ revolutions per minute and tricuspid annular systolic velocity (S') at 6 months were independently associated with 6-month ΔLVEDD.

CONCLUSIONS

Recipients of LVADs who undergo progressive pump speed up-titration during outpatient follow-up are more likely to sustain optimal LV unloading. Progressive LVAD-related right ventricular failure is prevalent in suboptimally unloaded patients.