Shah, Palak

Introduction: Age ≥ 70 is used to exclude patients from cardiac transplantation. Elderly patients may be offered left ventricular assist device (LVAD) therapy as an alternative. It remains poorly defined how they respond to LVAD support. Hypothesis: Elderly patients have LVAD outcomes that are non-inferior to younger patients. Methods: Data on 1,149 continuous-flow LVAD recipients from May 2004 to May 2015 was pooled from the Mechanical Circulatory Support Research Network (MCSRN). Groups were assigned based on Age ≥ 70 (n = 163) and < 70 (n = 986). Results: Patients age ≥ 70 were more likely to be male (91%), have an ischemic cardiomyopathy (71%), atrial fibrillation (41%), hypertension (66%), diabetes (38%) and prior sternotomy (45%). Older patients also had a lower BMI and higher creatinine, 26.7 ± 0.4 v. 29.9 ± 0.5 and 1.46 ± 0.04 v. 1.35 ± 0.02, p < 0.05. The hazard ratio for mortality was highest in elderly patients in the early post-operative period and stabilized over time with no long-term differences in survival, p = 0.18, Figure 1a. Elderly patients had equivalent rates of device thrombosis and stroke, p = 0.47 and 0.44, Figures 1b-c. Survival free of gastrointestinal bleeding (GIB) at 1-year was 58% in elderly patients compared to 69% in younger patients, Figure 1d, p < 0.01. Multivariate cox regression revealed that age ≥ 70 was not a significant predictor of mortality (HR 0.93, 95% CI 0.69 - 1.25, p = 0.62), but pre-operative creatinine (HR 1.54, 95% CI 1.28 - 1.86, p < 0.01) and bilirubin (HR 1.2, 95% CI 1.03 - 1.4, p = 0.02) were. When age was considered a continuous variable, the HR was 1.2 (95% CI 1.07 - 1.3 per 10y, p < 0.01). Conclusions: Elderly patients, age ≥ 70, have equivalent long-term survival after LVAD implantation with similar rates of device thrombosis and stroke. Rates of GIB were higher in the elderly and this finding warrants caution when choosing anti-coagulation protocols in the elderly. Overall age ≥ 70 does not portend a poorer survival after LVAD implant.

Abstract Various risk models with differing discriminatory power and predictive accuracy have been used to predict right ventricular failure (RVF) after left ventricular assist device (LVAD) placement. There remains an unmet need for a contemporary risk score for continuous flow (CF)‐LVADs. We sought to independently validate and compare existing risk models in a large cohort of patients and develop a simple, yet highly predictive risk score for acute, severe RVF. Data from the Mechanical Circulatory Support Research Network (MCSRN) registry, consisting of patients who underwent CF‐LVAD implantation, were randomly divided into equal‐sized derivation and validation samples. RVF scores were calculated for the entire sample, and the need for a right ventricular assist device (RVAD) was the primary endpoint. Candidate predictors from the derivation sample were subjected to backward stepwise logistic regression until the model with lowest Akaike information criterion value was identified. A risk score was developed based on the identified variables and their respective regression coefficients. Between May 2004 and September 2014, 734 patients underwent implantation of CF‐LVADs [HeartMate II LVAD, 76% ( n = 560), HeartWare HVAD, 24% ( n = 174)]. A RVAD was required in 4.5% ( n = 33) of the patients [Derivation cohort, n = 15 (4.3%); Validation cohort, n = 18 (5.2%); P = 0.68)]. 19.5% of the patients ( n = 143) were female, median age at implant was 59 years (IQR, 49.4–65.3), and median INTERMACS profile was 3 (IQR, 2–3). RVAD was required in 4.5% ( n = 33) of the patients. Correlates of acute, severe RVF in the final model included heart rate, albumin, BUN, WBC, cardiac index, and TR severity. Areas under the curves (AUC) for most commonly used risk predictors ranged from 0.61 to 0.78. The AUC for the new model was 0.89 in the derivation and 0.92 in the validation cohort. Proposed risk model provides very high discriminatory power predicting acute severe right ventricular failure and can be reliably applied to patients undergoing placement of contemporary continuous flow left ventricular assist devices.

Highly specialized left ventricular assist device care is not readily available in many areas, potentially limiting access to therapy. This retrospective analysis examines the relationship of outcomes by patient distance from implanting left ventricular assist device center within the Mechanical Circulatory Support Research Network. Zip codes were used to calculate patient distance, with the primary outcome of interest being 3-year survival by distance from the surgical center. Secondary outcomes included 90-day survival and incident event rates for the following: gastrointestinal bleeding, infection, cerebral event, and pump thrombosis. Across the four centers, there were 1184 patients supported for a median of 486 days. Overall survival was 91 ± 0.8% at 90 days and 61 ± 1.9% at 3 years, with worse 3-year survival in those living >90 vs . ≤90 miles from the ventricular assist device implant center (55 ± 3.0% vs . 64 ± 2.5, p = 0.019). Patients living >90 miles from an implant center were older, more likely to be implanted for destination therapy support, had a prior sternotomy, and had worse renal function than those living closer ( p <0.05 for all). After adjusting for these factors, albumin and center of implant, the hazard ratio did not reach statistical significance (hazard ratio = 1.2; p = 0.14). Except for gastrointestinal bleeding, the event rates for the secondary outcomes were higher for those living closer to the implanting center. Protocols should be designed for more frequent follow-up and increased shared care opportunities to ensure optimal outcomes are achieved in distant patients.

Continuous-flow left ventricular assist devices (CF-LVADs) have revolutionized the management of patients with advanced heart failure. Alternative implant strategies are increasingly used for device placement. We reviewed our experience from the Mechanical Circulatory Support Research Network registry with the HeartWare centrifugal CF-LVAD (HVAD). From May 2004 to August 2015, 1,150 patients underwent primary CF-LVAD implantation at our institutions. Within this group, a total of 283 patients (25%) were implanted with the HVAD. A minimally invasive left lateral thoracotomy (MILT) implant strategy was used in 53 patients (20%), of which 22 (42%) were implanted off-pump. Median age at implant was 59 years and 183 patients (65%) were implanted as bridge-to-transplantation. Follow-up was 100% complete for a total of 302 patient-years of support. In-hospital mortality was 4.9% (14 patients), and was comparable between the conventional sternotomy (CS) and MILT cohorts (p = 0.15). Patients in the MILT cohort had a shorter median length of stay (p < 0.01) and had a lower incidence of postimplant pump thrombus (p = 0.02). Cumulative survival at the end of follow-up reached 84%, and was comparable between the two groups (p = 0.298). Multivariate analysis identified preoperative bilirubin level as the only independent predictor of survival. Surgical technique had no impact on survival. In this large, multicenter experience, data demonstrate excellent survival and adverse event profiles for patients supported with the HVAD technology, regardless of surgical implant technique. With constant advancements in device technology along with our increasing clinical experience with the newer techniques, minimally invasive LVAD implantation continues to evolve as a valuable alternative to CS in selected patients.