Citations

The Impella 5.5 is an axillary mechanical circulatory support device used in patients with cardiogenic shock, but those with small left ventricular (LV) cavities may be at risk for suction events, hemolysis, malpositioning, hypoperfusion, and LV injury. Informally accepted guidelines, extrapolated from durable LVAD studies, suggest a minimum left ventricular internal dimension in diastole (LVIDd) of 58 mm, with some clinical practices using a more stringent ≤52 mm cutoff. We retrospectively analyzed 154 consecutive patients supported with Impella 5.5 between January 2020 and December 2024. Overall, 38 patients had an LVIDd ≤58 mm, and 116 had an LVIDd >58 mm; a key subgroup of 21 patients presented with a very small LVIDd of ≤52 mm]. Baseline demographics, comorbidities, body mass index, and renal function were similar [across groups], although those with larger LVIDd had lower ejection fractions (16% vs. 24%, p = 0.001). Median support duration was 24 days in all groups, and pre- and post-implant hemodynamic and laboratory improvements were comparable. Rates of transplantation (79% vs. 90%, p = 0.088) and LVAD implantation (2% vs. 6%, p = 0.159) did not differ significantly in the ≤58 mm cohort. Notably, within the ≤52 mm subgroup, 90-day survival remained high at 90.5% ( p = 0.336), with significant improvements in right atrial pressure (17 to 10 mmHg, p = 0.041), mean pulmonary artery pressure (36 to 26 mmHg, p = 0.008), and eGFR (45 to 57 mL/min/1.73m 2 , p = 0.003). Remarkably, native cardiac recovery was observed exclusively in the smaller LV cohorts, occurring in 11% of the ≤58 mm group ( p = 0.003 vs. 0%, p = 0.003) and reaching 19% in the ≤52 mm group (vs. 0% in larger cavities, p < 0.001), while durable LVAD escalation was entirely avoided in the ≤52 mm cohort (0% vs. 6%). Ninety-day event-free survival was excellent across all cohorts 92% vs. 96% in the primary analysis, with no major device-related complications, suction events, clinically significant hemolysis, bleeding, stroke, or escalation to Bi-VAD support. These findings strongly support the safety and feasibility of Impella 5.5 in extremely constrained, small LV cavities.

Background: Impella 5.5 is a temporary MCS device FDA-approved for use up to 14 days. Limited data suggest it may be safe beyond this. We aim assess outcomes based on the duration of Impella 5.5 support in heart failure cardiogenic shock (HFCS) patients at our institution. Methods: We retrospectively reviewed all HFCS patients supported with Impella 5.5 at our institution between 2020-2024. Patients supported for >14 days were compared with those supported for ≤14 days. Categorical variables were analyzed with chi-square tests, continuous variables with t-tests or Mann-Whitney U. Logistic regression identified factors linked to clinical outcomes. Results: 154 patients were included: 38 (25%) with support ≤14 days, 116 (75%) with >14 days. Median support duration was 10 (6–12) vs 31 (22–45) days, respectively. Median support duration was 10 (6-12) days for the ≤14 cohort and 31 days (22-45) days for the >14 cohort. Baseline characteristics, comorbidities, LVEF 18% (15-23) and hemodynamics show no statistical differences. Patients supported for >14 days were more likely to undergo heart transplant compared to those supported ≤14 days (91% vs 74%, p=0.009). In contrast, myocardial recovery was more likely in the ≤14 day cohort (8% vs 1%, p=0.018). One patient suffered stroke post-transplant in the ≤14 day group and two had brachial plexus injuries in the >14 days group. Mortality during the impella-supported period was slightly higher in the ≤14 day group (8% vs 5%, p=0.535) but comparable overall, 13% in both groups, p=0.971. Support >14 days was associated with transplant outcome (OR 3.41, 95% CI 1.32–8.84, p=0.012), and remained significant after adjusting for age, gender, GFR, and EF (OR 4.05, 95% CI 1.31–12.54, p=0.015). Support duration <14 days was associated with recovery or LVAD outcomes (OR 5.01, 95% CI 1.49–16.89, p=0.009), and remained significant after adjustment (OR 5.43, 95% CI 1.11–26.45, p=0.036). No association was observed between duration of support and LVAD/mortality outcomes or with EcPella use. Conclusion: Shorter Impella support duration was independently associated with early myocardial recovery or LVAD candidacy, likely reflecting rapid clinical decision-making. Prolonged Impella support was associated with increased likelihood of transitioning to heart transplantation, likely reflecting clinical stabilization over time. Our multidisciplinary, single-center data suggests Impella 5.5 can be used beyond FDA-approved 14 days in HFCS patients.

Background: Renal dysfunction is a known prognostic factor in advanced heart failure and among patients receiving temporary mechanical circulatory support (tMCS). However, the predictive value of post-Impella creatinine in determining healthcare resource utilization in patients bridged to transplant with Impella 5.5 remains unclear. This study aimed to evaluate the association between post-Impella creatinine and key hospitalization metrics in this population. Methods: We performed a retrospective cohort study of patients who received Impella 5.5 as a bridge-to-transplant between January 2020 and January 2025. Serum creatinine was collected 72 hours after Impella placement. The primary outcome was device-to-discharge time. Secondary outcomes included transplant-to-discharge time, post-transplant ICU length of stay (LOS), and total LOS (admission-discharge). Univariate and multivariable linear regressions were used to examine the association between post-Impella creatinine and each outcome, adjusting for age, gender, BMI, and LVEF. Results: 133 patients were supported with the Impella 5.5 as BTT and were included (median age 58 years (51–65), 82.7% were male, and 71.4% presented with non-ischemic cardiomyopathy. The median BMI was 27.7 (24.3–32.3), LVEF 17% (15–22), and post-Impella creatinine 1.32 mg/dL (0.96–1.71). The median device-to-discharge time was 45 days (29-64), transplant-to-discharge time was 14 days (12–19), ICU LOS post-transplant was 6 days (4–8), and total LOS was 58 days (42–76). Higher post-Impella creatinine was significantly associated with longer device-to-discharge time (β = 6.67, p = 0.004), longer transplant-to-discharge duration (β = 3.42 p = 0.003), longer ICU LOS (β = 2.19, p = 0.007), and longer total LOS (β = 7.24, p = 0.002) on univariate analysis. Post-impella creatinine remained significantly associated with device-to-discharge time in the multivariate model after adjusting for confounders (β = 6.33, p = 0.006). Importantly, this suggests that patients with lower post-Impella creatinine levels may experience shorter hospitalizations and faster recovery trajectories following transplant. Conclusions: Post-Impella creatinine is a significant predictor of prolonged hospitalization in patients supported with Impella 5.5 as a bridge to transplant. These findings emphasize the prognostic importance of early renal function assessment and may guide risk stratification and resource planning in advanced heart failure care.

Background: Progressive heart failure cardiogenic shock (HFCS) often requires escalation to temporary or durable mechanical circulatory support (MCS) as a bridge to transplant (BTT). Following the 2018 UNOS allocation changes, our center revised its BTT strategy to optimize support and shorten wait times. At our institution, the Impella 5.5 with SmartAssist via the axillary approach was selectively used for patients who remained refractory to guideline-directed medical therapy, failed single-inotrope therapy, and were not considered suitable durable LVAD candidates by our multidisciplinary heart team. We compared transplant-related outcomes of BTT patients supported with Impella 5.5 versus durable LVAD. Methods: We performed a single-center retrospective review of all heart and heart/kidney transplant candidates at Mayo Clinic Florida from October 2018 to February 2021. INTERMACS profile, baseline characteristics, and perioperative data were collected at the time of device implantation and throughout the transplant hospitalization. Results: A total of 87 heart and 4 heart–kidney transplants were completed. Forty-five patients (49%) required MCS as BTT: 27 (60%) with a durable LVAD and 18 (40%) with an Impella 5.5. All eighteen patients with Impella 5.5 as BTT (100%) were transplanted compared to nineteen patients with durable LVAD (70%), p = 0.001. The median time from listing to transplant was substantially shorter with Impella (32 vs. 696 days, p < 0.001), and this difference persisted across INTERMACS profiles. UNOS status at transplant was more urgent for Impella than LVAD (p < 0.001). Transplant surgery following Impella support required shorter cardiopulmonary bypass time (181 vs. 219 min, p < 0.001) and resulted in lower postoperative vasoactive-inotropic requirements (7.9 vs. 13, p = 0.003). No patients in the Impella group died or were delisted while awaiting transplant, whereas 5 LVAD patients (26%) died or were removed due to LVAD complications (p < 0.001). Conclusions: Our data demonstrates that the use of the Impella 5.5 as BTT was associated with significantly shorter waitlist time, higher transplantation rates, reduced perioperative morbidity, and lower postoperative vasoactive support compared with durable LVAD as BTT. These benefits were achieved despite a higher severity of illness at transplantation in the Impella cohort.