Abstract Body (Do not enter title and authors here):
Background:
Frailty and sarcopenia are important predictors of outcomes in advanced heart failure. However, their prognostic value in patients with cardiogenic shock (CS) supported with Impella 5.5 has not been well defined. Psoas Muscle Index (PMI) is a promising metric of sarcopenia. In particular, the relationship between PMI and the likelihood of achieving native heart survival—ability to be weaned from temporary support without transition to LVAD or transplant—remains unclear.
Objectives:
To evaluate whether PMI, a marker of sarcopenia, is associated with in-hospital outcomes among CS patients treated with Impella 5.5.
Methods:
We conducted a retrospective cohort study of patients with CS supported by Impella 5.5 at a single tertiary center. Patients were categorized into three clinical outcome groups: (1) in-hospital death, (2) bridge to left ventricular assist device (LVAD), and (3) native heart survival. Patients supported by Impella 5.5 who ultimately received heart transplant were excluded due to limited data. PMI was calculated from computed tomography imaging of the chest obtained within 48 hours of admission. Axial slices at the level of the first lumbar vertebra (L1) were used to measure the cross-sectional area of the right and left psoas muscles. PMI was calculated using the formula: (Right Psoas Area + Left Psoas Area) / [Height in meters^2].
Results:
A total of 134 patients were included: 47 died during hospitalization, 30 were bridged to LVAD, and 57 achieved native heart survival. PMI differed significantly across groups (ANOVA p < 0.000001). Patients with native heart survival had the highest PMI (mean ± SD: 1.61 ± 0.69), significantly greater than those who died (0.94 ± 0.46, p < 0.000001) and those bridged to LVAD (1.19 ± 0.43, p = 0.0028). Additionally, bridge to LVAD patients had significantly higher PMI than those who died (p = 0.0085). Patients with PMI below 1 had significantly higher odds of in-hospital death compared to those with PMI ≥ 1, with an odds ratio of 7.87 (95% CI: 3.56–17.43).
Conclusions:
Higher PMI was significantly associated with native heart survival in patients with CS supported by Impella 5.5. Patients who survived without escalation to durable mechanical support had the highest PMI, while non-survivors had the lowest. A PMI below 1 was associated with an 8-fold increase in odds of in-hospital death, highlighting its potential utility as a noninvasive tool for early risk stratification in this high-risk population.