Older patients with STEMI-related cardiogenic shock have a greater risk of mortality and may not experience the same benefit from microaxial flow pump (mAFP) treatment as their younger counterparts, according to an exploratory secondary analysis of the DanGer Shock trial presented at AHA 2024 and simultaneously published in JACC.

Anika Klein, MD, et al., assessed 355 adult patients with STEMI-related cardiogenic shock randomized to receive mAFP treatment plus routine care or routine care alone. The study's primary outcome was 180-day all-cause mortality. Median patient age from lowest to highest quartile was 54, 65, 73 and 81 years with no differences in blood pressure, LVEF or shock severity across age groups.

Results showed that mortality rate increased as age increased (from lowest to highest quartile: 31%, 47%, 61% and 73%; log-rank p<0.001). Patients in the highest age quartile when compared to the lowest had an adjusted odds ratio (OR) for death of 7.85 (95% CI, 3.37-19.2; p<0.001) at 180 days.

Patients younger than 77 years randomized to the mAFP treatment group saw a reduced risk of mortality (OR, 0.45; 95% CI, 0.28-0.73; p=0.001) when compared to the control group, while patients aged 77 years or older did not (OR, 1.52; 95% CI, 0.57-4.08; p=0.40).

The authors found higher rates of complications such as moderate or severe bleeding events, limb ischemia, sepsis, and the need for renal replacement therapy in the mAFP treatment group. Complication rates were similar across age quartiles for both treatment and control groups.

"Despite the overall survival benefit observed in DanGer Shock, treatment with a mAFP was associated with a high risk of serious complications," state the authors. "Patients of advanced age may have a lower tolerance for such complications due to decreased physiologic reserves and overall frailty, potentially reducing their likelihood of benefitting from the treatment, tipping the balance from benefit towards harm."