Treating Older Patients in Cardiogenic Shock with a Microaxial Flow Pump: Is it DANGERous?

Background

Whether age impacts the recently demonstrated survival benefit of microaxial flow pump (mAFP) treatment in patients with ST-segment elevation myocardial infarction (STEMI) and cardiogenic shock (CS) is unknown.

Objectives

The purpose of this study was to assess the impact of age on mortality and complication rates in patients with STEMI-related CS randomized to standard care or mAFP on top of standard care.

Methods

This is a secondary analysis of the Danish-German Cardiogenic Shock (DanGer Shock) trial, an international, multicenter, open-label trial, in which 355 adult patients with STEMI-related CS were randomized to receive a mAFP (Impella CP) plus standard care or standard care alone. The primary outcome of 180-day all-cause mortality is analysed according to age and intervention.

Results

From lowest to highest age quartile, the median ages (range) were: 54 (31-59), 65 (60-69), 73 (70-76), and 81 (77-92) years. There were no differences in blood pressure, lactate level, left ventricular ejection fraction or shock severity at randomization across age groups.Mortality increased from lowest to highest quartile (31%, 47%, 61%, and 73%, respectively; log-rank p<0.001), with an adjusted odds ratio (OR) for death at 180 days of 7.85 (95% CI, 3.37-19.2; p<0.001) in the highest quartile compared to the lowest. The predicted risk of mortality was higher in the standard-care group until approximately 77 years, after which the predicted risk became higher in the mAFP group (p-interaction=0.2). In patients younger than 77 years, a reduced 180-day mortality was observed in patients randomized to the mAFP (OR, 0.45; 95% CI, 0.28-0.73; p=0.001), opposed to patients aged 77 years or older (OR, 1.52; 95% CI, 0.57–4.08; p=0.40), p=0.028 for interaction. Complications were more frequent in the mAFP group, but there were no apparent differences in incidence of complications across all ages.

Conclusions

This exploratory secondary analysis of the DanGer Shock trial demonstrates that elderly patients with STEMI-related CS experience high mortality and may not attain the same benefit from routine treatment with a mAFP as younger patients. Incorporating age as a factor in patient selection may enhance the overall benefit of this therapy. (DanGer Shock, NCT01633502)