Use of a microaxial flow pump with standard care led to a lower risk for death than standard care alone in patients with ST-elevation
Eligible patients had STEMI and cardiogenic shock, defined as sustained hypotension, end-organ hypoperfusion with arterial lactate level ≥ 2.5 mmol/L, and a left ventricular ejection fraction less than 45%. Patients could be randomly assigned before, while in, or up to 12 hours after leaving the cath lab, depending on when the shock was first diagnosed.
"There was no difference in days alive out of hospital," Møller told meeting attendees. "In fact, there were more patients still in hospital at day 30 in the micro-axial flow pump group." With regard to prespecified subgroups, patients with very low blood pressure, less than the median, and those with multivessel disease seemed to benefit most.
The researchers were surprised that more patients in the mAFP group ended up on renal replacement therapy, Møller said. "We will look into whether this is device-related or could be related to survival bias."Møller stressed that "we should be cautious not to extrapolate these results to other causes of cardiogenic shock. The results may not apply to the out-of-hospital cardiac arrest patient who is comatose or the patient with non-ischemic cardiogenic shock.
The pump was effective in the current trial, he said, "because the patients were so sick that the benefit kind of overshadows the risk. But if we don't reduce the risk and start to investigate less sick patients, this will not work. The bleeding and renal function are at the top of the list of sub-studies we will be diving into.