11, 15
Control / usual care
Temporary mechanical circulatory support (VA ECMO and LV unloading devices)
Subgroup finding vulnerable to multiplicity. READ VIA SECONDARY SUMMARY (ACC journal scan) because Lancet and ScienceDirect are inaccessible; volume, pages and DOI unverified. IMPORTANT: the summary's account of the device split (611 loading / 503 unloading) alongside its statement that IABP and microaxial pumps were not specifically compared appears internally inconsistent for a nine-trial analysis - VERIFY THE DEVICE BREAKDOWN against the primary before quoting it elsewhere.
Infarct-related cardiogenic shock, pooled individual patient data from nine randomised trials of temporary mechanical circulatory support of all types. Reported split: 611 loading devices (VA ECMO), 503 left ventricular unloading devices. The nine constituent trials are NOT named in the summary read.
6-month all-cause mortality
Overall HR 0.87 (95% CI 0.74 to 1.03), p = 0.10. LV unloading devices HR 0.80 (0.62 to 1.02), p = 0.075. Loading devices HR 0.93 (0.75 to 1.17), p = 0.55. ONE positive subgroup: STEMI without risk of hypoxic brain injury, HR 0.77 (0.61 to 0.97), p = 0.024. HARMS: major bleeding increased 2.64-fold; vascular complications increased 4.43-fold. Authors' conclusion: 'MCS use should only be reserved for selected patients, i.e., patients with STEMI and CS without risk of hypoxic brain injury.'
The STEMI-without-hypoxic-brain-injury result is one subgroup among many in a pooled analysis: hypothesis-generating, not practice-defining, and it should not be quoted as licence to cannulate. Still confined to infarct-related shock. Device categorisation into 'loading' and 'unloading' is coarse and pools heterogeneous devices.
The largest and longest-follow-up synthesis in this field. Extends the negative finding to 6 months and across device types, and quantifies harm again. Its single positive subgroup is defined by SUBSTRATE and NEUROLOGICAL INTEGRITY rather than by shock severity - the key conceptual finding for patient selection, and the basis of Chapter 11's Controversy 2.