Subtitle: A word of caution in the use of Impella in patients
with cardiogenic shock
Author: Mohammad Reza Movahed, MD, PhD 1,2,3
University of Arizona Tucson1 University of Arizona
Phoenix2
Correspondent:
M Reza Movahed, MD, PhD, FACP, FACC, FSCAI, FCCP
Clinical Professor of Medicine, University of Arizona, Tucson
Clinical Professor of Medicine, University of Arizona, Phoenix
1501 No Campbell Aven
Tucson, AZ 85724
Tel: 949 400 0091
Email: rmova@aol.com
Conflict of interest: None
Keywords: Acute coronary syndrome; cardiogenic shock; shock; cardiac
assist device; IABP; cardiac support; congestive heart failure; device
use; myocardial infarction; Impella
With great interest, I read the manuscript entitled “Comparative
Effectiveness of Percutaneous Microaxial Left Ventricular Assist Device
(MCS) vs Intra-Aortic Balloon Pump or No Mechanical Circulatory Support
in Patients With Cardiogenic Shock” in JAMA Cardiology. (1) They found
that the adjusted 30-day mortality risk post-PCI was 41.3% in the IABP
cohort which was 11.4% lower than with the use of MCS and was similar
to no device et al (difference IABP vs no device 3.1%). Their findings
were consistent even though they adjusted for every possible confounding
factor. They also avoided
acceptance that mortality was much lower in the IABP cohort in
comparison to MCS and was similar to any device use despite the fact
that most patients treated with IABP are much sicker and if IABP had no
positive effect on mortality, higher mortality suggesting a positive
effect of IABP on mortality in their patients with cardiogenic shock.
We published a preprint paper (2) pending peer review publication by
analyzing over 844,020 patients with all types of cardiogenic shocks
using the largest available Nationwide Inpatient Sample (NIS) database.
101,870 were treated with IABP and 39,645 with an Impella. Consistent
with their results, we found much higher inpatient mortality rates with
Impella use despite adjusting for over 47 confounding factors.
Regardless of the severity or any underlying condition, Impella
increased mortality in patients with acute myocardial infarction-induced
cardiogenic shock (AMICS) by approximately 30% whereas IABP reduced
mortality by over 30% regardless of severity or hospital type. The
benefit of IABP was also consistent regardless of comorbidities and also
was highly significant in comparison to no device in all subgroup
cohorts. Two meta-analyses of Impella
trials showed worse outcomes using Impella in patients with AMICS. (3,4)
Finally, using the NIS database, patients with AMICS showed
significantly higher mortality. (5) Until large randomized trials are conducted, cardiologists need to exert utmost
caution in the judiciary use of Impella and utilize it only in selected
patients until more safety data are available.
.