The use of an intravascular microaxial left ventricular assist device (LVAD) was found to be associated with increased risks for in-hospital mortality and bleeding compared with the use of an intra-aortic balloon pump (IABP) during percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) complicated by cardiogenic shock, according to study results published in JAMA.
For individuals requiring mechanical circulatory support intravascular microaxial LVADs allow for better hemodynamic support compared with IABPs.
In this registry-based propensity-matched retrospective cohort study, the data of 28,304 participants (mean age, 65.0±12.6 years; 67.0% men) from 2 American College of Cardiology National Cardiovascular Data registries were examined. Study participants had had an AMI complicated by cardiogenic shock (81.3% with ST-elevation; 43.3% with cardiac arrest) and underwent PCI with mechanical circulatory support between October 2015 and December 2017. There were 1680 propensity-matched pairs, with patients with LVAD and IABP patient who were matched on multiple variables, including coronary anatomy, infarct location, initial presentation, demographics, clinical history, and laboratory data.
The exposure in this study was the hemodynamic support type: IABP only, intravascular microaxial LVAD only, medical therapy only, or “other” (alternate systems or a combination of mechanical circulatory support devices). The primary endpoints were death and major bleeding while in the hospital.
Intravascular microaxial LVAD and IABP devices were used in 6.2% (n=1768) and 29.9% (n=8471) of patients, respectively. A total of 16,227 patients (57.3%) received only medical therapy, and 1838 patients (6.5%) had alternate devices or a combination used.
The risks for in-hospital mortality and major bleeding were found to be higher in patients on whom the intravascular microaxial LVAD was used compared with the IABP (mortality: (45.0% vs 34.1%, respectively; absolute risk difference [ARD], 10.9%; 95% CI, 7.6-14.2; P <.001; bleeding: 31.3% vs 16.0%, respectively; ARD, 15.4%; 95% CI, 12.5-18.2; P <.001). The timing of device placement (before vs after PCI initiation) did not have an effect on these associations.
Study limitations include a reliance on site documentation to determine the occurrence of cardiogenic shock, a lack of detailed clinical and hemodynamic data, and the inability to distinguish between different LVADs.
“Taken together, these results highlight the need for additional data to guide the optimal management of AMI complicated by cardiogenic shock in general and the role of MCS devices, in particular,” noted the authors. They recommended that future research closely examine clinical populations to optimize device selection for patients.
Funding for this research was provided by a Center of Excellence in Regulatory Science and Innovation (CERSI) grant to Yale University and Mayo Clinic from the FDA (U01FD005938).
Dhruva SS, Ross JS, Mortazavi BJ, et al. Association of use of an intravascular microaxial left ventricular assist device vs intra-aortic balloon pump with in-hospital mortality and major bleeding among patients with acute myocardial infarction complicated by cardiogenic shock. JAMA. 2020;323(8):734-745. doi:10.1001/jama.2020.0254