Blood pressure monitoring gaps in patients with left ventricular assist devices presenting for non-cardiac surgeries.

Study Objective: The hemodynamic assessment of patients with left ventricular assist devices (LVAD) using noninvasive blood pressure (NIBP) monitoring may be unreliable without pulsatile blood flow. The primary goal of this study is to examine the association between intraoperative blood pressure monitoring gaps of 10 min or greater and LVAD type in patients undergoing noncardiac surgeries with NIBP monitors at induction.

Design: Retrospective cohort.

Setting: Single institution, academic university hospital.

Participants: One-hundred fifteen patients undergoing 187 noncardiac surgeries without arterial lines at induction.

Interventions: Noncardiac surgery.

Measurements: The primary outcome was the association of blood pressure monitoring gaps, which were defined as ten minutes or greater, and LVAD type including the HeartMate 2 (HM2; Abbott, Chicago, IL) and the HeartMate 3 (HM3; Abbott, Chicago, IL), as evaluated by multivariable logistic regression analysis.

Main Results: After adjusting for patient characteristics, HM3 was associated with lower odds of monitoring gaps (p = 0.02). Additionally, the odds of a monitoring gap were higher in patients with morbid obesity (p = 0.04) and in surgical duration longer than 180 min (p = 0.001). In the post-hoc analysis, morbid obesity, general anesthesia, and prolonged surgeries were found to be associated with increased odds of arterial line placement after induction (p = 0.05, p = 0.007, p < 0.001).

Conclusions: Patients with a HM2 undergoing noncardiac surgery had nearly three-fold higher odds of blood pressure monitoring gaps of 10 min or greater compared to patients with a HM3. Morbid obesity and prolonged surgical duration were also associated with a significant increase in monitoring gaps. Morbid obesity, general anesthesia, and longer surgical duration were found to have a greater odds of arterial line placement after induction. These results may help anesthesiologists determine the appropriateness of NIBP in patients with LVADs undergoing noncardiac surgeries.