Prolonged QTc affects short-term and long-term outcomes in patients with normal left ventricular function undergoing cardiac surgery

Definitions of low cardiac output syndrome after cardiac surgery and their effect on the incidence of intraoperative LCOS: A literature review and cohort study

Objectives

Low cardiac output syndrome (LCOS) is a serious complication after cardiac surgery. Despite scientific interest in LCOS, there is no uniform definition used in current research and clinicians cannot properly compare different study findings. We aimed to collect the LCOS definitions used in literature and subsequently applied the definitions obtained to existing data to estimate their effect on the intraoperative LCOS incidences in adults, children and infants.

Design

This is a literature review, followed by a retrospective cohort study.

Setting

This is a single-institutional study from a university hospital in the Netherlands.

Participants

Patients from all ages undergoing cardiac surgery with cardiopulmonary bypass between June 2011 and August 2018.

Interventions

We obtained different definitions of LCOS used in the literature and applied these to data obtained from an anesthesia information management system to estimate intraoperative incidences of LCOS. We compared intraoperative incidences of LCOS in different populations based on age (infants, children and adults).

Measurements and main results

The literature search identified 262 LCOS definitions, that were applied to intraoperative data from 7,366 patients. Using the 10 most frequently published LCOS definitions, the obtained incidence estimates ranged from 0.4 to 82% in infants, from 0.6 to 56% in children and from 1.5 to 91% in adults.

Conclusion

There is an important variety in definitions used to describe LCOS. When applied to data obtained from clinical care, these different definitions resulted in large distribution of intraoperative LCOS incidence rates. We therefore advocate for standardization of the LCOS definition to improve clinical understanding and enable adequate comparison of outcomes and treatment effects both in daily care and in research.

Preoperative QTc Interval is Not Associated With Intraoperative Cardiac Events or Mortality in Liver Transplantation Patients

OBJECTIVES

The primary objective of this study was to determine whether liver transplantation recipients with preoperative prolonged corrected (QTc) intervals have a higher incidence of intraoperative cardiac events and/or postoperative mortality compared with their peers with normal QTc intervals.

DESIGN

This was a retrospective cohort study.

SETTING

Single academic hospital in New York, NY.

PARTICIPANTS

Patients undergoing liver transplantation between 2007 and 2016.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Data relating to all liver transplantation recipients with preoperative electrocardiograms were queried from an institutional anesthesia data warehouse and electronic medical records. Primary outcomes were a composite outcome of intraoperative cardiac events and postoperative mortality. Patients with a prolonged QTc interval (>450 ms for men, >470 ms for women) did not demonstrate an association with intraoperative cardiac events, 30- or 90-day mortality, in-hospital mortality, or overall mortality compared with recipients in the normal QTc interval group. A prolonged QTc was found to be associated with increased anesthesia time, surgical time, length of hospital stay, and incidence of fresh frozen plasma and platelets transfusion.

CONCLUSIONS

Prolonged QTc interval is not associated with an increased incidence of intraoperative cardiac events or mortality in liver transplantation recipients. The demonstrated correlation among QTc length and Model for End-stage Liver Disease score, blood component requirements, surgical and anesthetic times, and hospital length of stay likely represents the association between QTc length and severity of liver disease.