The incidence of myocardial injury following post-operative Goal Directed Therapy

Abstract

Background: Studies suggest that Goal Directed Therapy (GDT) results in improved outcome following major surgery. However, there is concern that pre-emptive use of inotropic therapy may lead to an increased incidence of myocardial ischaemia and infarction.

Methods: Post hoc analysis of data collected prospectively during a randomised controlled trial of the effects of post-operative GDT in high-risk general surgical patients. Serum troponin T concentrations were measured at baseline and on day 1 and day 2 following surgery. Continuous ECG monitoring was performed during the eight hour intervention period. Patients were followed up for predefined cardiac complications. A univariate analysis was performed to identify any associations between potential risk factors for myocardial injury and elevated troponin T concentrations.

Results: GDT was associated with fewer complications, and a reduced duration of hospital stay. Troponin T concentrations above 0.01 microg l-1 were identified in eight patients in the GDT group and six in the control group. Values increased above 0.05 microg l-1 in four patients in the GDT group and two patients in the control group. There were no overall differences in the incidence of elevated troponin T concentrations. The incidence of cardiovascular complications was also similar. None of the patients, in whom troponin T concentrations were elevated, developed ECG changes indicating myocardial ischaemia during the intervention period. The only factor to be associated with elevated troponin T concentrations following surgery was end-stage renal failure.

Conclusion: The use of post-operative GDT does not result in an increased incidence of myocardial injury.

Figure 1

Post-operative troponin T measurements in patients randomised to the Control and Goal Directed Therapy (GDT) groups.

Figure 2

Haemodynamic data for goal directed therapy and control groups during the intervention period. Significant differences between groups: heart rate, stroke volume (both p < 0.0001, repeated measures ANOVA) but not mean arterial pressure (p = 0.87). Red squares: GDT group, Blue circles: control group. Data presented as mean (SD).