Predictors of 30-day mortality in patients with refractory cardiogenic shock following acute myocardial infarction despite a patent infarct artery
Received 30 March 2009; accepted 10 August 2009.
Background
Little is known about predictors of survival in patients with persistent shock following acute myocardial infarction (MI) despite a patent infarct artery.
Methods
We examined data from TRIUMPH, a multicenter randomized clinical trial of the nitric oxide synthase inhibitor, l-NG-monomethyl-arginine, in patients with persistent vasopressor-dependent cardiogenic shock complicating acute MI at least 1 hour after established infarct-related artery patency. Patients who died within 30 days were compared with those who survived. Continuous variables were assessed using the Wilcoxon rank sum and categorical variables using the χ2 test. Prespecified baseline variables were included in a multivariable logistic regression model to predict mortality. A second model incorporating baseline vasopressors and dosages and a third model including change in systolic blood pressure at 2 hours were also developed. Bootstrapping was used to assess the stability of model variables.
Results
Of 396 patients, 180 (45.5%) died within 30 days. Systolic blood pressure (SBP), measured on vasopressor support, and creatinine clearance were significant predictors of mortality in all models. The number of vasopressors and norepinephrine dose were also predictors of mortality in the second model, but the latter was no longer significant when change in SBP at 2 hours was added as a covariate in the third model.
Conclusions
The SBP, creatinine clearance, and number of vasopressors are significant predictors of mortality in patients with persistent vasopressor-dependent cardiogenic shock following acute MI despite a patent infarct artery. These prognostic variables may be useful for risk-stratification and in selecting patients for investigation of additional therapies.
aUniversity of North Carolina School of Medicine, Chapel Hill, NC
Reprint requests: Jason N. Katz, MD, 160 Dental Circle, 6th floor Burnett-Womack Building, UNC Center for Heart and Vascular Care, CB#7075, Chapel Hill, NC 27599-7875.
Marc A. Pfeffer, MD, PhD served as guest editor on this manuscript.
ABSTRACT