A simple risk chart for initial risk assessment of 30-day mortality in patients with cardiogenic shock from ST-elevation myocardial infarction

Abstract

Aims:

Early risk stratification is important in patients with cardiogenic shock from ST-elevation myocardial infarction (STEMI). We aimed to develop a simple risk chart that includes clinical parameters that are readily available at time of hospital admission to assess risk of 30-day mortality.

Methods and results:

A series of 544 STEMI patients admitted to undergo primary percutaneous coronary intervention and presenting with cardiogenic shock were included between 2000 and 2012. Overall 30-day mortality was 38.4% and did not change over the years (p-trend=0.64). Baseline variables that were available at time of hospital admission were entered into a logistic regression model in a forward stepwise manner. Only age (odds ratio (OR) per year 1.05, 95% confidence interval (CI) 1.04–1.07, p<0.001), initial serum lactate level (OR per mmol/l 1.17, 95% CI 1.11–1.24, p<0.001) and initial creatinine level above the upper limit of normal (OR 2.89, 95% CI 1.90–4.37, p<0.001) remained independent predictors, and were subsequently used to develop a risk chart that stratifies risk of 30-day mortality into categories ranging from 0–20% to 80–100%. The calibration plot showed a close relationship between expected and observed mortality. The risk chart had a higher discriminative accuracy than the GRACE score (c-index 0.75 vs. 0.66, p=0.009). Adding variables that were obtained from coronary angiography and during clinical course did not significantly improve discriminative accuracy of risk chart (c-index 0.77, p=0.48).

Conclusion:

Mortality of patients with cardiogenic shock from STEMI undergoing primary percutaneous coronary intervention can be well predicted already at time of hospital admission by a risk chart that uses only three variables, namely, age, initial serum lactate and creatinine level.