Abstract 3495: Improvement in Stroke Work Index and Stroke Volume Index, the Most Powerful Serial Hemodynamic Variables in Cardiogenic Shock Complicating Acute Myocardial Infarction, Should not Delay Early Revascularization: A Report from the SHOCK Trial
Background: In cardiogenic shock (CS), conclusive data on the prognostic value of serial hemodynamic measurements are lacking.
Methods: The SHould we emergently revascularize Occluded Coronaries for cardiogenic shocK? (SHOCK) Trial (n=294) tested emergency revascularization (ERV) compared with initial medical stabilization (IMS) and assessed hemodynamic variables by pulmonary artery catheterization (PAC). Measured and derived variables included heart rate, blood pressure, pulmonary capillary wedge pressure (PCWP), cardiac index, cardiac power index, stroke volume index (SVI), stroke work index (SWI), left ventricular work index, and right-sided pressures.
Results: Baseline hemodynamic data were available in 278 (95%) and follow-up data in 174 (66%) of alive patients with predominant left ventricular failure. Baseline and follow-up hemodynamic values were not different between ERV and IMS (baseline 3.3 vs. 3.3 hrs, p=ns, and follow-up 12.5 vs. 10.6 hrs from CS diagnosis, p=0.043). Baseline SVI [(cardiac output/heart rate) x 1000/body surface area] was an independent predictor of 30-day mortality after adjustment for age (odds ratio 0.69 per 5 ml/m2 increase, 95% confidence interval 0.55–0.87; p=0.002). At follow-up and after adjustment for age, both SWI [(mean arterial pressure-pulmonary artery wedge pressure) x stroke volume x 0.0136/body surface area] and SVI were similarly powerful predictors of 30-day mortality (odds ratios 0.54 per 5 g/m/m2 increase, 95% confidence interval 0.39–0.76; p<0.001 and 0.59 per 5 ml/m2 increase, 95% confidence interval 0.45–0.77; p<0.001, respectively). In contrast, hemodynamic variables that are traditionally followed, such as cardiac power index, PCWP, blood pressure, and cardiac index, were not independently associated with 30-day mortality. For any value of SVI and SWI, outcome was better with ERV than with IMS.
Conclusions: SVI and SWI are the most powerful predictors of 30-day mortality in CS patients. Hemodynamic parameters following ERV and IMS are similar for survivors of the early shock period; however, outcomes are superior with ERV. Thus, early hemodynamic stability after IMS should not delay revascularization for patients presenting with CS complicating myocardial infarction.