Culprit lesion location and outcome in patients with cardiogenic shock complicating myocardial infarction: a substudy of the IABP-SHOCK II-trial.

Background: In myocardial infarction without cardiogenic shock (CS), the affected coronary vessel has significant influence on the final infarct size and patient prognosis. CS data on this relation are scarce. The objective of this study was to determine the prognostic relevance of the culprit lesion location in patients with CS complicating acute myocardial infarction.

Methods: In the Intraaortic Balloon Pump in Cardiogenic Shock II (IABP-SHOCK II) trial patients with CS were randomized to therapy with intraaortic balloon pump or control. Additional CS patients not eligible for the randomized trial were included in a registry. We compared the location of the culprit lesions in these patients with regard to the affected coronary vessel [left main (LM), left anterior descending (LAD), left circumflex (LCX) and right coronary artery (RCA)] and location within the vessel (proximal, mid or distal) regarding short- and long-term outcome.

Results: Of 758 patients, the majority had the culprit lesion in the LAD (44 %) compared to RCA (27 %), LCX (19 %) or LM (10 %). Proximal lesions were more frequent than mid or distal culprit lesions (60 vs. 27 vs. 13 %, p < 0.001). No differences were observed for mortality with respect to either culprit vessel (log-rank p value = 0.54). In contrast, a higher mortality was observed for patients with distal culprit lesions after 1 year (log-rank p value = 0.04). This difference persisted after multivariable adjustment (hazard ratio for distal lesions 1.40; 95 % confidential interval 1.03-1.90; p = 0.03).

Conclusion: For patients with CS complicating myocardial infarction, the culprit vessel seems to be unrelated with mortality whereas distal culprit lesions may have a worse outcome.