Predictors of outcome after primary PTCA for acute myocardial infarction complicated by cardiogenic shock

Direct coronary angioplasty of the infarct related artery is well accepted as one of most important therapeutic options for cardiogenic shock (CS) complicating acute myocardial infarction (AMI). However, in-hospital still remains high. The aim of the following study was to analyse which clinical and procedural factors were associated with high or low in-hospital mortality when primary PTCA is applied systematically to all patients with CS within 12 h of symptom-onset. Patient characteristics: n = 78, age 60 ± 14 years, male 67%, primary venticular fibrillation, mechanical ventillation 59%, total branch block 24%.

Procedural data

Single-vessel-disease 41%, ejection fraction (acute biplane) 0.51 ± 0.16, infarct-related artery: LAD 38%, LCX 8%. RCA 54%: intra-aortic-balloon-pumping 17%, coronary stents 28%, successful angioplasty 87% (TIMI 3, residual stenosis <50%), in-hospital mortality (0-30 days) 49%. The most important predictors for a high in-hospital mortality rate were: acute ejection fraction <40% (P = 0.0035), unsuccessful PTCA (P < 0.05) and patient age >75 years (P < 0.05). A high in-hospital mortality rate was also seen in patients requiring mechanical ventillation. Mortality did not depend on the infarct location (inferior versus anterior), patient sex, ventricullar fibrillation or total branch block prior to intervention, single- or multi-vessel-disease. Furthermore mortality was independent of the time between onset of symptoms and PTCA and was also not affected by the employment of coronary stents or intra-aortic balloon conterpulsation.

Conclusion

Systematic primary-PTCA results in a lower in-hospital mortality rate when compared to conservative therapy of AMI with CS. However, mortality remains extremely high if angioplasty is unsuccesful. But even if myocardial perfusion is able to be re-established, patients initially requiring mechanical ventillation or with a low acute ejection-fraction as well as the very elderly >75 years of age maintain a poor prognosis.