Abstract 1845: Outcome following Coronary Artery Bypass Grafting and Percutaneous Coronary Intervention for Acute Myocardial Infarction Complicated by Cardiogenic Shock and Left Main Coronary Artery Stenosis: A Report from the SHOCK Trial and Registry
Background: The SHOCK Trial demonstrated that early revascularization (ERV) provided a survival advantage compared with initial medical stabilization in patients with acute myocardial infarction (MI). The ideal revascularization strategy for patients with cardiogenic shock in the setting of left main coronary artery (LMCA) disease is unknown.
Methods: We compared 30-day survival rates associated with coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) in this clinical setting. A multiple Cox regression model with left truncation was used to identify risk factors for 30-day mortality and attempt to correct for the bias that would be attributable to the differential time to revascularization.
Results: The SHOCK Trial (n=144) and Registry (=33) included 177 patients with significant (>50%) LMCA disease who underwent revascularization (CABG or PCI). Although the trial protocol recommended CABG for patients with LMCA involvement, the revascularization strategy (92 CABG and 85 PCI) was individualized for each patient by site investigators. The median time from MI to revascularization was 29.0 h (interquartile range [IQR], 10.0 to 90.8 h) in the CABG group and 7.5 h (IQR, 4.0 to 19.4 h) in the PCI group (p<0.05). Triple-vessel disease was more prevalent in the CABG group (87% vs. 73%, p<0.05). Overall 30-day survival with CABG in this setting was 59% which compared favorably with the 53% observed in the ERV arm of the SHOCK trial and was significantly superior to the 36% in the PCI group (p≤0.01). When the LMCA was the infarct-related artery, the 30-day survival rate was 50% in the CABG group (n=19) and 36% in the PCI group (n=25) (p=0.38). CABG [HR 0.36, 95% CI (0.19, 0.68), p=0.002) and age were independently associated with 30-day survival [HR 1.04, 95% CI (1.00–1.08); p=0.04] in this angiographic population.
Conclusions: CABG appears to be the optimal revascularization strategy in the setting of shock with LMCA involvement. Numerically superior outcomes with CABG in the subset of patients with LMCA as the infarct-related artery were also observed. The impact of current PCI strategies on this subgroup is undetermined.