Previous studies have shown complete revascularization is associated with better prognosis compared with culprit lesion only PCI in patients with STEMI. In the Preventive Angioplasty in Acute Myocardial Infarction (PRAMI) trial,1) preventive PCI in non-infarct-related coronary arteries with significant stenosis was associated with 65% reduction of cardiovascular death, myocardial infarction (MI) and refractory angina. In another study with second generation stents, complete revascularization strategy also showed better outcomes with reduction of 44% of cardiovascular death than culprit lesion only PCI in STEMI patients with multi vessel disease.2) However, there have been issued regarding interval of 2nd PCI of the remaining lesions to achieve complete revascularization after the treatment of culprit lesion.

In this current issue, Ahn et al.3) investigated the optimal timing of non-culprit lesions PCI by using Korea Acute Myocardial Infarction Registry-National Institute of Health (KAMIR-NIH) data. A total of 606 patients with STEMI and multi-vessel coronary artery disease underwent complete revascularization including non-culprit lesions with significant stenosis. Authors compared 1-year clinical outcomes between multi-vessel single-stage PCI (SS PCI) group (n=325) and multi-vessel multi-staged PCI (MS PCI) group (n=195). At 1 year, MS PCI group showed a lower rate of all-cause mortality (hazard ratio [HR], 0.42; 95% confidence interval [CI], 0.19–0.92; p=0.030) compared with SS PCI group.

Recent European Society of Cardiology (ESC) guidelines recommended that the treatment for non-culprit lesions PCI should be considered before the discharge (class IIa, A). However, the exact timing is still controversial and is needed to be investigated.4) Current study may provide the important information that the timing of the second stage PCI is median 6 days before discharge in MS PCI group. This finding is consistent with result of other study. Kim et al.5) presented optimal timing of PCI for non-culprit vessel in patients with STEMI and MVD was less than 7 days (2–6 days) after index PCI, but deferred staged PCI after 1 week of index PCI group was associated with the higher a composite of all-cause mortality, MI or repeat PCI (odds ratio [OR], 1.83; 95% confidence interval [CI], 1.06–3.18, p=0.031) as compared to group with simultaneous multi-vessel PCI group. It is also in line with the ESC guideline which recommend staged PCI before discharge in admission for primary PCI.

ESC guideline also suggested that non-infarct-related artery PCI during the index procedure should be considered in patients with cardiogenic shock (class IIa, C) based on a consensus opinion without randomized clinical trial. However, this study demonstrated all-cause mortality was high in the subgroup of cardiogenic shock (HR, 4.60; 95% CI, 1.536–13.774; p=0.006) in the SS PCI group. Furthermore, high risk patients such as age ≥65 years (HR, 4.00; 95% CI, 1.670–9.58, p=0.002), Killip class III/IV (HR, 7.32; 95% CI, 1.68–31.87; p=0.008), and creatinine clearance ≤60 mL/min (HR, 2.81; 95% CI, 1.10–7.18; p=0.031) showed higher all-cause mortality of the SS PCI group than those of MS PCI group. However, these findings should be interpreted with consideration of possible selection bias.

There was no clear evidence of clinical benefits between SS PCI and MS PCI as well as an optimal timing between the index procedure and staged PCI in MS PCI. However, this study implied clinical relevance for the timing of second stage PCI in patients with STEMI and MVD.