In patients admitted for ST-segment sus-elevation myocardial infarction (STEMI), revascularization is the corner stone of the management, completing the medical treatments [1,2]. Although it is widely accepted and strongly recommended that the culprit lesion has to be treated during the Primary Percutaneous Coronary Intervention (PPCI), the better option regarding the other lesions in case of multivessel disease remains controversial. On the one hand, treating only the culprit lesion allows a shorter procedure with less renal impairment and lower risk of acute stent thrombosis. On the other hand, treating all the stenoses allow to shorten the hospitalization, stabilize the unstable plaques (See Table 1 for a detailed description of the advantages/disadvantages imbalance of the two sides of the medal). Importantly, this dilemma is not at all rare but should represent 30% to half of the patients admitted for STEMI [1,2].

Table 1: Comparison of the two different options in case of multivessel disease revealed by a STEMI

A recent systemic review and metanalysis on this topic has just been published as well as an original work published in the leading medical journal [3,4]. In this important metanalysis, 26 studies with a total of 38,438 patients admitted for STEMI have been finally included [3]. The vast majority of them are not randomized (23 on 26). (See Table 2 for schematic description of the main features of the four prospective randomized trials available on this topic). The first three randomized trials have included only 339 patients. Among these three randomized trials, the multi-vessels PCI has been reported to be better than the culprit-only PCI as regards in hospital mortality (OR=0.24 (0.06-0.91), but only two small studies) and not in long-term mortality. Interestingly, among the non-randomized trials, it seems that the ideal timing of the revascularization is of great importance. As regards in-hospital mortality, immediate full revascularization is associated with poor outcomes (OR=1.35 (1.19-1.54)) whereas staged revascularization during the index hospitalization is associated with better outcomes (OR=0.35 (0.21-0.59). Similarly concerning the long term outcomes, immediate full revascularization is not statistically different from the culprit-only revascularization, but staged in hospital or later full revascularization is associated with better outcomes. Briefly, this work corroborates first that full revascularization, but perhaps not immediately during the index PCI, should be better that the culprit-only revascularization. Secondly, this analysis underlines that prospective randomized trials are mandatory.

Table 2: Main features of the four available prospective randomized trials on various strategies for PCI in patients admitted with STEMI and multivessel disease.

PPCI : Primary Percutaneous Coronary Intervention; STEMI : ST segment sus-elevation myocardial infarction; FFR : Flow Fraction Reserve; CTO : Chronic Total Occlusion; IRA : Infarction Related Artery; CABG : Coronary Artery Bypass Graft; AF : Atrial Fibrillation; MVD : MultiVessel Disease; LVEF : Left Ventricular Ejection Fraction; MACE : Major Adverse Cardiac Events

Recently, the important PRAMI trial was published [4]. In this prospective randomized trial, 465 patients with STEMI were treated by PCI (culprit lesion) and then randomly assigned either to preventive PCI or no preventive PCI. This trial has been largely discussed (at least 8 comments following the publication) on several points. The main concern is the choice to revascularize all stenoses>50% (and not 70% as usually recommended, except as regards the main left trunk). This full revascularization was performed at one time. In spite of all the concerns mentioned, this trial established for the first time a large prospective trial corroborating that full revascularization could be safe and better than the culprit-lesion only revascularization (the primary endpoint was a clinical composite endpoint; hazard ratio 0.35 (0.21-0.58).

Here, Dahud et al. (paper to quote by the editorial office) report a retrospective trial including 491 patients admitted for STEMI and presenting a multiple vessel disease. 69.5% of the patients were treated with immediate full revascularization during the index PCI, whereas 30.5% were treated only on the culprit lesion and treated later for the other lesions. Importantly, these two different procedures don't evaluate the culprit only versus the full revascularization, but compare the ideal timing for the full revascularization: either immediate or staged full revascularization. This trial is a large retrospective study, corroborating that immediate full revascularization could be interesting, with a significantly shorter hospitalization, less MACEs, although by contrast, transient renal dysfunction was more frequent. Many limitations are to rise. Beyond the retrospective design, the long duration for inclusions (procedures have evolved and stents or antiplatelet agents have changed for instance), one important concern is how the patients had been allocated to each group? The more severe patients are likely to have been allocated to the more simple procedure first. If true, the results are a very good surprise. As regards methods, the regression models could be more detailed (especially the impact of the different operators). On ethical point of view, informed consent and preferences of the patients are obviously difficult to obtain in the onetime full revascularization procedures. As no surgical back-up is available in this centre, heart team discussion is difficult.

In spite of all these limitations, the authors provide interesting real-life data, underlining that this question is not solved. On contrary, several trials currently on going are precisely addressing this issue as briefly presented in Table 3.

Table 3: Prospective randomized clinical trials currently registered dealing with STEMI and various PCI strategies for the management of patients with multiple vessel disease.

In conclusion, a systematic approach is difficult to recommend. Two schematic situations are to be considered. On the one hand, a young patient with two critical stenoses on the RCA and on the LDA. The culprit lesion is clearly the LDA. In case the revascularization of the LDA should be easy and quick, it seems then reasonable to treat the other lesion during the same procedure (immediate full revascularization). On the other hand, an old patient, with severe multiple stenoses, unknown (but likely impaired) renal function. In case the revascularization of the LDA should be long and difficult, it is obviously preferable to propose the angioplasty of the RCA later (staged procedure). The ideal delay, how to evaluate the stenosis, remain under debate. An individually tailored strategy should be the best option, but the best parameters to take into account are to be defined through prospective randomized trials currently on going (See Table 4 for some propositions presently taken into consideration routinely).

Table 4: How could we decide to continue or to stop the procedure?

Only trials comparing full revascularization to culprit-only revascularization are compared, not trials comparing for instance two different stents. Research with the keyword "multivessel disease", March 19th, 2014 on the clinicaltrials.gov site

NCT: National Clinical Trial, FFR: Fractional Flow Reserve; PPCI: Primary Percutaneous Coronary Intervention; IRA: Infarct-Related Artery

This is an editorial on the article "Infarct related artery only versus multivessel revascularization during primary PCI for STEMI” published in the Journal of Clinical & Experimental Cardiology.

The authors would like to acknowledge Drs Jean-Christophe MACIA, Richard GERVASONI and Thien-Tri CUNG (Montpellier University Hospital, France) for their suggestions and improvement of this manuscript.