Outcomes Research in Review

Non-Culprit Lesion PCI Strategies in Patients with Acute Myocardial Infarction and Cardiogenic Shock

Thiele H, Akin I, Sandri M, et al. PCI strategies in patients with acute myocardial infarction and cardiogenic shock. N Engl J Med 2017;377:2419–32


 

References

Study Overview

Objective. To determine if percutaneous coronary intervention (PCI) of non-culprit vessels should be performed in patients with acute myocardial infarction and cardiogenic shock.

Design. Multicenter randomized controlled trial.

Setting and participants. 706 patients who had multi­vessel disease, acute myocardial infarction, and cardiogenic shock were assigned to one of 2 revascularization strategies: PCI of the culprit lesion only with the option of staged revascularization of non-culprit lesions, or immediate multivessel PCI.

Main outcome measures. The primary endpoint was the composite of death or severe renal failure leading to renal replacement therapy within 30 days after randomization. Safety endpoints included bleeding and stroke.

Main results. The primary endpoint of death or renal replacement therapy occurred in 158 /344 patients (45.9%) in the culprit lesion–only PCI group and 189/341 patients (55.4%) in the multivessel PCI group (relative risk [RR] 0.83, 95% CI 0.72–0.96, P = 0.01). The rate of death from any cause was lower in the culprit lesion–only PCI group compared to multivessel PCI group (RR 0.84, 95% CI 0.72–0.98, P = 0.03). There was no difference in stroke and numerically lower risk of bleeding in culprit lesion–only PCI group (RR 0.75, 95% CI 0.55–1.03).

Conclusion. Among patients who had multivessel coronary artery disease and acute myocardial infarction with cardiogenic shock, the 30-day risk of death or severe renal failure leading to renal replacement therapy was lower in patients who initially underwent PCI of the culprit lesion only compared with patients who underwent immediate multivessel PCI.

Commentary

Patients presenting with cardiogenic shock at the time of acute myocardial infarction have the highest mortality—up to 50%. Since the original SHOCK trial in 1999, it is known that the mortality can be reduced by early revascularization of the culprit vessel [1]. However, whether the non-culprit vessel should be revascularized at the time of presentation with acute myocardial infarction is unknown.

Recently, there have been multiple trials suggesting the benefit of non-culprit vessel revascularization in patients with acute myocardial infarction who are hemodynamically stable at the time of their presentation. Three recent trials—PRAMI, CvPRIT and DANAMI-PRIMULTI—investigated this clinical question and found benefit of non-culprit vessel revascularization [2–4]. The results of these trials led to a focused update of the 2011 ACCF/AHA/SCAI guideline for percutaneous coronary intervention in 2015 [5]. Noninfarct-related artery PCI in hemodynamically stable patients presenting with acute myocardial infarction was upgraded to class IIb from class III [5]. Whether these findings can be extended to hemodynamically unstable (cardiogenic shock) patients is not mentioned in the guidelines.

In the current CULPRIT-SHOCK trial, Thiele et al investigated this clinical question by performing a well-designed clinical trial in patients with acute myocardial infarction and cardiogenic shock. They found that the composite endpoint of death and renal replacement therapy at 30 days occurred more frequently in the multivessel PCI group compared with the culprit lesion–only group (relative risk [RR] 0.83, 95% CI 0.71–0.96, P = 0.01). The composite endpoint was mainly driven by death (43.3% vs 51.6%, RR 0.84, 95% CI 0.72–0.98, P = 0.03), and the rate of renal replacement therapy was numerically higher in the mutivessel PCI group (11.6% vs 16.4%, P = 0.07). The study was conducted in the sickest population compared to prior trials as evidenced by high rate of mechanical ventilation (~80%), requirement of catecholamine support (~90%), and long ICU stay (median 5 days). The significance of non-culprit lesion was determined by angiogram (stenosis > 70%). The culprit vessel–only group had treatment of the culprit vessel only initially, but the staged intervention for non-culprit vessel was encouraged.

A unique point of this trial is that patients with chronic total occlusion (CTO) were included in the study and it was encouraged to attempt revascularization of CTO lesions, contrary to previous trials. Although CTO intervention improves angina and ejection fraction [6,7], whether CTO intervention has a mortality benefit needs further investigation. In the CULPRIT-SHOCK trial, 24% of patients had one or more CTO lesions. This most likely contributed to the increased contrast use in the multivessel PCI group (250 vs 190 mL, P < 0.01). CTO is considered a most challenging lesion to treat, and expertise and skill level vary among operators. In the hybrid CTO intervention model, it is recommended to stage the intervention as much as possible, as this type of intervention requires meticulous planning [8]. There is a possibility that attempting CTO intervention in this acute setting caused more harm than benefit. Furthermore, the investigators did not report the success rate of CTO intervention.

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