Commentary
Patients presenting with STEMI often have multivessel disease.1 Although it is known that mortality can be reduced by early revascularization of the culprit vessel,2 whether the nonculprit vessel should be revascularized at the time of presentation with STEMI remains controversial.
Recently, multiple studies have reported the benefit of nonculprit vessel revascularization in patients presenting with hemodynamically stable STEMI. Four trials (PRAMI, CvPRIT, DANAMI-PRIMULTI, and COMPARE ACUTE) investigated this clinical question with different designs, and all reported benefit of nonculprit vessel revascularization compared to a culprit-only strategy.3-6 However, the differences in the composite endpoints were mainly driven by the softer endpoints used in these trials, such as refractory angina and ischemia-driven revascularization, and none of these previous trials had adequate power to evaluate differences in hard outcomes, such as death or MI.
In this context, Mehta et al investigated whether achieving complete revascularization by performing PCI on nonculprit vessels would improve the composite of cardiovascular death or MI compared to the culprit-only strategy by conducting a well-designed randomized controlled study. At median follow-up of 3 years, patients who underwent nonculprit vessel PCI had a lower incidence of death or MI compared to those who received the culprit-only strategy (7.8% versus 10.5%). The second co-primary endpoint (composite of death, MI, or ischemia-driven revascularization) also occurred significantly less frequently in the nonculprit PCI group than in the culprit-only PCI group (8.9% versus 16.7%).
The current study has a number of strengths. First, this was a multicenter, international study, and a large number of patients were enrolled (> 4000), achieving adequate power to evaluate for the composite of death and MI. Second, the treatments the patients received reflect contemporary medical therapy and interventional practice: the third-generation thienopyridine ticagrelor, high-dose statins, and ACE inhibitors were prescribed at high rates, and radial access (> 80%) and current-generation drug-eluting stents were used at high rates as well. Third, all angiograms were reviewed by the core lab to evaluate for completeness of revascularization. Fourth, the trial mandated use of fractional flow reserve to assess lesion stenosis 50% to 69% before considering revascularization, ensuring that only ischemic or very-high-grade lesions were revascularized. Fifth, the crossover rate in each group was low compared to the previous studies (4.7% into the complete revascularization group, 3.9% into the lesion-only group). Finally, this study evaluated the timing of the nonculprit PCI. Randomization to each group was stratified according to the intended timing of the nonculprit PCI during the index hospitalization or after hospital discharge (within 45 days). They found that benefit was consistent regardless of when the nonculprit PCI was performed.
Although the COMPLETE study’s design has a number of strengths, it is important to note that patients enrolled in this trial represent a lower-risk STEMI population. Patients with complex anatomy likely were not included, as evidenced by a lower SYNTAX score (mean, 16). Furthermore, no patients who presented with STEMI complicated by cardiogenic shock were enrolled. In the recent CULPRIT SHOCK trial, which focused on patients who had multivessel disease, acute MI, and cardiogenic shock, patients who underwent the culprit-only strategy had a lower rate of death or renal replacement therapy, as compared to patients who underwent immediate complete revascularization.7 Therefore, whether the findings from the COMPLETE study can be extended to a sicker population requires further study.