The PRAGUE 13 (Multivessel coronary disease diagnosed at the time of PPCI for STEMI: complete revascularization versus conservative strategy) trial indicates that treating culprit and non-culprit stenoses, through staged percutaneous coronary intervention (PCI), is not associated with significantly better outcomes than only treating the culprit vessel in patients with ST-segment elevation myocardial infarction (STEMI) and multivessel disease. These results are different from those of previous studies that have indicated that complete revascularisation does confer a benefit.
Speaking at EuroPCR (19–22 May, Paris, France), Ota Hlinomaz (ICRC, St Anne University Hospital, Brno, Czech Republic) reported that the aim of the study was to “find the optimal management of STEMI patients who have at least one significant stenosis of a non-culprit coronary artery.” Patients with acute STEMI were included in the study if they had undergone successful PCI and had at least one non-culprit artery with a stenosis of ≥70% (diameter ≥2.5mm). They were excluded if they had presented with symptomatic angina (>grade 2 Canadian Cardiovascular Society) one month (or less) prior to the STEMI. Hlinomaz noted that “importantly” all of the patients in the study could be categorised as being at low risk for a future cardiovascular event—only 35% presented with the left anterior descending artery as the infarct artery and only 6.1% had a ≥95% stenosis in the non-culprit artery, with most patients having an a stenosis of 80±10.1% in the non-culprit artery.
Of the 214 patients enrolled in the study, 106 were randomised to receive staged PCI (between the third and the 40th day after primary PCI) and 108 were randomised to receive conservative therapy (ie. optimal medical therapy) after PCI.
At the median follow-up point of 38 months, there were no significant differences in the rate of the composite primary endpoint (all-cause mortality, non-fatal myocardial infarction, and stroke) between groups: 16% for staged PCI vs. 13.9% for conservative therapy (p=0.407). Furthermore, there were no significant differences between groups in any of the individual components of the composite endpoint or in any of the secondary endpoints. “No non-infarct lesions progressed to myocardial infarction during follow-up, and progression of studied non-infarct lesions was very rare,” Hlinomaz noted.
He attributed this finding to the low-risk nature of the patients in the study, explaining: “If you include patients with non-culprit stenoses of ≥95% in this type of study, then of course the rate of the primary endpoint will be higher in the conservative arm [than in the intervention arm]. But if you include low-risk patients with stenoses of 80%, like we did, then you will have the results that we had. Therefore, the inclusion of high-risk patients is very important in terms of determining outcomes with staged PCI.”
Comparing the results of PRAGUE 13 to PRAMI (Randomised trial of preventive angioplasty in myocardial infarction) and CVLPRIT (Complete culprit-lesion only primary PCI trial), both of which indicated that complete revascularisation was beneficial in patients with multivessel disease, Hlinomaz said: “In PRAMI and CVLPRIT, 100% and 60% of non-culprit lesions, respectively, were treated during the primary PCI procedure. You cannot diagnose periprocedural myocardial infarction during a one-stage procedure because you cannot determine the increase in cardiac biomarkers [ie. which could affect the results].”
He concluded: “This trial found no difference—not even a trend favouring intervention—between staged multivessel PCI over culprit-only PCI in STEMI. Large trials are needed to clarify the revascularisation strategy in STEMI patients with multivessel disease.”