One-year data from the CULPRIT-SHOCK trial indicate that there is no significant difference in all-cause mortality between cardiogenic shock patients undergoing immediate multivessel percutaneous coronary intervention (PCI) and those undergoing culprit-only PCI. These findings suggest that multivessel PCI is only associated with increased all-cause mortality in the first 30 days after the procedure.
The 30-day outcomes of CULPRIT-SHOCK, which were presented at the 2017 TCT meeting and published in the New England Journal of Medicine, showed the rate of the primary endpoint—a composite of all-cause death or renal replacement therapy—was significantly decreased with culprit-lesion PCI: 45.9% vs. 55.4% for the immediate multivessel PCI (p=0.01); a result thought to be driven by an absolute 8% reduction in all-cause death with culprit-lesion only PCI. Multivessel PCI was also associated with a trend towards more renal replacement therapy. This finding led the European Society of Cardiology and the European Association for Cardio-Thoracic Surgery (ESC/EACTS) to revise their recommendations for the use of multivessel disease in cardiogenic shock patients, downgrading multivessel PCI from “should be considered” to “not recommended”.
Writing in the New England Journal of Medicine, Holger Thiele (Department of Internal Medicine-Cardiology, Heart Center Leipzig, University of Leipzig, Leipzig, Germany) and colleagues report that the aim of the one-year analysis of CULPRIT-SHOCK trial was to further explore the safety and efficacy of multivessel PCI in the setting of caridogenic shock. Therefore, in the present analysis, they reviewed the one-year results of the pre-specified secondary endpoints (all-cause death, renal replacement therapy, recurrent myocardial infarction, repeat revascularisation, and rehospitalisation for heart failure).
In CULPRIT SHOCK, 706 patients with acute myocardial infarction, multivessel disease and cardiogenic shock were randomised to culprit-lesion only PCI (351) or immediate multivessel PCI (355). A one-year mortality rate of 50% for patients in the culprit-lesion only group and 56.9% in the immediate multivessel group (relative risk [RR] 0.88) was observed. However, culprit-lesion only PCI was associated with recurrent infarction rate of 1.7%, vs. 2.1% for multivessel PCI (RR 0.85); repeat revascularisations were also more frequent in patients with culprit-lesion only PCI than in those with immediate multivessel PCI (32.3% and 9.4%, respectively; RR 3.44), as were heart failure rehospitalisations (5.2% versus 1.2%, RR 4.46).
Thiele et al note that the study had several limitations, including the fact that the one-year endpoints are exploratory because the trial was powered for a 30-day analysis of the primary composite endpoint. Additionally, the trial was not blinded—allowing for the possibility of residual bias—and investigators were unable to use echocardiography to assess cardiac failure, which would have allowed the exploration of underlying causes for the higher 30-day mortality rate with multivessel PCI and for the higher rate of heart failure rehospitalisations witnessed with culprit-lesion only PCI.
Overall, the incidence of heart failure was low in both groups, with a small absolute difference, and the researchers suggested that it could be “a consequence of competing risks”. They explain: “Patients with cardiogenic shock are at an extreme risk for death, and if they die early they therefore do not survive long enough for heart failure to develop in the longer-term.” They further speculate that the higher rate of complete revascularisation in the immediate multivessel PCI group may have led to improved ventricular function, resulting in a lower incidence of heart failure among these patients. They add: “Because culprit-lesion only PCI has shown a benefit over multivessel PCI with respect to short-term survival, the risk of heart failure within the first year may be higher with culprit-lesion only PCI than with multivessel PCI.”
Thiele et al indicate that the higher incidence of repeat revascularisations in the culprit-lesion only PCI group could be related to the extent of coronary artery disease, the presence of impaired left ventricular function, and the severity of illness in patients with cardiogenic shock, as well as to the trial design, and conclude: “It is unclear whether an even higher rate of revascularisation of non-culprit lesions could have prevented rehospitalisations for heart failure.”
Coinciding with the publication in the New England Journal of Medicine, CULPRIT-SHOCK (one-year) were presented at the 2018 European Society of Cardiology (ESC) Congress (25–29 August, Munich, Germany).