POST-PCI Trial: Surveillance stress testing at 12 months offers no added benefit in high-risk PCI patients, regardless of ACS status

The prespecified analysis of the POST-PCI randomized clinical trial including 1706 patients revealed no incremental benefit from surveillance stress testing at 12 months compared with standard care alone in high-risk patients who had undergone PCI presenting with or without ACS.

"ACS patients had higher rates of major cardiovascular events (MACE) than those without ACS in the first year after PCI," the researchers reported in JAMA Cardiology. "A follow-up strategy of functional testing at 12 months failed to improve clinical outcomes during long-term follow-up compared with standard care, irrespective of initial ACS status."

Patients undergoing PCI after ACS represent a common and high-risk cohort within atherosclerosis management. Despite advancements in PCI devices and antithrombotic therapies, concerns persist regarding residual ischemic risk and recurrent cardiovascular events post-PCI. The optimal surveillance strategy for these patients remains contentious, with advocates proposing active surveillance to mitigate future ischemic events. Routine stress testing is frequently employed in clinical practice post-PCI, yet its prognostic significance in high-risk ACS patients remains uncertain.

Given the heightened risk of adverse cardiovascular events and mortality in ACS compared to stable coronary artery disease, the utility of routine stress testing warrants evaluation in this subgroup. Drawing upon data from the POST-PCI trial, which compared routine stress testing with standard care in high-risk PCI patients, Jinho Lee, University of Ulsan College of Medicine, Seoul, South Korea, and colleagues aimed to assess clinical outcomes based on randomized follow-up strategies at 12 months. This analysis specifically examines the impact of routine functional testing in patients initially presenting with ACS versus those without ACS.

The POST-PCI trial was a randomized clinical trial that compared routine functional testing follow-up strategies vs standard care alone 12 months after high-risk PCI. Patients were categorized as presenting with or without ACS. Patient enrollment was from 2017 through 2019, and patients were randomized from 11 sites in South Korea; data analysis was performed in 2022.

Patients categorized as presenting with or without ACS were randomized to either a routine functional testing or standard care alone follow-up strategy 12 months following high-risk PCI.

The primary endpoint assessed was a combination of mortality from any cause, myocardial infarction, or hospitalization due to unstable angina within two years from randomization. Kaplan-Meier curves were used to determine event rates over the study period, and Cox proportional hazard models were employed to calculate hazard ratios (HRs), with interactions also evaluated.

The study led to the following findings:

• Of 1706 included patients, 350 patients, 20.5% were female, and the mean patient age was 64.7 years. In total, 526 patients presented with ACS.
• Compared with those without ACS, patients with ACS had a 55% greater risk of the primary outcome (HR, 1.55) due to higher event rates in the first year.
• The 2-year incidences of the primary outcome were similar between strategies of routine functional testing or standard care alone in patients with ACS (functional testing: 6.6%; standard care: 8.5%; HR, 0.76) and patients without ACS (functional testing: 5.1%; standard care: 4.9%; HR, 1.04).
• Although a landmark analysis suggested that invasive angiography and repeat revascularization rates were higher after one year in the routine functional testing group, the formal interactions between ACS status and either invasive angiography or repeat revascularization were non-significant.

Among high-risk patients with acute coronary syndrome who underwent PCI, implementing routine surveillance functional testing 12 months post-PCI did not reduce the incidence of the primary composite outcome—including all-cause mortality, myocardial infarction (MI), or hospitalization for unstable angina—compared to those receiving standard care alone over two years.

"These findings were consistent irrespective of ACS status, though the study had insufficient statistical power to allow for firm conclusions," the researchers concluded.

Reference:

Lee J, Kang D, Kim H, et al. Routine Stress Testing After PCI in Patients With and Without Acute Coronary Syndrome: A Secondary Analysis of the POST-PCI Randomized Clinical Trial. JAMA Cardiol. Published online June 26, 2024. doi:10.1001/jamacardio.2024.1556