Routine Stress Testing After PCI in Patients With and Without Acute Coronary Syndrome: A Secondary Analysis of the POST-PCI Randomized Clinical Trial

Abstract

Importance: The appropriate follow-up surveillance strategy for patients with acute coronary syndrome (ACS) who have undergone percutaneous coronary intervention (PCI) remains unknown.

Objective: To assess clinical outcomes in patients with and without ACS who have undergone high-risk PCI according to a follow-up strategy of routine stress testing at 12 months after PCI vs standard care alone.

Design, setting, and participants: The POST-PCI (Pragmatic Trial Comparing Symptom-Oriented vs Routine Stress Testing in High-Risk Patients Undergoing Percutaneous Coronary Intervention) trial was a randomized clinical trial that compared follow-up strategies of routine functional testing vs standard care alone 12 months after high-risk PCI. Patients were categorized as presenting with or without ACS. Patients were enrolled in the trial from November 2017 through September 2019, and patients were randomized from 11 sites in South Korea; data analysis was performed in 2022.

Intervention: 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 after high-risk PCI.

Main outcomes and measures: The primary outcome was a composite of death from any cause, myocardial infarction, or hospitalization for unstable angina at 2 years following randomization. Kaplan-Meier event rates through 2 years and Cox model hazard ratios (HRs) were generated, and interactions were tested.

Results: Of 1706 included patients, 350 patients (20.5%) were female, and the mean (SD) patient age was 64.7 (10.3) years. In total, 526 patients (30.8%) presented with ACS. Compared with those without ACS, patients with ACS had a 55% greater risk of the primary outcome (HR, 1.55; 95% CI, 1.03-2.33; P = .03) 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: 16 of 251 [6.6%]; standard care: 23 of 275 [8.5%]; HR, 0.76; 95% CI, 0.40-1.44; P = .39) and in patients without ACS (functional testing: 30 of 598 [5.1%]; standard care: 28 of 582 [4.9%]; HR, 1.04; 95% CI, 0.62-1.74; P = .88) (P for interaction for ACS = .45). Although a landmark analysis suggested that the rates of invasive angiography and repeat revascularization were higher after 1 year in the routine functional testing group, the formal interactions between ACS status and either invasive angiography or repeat revascularization were not significant.

Conclusion and relevance: Despite being at higher risk for adverse clinical events in the first year after PCI than patients without ACS, patients with ACS who had undergone high-risk PCI did not derive incremental benefit from routine surveillance stress testing at 12 months compared with standard care alone during follow-up.

Trial registration: ClinicalTrials.gov Identifier: NCT03217877.

Figure 1.. CONSORT Flow Diagram

ACS indicates acute coronary syndrome.

Figure 2.. Landmark Analysis at Time of Intervention for the Primary Composite End Point and its Components in Patients With Acute Coronary Syndrome

Kaplan-Meier curves of landmark analysis of the cumulative incidence of the primary composite outcome of death from any cause, myocardial infarction, or hospitalization for unstable angina (A) in patients with acute coronary syndrome, and the cumulative incidence of the components of the primary composite: death from any cause (B), myocardial infarction (C), and hospitalization for unstable angina (D). The vertical dotted line indicates the intervention. The P values were determined by log-rank tests. HR indicates hazard ratio.

Figure 3.. Landmark Analysis at Time of Intervention for the Primary Composite End Point and its Components in Patients Without Acute Coronary Syndrome

Kaplan-Meier curves of landmark analysis of the cumulative incidence of the primary composite outcome of death from any cause, myocardial infarction, or hospitalization for unstable angina (A) in patients without acute coronary syndrome, and the cumulative incidence of the components of the primary composite: death from any cause (B), myocardial infarction (C), and hospitalization for unstable angina (D). The vertical dotted line indicates the intervention. The P values were determined by log-rank tests. HR indicates hazard ratio.