Evaluation of routine functional testing after percutaneous coronary intervention

Patient Management Following Percutaneous Coronary Intervention

Percutaneous coronary intervention (PCI) is a mainstay procedure for the treatment of coronary artery disease. PCI techniques have evolved considerably since the advent of PCI in 1978, and with this evolution in techniques has come changes in the best practices for patient management following PCI. The objective of this review is to provide a comprehensive overview of key considerations in patient management following PCI. The long-term management of patients post-PCI should follow 3 main principles: 1) lifestyle modification and reduction of risk factors; 2) implementation of secondary prevention therapies; and 3) timely detection of restenosis. Best practices in achieving these principles include promotion of smoking cessation, regular physical activity, and a healthy diet, as well as blood pressure, diabetes mellitus, lipid, and weight management; prescription of secondary prevention therapies balancing ischemic and bleeding risk; and avoidance of routine surveillance for restenosis.

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

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.

Routine Functional Testing or Standard Care in High-Risk Patients after Percutaneous Coronary Intervention

PURPOSE OF REVIEW

This review aimed to collate the available evidence on outcomes following routine functional stress testing vs standard of care (i.e. symptom-guided stress testing) in high-risk patients following percutaneous coronary intervention (PCI).

RECENT FINDINGS

The most recent pragmatic POST-PCI trial provided randomized evidence showing that routine functional stress testing post-PCI did not lead to a reduction in 2-year ischemic cardiovascular events or all-cause mortality, as compared to a symptom-guided standard-of-care approach. This was also true for sub-analyses including multivessel or left main disease, diabetics, as well as following imaging or physiology guided PCI. In the absence of a change in their clinical or functional status suggestive of stent failure, post-PCI routine periodic stress testing in stable patients on guideline-directed medical therapy is currently not recommended by American clinical practice guidelines. While evidence on the cost-effectiveness of routine stress testing strategy is scarce, physician, payer, and policy-level interventions to reduce inappropriate use of routine functional testing need to be addressed.

Routine Functional Testing or Standard Care in High-Risk Patients after PCI

BACKGROUND

There are limited data from randomized trials to guide a specific follow-up surveillance approach after myocardial revascularization. Whether a follow-up strategy that includes routine functional testing improves clinical outcomes among high-risk patients who have undergone percutaneous coronary intervention (PCI) is uncertain.

METHODS

We randomly assigned 1706 patients with high-risk anatomical or clinical characteristics who had undergone PCI to a follow-up strategy of routine functional testing (nuclear stress testing, exercise electrocardiography, or stress echocardiography) at 1 year after PCI or to standard care alone. The primary outcome was a composite of death from any cause, myocardial infarction, or hospitalization for unstable angina at 2 years. Key secondary outcomes included invasive coronary angiography and repeat revascularization.

RESULTS

The mean age of the patients was 64.7 years, 21.0% had left main disease, 43.5% had bifurcation disease, 69.8% had multivessel disease, 70.1% had diffuse long lesions, 38.7% had diabetes, and 96.4% had been treated with drug-eluting stents. At 2 years, a primary-outcome event had occurred in 46 of 849 patients (Kaplan-Meier estimate, 5.5%) in the functional-testing group and in 51 of 857 (Kaplan-Meier estimate, 6.0%) in the standard-care group (hazard ratio, 0.90; 95% confidence interval [CI], 0.61 to 1.35; P = 0.62). There were no between-group differences with respect to the components of the primary outcome. At 2 years, 12.3% of the patients in the functional-testing group and 9.3% in the standard-care group had undergone invasive coronary angiography (difference, 2.99 percentage points; 95% CI, -0.01 to 5.99), and 8.1% and 5.8% of patients, respectively, had undergone repeat revascularization (difference, 2.23 percentage points; 95% CI, -0.22 to 4.68).

CONCLUSIONS

Among high-risk patients who had undergone PCI, a follow-up strategy of routine functional testing, as compared with standard care alone, did not improve clinical outcomes at 2 years. (Funded by the CardioVascular Research Foundation and Daewoong Pharmaceutical; POST-PCI ClinicalTrials.gov number, NCT03217877.).

Pragmatic trial comparing routine versus no routine functional testing in high-risk patients who underwent percutaneous coronary intervention: Rationale and design of POST-PCI trial

BACKGROUND

Although the need to detect restenosis has diminished in the contemporary practice of percutaneous coronary intervention (PCI) with drug-eluting stents (DES), the surveillance of ischemia owing to restenosis or disease progression deserves attention in high-risk PCI settings. It is unknown whether follow-up strategy of routine noninvasive functional testing potentially reduces the risk of major cardiovascular events in high-risk PCI patients.

METHODS

The POST-PCI study is an investigator-initiated, multicenter, prospective randomized trial comparing the effectiveness of two follow-up strategies in patients with high-risk anatomic or clinical characteristics who underwent PCI. Study participants were randomly assigned to either (1) the routine noninvasive stress testing (exercise electrocardiography, nuclear stress imaging, or stress echocardiography) at 12 months post-PCI or (2) the standard-care without routine testing. In the routine stress testing group, depending on the testing results, all clinical decisions regarding subsequent diagnostic or therapeutic procedures were at the treating physician's discretion. The primary endpoint was a composite outcome of death from any causes, myocardial infarction, or hospitalization for unstable angina at 2 years post-PCI.

RESULTS

More than 1700 high-risk PCI patients have been randomized over 2.0 years at 11 major cardiac centers in Korea.

CONCLUSION

This pragmatic POST-PCI trial will provide valuable clinical evidence on the effectiveness of follow-up strategy of routine noninvasive stress testing in high-risk PCI patients.

Recurrent angina after coronary angioplasty: mechanisms, diagnostic and therapeutic options

Recurrent angina in patients who underwent percutaneous coronary intervention is defined as recurrence of chest pain or chest discomfort. Careful assessment is recommended to differentiate between non-cardiac and cardiac causes. In the case of the latter, recurrent angina occurrence can be related to structural ('stretch pain', in-stent restenosis, in-stent thrombosis, incomplete revascularization, progression of coronary atherosclerosis) or functional (coronary micro-vascular dysfunction, epicardial coronary spasm) causes. Even though a complete diagnostic algorithm has not been validated, ECG exercise testing, stress imaging and invasive assessment of coronary blood flow and coronary vaso-motion (i.e. coronary flow reserve, provocation testing for coronary spasm) may be required. When repeated coronary revascularization is not indicated, therapeutic approaches should aim at targeting the underlying mechanism for the patient's symptoms using a variety of drugs currently available such as beta-blockers, calcium-channel blockers, ivabradine or ranolazine.

Silent ischemia: clinical relevance

Myocardial ischemia can occur without overt symptoms. In fact, asymptomatic (or silent) ST-segment depression during ambulatory electrocardiogram monitoring occurs more often than symptomatic ST-segment depression in patients with coronary artery disease. Initial studies documented that silent ischemia provided independent prediction of adverse outcomes in patients with known and unknown coronary artery disease. The ACIP (Asymptomatic Cardiac Ischemia Pilot Study) enrolled patients in the 1990s and found that revascularization was better than medical therapy in reducing silent ischemic episodes and possibly cardiovascular (CV) events. However, the more recent COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation) trial found similar CV event rates between patients treated with optimal medical therapy alone and those treated with optimal medical therapy plus percutaneous revascularization. Therefore, in the current era, medical therapy appears to be as effective as revascularization in suppressing symptomatic ischemia and preventing CV events. COURAGE was not designed to evaluate changes in the frequency of silent ischemia. Therefore, silent ischemia may persist despite current-era treatment and might still identify patients with increased risk of CV events. Also, silent ischemia is likely to occur frequently in heart transplant patients with denervated hearts and coronary allograft vasculopathy, and future study aimed at improving the management of silent ischemia in this population is warranted. Additionally, future research is warranted to study the effect of newer medical therapies such as ranolazine or selected use of revascularization (for example, guided by fractional flow reserve) in those patients with persistent silent ischemia despite optimal current-era medical therapy.