Fractional Flow Reserve and Instantaneous Wave-Free Ratio as Predictors of the Placebo-Controlled Response to Percutaneous Coronary Intervention in Stable Single-Vessel Coronary Artery Disease

Placebo Control and Blinding in Randomized Trials of Procedural Interventions: A Systematic Review and Meta-Regression

Importance

Unlike medications, procedural interventions are rarely trialed against placebo prior to becoming accepted in clinical practice. When placebo-controlled trials are eventually conducted, procedural interventions may be less effective than previously believed.

Objective

To investigate the importance of including a placebo arm in trials of surgical and interventional procedures by comparing effect sizes from trials of the same procedure that do and do not include a placebo arm.

Data Sources

Searches of MEDLINE and Embase identified all placebo-controlled trials for procedural interventions in any specialty of medicine and surgery from inception to March 31, 2019. A secondary search identified randomized clinical trials assessing the same intervention, condition, and end point but without a placebo arm for paired comparison.

Study Selection

Placebo-controlled trials of anatomically site-specific procedures requiring skin incision or endoscopic techniques were eligible for inclusion; these were then matched to trials without placebo control that fell within prespecified limits of heterogeneity.

Data Extraction and Synthesis

Random-effects meta-regression, with placebo and blinding as a fixed effect and intervention and end point grouping as random effects, was used to calculate the impact of placebo control for each end point. Data were analyzed from March 2019 to March 2020.

Main Outcomes and Measures

End points were examined in prespecified subgroups: patient-reported or health care professional-assessed outcomes, quality of life, pain, blood pressure, exercise-related outcomes, recurrent bleeding, and all-cause mortality.

Results

Ninety-seven end points were matched from 72 blinded, placebo-controlled trials (hereafter, blinded) and 55 unblinded trials without placebo control (hereafter, unblinded), including 111 500 individual patient end points. Unblinded trials had larger standardized effect sizes than blinded trials for exercise-related outcomes (standardized mean difference [SMD], 0.59; 95% CI, 0.29 to 0.89; P < .001) and quality-of-life (SMD, 0.32; 95% CI, 0.11 to 0.53; P = .003) and health care professional-assessed end points (SMD, 0.40; 95% CI, 0.18 to 0.61; P < .001). The placebo effect accounted for 88.1%, 55.2%, and 61.3% of the observed unblinded effect size for these end points, respectively. There was no significant difference between unblinded and blinded trials for patient-reported end points (SMD, 0.31; 95% CI, -0.02 to 0.64; P = .07), blood pressure (SMD, 0.26; 95% CI, -0.10 to 0.62; P = .15), all-cause mortality (odds ratio [OR], 0.23; 95% CI, -0.26 to 0.72; P = .36), pain (SMD, 0.03; 95% CI, -0.52 to 0.57; P = .91), or recurrent bleeding events (OR, -0.12; 95% CI, -1.11 to 0.88; P = .88).

Conclusions and Relevance

The magnitude of the placebo effect found in this systematic review and meta-regression was dependent on the end point. Placebo control in trials of procedural interventions had the greatest impact on exercise-related, quality-of-life, and health care professional-assessed end points. Randomized clinical trials of procedural interventions may consider placebo control accordingly.

Targeted Therapies for Microvascular Disease

Coronary microvascular dysfunction (CMD) is a common cause of ischemia but no obstructive coronary artery disease that results in an inability of the coronary microvasculature to meet myocardial oxygen demand. CMD is challenging to diagnose and manage due to a lack of mechanistic research and targeted therapy. Recent evidence suggests we can improved patient outcomes by stratifying antianginal therapies according to the diagnosis revealed by invasive assessment of the coronary microcirculation. This review article appraises the evidence for management of CMD, which includes treatment of cardiovascular risk, antianginal therapy and therapy for atherosclerosis.

ChaMP-CMD: A Phenotype-Blinded, Randomized Controlled, Cross-Over Trial

BACKGROUND

Angina with nonobstructive coronary arteries is a common condition for which no effective treatment has been established. We hypothesized that the measurement of coronary flow reserve (CFR) allows identification of patients with angina with nonobstructive coronary arteries who would benefit from anti-ischemic therapy.

METHODS

Patients with angina with nonobstructive coronary arteries underwent blinded invasive CFR measurement and were randomly assigned to receive 4 weeks of amlodipine or ranolazine. After a 1-week washout, they crossed over to the other drug for 4 weeks; final assessment was after the cessation of study medication for another 4 weeks. The primary outcome was change in treadmill exercise time, and the secondary outcome was change in Seattle Angina Questionnaire summary score in response to anti-ischemic therapy. Analysis was on a per protocol basis according to the following classification: coronary microvascular disease (CMD group) if CFR<2.5 and reference group if CFR≥2.5. The study protocol was registered before the first patient was enrolled (International Standard Randomised Controlled Trial Number: ISRCTN94728379).

RESULTS

Eighty-seven patients (61±8 years of age; 62% women) underwent random assignment (57 CMD group and 30 reference group). Baseline exercise time and Seattle Angina Questionnaire summary scores were similar between groups. The CMD group had a greater increment (delta) in exercise time than the reference group in response to both amlodipine (difference in delta, 82 s [95% CI, 37-126 s]; P<0.001) and ranolazine (difference in delta, 68 s [95% CI, 21-115 s]; P=0.005). The CMD group reported a greater increment (delta) in Seattle Angina Questionnaire summary score than the reference group in response to ranolazine (difference in delta, 7 points [95% CI, 0-15]; P=0.048), but not to amlodipine (difference in delta, 2 points [95% CI, -5 to 8]; P=0.549).

CONCLUSIONS

Among phenotypically similar patients with angina with nonobstructive coronary arteries, only those with an impaired CFR derive benefit from anti-ischemic therapy. These findings support measurement of CFR to diagnose and guide management of this otherwise heterogeneous patient group.

Targeted Therapies for Microvascular Disease

Coronary microvascular dysfunction (CMD) is a common cause of ischemia but no obstructive coronary artery disease that results in an inability of the coronary microvasculature to meet myocardial oxygen demand. CMD is challenging to diagnose and manage due to a lack of mechanistic research and targeted therapy. Recent evidence suggests we can improved patient outcomes by stratifying antianginal therapies according to the diagnosis revealed by invasive assessment of the coronary microcirculation. This review article appraises the evidence for management of CMD, which includes treatment of cardiovascular risk, antianginal therapy and therapy for atherosclerosis.

Changes in post-PCI physiology based on anatomical vessel location: a DEFINE PCI substudy

BACKGROUND

Anatomical vessel location affects post-percutaneous coronary intervention (PCI) physiology.

AIMS

We aimed to compare the post-PCI instantaneous wave-free ratio (iFR) in left anterior descending (LAD) versus non-LAD vessels and to identify the factors associated with a suboptimal post-PCI iFR.

METHODS

DEFINE PCI was a multicentre, prospective, observational study in which a blinded post-PCI iFR pullback was used to assess residual ischaemia following angiographically successful PCI.

RESULTS

Pre- and post-PCI iFR recordings of 311 LAD and 195 non-LAD vessels were compared. Though pre-PCI iFR in the LAD vessels (median 0.82 [0.63, 0.86]) were higher compared with those in non-LAD vessels (median 0.72 [0.49, 0.84]; p<0.0001), post-PCI iFR were lower in the LAD vessels (median 0.92 [0.88, 0.94] vs 0.98 [0.95, 1.00]; p<0.0001). The prevalence of a suboptimal post-PCI iFR of <0.95 was higher in the LAD vessels (77.8% vs 22.6%; p<0.0001). While the overall frequency of residual physiological diffuse disease (31.4% vs 38.6%; p=0.26) and residual focal disease in the non-stented segment (49.6% vs 50.0%; p=0.99) were similar in both groups, residual focal disease within the stented segment was more common in LAD versus non-LAD vessels (53.7% vs 27.3%; p=0.0009). Improvement in iFR from pre- to post-PCI was associated with angina relief regardless of vessel location.

CONCLUSIONS

After angiographically successful PCI, post-PCI iFR is lower in the LAD compared with non-LAD vessels, resulting in a higher prevalence of suboptimal post-PCI iFR in LAD vessels. This difference is, in part, due to a greater frequency of a residual focal pressure gradient within the stented segment which may be amenable to more aggressive PCI.

Coronary "Microvascular Dysfunction": Evolving Understanding of Pathophysiology, Clinical Implications, and Potential Therapeutics

Until recently, it has been generally held that stable angina pectoris (SAP) primarily reflects the presence of epicardial coronary artery stenoses due to atheromatous plaque(s), while acute myocardial infarction (AMI) results from thrombus formation on ruptured plaques. This concept is now challenged, especially by results of the ORBITA and ISCHEMIA trials, which showed that angioplasty/stenting does not substantially relieve SAP symptoms or prevent AMI or death in such patients. These disappointing outcomes serve to redirect attention towards anomalies of small coronary physiology. Recent studies suggest that coronary microvasculature is often both structurally and physiologically abnormal irrespective of the presence or absence of large coronary artery stenoses. Structural remodelling of the coronary microvasculature appears to be induced primarily by inflammation initiated by mast cell, platelet, and neutrophil activation, leading to erosion of the endothelial glycocalyx. This leads to the disruption of laminar flow and the facilitation of endothelial platelet interaction. Glycocalyx shedding has been implicated in the pathophysiology of coronary artery spasm, cardiovascular ageing, AMI, and viral vasculitis. Physiological dysfunction is closely linked to structural remodelling and occurs in most patients with myocardial ischemia, irrespective of the presence or absence of large-vessel stenoses. Dysfunction includes the impairment of platelet and vascular responsiveness to autocidal coronary vasodilators, such as nitric oxide, prostacyclin, and hydrogen sulphide, and predisposes both to coronary vasoconstriction and to a propensity for microthrombus formation. These findings emphasise the need for new directions in medical therapeutics for patients with SAP, as well as a wide range of other cardiovascular disorders.

Targeted Therapies for Microvascular Disease

Coronary microvascular dysfunction (CMD) is a common cause of ischemia but no obstructive coronary artery disease that results in an inability of the coronary microvasculature to meet myocardial oxygen demand. CMD is challenging to diagnose and manage due to a lack of mechanistic research and targeted therapy. Recent evidence suggests we can improved patient outcomes by stratifying antianginal therapies according to the diagnosis revealed by invasive assessment of the coronary microcirculation. This review article appraises the evidence for management of CMD, which includes treatment of cardiovascular risk, antianginal therapy and therapy for atherosclerosis.

Complete Revascularization vs Culprit Lesion-Only Percutaneous Coronary Intervention for Angina-Related Quality of Life in Patients With ST-Segment Elevation Myocardial Infarction: Results From the COMPLETE Randomized Clinical Trial

Importance

In patients with multivessel coronary artery disease (CAD) presenting with ST-segment elevation myocardial infarction (STEMI), complete revascularization reduces major cardiovascular events compared with culprit lesion-only percutaneous coronary intervention (PCI). Whether complete revascularization also improves angina-related health status is unknown.

Objective

To determine whether complete revascularization improves angina status in patients with STEMI and multivessel CAD.

Design, Setting, and Participants

This secondary analysis of a randomized, multinational, open label trial of patient-reported outcomes took place in 140 primary PCI centers in 31 countries. Patients presenting with STEMI and multivessel CAD were randomized between February 1, 2013, and March 6, 2017. Analysis took place between July 2021 and December 2021.

Interventions

Following PCI of the culprit lesion, patients with STEMI and multivessel CAD were randomized to receive either complete revascularization with additional PCI of angiographically significant nonculprit lesions or to no further revascularization.

Main Outcomes and Measures

Seattle Angina Questionnaire Angina Frequency (SAQ-AF) score (range, 0 [daily angina] to 100 [no angina]) and the proportion of angina-free individuals by study end.

Results

Of 4041 patients, 2016 were randomized to complete revascularization and 2025 to culprit lesion-only PCI. The mean (SD) age of patients was 62 (10.7) years, and 3225 (80%) were male. The mean (SD) SAQ-AF score increased from 87.1 (17.8) points at baseline to 97.1 (9.7) points at a median follow-up of 3 years in the complete revascularization group (score change, 9.9 [95% CI, 9.0-10.8]; P < .001) compared with an increase of 87.2 (18.4) to 96.3 (10.9) points (score change, 8.9 [95% CI, 8.0-9.8]; P < .001) in the culprit lesion-only group (between-group difference, 0.97 points [95% CI, 0.27-1.67]; P = .006). Overall, 1457 patients (87.5%) were free of angina (SAQ-AF score, 100) in the complete revascularization group compared with 1376 patients (84.3%) in the culprit lesion-only group (absolute difference, 3.2% [95% CI, 0.7%-5.7%]; P = .01). This benefit was observed mainly in patients with nonculprit lesion stenosis severity of 80% or more (absolute difference, 4.7%; interaction P = .02).

Conclusions and Relevance

In patients with STEMI and multivessel CAD, complete revascularization resulted in a slightly greater proportion of patients being angina-free compared with a culprit lesion-only strategy. This modest incremental improvement in health status is in addition to the established benefit of complete revascularization in reducing cardiovascular events.

Remote digital smart device follow-up in prospective clinical trials: early insights from ORBITA-2, ORBITA-COSMIC, and ORBITA-STAR

Smart devices are a fundamental media for acquisition, processing, storage, and transfer of digital health data. The global penetration and high frequency usage of smart devices such as smartphones and fitness monitors provide us an opportunity for incorporation into clinical trials to generate more clinically meaningful data. Reporting of angina can significantly vary between patients and also within patients at different timepoints. Furthermore, the nature of angina can lead to variation in ways patients adapt their activities of daily living and hence reporting of symptoms and quality of life. Current clinical trials investigating the effects of intervention on angina do not accurately incorporate these patient centred outcomes and considerations. Hence, methods to contemporaneously assess daily angina burden in a convenient, patient focused, and cost-effective manner are priorities for contemporary clinical trials to address. In this article, we provide our insights into the use of remote digital smart devices in clinical trials of stable coronary artery disease conducted by our research group. We discuss how our experiences from previous trials necessitated its incorporation and will provide us with important data that will inform clinical practice. We discuss the benefits and current challenges and limitations of smart device incorporation while providing our procedural workflow for how we incorporated smart devices into our clinical trials for others to consider. We hope that this approach will allow us to understand the perceptions and implications of angina on patient lives with greater granularity than previously explored.

Coronary physiology in the catheterisation laboratory: an A to Z practical guide

Coronary revascularisation, either percutaneous or surgical, aims to improve coronary flow and relieve myocardial ischaemia. The decision-making process in patients with coronary artery disease (CAD) remains largely based on invasive coronary angiography (ICA), even though until recently ICA could not assess the functional significance of coronary artery stenoses. Invasive wire-based approaches for physiological evaluations were developed to properly assess the ischaemic relevance of epicardial CAD. Fractional flow reserve (FFR) and later, instantaneous wave-free ratio (iFR), were shown to improve clinical outcomes in several patient subsets when used for coronary revascularisation guidance or deferral and for procedural optimisation of percutaneous coronary intervention (PCI) results. Despite accumulating evidence and positive guideline recommendations, the adoption of invasive physiology has remained quite low, mainly due to technical and economic issues as well as to operator-resistance to change. Coronary image-based computational physiology has been recently developed, with promising results in terms of accuracy and a reduction in computational time, costs, radiation exposure and risks for the patient. Lastly, the integration of intracoronary imaging and physiology allows for individualised PCI treatment, aiming at complete relief of ischaemia through optimised morpho-functional immediate procedural results. Instead of a conventional state-of-the-art review, this A to Z dictionary attempts to provide a practical guide for the application of coronary physiology in the catheterisation laboratory, exploring several methods, their pitfalls, and useful tips and tricks.

Immediate impact of coronary artery bypass graft surgery on regional myocardial perfusion: Results from the Collaborative Pilot Study to Determine the Correlation Between Intraoperative Observations Using Spy Near-Infrared Imaging and Cardiac Catheterization Laboratory Physiological Assessment of Lesion Severity

Objectives

Coronary artery bypass grafting (CABG) is performed using anatomic guidance. Data connecting the physiologic significance of the coronary vessel stenosis to the acute physiologic response to grafting are lacking. The Collaborative Pilot Study to Determine the Correlation Between Intraoperative Observations Using Spy Near-Infrared Imaging and Cardiac Catheterization Laboratory Physiological Assessment of Lesion Severity study is the first to compare preintervention coronary physiology with the acute regional myocardial perfusion change (RMP-QC) at CABG in a per-graft analysis.

Methods

Non-emergent patients undergoing diagnostic catheterization suitable for multivessel CABG were enrolled. Synergy between Percutaneous Coronary Intervention with Taxus score, fractional flow reserve (FFR), instantaneous wave free ratio (iFR), and quantitative coronary angiography was documented in 75 epicardial coronary arteries, with 62 angiographically intermediate and 13 severe stenoses. At CABG, near-infrared fluorescence analysis quantified the relative change (post- vs pregrafting, termed RMP-QC) in the grafted vessel's perfusion territory. Scatter plots were constructed for RMP-QC versus quantitative coronary angiography and RMP-QC versus FFR/iFR. Exact quadrant randomization test for randomness was used.

Results

There was no relationship between RMP-QC and quantitative coronary angiography percent diameter stenosis, whether all study vessels were included (P = .949) or vessels with core-lab quantitative coronary angiography only (P = .922). A significant nonrandom association between RMP-QC and FFR (P = .025), as well as between RMP-QC and iFR (P = .008), was documented. These associations remained when excluding vessels with assigned FFR and iFR values (P = .0092 and P = .0006 for FFR and iFR, respectively).

Conclusions

The Collaborative Pilot Study to Determine the Correlation Between Intraoperative Observations Using Spy Near-Infrared Imaging and Cardiac Catheterization Laboratory Physiological Assessment of Lesion Severity study demonstrates there is no association between angiographic coronary stenosis severity and the acute perfusion change after grafting; there is an association between functional stenosis severity and absolute increase in regional myocardial perfusion after CABG.

Cardiopulmonary exercise testing and efficacy of percutaneous coronary intervention: a substudy of the ORBITA trial

AIMS

Oxygen-pulse morphology and gas exchange analysis measured during cardiopulmonary exercise testing (CPET) has been associated with myocardial ischaemia. The aim of this analysis was to examine the relationship between CPET parameters, myocardial ischaemia and anginal symptoms in patients with chronic coronary syndrome and to determine the ability of these parameters to predict the placebo-controlled response to percutaneous coronary intervention (PCI).

METHODS AND RESULTS

Patients with severe single-vessel coronary artery disease (CAD) were randomized 1:1 to PCI or placebo in the ORBITA trial. Subjects underwent pre-randomization treadmill CPET, dobutamine stress echocardiography (DSE) and symptom assessment. These assessments were repeated at the end of a 6-week blinded follow-up period.A total of 195 patients with CPET data were randomized (102 PCI, 93 placebo). Patients in whom an oxygen-pulse plateau was observed during CPET had higher (more ischaemic) DSE score [+0.82 segments; 95% confidence interval (CI): 0.40 to 1.25, P = 0.0068] and lower fractional flow reserve (-0.07; 95% CI: -0.12 to -0.02, P = 0.011) compared with those without. At lower (more abnormal) oxygen-pulse slopes, there was a larger improvement of the placebo-controlled effect of PCI on DSE score [oxygen-pulse plateau presence (Pinteraction = 0.026) and oxygen-pulse gradient (Pinteraction = 0.023)] and Seattle angina physical-limitation score [oxygen-pulse plateau presence (Pinteraction = 0.037)]. Impaired peak VO2, VE/VCO2 slope, peak oxygen-pulse, and oxygen uptake efficacy slope was significantly associated with higher symptom burden but did not relate to severity of ischaemia or predict response to PCI.

CONCLUSION

Although selected CPET parameters relate to severity of angina symptoms and quality of life, only an oxygen-pulse plateau detects the severity of myocardial ischaemia and predicts the placebo-controlled efficacy of PCI in patients with single-vessel CAD.

Computed tomography-derived fractional flow reserve (FFRCT) has no additional clinical impact over the anatomical Coronary Artery Disease - Reporting and Data System (CAD-RADS) in real-world elective healthcare of coronary artery disease

AIM

To evaluate the impact of computed tomography-derived fractional flow reserve (FFR_CT) compared to the anatomical Coronary Artery Disease - Reporting and Data System (CAD-RADS) in the elective assessment of coronary artery disease in real-world cardiology practise.

MATERIALS AND METHODS

A retrospective review was undertaken of 1,239 coronary CT examinations from August 2018 to December 2019 with a minimum follow-up period of 1 year. Coronary disease was classified according to the CAD-RADS system. A non-occlusive ≥30% maximum diameter stenosis was considered eligible for FFR_CT. Lesion-specific FFR_CT and FFR were considered positive if ≤ 0.80. The patients were followed up using the hospital radiology information system and the electronic patient record. A positive outcome was defined by a subsequent invasive angiogram (ICA) showing disease requiring revascularisation or FFR ≤0.80 or a positive stress test or medical therapy for angina in CAD-RADS 4.

RESULTS

Of the 1,145 analysable studies (mean follow up 618 ± 153 days) the incidence of a positive result was 7% with a 5.4% elective revascularisation rate. Two hundred and forty-five patients (CAD-RADS 2-4) had FFR_CT. FFR_CT reduced the accuracy of the CAD-RADS grade from 91% to 78.4% (p<0.001). In CAD-RADS 2, the accuracy is reduced from 99% to 90.7% (p=0.005), and in CAD-RADS 3 from 93.9% to 67.7% (p<0.001). In CAD-RADS 4, FFR_CT increases accuracy from 69.4% to 75.5% (p=0.025), but 89.8% of FFR_CT are positive and specificity is low (26.7%).

CONCLUSION

In the present "real-world" practise, FFR_CT does not improve standard radiological assessment of coronary disease graded by the CAD-RADS alone.

Revascularization in stable coronary artery disease

Management of stable coronary artery disease (CAD) centers on medication to prevent myocardial infarction and death. Many anti-anginal medications also have benefit for reducing symptoms, and have been proven to be effective against placebo control. Before effective preventive medications were available, patients with stable CAD often underwent revascularization with coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI), on the plausible assumption that these procedures would prevent adverse events and reduce symptoms. However, recent randomized controlled trials have cast doubt on these assumptions.Considering results from the recent ISCHEMIA trial, we discuss the evidence base that underpins revascularization for stable CAD in contemporary practice. We also focus on patient groups at high risk of myocardial infarction and death, for whom revascularization is often recommended. We outline the areas of uncertainty, unanswered research questions, and key areas of potential miscommunication in doctor-patient consultations.

Comprehensive Quality-of-Life Outcomes With Invasive Versus Conservative Management of Chronic Coronary Disease in ISCHEMIA

BACKGROUND

ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) compared an initial invasive treatment strategy (INV) with an initial conservative strategy in 5179 participants with chronic coronary disease and moderate or severe ischemia. The ISCHEMIA research program included a comprehensive quality-of-life (QOL) substudy.

METHODS

In 1819 participants (907 INV, 912 conservative strategy), we collected a battery of disease-specific and generic QOL instruments by structured interviews at baseline; at 3, 12, 24, and 36 months postrandomization; and at study closeout. Assessments included angina-related QOL (19-item Seattle Angina Questionnaire), generic health status (EQ-5D), depressive symptoms (Patient Health Questionnaire-8), and, for North American patients, cardiac functional status (Duke Activity Status Index).

RESULTS

Median age was 67 years, 19.2% were female, and 15.9% were non-White. The estimated mean difference for the 19-item Seattle Angina Questionnaire Summary score favored INV (1.4 points [95% CI, 0.2-2.5] over all follow-up). No differences were observed in patients with rare/absent baseline angina (SAQ Angina Frequency score >80). Among patients with more frequent angina at baseline (SAQ Angina Frequency score <80, 744 patients, 41%), those randomly assigned to INV had a mean 3.7-point higher 19-item Seattle Angina Questionnaire Summary score than conservative strategy (95% CI, 1.6-5.8) with consistent effects across SAQ subscales: Physical Limitations 3.2 points (95% CI, 0.2-6.1), Angina Frequency 3.2 points (95% CI, 1.2-5.1), Quality of Life/Health Perceptions 5.3 points (95% CI, 2.8-7.8). For the Duke Activity Status Index, no difference was estimated overall by treatment, but in patients with baseline SAQ Angina Frequency scores <80, Duke Activity Status Index scores were higher for INV (3.2 points [95% CI, 0.6-5.7]), whereas patients with rare/absent baseline angina showed no treatment-related differences. Moderate to severe depression was infrequent at randomization (11.5%-12.8%) and was unaffected by treatment assignment.

CONCLUSIONS

In the ISCHEMIA comprehensive QOL substudy, patients with more frequent baseline angina reported greater improvements in the symptom, physical functioning, and psychological well-being dimensions of QOL when treated with an invasive strategy, whereas patients who had rare/absent angina at baseline reported no consistent treatment-related QOL differences.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT01471522.

A double-blind randomised placebo-controlled trial of percutaneous coronary intervention for the relief of stable angina without antianginal medications: design and rationale of the ORBITA-2 trial

Percutaneous coronary intervention (PCI) is frequently performed for stable angina. However, the first blinded trial, ORBITA, did not show a placebo-controlled increment in exercise time in patients with single-vessel disease, at 6 weeks, on maximal antianginal therapy. ORBITA-2 will assess the placebo-controlled efficacy of PCI on angina frequency in patients with single- or multivessel disease, at 12 weeks, on no antianginal therapy. ORBITA-2 is a double-blind placebo-controlled trial randomising participants with (i) angina at presentation, (ii) documented angina during the 2-week pre-randomisation symptom assessment phase, (iii) objective evidence of ischaemia, (iv) single- or multivessel disease, and (v) clinical eligibility for PCI. At enrolment, antianginals will be stopped, and angina questionnaires completed. Participants will record their symptoms on a smartphone application daily throughout the trial and will undergo exercise treadmill testing and stress echocardiography at pre-randomisation. They will then undergo coronary angiography with unblinded invasive physiology assessment. Eligible participants will then be sedated to a deep level of conscious sedation and randomised 1:1 between PCI and placebo. After the 12-week blinded follow-up period, they will return for questionnaires, exercise testing and stress echocardiography assessment. If angina becomes intolerable, antianginals will be introduced using a prespecified medication protocol. The primary outcome is an angina symptom score using an ordinal clinical outcome scale for angina. Secondary outcomes include exercise treadmill time, angina frequency, angina severity and quality of life. Trial registration: ClinicalTrials.gov: NCT03742050.

Coronary CT Angiography to Guide Percutaneous Coronary Intervention

Coronary CT angiography (CCTA) has emerged as a powerful noninvasive tool for characterizing the presence, extent, and severity of coronary artery disease (CAD) in patients with stable angina. Recent technological advancements in CT scanner hardware and software have augmented the rich information that can be derived from a single CCTA study. Beyond merely identifying the presence of CAD and assessing stenosis severity, CCTA now allows for the identification and characterization of plaques, lesion length, and fluoroscopic angle optimization, as well as enables the assessment of the physiologic extent of stenosis through CT-derived fractional flow reserve, and may even allow for the prediction of the response to revascularization. These and other features make CCTA capable of not only guiding invasive coronary angiography referral, but also give it the unique ability to help plan coronary intervention. This review summarizes current and future applications of CCTA in procedural planning for percutaneous coronary intervention, provides rationale for wider integration of CCTA in the workflow of the interventional cardiologist, and details how CCTA may help improve patient care and clinical outcomes. Keywords: CT Angiography © RSNA, 2022.

Effectiveness and Tolerability of Trimetazidine 80 Mg Once Daily in Patients with Stable Angina Uncontrolled with Bisoprolol-Based Therapy: The Modus Vivendi Observational Study

Introduction

Modus Vivendi was conducted in routine clinical practice to evaluate the effect of adding trimetazidine 80 mg once daily (TMZ 80 OD) to treat patients with persistent symptoms despite treatment with background antianginal therapies including maximally tolerated bisoprolol.

Methods

This multicenter, prospective, observational, open-label, uncontrolled study recruited adult outpatients with a confirmed diagnosis of stable angina to whom physicians had decided to prescribe TMZ 80 OD. All patients were symptomatic despite treatment, including maximally tolerated doses of bisoprolol. Data on number of angina attacks, use of short-acting nitrates, and quality of life (QoL) were collected at baseline (V1) and at 1-month (V2) and 3-month (V2) follow-up visits. Two sub-analyses assessed efficacy in patients who remained on a stable bisoprolol dose throughout the study, and in patients in whom background antianginal therapy was known.

Results

A total of 1939 patients were recruited (57.2% women). The mean age was 65.6 ± 8.8 years; 73.8% had class II and 26.2% class III angina. At V1, the mean number of angina attacks per week was 6.2 ± 6.5 despite antianginal therapy including maximally tolerated bisoprolol dosage. Following the addition of TMZ 80 OD, this decreased to 3.4 ± 4.2 attacks per week at V2, and 1.6 ± 2.6 at V3 (P < 0.05 at V2 and V3), with concomitant reductions in short-acting nitrate use (P < 0.05). Significant improvements in QoL were observed throughout the study. Subgroup analyses showed that the addition of TMZ 80 OD to guideline-recommended antianginal therapy was associated with significant reductions in the mean number of weekly angina attacks and consumption of short-acting nitrates and improvements in QoL whether patients were treated with maximally tolerated bisoprolol and TMZ 80 OD alone, or maximally tolerated bisoprolol and TMZ 80 OD on top of other antianginal therapies. Treatment was well tolerated.

Conclusion

The study findings support the addition of TMZ 80 OD to bisoprolol with or without other antianginal therapies for patients with persistent angina.

Trial Registration

This study was retrospectively registered under the number ISRCTN29992579.

Quality of Life Assessment in Trials of Revascularization for Chronic Stable Angina: Insights from ORBITA and the Implications of Blinding

The main aims of therapy in chronic stable angina are to reduce the risk of myocardial infarction and death and improve symptoms and quality of life (QoL). Unblinded trials have shown that revascularization does not reduce the risk of myocardial infarction or death but does appear to improve symptoms. However, symptoms are susceptible to the placebo effect which can bias therapies to appear more effective than they are. To assess the true physical impact of a treatment on symptoms, placebo-controlled trials with patients and medical and research teams blinded to treatment allocation are necessary. Symptoms and QoL can be reported directly by the patient or indirectly by the physician. Patient-reported outcome measures in angina trials can include angina frequency, frequency of nitrate use, exercise capacity, and questionnaires such as the Seattle Angina Questionnaire (SAQ) and the generic EuroQOL-5D-5L (EQ-5D-5L) QoL questionnaire. Physician-assessed outcome measures include Canadian Cardiovascular Society Class. The Objective Randomised Blinded Investigation with Optimal Medical Therapy of Angioplasty in Stable Angina (ORBITA) trial was the first blinded placebo-controlled study investigating the role of percutaneous coronary intervention (PCI) in chronic stable angina. The trial showed a smaller than expected and not statistically significant effect of placebo-controlled PCI on the primary endpoint of change in exercise time at 6 weeks follow-up in single-vessel coronary artery disease. There was also no significant placebo-controlled treatment effect of PCI for the prespecified secondary endpoints of SAQ or EQ-5D-5L, although PCI did result in 20% more patients becoming free from angina than placebo in a non-prespecified secondary analysis. ORBITA has demonstrated the need for symptomatic and QoL effects of PCI to be studied using placebo control. Here, we describe ways of measuring QoL, the impact of the unblinded and blinded trials to date, what we have learned from ORBITA, and what is next for this common and complex condition.

Coronary Computed Tomographic Angiography for Complete Assessment of Coronary Artery Disease: JACC State-of-the-Art Review

Coronary computed tomography angiography (CTA) has shown great technological improvements over the last 2 decades. High accuracy of CTA in detecting significant coronary stenosis has promoted CTA as a substitute for conventional invasive coronary angiography in patients with suspected coronary artery disease. In patients with coronary stenosis, CTA-derived physiological assessment is surrogate for intracoronary pressure and velocity wires, and renders possible decision-making about revascularization solely based on computed tomography. Computed tomography coronary anatomy with functionality assessment could potentially become a first line in diagnosis. Noninvasive imaging assessment of plaque burden and morphology is becoming a valuable substitute for intravascular imaging. Recently, wall shear stress and perivascular inflammation have been introduced. These assessments could support risk management for both primary and secondary cardiovascular prevention. Anatomy, functionality, and plaque composition by CTA tend to replace invasive assessment. Complete CTA assessment could provide a 1-stop-shop for diagnosis, risk management, and decision-making on treatment.

Placebo-Controlled Efficacy of Percutaneous Coronary Intervention for Focal and Diffuse Patterns of Stable Coronary Artery Disease

[Figure: see text].

Relief of Ischemia in Ischemic Cardiomyopathy

PURPOSE OF THE REVIEW

Ischemic heart disease is among the most common causes of morbidity and mortality worldwide. In its stable manifestation, obstructing coronary artery stenoses prevent myocardial blood flow from matching metabolic needs of the heart under exercise conditions, which manifests clinically as dyspnea or chest pain. Prolonged bouts of ischemia may result in permanent myocardial dysfunction, heart failure, and eventually reduced survival. The aim of the present work is to review currently available approaches to provide relief of ischemia in stable coronary artery disease (CAD).

RECENT FINDINGS

Several pharmacological and interventional approaches have proven effectiveness in reducing the burden of ischemia in stable CAD and allow for symptom control and quality of life improvement. However, substantial evidence in favor of improved survival with ischemia relief is lacking, and recently published randomized controlled trial suggests that only selected groups of patients may substantially benefit from this approach. Pharmacological treatments aimed at reducing ischemia were shown to significantly reduce ischemic symptoms but failed to provide prognostic benefit. Myocardial revascularization is able to re-establish adequate coronary artery flow and was shown to improve survival in selected groups of patients, i.e., those with significant left main CAD or severe left ventricular dysfunction in multivessel CAD. Outside the previously mentioned categories, revascularization appears to improve symptoms control over medical therapy, but does not confer prognostic advantage. More studies are needed to elucidate the role of systematic invasive functional testing to identify individuals more likely to benefit from revascularization and to evaluate the prognostic role of chronic total occlusion recanalization.

Independent predictors of discordance between the resting full-cycle ratio and fractional flow reserve

The resting full-cycle ratio (RFR), a novel resting index, is well correlated with and shows good diagnostic accuracy to the fractional flow reserve (FFR). However, discordance results between the RFR and FFR have been observed to occur in about 20% of cases. This study aimed to clarify the prevalence and factors of discordant results between the RFR and FFR through a direct comparison of these values in daily clinical practice. A total of 220 intermediate coronary lesions of 156 consecutive patients with RFR and FFR measurements were allocated to four groups according to RFR and FFR cutoff values. We compared the angiographic, clinical, and hemodynamic variables among the groups. Discordant results between the RFR and FFR were observed in 19.6% of vessels, and the proportion of discordant results was significantly higher in the left main trunk and left anterior descending artery (LM + LAD) than in non-LAD vessels (25.2% vs. 12.3%, p = 0.006). In the multivariable regression analysis, LM + LAD location, hemodialysis, and peripheral artery disease were associated with a low RFR among patients with a high FFR. Conversely, the absence of diabetes mellitus and the presence of higher hemoglobin levels were associated with a higher RFR among patients with a low FFR. Specific angiographic and clinical characteristics such as LM + LAD location, hemodialysis, peripheral artery disease, and absence of diabetes mellitus and anemia can be independent predictors of physiologic discordance between the RFR and FFR.

Revascularization decisions in patients with chronic coronary syndromes: Results of the second International Survey on Interventional Strategy (ISIS-2)

BACKGROUND

In chronic coronary syndromes, guidelines mandate invasive functional guidance of revascularization whenever non-invasive proof of ischemia is missing. ISIS-2 survey aimed to evaluate how the adoption of guideline recommendation on ischemia-guided revascularization has evolved over the last 5-7 years.

METHODS

In ISIS-2 participants assessed five complete angiograms, presenting only intermediate stenoses without information on non-invasive pre-testing. Fractional flow reserve was known for each stenosis, but remained undisclosed. Participants could determine stenosis significance either by angiography or by requesting an adjunctive invasive diagnostic method (intravascular imaging or functional tests). Primary endpoint was the rate of requesting adjunctive functional assessment. Secondary endpoints were the rate of concordance between angiography-based decisions and know functional severity. ISIS-2 utilized the same web-based platform as ISIS-1 in 2013. (NCT04001452).

RESULTS

334 participants performed 2059 lesion evaluations: 1202 (59%) decisions were based solely on angiography without expressed need for further evaluation. These decisions were discordant with known functional significance in 39%, mainly with potential of overtreatment. Participants requested invasive functional assessment in 643 (31%) and intravascular imaging in 214 (10%) cases. Compared to ISIS-1 the rate of purely angiography-based decisions has decreased (59% vs 66%; p < 0.001), while invasive functional tests were more frequently requested (31% vs 25%; p < 0.001).

CONCLUSIONS

ISIS-2 suggests an evolving pattern in the intention to integrate invasive coronary physiology into the revascularization decisions. However, the disconnect between recommendations and current thinking is still dominant.

Diagnosis and Management of Stable Angina: A Review

IMPORTANCE

Nearly 10 million US adults experience stable angina, which occurs when myocardial oxygen supply does not meet demand, resulting in myocardial ischemia. Stable angina is associated with an average annual risk of 3% to 4% for myocardial infarction or death. Diagnostic tests and medical therapies for stable angina have evolved over the last decade with a better understanding of the optimal use of coronary revascularization.

OBSERVATIONS

Coronary computed tomographic angiography is a first-line diagnostic test in the evaluation of patients with stable angina due to higher sensitivity and comparable specificity compared with imaging-based stress testing. Moreover, coronary computed tomographic angiography allows detection of nonobstructive atherosclerosis that would not be identified with other noninvasive imaging modalities, improving risk assessment and potentially triggering more appropriate allocation of preventive therapies. Novel therapies treating lipids (proprotein convertase subtilisin/kexin type 9 inhibitors, ezetimibe, and icosapent ethyl) and type 2 diabetes (sodium-glucose cotransporter 2 inhibitors, glucagon-like peptide 1 receptor agonists) have improved cardiovascular outcomes in patients with stable ischemic heart disease when added to usual care. Randomized clinical trials showed no improvement in the rates of mortality or myocardial infarction with revascularization (largely by percutaneous coronary intervention) compared with optimal medical therapy alone, even in the setting of moderate to severe ischemia. In contrast, revascularization provides a meaningful benefit on angina and quality of life compared with antianginal therapies. Measures of the effect of angina on a patient's quality of life should be integrated into the clinic encounter to assist with the decision to proceed with revascularization.

CONCLUSIONS AND RELEVANCE

For patients with stable angina, emphasis should be placed on optimizing lifestyle factors and preventive medications such as lipid-lowering and antiplatelet agents to reduce the risk for cardiovascular events and death. Antianginal medications, such as β-blockers, nitrates, or calcium channel blockers, should be initiated to improve angina symptoms. Revascularization with percutaneous coronary intervention should be reserved for patients in whom angina symptoms negatively influence quality of life, generally after a trial of antianginal medical therapy. Shared decision-making with an informed patient is important for effective treatment of stable angina.

Interpretation of the Seattle Angina Questionnaire as an Outcome Measure in Clinical Trials and Clinical Care: A Review

Importance

Patient-reported outcomes are increasingly used as end points in clinical trials, assessments in clinical care, and tools for population health, with an increasing role in quality assessment. For patients with coronary artery disease, the Seattle Angina Questionnaire (SAQ) has emerged as the most commonly used measure of disease-specific health status to quantify patients' symptoms of angina and the extent to which their angina affects their functioning and quality of life. This review explains how to interpret the SAQ and describes the construction and face validity of the SAQ, focusing on aligning scores and changes in scores with clinical constructs.

Observations

The SAQ asks questions similar to those an experienced clinician would ask of a patient with stable ischemic heart disease. Therefore, SAQ scores can be aligned with clinical constructs (eg, scores on the SAQ angina frequency scale of 0-30 points indicate daily angina, 31-60 points indicate weekly angina, 61-99 points indicate monthly angina, and 100 points indicate no angina), and changes in scores can be described by aligning them with changes in question responses. After clinical thresholds are defined, it is important for clinical trials to not simply report mean differences between treatment arms but to also report the distributions of patients who have had clinically important benefits so that a number needed to treat can be generated.

Conclusions and Relevance

The widespread use of the SAQ is a consequence of its well-established validity, reproducibility, prognostic importance, and sensitivity to clinical change. Nevertheless, interpreting the SAQ can be challenging because of lack of familiarity with the clinical importance of its domains, either cross-sectionally or longitudinally. This review provides an overview of the interpretability of the SAQ as a foundation for its use as an end point in clinical trials, a tool to support more patient-centered care, and a means of facilitating population health strategies to provide a better foundation for the integration of patient experiences with clinical care.

Optimising physiological endpoints of percutaneous coronary intervention

Invasive coronary physiology to select patients for coronary revascularisation has become established in contemporary guidelines for the management of stable coronary artery disease. Compared to revascularisation based on angiography alone, the use of coronary physiology has been shown to improve clinical outcomes and cost efficiency. However, recent data from randomised controlled trials have cast doubt upon the value of ischaemia testing to select patients for revascularisation. Importantly, 20-40% of patients have persistence or recurrence of angina after angiographically successful percutaneous coronary intervention (PCI). This state-of-the-art review is focused on the transitioning role of invasive coronary physiology from its use as a dichotomous test for ischaemia with fixed cut-points, towards its utility for real-time guidance of PCI to optimise physiological results. We summarise the contemporary evidence base for ischaemia testing in stable coronary artery disease, examine emerging indices which allow advanced physiological guidance of PCI, and discuss the rationale and evidence base for post-PCI physiological assessments to assess the success of revascularisation.

Clinical implications and debates on the ISCHEMIA trial

The ISCHEMIA was eagerly awaited study in the field of ischemic heart disease. Following the presentation and publication of ISCHEMIA, multiple opinions and viewpoints get complicated. The ongoing debates have been including the relevance of coronary revascularization, non-invasive diagnostic methods, and invasive ischemic testing in patients with stable ischemic heart disease (SIHD). Prior to ISCHEMIA, observational studies indicated the potential of coronary revascularization for improving clinical outcomes, while the randomized COURAGE trial did not support the plausible concept. Although the FAME 2 trial implied the superiority of percutaneous coronary intervention over medical therapy alone, the clinical relevance of coronary revascularization to improve outcomes and quality of life has been questioned. As a consequence, the ISCHEMIA trial did not demonstrate clear benefits in reducing clinical events but showed antianginal effects of revascularization. This landmark trial also suggested the difficulties of non-invasive ischemia testing rather than computed tomography angiography. Despite the complex results, the ISCHEMIA trial may simplify the clinical indications of coronary revascularization in patients with SIHD. Future publications from the ISCHEMIA trial and debates on the results will sharpen our thinking and understanding.

Controversies in revascularisation for stable coronary artery disease

Recent randomised controlled trials, such as ISCHEMIA and ORBITA, have overturned most of what we were taught in medical school about hospital procedures considered necessary for patients with stable coronary artery disease. In this article, we discuss what these trials mean for physicians and patients considering revascularisation procedures with the hope of reducing the risk of death or alleviating angina.

Physiology-Based Revascularization of Left Main Coronary Artery Disease

It is of critical importance to correctly assess the significance of a left main lesion. Underestimation of significance beholds the risk of inappropriate deferral of revascularization, whereas overestimation may trigger major but unnecessary interventions. This article addresses the invasive physiological assessment of left main disease and its role in deciding upon revascularization. It mainly focuses on the available evidence for fractional flow reserve and instantaneous wave-free ratio, their interpretation, and limitations. We also discuss alternative invasive physiological indices and imaging, as well as the link between physiology, ischemia, and prognosis.

Achieving Optimal Medical Therapy: Insights From the ORBITA Trial

Background

In stable coronary artery disease, medications are used for 2 purposes: cardiovascular risk reduction and symptom improvement. In clinical trials and clinical practice, medication use is often not optimal. The ORBITA (Objective Randomised Blinded Investigation With Optimal Medical Therapy of Angioplasty in Stable Angina) trial was the first placebo‐controlled trial of percutaneous coronary intervention. A key component of the ORBITA trial design was the inclusion of a medical optimization phase, aimed at ensuring that all patients were treated with guideline‐directed truly optimal medical therapy. In this study, we report the medical therapy that was achieved.

Methods and Results

After enrollment into the ORBITA trial, all 200 patients entered a 6‐week period of intensive medical therapy optimization, with initiation and uptitration of risk reduction and antianginal therapy. At the prerandomization stage, the median number of antianginals established was 3 (interquartile range, 2–4). A total of 195 patients (97.5%) reached the prespecified target of ≥2 antianginals; 136 (68.0%) did not stop any antianginals because of adverse effects, and the median number of antianginals stopped for adverse effects per patient was 0 (interquartile range, 0–1). Amlodipine and bisoprolol were well tolerated (stopped for adverse effects in 4/175 [2.3%] and 9/167 [5.4%], respectively). Ranolazine and ivabradine were also well tolerated (stopped for adverse effects in 1/20 [5.0%] and 1/18 [5.6%], respectively). Isosorbide mononitrate and nicorandil were stopped for adverse effects in 36 of 172 (20.9%) and 32 of 141 (22.7%) of patients, respectively. Statins were well tolerated and taken by 191 of 200 (95.5%) patients.

Conclusions

In the 12‐week ORBITA trial period, medical therapy was successfully optimized and well tolerated, with few drug adverse effects leading to therapy cessation. Truly optimal medical therapy can be achieved in clinical trials, and translating this into longer‐term clinical practice should be a focus of future study.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02062593.

Stable ischemic heart disease: re-appraisal of coronary revascularization criteria in the light of contemporary evidence

The term "stable ischemic heart disease" includes a variety of clinical and pathophysiological situations resulting in different presentation modalities, often with complex referral patterns, and with multiple potential therapeutical options. Multifactorial pathogenesis and multiform expressivity are poorly captured by the traditional vision of ischemic heart disease (IHD) as the clogged pipes disease. The availability of different technologies for studying patients with symptoms suggestive of IHD, has shed a new light on the pathophysiology of the disease, but has also allowed appropriate follow-up of patients allocated to different therapeutical options. Though coronary revascularization has been one primary treatment option for obstructive coronary artery disease (CAD), the evidence for its efficacy in patients without acute presentation is far from optimal. A number of studies and meta-analyses strongly support the need for a personalized and optimized medical approach (including functional assessment and therapy) before the tailored option of revascularization in selected patients, in order to optimize its effects on symptoms and outcome. Most recent data have expanded the need for a more personalised approach to this complex situation, which should be patient-centered and not focused on technologies. In this review, we discuss the major pathophysiological factors and the most recent clinical data and guidelines suggestions, needed for a critical re-appraisal of the clinical decision-making to perform revascularization in patients with stable IHD. Moreover we aimed at suggesting the potential role for future studies to fill the existing knowledge gaps but also to counteract a reductive, hydraulic view of chronic IHD, which seems to be still alive and kicking, both in clinical and research communities, despite multiple evidences and recommendations.

Gender-Related Differences in Clinical Presentation and Angiographic Findings in Patients with Ischemia and No Obstructive Coronary Artery Disease (INOCA): A Single-Center Observational Registry

Ischemia and no obstructive coronary arteries (INOCA) is a common clinical presentation, with a variety of causes that are often not fully investigated in routine clinical practice. The goal of our study was to characterize a real-world population of patients with INOCA, with a deeper focus on symptoms and stress test findings. The study population consisted of 435 patients who underwent diagnostic coronary angiography for anginal symptoms and/or evidence of myocardial ischemia at non-invasive imaging. In all patients angiography demonstrated nonobstructive coronary artery disease (CAD, less than 30% luminal diameter stenosis or fractional flow reserve > 0.8 and/or instantaneous wave-free ratio  > 0.89). Fifty-four percent of the patients were women. Atypical clinical presentation was more common in women (59.5 vs. 49.5%, p = 0.037). Women were more likely to have normal coronary arteries than men (41.8 vs. 16.2%, p < 0.001), and less likely than men to have hemodynamically non-significant CAD (32.1 vs. 55.1%, p < 0.001). No significant correlation between typicality of symptoms and evidence of ischemia was found in those patients (244/435, 56.1%) who had either dobutamine stress echocardiography or electrocardiogram stress test. INOCA is a common clinical condition, prevalent in women often presenting with atypical symptoms.

Two-Year Outcomes of Asymptomatic vs. Symptomatic Patients After Deferral of Revascularization Based on Fractional Flow Reserve - Insights From the J-CONFIRM Registry

Background: The effect of symptoms on clinical outcomes after deferral of revascularization based on fractional flow reserve (FFR) remains poorly understood. Methods and Results: From the J-CONFIRM (Long-Term Outcomes of Japanese Patients With Deferral of Coronary Intervention Based on Fractional Flow Reserve in Multicenter) Registry, this study evaluated 1,215 patients with stable coronary artery disease, including symptomatic and asymptomatic patients (n=571 and 644, respectively). The primary endpoint was the cumulative 2-year incidence of target vessel failure (TVF), including cardiac death, target vessel-related myocardial infarction (TVMI), and clinically driven target vessel revascularization (CDTVR). An inverse probability weighted analysis was performed to adjust for the differences in baseline clinical characteristics between the 2 groups. At 2 years, the TVF rate did not differ significantly between symptomatic and asymptomatic patients (6.5% vs. 4.9%, respectively; P=0.15) or between symptomatic and asymptomatic patients with lesions with an FFR ≤0.80 (8.0% vs. 12.3%, respectively; P=0.20). Conversely, symptomatic patients showed significantly higher rates of TVF (6.2% vs. 3.3%; P=0.01) and CDTVR (6.2% vs. 3.1%; P=0.009) than asymptomatic patients, regardless of negative FFR values (>0.80). Conclusions: Despite negative FFR values, symptomatic patients were at higher risk of TVF than asymptomatic patients, driven primarily by a higher rate of CDTVR. Conversely, those with a positive FFR were likely to develop TVF regardless of their symptoms.

Clinical Cardiovascular Applications of Hyperpolarized Magnetic Resonance

Current cardiovascular magnetic resonance imaging techniques provide an exquisite assessment of the structure and function of the heart and great vessels, but their ability to assess the molecular processes that underpin changes in cardiac function in health and disease is limited by inherent insensitivity. Hyperpolarized magnetic resonance is a new technology which overcomes this limitation, generating molecular contrast agents with an improvement in magnetic resonance signal of up to five orders of magnitude. One key molecule, hyperpolarized [1-¹³C]pyruvate, shows particular promise for the assessment of cardiac energy metabolism and other fundamental biological processes in cardiovascular disease. This molecule has numerous potential applications of clinical relevance and has now been translated to human use in early clinical studies. This review outlines the principles of hyperpolarized magnetic resonance and key potential cardiovascular applications for this new technology. Finally, we provide an overview of the pipeline for forthcoming hyperpolarized agents and their potential applications in cardiovascular disease.

COURAGE, ORBITA, and ISCHEMIA: Percutaneous Coronary Intervention for Stable Coronary Artery Disease

This review article summarizes key landmark trials that have shaped understanding of the role of percutaneous coronary intervention (PCI) in stable coronary artery disease (CAD). The relationship between stenosis, ischemia, and angina is more complex than first imagined. Anginal relief remains the primary indication for PCI in stable CAD. The first placebo-controlled PCI trial showed a surprisingly small effect size, suggesting a significant placebo effect. PCI in stable CAD has not been shown to improve mortality or overall myocardial infarction rates, even in the presence of significant ischemia. Rather, risk reduction medical therapy remains the main intervention for improving outcomes.

Mechanisms and diagnostic evaluation of persistent or recurrent angina following percutaneous coronary revascularization

Persistence or recurrence of angina after a percutaneous coronary intervention (PCI) may affect about 20-40% of patients during short-medium-term follow-up. This appears to be true even when PCI is 'optimized' using physiology-guided approaches and drug-eluting stents. Importantly, persistent or recurrent angina post-PCI is associated with a significant economic burden. Healthcare costs may be almost two-fold higher among patients with persistent or recurrent angina post-PCI vs. those who become symptom-free. However, practice guideline recommendations regarding the management of patients with angina post-PCI are unclear. Gaps in evidence into the mechanisms of post-PCI angina are relevant, and more research seems warranted. The purpose of this document is to review potential mechanisms for the persistence or recurrence of angina post-PCI, propose a practical diagnostic algorithm, and summarize current knowledge gaps.

Lessons Learnt from Recent Trials in Ischemic Heart Disease

Four recently published randomized controlled trials have informed the care of patients with stable ischemic heart disease. The purpose of this clinical focus article is to offer a summary and critical appraisal of the recent evidence. We aim to aid clinicians in the translation of the trial evidence to patient care.

The State of Percutaneous Intervention in Stable Coronary Artery Disease

PURPOSE OF REVIEW

This review examines trials of percutaneous coronary intervention (PCI) compared with optimal medical therapy (OMT) in order to inform clinical decision-making regarding the role of PCI in stable ischemic heart disease (SIHD).

RECENT FINDINGS

Several large, randomized, controlled trials published in recent years suggest that OMT should be the initial treatment strategy for symptomatic SIHD, but there is a role for PCI in patients who continue to be symptomatic despite OMT. Additionally, using fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) techniques may help to identify physiologically significant lesions and may be useful in maximizing the benefit from PCI in SIHD. Recent trials demonstrate PCI for the treatment of symptomatic SIHD does not reduce mortality compared with OMT but effectively relieves anginal symptoms. However, OMT continues to be the first-line therapy for SIHD but is significantly underutilized.