Fractional Flow Reserve-Negative High-Risk Plaques and Clinical Outcomes After Myocardial Infarction.

Importance: Even after fractional flow reserve (FFR)-guided complete revascularization, patients with myocardial infarction (MI) have high rates of recurrent major adverse cardiovascular events (MACE). These recurrences may be caused by FFR-negative high-risk nonculprit lesions. Objective: To assess the association between optical coherence tomography (OCT)-identified high-risk plaques of FFR-negative nonculprit lesions and occurrence of MACE in patients with MI. Design, Setting, and Participants: PECTUS-obs (Identification of Risk Factors for Acute Coronary Events by OCT After STEMI [ST-segment elevation MI] and NSTEMI [non-STEMI] in Patients With Residual Non-flow Limiting Lesions) is an international, multicenter, prospective, observational cohort study. In patients presenting with MI, OCT was performed on all FFR-negative (FFR > 0.80) nonculprit lesions. A high-risk plaque was defined containing at least 2 of the following prespecified criteria: (1) a lipid arc at least 90°, (2) a fibrous cap thickness less than 65 µm, and (3) either plaque rupture or thrombus presence. Patients were enrolled from December 14, 2018, to September 15, 2020. Data were analyzed from December 2, 2022, to June 28, 2023. Main Outcome and Measure: The primary end point of MACE, a composite of all-cause mortality, nonfatal MI, or unplanned revascularization, at 2-year follow-up was compared in patients with and without a high-risk plaque. Results: A total of 438 patients were enrolled, and OCT findings were analyzable in 420. Among included patients, mean (SD) age was 63 (10) years, 340 (81.0) were men, and STEMI and non-STEMI were equally represented (217 [51.7%] and 203 [48.3%]). A mean (SD) of 1.17 (0.42) nonculprit lesions per patient was imaged. Analysis of OCT images revealed at least 1 high-risk plaque in 143 patients (34.0%). The primary end point occurred in 22 patients (15.4%) with a high-risk plaque and 23 of 277 patients (8.3%) without a high-risk plaque (hazard ratio, 1.93 [95% CI, 1.08-3.47]; P = .02), primarily driven by more unplanned revascularizations in patients with a high-risk plaque (14 of 143 [9.8%] vs 12 of 277 [4.3%]; P = .02). Conclusions and Relevance: Among patients with MI and FFR-negative nonculprit lesions, the presence of a high-risk plaque is associated with a worse clinical outcome, which is mainly driven by a higher number of unplanned revascularizations. In a population with a high recurrent event rate despite physiology-guided complete revascularization, these results call for research on additional pharmacological or focal treatment strategies in patients harboring high-risk plaques.

Identification of anatomic risk factors for acute coronary events by optical coherence tomography in patients with myocardial infarction and residual nonflow limiting lesions: rationale and design of the PECTUS-obs study.

INTRODUCTION: In patients with myocardial infarction, the decision to treat a nonculprit lesion is generally based on its physiological significance. However, deferral of revascularisation based on nonischaemic fractional flow reserve (FFR) values in these patients results in less favourable outcomes compared with patients with stable coronary artery disease, potentially caused by vulnerable nonculprit lesions. Intravascular optical coherence tomography (OCT) imaging allows for in vivo morphological assessment of plaque 'vulnerability' and might aid in the detection of FFR-negative lesions at high risk for recurrent events. METHODS AND ANALYSIS: The PECTUS-obs study is an international multicentre prospective observational study that aims to relate OCT-derived vulnerable plaque characteristics of nonflow limiting, nonculprit lesions to clinical outcome in patients with myocardial infarction. A total of 438 patients presenting with myocardial infarction (ST-elevation myocardial infarction and non-ST-elevation myocardial infarction) will undergo OCT-imaging of any FFR-negative nonculprit lesion for detection of plaque vulnerability. The primary study endpoint is a composite of major adverse cardiovascular events (all-cause mortality, nonfatal myocardial infarction or unplanned revascularisation) at 2-year follow-up. Secondary endpoints will be the same composite at 1-year and 5-year follow-up, target vessel failure, target vessel revascularisation, target lesion failure and target lesion revascularisation. ETHICS AND DISSEMINATION: This study has been approved by the Medical Ethics Committee of the region Arnhem-Nijmegen. The results of this study will be disseminated in a main paper and additional papers with subgroup analyses. TRIAL REGISTRATION NUMBER: NCT03857971.

Hand Sensibility after Transradial Arterial Access: An Observational Study in Patients with and without Radial Artery Occlusion.

PURPOSE: To evaluate hand sensibility after transradial access (TRA) in patients with and without radial artery occlusion (RAO). MATERIALS AND METHODS: In this study, 71 patients with and without RAO after TRA for a coronary intervention were studied (79% male, mean age 65 y ± 9). Sensibility testing of both hands was performed with the Semmes-Weinstein monofilaments test. The primary endpoint was abnormal sensibility, defined as diminished sensibility in at least 1 radial nerve-supplied dermatome. The contralateral hand served as control. The influence of TRA, RAO, and clinical characteristics on hand sensibility was evaluated. RESULTS: In patients with RAO, more abnormal sensibility was observed on the RAO side compared with the control hand (72% vs 17%, P < .01). In patients without RAO, more abnormal sensibility was observed in the TRA hand compared with the control hand (43% vs 10%, P < .01). When analyzing all hands separately, TRA, RAO, and diabetes were independent predictors for abnormal hand sensibility in a multivariate model (odds ratio 3.8, 95% confidence interval 1.4-9.8, P < .01; odds ratio 3.0, 95% confidence interval 1.1-8.5, P = .03; odds ratio 3.5, 95% confidence interval 1.4-8.6, P < .01). CONCLUSIONS: TRA and RAO are associated with diminished hand sensibility.

ACRA Perfusion Study.

BACKGROUND: Transradial intervention (TRI) may impair digital perfusion with hand dysfunction as a result. However, the effect of TRI on digital perfusion has never been investigated, including the influence of variations of the collateral arterial network and the effect on hand dysfunction. METHODS AND RESULTS: We investigated the effect of TRI on digital perfusion by laser Doppler perfusion imaging. Laser Doppler perfusion imaging was performed at baseline, during radial access, TR band application, and at discharge. We compared tissue perfusion of the homolateral thumb (access site) with the contralateral thumb (comparator) during radial access as primary outcome. The hand circulation was assessed with angiography. Upper extremity function was evaluated with the validated QuickDASH questionnaire at baseline and follow-up. A significant reduction of tissue perfusion was observed during radial access and TR band application in the homolateral thumb (-32%, -32%, respectively) and contralateral thumb (-34%, -21%, respectively). We detected no perfusion difference between the homolateral and contralateral thumb during radial access (217; interquartile range, 112-364 versus 209; interquartile range, 99-369 arbitrary flux units; P=0.59). Reduced perfusion of the thumb during radial access was not associated with incompleteness of the superficial palmar arch ( P=0.13). Digital perfusion improved at discharge, though it remained below baseline levels (homolateral -11% and contralateral -14%). Hand dysfunction at 18 months was not associated with TRI-induced perfusion reduction ( P=0.54). CONCLUSIONS: TRI is safe. Digital perfusion is reduced in both hands during radial access and TR band application but is not associated with future loss of hand function and variations of the arterial hand supply.

Chronic radial artery occlusion does not cause exercise induced hand ischemia.

OBJECTIVES: The aim of the study was to evaluate the occurrence of hand ischemia in patients with radial artery occlusion (RAO), using the contralateral hand as control. BACKGROUND: Radial artery occlusion is a common complication (6%) after transradial access (TRA) but rarely leads to major ischemic events due to the collateral perfusion of the hand. However, it has been reported that RAO can become symptomatic, possibly as a consequence of hand ischemia. To evaluate the existence of exercise induced hand ischemia in patients with RAO, we initiated the present study. METHODS: After a transradial coronary procedure, patients with suspicion of RAO were asked for study participation. After informed consent, radial ultrasound was performed. In patients with confirmed RAO, rest perfusion of the digits was analyzed by laser Doppler digital imaging. Occurrence of ischemia during exercise was assessed with transcutaneous oxygen pressure (TcPO2) and thumb capillary lactate. All analyses were performed in both the RAO side as well as the contralateral side as control. RESULTS: RAO occlusion was confirmed in 18 patients. After 5 min of exercise there were no significant differences in TcPO2 (51.4 mmHg [±17.2] vs 43.9 mmHg [±15.5], P = 0.18) or lactate (2.0 mmol/L [±0.7] vs 2.1 mmol/L [±0.7], P = 0.80) between RAO side and control side. Differences in mean TcPO2 were found to be stable during exercise and not different from baseline differences. CONCLUSIONS: Chronic radial artery occlusion does not lead to exercise induced hand ischemia.

The ACRA Anatomy Study (Assessment of Disability After Coronary Procedures Using Radial Access): A Comprehensive Anatomic and Functional Assessment of the Vasculature of the Hand and Relation to Outcome After Transradial Catheterization.

BACKGROUND: The palmar arches serve as the most important conduits for digital blood supply, and incompleteness may lead to digital ischemia when the radial artery becomes obstructed after cardiac catheterization. The rate of palmar arch incompleteness and the clinical consequences after transradial access are currently unknown. METHODS AND RESULTS: The vascular anatomy of the hand was documented by angiography in 234 patients undergoing transradial cardiac catheterization. In all patients, a preprocedural modified Allen test and Barbeau test were performed. Upper-extremity function was assessed at baseline and 2-year follow-up by the QuickDASH. Incompleteness of the superficial palmar arch (SPA) was present in 46%, the deep palmar arch was complete in all patients. Modified Allen test and Barbeau test results were associated with incompleteness of the SPA (P=0.001 and P=0.001). The modified Allen test had a 33% sensitivity and 86% specificity for SPA incompleteness with a cutoff value of >10 seconds and a 59% sensitivity and 60% specificity with a cutoff value of >5 seconds. The Barbeau test had a 7% sensitivity and 98% specificity for type D and a 21% sensitivity and 93% specificity for types C and D combined. Upper-extremity dysfunction was not associated with SPA incompleteness (P=0.77). CONCLUSIONS: Although incompleteness of the SPA is common, digital blood supply is always preserved by a complete deep palmar arch. Preprocedural patency tests have thus no added benefit to prevent ischemic complications of the hand. Finally, incompleteness of the SPA is not associated with a loss of upper-extremity function after transradial catheterization.

Body Mass Index Is Associated With Microvascular Endothelial Dysfunction in Patients With Treated Metabolic Risk Factors and Suspected Coronary Artery Disease.

BACKGROUND: Obesity is key feature of the metabolic syndrome and is associated with high cardiovascular morbidity and mortality. Obesity is associated with macrovascular endothelial dysfunction, a determinant of outcome in patients with coronary artery disease. Here, we compared the influence of obesity on microvascular endothelial function to that of established cardiovascular risk factors such as diabetes mellitus, hypertension, hypercholesterolemia, and smoking in patients with suspected coronary artery disease. METHODS AND RESULTS: Endothelial function was assessed during postocclusive reactive hyperemia of the brachial artery and downstream microvascular beds in 108 patients who were scheduled for coronary angiography. In all patients, microvascular vasodilation was assessed using peripheral arterial tonometry; laser Doppler flowmetry and digital thermal monitoring were performed. Body mass index was significantly associated with decreased endothelium-dependent vasodilatation measured with peripheral arterial tonometry (r=0.23, P=0.02), laser Doppler flowmetry (r=0.30, P<0.01), and digital thermal monitoring (r=0.30, P<0.01). In contrast, hypertension, hypercholesterolemia, and smoking had no influence on microvascular vasodilatation. Especially in diabetic patients, endothelial function was not significantly reduced (control versus diabetes mellitus, mean±SEM or median [interquartile range], peripheral arterial tonometry: 1.90±0.20 versus 1.67±0.20, P=0.19, laser Doppler flowmetry: 728% [interquartile range, 427-1110] versus 589% [interquartile range, 320-1067] P=0.28, and digital thermal monitoring: 6.6±1.0% versus 2.5±1.7%, P=0.08). In multivariate linear regression analysis, body mass index was the only risk factor that significantly attenuated endothelium-dependent vasodilatation using all 3 microvascular function tests. CONCLUSIONS: Higher body mass index is associated with reduced endothelial function in patients with suspected coronary artery disease, even after adjustment for treated diabetes mellitus, hypertension, hypercholesterolemia, and smoking.

Early Detection and Treatment of the Vulnerable Coronary Plaque: Can We Prevent Acute Coronary Syndromes?

Early identification and treatment of the vulnerable plaque, that is, a coronary artery lesion with a high likelihood of rupture leading to an acute coronary syndrome, have gained great interest in the cardiovascular research field. Postmortem studies have identified clear morphological characteristics associated with plaque rupture. Recent advances in invasive and noninvasive coronary imaging techniques have empowered the clinician to identify suspected vulnerable plaques in vivo and paved the way for the evaluation of therapeutic agents targeted at reducing plaque vulnerability. Local treatment of vulnerable plaques by percutaneous coronary intervention and systemic treatment with anti-inflammatory and low-density lipoprotein-lowering drugs are currently being investigated in large randomized clinical trials to assess their therapeutic potential for reducing adverse coronary events. Results from these studies may enable a more patient-tailored strategy for the treatment of coronary artery disease.

The long-term effect of transradial coronary catheterisation on upper limb function.

AIMS: Anatomic and physiologic changes that are induced by radial access may lead to a decrease of upper limb function at long-term follow-up; however, this has never been studied. We aimed to study the long-term effect of transradial catheterisation on upper limb function. METHODS AND RESULTS: Between January 2013 and April 2014, upper limb function was assessed in a total of 348 patients with complete one-year follow-up after coronary catheterisation. Upper limb function was assessed with the self-reported shortened version of the DASH questionnaire. The presence and severity of upper extremity cold intolerance was assessed with the self-reported CISS questionnaire. Both questionnaires were completed before the catheterisation and at one-year follow-up. Higher scores represent worse upper limb functionality or symptoms. The non-parametric Wilcoxon signed-rank test was used to assess the change of upper limb function and symptoms over time. Extremity complaints were reported at one-month and one-year follow-up. At one-year follow-up, upper limb function did not change over time when catheterisation was performed through the radial artery (p-value 0.20). Upper extremity was also not affected by cold intolerance at one-year follow-up (p-value 0.09). Extremity complaints were reported equally in both access groups and diminished significantly over time (p-value <0.001). CONCLUSIONS: Upper limb function was not affected at long-term follow-up after transradial procedures.

Non-invasive assessment of the collateral circulation in the hand: validation of the Nexfin system and relation to clinical outcome after transradial catheterisation.

AIMS: This study aims primarily to assess the extent of the collateral circulation of the hand in a combined population of healthy individuals and patients who underwent transradial catheterisation, using both the Nexfin system and laser Doppler perfusion imaging. METHODS AND RESULTS: In total, 85 adults were included in the study (18 healthy volunteers; 67 patients who underwent transradial catheterisation). The perfusion of the thumb was assessed prior to and during complete radial artery compression using laser Doppler perfusion imaging (LDPI) and the Nexfin system. The palmar collateral flow index (PCFI) was compared between both devices and PCFINEXFIN was related to hand angiography and the upper limb function, using the QuickDASH questionnaire. Mean PCFILDPI was 0.77±0.15 and mean PCFINEXFIN was 0.88±0.08. Both were significantly related (Pearson correlation=0.49, 95% CI: 0.31-0.64, p<0.001, agreement -0.11±0.13). PCFINEXFIN correlated with the maximal diameter of the superficial palmar arch (R=0.49, p=0.04) and total minimal arch diameter (R=0.51, p<0.02). High PCFINEXFIN, measured at baseline, was correlated with a lower QuickDASH score for pain, activity and total at one month post transradial catheterisation (p=0.02, p<0.01, p<0.01), but not with discomfort or disability. CONCLUSIONS: The Nexfin monitoring system is comparable with laser Doppler perfusion imaging in the quantification of the collateral perfusion in the hand. In patients, the Nexfin-derived collateral flow index measured at baseline is associated with clinical outcome at 30 days post transradial catheterisation.

Lack of efficacy of clopidogrel pre-treatment in the prevention of myocardial damage after elective stent implantation.

OBJECTIVES: The object of this study was to determine the effect of pre-treatment with clopidogrel in patients undergoing elective stent implantation. BACKGROUND: The treatment of patients with adenosine diphosphate receptor blockers after percutaneous coronary intervention (PCI) with stent implantation has been shown to decrease the incidence of subacute stent thrombosis. Furthermore, non-randomized studies on pre-treatment with clopidogrel among patients undergoing stent implantation have suggested a reduction in myocardial damage and clinical events. The effect of pre-treatment with clopidogrel has been studied in only a few randomized trials. METHODS: In a randomized trial, three days of pre-treatment with clopidogrel was compared with standard post-procedural treatment in 203 patients undergoing elective stent implantation. The primary end point was a rise in troponin I or creatine kinase-MB fraction (CK-MB) serum levels at 6 to 8 and 16 to 24 h after PCI. Secondary end points were death, stroke, myocardial infarction, coronary bypass grafting, repeated PCI, and subacute stent thrombosis at one and six months after PCI. RESULTS: No difference was found between non-pre-treated and pre-treated patients in the post-procedural elevation of troponin I (42 [43.3%] vs. 48 [51.1%], respectively, p = 0.31) or CK-MB (6 [6.3%] vs. 7 [7.4%], respectively, p = 0.78). Adjustment for possible confounding factors did not change these findings. Patient follow-up at one and six months showed no significant difference between the treatment groups in death, stroke, myocardial infarction, coronary artery bypass grafting, repeated PCI, or subacute stent thrombosis. CONCLUSIONS: In this randomized study, no beneficial effect of pre-treatment with clopidogrel on post-procedural elevation of troponin I and CK-MB or on clinical events after one and sixth months could be demonstrated. The study suggests that among patients with stable coronary syndromes in whom coronary stent implantation is planned, pre-treatment may not be beneficial in reducing early myocardial damage.