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Despite prompt epicardial recanalization in patients presenting with ST-segment elevation myocardial infarction (STEMI), coronary microvascular obstruction and dysfunction (CMVO) is still fairly common and is associated with poor prognosis. Various pharmacological and mechanical strategies to treat CMVO have been proposed, but the positive results reported in preclinical and small proof-of-concept studies have not translated into benefits in large clinical trials conducted in the modern treatment setting of patients with STEMI. Therefore, the optimal management of these patients remains a topic of debate. In this Review, we appraise the pathophysiological mechanisms of CMVO, explore the evidence and provide future perspectives on strategies to be implemented to reduce the incidence of CMVO and improve prognosis in patients with STEMI., (© 2023. Springer Nature Limited.)

Background and Aims: Acetylcholine (ACh) provocation testing can detect vasomotor disorders in patients with ischemia and non-obstructed coronary arteries (INOCA) or myocardial infarction and non-obstructed coronary arteries (MINOCA). We aimed to derive and validate a simple risk score to predict a positive ACh test response., Methods: We prospectively enrolled consecutive INOCA and MINOCA patients undergoing ACh provocation testing. Patients were split in two cohorts (derivation and validation) according to time of enrolment. The score was derived in 386 patients (derivation cohort) and then validated in 165 patients (validation cohort)., Results: 551 patients were enrolled, 371 (67.3%) INOCA and 180 (32.7%) MINOCA. ACh test was positive in 288 (52.3%) patients. MINOCA, myocardial bridge (MB), C-reactive protein (CRP) and dyslipidaemia were independent predictors of a positive ACh test in the derivation cohort. The ABCD (Acute presentation, Bridge, CRP, Dyslipidaemia) score was derived: 2 points were assigned to MINOCA, 3 to MB, 1 to elevated CRP and 1 to dyslipidaemia. The ABCD score accurately identified patients with a positive ACh test response with an AUC of 0.703 (CI 95% 0.652-0.754,p < 0.001) in the derivation cohort, and 0.705 (CI 95% 0.626-0.784, p < 0.001) in the validation cohort. In the whole population, an ABCD score ≥4 portended 94.3% risk of a positive ACh test and all patients with an ABCD score ≥6 presented a positive test., Conclusions: The ABCD score could avoid the need of ACh provocation testing in patients with a high score, reducing procedural risks, time, and costs, and allowing the implementation of a tailored treatment strategy. These results are hypothesis generating and further research involving larger cohorts and multicentre trials is needed to validate and refine the ABCD score., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Aims: Coronary artery ectasia (CAE) has been linked to the occurrence of adverse events in patients with ischemia/angina and no obstructive coronary arteries (INOCA/ANOCA), while the relationship between CAE and myocardial infarction with nonobstructive coronary arteries (MINOCA) has been poorly investigated. In our study we aimed at assessing differences in clinical, angiographic and prognostic features among patients with CAE and MINOCA vs. INOCA/ANOCA presentation., Methods: Patients with angiographic evidence of CAE were enrolled at the University Hospital of Parma and divided into MINOCA vs. INOCA/ANOCA presentation. Clinical and quantitative angiographic information was recorded and the incidence of major adverse cardiovascular events (MACE) was assessed at follow-up., Results: We enrolled a total of 97 patients: 49 (50.5%) with MINOCA and 48 (49.5%) with INOCA/ANOCA presentation. The presentation with MINOCA was associated with a higher frequency of inflammatory diseases ( P  = 0.041), multivessel CAE ( P  = 0.030) and thrombolysis in myocardial infarction (TIMI) flow < 3 ( P  = 0.013). At a median follow-up of 38 months, patients with MINOCA had a significantly higher incidence of MACE compared with those with INOCA/ANOCA [8 (16.3%) vs. 2 (4.2%), P  = 0.045], mainly driven by a higher rate of nonfatal MI [5 (10.2%) vs. 0 (0.0%), P  = 0.023]. At multivariate Cox regression analysis, the presentation with MINOCA ( P  = 0.039) and the presence of TIMI flow <3 ( P  = 0.037) were independent predictors of MACE at follow-up., Conclusion: Among a cohort of patients with CAE and nonobstructive coronary artery disease, the presentation with MINOCA predicted a worse outcome., (Copyright © 2024 Italian Federation of Cardiology - I.F.C. All rights reserved.)

Recent randomized trials comparing coronary artery bypass graft (CABG) with percutaneous coronary intervention (PCI) utilizing drug-eluting stents in patients with left main disease (LMD) and/or multivessel disease (MVD), reported conflicting results. We performed a study level meta-analysis comparing the 2 interventions for the treatment of LMD or MVD. Using electronic databases, we retrieved 6 trials, between January, 2010 and December, 2022. Five-years Kaplan-Meier curves of endpoints where reconstructed. Comparisons were made by cox-linear regression frailty model and by landmark analysis. A random-effect method was applied. A total of 8269 patients were included and randomly assigned to CABG (n = 4135) or PCI (n = 4134). During 5-years follow-up, PCI showed a higher incidence of all-cause mortality (hazard ratio [HR] 1.28; 95% confidence interval [CI], 1.11-1.47; P < 0.0001]), myocardial infarction (HR 1.84; 95% CI, 1.54-2.19; P < 0.0001) and repeat coronary revascularization (HR 1.96; 95% CI, 1.72-2.24; P < 0.0001). There was no long-term difference between the 2 interventions for cardiovascular death (P = 0.14) and stroke (P = 0.20), although the incidence of stroke was higher with CABG within 30-days from intervention (P < 0.0001). PCI was associated with an increased risk for composite endpoints (P < 0.0001) and major cerebral and cardiovascular events. (P < 0.0001). In conclusion, at 5-year follow-up, in patients with LMD and/or MVD there was a significant higher incidence of all-cause mortality, myocardial infarction and repeat revascularization with PCI compared to CABG. The incidence of stroke was higher with CABG during the postprocedural period, but no difference was found during 5-years follow-up. Longer follow-up is mandatory to better define outcome difference between the 2 interventions., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Introduction: Composite endpoints are pivotal when assessing rare outcomes over relatively short follow-ups. Most randomized controlled trials (RCTs) comparing percutaneous coronary intervention (PCI) with stent implantation to optimal medical therapy (OMT) in chronic coronary syndromes (CCS) patients included both hard and soft outcomes in their primary endpoint, with periprocedural myocardial infarctions (MIs) systematically allocated to the PCI arm. We meta-analyzed the above RCTs for composite hard endpoints, with and without periprocedural MIs., Evidence Acquisition: This study is registered in PROSPERO CRD42020166754 and follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Cochrane Collaboration reporting. Patients had inducible ischemia, no left main disease nor severe left ventricular dysfunction., Evidence Synthesis: Six RCTs involving 10,751 patients followed for a mean of 4.4 years were included. PCI+OMT versus OMT alone was associated with no difference in the two co-primary composite endpoints of all-cause death/MI/stroke and cardiovascular death/MI including all-MIs (IRR 0.99; 95% CI 0.90-1.08 and IRR 0.95; 95% CI 0.83-1.08 respectively). After inclusion of spontaneous rather than all-MIs (i.e., excluding periprocedural MIs), the odds showed benefit of PCI+OMT for both co-primary endpoints (IRR 0.88; 95% CI 0.80-0.97, P<0.01 and IRR 0.81; 95% CI 0.69-0.95, P=0.01 respectively) with numbers needed to treat of 42 in both cases., Conclusions: Among CCS patients with inducible myocardial ischemia without severely reduced ejection fraction or left main disease, adding PCI to OMT reduces hard composite outcomes only after exclusion of periprocedural MIs. Continued efforts to define periprocedural MIs reproducibly, to assess their prognostic relevance and to prevent them are warranted.

Myocardial infarction with non-obstructive coronary arteries (MINOCA) represents about 6-8% of patients presenting with myocardial infarction (MI), and it is associated with a significant risk of mortality, rehospitalisation, and angina burden, with high associated socioeconomic costs. It is important to note that multiple mechanisms may be responsible for MINOCA. However, to date, there are few prospective clinical trials on MINOCA and the treatment of these patients is still not defined, most likely because of the multiple underlying pathogenic mechanisms. The PROMISE trial is a randomised, multicentre, prospective, superiority, phase IV trial that will include 180 MINOCA patients randomised 1:1 to a "precision-medicine approach", consisting of a comprehensive diagnostic workup and pharmacological treatment specific for the underlying cause, versus a "standard of care" approach, consisting of routine diagnostic workup and standard medical treatment for acute coronary syndrome. The aim of this study is to evaluate if the "precision-medicine approach" will improve the angina status, evaluated using the Seattle Angina Questionnaire summary score, at 12 months (primary endpoint). Secondary endpoints include the rate of major adverse cardiovascular events at 12-month follow-up, the related primary and secondary healthcare costs, and the ability of cardiac magnetic resonance to evaluate the different mechanisms of MINOCA. Of importance, the results derived from this trial may pave the way for a new pathophysiology-driven approach with cause-target therapies personalised for the mechanisms of MINOCA (ClinicalTrials.gov: NCT05122780).

Background: Intracoronary provocation testing with acetylcholine (ACh) is crucial for the diagnosis of functional coronary alterations in patients with suspected myocardial ischaemia and non-obstructive coronary arteries., Aims: Our intention was to assess the safety and predictive value for major adverse cardiovascular and cerebrovascular events (MACCE) in patients presenting with ischaemia with non-obstructive coronary arteries (INOCA) or with myocardial infarction with non-obstructive coronary arteries (MINOCA)., Methods: We prospectively enrolled consecutive INOCA or MINOCA patients undergoing intracoronary ACh provocation testing., Results: A total of 317 patients were enrolled: 174 (54.9%) with INOCA and 143 (45.1%) with MINOCA. Of these, 185 patients (58.4%) had a positive response to the ACh test. Complications during ACh provocative testing were all mild and transient and occurred in 29 (9.1%) patients, with no difference between patients with positive or negative responses to ACh testing, nor between INOCA and MINOCA patients. A history of paroxysmal atrial fibrillation, moderate/severe diastolic dysfunction and a higher QT dispersion at baseline electrocardiogram were independent predictors of complications. MACCE occurred in 30 patients (9.5%) during a median follow-up of 22 months. The incidence of MACCE was higher among patients with a positive ACh test (24 [13.0%] vs 6 [4.5%], p=0.017), and a positive ACh test was an independent predictor of MACCE., Conclusions: ACh provocation testing is associated with a low risk of mild and transient complications, with a similar prevalence in both INOCA and MINOCA patients. Importantly, ACh provocation testing can help to identify patients at higher risk of future clinical events, suggesting a net clinical benefit derived from its use in this clinical setting.

Since optical coherence tomography (OCT) was first performed in humans two decades ago, this imaging modality has been widely adopted in research on coronary atherosclerosis and adopted clinically for the optimization of percutaneous coronary intervention. In the past 10 years, substantial advances have been made in the understanding of in vivo vascular biology using OCT. Identification by OCT of culprit plaque pathology could potentially lead to a major shift in the management of patients with acute coronary syndromes. Detection by OCT of healed coronary plaque has been important in our understanding of the mechanisms involved in plaque destabilization and healing with the rapid progression of atherosclerosis. Accurate detection by OCT of sequelae from percutaneous coronary interventions that might be missed by angiography could improve clinical outcomes. In addition, OCT has become an essential diagnostic modality for myocardial infarction with non-obstructive coronary arteries. Insight into neoatherosclerosis from OCT could improve our understanding of the mechanisms of very late stent thrombosis. The appropriate use of OCT depends on accurate interpretation and understanding of the clinical significance of OCT findings. In this Review, we summarize the state of the art in cardiac OCT and facilitate the uniform use of this modality in coronary atherosclerosis. Contributions have been made by clinicians and investigators worldwide with extensive experience in OCT, with the aim that this document will serve as a standard reference for future research and clinical application., (© 2022. Springer Nature Limited.)

Background: Acute myocardial infarction with non-obstructive coronary artery disease (MINOCA) is frequent in patients experiencing an early-onset MI, but data concerning its long-term prognosis are limited and conflicting., Methods: The Italian Genetic Study on Early-onset MI enrolled 2000 patients experiencing a first MI before the age of 45 years, and had a median follow-up of 19.9 years. The composite primary endpoint was cardiovascular (CV) death, non-fatal MI, and non-fatal stroke (MACE); the secondary endpoint was rehospitalisation for coronary revascularisation., Results: MINOCA occurred in 317 patients (15.9%) and, during the follow-up, there was no significant difference in MACE rates between them and the patients with obstructive coronary artery disease (MICAD: 27.8% vs 37.5%; adjusted hazard ratio [HR] 0.79, 95% confidence interval [CI] 0.57-1.09;p = 0.15). The CV death rate was lower in the MINOCA group (4.2% vs 8.4%, HR 0.26, 95%CI 0.08-0.86;p = 0.03), whereas the rates of non-fatal reinfarction (17.3% vs 25.4%; HR 0.76, 95%CI 0.52-1.13;p = 0.18), non-fatal ischemic stroke (9.5% vs 3.7%; HR 1.79, 95%CI 0.87-3.70;p = 0.12), and all-cause mortality (14.1% vs 20.7%, HR 0.73, 95%CI 0.43-1.25;p = 0.26) were not significantly different in the two groups. The rate of rehospitalisation for coronary revascularisation was lower among the MINOCA patients (6.7% vs 27.7%; HR 0.27, 95% CI 0.15-0.47;p < 0.001)., Conclusions: MINOCA is frequent and not benign in patients with early-onset MI. Although there is a lower likelihood of CV death,the long-term risk of MACE and overall mortality is not significantly different from that of MICAD patients., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: Contrast fractional flow reserve (cFFR) is a relatively new tool for the assessment of intermediate coronary artery stenosis and represents a reliable surrogate of FFR with the advantage of potentially simplifying functional evaluation. We aimed to compare the incidence of major adverse cardiac events (MACE) in patients undergoing functional evaluation with both FFR and cFFR based on the results of the two indexes., Method and Result: We retrospectively analyzed outcomes in 488 patients who underwent functional evaluation with FFR and cFFR. Patients were divided into four groups using the cutoff values of 0.80 for FFR and 0.85 for cFFR: -/- (n = 298), +/+ (n = 134), -/+(n = 31) and +/- (n = 25). All patients were treated according to FFR value. MACE rate was assessed in each group, including death, myocardial infarction and urgent target vessel revascularization (TVR). Mean follow-up time was 22 ± 15 months. Incidence of MACE at follow-up was 8.3% in FFR-/cFFR-, 14.0% in FFR+/cFFR+, 16.0% in FFR-/cFFR+ and 8.0% in FFR+/cFFR- without a significant difference amongst the 4 groups (p = 0.2). Nevertheless, a significant difference in the rate of TVR comparing FFR-/cFFR- (n = 17) and FFR-/cFFR+ (n = 5) was found at 24 months (5.7% vs 16.0%; p = 0.027)., Conclusion: cFFR is accurate in predicting FFR and consequently reliable in guiding coronary revascularization. In the rare case of discordance, while FFR+/cFFR- patients show a prognosis similar to FFR-/cFFR- patients, FFR-/cFFR+ patients show a prognosis similar to FFR+/cFFR+ patients., Competing Interests: Declaration of Competing Interest A.M.L. received speaking honoraria from St. Jude Medical/Abbott, Medtronic, Abiomed and from Bracco Imaging, C.T, F.B. received speaker's fees from Abbott, Medtronic, and Abiomed. The other authors have no conflicts of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Myocardial infarction with non-obstructive coronary artery (MINOCA) disease represents a heterogeneous clinical conundrum accounting for about 6% of all acute myocardial infarction (MI) cases. Initially believed to be a benign condition, is now becoming clear that MINOCA is associated with a non-negligible risk of mortality, rehospitalization, disability and angina burden at follow-up, with high socioeconomic costs. To date, there are no prospective clinical trials in this population and cannot be assumed that benefits observed in patients suffering from MI with obstructive coronary artery disease may successfully translate to this syndrome. Herein, we comment on the importance of the multimodality assessment to properly identify and treat the specific causes of MINOCA, in order to improve prognosis and the quality of life in these patients.

Background: The long-term mortality of patients with myocardial infarction and nonobstructed coronary arteries (MINOCA) remains poorly defined. This study aimed to determine the long-term mortality of patients with MINOCA and to identify potential prognostic determinants of long-term outcome., Methods: We searched PubMed, EMBASE, and Cochrane databases and reviewed cited references up to December 31, 2018 to identify studies with >6 months' follow-up data., Results: We selected 44 studies including 36,932 patients (20,052 women and 16,880 men). During a median follow-up of 25 months (interquartile range: 23-39 months), 1409 patients had died (3.8%). Overall, annual mortality rate was 2.0% (95% confidence interval [CI]: 1.5% to 2.4%), with significant heterogeneity (I 2 = 80%, P < .001). Meta-analysis of the 26 studies comparing patients with MINOCA with those with myocardial infarction and obstructive coronary artery disease showed that annual rates of long-term total mortality were 2.2% (95% CI: 1.7% to 2.7%) and 5.0% (95% CI: 4.1% to 5,9%), respectively, with a significant difference between the two groups (relative risk: 0.60, 95% CI: 0.46 to 0.78, P < .001). Meta-regression analysis demonstrated that normal ejection fraction (P ≤ .0001) and normal coronary arteries at angiography (P = .004) were inversely related to long-term mortality, whereas use of beta-blockers during follow-up (P = .010) and ST depression on the admission electrocardiogram (P = .016) were directly related with worse outcome., Conclusions: The long-term mortality after MINOCA is lower than that in patients with myocardial infarction and obstructive coronary artery disease, but it is not trivial. Reduced ejection fraction, nonobstructive coronary artery disease, use of beta-blockers during follow up and ST depression on the admission electrocardiogram are significant predictors of long-term prognosis., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Importance: Invasive physiologic indices such as fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) are used in clinical practice. Nevertheless, comparative prognostic outcomes of iFR-guided and FFR-guided treatment in patients with type 2 diabetes have not yet been fully investigated., Objective: To compare 1-year clinical outcomes of iFR-guided or FFR-guided treatment in patients with and without diabetes in the Functional Lesion Assessment of Intermediate Stenosis to Guide Revascularization (DEFINE-FLAIR) trial., Design, Setting, and Participants: The DEFINE-FLAIR trial is a multicenter, international, randomized, double-blinded trial that randomly assigned 2492 patients in a 1:1 ratio to undergo either iFR-guided or FFR-guided coronary revascularization. Patients were eligible for trial inclusion if they had intermediate coronary artery disease (40%-70% diameter stenosis) in at least 1 native coronary artery. Data were analyzed between January 2014 and December 2015., Interventions: According to the study protocol, iFR of 0.89 or less and FFR of 0.80 or less were used as criteria for revascularization. When iFR or FFR was higher than the prespecified threshold, revascularization was deferred., Main Outcomes and Measures: The primary end point was major adverse cardiac events (MACE), defined as the composite of all-cause death, nonfatal myocardial infarction, or unplanned revascularization at 1 year. The incidence of MACE was compared according to the presence of diabetes in iFR-guided and FFR-guided groups., Results: Among the total trial population (2492 patients), 758 patients (30.4%) had diabetes. Mean age of the patients was 66 years, 76% were men (1868 of 2465), and 80% of patients presented with stable angina (1983 of 2465). In the nondiabetes population (68.5%; 1707 patients), iFR guidance was associated with a significantly higher rate of deferral of revascularization than the FFR-guided group (56.5% [n = 477 of 844] vs 46.6% [n = 402 of 863]; P < .001). However, it was not different between the 2 groups in the diabetes population (42.1% [n = 161 of 382] vs 47.1% [n = 177 of 376]; P = .15). At 1 year, the diabetes population showed a significantly higher rate of MACE than the nondiabetes population (8.6% vs 5.6%; adjusted hazard ratio [HR], 1.88; 95% CI, 1.28-2.64; P < .001). However, there was no significant difference in MACE rates between iFR-guided and FFR-guided groups in both the diabetes (10.0% vs 7.2%; adjusted HR, 1.33; 95% CI, 0.78-2.25; P = .30) and nondiabetes population (4.7% vs 6.4%; HR, 0.83; 95% CI, 0.51-1.35; P = .45) (interaction P = .25)., Conclusions and Relevance: The diabetes population showed significantly higher risk of MACE than the nondiabetes population, even with the iFR-guided or FFR-guided treatment. The iFR-guided and FFR-guided treatment showed comparable risk of MACE and provided equal safety in selecting revascularization target among patients with diabetes., Trial Registration: ClinicalTrials.gov identifier: NCT02053038.

Importance: At one end of the coronary artery disease (CAD) spectrum, there are patients with multiple recurrent acute coronary syndromes (rACS), and at the other end there are those with long-standing clinical stability. Predicting the natural history of these patients is challenging because unstable plaques often heal without resulting in ACS., Objective: To assess in vivo the coronary atherosclerotic phenotype as well as the prevalence and characteristics of healed coronary plaques by optical coherence tomography (OCT) imaging in patients at the extremes of the CAD spectrum., Design, Setting, and Participants: This is an observational, single-center cohort study with prospective clinical follow-up. From a total of 823 consecutive patients enrolled in OCT Registry of the Fondazione Policlinico A. Gemelli-IRCCS, Rome, Italy, from March 2009 to February 2016, 105 patients were included in the following groups: (1) patients with rACS, defined as history of at least 3 acute myocardial infarctions (AMIs) or at least 4 ACS with at least 1 AMI; (2) patients with long-standing stable angina pectoris (ls-SAP), defined as a minimum 3-year history of stable angina; and (3) patients with a single unheralded AMI followed by a minimum 3-year period of clinical stability (sAMI). Data were analyzed from January to August 2018., Exposures: Intracoronary OCT imaging of nonculprit coronary segments., Main Outcomes and Measures: Coronary plaque features and the prevalence of healed coronary plaques in nonculprit segments as assessed by intracoronary OCT imaging., Results: Of 105 patients, 85 were men (81.0%); the median (interquartile range) age was 68 (63-75) years. Median (interquartile range) time of clinical stability was 9 (5.0-15.0) years in the ls-SAP group and 8 (4.5-14.5) years in the sAMI group. Patients in the rACS and sAMI groups showed similar prevalence of lipid-rich plaque and thin-cap fibroatheroma, which was significantly higher than in those with ls-SAP (lipid-rich plaque 80.0% [n = 24 of 30] vs 76.3% [n = 29 of 38] vs 37.8% [n = 14 of 37], respectively; P < .001; thin-cap fibroatheroma 40.0% [n = 12 of 30] vs 34.2% [n = 13 of 38] vs 8.1% [n = 3 of 37], respectively; P = .006). Spotty calcifications were more frequently observed in patients with rACS than in those with ls-SAP and sAMI (70.0% [n = 21 of 30] vs 40.5% [n = 15 of 37] vs 44.7% [n = 17 of 38], respectively; P = .04). Healed coronary plaques were rarely observed in patients with rACS, whereas their prevalence was significantly higher in patients with ls-SAP and sAMI (3.3% [n = 1 of 30] vs 29.7% [n = 11 of 37] vs 28.9% [n = 11 of 38], respectively; P = .01)., Conclusions and Relevance: Patients with rACS have a distinct atherosclerotic phenotype compared with those with ls-SAP, including higher prevalence of thin-cap fibroatheroma and lower prevalence of healed coronary plaques, suggesting that atherosclerotic profile and plaque healing may play a role in leading the natural history of patients with CAD.

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a syndrome with different causes, characterised by clinical evidence of myocardial infarction with normal or near-normal coronary arteries on angiography. Its prevalence ranges between 5% and 25% of all myocardial infarction. The prognosis is extremely variable, depending on the cause of MINOCA. The key principle in the management of this syndrome is to clarify the underlying individual mechanisms to achieve patient-specific treatments. Clinical history, electrocardiogram, cardiac enzymes, echocardiography, coronary angiography and left ventricular angiography represent the first level diagnostic investigations to identify the causes of MINOCA. Regional wall motion abnormalities at left ventricular angiography limited to a single epicardial coronary artery territory identify an 'epicardial pattern'whereas regional wall motion abnormalities extended beyond a single epicardial coronary artery territory identify a 'microvascular pattern'. The most common causes of MINOCA are represented by coronary plaque disease, coronary dissection, coronary artery spasm, coronary microvascular spasm, Takotsubo cardiomyopathy, myocarditis, coronary thromboembolism, other forms of type 2 myocardial infarction and MINOCA of uncertain aetiology. This review aims at summarising the diagnosis and management of MINOCA, according to the underlying physiopathology.

Cardioprotection refers to a strategy aimed at enhancing survival pathways in the injured yet salvageable myocardium following ischemia-reperfusion. Low-density lipoprotein receptor-related protein 1 (LRP1) is a multifunctional receptor that can be targeted following reperfusion, to induce a cardioprotective signaling through the activation of the reperfusion injury salvage kinase (RISK) pathway. The data from preclinical studies with non-selective and selective LRP1 agonists are promising, showing a large therapeutic window for intervention to reduce infarct size after ischemia-reperfusion. A pilot clinical trial with plasma derived α 1-antitrypsin (AAT), a naturally occurring LRP1 agonist, supports the translational value of LRP1 as a novel therapeutic target for cardioprotection. A phase I study with a selective LRP1 agonist has been completed showing no toxicity. These findings may open the way to early phase clinical studies with pharmacologic LRP1 activation in patients with acute myocardial infarction (AMI).

Background: The aim was to assess whether periprocedural myocardial injury (PPMI) predicts outcomes in patients undergoing transcatheter aortic valve replacement (TAVR). PPMI is a strong predictor of outcomes following coronary intervention, but its impact in the context of TAVR remains unclear. We performed a systematic review and meta-analysis to ascertain the association between PPMI and short- or long-term outcomes., Methods and Results: Electronic searches identified studies reporting PPMI following TAVR. Primary end point was 30-day all-cause mortality, with secondary end points, including 1-year all-cause mortality, neurological events, post-TAVR pacemaker implantation, and aortic regurgitation. Analyses were performed using random effects modeling and reported as summary odds ratio (OR) with 95% CI. Nine studies comprising 3442 patients (mean age 81.0±6.6 years, 51.2% female) were included. PPMI occurred in 25.5% of patients following TAVR. The pooled all-cause mortality at 30-days and 1-year was 5.2% and 18.6%, respectively. The occurrence of PPMI following TAVR was associated with significantly increased risk of both 30-day (OR, 4.23; CI, 1.95-9.19; P<0.001) and 1-year all-cause mortality (OR, 1.77; CI, 1.05-2.99; P<0.001). Similarly, PPMI was associated with post-TAVR neurological events (OR, 2.72; CI, 1.69-4.37; P<0.001) and post-TAVR permanent pacing (OR, 1.43; CI, 1.02-2.00; P=0.04) but not with a statistically significant increase in aortic regurgitation post-TAVR (OR, 1.39; CI, 0.93-2.08; P=0.11)., Conclusions: PPMI is common following TAVR and is strongly associated with 30-day and 1-year mortality. Detection of PPMI has potential to identify TAVR patients at highest risk of subsequent adverse events.

Aims: Functional alterations of epicardial coronary arteries or coronary microcirculation represent a frequent cause of myocardial infarction and non-obstructive coronary arteries (MINOCA). We aimed at assessing the prognostic value of intracoronary provocative tests in patients presenting with MINOCA and in which other causes of MINOCA have been excluded., Methods and Results: We prospectively evaluated patients with a diagnosis of MINOCA, excluding patients with aetiologies other than suspected coronary vasomotor abnormalities. Immediately after coronary angiography, an invasive provocative test using acetylcholine or ergonovine was performed. The incidence of death from any cause, cardiac death, and recurrence of acute coronary syndrome (ACS) was assessed at follow-up. We also assessed angina status using Seattle Angina Questionnaires (SAQ). We enrolled 80 consecutive patients [mean age 63.0 ± 10.7 years, 40 (50%) male]. Provocative test was positive in 37 (46.2%) patients without any complication. Among patients with a positive test, epicardial spasm was detected in 24 (64.9%) patients and microvascular spasm in 13 (35.1%) patients. After a median follow-up of 36.0 (range 12.0-60.0) months, patients with a positive test had a significantly higher occurrence of death from any cause [12 (32.4%) vs. 2 (4.7%); P = 0.002], cardiac death [7 (18.9%) vs. 0 (0.0%); P = 0.005], and readmission for ACS [10 (27.0%) vs. 3 (7.0%); P = 0.015] as well as a worse angina status as assessed by SAQ [Seattle score: 88.0 (33.0-100.0) vs. 100.0 (44.0-100.0); P = 0.001] when compared with patients with a negative test., Conclusions: We demonstrate that in patients presenting with MINOCA and suspected coronary vasomotor abnormalities, a positive provocative test for spasm is safe and identifies a high-risk subset of patients., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.)

Background: The role of culprit plaque and related atherothrombotic components on incomplete stent apposition (ISA) occurrence after primary percutaneous coronary intervention (p-PCI) is unknown., Methods and results: ST-segment elevation myocardial infarction (STEMI) patients undergoing p-PCI with an everolimus-eluting stent were prospectively investigated with optical coherence tomography (OCT) of the infarct-related artery before, after stenting and at 9 months. OCT data, aspirated thrombus and serum inflammatory biomarkers were analyzed. 114 patients with 114 lesions were evaluated. Acute ISA occurred in 82 lesions (71.9%), preferentially in larger vessels with a median area of 0.2 mm(2). The presence of thrombus before stent implantation (odds ratio (OR) 5.5, 95% confidence interval (CI) [1.1-26.9], P=0.04) and the lipid content in the target segment (OR 1.3, 95% CI [1.0-1.5], P=0.04) independently predicted acute ISA. At 9-month follow-up, ISA persisted in 46 lesions (56.1%). The volume of acute ISA significantly predicted persistent ISA (OR 1.3, 95% CI [1.1-1.5], P=0.01). Late-acquired ISA occurred in 39 lesions (34.2%) with a median area of 0.3 mm(2). Red/mixed thrombus before stent implantation (OR 3.7, 95% CI [1.0-13.3], P=0.05) and length of the underlying ruptured plaque (OR 1.7, 95% CI [1.1-2.8] P=0.02) were independently associated with late-acquired ISA., Conclusions: In STEMI patients, culprit plaque and atherothrombotic components of the infarct-related artery significantly contribute to the onset of acute and late ISA. ISA persistence at follow-up depends on the initial volume of acute ISA.

Background: The role of allergic inflammation in acute coronary syndromes (ACS) has not been clearly defined to date. Aim of this study was to assess eosinophil and basophil activation in ACS and the prognostic role of eosinophil cationic protein in ST-segment-elevation myocardial infarction., Methods and Results: In a cross-sectional study, we prospectively enrolled 51 patients undergoing percutaneous coronary intervention (60.8% patients with ACS and 39.2% with stable angina). Flow cytometry analysis assessed CD66b, CD69, and CD203c median fluorescence intensity expression. In a follow-up study, 181 patients presenting with ST-segment-elevation myocardial infarction, undergoing primary percutaneous coronary intervention, were prospectively enrolled with a follow-up of 24 months. Eosinophil activation (CD66b) was similar in patients with ACS and stable angina (6.61 [4.91-7.72] versus 6.62 [5.27-8.73], P=0.63), whereas eosinophil degranulation (CD69) and basophil activation (CD203c) were higher in ACS patients compared with stable angina patients (1.38 [1.16-1.52] versus 1.17 [1-1.31], P=0.01); 0.97 [0.89-1.11] versus 0.92 [0.87-0.95], P=0.03, respectively). Eosinophil cationic protein serum levels were significantly higher in ST-segment-elevation myocardial infarction patients with major adverse cardiac events as compared with those without (21.1 [10.37-25.65] versus 7.83 [3.37-12.8] μg/L, P=0.01) and in patients with thrombus score >3 compared with those with thrombus score ≤3 (15.0 [9.8-24.7] versus 5.2 [3.5-22.9] μg/L, P=0.006). Eosinophil cationic protein serum levels predicted major adverse cardiac events during follow-up (odds ratio =1.041, 95% confidence interval 1.012-1.071, P=0.005). C-reactive protein serum levels showed a borderline statistical significance (odds ratio =0.904, 95% confidence interval 0.806-1.014, P=0.085)., Conclusions: These findings are the first demonstration of in vivo eosinophil degranulation and basophil activation during ACS and of the prognostic role of eosinophil cationic protein in ST-segment-elevation myocardial infarction., (© 2015 American Heart Association, Inc.)

Objective: To analyze the immediate and long-term outcomes of transradial (TR) percutaneous coronary intervention (PCI) to unprotected left main stem (ULMS) bifurcation and to assess the main aspects affecting access-site choice in this specific PCI setting., Background: TR-PCI to the ULMS is feasible, but data specifically comparing TR and transfemoral (TF) approaches in ULMS-bifurcation PCI are limited., Methods: We set up a two-center (Rome, Italy and Oxford, United Kingdom) retrospective registry aimed at comparing the immediate and 1-year outcomes of consecutive patients who underwent ULMS-bifurcation PCI with drug-eluting stent implantation from 2005 to 2013 using the TF or TR approach. Clinical endpoints were: total mortality; major adverse cardiac and cerebrovascular event (MACCE) rate; and net adverse clinical event (NACE) rate., Results: A total of 467 patients undergoing ULMS-bifurcation PCI were enrolled (221 TF and 244 TR). TR approach was increasingly adopted over time for both simple and complex procedures. No significant differences were observed between the TR and TF groups in terms of 1-year mortality (10.7% vs 9.8%; P=.79) and MACCE (18.2% vs 15.2%; P=.44). TR patients, as compared with TF, had significantly fewer access-site complications (2.0% vs 6.3% in TF; P=.02), resulting in a significant reduction of NACE rate (6.9% vs 15.7;%; P=.01)., Conclusion: In patients undergoing ULMS-bifurcation PCI, the selection of TR instead of TF approach is associated with similar early and long-term ischemic complications and with a significant reduction of access-site complications, resulting in lower NACE rate.

Background: Gonadal function is thought to be involved in existing atherosclerotic plaques stabilization and might affect reperfusion after primary percutaneous coronary intervention (pPCI). We aimed to compare the prevalence of hypotestosteromenia between ST-elevation myocardial infarction (STEMI) and stable angina (SA) patients and between patients with and without microvascular obstruction (MVO)., Design: Cross-sectional observational study., Methods: Males with STEMI (n = 70, age 57.1 ± 7.8 years) or with stable angina (n=30, age 59.9 ± 8.4 years) were enrolled. Angiographic MVO (angio-MVO) was defined as final TIMI flow 2 or final TIMI flow 3 with MBG ≤ 2 while electrocardiographic MVO (ECG-MVO) as a ST-segment resolution <70% at 90 minutes post-pPCI. Variables associated with STEMI and MVO were assessed among clinical, angiographic and laboratory data including testosterone (T) and insulin-like factor 3 (INSL-3), a marker of Leydig cells function. Hypotestosteronemia was defined as T<2.50 ng/ml with INSL-3<305.5 pg/ml., Results: Hypotestosteronemia was detected in 32 (45.7%) STEMI patients and in 4 (13.3%) SA patients (p=0.003). STEMI patients presenting with angio-MVO were more frequently hypotestosteronemic as compared with those without (60.9% vs 38.3%, p=0.043). Hypotestosteronemia prevalence was higher among STEMI patients presenting with ECG-MVO as compared with those without (69.0% vs 31.7%, p=0.003). At multivariate analysis hypotestosteronemia independently predicted both angio-MVO (OR=4.47, 95% CI 1.30-15.36, p=0.018) and ECG-MVO (OR=7.56, 95% CI 2.20-25.99, p=0.001)., Conclusions: Our study shows higher prevelence of hypotestosteronemia among STEMI patients as compared with SA patients and among STEMI patients with MVO as compared with those without, thus suggesting a possible role of T deficiency in coronary instability and MVO pathogenesis., (© The European Society of Cardiology 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.)

Plaque rupture (PR) and superimposed thrombosis have been shown as the most frequent underlying substrate in acute coronary syndromes (ACS). Coronary angiography is a luminogram not able to define in vivo features of the culprit plaques. The aim of the study was to use optical coherence tomography (OCT) to investigate the pathology underlying complex (CL) and non-complex angiographic lesions (NCL). We retrospectively enrolled 107 ACS patients admitted to our institution; 83 with non-ST elevation ACS (NSTE-ACS) and 24 with ST-elevation myocardial infarction. Coronary angiography was performed and culprit lesions were classified according to Ambrose criteria into NCL (n = 47) and CL (n = 60). OCT imaging was then performed to better identify plaque morphology; either PR or intact fibrous cap, the presence of superimposed thrombosis, lipid rich plaque, and thin cap fibroatheroma (TCFA). OCT analysis showed that 58 lesions (54.2%) were classified as PR and 48 lesions (44.9%) were associated with thrombi. Lipid rich plaques were identified in 62 lesions (57.9%). PR, intracoronary thrombi, lipid rich plaques and TCFA were more frequent in CL compared with NCL (71.7 vs 31.9%, 63.3 vs 21.3%, 71.7 vs 40.4% and 46.7 vs 21.3% respectively), but PR with superimposed thrombus may be also detected in NCL. OCT demonstrates PR and thrombosis in the majority of ACS patients presenting with CL. However, one-third of NCL show PR by OCT, suggesting that additional intracoronary imaging by OCT may better identify the underlying mechanism of coronary instability than coronary angiography alone.

Objectives: The aim of this study was to evaluate the pathophysiological features and response to primary percutaneous coronary intervention (PCI) of nonruptured/eroded plaque versus ruptured plaque as a cause of ST-segment elevation myocardial infarction (STEMI)., Background: Autopsy series identified nonruptured/eroded plaque and ruptured plaque as the principal pathological substrates underlying coronary thrombosis in STEMI. The real incidence of different plaque morphologies, associated biological factors, superimposed thrombus, and their interaction with primary PCI remain largely unknown., Methods: In a prospective study, 140 patients with STEMI underwent optical coherence tomography of the infarct-related artery (IRA) before PCI, after everolimus-eluting stent implantation and at 9-month follow-up. Histopathology and immunohistochemistry of thrombus aspirates and serum biomarkers were assessed at baseline., Results: Culprit plaque morphology was adjudicated in 97 patients: 32 plaques (33.0%) with an intact fibrous cap (IFC), 63 (64.9%) plaques with a ruptured fibrous cap (RFC), and 2 (2.1%) spontaneous dissections. Patients with an IFC and RFC had similar clinical characteristics, and serum inflammatory and platelets biomarkers. An IFC presented more frequently with a patent IRA (56.2% vs. 34.9%; p = 0.047), and had fewer lipid areas (lipid-rich areas: 75.0% vs. 100.0%; p < 0.001) and less residual thrombus before stenting (white thrombus: 0.41 mm(3) vs. 1.52 mm(3); p = 0.001; red thrombus: 0 mm(3) vs. 0.29 mm(3); p = 0.001) with a lower peak of creatine kinase-myocardial band (66.6 IU/l vs. 149.8 IU/l; p = 0.025). At the 9-month optical coherence tomography, IFC and RFC had similar high rates of stent strut coverage (92.5% vs. 91.2%; p = 0.15) and similar percentage of volume obstruction (12.6% vs. 10.2%; p = 0.27). No significant differences in clinical outcomes were observed up to 2 years., Conclusions: In the present study, an IFC was observed at the culprit lesion site of one-third of STEMIs. IFC, compared with RFC, was associated with higher rates of patent IRA at first angiography, fewer lipid areas, and residual endoluminal thrombus. However, no difference in vascular response to everolimus-eluting stent was observed. (Optical Coherence Tomography Assessment of Gender Diversity in Primary Angioplasty [OCTAVIA]; NCT01377207)., (Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Myocardial infarction (MI) with no obstructive coronary atherosclerosis (MINOCA) is a syndrome with different causes. Its prevalence ranges between 5 and 25% of all MIs. The prognosis is extremely variable, depending on the causes of MINOCA. Clinical history, echocardiography, coronary angiography, and left ventriculography represent the first-level diagnostic investigations. Nevertheless, additional tests are required in order to establish its specific cause, thus allowing an appropriate risk stratification and treatment. We review pathogenesis, diagnosis, prognosis, and therapy of MINOCA and propose an algorithm for its management., (© Crown copyright 2014.)

We describe a case of very late stent thrombosis with documentation of highly calcific restenosis at optical coherence tomography without clear signs of stent malapposition, neoatherosclerosis disruption, or vascular toxicity to stent polymer. To the best of our knowledge, this is one of the first reports dealing with highly calcific restenosis as a potential background to very late stent thrombosis.

Objectives: This study sought to assess in vivo sex differences in the pathophysiology of ST-segment elevation myocardial infarction (STEMI) and vascular response to primary percutaneous coronary intervention (PCI)., Background: There is no consensus on whether differences in the pathophysiology of STEMI and response to primary PCI between women and men reflect biological factors as opposed to differences in age., Methods: In this prospective, multicenter study, 140 age-matched men and women with STEMI undergoing primary PCI with everolimus-eluting stent were investigated with intravascular optical coherence tomography, histopathology-immunohistochemistry of thrombus aspirates, and serum biomarkers. Primary endpoints were the percentages of culprit plaque rupture at baseline and everolimus-eluting stent strut coverage at 9-month follow-up as determined by optical coherence tomography., Results: Men and women had similar rates of plaque rupture (50.0% vs. 48.4%; risk ratio [RR]: 1.03; 95% confidence interval [CI]: 0.73 to 1.47; p = 0.56). Nonruptured/eroded plaques comprised 25% of all cases (p = 0.86 in men vs. women). There were no sex differences in composition of aspirated thrombus and immune and inflammatory serum biomarkers. At 9 months, women had similar strut coverage (90.9% vs. 92.5%; difference in medians: RR: 0.2%; 95% CI: -0.4% to 1.3%; p = 0.89) and amount of in-stent neointimal obstruction (10.3% vs. 10.6%; p = 0.76) as men did. There were no sex differences in clinical outcome either at 30-day or 1-year follow-up., Conclusions: In patients presenting with STEMI undergoing primary PCI, no differences in culprit plaque morphology and factors associated with coronary thrombosis were observed between age-matched men and women. Women also showed similar vascular healing response to everolimus-eluting stents as men did. (Optical Coherence Tomography Assessment of Gender Diversity In Primary Angioplasty: The OCTAVIA Trial [OCTAVIA]; NCT01377207)., (Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Our study aimed to elucidate mechanisms underlying discordance between fractional flow reserve (FFR) and hyperemic stenosis resistance (hSR) in some patient subsets. To do this, we enrolled 30 consecutive patients with stable angina or non-ST elevation myocardial infarction (non-STEMI) and with a nonculprit intermediate coronary lesion (40% to 70%) by coronary angiography. We measured aortic pressure, flow velocity, and pressure distal to lesion simultaneously at basal level and during adenosine-induced (fixed intracoronary dose of 120 μg) hyperemia using a dual-sensor-equipped guidewire. Microvascular resistance (MR; pressure distal to lesion/flow velocity, mm Hg/cm/s) and variation (Δ) in MR levels were calculated both at baseline and after hyperemia, whereas FFR (cutoff <0.80) and hSR [(aortic pressure - pressure distal to lesion)/flow velocity, cutoff >0.80 mm Hg/cm/s] were assessed after intracoronary adenosine. Twenty-three patients (76.7%) showed concordance and 7 patients (23.3%) showed discordance between FFR and hSR (all cases with FFR >0.80 and hSR >0.80). Discordant patients presented more frequently with non-STEMI (85.7% vs 39.1%, p = 0.04), significantly higher C-reactive protein serum levels (median [interquartile range] 5.9 [5.1 to 6.8] vs 4.9 [3.7 to 6.2] mg/L, p = 0.007), and lower ΔMR (p = 0.03) values compared with concordant patients. In conclusion, patients with non-STEMI and those with increased C-reactive protein levels show a lower reduction in MR after intracoronary adenosine-induced hyperemia, leading to FFR underestimation., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Guidelines report that the optimal treatment for ST-elevation myocardial infarction (STEMI) is a primary percutaneous coronary intervention (PPCI) when performed timely by trained operators. Yet, the reopening of the infarct-related artery (IRA) is not always followed by myocardial reperfusion. This phenomenon is most commonly called "no-reflow", is caused by microvascular obstruction (MVO) and is associated to a worse outcome. Electrocardiogram (ECG) is crucial for the diagnosis of STEMI, but is also useful for the assessment of MVO. In this review we summarize ECG-derived parameters associated to MVO and their prognostic relevance., (© 2013.)

Objectives: To assess the predictive value of C-reactive protein (CRP) on periprocedural myocardial injury (PMI), evaluated by creatine kinase-myocardial band isoform (CK-MB) elevation in patients undergoing percutaneous coronary intervention (PCI) with drug-eluting stent (DES) implantation for the treatment of coronary bifurcation lesions is actually unknown., Background: Systemic inflammation as assessed by CRP has been associated with averse events after DES implantation. After PCI, the occurrence of PMI is common and has also been associated with worse outcomes. Finally, bifurcations are frequently encountered anatomically complex lesions which the treatment is associated with higher complication rate compared with simple lesions., Methods: A total of 96 patients (66 ± 10 years, 70 men) from the Coronary bifurcations: Application of the Crushing Technique Using Sirolimus-eluting stents (CACTUS) trial who had baseline CRP dosage and both baseline and postprocedural CK-MB measurement were included., Results: A complex bifurcation strategy was implemented in 53 (55%) patients, and angiographic success was achieved in all but two (2%) patients. Periprocedural myocardial necrosis (increase of CK-MB between one and three times the upper limit of normal [ULN]) was observed in 12 (13%) patients, and four (4%) patients had PCI-related myocardial infarction (increase of CK-MB more than three times ULN). Notably, progressively higher CRP levels were observed in patients with different increase in CK-MB (P = 0.041). Moreover, CRP >1 mg/L significantly predicted CK-MB rise (odds ratio 5.6, 95% confidence interval 1.5-4.3, P = 0.011)., Conclusion: In the setting of true coronary bifurcations treated by DES, baseline CRP levels were significantly associated with both the incidence and the extent of PMI., (Copyright © 2013 Wiley Periodicals, Inc.)

Background: Pre-infarction angina (PIA) has been shown to reduce the microvascular obstruction (MVO) rate in patients with ST-segment elevation myocardial infarction (STEMI). We sought to evaluate the potential modulator role of cardiovascular risk factors (CRFs) on this protective effect., Methods and Results: Two hundred patients with STEMI were enrolled. PIA was defined as typical chest pain within the 48 h preceding STEMI onset. Angiographic MVO was defined as TIMI flow grade <2 or TIMI flow 3 with myocardial blush grade <2; electrocardiographic (ECG) MVO was defined as ST-segment elevation resolution <70%. Common CRFs were collected. In the absence of hypertension, both angiographic and ECG MVO rates were lower in patients with PIA as compared with those without, whereas, in the presence of hypertension, they were similar in both study groups (P for interaction=0.01 and P=0.014, respectively). Among nonsmokers, angiographic and ECG MVO rates were lower in patients with PIA as compared with those without, whereas within smokers, they were similar in both study groups (P for interaction=0.037 and P=0.037, respectively). In the absence of dyslipidemia, the angiographic and ECG MVO rates were lower in patients with PIA as compared with those without, whereas within dyslipidemic patients, they were similar in both study groups (P for interaction=0.012 and P=0.04, respectively)., Conclusions: The protective effect of PIA on MVO is blunted by CRFs.

Myocardial infarction with normal coronary arteries (MINCA) can be observed in a relevant subset of patients with MI. It can be considered a syndrome, since it includes several clinical entities with specific pathogenetic mechanisms. Its prevalence is extremely variable, accounting for 5-25% of all acute myocardial infarctions. MINCA may arise from epicardial, microvascular, or myocardial localizations. Clinical history, echocardiography, coronary angiography and left ventriculography represent the first diagnostic step; however, additional tests are often required to confirm the diagnosis. The prognosis is extremely variable, depending on the causes of MINCA. Therefore, the identification of the correct etiology of MINCA is crucial to stratify patients appropriately and, hence, select the best treatment approach. In this review article, the pathogenesis, diagnosis, prognosis and therapy of MINCA are discussed, highlighting that coronary angiography alone is not sufficient for the complete understanding of the pathogenic mechanisms.

Background: Persistent oxidative stress may play a key role in microvascular obstruction (MVO). We aimed at assessing the role of platelet gp91phox (NOX2), the catalytic subunit of NADPH oxidase in MVO., Methods: We enrolled 40 patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention within 12 h from symptoms onset, either with angiographic MVO (n=20) or good angiographic myocardial reperfusion (MR) (n=20). Angiographic MVO was defined as a final thrombolysis in myocardial infarction (TIMI) flow ≤2 or TIMI flow of 3 with myocardial blush grade <2. NOX2 and isoprostanes (8-iso-PGF2α) levels, as assessed by enzyme-linked immunoadsorbent assay (ELISA) or by an enzyme immunoassays, respectively, were measured on admission, at 24 h and pre-discharge., Results: NOX2 levels increased from baseline to pre-discharge in patients with angiographic MVO (20.25 (15-24.75) pg/ml vs 25.50 (17-29.25) pg/ml, p=0.02), but not in MR patients (p=0.45), with a significant interaction between baseline and pre-discharge levels among the two groups (p=0.04). The levels of 8-iso-PGF2α showed a trend to increase from baseline to pre-discharge in angiographic MVO patients (295 (183.50-389.25) pmol/l vs 322 (206-370) pmol/l, p=0.06), but not in patients with MR (p=0.56), with a trend for interaction between baseline and pre-discharge levels among the two groups (p=0.09)., Conclusion: Patients with MVO, but not those with myocardial reperfusion, have a sustained increase of NOX2 and 8-iso-PGF2α. Therapies targeting NOX2 or high dosage antioxidants should be tested for MVO prevention and treatment.

Endothelial progenitor cells (EPCs) are released from the bone marrow during cardiac ischemic events, potentially influencing vascular and myocardial repair. We assessed the clinical and angiographic correlates of EPC mobilization at the time of primary percutaneous coronary intervention in 78 patients with ST elevation myocardial infarction and the impact of both baseline and follow-up EPC levels on left ventricular (LV) remodeling. Blood samples were drawn from the aorta and the culprit coronary artery for cytofluorimetric EPC detection (CD34+CD45dimKDR+ cells, in percentage of cytofluorimetric counts). Area at risk was assessed by Bypass Angioplasty Revascularization Investigation myocardial jeopardy index, thrombotic burden as thrombus score and microvascular obstruction (MVO) as a combination of ST segment resolution and myocardial blush grade. Echocardiographic evaluation of LV remodeling was performed at 1-year follow-up in 54 patients, whereas peripheral EPC levels were reassessed in 40 patients. EPC levels during primary percutaneous coronary intervention were significantly higher in intracoronary than in aortic blood (0.043% vs 0.0006%, p <0.001). Both intracoronary and aortic EPC were related to area at risk extent, to intracoronary thrombus score (p <0.001), and inversely to MVO (p = 0.001). Peripheral EPC levels at 1-year follow-up were lower in patients with LV remodeling than in those without (0.001% [0.001 to 0.002] vs 0.003% [0.002 to 0.010]; p = 0.01) and independently predicted absence of remodeling at multivariate analysis. In conclusion, a rapid intracoronary EPC recruitment takes place in the early phases of ST elevation myocardial infarction, possibly reflecting an attempted reparative response. The extent of this mobilization seems to be correlated to the area at risk and to the amount of MVO. Persistently low levels of EPC are associated to LV remodeling., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Multiple plaque instability has been reported in about one-third of patients with ST elevation acute myocardial infarction (STEMI) and could be responsible for early recurrent instability after STEMI. Optical coherence tomography (OCT) is a high-resolution imaging technique that may help in detection and characterization of unstable coronary plaques. We present a case of multiple coronary instability in a patient with anterior STEMI where OCT has tailored an optimal diagnosis and treatment.