Coronary Microvascular Dysfunction: A Guide for Clinicians.

Dysfunction of the coronary microvasculature has become increasingly recognized as an important mechanism of myocardial ischemia in patients without obstructive coronary artery disease. The causes and management of coronary microvascular dysfunction remain poorly understood and is still largely based on extrapolation of epicardial coronary artery disease data. Quantification of myocardial blood flow and flow reserve have improved diagnosis, though important questions remain In this review, we explain current understanding of the spectrum of pathophysiology of coronary microvascular dysfunction, summarize current diagnostic techniques to assess for coronary microvascular dysfunction, and appraise the limited data on management options specifically for patients with coronary microvascular dysfunction.

An update on the mechanisms of Takotsubo syndrome: "At the end an acute coronary syndrome".

Takotsubo syndrome (TTS) is an acute reversible form of myocardial dysfunction, often preceded by a physical or emotional stressful event, that acts as a trigger. Despite, recent advances in the comprehension of the mechanisms leading to TTS, its pathophysiology is far from being completely understood. However, several studies seem to suggest that an acute coronary microvascular dysfunction may represent a crucial pathogenic mechanism involved in TTS occurrence. In this article, we aim to review the complex pathophysiology of TTS and the possible different mechanisms underlying this clinical condition, focusing on the role of coronary microvascular dysfunction and the remaining knowledge's gaps in the field.

Inflammation and acute cardiotoxicity in adult hematological patients treated with CAR-T cells: results from a pilot proof-of-concept study.

AIMS: Chimeric Antigen Receptor-T (CAR-T) cell infusion is a rapidly evolving antitumor therapy; however, cardiovascular (CV) complications, likely associated with cytokine release syndrome (CRS) and systemic inflammation, have been reported to occur. The CARdio-Tox study aimed at elucidating incidence and determinants of cardiotoxicity related to CAR-T cell therapy. METHODS: Patients with blood malignancies candidate to CAR-T cells were prospectively evaluated by echocardiography at baseline and 7 and 30 days after infusion. The study endpoints were i) incidence of cancer therapy-related cardiac dysfunction (CTRCD), CTRCD were also balanced for any grade CRS, but CTRCD occurred of Cardiology Guidelines on Cardio-Oncology (decrements of left ventricular ejection fraction (LVEF) or global longitudinal strain (GLS) and/or elevations of cardiac biomarkers (high sensitivity troponin I, natriuretic peptides) and ii), correlations of echocardiographic metrics with inflammatory biomarkers. RESULTS: Incidence of CTRCD was high at 7 days (59,3%), particularly in subjects with CRS. The integrated definition of CTRCD allowed the identification of the majority of cases (50%). Moreover, early LVEF and GLS decrements were inversely correlated with fibrinogen and interleukin-2 receptor levels (p always ≤ 0.01). CONCLUSIONS: There is a high incidence of early CTRCD in patients treated with CAR-T cells, and a link between CTRCD and inflammation can be demonstrated. Dedicated patient monitoring protocols are advised.

Predicting the response to acetylcholine in ischemia or infarction with non-obstructive coronary arteries: The ABCD score.

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.

Coronary Spasm Testing with Acetylcholine: A Powerful Tool for a Personalized Therapy of Coronary Vasomotor Disorders.

Coronary vasomotor disorders (CVD) are characterized by transient hypercontraction of coronary vascular smooth muscle cells, leading to hypercontraction of epicardial and/or microvascular coronary circulation. CVDs play a relevant role in the pathogenesis of ischemia, angina and myocardial infarction with non-obstructive coronary arteries. Invasive provocative testing with intracoronary Acetylcholine (ACh) administration is the gold standard tool for addressing CVD, providing relevant therapeutic and prognostic implications. However, safety concerns preclude the widespread incorporation of the ACh test into clinical practice. The purpose of this review is to shed light on the pathophysiology underlying CVD and on the clinical role of the ACh test, focusing on safety profile and prognostic implications. We will also discuss contemporary evidence on the management of CVD and the role of the ACh test in driving a personalized approach of patients with CVD.

Vaccines and Myocardial Injury in Patients Hospitalized for COVID-19 Infection: the CardioCOVID-Gemelli Study.

BACKGROUND: Myocardial injury is prevalent among patients hospitalized for COVID-19. However, the role of COVID-19 vaccines in modifying the risk of myocardial injury is unknown. OBJECTIVES: To assess the role of vaccines in modifying the risk of myocardial injury in COVID-19. METHODS: We enrolled COVID-19 patients admitted from March 2021 to February 2022 with known vaccination status and ≥1 assessment of hs-cTnI within 30 days from the admission. The primary endpoint was the occurrence of myocardial injury (hs-cTnI levels >99th percentile upper reference limit). RESULTS: 1019 patients were included (mean age 67.7±14.8 years, 60.8% male, 34.5% vaccinated against COVID-19). Myocardial injury occurred in 145 (14.2%) patients. At multivariate logistic regression analysis, advanced age, chronic kidney disease and hypertension, but not vaccination status, were independent predictors of myocardial injury. In the analysis according to age tertiles distribution, myocardial injury occurred more frequently in the III tertile (≥76 years) compared to other tertiles (I tertile:≤60 years;II tertile:61-75 years) (p<0.001). Moreover, in the III tertile, vaccination was protective against myocardial injury (OR 0.57, CI 95% 0.34-0.94; p=0.03), while a previous history of coronary artery disease was an independent positive predictor. In contrast, in the I tertile, chronic kidney disease (OR 6.94, 95% CI 1.31-36.79, p=0.02) and vaccination (OR 4.44, 95% CI 1.28-15.34, p=0.02) were independent positive predictors of myocardial injury. CONCLUSIONS: In patients ≥76 years, COVID-19 vaccines were protective for the occurrence of myocardial injury, while in patients ≤60 years, myocardial injury was associated with previous COVID-19 vaccination. Further studies are warranted to clarify the underlying mechanisms.

Exposome in ischaemic heart disease: beyond traditional risk factors.

Ischaemic heart disease represents the leading cause of morbidity and mortality, typically induced by the detrimental effects of risk factors on the cardiovascular system. Although preventive interventions tackling conventional risk factors have helped to reduce the incidence of ischaemic heart disease, it remains a major cause of death worldwide. Thus, attention is now shifting to non-traditional risk factors in the built, natural, and social environments that collectively contribute substantially to the disease burden and perpetuate residual risk. Of importance, these complex factors interact non-linearly and in unpredictable ways to often enhance the detrimental effects attributable to a single or collection of these factors. For this reason, a new paradigm called the 'exposome' has recently been introduced by epidemiologists in order to define the totality of exposure to these new risk factors. The purpose of this review is to outline how these emerging risk factors may interact and contribute to the occurrence of ischaemic heart disease, with a particular attention on the impact of long-term exposure to different environmental pollutants, socioeconomic and psychological factors, along with infectious diseases such as influenza and COVID-19. Moreover, potential mitigation strategies for both individuals and communities will be discussed.

Coronary microvascular obstruction and dysfunction in patients with acute myocardial infarction.

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.

Short-term air pollution exposure and mechanisms of plaque instability in acute coronary syndromes: An optical coherence tomography study.

BACKGROUND AND AIMS: Air pollution is emerging as an important risk factor for acute coronary syndrome (ACS). In this study, we investigated the association between short-term air pollution exposure and mechanisms of coronary plaque instability evaluated by optical coherence tomography (OCT) imaging in ACS patients. METHODS: Patients with ACS undergoing OCT imaging were retrospectively selected. Mechanism of culprit lesion instability was classified as plaque rupture (PR) or intact fibrous cap (IFC) by OCT. Based on each case's home address, the mean daily exposures to several pollutants, including particulate matter 2.5 (PM2.5), on the same day of ACS and in the immediate days (up to 6 days) prior to the index ACS, were collected. RESULTS: 139 ACS patients were included [69 (49.6%) had PR and 70 (50.4%) IFC]. Patients with PR, compared to those with IFC, had higher PM2.5 exposure levels on the same day of ACS, without differences in the immediate 6 days before index ACS. At multivariate analysis, PM2.5 exposure on the same day of ACS was the only independent predictor of PR [OR = 1.912 per SD (8.6 µg/m3), CI95 % (1.087-3.364), p = 0.025]. Patients with PR presented a steady increase in PM2.5 daily exposure levels in the days preceding the occurrence of ACS, with a peak the day of ACS (p for trend = 0.042) CONCLUSIONS: This study demonstrates for the first time that a higher short-term PM2.5 exposure, on the same day of ACS, is associated with an increased risk of PR as a pathobiological mechanism of coronary plaque instability.

Pathogenic pathways and therapeutic targets of inflammation in heart diseases: A focus on Interleukin-1.

BACKGROUND: An exuberant and dysregulated inflammatory response contributes to the development and progression of cardiovascular diseases (CVDs). METHODS: This narrative review includes original articles and reviews published over the past 20 years and found through PubMed. The following search terms (or combination of terms) were considered: "acute pericarditis," "recurrent pericarditis," "myocarditis," "cardiac sarcoidosis," "atherosclerosis," "acute myocardial infarction," "inflammation," "NLRP3 inflammasome," "Interleukin-1" and "treatment." RESULTS: Recent evidence supports the role of inflammation across a wide spectrum of CVDs including myocarditis, pericarditis, inflammatory cardiomyopathies (i.e. cardiac sarcoidosis) as well as atherosclerotic CVD and heart failure. Interleukins (ILs) are the signalling mediators of the inflammatory response. The NACHT, leucine-rich repeat and pyrin-domain containing protein 3 (NLRP3) inflammasome play a key role in producing IL-1ß, the prototypical pro-inflammatory cytokine involved in CVDs. Other pro-inflammatory cytokines (e.g. tumour necrosis factor) have been implicated in cardiac sarcoidosis. As a proof of this, IL-1 blockade has been proven efficacious in pericarditis and chronic coronary syndrome. CONCLUSION: Tailored strategies aiming at quenching the inflammatory response have emerged as promising to treat CVDs. In this review article, we summarize recent evidence regarding the role of inflammation across a broad spectrum of CVDs. We also review novel evidence regarding targeted therapeutic strategies.

Coronary physiology thresholds associated with microvascular obstruction in myocardial infarction.

OBJECTIVES: To ascertain whether invasive assessment of coronary physiology soon after recanalisation of the culprit artery by primary percutaneous coronary intervention is associated with the development of microvascular obstruction by cardiac magnetic resonance in patients with ST-segment elevation myocardial infarction (STEMI). METHODS: Between November 2020 and December 2021, 102 consecutive patients were prospectively enrolled in five tertiary centres in Italy. Coronary flow reserve (CFR) and index of microvascular resistance (IMR) were measured in the culprit vessel soon after successful primary percutaneous coronary intervention. Optimal cut-off points of IMR and CFR to predict the presence of microvascular obstruction were estimated, stratifying the population accordingly in four groups. A comparison with previously proposed stratification models was carried out. RESULTS: IMR>31 units and CFR≤1.25 yielded the best accuracy. Patients with IMR>31 and CFR≤1.25 exhibited higher microvascular obstruction prevalence (83% vs 38%, p<0.001) and lower left ventricular ejection fraction (45±9% vs 52±9%, p=0.043) compared with those with IMR≤31 and CFR>1.25, and lower left ventricular ejection fraction compared with patients with CFR≤1.25 and IMR≤31 (45±9% vs 54±7%, p=0.025). Infarct size and area at risk were larger in the former, compared with other groups. CONCLUSIONS: IMR and CFR are associated with the presence of microvascular obstruction in STEMI. Patients with an IMR>31 units and a CFR≤1.25 have higher prevalence of microvascular obstruction, lower left ventricular ejection fraction, larger infarct size and area at risk. TRIAL REGISTRATION NUMBER: NCT04677257.

Prognostic value of combined fractional flow reserve and pressure-bounded coronary flow reserve: outcomes in FFR and Pb-CFR assessment.

BACKGROUND: Coronary flow reserve (CFR) has an emerging role to predict outcome in patients with and without flow-limiting stenoses. However, the role of its surrogate pressure bounded-CFR (Pb-CFR) is controversial. We investigated the usefulness of combined use of fractional flow reserve (FFR) and Pb-CFR to predict outcomes. METHODS: This is a sub-study of the PROPHET-FFR Trial, including patients with chronic coronary syndrome and functionally tested coronary lesions. Patients were divided into four groups based on positive or negative FFR (cut-off 0.80) and preserved (lower boundary ≥2) or reduced (upper boundary <2) Pb-CFR: Group1 FFR≤0.80/ Pb-CFR <2; Group 2 FFR≤0.80/Pb-CFR≥2; Group 3 FFR >0.80/Pb-CFR<2; Group 4 FFR>0.80/Pb-CFR≥2. Lesions with positive FFR were treated with PCI. Primary endpoint was the rate of major adverse cardiac events (MACEs), defined as a composite of death from any cause, myocardial infarction, target vessel revascularization, unplanned cardiac hospitalization at 36-months. RESULTS: A total of 609 patients and 816 lesions were available for the analysis. At Kaplan-Meier analysis MACEs rate was significantly different between groups (36.7% Group 1, 27.4% Group 2, 19.2% Group 3, 22.6% Group 4, P=0.019) and more prevalent in groups with FFR≤0.80 irrespective of Pb-CFR. In case of discrepancy, no difference in MACEs were observed between groups stratified by Pb-CFR. FFR≤0.80 was associated with an increased MACEs rate (30.2% vs. 21.5%, P<0.01) while Pb-CFR<2 was not (24.5% vs. 24.2% Pb-CFR≥2 P=0.67). CONCLUSIONS: FFR confirms its ability to predict outcomes in patients with intermediate coronary stenoses. Pb-CFR does not add any relevant prognostic information.

Management of high and intermediate-high risk pulmonary embolism: A position paper of the Interventional Cardiology Working Group of the Italian Society of Cardiology.

Pulmonary embolism (PE) is a potentially life-threatening condition that remains a major global health concern. Noteworthy, patients with high- and intermediate-high-risk PE pose unique challenges because they often display clinical and hemodynamic instability, thus requiring rapid intervention to mitigate the risk of clinical deterioration and death. Importantly, recovery from PE is associated with long-term complications such as recurrences, bleeding with oral anticoagulant treatment, pulmonary hypertension, and psychological distress. Several novel strategies to improve risk factor characterization and management of patients with PE have recently been introduced. Accordingly, this position paper of the Working Group of Interventional Cardiology of the Italian Society of Cardiology deals with the landscape of high- and intermediate-high risk PE, with a focus on bridging the gap between the evolving standards of care and the current clinical practice. Specifically, the growing importance of catheter-directed therapies as part of the therapeutic armamentarium is highlighted. These interventions have been shown to be effective strategies in unstable patients since they offer, as compared with thrombolysis, faster and more effective restoration of hemodynamic stability with a consistent reduction in the risk of bleeding. Evolving standards of care underscore the need for continuous re-assessment of patient risk stratification. To this end, a multidisciplinary approach is paramount in refining selection criteria to deliver the most effective treatment to patients with unstable hemodynamics. In conclusion, the current management of unstable patients with PE should prioritize tailored treatment in a patient-oriented approach in which transcatheter therapies play a central role.

Pathophysiology of coronary microvascular dysfunction.

The term "coronary microvascular dysfunction" (CMD) encompasses several pathogenetic mechanisms resulting in functional and/or structural changes in the coronary microcirculation. CMD often determines angina and myocardial ischemia in a broad spectrum of cardiovascular diseases, including patients with ischemia with non-obstructive coronary arteries or ischemia with obstructive coronary artery disease, infarction with non-obstructive coronary arteries, cardiomyopathies, the Takotsubo syndrome and heart failure, especially heart failure with preserved ejection fraction. In this article, we provide updated evidence regarding the pathophysiological mechanisms underlying CMD across the different cardiovascular diseases, aiming to pave the way for further research and the development of novel strategies for a precision medicine approach.

[Myocardial infarction with non-obstructive coronary artery disease: diagnostic work-up in the catheterization laboratory]. / L'infarto miocardico in assenza di coronaropatia ostruttiva: work-up diagnostico nel laboratorio di Emodinamica.

Myocardial infarction with non-obstructive coronary artery disease (MINOCA) is a heterogeneous clinical condition affecting 5% to 8% of patients presenting with acute myocardial infarction. Initially it was considered a favorable clinical diagnosis, nowadays it is known that MINOCA can significantly affect patient quality of life and portends a guarded prognosis. Therefore, it is of utmost importance to identify the specific pathophysiological mechanism underlying this clinical condition in order to set up a targeted pharmacological and non-pharmacological therapy. Coronary angiography is still a mandatory diagnostic test to rule out obstructive coronary artery disease but has limited capability to identify other potential functional and structural etiologies of MINOCA. The purpose of this review is to provide an overview of the invasive diagnostic work-up of patients with MINOCA, highlighting the diagnostic tools warranted beyond coronary angiography inside the cath lab (intracoronary provocation tests, intracoronary imaging and indexes for the assessment of coronary microvascular dysfunction), and the remaining essential knowledge gaps in this field.

Immediate versus staged complete revascularization in acute coronary syndrome: A meta-analysis of randomized controlled trials.

BACKGROUND: Clinical guidelines recommend a complete revascularization (CR) in patients with acute coronary syndromes (ACS) and multivessel disease (MVD). However, its optimal timing is unclear. The aim of this meta-analysis was to compare the clinical outcomes following immediate versus staged CR in ACS. METHODS: PubMed and Scopus were searched until March 2023 for randomized controlled trials (RCTs) comparing immediate versus staged CR. The primary endpoint was major adverse cardiovascular event (MACE) at the longest follow-up. Secondary outcomes were all-cause death, cardiovascular death, myocardial infarction (MI), any unplanned revascularization, target-vessel revascularization (TVR), and stent thrombosis. Safety outcomes were major bleeding, contrast volume, procedure duration, and length of hospitalization. RESULTS: Eight RCTs were included (3559 patients, weighted mean follow-up 12.5 months). There were no differences in the primary endpoint (OR 0.74, 95%CI: 0.54-1.01) and in the secondary endpoints of death, and stent thrombosis between the two CR strategies. Immediate CR was associated with a lower risk of recurrent MI (OR 0.51, 95% CI 0.34-0.76), any unplanned revascularization (OR 0.59, 95%CI: 0.43-0.80), and TVR (OR 0.61, 95% CI 0.45-0.84) compared to staged CR. Immediate CR was also associated with lower total contrast volume and shorter total procedure duration and hospitalization length compared to staged CR without differences in major bleedings. CONCLUSION: No difference was found between immediate and staged CR regarding MACE, or deaths rates at one year. Immediate CR may be associated with a lower risk of recurrent MI and unplanned coronary revascularization than staged CR.