293 Impact of metabolic syndrome on coronary microvascular dysfunction: a single-centre experience

Aims The purpose of this study was to evaluate whether microvascular dysfunction is more present in patients with metabolic syndrome (MetS) compared to diabetics and hypertensive patients with two angiographic imaging methods, to evaluate the degree of microcirculation dysfunction, the TIMI frame count and Myocardial Blush grade. Both techniques of rapid use and relatively cheap, and allow us to have a good degree of evaluation referred to the function of the coronary microcirculation. Methods and results The study included 445 patients allocated into three groups, 157 in the MetS group, 128 in the diabetics group, and 160 patients in the hypertensive group. All patients accessed to the emergency room for anginal chest pain, all were hospitalized in the cardiac intensive care unit from 2015 to 2020. Inclusion criteria were the presences of chest pain and/or their positive stress test, and epicardial coronary arteries free from stenosis at coronary angiography. We compared the results obtained from the angiographic techniques (TIMI Frame Count and Myocardial Blush Grade) in the two subgroups: MetS vs. hypertensive, and MetS vs. diabetics. In the first subgroup, we analyzed the TFCs of the three vessels in patients with hypertension and comparing them with patients with MetS, we observed that the latter have a worse perfusion condition: the three epicardial coronary vessels have a higher TFC than the hypertensive population (TFC LAD 33.1 ± 5.6 vs. 28.4 ± 5.6, P = 0.018), (TFC RCA 27.2 ± 5.2 vs. 23.1 ± 5.2, P = 0.014) (TFC CX 27.9 ± 5.4 vs. 26.9 ± 5.4, P = 0.03). That indicates slow flow in patients with MetS coronary microcirculation. Analyzing the MBG, however, in the three coronary vessels of patients with hypertension compared to patients with metabolic syndrome, no difference was found in terms of worsening of the coronary microcirculation. Finally comparing the indices that summarize the values of the individual arteries both for the TFC and MBG, was seen as the TMBS is reduced in both groups (7.1 ± 0.49 vs. 7.1 ± 0.6, P-value = 0.04). The TTFC is instead higher in patients with MetS (83.9 ± 5.8 vs. 77.8 ± 6.7, P-value =0.024). Then we performed the same type of comparison between MetS and type 2 diabetic subgroup, in this comparison we observed how by analyzing the TFCs of the three coronary vessels, MetS patients have a slower coronary flow than patients with type 2 diabetes mellitus (TFC LAD 33.1 ± 5.6 vs. 30.6 ± 6.2, P = 0.04), (TFC RCA 27.2 ± 5.2 vs. 25 ± 5.3, P = 0.02), (TFC CX 27.9 ± 5.4 vs. 27.2 ± 5.6, P = 0.05). Comparing MBG of the three coronary vessels instead, the flow is lower in diabetic patients TTFC was higher in patients with metabolic syndrome (83.9 ± 5.8 vs. 82.7 ± 8.6, P-value = 0.02). While TMBS was lower in diabetic patients than in patients with metabolic syndrome (7.1 ± 0.49 vs. 6.7 ± 0.74, P-value = 0.01). Conclusions This study shows that patients with MetS had a major coronary microvascular dysfunction using TFC imaging technique, analysis compared to diabetics or hypertensive patients, these differences resulted to be statistically significant. A clinical evaluation of this parameters using TFC such in this study, might give further information about (CMD) in this patients in order to act to develop the best treatment to this patients and to improve their clinical condition.

Myocardial Perfusion in Hypoplastic Left Heart Syndrome: Risk Factors for the Right Ventricular Microcirculation

Background: The status of the systemic right ventricular coronary microcirculation in hypoplastic left heart syndrome (HLHS) is largely unknown. It is presumed that the systemic right ventricle’s coronary microcirculation exhibits unique pathophysiological characteristics of HLHS in Fontan circulation. The present study sought to quantify myocardial blood flow by cardiac magnetic resonance imaging and evaluate the determinants of microvascular coronary dysfunction and myocardial ischemia in HLHS. Methods: One hundred nineteen HLHS patients (median age, 4.80 years) and 34 healthy volunteers (median age, 5.50 years) underwent follow-up cardiac magnetic resonance imaging ≈1.8 years after total cavopulmonary connection. Right ventricle volumes and function, myocardial perfusion, diffuse fibrosis, and late gadolinium enhancement were assessed in 4 anatomic HLHS subtypes. Myocardial blood flow (MBF) was quantified at rest and during adenosine-induced hyperemia. Coronary conductance was estimated from MBF at rest and catheter-based measurements of mean aortic pressure (n=99). Results: Hyperemic MBF in the systemic ventricle was lower in HLHS compared with controls (1.89±0.57 versus 2.70±0.84 mL/g per min; P <0.001), while MBF at rest normalized by the rate-pressure product, was similar (1.25±0.36 versus 1.19±0.33; P =0.446). Independent risk factors for a reduced hyperemic MBF were an HLHS subtype with mitral stenosis and aortic atresia ( P =0.017), late gadolinium enhancement ( P =0.042), right ventricular diastolic dysfunction ( P =0.005), and increasing age at total cavopulmonary connection ( P =0.022). The coronary conductance correlated negatively with systemic blood oxygen saturation (r, −0.29; P =0.02). The frequency of late gadolinium enhancement increased with age at total cavopulmonary connection ( P =0.014). Conclusions: The coronary microcirculation of the systemic ventricle in young HLHS patients shows significant differences compared with controls. These hypothesis-generating findings on HLHS-specific risk factors for microvascular dysfunction suggest a potential benefit from early relief of frank cyanosis by total cavopulmonary connection.

The association between invasive microvascular function and CMR-derived microvascular injury indicators and left ventricular function and infarct size at 1-month after reperfused STEMI

Background The restoration of the coronary microcirculation in ST-segment elevation myocardial infarction (STEMI) patients remains hampered in up to 50% of the STEMI patients after successful primary percutaneous coronary intervention (PCI). The association between the coronary microvascular function and injury indicators and functional outcome remains debated. Purpose This study aims to investigate the relation between post-PCI invasive microvascular function and cardiovascular magnetic resonance (CMR)-derived microvascular injury indicators and left ventricular (LV) function and infarct size (IS) at 1-month after STEMI. Methods The study was performed in 110 STEMI patients who underwent angiography for primary PCI and at 1-month follow-up. Invasive assessment of coronary microcirculation physiology in the culprit artery was performed during both procedures and included coronary flow reserve (CFR) and the index of microcirculatory resistance (IMR). Data were available for 101 patients. A ratio of &gt;2 for CFR and a value of &lt;25 U for IMR were considered normal. CMR was performed during the acute phase (2 to 7 days after PCI) and at 1-month and provided assessment of LV function, IS and non-invasive information of microvascular injury in 78 patients by microvascular obstruction (MVO) and intra-myocardial hemorrhage (IMH). Results Over 1-month, CFR, IMR, LV function, and IS all significantly improved (p≤0.001). In univariable linear regression analysis, the post-PCI normal index CFR and IMR (both p=0.04), MVO presence, MVO size, IMH presence, IMH size (all, p&lt;0.001) were significantly associated with LV ejection fraction at 1-month. Additionally, the post-PCI index CFR (p=0.04), MVO presence, MVO size, IMH presence, IMH size (all, p&lt;0.001) were all associated with 1-month IS. In a multivariable linear regression analysis model including invasive and non-invasive coronary microcirculation function and injury indicators, MVO presence was identified as the only independent marker related to both 1-month LV ejection fraction and IS (both p&lt;0.001). Conclusion(s) In STEMI patients, CMR-derived coronary microcirculation injury indicators reveal a closer association with 1-month LV function and IS outcome than invasive microcirculatory measurements. MVO presence is independently associated with 1-month LV ejection fraction and IS. FUNDunding Acknowledgement Type of funding sources: Private company. Main funding source(s): The REDUCE-MVI study was funded by Astra Zeneca to MvL and NvR.

The role of coronary physiology in contemporary percutaneous coronary interventions.

: Invasive assessment of coronary physiology has radically changed the paradigm of myocardial revascularization in patients with coronary artery disease. Despite the prognostic improvement associated with ischemia-driven revascularization strategy, functional assessment of angiographic intermediate epicardial stenosis remains largely underused in clinical practice. Multiple tools have been developed or are under development in order to reduce the invasiveness, cost, and extra procedural time associated with the invasive assessment of coronary physiology. Besides epicardial stenosis, a growing body of evidence highlights the role of coronary microcirculation in regulating coronary flow with consequent pathophysiological and clinical and prognostic implications. Adequate assessment of coronary microcirculation function and integrity has then become another component of the decision-making algorithm for optimal diagnosis and treatment of coronary syndromes. This review aims at providing a comprehensive description of tools and techniques currently available in the catheterization laboratory to obtain a thorough and complete functional assessment of the entire coronary tree (both for the epicardial and microvascular compartments).