Coronary Blood Flow Research Articles

Echocardiography-derived regional strain for assessment of non-culprit stenosis and prediction of systolic function recovery in acute STEMI.

To compare echocardiographic regional longitudinal strain with quantitative coronary angiography and assess temporal changes in regional strain in patients with STEMI and multivessel coronary artery disease. Thirty-two patients with STEMI and multivessel coronary artery disease underwent coronary angiography with 3D quantification and baseline echocardiography. Regional longitudinal strain was measured as the average strain of three adjacent myocardial segments (RLS-3S) with the most impaired strain values. Forty-one stenosed vessels were identified (9 LAD [19%], 21 LCx [50%] and 11 RCA [31%]). RLS-3S did not correlate with diameter stenosis, area stenosis or minimal luminal diameter. Receiver operating curve analysis of RLS-3S for hemodynamic significant lesions (defined as positive fractional flow reserve or composite of ≥ 70% diameter stenosis and minimal luminal diameter < 1.2mm) demonstrated an area under the curve of 0.63 (95% CI 0.45-0.76) with an optimal cut-off value of < 9.8%. Sensitivity and specificity of RLS-3S was 86% (42-100) and 48% (31-66). RLS-3S < 9.8% at baseline in remote myocardium subtended by the stenosed coronary vessel predicted benefit from percutaneous coronary intervention in terms of regional functional recovery. RLS-3S does not correlate with individual coronary angiography measures and moderately predicts hemodynamically significant lesions. RLS-3S could be used to predict regional functional recovery after additional revascularization.

Correlation between admission blood glucose, fibrinogen, and slow blood flow during primary PCI for acute ST segment elevation myocardial infarction

BackgroudCoronary slow flow (CSF) is a common phenomenon of coronary microcirculation dysfunction, and is closely related to elevated blood glucose and fibrinogen (FIB) levels. However, whether immediate blood glucose and FIB levels affect coronary blood flow during primary percutaneous coronary intervention (PCI) remains unclear.ObjectiveTo explore the correlation between admission blood glucose (ABG), fibrinogen (FIB) and slow blood flow during primary PCI for acute ST segment elevation myocardial infarction (STEMI).MethodsA total of 497 patients who underwent coronary angiography in the cardiology department of the 904th Hospital of the Joint Logistics Support Force from December 2018 to December 2022 due to STEMI were selected consecutively, and then were divided into two groups based on whether slow blood flow occurred during primary PCI: slow blood flow group (n = 117) and control group (n = 380). Detecting the ABG, FIB and other indicators of patients in each group, and using logistic regression analysis and receiver operating characteristic (ROC) curve to analyze independent risk factors for slow blood flow during primary PCI, and further evaluating the prognosis of patients.ResultsThe levels of ABG and FIB in patients with slow blood flow were significantly higher than those in the control group (P &amp;lt; 0.05). The results of multivariate logistic regression analysis suggested that FIB and ABG were independent risk factors for slow blood flow during primary PCI (both P &amp;lt; 0.05). ROC curve analysis showed that ABG, FIB, and their combination all had predictive value for slow blood flow during primary PCI (all P &amp;lt; 0.05), and the area under the curve (AUC) of the combined indicator was higher than that of any single indicator, with statistical significance (P &amp;lt; 0.05). KM curve analysis suggested that the prognosis of patients in slow blood flow group were poor.ConclusionBoth elevated ABG and FIB could predict slow blood flow during primary PCI, and the diagnostic value of the combined indicator was superior to that of any single indicator, which could be used for the evaluation of slow blood flow during primary PCI, so as to evaluate the prognosis of patients with STEMI.

Coronary Microvascular Dysfunction Is Associated With Augmented Lysosomal Signaling in Hypercholesterolemic Mice.

Accumulating evidence indicates that coronary microvascular dysfunction (CMD) caused by hypercholesterolemia can lead to myocardial ischemia, with or without obstructive atherosclerotic coronary artery disease. However, the molecular pathways associated with compromised coronary microvascular function before the development of myocardial ischemic injury remain poorly defined. In this study, we investigated the effects of hypercholesterolemia on the function and integrity of the coronary microcirculation in mice and the underlying mechanisms. Mice were fed a hypercholesterolemic Paigen's diet for 8 weeks. Echocardiography data showed that Paigen's diet caused CMD, characterized by significant reductions in coronary blood flow and coronary flow reserve, but did not affect cardiac remodeling or dysfunction. Immunofluorescence studies revealed that Paigen's diet-induced CMD was associated with activation of coronary arterioles inflammation and increased myocardial inflammatory cell infiltration. These pathological changes occurred in parallel with the upregulation of lysosomal signaling pathways in endothelial cells (ECs). Treating hypercholesterolemic mice with the cholesterol-lowering drug ezetimibe significantly ameliorated Paigen's diet-induced adverse effects, including hypercholesterolemia, steatohepatitis, reduced coronary flow reserve, coronary endothelial cell inflammation, and myocardial inflammatory cell infiltration. In cultured mouse cardiac ECs, 7-ketocholesterol increased mitochondrial reactive oxygen species and inflammatory responses. Meanwhile, 7-ketocholesterol induced the activation of transcriptional factor EB and lysosomal signaling in mouse cardiac ECs, whereas the lysosome inhibitor bafilomycin A1 blocked 7-ketocholesterol-induced transcriptional factor EB activation and exacerbated 7-ketocholesterol-induced inflammation and cell death. Interestingly, ezetimibe synergistically enhanced 7-ketocholesterol-induced transcriptional factor EB activation and attenuated 7-ketocholesterol-induced mitochondrial reactive oxygen species and inflammatory responses in mouse cardiac ECs. These results suggest that CMD can develop and precede detectable cardiac functional or structural changes in the setting of hypercholesterolemia and that upregulation of transcriptional factor EB-mediated lysosomal signaling in endothelial cells plays a protective role against CMD.

Computed tomography-based anatomic suitability of an Endo-Bentall prosthesis for ascending aortic aneurysms

IntroductionThis study aimed to evaluate the suitability of a coronary-branched ascending aortic endograft, paired with aortic valve (AV) prosthesis (Endo-Bentall), for the endovascular repair of ascending aortic aneurysms. MethodsPre-operative ≤1mm computed tomography angiographies of consecutive patients managed with Bentall procedure or ascending aortic replacement and AV reconstruction/replacement, in a single institution (01.01.2008-31.12.2023), were retrospectively analyzed. Dedicate software was used to assess: (1) vascular access, (2) proximal landing zone, (3) coronary artery anatomy and (4) distal landing. Eligibility criteria for Endo-Bentall were: ≥8mm iliac arteries, without severe calcification/tortuosity, proximal landing with 18-29mm aortic annulus diameter, ≥10mm annulus-coronary ostium distance, no mechanical AV, absence of coronary grafts in the ascending aorta, no left ventricle thrombus, coronary arteries ≥3mm wide and ≥10mm long, with no anatomic abnormalities, ostial stent or stenosis and ≥20mm long and ≤38mm wide distal landing zone within the ascending aorta or applicability of branched endovascular arch repair. ResultsTwenty-nine patients (55.2% females) were included. All patients had adequate proximal landing zone in terms of annulus diameter (median: 25mm, IQR: 5mm). Two (6.8%) had inadequate iliac access (external iliac artery <8mm). Two patients (6.8%) had a mechanical AV. Twenty-six patients (89.6%) had adequate landing zone for stenting of the left main coronary artery (LMCA; median diameter: 5.2mm, IQR: 1.8mm) and 28 (96.6%) had adequate right coronary artery (RCA) landing (median diameter: 4.1, IQR: 1mm). The LMCA and RCA were located at 5:00' and 10:50’ clock positions, respectively. Three patients (20.7%) had an adequate distal landing zone within the ascending aorta. The remaining were suitable for extension with a branched arch device. According to the predefined criteria, 75.9% of patients were anatomically suitable for Endo-Bentall. ConclusionThree out of four patients with ascending aortic aneurysms may be considered as anatomically eligible for endovascular treatment with an Endo-Bentall prosthesis.

Lipoprotein(a) Is Elevated and Inversely Related to Coronary Endothelial Function in People With HIV.

HIV-associated cardiovascular disease (CVD) is increasing in prevalence. The mechanisms underlying the heightened cardiovascular risk faced by people with HIV (PWH), however, remain poorly defined. Recent studies indicate an important role of lipoprotein(a) (Lp[a]) in predicting CVD risk in the general population, but little is known regarding its role in HIV-associated CVD. Thus, we sought to evaluate whether Lp(a) is elevated in PWH and if it is associated with impaired coronary endothelial function (CEF), a known mediator of CVD in PWH. In this cross-sectional study, cardiac magnetic resonance imaging with isometric handgrip exercise, an endothelial dependent stressor, was performed to assess CEF in 65 PWH and 52 controls without HIV. Percent changes in coronary cross-sectional area and coronary blood flow from rest to stress were used to quantify CEF. Lp(a) levels were assessed by immunoturbidimetric assay at the time of magnetic resonance imaging. Lp(a) levels were higher in PWH compared with controls (78 nmol/L [39-137 nmol/L] versus 45.5 nmol/L [18-102.5 nmol/L], P<0.01). Both percent change in coronary cross-sectional area (0.38% [-6.1% to 5.4%] versus 7.43% [2.4%-11.2%], P<0.0005) and coronary blood flow (9.1% [-1.3% to 23.1%] versus 24.1% [3.3%-39.8%], P<0.05) were lower in PWH compared with controls. In PWH, Lp(a) was inversely associated with percent change in coronary cross-sectional area (β=-6.18±1.01%/nmol/L, P<0.001) but not with percent change in coronary blood flow even after adjustment for confounding risk factors. No association between Lp(a) and measures of CEF was observed in individuals without HIV. Lp(a) concentrations are elevated in PWH and inversely related to CEF in PWH.

Influence of a cardiac rehabilitation programme on the return to work of workers with ischaemic heart disease: Influence of a cardiac rehabilitation programme

This study aimed to examine the employment status of patients who have experienced ischemic heart disease one year after undergoing cardiac rehabilitation. For this, a quasi-experimental pre-post study without a control group of active workers aged 18 to 65 years diagnosed with ischemic heart disease and included in a cardiac rehabilitation programme was conducted. Sociodemographic and occupational data, cardiovascular risk factors and clinical-therapeutic data on heart disease were collected. A total of 214 patients were included, of which 115 patients returned to work. Several clinical factors contributing to return to work were identified: preserved left-ventricular ejection fraction (≥55%), &lt; 3 obstructed coronary vessels, and stent revascularisation. Socio-occupational factors that may positively influence return to work were identified: age &lt; 50 years, absence of anxious-depressive symptoms, higher level of education, and occupations with low physical strain. Cardiac rehabilitation is effective in improving cardiac function and health-related quality of life in workers with ischemic heart disease. Return to work and duration of temporary incapacity were associated with clinical-therapeutic variables and psycho-socio-occupational factors, such as type of job, physical strain, anxiety and depression, and age of the worker.

Right ventricle-dependent coronary circulation in pulmonary atresia with intact ventricular septum. About three patients without coronary ostium atresia. Is a transient percutaneous decompression maneuver necessary?

Pulmonary atresia with intact ventricular septum (PA-IVS) is a rare congenital heart disease characterized by a wide morphological spectrum that can be associated with abnormalities in the coronary circulation such as sinusoids, fistulas, stenosis or atresia. Some patients do not present ventriculo-coronary fistulas or intramyocardial sinusoids, other patients do present ventriculo-coronary connections, but only some of the latter will have right ventricle-dependent coronary circulation (RVDCC); timely establishment of the diagnosis of RVDCC is essential, since the prognosis of these patients is generally fatal. There are reports of patients with this type of coronary circulation (RVDCC) who were undergone to univentricular physiology, but this treatment option remains controversial, so the purpose of this manuscript is to share three cases with PA-IVS and RVDCC, their outcome and the reflections they provide us. We conducted a cross-sectional, descriptive, observational study of patients with PA-IVS and RVDCC without atresia of the coronary ostium during the study period. Three patients were identified, the clinical and angiographic characteristics and their evolution are described, and a new technique or maneuver for transient percutaneous decompress of the right ventricle is described theoretically for those cases where there is doubt about RVDCC during the angiographic study. An accurate diagnosis regarding the existence of RVDCC is vital. In some cases, the interpretation of angiography for the diagnosis of RVDCC can be difficult to pinpoint and in many cases, it can be operator dependent, however we consider that is necessary to have a technique or maneuver that can objectively and without doubts determine RVDCC in those cases where angiography is not totally conclusive and thus be able to offer the best therapeutic option.

Rationale and design of the randomised, controlled Percutaneous coronary intervention using Assisted Robotic TechnologY (PARTY) trial

IntroductionPercutaneous coronary intervention (PCI) is performed by interventional cardiologists who, over their career, are exposed to substantial X-ray radiation and also face potential musculoskeletal injuries from the prolonged wearing of...

Association between circulating CTRP9 levels and coronary artery disease: a systematic review and meta-analysis.

C1q tumor necrosis factor (TNF) related proteins 9 (CTRP9) is a novel adipocytokine that has been shown to have a cardioprotective effect in coronary artery disease (CAD). However, there are conflicting results on circulating levels of CTRP9 in patients with and without CAD. This meta-analysis was conducted to investigate the association between circulating CTRP9 levels and CAD. The aim of this meta-analysis was to re-examine the relationship between circulating CTRP9 levels and CAD. We searched PubMed, Web of Science, Embase, Cochrane Library, CNKI, VIP, Wanfang Data, and CBM for relevant studies up to October 2023, and 193 articles were identified. After reading the title, abstract and full text, a total of 25 articles were included in this meta-analysis. A prespecified protocol registered at INPLASY was followed (INPLASY202450066). Due to the high heterogeneity, we performed subgroup analyses and meta-regression based on patient characteristics, complications, clinical biochemical indicators, coronary artery lesion, and CAD classification. Publication bias was assessed using Egger's linear regression tests, Begg's rank correlation tests, and funnel plots. The results showed that the patient with CAD had significantly lower circulating CTRP9 levels than the control group (Z = 3.26, P = 0.001). Subgroup analysis and meta-regression findings demonstrated that observed heterogeneity could be attributed to population distribution. Patient characteristics (year of publication, patients' age, and BMI), complications (diabetes and type 2 diabetes mellitus (T2DM)), clinical biochemical indicators, coronary artery lesion (stability of coronary atherosclerotic plaque, and the number of diseased coronary vessels), and classification of CAD were not identified as source of heterogeneity. The meta-analysis confirmed that circulating CTRP9 levels in CAD patients are significantly lower than those in patients without CAD. The association may be modified by the population distribution.

Changes of coronary blood flow before and after post-dilation following primary percutaneous coronary intervention in patients with STEMI.

This retrospective cohort study aimed to examine changes in coronary blood flow before and after post-dilation following primary percutaneous coronary intervention (PPCI) in patients with ST-segment elevation myocardial infarction (STEMI). 419 eligible patients who underwent PPCI due to STEMI between January 2019 and September 2023 were enrolled. The corrected thrombolysis in myocardial infarction frame count (CTFC), final quantitative coronary angiography, and the incidence of no-reflow and slow-flow during different procedure moments were assayed. The changes in coronary blood flow before and after post-dilation in the post-dilation group were analyzed. Among the 419 patients enrolled, 259 patients underwent post-dilation. The post-dilation procedure was more frequently performed in patients with calcium plaque present, longer stents, bigger-diameter stents, and overlapping stents. The incidence of final no-reflow and slow-flow in the post-dilation group was not significantly higher than that observed in the non-post-dilation group. In contrast post-dilation patients had significantly increased CTFC values by 3.54 ± 10.54 frames (P < .001) and the rate of no-reflow/slow-flow increased on average by 114% (P < .001) in comparison to patients not undergoing post-dilation. The receiver operating characteristic curve showed that if post-dilation was performed in patients when their after-stent CTFC was smaller than 23.25, no-reflow/slow-flow was less likely to occur (63.5% sensitivity, 88.8% specificity, [AUC]: 0.817, 95% CI: 0.749-0.886, P < .001). Post-dilation exacerbates the coronary blood flow and increases the incidence of no-reflow/slow-flow during PPCI for STEMI patients, except where after-stend CTFC values were <23.25.

Clinically suspected acute right ventricular fulminant dengue myocarditis masquerading with dual lethal arrhythmias: a case report

BackgroundAcute right ventricular myocarditis is rare, comprising only 18% of myocarditis cases. Despite being relatively infrequent at 12.4%, dengue-induced myocarditis has a high mortality risk of 26.4%. This report presents a novel case of acute fulminant right ventricular myocarditis due to severe dengue infection, complicated by dual electrical disturbances: complete heart block and ventricular tachycardia.Case reportA 49-year-old Asian male patient was referred to our hospital with a temporary pacemaker due to a complete heart block. He had a history of recurrent syncope over three days and a fever five days before admission. Initial electrocardiography showed a total atrioventricular nodal block progressing to a high-degree atrioventricular block with a left bundle branch block, indicating an infra-Hisian block. Laboratory findings included thrombocytopenia, elevated troponin, high creatinine, increased liver transaminases, and a positive dengue nonstructural protein 1 test, confirming a diagnosis of dengue infection. Echocardiography showed reduced right ventricular systolic function, normal left ventricular systolic function (ejection fraction: 50%), and dyskinetic intraventricular septum. Coronary angiography revealed normal coronary anatomy. An endomyocardial biopsy was deferred due to severe thrombocytopenia. On the third day, the patient's condition worsened, developing cardiogenic shock and left ventricular systolic dysfunction (ejection fraction: 35%). He subsequently experienced a seizure and slow ventricular tachycardia originating from the right coronary cusp, followed by cardiac arrest. The patient’s family claimed not to resuscitate the patient. Furthermore, the patient died shortly after.ConclusionThis case underscores the critical need for prompt diagnosis and aggressive management of clinically suspected acute fulminant right ventricular myocarditis because complications can rapidly progress to left ventricular systolic dysfunction, leading to cardiogenic shock and sudden cardiac death.

Dynamic CT myocardial perfusion combined with coronary CT angiography for detecting hemodynamical significance of coronary artery stenosis: a comparative study

This study aimed to evaluate the diagnostic performance of combined dynamic stress CT myocardial perfusion imaging (CTP) and coronary CT angiography (CTA) alongside CT-derived fractional flow reserve (CT-FFR) in detecting hemodynamically significant coronary artery disease (CAD). A total of 33 patients (86 vessels) who underwent coronary CTA, dynamic stress CTP, and coronary angiography were included. Vessels exhibiting 30–90% stenosis were subjected to FFR analysis based on coronary angiography (Angio-FFR). Hemodynamic significance, determined by Angio-FFR ≤ 0.80, and imaging findings were evaluated. The evaluation involved a comparison between the combined use of coronary CTA, CTP and CT-FFR, versus the sole use of coronary CTA. Out of 86 coronary vessels, 17 (19.8%) exhibited hemodynamically significant stenosis. The sensitivity, specificity, and accuracy of coronary CTA for detecting ischemia were 94.12%, 34.78%, and 46.51%, respectively. Adding CTP to CTA improved specificity to 88.41%, and accuracy to 87.21%, respectively. The area under the curve (AUC) for the discrimination of functional significant stenosis was 0.798 when using CTA alone, and for CTA plus CTP, it reached 0.910. Furthermore, the combination of CTA, CTP and CT-FFR, showed accuracy of 88.37%, sensitivity of 88.24% and specificity of 88.41% with the AUC of 0.946. The integration of dynamic CTP with CTA significantly enhances the diagnostic accuracy for identifying patients with hemodynamically significant CAD, compared to the use of CTA alone. This study underscores the value of combining CTP, CT-FFR, and CTA in improving diagnostic precision for CAD. The combination of CTP, CT-FFR and CTA offers a multifaceted assessment for patients with CAD by simultaneously providing anatomical detail, functional analysis, and physiological quantification, which facilitating rapid, accurate, and optimal clinical decision-making and significantly enhances patient management.

Abstract 4123637: Prevalence of Invasively Diagnosed Coronary Endothelial Dysfunction in Patients with Chest Pain and Normal Coronary Flow Reserve: The Systematically Missed Diagnosis on Non-invasive Testing

Background: Invasive coronary reactivity testing (CRT) is the gold standard for comprehensive assessment of coronary endothelial and microvascular dysfunction in patients with angina and non-obstructive CAD (ANOCA). Non-invasive imaging modalities (PET and CMR) have emerged as potential alternatives. However, due to the inability to systemically administer acetylcholine, patients with normal coronary flow reserve (CFR) but abnormal endothelial function on invasive Ach testing are systemically missed on non-invasive testing. We aimed to assess the prevalence of coronary endothelial dysfunction in ANOCA patients with normal CFR. Methods: Consecutive patients undergoing CRT at our institution were included. Those with normal adenosine-based CFR (&gt;2.5), were further stratified as having normal coronary endothelial function (NEF, &lt;20% epicardial coronary diameter constriction and &gt;50% increase in coronary blood flow in response to ACh) vs abnormal endothelial function (AEF, &gt;20% epicardial coronary diameter constriction and/or &lt;50% increase in coronary blood flow in response to Ach). We then assessed the proportion of AEF patients who would have been otherwise diagnosed with normal coronary physiology based on CFR alone on non-invasive testing. Results: 37 patients underwent CRT. Mean age was 55 years ± 25, 68% were females. 25 out of 37 patients (68%) had normal CFR. Of those patients, 17 (68%) patients had AEF. Distribution of coronary epicardial vs microvascular endothelial dysfunction is represented in Fig. 1. Conclusion: 68% of ANOCA patients with normal CFR had coronary epicardial and/or microvascular endothelial dysfunction and would have otherwise been labeled as ‘normal coronary physiology’ by non-invasive microvascular function testing. Our findings re-enforce the need for comprehensive invasive CRT for accurate comprehensive diagnosis of patients with ANOCA.

Abstract 4134707: Metabolomics Discovery and Epicardial Adipose Tissue : a PROMISE Clinical Trial Substudy

Introduction: Epicardial adipose tissue (EAT) is a metabolically active tissue associated with cardiometabolic disease. EAT likely has local paracrine inflammatory and atherogenic effects on coronary vessels, but the metabolic underpinnings related to systemic metabolic pathways has not been evaluated. Hypothesis: We hypothesized that metabolic markers of lipid and fatty acid oxidation will be positively associated with volume of EAT. Methods: In a biomarker substudy of the Prospective Multicenter Imaging Study for Evaluation of Chest Pain (PROMISE) clinical trial which randomized participants to computed tomography angiography (CTA) vs. stress testing, we analyzed 1542 participants randomized to the CTA arm with available plasma at baseline. CTA phenotyping of EAT volume indexed to body surface area (cm 3 /m 2 ) was determined using a validated deep-learning algorithm. Comprehensive metabolomic profiling was performed on plasma samples using mass spectrometry. Principal components analysis (PCA) was used for dimensionality reduction of 571 named metabolites. Linear regression tested the association of metabolomic factors with EAT. Univariate models were adjusted for multiple comparisons and multivariate models were adjusted for age, race and ethnicity, sex, diabetes, BMI, LDL-C, HDL-C and metabolic syndrome. Results: Of 82 PCA-derived metabolomic factors, 16 were associated with EAT in univariate models and nine were associated with EAT in multivariate models (p=0.001-0.046); 116 individual metabolites heavily loaded within these factors were significantly associated with EAT volume in multivariate models ( Figure 1 ). This included three linoleic acid derivatives, six cholesterol esters, and glycine that were inversely associated with EAT volume (p&lt;0.04) and 106 metabolites positively associated with EAT volume including di- and triacylcerols, glycerophospholipids, fatty acyls and dimethylguanidino valeric acid (p&lt;0.05). Conclusions: Leveraging a large clinical trial of CTA to study metabolomics of EAT, we have identified circulating lipid species associated with EAT independent of BMI and conventional lipids. These findings highlight biomarkers of systemic metabolic dysregulation as risk modifiers and therapeutic targets in cardiometabolic disease prevention and treatment.

Acute Severe Chest Pain with ST-Segment Elevation in Inferior Leads During Pharmacological Cardioversion of Paroxysmal Supraventricular Tachycardia: A Case Report

Paroxysmal supraventricular tachycardia (PSVT) is a frequently encountered arrhythmia in emergency departments, significantly affecting cardiac function and hemodynamics. The sudden onset of severe chest pain with accompanying ST-segment elevation on the electrocardiogram (ECG) during pharmacological cardioversion is rare but requires immediate intervention with coronary vasodilators, anticoagulants, and antiplatelet agents. Continuous ECG monitoring and assessment of cardiac biomarkers are essential. In facilities with appropriate resources, urgent coronary angiography is recommended to evaluate coronary anatomy, blood flow, and collateral circulation. Due to the rarity of this presentation, we report this case as a reference for clinical diagnosis and management.

Abstract 4132838: Coronary Collaterals Provide Cardioprotection in Hemorrhagic ST-elevation MI (STEMI)

Introduction: Development of intramyocardial hemorrhage (IMH) in acute STEMI following reperfusion is estimated to affect 35-50% of patients. IMH is a lethal event as it contributes to larger MI size, compromised myocardial salvage, adverse left ventricular (LV) remodeling, lower LVEF, and consequential major adverse CV events post-MI. Whether coronary collateral circulation reduces the deleterious effects of IMH has not been investigated. Hypothesis: We hypothesized that coronary collaterals could reduce the extent of post-reperfusion IMH volume and offer cardioprotection to hemorrhagic MI patients. Methods: MIRON-CL (NCT05898425) recruited and studied STEMI patients (n=294) reperfused via PCI. Pre-PCI coronary angiography allowed for assessment of collateral vessels using the Rentrop grading system, from Grade 0 (no collaterals) to Grade III (complete collateral filling). Post-PCI cardiac MRI, performed 3 days later, was used to determine area affected (extent of myocardial edema) from T2 maps, extent of IMH from T2* maps and MI size from LGE as %LV. Statistical analyses were used to examine relationships between collateral grades, MI size, IMH, and area affected. Results: 124 patients were hemorrhagic and 170 were non-hemorrhagic. Patients with no collaterals (Grade 0; CL-) exhibited significantly higher IMH volumes (7.41 ± 5.33% LV) compared to those with collaterals (Grade I: 5.23 ± 3.21% LV, Grade II: 3.11 ± 2.78% LV, Grade III: 2.05 ± 1.89% LV; p&lt;0.001). Total area affected post-PCI was larger in CL- (37.62 ± 15.32% LV) compared to CL+ (21.48 ± 13.21% LV, p&lt;0.001). Presence of collateral circulation (Grade&gt;0 combined; CL+) was correlated with smaller MI sizes (CL-: 38.66 ± 14.63% LV vs. CL+: 19.84 ± 13.72% LV, p&lt;0.001) and reduced MVO volumes (CL-: 8.07 ± 6.60% LV vs. CL+: 2.17 ± 2.35% LV, p&lt;0.001). Patients with no collaterals had a significantly higher adj. risk of IMH (OR: 5.71, 95% CI: 3.16-10.33, p&lt;0.0001). Conclusion: Coronary collaterals reduce post-reperfusion IMH volume in STEMI patients and provide significant cardioprotection: reductions in area affected, MVO and MI size. Insight into collateral grade offers opportunities to improve risk stratification and management of revascularized STEMI patients.

Abstract 4120912: Non-Alcoholic Fatty Liver Disease is Associated with Coronary Flow Reserve Impairment: A Pilot Meta-Analysis

Background: Non-alcoholic fatty liver disease (NAFLD) is estimated to affect approximately 25% of the global population. Significant epidemiological data links NAFLD to an increased risk of coronary artery disease. Both, coronary artery disease and NAFLD are linked to underlying insulin resistance and inflammation as drivers of the disease. Coronary flow reserve parameters including coronary flow reserve velocity (CFRV), baseline diastolic peak flow velocity (DPFV), and hyperemic DPFV are non-invasive markers of coronary microvascular circulation. The existing literature contains conflicting findings for these parameters in NAFLD patients. Aim: This meta-analysis aimed to compare CFRV, baseline DPFV, and hyperemic DPFV in between NAFLD patients and healthy controls. Methods: A comprehensive systematic search was conducted on PubMed, Embase, Cochrane Library, and Google Scholar from inception until 8th May 2024 to identify relevant studies. We pooled the standardized mean differences (SMD) with the 95% confidence intervals (CI) using the inverse variance random-effects model. A p-value of less than 0.05 was considered statistically significant. Results: We included 4 studies with 1139 participants (226: NAFLD and 913: controls). The mean age in the NAFLD group was 54.55 ± 7.62 years and in the control group was 54.2 ± 7.6 years. NAFLD was associated with a significantly lower CFRV [SMD: -0.77; 95% CI: -1.19, -0.36; p&lt;0.0002] and hyperemic DPFV [SMD: -0.73; 95% CI: -1.03, -0.44; p&lt;0.00001] compared to the controls. NAFLD demonstrated a statistically insignificant trend towards reduction in the baseline DPFV [SMD: -0.09; 95% CI: -0.38, 0.19; p=0.52] as compared to healthy controls. Conclusion: NAFLD patients are at a higher risk of coronary microvascular dysfunction as demonstrated by reduced CFRV and hyperemic DPFV. The presence of abnormal coronary flow reserve in NAFLD patients provides insights into the higher rates of cardiovascular disease in these patients. Early aggressive targeted interventions towards impaired coronary flow reserve in NAFLD subjects may lead to improvement in clinical outcomes.

Abstract 4120749: GPR39 Orchestrates the Myogenic Response in Coronary Autoregulation

Background: Coronary autoregulation is the ability of a normal heart to maintain constant coronary blood flow (CBF) over a wide range of coronary driving pressures (CDPs) provided cardiac work remains constant. It is based on the myogenic response, the molecular mechanism of which is unknown. We recently described the presence of a G-protein coupled receptor (GPR39) in the vascular smooth muscle cells (VSMCs) of coronary arterioles in the mouse heart. We showed that endogenous eicosanoids, the vasoconstrictor 15-hydroxyeicosatetraenoic acid (15-HETE) and the vasodilator 14,15-epoxyeicosatrienoic acid (14,15 EET). act through this receptor to maintain coronary vascular tone. Hypothesis: We, therefore, hypothesized that GPR39 is the molecular switch responsible for the coronary myogenic response and autoregulation. Methods: We studied 6 anesthetized dogs at baseline and after administration of VC-108, a specific, potent GPR39 antagonist. Both during baseline and drug administration multiple coronary stenoses were created on the left anterior descending coronary artery (LAD). At each stage, heart rate, mean aortic pressure, distal LAD pressure, and right atrial pressure (RAP) were measured, as was CBF. Stenosis severity was defined by the CDP (LAD pressure minus RAP). Results: Mean basal coronary hyperemic response was 3.0 in all anesthetized animals indicating normal vasomotor function. Systemic hemodynamics did not differ between baseline and drug stages. Figure 1 is an example from a single dog where, at baseline, CBF remained constant over a CDP of 40-90 mm Hg indicating intact autoregulation. As expected, CBF declined when CDP fell below the autoregulatory range. After VC-108 administration CBF correlated linearly with CDP, indicating abolishment of the myogenic response. Baseline CDP vs. CBF data from all 6 animals within the autoregulatory range is depicted in Figure 2. No relation is noted between the two indicating intact autoregulation. In contrast, CDP vs. CBF relation is linear in all animals after VC108 is administered over the entire range of CDP’s measured, indicating abolishment of autoregulation (Figure 3). Conclusions: Our results indicate that GPR39 is a potential molecular switch for the regulation of the myogenic response underlying coronary autoregulation. Pharmacological blockage of GPR39 abolishes the myogenic tone. These novel findings set the stage for development of novel pharmacological agents for treatment of coronary artery disease.

Abstract 4137449: Diagnostic Yield and Testing Characteristics of an Invasive Coronary Function Testing Program

Background: Angina, ischemia, or myocardial infarction in the absence of obstructive coronary artery disease (ANOCA, INOCA, or MINOCA) is common and underdiagnosed. Invasive coronary function testing (CFT) for microvascular disease through coronary thermodilution and for coronary vasospasm through coronary reactivity testing can provide definitive diagnoses and improve patient quality of life. Here, we describe a single site experience launching a CFT program and present the diagnostic yield and test characteristics of the first 66 patients. Methods: The first 66 patients who underwent invasive CFT at Mass General Hospital after the launch of the program in 2022 were included. Invasive CFT data and clinical characteristics before and after were entered into a registry. We used descriptive statistics to summarize patient characteristics, diagnostic yield and change in management with invasive CFT. We describe the dose-response and safety of incremental doses of acetylcholine. Results: Among 66 patients (mean age 61.73±11.02 years, 56% female), 17 patients underwent testing at the time of an index angiogram and 49 were scheduled after knowledge of coronary anatomy. Reasons for invasive coronary function testing were post-revascularization angina (n=30, 45.5%), ANOCA (n=21, 31.8%), INOCA (n=9, 13.6%), MINOCA (n=4, 6.1%), and heart transplant patients (n=2, 3%). 24 (36.3%) patients underwent coronary thermodilution only, 6 (9.1%) coronary reactivity testing only , and 36 (54.5%) both. CFT resulted in a definitive diagnosis in 45 (68.1%) of participants – 37.9% with coronary vasospasm only, 13.6% with microvascular dysfunction only, and 16.7% with both. There were 21 (31.8%) patients who remained negative after invasive CFT. Invasive CFT led to a change in management in 46 (70%) patients. For example, nitrate, calcium channel blocker and beta blocker prescriptions were modified in 47%, 50%, and 52.3% of patients, respectively. Among 42 patients who underwent coronary reactivity testing by provocation with intracoronary acetylcholine doses of 20, 100, and 200 mcg, there was a dose-response to angina (18.5%, 70.2%, and 95.2%), ischemic ECG changes (11.1%, 75.7%, and 95.2%), and vessel spasm of greater than 90% (3.7%, 27%, and 57.1%). There was only one safety event(PTCA to re-establish flow after spasm). Conclusions: We demonstrate the safe implementation of an invasive coronary function testing program with very high diagnostic yield and impact on management.

Abstract 4136274: A Case of Myocardial Infarction with Non-obstructive Coronary Arteries (MINOCA) Complicated by a Ventricular Septal Defect (VSD)

Case: A 69-year-old woman with a history of hypertension and tobacco use disorder presented with acute chest pain. The patient was found to have classic anterior ST elevation myocardial infarction (STEMI) pattern on electrocardiogram (ECG) with high-sensitivity troponin of 12,772 ng/L and was taken emergently to the catheterization laboratory. Coronary angiography showed tortuous coronary vessels though without evidence of obstructive coronary artery disease, plaque rupture, ulceration, dissection, or vasospasm. Transthoracic echocardiogram showed an apical ventricular septal defect (VSD) with normal left ventricular systolic function of 60%. Cardiac computed tomography (CT), confirmed a discrete apical VSD that was 7.93 mm in diameter and multiple small VSDs distally in the septum. Right heart catheterization revealed severe left-to-right shunting with a ratio of pulmonary blood flow to systemic blood flow (Qp:Qs) of 2.8. Early surgical repair of the apical VSD was pursued despite known high operative risk given the hemodynamic significance of the shunt. The patient developed ongoing hemodynamic instability from cardiogenic shock with inability to ween from intra-aortic balloon pump (IABP). Unfortunately, because of the location of the residual VSDs and elevated panel-reactive antibody testing of 98%, the patient was deemed to not be a candidate for percutaneous closure or heart transplantation, respectively. Discussion: An acquired ventricular septal defect (VSD) is a rare and catastrophic complication of myocardial infarction, typically with a culprit obstructive coronary artery lesion identified on coronary angiography. Acquired VSDs in myocardial infarction with nonobstructive coronary arteries (MINOCA) is an even more rare phenomenon. Possible causes include low flow, inflammation, intimal disruption, or vasospasm of coronary arteries. Our case highlights that MINOCA can present with life-threatening complications similar to obstructive STEMI. The timing of intervention and treatment approach of acquired VSDs remains an area of debate. The life-threatening effects of VSDs make it critical to manage in a multidisciplinary manner involving advanced imagers, interventional cardiologists, cardiothoracic surgeons, and heart failure specialists. This case emphasizes the importance of maintaining a high index of suspicion for abnormal coronary anatomy, even in patients with MINOCA, and prompt interdisciplinary decision making to reduce mortality.