Hemodynamic factors and atheromatic plaque rupture in the coronary arteries: from vulnerable plaque to vulnerable coronary segment

Risk of cardiovascular events after influenza infection-related hospitalizations in adults with congenital heart disease: A nationwide population based study

BACKGROUND

Cardiovascular complications due to viral infection pose a significant risk in vulnerable patients such as those with congenital heart disease (CHD). Limited data exists regarding the incidence of influenza and its impact on cardiovascular outcomes among this specific patient population.

METHODS

A retrospective cohort study was designed using the Canadian Congenital Heart Disease (CanCHD) database-a pan-Canadian database of CHD patients with up to 35 years of follow-up. CHD patients aged 40 to 65 years with influenza virus-associated hospitalizations between 2010 and 2017 were identified and 1:1 matched with CHD patients with limb fracture hospitalizations on age and calendar time. Our primary endpoint was cardiovascular complications: heart failure, acute myocardial infarction, atrial arrhythmia, ventricular arrhythmia, heart block, myocarditis, and pericarditis.

RESULTS

Of the 303 patients identified with incident influenza virus-associated hospitalizations, 255 were matched to 255 patients with limb fracture hospitalizations. Patients with influenza virus-related hospitalizations showed significantly higher cumulative probability of cardiovascular complications at 1 year (0.16 vs. 0.03) and 5 years (0.33 vs. 0.15) compared to patients hospitalized with bone fracture. Time-dependent hazard function modeling demonstrated a significantly higher risk of cardiovascular complications within 9 months postdischarge for influenza-related hospitalizations. This association was confirmed by Cox regression model (average hazard ratio throughout follow-up: 2.48; 95% CI: 1.59-3.84).

CONCLUSIONS

This pan-Canadian cohort study of adults with CHD demonstrated an association between influenza virus-related hospitalization and risk of cardiovascular complications during the 9 months post discharge. This data is essential in planning surveillance strategies to mitigate adverse outcomes and provides insights into interpreting complication rates of other emerging pathogens, such as COVID-19.

Myocardial Ischemia in Patients with COVID-19 Infection: Between Pathophysiological Mechanisms and Electrocardiographic Findings

Given the possible pathophysiological links between myocardial ischemia and SARS-CoV-2 infection, several studies have focused attention on acute coronary syndromes in order to improve patients’ morbidity and mortality. Understanding the pathophysiological aspects of myocardial ischemia in patients infected with SARS-CoV-2 can open a broad perspective on the proper management for each patient. The electrocardiogram (ECG) remains the easiest assessment of cardiac involvement in COVID-19 patients, due to its non-invasive profile, accessibility, low cost, and lack of radiation. The ECG changes provide insight into the patient’s prognosis, indicating either the worsening of an underlying cardiac illnesses or the acute direct injury by the virus. This indicates that the ECG is an important prognostic tool that can affect the outcome of COVID-19 patients, which important to correlate its aspects with the clinical characteristics and patient’s medical history. The ECG changes in myocardial ischemia include a broad spectrum in patients with COVID-19 with different cases reported of ST-segment elevation, ST-segment depression, and T wave inversion, which are associated with severe COVID-19 disease.

Potential Influential Factors of In-Hospital Myocardial Reinfarction in ST-Segment Elevation Myocardial Infarction (STEMI) Patients: Finding from the Improving Care for Cardiovascular Disease in China- (CCC-) Acute Coronary Syndrome (ACS) Project

In this study, 39915 inpatients with a discharge diagnosis of STEMI from the CCC-ACS project phase I and II were included. The prevalence of the medical history, clinical complications on admission and treatment during hospitalization in the STEMI inpatients with and without in-hospital reinfarction was presented. The factors that were differentially distributed and of critical clinical significance (e.g., age, sex, heart rate, smoking, MI history, HF history, COPD history, stroke, hypertension, diabetes, PCI treatment, administration of DAPT, and statins) were entered into standard Cox regression model and competing risk model for potential influential factors of in-hospital reinfarction. Patients with a higher heart rate (OR 1.018; 95% CI 1.003 to 1.033) were more susceptible to in-hospital reinfarction. Myocardial infarction history (OR 2.840; 95% CI 1.160 to 6.955) was a risk factor of in-hospital reinfarction independent of hypertension, diabetes, and dyslipidaemia.

COVID-19 and Acute Coronary Syndromes: From Pathophysiology to Clinical Perspectives

Acute coronary syndromes (ACS) are frequently reported in patients with coronavirus disease 2019 (COVID-19) and may impact patient clinical course and mortality. Although the underlying pathogenesis remains unclear, several potential mechanisms have been hypothesized, including oxygen supply/demand imbalance, direct viral cellular damage, systemic inflammatory response with cytokine-mediated injury, microvascular thrombosis, and endothelial dysfunction. The severe hypoxic state, combined with other conditions frequently reported in COVID-19, namely sepsis, tachyarrhythmias, anemia, hypotension, and shock, can induce a myocardial damage due to the mismatch between oxygen supply and demand and results in type 2 myocardial infarction (MI). In addition, COVID-19 promotes atherosclerotic plaque instability and thrombus formation and may precipitate type 1 MI. Patients with severe disease often show decrease in platelets count, higher levels of d-dimer, ultralarge von Willebrand factor multimers, tissue factor, and prolongation of prothrombin time, which reflects a prothrombotic state. An endothelial dysfunction has been described as a consequence of the direct viral effects and of the hyperinflammatory environment. The expression of tissue factor, von Willebrand factor, thromboxane, and plasminogen activator inhibitor-1 promotes the prothrombotic status. In addition, endothelial cells generate superoxide anions, with enhanced local oxidative stress, and endothelin-1, which affects the vasodilator/vasoconstrictor balance and platelet aggregation. The optimal management of COVID-19 patients is a challenge both for logistic and clinical reasons. A deeper understanding of ACS pathophysiology may yield novel research insights and therapeutic perspectives in higher cardiovascular risk subjects with COVID-19.

Heart Rate as a Predictor of Outcome Following Percutaneous Coronary Intervention

Data from previous studies of patients with heart failure and coronary artery disease suggest that those with higher resting heart rates (HRs) have worse cardiovascular outcomes. We sought to evaluate whether HR immediately before percutaneous coronary intervention (PCI) is an independent predictor for 30-day outcome. We analyzed the outcome of 3,720 patients who had HR recorded before PCI from the Melbourne Interventional Group registry. HR and outcomes were analyzed by quintiles, and secondarily by dichotomizing into <70 or ≥70 beats/min. Patients with cardiogenic shock, intra-aortic balloon pump or inotropic support, and out-of-hospital arrest were excluded. The mean ± SD HR was 70.9 ± 14.7 beats/min. HR by quintile was 55 ± 5, 64 ± 2, 70 ± 1, 77 ± 3, and 93 ± 13 beats/min, respectively. Patients with higher HR were more likely to be women, current smokers, have higher systolic and diastolic blood pressure, atrial fibrillation, recent heart failure, lower ejection fraction, and ST-elevation myocardial infarction as the indication for the PCI (all p ≤0.002). However, rates of treated hypertension, multivessel disease, previous myocardial infarction, PCI, and coronary bypass surgery were lower (all p ≤0.004). Increased HR was associated with higher 30-day mortality (p for trend = 0.04), target vessel revascularization (p for trend = 0.003), and 30-day major adverse cardiac events (MACE) (p for trend = 0.004). In a multivariable analysis, HR was an independent predictor of 30-day MACE (OR 1.21 per quintile; 95% confidence interval (CI): 1.06 to 1.39, p = 0.004). When dichotomized into <70 or ≥70 beats/min, HR independently predicted both 30-day MACE (OR 1.59, 95% CI 1.08 to 2.36, p = 0.02) and 30-day mortality (OR 2.80, 95% CI 1.10 to 7.08, p = 0.03). In conclusion, HR immediately before PCI is an independent predictor of adverse 30-day cardiovascular outcomes.

Modelling of thrombin generation under flow in realistic left anterior descending geometries

Currently there are no available methods for prediction of thrombotic complications in Coronary Artery disease. Additionally, blood coagulation tests are mainly performed in a steady system while coagulation in vivo occurs under flow conditions. In this work, a phenomenological model for coagulation up-to thrombin generation is proposed; the model is mainly based on the results of thrombin generation assays and therefore it can account for the variation of the coagulability that is observed in different individuals. The model is applied on 3 cases of left anterior descending arteries (LAD) with 50% maximum stenosis placed at a different location and have been statistically assessed as of different complication risk. The simulations showed that parameters of thrombin generation assays obtain different values when they refer to thrombin generation under realistic coronary flow conditions. The flow conditions prevailing locally because of the geometric differences among the arterial trees can lead to different initiation times and thrombin production rates and it also alters the spatial distribution of the coagulation products. Similarly, small changes of the coagulation characteristics of blood under identical flow conditions can allow or prevent the initiation of coagulation. The results indicate that combined consideration of geometry and coagulation characteristics of blood can lead to entirely different conclusions compared to independent assessment of each factor.

Cardiovascular Screening for the Asymptomatic Patient with Diabetes: More Cons Than Pros

Diabetes mellitus is associated with an increased risk of coronary heart disease (CHD) morbidity and mortality. Although it frequently coexists with other cardiovascular disease (CVD) risk factors, it confers an increased risk for CVD events on its own. Coronary atherosclerosis is generally more aggressive and widespread in people with diabetes (PWD) and is frequently asymptomatic. Screening for silent myocardial ischaemia can be applied in a wide variety of ways. In nearly all asymptomatic PWD, however, the results of screening will generally not change medical therapy, since aggressive preventive measures, such as control of blood pressure and lipids, would have been already indicated, and above all, invasive revascularization procedures (either with percutaneous coronary intervention or coronary artery bypass grafting) have not been shown in randomized clinical trials to confer any benefit on morbidity and mortality. Still, unresolved issues remain regarding the extent of the underlying ischaemia that might affect the risk and the benefit of revascularization (on top of optimal medical therapy) in ameliorating this risk in patients with moderate to severe ischaemia. The issues related to the detection of coronary atherosclerosis and ischaemia, as well as the studies related to management of CHD in asymptomatic PWD, will be reviewed here.

Impact of Longitudinal Lesion Geometry on Location of Plaque Rupture and Clinical Presentations

OBJECTIVES

This study sought to investigate the impact of longitudinal lesion geometry on the location of plaque rupture and clinical presentation and its mechanism.

BACKGROUND

The relationships among lesion geometry, external hemodynamic forces acting on the plaque, location of plaque rupture, and clinical presentation have not been comprehensively investigated.

METHODS

This study enrolled 125 patients with plaque rupture documented by intravascular ultrasound. Longitudinal locations of plaque rupture were identified and categorized by intravascular ultrasound. Patients' clinical presentations and TIMI (Thrombolysis In Myocardial Infarction) flow grade in an initial angiogram were compared according to the location of plaque rupture. Longitudinal lesion asymmetry was quantitatively assessed by the luminal radius change over the segment length (radius gradient [RG]). Lesions with a steeper radius change in the upstream segment compared with the downstream segment (RG_upstream > RG_downstream) were defined as upstream-dominant lesions.

RESULTS

On the basis of the site of maximum rupture aperture, 56.0%, 16.0%, and 28.0% of the patients had upstream, minimal lumen area, and downstream rupture, respectively. Patients with upstream rupture more frequently presented with ST-segment elevation myocardial infarction (45.7%, 40.0%, 22.9%; p = 0.030) and with TIMI flow grade <3 (32.9%, 20.0%, 17.1%; p = 0.042). According to the ratio of upstream and downstream RG, 69.5% of lesions were classified as upstream-dominant lesions, and 30.5% were classified as downstream-dominant lesions. Among the 66 upstream-dominant lesions, 65 cases (98.5%) had upstream rupture, and the RG ratio (RG_upstream/RG_downstream) was an independent predictor of upstream rupture (odds ratio: 1.481; 95% confidence interval: 1.035 to 2.120; p = 0.032). Upstream-dominant lesions more frequently manifested with ST-segment elevation myocardial infarction than did downstream-dominant lesions (48.5% vs. 24.1%; p = 0.026).

CONCLUSIONS

Both clinical presentation and degree of flow limitation were associated with the location of plaque rupture. Longitudinal lesion asymmetry assessed by RG, which can affect regional distribution of hemodynamic stress, was associated with the location of rupture and with clinical presentation.

Relation of Angiographic Thrombus Burden with Severity of Coronary Artery Disease in Patients with ST Segment Elevation Myocardial Infarction

Background

We planned to investigate the relationship of thrombus burden with SYNTAX score in patients with ST elevation myocardial infarction (STEMI).

Material/Methods

We retrospectively enrolled 780 patients who underwent PPCI in our clinic due to STEMI. Clinical, laboratory, and demographic properties of the patients were recorded. Angiographic coronary thrombus burden was classified using thrombolysis in myocardial infarction (TIMI) thrombus grades.

Results

Patients with high thrombus burden were older, with higher diabetes prevalence longer pain to balloon time, higher leukocyte count, higher admission troponin, and admission CK-MB concentrations. SYNTAX score was higher and myocardial perfusion grades were lower in patients with high thrombus burden. Multivariate logistic regression analysis revealed SYNTAX score as the strongest predictor of thrombus burden. ROC analysis demonstrated a sensitivity of 75.5%, specificity of 61.2%, and cut-off value of >14 (area under the curve (AUC): 0.702; 95% confidence interval [CI]: 0.773–0.874;P<0.001) for high thrombus burden.

Conclusions

SYNTAX score may have additional value in predicting higher thrombus burden besides being a marker of coronary artery disease severity and complexity.

Computational fluid dynamics in coronary artery disease

Computational fluid dynamics (CFD) is a widely used method in mechanical engineering to solve complex problems by analysing fluid flow, heat transfer, and associated phenomena by using computer simulations. In recent years, CFD has been increasingly used in biomedical research of coronary artery disease because of its high performance hardware and software. CFD techniques have been applied to study cardiovascular haemodynamics through simulation tools to predict the behaviour of circulatory blood flow in the human body. CFD simulation based on 3D luminal reconstructions can be used to analyse the local flow fields and flow profiling due to changes of coronary artery geometry, thus, identifying risk factors for development and progression of coronary artery disease. This review aims to provide an overview of the CFD applications in coronary artery disease, including biomechanics of atherosclerotic plaques, plaque progression and rupture; regional haemodynamics relative to plaque location and composition. A critical appraisal is given to a more recently developed application, fractional flow reserve based on CFD computation with regard to its diagnostic accuracy in the detection of haemodynamically significant coronary artery disease.

Circulating soluble lectin-like oxidized low-density lipoprotein receptor-1 levels are associated with proximal/middle segment of the LAD lesions in patients with stable coronary artery disease

BACKGROUND/OBJECTIVES

Atherosclerosis is the main underlying pathology of coronary artery disease (CAD), which is the leading cause of mortality worldwide. Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is involved in multiple phases of vascular dysfunction, including endothelial dysfunction, atherosclerotic plaque formation, and destabilization. The purpose of the current study was to determine whether soluble LOX-1 is associated with proximal/mid and distal segment of the left anterior descending (LAD) artery lesion in patients with stable CAD.

METHODS

Sixty-four patients with proximal/mid segment of the LAD lesions and 51 patients with distal segments of the LAD lesions were included in this study. Soluble LOX-1 levels were measured in all study subjects.

RESULTS

Baseline characteristics of the two groups were similar. In stable CAD, patients with proximal/middle segment of the LAD lesions had significantly higher circulating soluble LOX-1 levels than patients with distal segments of the LAD lesions (1.07 ± 0.33 vs. 0.70 ± 0.17 ng/ml, p < 0.001). No correlation was found between plasma-soluble LOX-1 levels and fasting glucose, lipid profile. For predicting proximal/middle LAD lesions, the highest specificity (95,2%) and sensitivity (53,8%) levels were obtained at the cut-off value of 0.68.

CONCLUSION

Our study demonstrated that serum-soluble LOX-1 levels were associated with proximal/mid segment of the LAD lesions. Furthermore, this study suggested soluble LOX-1 might be a useful biomarker of coronary plaque vulnerability in patients with stable CAD. Soluble LOX-1, the novel biochemical marker, may provide new insights into not only risk stratification but also therapeutic strategy for CAD.

Role of acute infection in triggering acute coronary syndromes

Acute coronary syndromes are a leading cause of morbidity and mortality worldwide. The mechanisms underlying the triggering of these events are diverse and include increased coronary and systemic inflammatory activity, dominant prothrombotic conditions, increased biomechanical stress on coronary arteries, variations in the coronary arterial tone, disturbed haemodynamic homoeostasis, and altered myocardial metabolic balance. There is experimental evidence that acute infections can promote the development of acute coronary syndromes, and clinical data strongly support a role for acute infections in triggering these events. In our Review, we summarise the pathogenesis of coronary artery disease and present the evidence linking acute infections with the development of acute coronary syndromes. Greater awareness of this association is likely to encourage research into ways of protecting patients who are at high risk.

Atherothrombosis and plaque heterology: different location or a unique disease?

Formation of unstable plaques frequently results in atherothrombosis, the major cause for ischaemic stroke, myocardial infarction and peripheral arterial disease. Patients who have symptomatic thrombosis in one vascular bed are at increased risk of disease in other beds. However, the development of the disease in carotid, coronary and peripheral arteries may have different pathophysiology suggesting that more complex treatment protocols may have to be designed to reduce plaque development at different locations. In this review we describe the known risk factors, compare the developmental features of coronary and carotid plaque development and determine their association with end-point ischaemic events. Differences are also seen in the genetic contribution to plaque development as well as in the deregulation of gene and protein expression and cellular signal transduction activity of active cells in regions susceptible to thrombosis. Differences between carotid and coronary artery plaque development might help to explain the differences in anatomopathological appearance and risk of rupture.

Anatomic characteristics of culprit sites in acute coronary syndromes

BACKGROUND

A detailed analysis of the anatomic relationships of the site of culprit lesions that have resulted in acute coronary syndromes (ACS) has not been reported.

METHODS

Coronary angiograms of consecutive patients who presented with ACS were analyzed according to multiple anatomic criteria.

RESULTS

In left anterior descending artery (LAD) (n = 85), 85% of culprit lesions were located in the first 40 mm from the ostium. The presence of angulation on the lesion increased the risk of an ACS 1.92 times (95% confidence interval [CI] 1.9-3.07), and the presence of bifurcation after the lesion increased the risk 1.65 times (95% CI 1.04-2.62). Angulated lesions located within the first 40 mm from the ostium and before a bifurcation presented an 11-fold increased risk for an ACS. In right coronary artery (RCA) (n = 58), the risk of plaque rupture was almost 2.5 times higher in lesions located between 10 and 50 mm from the ostium compared to those located in 90-130 mm (relative risk [RR] 2.38, 95% CI 1.25-4.56). In left circumflex (LCx) (n = 40), the risk of plaque rupture was almost 4.5 and 5 times higher in the first 20 mm, and between 20 and 40 mm from the ostium, respectively, compared to 60 and 80 mm (relative risk [RR] 4.58, 95% CI 1.01-20.68 for 0-20 mm, and RR 4.95, 95% CI 1.14-21.47 for 20-40 mm) after adjustment for the presence of curve on the lesion. The presence of lesion angulation increased the risk of plaque rupture almost three times (RR 3.22, 95% CI 1.49-6.93).

CONCLUSION

Specific anatomic features of the coronary arteries predispose to development and/or subsequent rupture of vulnerable plaques.