The many faces of myocardial ischaemia and angina

Multi-Omics Research on Angina Pectoris: A Novel Perspective

Angina pectoris (AP), a clinical syndrome characterized by paroxysmal chest pain, is caused by insufficient blood supply to the coronary arteries and sudden temporary myocardial ischemia and hypoxia. Long-term AP typically induces other cardiovascular events, including myocardial infarction and heart failure, posing a serious threat to patient safety. However, AP's complex pathological mechanisms and developmental processes introduce significant challenges in the rapid diagnosis and accurate treatment of its different subtypes, including stable angina pectoris (SAP), unstable angina pectoris (UAP), and variant angina pectoris (VAP). Omics research has contributed significantly to revealing the pathological mechanisms of various diseases with the rapid development of high-throughput sequencing approaches. The application of multi-omics approaches effectively interprets systematic information on diseases from the perspective of genes, RNAs, proteins, and metabolites. Integrating multi-omics research introduces novel avenues for identifying biomarkers to distinguish different AP subtypes. This study reviewed articles related to multi-omics and AP to elaborate on the research progress in multi-omics approaches (including genomics, transcriptomics, proteomics, and metabolomics), summarized their applications in screening biomarkers employed to discriminate multiple AP subtypes, and delineated integration methods for multi-omics approaches. Finally, we discussed the advantages and disadvantages of applying a single-omics approach in distinguishing diverse AP subtypes. Our review demonstrated that the integration of multi-omics technologies is preferable for quick and precise diagnosis of the three AP types, namely SAP, UAP, and VAP.

Relationship of Subendocardial Perfusion to Myocardial Injury, Cardiac Structure, and Clinical Outcomes Among Patients With Hypertension

BACKGROUND

Coronary microvascular dysfunction has been implicated in the development of hypertensive heart disease and heart failure, with subendocardial ischemia identified as a driver of sustained myocardial injury and fibrosis. We aimed to evaluate the relationships of subendocardial perfusion with cardiac injury, structure, and a composite of major adverse cardiac and cerebrovascular events consisting of death, heart failure hospitalization, myocardial infarction, and stroke.

METHODS

Layer-specific blood flow and myocardial flow reserve (MFR; stress/rest myocardial blood flow) were assessed by 13N-ammonia perfusion positron emission tomography in consecutive patients with hypertension without flow-limiting coronary artery disease (summed stress score <3) imaged at Brigham and Women's Hospital (Boston, MA) from 2015 to 2021. In this post hoc observational study, biomarkers, echocardiographic parameters, and longitudinal clinical outcomes were compared by tertiles of subendocardial MFR (MFRsubendo).

RESULTS

Among 358 patients, the mean age was 70.6±12.0 years, and 53.4% were male. The median MFRsubendo was 2.57 (interquartile range, 2.08-3.10), and lower MFRsubendo was associated with older age, diabetes, lower renal function, greater coronary calcium burden, and higher systolic blood pressure (P<0.05 for all). In cross-sectional multivariable regression analyses, the lowest tertile of MFRsubendo was associated with myocardial injury and with greater left ventricular wall thickness and volumes compared with the highest tertile. Relative to the highest tertile, low MFRsubendo was independently associated with an increased rate of major adverse cardiac and cerebrovascular events (adjusted hazard ratio, 2.99 [95% CI, 1.39-6.44]; P=0.005) and heart failure hospitalization (adjusted hazard ratio, 2.76 [95% CI, 1.04-7.32; P=0.042) over 1.1 (interquartile range, 0.6-2.8) years median follow-up.

CONCLUSIONS

Among patients with hypertension without flow-limiting coronary artery disease, impaired MFRsubendo was associated with cardiovascular risk factors, elevated cardiac biomarkers, cardiac structure, and clinical events.

Occurrence of Transient Myocardial Ischemic Events Among Non-ST Segment Elevation Acute Coronary Syndrome Patients Before or After Invasive Coronary Angiography

BACKGROUND

The occurrence of transient myocardial ischemia (TMI) is an important pathology in patients with non-ST elevation acute coronary syndrome (NSTE-ACS), yet studies are scarce regarding when TMI occurs during hospitalization, particularly in relation to invasive coronary angiography (ICA). This study examined: (1) TMI before or after ICA; (2) patient characteristics and ischemic burden by TMI group (before or after ICA); and (3) major in-hospital complications (transfer to critical care, death) and length of stay by TMI group (before or after ICA).

METHODS

Secondary data analysis in hospitalized NSTE-ACS patients with TMI event(s) identified from 12-lead electrocardiographic Holter. Patient records were reviewed to assess ischemic burden [TMI time (min) ÷ hours recording duration], outcomes, and TMI timing, before or after ICA.

RESULTS

In 38 patients, 3 (8%) had TMI before and after ICA. Of the remaining 35 patients (92%), TMI occurred before ICA (16; 46%), and after ICA (9; 26%), and 10 (28%) did not have ICA. Patient characteristics, untoward outcomes, and TMI duration (minutes) did not differ by group. Ischemic burden was higher in patients with TMI after ICA (7.29 ± 8.82 min/h) compared to before ICA (2.54 ± 2.11 min/h), P = 0.039. Hospital length of stay by TMI group was 113 ± 113 (before), 226 ± 244 (after), and 85 ± 65 hours (no ICA); P = 0.172.

CONCLUSIONS

Almost half of the sample had TMI before ICA; one-third had TMI but did not have ICA. Patients with TMI after an ICA had a higher ischemic burden. Future studies with larger sample sizes are needed to investigate further the short- and long-term clinical significance of TMI among NSTE-ACS patients.

Effects of major air pollutants on angina hospitalizations: a correlation study

BACKGROUND

Angina is a crucial risk signal for cardiovascular disease. However, few studies have evaluated the effects of ambient air pollution exposure on angina.

OBJECTIVE

We aimed to explore the short-term effects of air pollution on hospitalization for angina and its lag effects.

METHODS

We collected data on air pollutant concentrations and angina hospitalizations from 2013 to 2020. Distributed lag nonlinear model (DLNM) was used to evaluate the short-term effects of air pollutants on angina hospitalization under different lag structures. Stratified analysis by sex, age and season was obtained.

RESULTS

A total of 39,110 cases of angina hospitalization were included in the study. The results showed a significant positive correlation between PM2.5, SO2, NO2, and CO and angina hospitalization. Their maximum harmful effects were observed at lag0-7 (RR = 1.042; 95% CI: 1.017, 1.068), lag0-3 (RR = 1.067; 95% CI: 1.005, 1.133), lag0-6 (RR = 1.078; 95% CI: 1.041, 1.117), and lag0-6 (RR = 1.244; 95% CI: 1.109, 1.397), respectively. PM10 did not have an overall risk effect on angina hospitalization, but it did have a risk effect on women and the elderly. O3 was significantly negatively correlated with angina hospitalization, with the most pronounced effect observed at lag0-6 (RR = 0.960; 95% CI: 0.940, 0.982). Stratified analysis results showed that women and the elderly were more susceptible to pollutants, and the adverse effects of pollutants were stronger in the cold season.

CONCLUSION

Short-term exposure to PM2.5, SO2, NO2, and CO increases the risk of hospitalization for angina.

Effects of Ivabradine on Myocardial Perfusion in Chronic Angina: A Prospective, Preliminary, Open-Label, Single-Arm Study

INTRODUCTION

Ivabradine reduces heart rate (HR), episodes of angina, and nitrate consumption, and increases exercise capacity in patients with chronic angina (CA). In this exploratory study, myocardial perfusion scintigraphy (MPS) was used to evaluate changes in the percentage of myocardial ischemia after ivabradine therapy in patients with CA.

METHODS

This prospective, open-label, single-arm study included patients with CA receiving maximum tolerated doses of beta blockers, who had a resting HR ≥ 70 bpm and had experienced ischemia according to MPS during an exercise test at baseline. Participants received ivabradine 5 mg twice daily (titrated according to HR) concomitant with beta blockers. A second MPS was performed after 3 months, without interruption of treatment with beta blockers or ivabradine. The primary outcome was change in the percentage of myocardial ischemia from baseline to 3 months. Time to ischemia during the exercise test, the proportion of patients presenting angina during the exercise test, and health status, assessed using the seven-item Seattle Angina Questionnaire-7 (SAQ-7), were also evaluated.

RESULTS

Twenty patients (3 females) with a mean (± standard deviation [SD]) age of 62.2 ± 6.5 years were included in the study, of whom 55% had diabetes, 70% had previous myocardial revascularization, and 45% had previous myocardial infarction. The percentage of patients with myocardial ischemia significantly decreased from baseline to 3 months after initiation of treatment with ivabradine (- 2.9%; 95% confidence interval [CI] - 0.3 to - 5.5; p = 0.031). Mean time to appearance of ischemia increased from 403 ± 176 s at baseline to 466 ± 136 s at 3 months after initiation of ivabradine (Δ62 s; 95% CI 18-106 s; p = 0.008), and the proportion of patients experiencing angina during the exercise test decreased from 40% at baseline to 5% also at 3 months (p = 0.016). Mean resting HR decreased from 76 ± 7 bpm at baseline to 55 ± 8 bpm at 3 months (p < 0.001). The mean SAQ-7 summary score improved from 69 ± 21 at baseline to 83 ± 12 at 3 months (p = 0.001). No serious adverse effects were reported.

CONCLUSION

Ivabradine added to beta blockers was associated with a reduction in detectable myocardial ischemia by MPS in patients with CA. Infographic available for this article.

TRIAL REGISTRATION

The trial has been retrospectively registered with the Brazilian Registry of Clinical Trials (REBEC) under the following number RBR-5fysqrh (date of registration: 30 November 2023).

The role of coronary microvascular dysfunction in the pathogenesis of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is a common condition with few effective therapies and hence represents a major healthcare burden. The clinical syndrome of HFpEF can be caused by varying pathophysiological processes, with coronary microvascular dysfunction (CMD) proposed as one of the aetiologies, although confirming causality has been challenging. CMD is characterised by the inability of the coronary vasculature to augment blood flow in response to a physiological stressor and has been established as the driver of angina in patients with non-obstructed coronaries (ANOCA), and this has subsequently led to efficacious endotype-directed therapies. CMD is also highly prevalent among sufferers of HFpEF and may represent a novel treatment target for this particular endotype of this condition. This review aims to discuss the role of the microcirculation in the healthy heart how it's dysfunction may precipitate HFpEF and explore the current diagnostic tools available. We also discuss the gaps in evidence and where we believe future research should be focussed.

Elucidation of the Molecular Mechanism of Compound Danshen Dripping Pills against Angina Pectoris based on Network Pharmacology and Molecular Docking

BACKGROUND

Compound Danshen dripping pills (CDDP), a traditional Chinese medicine, has had an extensive application in the treatment of angina pectoris (AP) in China. However, research on the bioactive ingredients and underlying mechanisms of CDDP in AP remains unclear.

OBJECTIVE

In the present study, we explored the major chemical components and potential molecular mechanisms linked to the anti-angina effects of CDDP through the application of network pharmacology and molecular docking.

METHODS

The potential targets of active ingredients in CDDP were sourced from the Traditional Chinese Medicine Systems Pharmacology Database (TCMSP) and the Swiss Target Prediction Database (STPD). Additionally, targets related to angina pectoris (AP) were retrieved from various databases, including Gene Cards, DisGeNET, Dis Genet, the Drug Bank database (DBD), and the Therapeutic Target Database (TDD). Protein- protein interaction networks were also established, and core targets were identified based on their topological significance. GO enrichment analysis and KEGG pathway analysis were conducted using the R software. Interactions between active ingredients and potential targets selected through the above process were investigated through molecular docking.

RESULTS

Seventy-six active ingredients were selected with the following criteria: OB ≥ 30%, DL ≥ 0.18. 383 targets of CDDP and 1488 targets on AP were gathered, respectively. Afterwards, 194 common targets of CDDP and anti-AP targets were defined, of which 12 were core targets. GO enrichment analysis indicated that CDDP acted on AP by response to lipopolysaccharide, regulating the reactive oxygen species and metal ion metabolism, and epithelial cell proliferation. In addition, KEGG enrichment analysis indicated that the signaling pathways were notably enriched in lipid and atherosclerosis, fluid shear stress and atherosclerosis, IL-17 signaling pathway, EGFR tyrosine kinase inhibitor resistance, PI3K-Akt signaling pathway, and TNF signaling pathway. Moreover, the molecular docking manifested excellent binding capacity between the active ingredients and targets on AP.

CONCLUSION

This study comprehensively illustrated the bioactive, potential targets, and molecular mechanisms of CDDP against AP, offering fresh perspectives into the molecular mechanisms of CDDP in preventing and treating AP.

Coronary Microvascular Dysfunction in Asymptomatic Patients with Severe Psoriasis

Severe psoriasis is associated with an increased cardiovascular risk, which may be independent of the traditional risk factors. Coronary microvascular dysfunction (CMD) has been shown to predict a poor cardiovascular prognosis in the general population and in patients with psoriasis. In this study, we assessed the prevalence and predictors of CMD in a large cohort of patients with psoriasis without clinical cardiovascular disease. A total of 503 patients with psoriasis were enrolled and underwent transthoracic Doppler echocardiography to evaluate coronary microcirculation. Of these, 55 patients were excluded from the analyses because of missing data. Of the 448 patients in this study, 31.5% showed CMD. Higher PASI, longer disease duration, the presence of psoriatic arthritis, and hypertension were independently associated with CMD. An increase of 1 point of PASI and 1 year of psoriasis duration were associated with a 5.8% and 4.6% increased risk of CMD, respectively. In our study, CMD was associated with the severity and duration of psoriasis. This supports the role of systemic inflammation in CMD and suggests that the coronary microcirculation may represent an extracutaneous site involved in the immune-mediated injury of psoriasis. We should diagnose and actively search for CMD in patients with severe psoriasis.

COVID-19 and cardiovascular complications: updates of emergency medicine

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and SARS-CoV-2 variants, has become a global pandemic resulting in significant morbidity and mortality. Severe cases of COVID-19 are characterized by hypoxemia, hyper-inflammation, cytokine storm in lung. Clinical studies have reported an association between COVID-19 and cardiovascular disease (CVD). Patients with CVD tend to develop severe symptoms and mortality if contracted COVID-19 with further elevations of cardiac injury biomarkers. Furthermore, COVID-19 itself can induce and promoted CVD development, including myocarditis, arrhythmia, acute coronary syndrome, cardiogenic shock, and venous thromboembolism. Although the direct etiology of SARS-CoV-2 induced cardiac injury remains unknown and under-investigated, it is suspected that it is related to myocarditis, cytokine-mediated injury, microvascular injury, and stress-related cardiomyopathy. Despite vaccinations having provided the most effective approach to reducing mortality overall, an adapted treatment paradigm and regular monitoring of cardiac injury biomarkers is critical for improving outcomes in vulnerable populations at risk for severe COVID-19. In this review, we focus on the latest progress in clinic and research on the cardiovascular complications of COVID-19 and provide a perspective of treating cardiac complications deriving from COVID-19 in Emergency Medicine.

Chronic remote ischemic conditioning treatment in patients with chronic stable angina (EARLY-MYO-CSA): a randomized, controlled proof-of-concept trial

BACKGROUND

Chronic remote ischemic conditioning (CRIC) has been shown to improve myocardial ischemia in experimental animal studies; however, its effectiveness in patients with chronic stable angina (CSA) has not been investigated. We conducted a proof-of-concept study to investigate the efficacy and safety of a six-month CRIC treatment in patients with CSA.

METHODS

The EARLY-MYO-CSA trial was a prospective, randomized, controlled trial evaluating the CRIC treatment in patients with CSA with persistent angina pectoris despite receiving ≥ 3-month guideline-recommended optimal medical therapy. The CRIC and control groups received CRIC (at 200 mmHg) or sham CRIC (at 60 mmHg) intervention for 6 months, respectively. The primary endpoint was the 6-month change of myocardial flow reserve (MFR) on single-photon emission computed tomography. The secondary endpoints were changes in rest and stress myocardial blood flow (MBF), angina severity according to the Canadian Cardiovascular Society (CCS) classification, the Seattle Angina Questionnaire (SAQ), and a 6-min walk test (6-MWT).

RESULTS

Among 220 randomized CSA patients, 208 (105 in the CRIC group, and 103 in the control group) completed the treatment and endpoint assessments. The mean change in MFR was significantly greater in the CRIC group than in the control group (0.27 ± 0.38 vs. - 0.04 ± 0.25; P < 0.001). MFR increased from 1.33 ± 0.48 at baseline to 1.61 ± 0.53 (P < 0.001) in the CRIC group; however, a similar increase was not seen in the control group (1.35 ± 0.45 at baseline and 1.31 ± 0.44 at follow-up, P = 0.757). CRIC treatment, when compared with controls, demonstrated improvements in angina symptoms assessed by CCS classification (60.0% vs. 14.6%, P < 0.001), all SAQ dimensions scores (P < 0.001), and 6-MWT distances (440 [400-523] vs. 420 [330-475] m, P = 0.016). The incidence of major adverse cardiovascular events was similar between the groups.

CONCLUSIONS

CSA patients benefit from 6-month CRIC treatment with improvements in MFR, angina symptoms, and exercise performance. This treatment is well-tolerated and can be recommended for symptom relief in this clinical population.

TRIAL REGISTRATION

[chictr.org.cn], identifier [ChiCTR2000038649].

Coronary microvascular disease: The "Meeting Point" of Cardiology, Rheumatology and Endocrinology

BACKGROUND

Exertional chest pain/dyspnea or chest pain at rest are the main symptoms of coronary artery disease (CAD), which are traditionally attributed to insufficiency of the epicardial coronary arteries. However, 2/3 of women and 1/3 of men with angina and 10% of patients with acute myocardial infarction have no evidence of epicardial coronary artery stenosis in X-ray coronary angiography. In these cases, coronary microvascular disease (CMD) is the main causative factor.

AIMS

To present the pathophysiology of CMD in Cardiology, Rheumatology and Endocrinology.

MATERIALS-METHODS

The pathophysiology of CMD in Cardiology, Rheumatology and Endocrinology was evaluated. It includes impaired microvascular vasodilatation, which leads to inability of the organism to deal with myocardial oxygen needs and, hence, development of ischemic pain. CMD, observed in inflammatory autoimmune rheumatic and endocrine/metabolic disorders, brings together Cardiology, Rheumatology and Endocrinology. Causative factors include persistent systemic inflammation and endocrine/metabolic abnormalities influencing directly the coronary microvasculature. In the past, the evaluation of microcirculation was feasible only with the use of invasive techniques, such as coronary flow reserve assessment. Currently, the application of advanced imaging modalities, such as cardiovascular magnetic resonance (CMR), can evaluate CMD non-invasively and without ionizing radiation.

RESULTS

CMD may present with a variety of symptoms with 1/3 to 2/3 of them expressed as typical chest pain in effort, more commonly found in women during menopause than in men. Atypical presentation includes chest pain at rest or exertional dyspnea,but post exercise symptoms are not uncommon. The treatment with nitrates is less effective in CMD, because their vasodilator action in coronary micro-circulation is less pronounced than in the epicardial coronary arteries.

DISCUSSION

Although both classic and new medications have been used in the treatment of CMD, there are still many questions regarding both the pathophysiology and the treatment of this disorder. The potential effects of anti-rheumatic and endocrine medications on the evolution of CMD need further evaluation.

CONCLUSION

CMD is a multifactorial disease leading to myocardial ischemia/fibrosis alone or in combination with epicardial coronary artery disease. Endothelial dysfunction/vasospasm, systemic inflammation, and/or neuroendocrine activation may act as causative factors and bring Cardiology, Rheumatology and Endocrinology together. Currently, the application of advanced imaging modalities, and specifically CMR, allows reliable assessment of the extent and severity of CMD. These measurements should not be limited to "pure cardiac patients", as it is known that CMD affects the majority of patients with autoimmune rheumatic and endocrine/metabolic disorders.

Renin Angiotensin Blockers and Cardiac Protection: From Basis to Clinical Trials

Despite a similar beneficial effect on blood pressure lowering observed with angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II type 1 receptor (AT1R) blocker (ARBs), several clinical trials and meta-analyses have reported higher cardiovascular mortality and lower protection against myocardial infarction with ARBs when compared with ACEIs. The European guidelines for the management of coronary syndromes and European guidelines on diabetes recommend using ARBs in patients who are intolerant to ACEIs. We reviewed the main pharmacological differences between ACEIs and ARBs, which could provide insights into the differences in the cardiac protection offered by these 2 drug classes. The effect of ACEIs on the tissue and plasma levels of bradykinin and on nitric oxide production and bioavailability is specific to the mechanism of action of ACEIs; it could account for the different effects of ACEIs and ARBs on endothelial function, atherogenesis, and fibrinolysis. Moreover, chronic blockade of AT1 receptors by ARBs induces a significant and permanent increase in plasma angiotensin II and an overstimulation of its still available receptors. In animal models, AT4 receptors have vasoconstrictive, proliferative, and inflammatory effects. Moreover, in models with kidney damage, atherosclerosis, and/or senescence, activation of AT2 receptors could have deleterious fibrotic, vasoconstrictive, and hypertrophic effects and seems prudent and reasonable to reserve the use of ARBs for patients who have presented intolerance to ACE inhibitors.

Myocardial oedema: pathophysiological basis and implications for the failing heart

Myocardial fluid homeostasis relies on a complex interplay between microvascular filtration, interstitial hydration, cardiomyocyte water uptake and lymphatic removal. Dysregulation of one or more of these mechanisms may result in myocardial oedema. Interstitial and intracellular fluid accumulation disrupts myocardial architecture, intercellular communication, and metabolic pathways, decreasing contractility and increasing myocardial stiffness. The widespread use of cardiac magnetic resonance enabled the identification of myocardial oedema as a clinically relevant imaging finding with prognostic implications in several types of heart failure. Furthermore, growing experimental evidence has contributed to a better understanding of the physical and molecular interactions in the microvascular barrier, myocardial interstitium and lymphatics and how they might be disrupted in heart failure. In this review, we summarize current knowledge on the factors controlling myocardial water balance in the healthy and failing heart and pinpoint the new potential therapeutic avenues.

Noble Gases Therapy in Cardiocerebrovascular Diseases: The Novel Stars?

Cardiocerebrovascular diseases (CCVDs) are the leading cause of death worldwide; therefore, to deeply explore the pathogenesis of CCVDs and to find the cheap and efficient strategies to prevent and treat CCVDs, these are of great clinical and social significance. The discovery of nitric oxide (NO), as one of the endothelium-derived relaxing factors and its successful utilization in clinical practice for CCVDs, provides new ideas for us to develop drugs for CCVDs: “gas medicine” or “medical gases.” The endogenous gas molecules such as carbon monoxide (CO), hydrogen sulfide (H₂S), sulfur dioxide (SO₂), methane (CH₄), and hydrogen (H₂) have essential biological effects on modulating cardiocerebrovascular homeostasis and CCVDs. Moreover, it has been shown that noble gas atoms such as helium (He), neon (Ne), argon (Ar), krypton (Kr), and xenon (Xe) display strong cytoprotective effects and therefore, act as the exogenous pharmacologic preventive and therapeutic agents for CCVDs. Mechanistically, besides the competitive inhibition of N-methyl-D-aspartate (NMDA) receptor in nervous system by xenon, the key and common mechanisms of noble gases are involved in modulation of cell death and inflammatory or immune signals. Moreover, gases interaction and reduction in oxidative stress are emerging as the novel biological mechanisms of noble gases. Therefore, to investigate the precise actions of noble gases on redox signals, gases interaction, different cell death forms, and the emerging field of gasoimmunology, which focus on the effects of gas atoms/molecules on innate immune signaling or immune cells under both the homeostatic and perturbed conditions, these will help us to uncover the mystery of noble gases in modulating CCVDs.

The Role of Ivabradine in Managing Symptomatic Patients with Chronic Coronary Syndromes: A Clinically Oriented Approach

Angina is a significant contributor to disability and impairment in quality of life in patients with chronic coronary syndromes (CCS). An elevated heart rate (HR) may trigger myocardial ischemia by increasing oxygen consumption and decreasing the diastolic time, compromising the coronary flow. HR-lowering strategies offer symptom control and prevent cardiovascular events in subgroups of patients with CCS. However, the best therapeutic approach to achieve the desired HR in patients with CCS can be challenging based on efficacy and tolerability. Guidelines usually propose β-blockers and/or non-dihydropyridine calcium channel blockers (CCB) for angina patients with elevated HR. Nonetheless, there is no clear evidence of greater antianginal efficacy of this strategy versus an alternative HR-lowering agent. Ivabradine reduces the HR by blocking the I_f current in the sinoatrial node without affecting myocardial contractility or vascular tone. The magnitude of the HR reduction by ivabradine is proportional to the initial HR, which decreases the risk of significant bradycardia. Ivabradine increases the diastolic time and the coronary flow reserve to a greater extent than β-blockers and favors collateralization, improving the regional blood flow. We present two clinical cases of patients with symptomatic CCS in whom HR control with ivabradine was fundamental for symptom control and improvement in left ventricular (LV) function. An earlier combination of ivabradine plus β-blockers would have provided more rapid symptom control and improved LV function in the first case. In the second case, the primary mechanism responsible for angina was most likely a coronary vasomotor abnormality, in which the use of β-blockers aggravated the discomfort. The combination of a dihydropyridine CCB plus ivabradine was highly influential in symptom control. Due to its effects beyond HR reduction and good tolerability, ivabradine should be considered an essential ally in managing patients with angina and high HR with or without LV dysfunction.

A pathophysiological compass to personalize antianginal drug treatment

Myocardial ischaemia results from coronary macrovascular or microvascular dysfunction compromising the supply of oxygen and nutrients to the myocardium. The underlying pathophysiological processes are manifold and encompass atherosclerosis of epicardial coronary arteries, vasospasm of large or small vessels and microvascular dysfunction - the clinical relevance of which is increasingly being appreciated. Myocardial ischaemia can have a broad spectrum of clinical manifestations, together denoted as chronic coronary syndromes. The most common antianginal medications relieve symptoms by eliciting coronary vasodilatation and modulating the determinants of myocardial oxygen consumption, that is, heart rate, myocardial wall stress and ventricular contractility. In addition, cardiac substrate metabolism can be altered to alleviate ischaemia by modulating the efficiency of myocardial oxygen use. Although a universal agreement exists on the prognostic importance of lifestyle interventions and event prevention with aspirin and statin therapy, the optimal antianginal treatment for patients with chronic coronary syndromes is less well defined. The 2019 guidelines of the ESC recommend a personalized approach, in which antianginal medications are tailored towards an individual patient's comorbidities and haemodynamic profile. Although no antianginal medication improves survival, their efficacy for reducing symptoms profoundly depends on the underlying mechanism of the angina. In this Review, we provide clinicians with a rationale for when to use which compound or combination of drugs on the basis of the pathophysiology of the angina and the mode of action of antianginal medications.

Comparing invasive hemodynamic responses in adenosine hyperemia versus physical exercise stress in chronic coronary syndromes

OBJECTIVES

Adenosine hyperemia is an integral component of the physiological assessment of obstructive coronary artery disease in patients with chronic coronary syndrome (CCS). The aim of this study was to compare systemic, coronary and microcirculatory hemodynamics between intravenous (IV) adenosine hyperemia versus physical exercise stress in patients with CCS and coronary stenosis.

METHODS

Twenty-three patients (mean age, 60.6 ± 8.1 years) with CCS and single-vessel coronary stenosis underwent cardiac catheterization. Continuous trans-stenotic coronary pressure-flow measurements were performed during: i) IV adenosine hyperemia, and ii) physical exercise using a catheter-table-mounted supine ergometer. Systemic, coronary and microcirculatory hemodynamic responses were compared between IV adenosine and exercise stimuli.

RESULTS

Mean stenosis diameter was 74.6% ± 10.4. Median (interquartile range) FFR was 0.54 (0.44-0.72). At adenosine hyperemia versus exercise stress, mean aortic pressure (Pa, 91 ± 16 mmHg vs 99 ± 15 mmHg, p < 0.0001), distal coronary pressure (Pd, 58 ± 21 mmHg vs 69 ± 24 mmHg, p < 0.0001), trans-stenotic pressure ratio (Pd/Pa, 0.63 ± 0.18 vs 0.69 ± 0.19, p < 0.0001), microvascular resistance (MR, 2.9 ± 2.2 mmHg.cm-1.sec-1 vs 4.2 ± 1.7 mmHg.cm-1.sec-1, p = 0.001), heart rate (HR, 80 ± 15 bpm vs 85 ± 21 bpm, p = 0.02) and rate-pressure product (RPP, 7522 ± 2335 vs 9077 ± 3200, p = 0.0001) were all lower. Conversely, coronary flow velocity (APV, 23.7 ± 9.5 cm/s vs 18.5 ± 6.8 cm/s, p = 0.02) was higher. Additionally, temporal changes in Pa, Pd, Pd/Pa, MR, HR, RPP and APV during IV adenosine hyperemia versus exercise were all significantly different (p < 0.05 for all).

CONCLUSIONS

In patients with CCS and coronary stenosis, invasive hemodynamic responses differed markedly between IV adenosine hyperemia versus physical exercise stress. These differences were observed across systemic, coronary and microcirculatory hemodynamics.

Arterial Hypertension and Diabetes Mellitus in COVID-19 Patients: What Is Known by Gender Differences?

BACKGROUND

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has infected >160 million people around the world. Hypertension (HT), chronic heart disease (CHD), and diabetes mellitus (DM) increase susceptibility to SARS-CoV-2 infection.

AIMS

We designed this retrospective study to assess the gender differences in hypertensive diabetic SARS-CoV-2 patients. We reported data, by gender differences, on the inflammatory status, on the hospital stays, intensive care unit (ICU) admission, Rx and CT report, and therapy.

METHODS

We enrolled 1014 patients with confirmed COVID-19 admitted into different Hospitals of Campania from 26 March to 30 June, 2020. All patients were allocated into two groups: diabetic-hypertensive group (DM-HT group) that includes 556 patients affected by diabetes mellitus and arterial hypertension and the non-diabetic- non-hypertensive group (non-DM, non-HT group) comprising 458 patients. The clinical outcomes (i.e., discharges, mortality, length of stay, therapy, and admission to intensive care) were monitored up to June 30, 2020.

RESULTS

We described, in the DM-HT group, higher proportion of cardiopathy ischemic (CHD) (47.5% vs. 14.8%, respectively; p < 0.0001) and lung diseases in females compared to male subjects (34.8% vs. 18.5%, respectively; p < 0.0001). In male subjects, we observed higher proportion of kidney diseases (CKD) (11% vs. 0.01%, respectively; p < 0.0001), a higher hospital stay compared to female subjects (22 days vs. 17 days, respectively, p < 0.0001), a higher admission in ICU (66.9% vs. 12.8%, respectively, p < 0.0001), and higher death rate (17.3% vs. 10.7%, respectively, p < 0.0001).

CONCLUSION

These data confirm that male subjects, compared to female subjects, have a higher hospital stay, a higher admission to ICU, and higher death rate.

ANMCO POSITION PAPER: cardio-oncology in the COVID era (CO and CO)

The COVID-19 pandemic and its impact on patients with cancer and cardiovascular disease have confirmed the particular vulnerability of these populations. Indeed, not only a higher risk of contracting the infection has been reported but also an increased occurrence of a more severe course and unfavourable outcome. Beyond the direct consequences of COVID-19 infection, the pandemic has an enormous impact on global health systems. Screening programmes and non-urgent tests have been postponed; clinical trials have suffered a setback. Similarly, in the area of cardiology care, a significant decline in STEMI accesses and an increase in cases of late presenting heart attacks with increased mortality and complication rates have been reported. Health care systems must therefore get ready to tackle the 'rebound effect' that will likely show a relative increase in the short- and medium-term incidence of diseases such as heart failure, myocardial infarction, arrhythmias, and cardio- and cerebrovascular complications. Scientific societies are taking action to provide general guidance and recommendations aimed at mitigating the unfavourable outcomes of this pandemic emergency. Cardio-oncology, as an emerging discipline, is more flexible in modulating care pathways and represents a beacon of innovation in the development of multi-specialty patient management. In the era of the COVID-19 pandemic, cardio-oncology has rapidly modified its clinical care pathways and implemented flexible monitoring protocols that include targeted use of cardiac imaging, increased use of biomarkers, and telemedicine systems. The goal of these strategic adjustments is to minimize the risk of infection for providers and patients while maintaining standards of care for the treatment of oncologic and cardiovascular diseases. The aim of this document is to evaluate the impact of the pandemic on the management of cardio-oncologic patients with the-state-of-the-art knowledge about severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and coronavirus disease (COVID-19) in order to optimize medical strategies during and after the pandemic.

What Is the Role of Assessing Ischemia to Optimize Therapy and Outcomes for Patients with Stable Angina and Non-obstructed Coronary Arteries?

Ischemic heart disease (IHD) is a leading global cause of ill-health and premature death. Clinical research into IHD is providing new insights into the pathophysiology, epidemiology and treatment of this condition. The major endotypes of IHD include coronary heart disease (CHD) and vasomotor disorders, including microvascular angina and vasospastic angina. Considering unselected patients presenting with stable chest pain, the pre-test probability of CHD is higher in men whereas the pre-test probability of a vasomotor disorder is higher in women. The diagnostic accuracy of diagnostic tests designed to assess coronary anatomy and disease and/or coronary vascular function (functional tests) differ for coronary endotypes. Clinical management should therefore be personalized and take account of sex-related factors. In this review, we consider the definitions of angina and myocardial ischemia. We then appraise the mechanistic links between myocardial ischemia and anginal symptoms and the relative merits of non-invasive and invasive diagnostic tests and related clinical management. Finally, we describe the rationale and importance of stratified medicine of IHD.

Resting global myocardial work can improve interpretation of exercise stress echocardiography

Sensitivity and specificity of ESE to determine hemodynamically significant coronary artery disease (CAD) is limited by subjective qualitative interpretation resulting in false-positive results. The objective of this study was to determine whether resting myocardial work estimated from non-invasive left ventricular pressure-strain loops can help improve the interpretation of exercise stress echocardiography (ESE). Resting global myocardial work was performed on 288 patients referred for clinically indicated ESE with no resting regional wall motion abnormalities and normal ejection fraction (≥ 55%). Coronary angiography was used to validate the presence of significant CAD in those with a positive ESE. Resting global myocardial work index (GWI) was significantly reduced (p < 0.001) in patients with true-positive (1544 ± 354 mmHg%) compared to negative (1819 ± 317 mmHg%) and false-positive (1857 ± 344 mmHg%) ESE. A GWI of ≤ 1391 mmHg (AUC 0.73; sensitivity 94%; specificity 73%) predicted true-positive ESE. Predictors of a true-positive ESE were (1) lower myocardial work efficiency (odds ratio 0.731, 95% CI 0.58-0.92, p = 0.007), (2) lower GWI (odds ratio 0.997, 95% CI 0.996-0.999, p = 0.006) (3) male gender (odds ratio 5.47, 95% CI 1.84-16.31, p = 0.002) and (4) E/e' ratio (odds ratio 1.15, CI 1.01-1.31, p = 0.032). Myocardial work is a potentially valuable quantitative parameter that provides incremental value over qualitative ESE interpretation and improves appropriate patient selection for coronary angiography.

Impairment of platelet NO signalling in coronary artery spasm: role of hydrogen sulphide

BACKGROUND AND PURPOSE

The pathophysiology of coronary artery spasm (CAS), with its associated ischaemic crises, is currently poorly understood and treatment is frequently ineffective. In view of increasing evidence that platelet-based defects may occur in CAS patients, we investigated platelet reactivity in CAS patients and whether symptomatic crises reflect activation of platelet-endothelial interactions.

EXPERIMENTAL APPROACH

CAS patients were evaluated during acute and/or chronic symptomatic phases and compared with healthy control subjects. Inhibition of ADP-induced platelet aggregation by the NO donor sodium nitroprusside (SNP) and plasma concentrations of syndecan 1 (glycocalyx shedding marker), tryptase (mast cell activation marker) and platelet microparticles were measured.

KEY RESULTS

Inhibition of platelet aggregation by SNP was diminished in chronic CAS, with further (non-significant) deterioration during symptomatic crises, whereas plasma concentrations of syndecan 1, tryptase and platelet microparticles increased. Treatment of patients with high-dose N-acetylcysteine (NAC) plus glyceryl trinitrate rapidly increased platelet responsiveness to SNP and decreased plasma syndecan 1 concentrations. The effect of NAC on platelet responsiveness to SNP was confirmed in vitro and mimicked by the H₂ S donor NaHS. Conversely, inhibition of enzymatic production of H₂ S attenuated NAC effect.

CONCLUSION AND IMPLICATIONS

CAS is associated with substantial impairment of platelet NO signalling. During acute symptomatic exacerbations, platelet resistance to NO is aggravated, together with mast cell activation and damage to both vasculature and platelets. NAC, via release of H₂ S, reverses platelet resistance to NO and terminates glycocalyx shedding during symptomatic crises: This suggests that H₂ S donors may correct the pathophysiological anomalies underlying CAS.

ESC Working Group on Coronary Pathophysiology and Microcirculation position paper on 'coronary microvascular dysfunction in cardiovascular disease'

Although myocardial ischaemia usually manifests as a consequence of atherosclerosis-dependent obstructive epicardial coronary artery disease, a significant percentage of patients suffer ischaemic events in the absence of epicardial coronary artery obstruction. Experimental and clinical evidence highlight the abnormalities of the coronary microcirculation as a main cause of myocardial ischaemia in patients with 'normal or near normal' coronary arteries on angiography. Coronary microvascular disturbances have been associated with early stages of atherosclerosis even prior to any angiographic evidence of epicardial coronary stenosis, as well as to other cardiac pathologies such as myocardial hypertrophy and heart failure. The main objectives of the manuscript are (i) to provide updated evidence in our current understanding of the pathophysiological consequences of microvascular dysfunction in the heart; (ii) to report on the current knowledge on the relevance of cardiovascular risk factors and comorbid conditions for microcirculatory dysfunction; and (iii) to evidence the relevance of the clinical consequences of microvascular dysfunction. Highlighting the clinical importance of coronary microvascular dysfunction will open the field for research and the development of novel strategies for intervention will encourage early detection of subclinical disease and will help in the stratification of cardiovascular risk in agreement with the new concept of precision medicine.

Coronary Microvascular Dysfunction

Many patients with chest pain undergoing coronary angiography do not show significant obstructive coronary lesions. A substantial proportion of these patients have abnormalities in the function and structure of coronary microcirculation due to endothelial and smooth muscle cell dysfunction. The coronary microcirculation has a fundamental role in the regulation of coronary blood flow in response to cardiac oxygen requirements. Impairment of this mechanism, defined as coronary microvascular dysfunction (CMD), carries an increased risk of adverse cardiovascular clinical outcomes. Coronary endothelial dysfunction accounts for approximately two-thirds of clinical conditions presenting with symptoms and signs of myocardial ischemia without obstructive coronary disease, termed "ischemia with non-obstructive coronary artery disease" (INOCA) and for a small proportion of "myocardial infarction with non-obstructive coronary artery disease" (MINOCA). More frequently, the clinical presentation of INOCA is microvascular angina due to CMD, while some patients present vasospastic angina due to epicardial spasm, and mixed epicardial and microvascular forms. CMD may be associated with focal and diffuse epicardial coronary atherosclerosis, which may reinforce each other. Both INOCA and MINOCA are more common in females. Clinical classification of CMD includes the association with conditions in which atherosclerosis has limited relevance, with non-obstructive atherosclerosis, and with obstructive atherosclerosis. Several studies already exist which support the evidence that CMD is part of systemic microvascular disease involving multiple organs, such as brain and kidney. Moreover, CMD is strongly associated with the development of heart failure with preserved ejection fraction (HFpEF), diabetes, hypertensive heart disease, and also chronic inflammatory and autoimmune diseases. Since coronary microcirculation is not visible on invasive angiography or computed tomographic coronary angiography (CTCA), the diagnosis of CMD is usually based on functional assessment of microcirculation, which can be performed by both invasive and non-invasive methods, including the assessment of delayed flow of contrast during angiography, measurement of coronary flow reserve (CFR) and index of microvascular resistance (IMR), evaluation of angina induced by intracoronary acetylcholine infusion, and assessment of myocardial perfusion by positron emission tomography (PET) and magnetic resonance (CMR).

Recent updates on novel therapeutic targets of cardiovascular diseases

In recent times cardiovascular diseases (CVDs) are the leading cause of mortality universally, caused more or less 17.7 million casualties with 45% of all illnesses (except communicable ones) in 2015 as per World Health Organization (WHO). According to American National Center for Health Statistics, cardiac disorders are costliest. Moreover, health care expenditures related to cardiac disorders are anticipated to exceed than diabetes and Alzheimer's. Straining of reactive oxygen species with diminished neutralization & inflammation critically adds to atherosclerosis and also proceed to other cardiovascular diseases such as cardiac remodeling and myocardial infarction (MI). In the past few years, researchers revealed multiple drug targets from animal studies and evaluated them in the therapeutics of cardiac disorders, which offered exciting clues for novel therapeutic strategies. Although, only few newer agents approved clinically and actual approaches for treatment are lagging behind. Several novel drugs found effective for the treatment of hypertension, congestive heart failure, cardiac arrhythmia and angina pectoris. Detailed mechanism of action, basic and clinical pharmacology of all novel drugs has been discussed in this review.

COVID-19 and the cardiovascular system: implications for risk assessment, diagnosis, and treatment options

The novel coronavirus disease (COVID-19) outbreak, caused by SARS-CoV-2, represents the greatest medical challenge in decades. We provide a comprehensive review of the clinical course of COVID-19, its comorbidities, and mechanistic considerations for future therapies. While COVID-19 primarily affects the lungs, causing interstitial pneumonitis and severe acute respiratory distress syndrome (ARDS), it also affects multiple organs, particularly the cardiovascular system. Risk of severe infection and mortality increase with advancing age and male sex. Mortality is increased by comorbidities: cardiovascular disease, hypertension, diabetes, chronic pulmonary disease, and cancer. The most common complications include arrhythmia (atrial fibrillation, ventricular tachyarrhythmia, and ventricular fibrillation), cardiac injury [elevated highly sensitive troponin I (hs-cTnI) and creatine kinase (CK) levels], fulminant myocarditis, heart failure, pulmonary embolism, and disseminated intravascular coagulation (DIC). Mechanistically, SARS-CoV-2, following proteolytic cleavage of its S protein by a serine protease, binds to the transmembrane angiotensin-converting enzyme 2 (ACE2) -a homologue of ACE-to enter type 2 pneumocytes, macrophages, perivascular pericytes, and cardiomyocytes. This may lead to myocardial dysfunction and damage, endothelial dysfunction, microvascular dysfunction, plaque instability, and myocardial infarction (MI). While ACE2 is essential for viral invasion, there is no evidence that ACE inhibitors or angiotensin receptor blockers (ARBs) worsen prognosis. Hence, patients should not discontinue their use. Moreover, renin-angiotensin-aldosterone system (RAAS) inhibitors might be beneficial in COVID-19. Initial immune and inflammatory responses induce a severe cytokine storm [interleukin (IL)-6, IL-7, IL-22, IL-17, etc.] during the rapid progression phase of COVID-19. Early evaluation and continued monitoring of cardiac damage (cTnI and NT-proBNP) and coagulation (D-dimer) after hospitalization may identify patients with cardiac injury and predict COVID-19 complications. Preventive measures (social distancing and social isolation) also increase cardiovascular risk. Cardiovascular considerations of therapies currently used, including remdesivir, chloroquine, hydroxychloroquine, tocilizumab, ribavirin, interferons, and lopinavir/ritonavir, as well as experimental therapies, such as human recombinant ACE2 (rhACE2), are discussed.

Microvascular and lymphatic dysfunction in HFpEF and its associated comorbidities

Heart failure with preserved ejection fraction (HFpEF) is a complex heterogeneous disease for which our pathophysiological understanding is still limited and specific prevention and treatment strategies are lacking. HFpEF is characterised by diastolic dysfunction and cardiac remodelling (fibrosis, inflammation, and hypertrophy). Recently, microvascular dysfunction and chronic low-grade inflammation have been proposed to participate in HFpEF development. Furthermore, several recent studies demonstrated the occurrence of generalized lymphatic dysfunction in experimental models of risk factors for HFpEF, including obesity, hypercholesterolaemia, type 2 diabetes mellitus (T2DM), hypertension, and aging. Here, we review the evidence for a combined role of coronary (micro)vascular dysfunction and lymphatic vessel alterations in mediating key pathological steps in HFpEF, including reduced cardiac perfusion, chronic low-grade inflammation, and myocardial oedema, and their impact on cardiac metabolic alterations (oxygen and nutrient supply/demand imbalance), fibrosis, and cardiomyocyte stiffness. We focus primarily on HFpEF caused by metabolic risk factors, such as obesity, T2DM, hypertension, and aging.

Perturbations in myocardial perfusion and oxygen balance in swine with multiple risk factors: a novel model of ischemia and no obstructive coronary artery disease

Comorbidities of ischemic heart disease, including diabetes mellitus (DM), hypercholesterolemia (HC) and chronic kidney disease (CKD), are associated with coronary microvascular dysfunction (CMD). Increasing evidence suggests that CMD may contribute to myocardial ‘Ischemia and No Obstructive Coronary Artery disease’ (INOCA). In the present study, we tested the hypothesis that CMD results in perturbations in myocardial perfusion and oxygen delivery using a novel swine model with multiple comorbidities. DM (streptozotocin), HC (high-fat diet) and CKD (renal embolization) were induced in 10 female swine (DM + HC + CKD), while 12 healthy female swine on a normal diet served as controls (Normal). After 5 months, at a time when coronary atherosclerosis was still negligible, myocardial perfusion, metabolism, and function were studied at rest and during treadmill exercise. DM + HC + CKD animals showed hyperglycemia, hypercholesterolemia, and impaired kidney function. During exercise, DM + HC + CKD swine demonstrated perturbations in myocardial blood flow and oxygen delivery, necessitating a higher myocardial oxygen extraction—achieved despite reduced capillary density—resulting in lower coronary venous oxygen levels. Moreover, myocardial efficiency was lower, requiring higher oxygen consumption for a given level of myocardial work. These perturbations in myocardial oxygen balance were associated with lower myocardial lactate consumption, stroke volume, and LVdP/dt_max, suggestive of myocardial ischemia and dysfunction. Further analyses showed a reduction in adenosine-recruitable coronary flow reserve, but this was exclusively the result of an increase in basal coronary blood flow, while maximal coronary flow per gram of myocardium was maintained; the latter was consistent with the unchanged arteriolar wall/lumen ratio, arteriolar density and peri-arteriolar collagen content. However, isolated small arteries displayed selective blunting of endothelium-dependent vasodilation in response to bradykinin in DM + HC + CKD swine, suggesting that changes in coronary microvascular function rather than in structure contributed to the perturbations in myocardial oxygen delivery. In conclusion, common comorbidities in swine result in CMD, in the absence of appreciable atherosclerosis, which is severe enough to produce perturbations in myocardial oxygen balance, particularly during exercise, resembling key features of INOCA.