Myocardial Ischemic Syndromes: A New Nomenclature to Harmonize Evolving International Clinical Practice Guidelines.

Since the 1960s, cardiologists have adopted several binary classification systems for acute myocardial infarction (MI) that facilitated improved patient management. Conversely, for chronic stable manifestations of myocardial ischemia, various classifications have emerged over time, often with conflicting terminology-eg, "stable coronary artery disease" (CAD), "stable ischemic heart disease," and "chronic coronary syndromes" (CCS). While the 2019 European guidelines introduced CCS to impart symmetry with "acute coronary syndromes" (ACS), the 2023 American guidelines endorsed the alternative term "chronic coronary disease." An unintended consequence of these competing classifications is perpetuation of the restrictive terms "coronary" and 'disease', often connoting only a singular obstructive CAD mechanism. It is now important to advance a more broadly inclusive terminology for both obstructive and non-obstructive causes of angina and myocardial ischemia that fosters conceptual clarity and unifies dyssynchronous nomenclatures across guidelines. We, therefore, propose a new binary classification of "acute myocardial ischemic syndromes" and "non-acute myocardial ischemic syndromes," which comprises both obstructive epicardial and non-obstructive pathogenetic mechanisms, including microvascular dysfunction, vasospastic disorders, and non-coronary causes. We herein retain accepted categories of ACS, ST-segment elevation MI, and non-ST segment elevation MI, as important subsets for which revascularization is of proven clinical benefit, as well as new terms like ischemia and MI with non-obstructive coronary arteries. Overall, such a more encompassing nomenclature better aligns, unifies, and harmonizes different pathophysiologic causes of myocardial ischemia and should result in more refined diagnostic and therapeutic approaches targeted to the multiple pathobiological precipitants of angina pectoris, ischemia, and infarction.

Myocardial ischaemic syndromes: a new nomenclature to harmonize evolving international clinical practice guidelines.

Since the 1960s, cardiologists have adopted several binary classification systems for acute myocardial infarction (MI) that facilitated improved patient management. Conversely, for chronic stable manifestations of myocardial ischaemia, various classifications have emerged over time, often with conflicting terminology-e.g. 'stable coronary artery disease' (CAD), 'stable ischaemic heart disease', and 'chronic coronary syndromes' (CCS). While the 2019 European guidelines introduced CCS to impart symmetry with 'acute coronary syndromes' (ACS), the 2023 American guidelines endorsed the alternative term 'chronic coronary disease'. An unintended consequence of these competing classifications is perpetuation of the restrictive terms 'coronary' and 'disease', often connoting only a singular obstructive CAD mechanism. It is now important to advance a more broadly inclusive terminology for both obstructive and non-obstructive causes of angina and myocardial ischaemia that fosters conceptual clarity and unifies dyssynchronous nomenclatures across guidelines. We, therefore, propose a new binary classification of 'acute myocardial ischaemic syndromes' and 'non-acute myocardial ischaemic syndromes', which comprises both obstructive epicardial and non-obstructive pathogenetic mechanisms, including microvascular dysfunction, vasospastic disorders, and non-coronary causes. We herein retain accepted categories of ACS, ST-segment elevation MI, and non-ST-segment elevation MI, as important subsets for which revascularization is of proven clinical benefit, as well as new terms like ischaemia and MI with non-obstructive coronary arteries. Overall, such a more encompassing nomenclature better aligns, unifies, and harmonizes different pathophysiologic causes of myocardial ischaemia and should result in more refined diagnostic and therapeutic approaches targeted to the multiple pathobiological precipitants of angina pectoris, ischaemia and infarction.

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.

Anti-anginal drugs-beliefs and evidence: systematic review covering 50 years of medical treatment.

Chronic stable angina is the most prevalent symptom of ischaemic heart disease and its management is a priority. Current guidelines recommend pharmacological therapy with drugs classified as being first line (beta blockers, calcium channel blockers, short acting nitrates) or second line (long-acting nitrates, ivabradine, nicorandil, ranolazine, and trimetazidine). Second line drugs are indicated for patients who have contraindications to first line agents, do not tolerate them or remain symptomatic. Evidence that one drug is superior to another has been questioned. Between January and March 2018, we performed a systematic review of articles written in English over the past 50 years English-written articles in Medline and Embase following preferred reporting items and the Cochrane collaboration approach. We included double blind randomized studies comparing parallel groups on treatment of angina in patients with stable coronary artery disease, with a sample size of, at least, 100 patients (50 patients per group), with a minimum follow-up of 1 week and an outcome measured on exercise testing, duration of exercise being the preferred outcome. Thirteen studies fulfilled our criteria. Nine studies involved between 100 and 300 patients, (2818 in total) and a further four enrolled greater than 300 patients. Evidence of equivalence was demonstrated for the use of beta-blockers (atenolol), calcium antagonists (amlodipine, nifedipine), and channel inhibitor (ivabradine) in three of these studies. Taken all together, in none of the studies was there evidence that one drug was superior to another in the treatment of angina or to prolong total exercise duration. There is a paucity of data comparing the efficacy of anti-anginal agents. The little available evidence shows that no anti-anginal drug is superior to another and equivalence has been shown only for three classes of drugs. Guidelines draw conclusions not from evidence but from clinical beliefs.

A randomized, double-blind, placebo-controlled trial to assess the efficAcy and safety of Trimetazidine in patients with angina pectoris having been treated by percutaneous coronary intervention (ATPCI study): Rationale, design, and baseline characteristics.

BACKGROUND: About 30% of angina patients have persisting symptoms despite successful revascularization and antianginal therapy. Moreover, in stable patients, percutaneous coronary intervention (PCI) does not improve survival as compared with medical therapy alone. Trimetazidine, an antianginal agent devoid of hemodynamic effect, may help reducing symptoms and improving outcomes after PCI. The ATPCI study is investigating the efficacy and safety of adding trimetazidine to standard-of-care in angina patients who had a recent PCI. METHODS: ATPCI is a randomized, double-blind, parallel-group, placebo-controlled, event-driven study in patients with coronary artery disease having undergone PCI because of stable angina (elective PCI) or unstable angina/NSTEMI (urgent PCI). After PCI, patients were randomized to trimetazidine (35 mg bid) or placebo on top of standard-of-care including event prevention drugs and antianginal treatment. Patients will be followed for 2 to 4 years. The primary efficacy endpoint is a composite of cardiac death, hospitalization for a cardiac event and recurrence or persistence of angina. Safety events related to trimetazidine use will be monitored. RESULTS: Recruitment lasted from September 2014 to June 2016. A total of 6007 patients were enrolled (58% and 42% after elective and urgent PCI, respectively). Mean age was 61 years, 77% were males, and median durations of coronary artery disease were 1 and 5 months (if urgent or elective PCI, respectively). Almost all patients received drugs for event prevention and antianginal therapy at baseline. CONCLUSION: The ATPCI study will shed further light on the management of contemporary angina patients after PCI. Results are expected in 2019.

Determinants of long-term clinical outcomes in patients with angina but without obstructive coronary artery disease: a systematic review and meta-analysis.

Aims: The long-term prognosis of angina in patients without obstructive coronary artery disease (CAD) is uncertain. To assess the incidence of long-term adverse outcomes in such patients. Methods and results: We searched PubMed, Cochrane Library, the Embase database, and the Clinical Trials Registry for studies published in English until January 2017, assessing the composite primary outcome of all-cause death and non-fatal myocardial infarction using random-effects models to estimate pooled incidences. We identified 54 studies, reporting outcomes in overall 35 039 patients (mean age 56, male/female ratio 0.51, 99 770 person-years) with angina and no obstructive CAD. After a median follow-up of 5 years (interquartile range 3-7 years), the pooled incidence of the primary outcome was 0.98/100 person-years [95% confidence interval (CI) 0.77-1.19%], with considerable heterogeneity among studies (I2 = 91%, P < 0.001). The primary outcome was associated with prevalent dyslipidaemia (P = 0.016), diabetes (P = 0.035), and hypertension (P = 0.016). Studies enrolling patients with less-than-obstructive CAD showed a higher incidence of the primary outcome (1.32/100 person-years, 95% CI 1.02-1.62) compared with studies including only patients with 'entirely normal' coronary arteries (0.52/100 person-years, 95% CI 0.34-0.79, respectively; P < 0.01). The incidence of the primary outcome did not differ significantly between studies enrolling only patients with documented myocardial ischaemia and those studies enrolling patients regardless of presence of ischaemia. However, ischaemia documented by non-invasive imaging techniques was associated with a higher incidence of events (P = 0.02). Overall, these patients, however, suffered from a high incidence of recurrent hospitalization. Conclusion: Angina without obstructive CAD has a heterogeneous prognosis. A main determinant of major adverse events is the presence of 'some' coronary atherosclerosis, with unequivocal myocardial ischaemia being associated with worse clinical outcomes. Patients' quality of life is also worsened by the high incidence of hospitalization, angina recurrence, and repeated coronary angiography.

Impaired coronary metabolic dilation in the metabolic syndrome is linked to mitochondrial dysfunction and mitochondrial DNA damage.

Mitochondrial dysfunction in obesity and diabetes can be caused by excessive production of free radicals, which can damage mitochondrial DNA. Because mitochondrial DNA plays a key role in the production of ATP necessary for cardiac work, we hypothesized that mitochondrial dysfunction, induced by mitochondrial DNA damage, uncouples coronary blood flow from cardiac work. Myocardial blood flow (contrast echocardiography) was measured in Zucker lean (ZLN) and obese fatty (ZOF) rats during increased cardiac metabolism (product of heart rate and arterial pressure, i.v. norepinephrine). In ZLN increased metabolism augmented coronary blood flow, but in ZOF metabolic hyperemia was attenuated. Mitochondrial respiration was impaired and ROS production was greater in ZOF than ZLN. These were associated with mitochondrial DNA (mtDNA) damage in ZOF. To determine if coronary metabolic dilation, the hyperemic response induced by heightened cardiac metabolism, is linked to mitochondrial function we introduced recombinant proteins (intravenously or intraperitoneally) in ZLN and ZOF to fragment or repair mtDNA, respectively. Repair of mtDNA damage restored mitochondrial function and metabolic dilation, and reduced ROS production in ZOF; whereas induction of mtDNA damage in ZLN reduced mitochondrial function, increased ROS production, and attenuated metabolic dilation. Adequate metabolic dilation was also associated with the extracellular release of ADP, ATP, and H2O2 by cardiac myocytes; whereas myocytes from rats with impaired dilation released only H2O2. In conclusion, our results suggest that mitochondrial function plays a seminal role in connecting myocardial blood flow to metabolism, and integrity of mtDNA is central to this process.

Pharmacological Agents Targeting Myocardial Metabolism for the Management of Chronic Stable Angina : an Update.

Despite continuous advances in myocardial revascularization procedures and intracoronary devices, patients with ischemic heart disease (IHD) still experience worse prognosis and poor quality of life (QoL). Indeed, chronic stable angina (CSA) is a common disease with a large burden on healthcare costs. Traditionally, CSA is interpreted as episodes of reversible myocardial ischemia related to the presence of stable coronary artery plaque causing myocardial demand/supply mismatch when myocardial oxygen consumption increases. Accordingly, revascularization procedures are performed with the aim to remove the flow limiting stenosis, whereas traditional medical therapy (hemodynamic agents) aims at reducing myocardial oxygen demands. However, although effective, none of these treatment strategies or their combination is either able to confer symptomatic relief in all patients, nor to reduce mortality. Failure to significantly improve QoL and prognosis may be attributed at least in part to this "restrictive" understanding of IHD. Despite for many years myocardial metabolic derangement has been overlooked, recently it has gained increased attention with the development of new pharmacological agents (metabolic modulators) able to influence myocardial substrate selection and utilization thus improving cardiac efficiency. Shifting cardiac metabolism from free fatty acids (FA) towards glucose is a promising approach for the treatment of patients with stable angina, independently of the underling disease (macrovascular and/or microvascular disease). In this sense cardiac metabolic modulators open the way to a "revolutionary" understanding of ischemic heart disease and its common clinical manifestations, where myocardial ischemia is no longer considered as the mere oxygen and metabolites demand/supply unbalance, but as an energetic disorder. Keeping in mind such an alternative approach to the disease, development of new pharmacological agents directed toward multiple metabolic targets is mandatory.

The potential value of integrated natriuretic peptide and echo-guided heart failure management.

There is increasing interest in guiding Heart Failure (HF) therapy with Brain Natriuretic Peptide (BNP) or N-terminal prohormone of Brain Natriuretic Peptide (NT-proBNP), with the goal of lowering concentrations of these markers (and maintaining their suppression) as part of the therapeutic approach in HF. However, recent European Society of Cardiology (ESC) and American Heart Association/ American College of Cardiology (AHA/ACC) guidelines did not recommend biomarker-guided therapy in the management of HF patients. This has likely to do with the conceptual, methodological, and practical limitations of the Natriuretic Peptides (NP)-based approach, including biological variability, slow time-course, poor specificity, cost and venipuncture, as well as to the lack of conclusive scientific evidence after 15 years of intensive scientific work and industry investment in the field. An increase in NP can be associated with accumulation of extra-vascular lung water, which is a sign of impending acute heart failure. If this is the case, an higher dose of loop diuretics will improve symptoms. However, if no lung congestion is present, diuretics will show no benefit and even harm. It is only a combined clinical, bio-humoral (for instance with evaluation of renal function) and echocardiographic assessment which may unmask the pathophysiological (and possibly therapeutic) heterogeneity underlying the same clinical and NP picture. Increase in B-lines will trigger increase of loop diuretics (or dialysis); the marked increase in mitral insufficiency (at baseline or during exercise) will lead to increase in vasodilators and to consider mitral valve repair; the presence of substantial inotropic reserve during stress will give a substantially higher chance of benefit to beta-blocker or Cardiac Resynchronization Therapy (CRT). To each patient its own therapy, not with a "blind date" with symptoms and NP and carpet bombing with drugs, but with an open-eye targeted approach on the mechanism predominant in that individual patient. A monocular, specialistic, unidimensional approach to HF can miss its pathogenetic and clinical complexity, which only can be overcome with an integrated, versatile and tailored approach.

Myocardial energy balance and metabolism as causes of myocardial ischemia.

The current approach to myocardial ischemia has been influenced by the misconception of a close link between ischemia and coronary atherosclerotic obstructions. Recent guidelines have, however, acknowledged the multifactorial nature of this condition, with an identifiable cause present in less than half of angina patients, and a large fraction with angina of unknown origin. Because of this background, focusing on cardiac energy metabolim offers new opportunities to manage myocardial ischemia even when its cause is unknown.

Hydrogen peroxide mediates endothelium-dependent dilation of coronary arterioles in obese rats on a low-carbohydrate diet.

OBJECTIVE: Endothelium-dependent vasodilation of coronary arterioles is impaired in obese rats and may be improved by a LCD. The aim of this study is to elucidate the mechanism by which this improvement occurs. METHODS: We used four groups of male Zucker rats: lean and obese on either SD or LCD. Coronary arterioles were cannulated and pressurized for diameter measurements during administration of acetylcholine or sodium nitroprusside or during flow. Real-time PCR was performed to quantify mRNA expression of CuZnSOD and catalase. RESULTS: The LCD significantly increased endothelium-dependent dilation in the obese rats. l-NAME and indomethacin reduced responses to flow and acetylcholine in the lean rats without any effect on the obese on either diet. In contrast, TEA and catalase blocked flow-dependent and acetylcholine-induced dilation in the obese on either diet, while no effect was observed on the lean. The LCD in the obese significantly up-regulated catalase mRNA expression and slightly increased CuZnSOD mRNA levels. CONCLUSIONS: A LCD improves endothelium-dependent vasodilation of coronary arterioles in obese rats through the production of H2 O2 which acts as a hyperpolarizing factor, independent of nitric oxide and PGI2 .

A multiparametric clinical and echocardiographic score to risk stratify patients with chronic systolic heart failure: derivation and testing.

Although echo Doppler and biomarkers are the most common examinations performed worldwide in heart failure (HF), they are rarely considered in risk scores. In outpatients with chronic HF and left ventricular ejection fraction (LVEF) ≤45%, data on clinical status, echo Doppler variables, aminoterminal pro-type B natriuretic peptide (NT-proBNP), estimated glomerular filtration rate (eGFR), and drug therapies were combined to build up a multiparametric score. We randomly selected 250 patients to produce a derivation cohort and 388 patients were used as a testing cohort. Follow-up lasted 29 ± 23 months. The univariable predictors that entered into the multivariable Cox model were as follows: furosemide daily dose >25 mg, inability to tolerate angiotensin converting enzyme (ACE) inhibitors, inability to tolerate ß-blockers, age >75 years, New York Heart Association (NYHA) >2, eGFR<60 mL/min, NT-proBNP plasma levels above the median, tricuspid plane systolic excursion (TAPSE) ≤14 mm, LV end-diastolic volume index (LVEDVi) >96 mL/m(2) , moderate-to-severe mitral regurgitation (MR) and LVEF <30%. The scores of prognostic factors were obtained with the respective odds ratio divided by the lower odd ratio: 4 points for furosemide dose, 3 points for age, NT-proBNP, LVEDVi, TAPSE, 2 points for inability to tolerate ß-blockers, inability to tolerate ACE inhibitors, NYHA, eGFR<60 mL/min, moderate-to-severe MR, 1 point for LVEF. The multiparametric score predicted all-cause mortality either in the derivation cohort (68.4% sensitivity, 79.5% specificity, area under the curve [AUC] 78.7%) or in the testing cohort (73.7% sensitivity, 71.3% specificity, AUC 77.2%). All-cause mortality significantly increased with increasing score both in the derivation and in the testing cohort (P < 0.0001). In conclusion, this multiparametric score is able to predict mortality in chronic systolic HF.

Advantages of real time three-dimensional echocardiography in the assessment of right ventricular volumes and function in patients with pulmonary hypertension compared with conventional two-dimensional echocardiography.

BACKGROUND: In recent years, right ventricular (RV) function has acquired greater relevance as a clinical and prognostic marker in many physiopathological conditions. The study aims to point out the value of real time three-dimensional echocardiography (RT3DE) and tissue Doppler imaging (TDI) in the evaluation of patients affected by pulmonary hypertension (PH), compared with conventional two-dimensional (2D) echocardiography. METHODS: We enrolled 44 subjects affected by PH who underwent 2D and Doppler echocardiography, RT 3D Echocardiography and TDI evaluation of the RV, and a healthy control group. PH itself can induce severe functional and structural abnormalities of the RV, such as RV hypertrophy, RV dilation, and RV systolic and diastolic dysfunction. RESULTS: In this study, RV FAC, and TAPSE showed marked alterations in patients with PH compared to the control group (C): (RVFAC: [PH] 0.29 ± 0.07 vs. [C] 0.49 ± 0.05%, P < 0.0001; TAPSE: [PH] 15.3 ± 3.2 vs. [C] 21.1 ± 2.6 mm, P > 0.0001). The 3D RV end-diastolic volume was significantly higher in PH than in C (PH) (138.7 ± 25.3 vs. [C] 82.8 ± 12.5 mL, P < 0.0001] as well as 3D RV end-systolic volume (PH) (97.6 ± 21.5 vs. [C] 39.3 ± 9.5 mL, P < 0.0001). The 3D RV ejection fraction (EF) was significantly lower in the pulmonary hypertension group than in healthy subjects (31.8 ± 6.8 vs. [C] 52.5 ± 4.7%, P < 0.0001). CONCLUSIONS: In patients with PH, evaluation of the RV diastolic and systolic volume and EF by RT3DE has shown a higher discriminating power in comparison, respectively, with 2DRV diastolic area and the relative fractional area changes.

Ischemia with no obstructive coronary artery disease (INOCA): A patient self-report quality of life survey from INOCA international.

BACKGROUND: There is limited information available regarding evidence of ischemia with no obstructive coronary arteries (INOCA) and quality of life. PURPOSE: To determine associations between INOCA and self-reported physical, social, and mental health. METHODS: We conducted a survey of all members (n = 1579) of the INOCA International patient support group. Current self-reported diagnosis and health measures were collected. Functional capacity was retrospectively estimated using the Duke Activity Status Index (DASI), assessing levels of activities performed prior and after symptom onset. RESULTS: A total of 297 (20.8% response rate, 91% women) reported symptoms of chest pain, pressure, or discomfort in 92.9%. Overall, 34.4% were living with symptoms for ≥3 years before an INOCA diagnosis, and 77.8% were told their symptoms were not cardiac. Estimated functional capacity was higher prior to compared to after symptom onset (8.6 ± 1.8 METs vs 5.6 ± 1.8 METs; P < 0.0001). Most respondents reported an adverse impact of symptoms on their home life (80.5%), social life (80.1%), mental health (70.4%), outlook on life (69.7%), sex life (55.9%), and their partner/spouse relationship (53.9%), while approximately three-quarters reduced their work hours or stopped work completely, 47.5% retired early, and 38.4% applied for disability. CONCLUSIONS: INOCA symptoms are associated with adverse physical, mental and social health quality of life. Increased patient awareness, physician recognition and diagnosis, and clinical trials are needed to develop evidence-based guidelines for this increasingly recognized cardiovascular disorder.

Sex Differences in Quality of Life in Patients with Ischemia with No Obstructive Coronary Artery Disease (INOCA): A Patient Self-Report Retrospective Survey from INOCA International.

Women with obstructive coronary artery disease (CAD) have a relatively lower quality of life (QoL) compared to men, but our understanding of sex differences in QoL in ischemia with no obstructive coronary artery disease (INOCA) is limited. We conducted a survey of patient members of INOCA International with an assessment of self-reported health measures. Functional capacity was retrospectively estimated using the Duke Activity Status Index (DASI), assessing levels of activities performed before and after INOCA symptom onset. Of the 1579 patient members, the overall survey completion rate was 21%. Women represented 91% of the respondents. Estimated functional capacity, expressed as metabolic equivalents (METs), was higher before compared to after INOCA diagnosis comparably for both women and men. For every one MET decline in functional capacity, there was a significantly greater decline in QoL for men compared with women in physical health (4.0 ± 1.1 vs. 2.9 ± 0.3 days/month, p < 0.001), mental health (2.4 ± 1.2 vs. 1.8 ± 0.3 days/month, p = 0.001), and social health/recreational activities (4.1 ± 1.0 vs. 2.9 ± 0.3 days/month, p = 0.0001), respectively. In an international survey of patients living with INOCA, despite similar diagnoses, clinical comorbidities, and symptoms, INOCA-related functional capacity declines are associated with a greater adverse impact on QoL in men compared to women.