Coronary Microvascular Vasodilatory Function: Related Clinical Features and Differences According to the Different Coronary Arteries and Types of Coronary Spasm

Background: In the clinical setting; the microvascular vasodilatory function test (MVFT) with a pressure wire has been used in ischaemia patients with non-obstructive coronary arteries (INOCA), including vasospastic angina (VSA) and microvascular angina (MVA). The exact factors that affect the microvascular vasodilatory function (MVF) in such patients are still unknown. We aimed to identify the factors, including clinical parameters and lesion characteristics, affecting the MVF in such patients. Methods: A total of 53 patients who underwent coronary angiography, spasm provocation tests (SPTs) and MVFTs were enrolled. In the MVFT, the coronary flow reserve (CFR) and index of microcirculatory resistance (IMR) were measured. Of the 53 patients, MVFT data in the left anterior descending coronary artery (LAD) were obtained from 49 patients, and the clinical parameters were checked in all of them. Based on the results of the SPT, coronary spasms were divided into focal spasm, diffuse spasm, and microvascular spasm (MVS). To assess the lesion characteristics influencing MVF, MVFT data were compared according to the types of coronary spasm and coronary vessels in 73 vessels of the 53 patients. Results: In 49 patients who underwent the MVFT in the LAD, the IMR was higher in active smokers (n = 7) than in former smokers (n = 15) and never smokers (n = 27, p < 0.01). In the 73 coronary arteries in this study, the type of coronary spasm did not correlate with the CFR or IMR, whereas a higher IMR were more frequently observed in cases of focal spasm than in cases of diffuse spasm (p = 0.03). In addition, the IMR was higher in the right coronary artery (RCA) than in the LAD (p = 0.02). Conclusion: These results indicate that the smoking status affected the MVF in patients with INOCA, suggesting the possibility of improvement in the MVF by smoking cessation in such patients. In addition, in the assessment of MVF, it may be important to take into account which coronary artery or types of coronary spasm are being evaluated.

Myocardial infarction with non obstructive coronary arteries (MINOCA) according to definitions of 2020 ESC Guidelines: clinical profile and prognosis

Background MINOCA's physiopathology, treatment and prognosis are yet to be completely understood. The aim of this study is to compare baseline characteristics and prognosis of MINOCA patients and those of patients with myocardial infarction (MI) and obstructive coronary arteries. Methods We analysed all consecutive patients with MI who underwent coronary angiography admitted in a University Hospital covering a population of 220.000 people during a period of 60 months. The database and the all the patient's angiographies were revised by a group of experts in order to adequate MINOCA to 2020 ESC Guidelines definition and the American Heart Association position paper. Results 680 patients, 68 of whom were MINOCA (10%) with a median of follow up of 31±16 months were analysed (see table 1). We found no differences in both groups' age. Female gender was more prevalent among MINOCA patients. The underlying mechanism in MINOCA was coronary spasm (17.6%), plaque rupture (13.2%), coronary embolism (7.4%), coronary dissection (2.9%), type II infarction (19.1%) or unknown (39.7%). Coronary arteries in MINOCA patients had no obstructions at all in 57.4%, and 30–50% obstruction in 42.6% of the cases. MINOCA patients didn't have higher prevalence of cancer, autoimmune or psychiatric diseases, dyslipidaemia, hypertension or inflammatory analytical parameters. However, we found significant differences in atrial fibrillation, migraine, connective tissue diseases, tobacco use and diabetes. We found no effect of stress in the development of MINOCA (measured with validated STAI and DS-14 scales). Symptoms at admission didn't differ between the two groups, but those with MINOCA had normal ECG more frequently. Prognosis showed relevant differences, as MINOCA patients had less major cardiovascular complications, such as inotropic requirements (0% Vs 4.8%, p=0.04), shock (0% vs 6.6%, p=0.013) and left ventricular dysfunction (11.8 vs 30.2, p=0.015). Furthermore, myocardial injury biomarkers' levels were, significantly lower in MINOCA patients. Death rates tend to be lower both in hospital (0% vs 3.1%, p=0.131) and during follow up (9.1% vs 11.5%, p=0.369). Conclusion Analysing MINOCA patients' clinical profile might help us understanding the underlying physiopathology, prognosis and treatment targets. In these patients, classic cardiovascular risk factors don't appear to be as important as in obstructive patients. At admission, we found no clinical differences that could help making an early diagnosis, even if those with normal ECG and lower levels of myocardial injury biomarkers are more likely to have non-obstructive coronary arteries. These patients seem to have better prognosis and lower myocardial injury than those with obstructive coronary arteries. Further research is needed to provide more evidence on the accurate treatment of these patients. FUNDunding Acknowledgement Type of funding sources: None.

Healed plaque erosion as a cause of recurrent vasospastic angina: a case report

Background Recurrent vasospastic angina sometimes occurs. Fresh thrombi have been known to arise without plaque rupture at coronary spasm sites due to blood flow stagnation and intimal erosion caused by vasospasms. The relationship between recurrence of vasospastic angina and thrombus formation remains unclear. Case summary A 67-year-old man presented with sudden chest pain at rest. Electrocardiography and coronary angiography indicated vasospastic angina. His chest pain persisted despite the administration of benidipine, isosorbide mononitrate, nicorandil, and nifedipine. Coronary angiography performed one month after initial presentation showed stenosis refractory to isosorbide administration. Optical coherence tomography revealed a healed plaque, and a stent was deployed. The patient remained symptom-free at 1-year follow-up. Discussion Prolonged coronary vasospasm with limited coronary blood flow could induce total occlusion of the coronary artery, and acute thrombus formation, which resulted in healed plaque erosion. When vasospastic angina cannot be controlled, rapidly progressive stenosis caused by healed plaque erosion could be its underlying cause and mechanism. This report indicates that antiplatelet therapy may be a preventive option for future recurrent vasospastic angina, especially in those caused by healed plaques.

Pathophysiology and Diagnosis of Coronary Functional Abnormalities

Approximately one-half of patients undergoing diagnostic coronary angiography for angina have no significant coronary atherosclerotic stenosis. This clinical condition has recently been described as ischaemia with non-obstructive coronary arteries (INOCA). Coronary functional abnormalities are central to the pathogenesis of INOCA, including epicardial coronary spasm and coronary microvascular dysfunction composed of a variable combination of increased vasoconstrictive reactivity and/or reduced vasodilator function. During the last decade – in INOCA patients in particular – evidence for the prognostic impact of coronary functional abnormalities has accumulated and various non-invasive and invasive diagnostic techniques have enabled the evaluation of coronary vasomotor function in a comprehensive manner. In this review, the authors briefly summarise the recent advances in the understanding of pathophysiology and diagnosis of epicardial coronary artery spasm and coronary microvascular dysfunction.

Mimic high lateral myocardial infarction in chest tetany with mirror electrocardiographic change, Movable phenomenon (Yasser’s phenomenon), and coronary spasm; dramatic Oxygen reversal

Rationale: Tetany is a common, serious, well-established endocrinal and metabolic hypocalcemic disorder. Chest tetany is a novel metabolic term in hypocalcemia characterized by acute severe twisting chest pain. Movable phenomenon (Yasser’s phenomenon) is a new phenomenon that is usually associated with hypocalcemia. oxygenation may have a role in the management of coronary artery spasm. Patient concerns: A middle-aged farmer smoker male patient presented to physician outpatient clinic with tetany, mimic high lateral myocardial infarction, mirror electrocardiographic change, Movable phenomenon (Yasser’s phenomenon), and coronary artery spasm. Diagnosis: Mimic high lateral myocardial infarction in chest tetany with mirror electrocardiographic change, Movable phenomenon (Yasser’s phenomenon), and coronary artery spasm. Interventions: Electrocardiography, oxygenation, IV calcium injection, and echocardiography. Outcomes: Acute dramatic clinical and electrocardiographic improvement had happened. Lessons: The reversal of mirror electrocardiographic change, reversal of ST-segment depression coronary artery spasm, and normalization of Movable phenomenon (Yasser’s phenomenon) after oxygenation. It signifies the role of oxygen in both coronary artery spasm and tetany. Mirror local electrocardiographic change is a novel described expression that may reflect the myocardial polarity in this chest tetany.

A Case Report of Non-Atherosclerotic Driven Myocardial Infarction in a Patient Presenting with Coronary Artery Spasm

Background: Non-atherosclerotic processes are regarded as equally important contributors to a substantial number of coronary problems mainly myocardial infarction. This includes coronary spasm which has been considered as one of the coronary syndromes leading to myocardial infarction. These non-atherosclerotic events ensuing in major averse cardiac events (MACE) not only require various diagnostic and therapeutic strategies but also there is a need to delineate the underlying etiology for their effective treatment and management. Case Summary: We report a case of anterior wall myocardial infarction (AWMI) driven by a non-atherosclerotic event i.e. coronary spasm. Concomitant marked ST-segment elevation recorded on ECG revealed a diffuse mid distal disease in our patient. We report here the initial presentation, coronary care & intervention and throughout the clinical course of our patient. Conclusion: Myocardial infarctionsinvolving non-atherosclerotic causes in young individuals as in our study should be reported by medical practitioners and given equal importance as they might indicate the underlying root cause of such events. Effective treatment of such future cases can be done by taking management strategies, diagnostic findings and prognostic data into consideration.