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Background: The coronary slow flow phenomenon (CSFP) is an angiographic finding characterised by the delayed passage of contrast through the coronary arteries, despite the absence of obstructive coronary artery disease (defined as less than 50% narrowing of the vessel lumen). Patients with the CSFP experience recurrent angina, for which there are limited evidence-based therapies. Ticagrelor may serve as an effective anti-anginal therapy for these patients by increasing adenosine levels, which could alleviate coronary microvascular dysfunction and its associated angina due to its vasodilatory properties. This study aimed to determine the anti-anginal efficacy of ticagrelor 90 mg taken twice daily on spontaneous angina episodes in patients with refractory angina (i.e., episodes ≥3/week despite two anti-anginals) and documented CSFP. Methods: In a randomised, double-blind, placebo-controlled, cross-over trial, the anti-anginal efficacy of a 4-week ticagrelor therapy regimen was evaluated in 20 patients with refractory angina (mean age 61.5 ± 10.5 years; 40% women) who had documented slow coronary flow. The primary endpoint was the frequency of angina episodes, recorded using an angina diary. Secondary endpoints included the duration and severity of angina episodes, consumption of short-acting nitrates, and health status evaluations using the Seattle Angina Questionnaire (SAQ) and the Short Form-36 (SF-36) indices. Results: During the four weeks of therapy, ticagrelor did not significantly improve angina symptoms compared to the placebo (placebo 25.7 (16.7)) vs. ticagrelor 19.8 (18.1), p > 0.05). Furthermore, it did not impact other patient-related outcome measures, including angina severity, duration, frequency of prolonged angina episodes, nitrate consumption, or the SAQ/SF-36 health outcome indices. No serious adverse events related to the study drug were observed. Conclusions: In patients with documented CSFP who were unresponsive to standard anti-anginal therapy, ticagrelor did not reduce the frequency of spontaneous angina episodes or the consumption of nitrates. Further confirmation of the potential benefits of this therapy may be obtained through a larger clinical trial. [ABSTRACT FROM AUTHOR]

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The universal definition of acute myocardial infarction (MI) requires both evidence of myocardial injury and myocardial ischaemia. In MINOCA (MI with non-obstructive coronary arteries), patients must fulfil this MI criteria, but is their chest pain similar to those who have MI with obstructive CAD (MICAD)? This study compares prospectively collected chest pain features between patients with MINOCA and MICAD. Utilising the Coronary Angiogram Database of South Australia (CADOSA), consecutive MI patients were categorized as MINOCA or MICAD based on angiographic findings. Chest pain data were collected via direct patient interviews by trained staff members. Of 6811 consecutive patients fulfilling a clinical MI diagnosis, 411 (6.0%) were MINOCA, and 5948 MICAD. The MINOCA patients were younger, more often female and had less cardiovascular risk factors than those with MICAD. There were no significant differences in chest pain characteristics between the MINOCA and MICAD cohorts in relation to pain location, quality, associated symptoms, or duration. In conclusion, MINOCA patients have chest pain characteristics that are indistinguishable from MICAD patients, suggesting that their pain is ischaemic in nature. Thus, in the presence of positive myocardial injury markers, ischaemic chest pain fulfils the universal criteria for MI, despite the absence of obstructive coronary artery disease. [ABSTRACT FROM AUTHOR]

Introduction: Patients with Troponin positive Non-Obstructive Coronary Arteries (TpNOCA) warrant further investigation to elucidate the ischemic or non-ischemic cause of the suspected acute myocardial infarct (AMI) presentation. Patients clinically diagnosed with an underlying ischemic cause are subsequently referred to as MI with Non-Obstructive Coronary Arteries (MINOCA). This study evaluates the 2-year major adverse cardiac events (MACE) of MINOCA and secondly compares the outcomes of MINOCA patients with smooth coronaries and minor CAD. Methods: Consecutive patients undergoing angiography for AMI were captured in the Coronary Angiogram Database of South Australia (CADOSA) registry. Patients were categorised as TpNOCA based on the universal criteria for MI and absence of obstructive stenosis (<50%). TpNOCA patients diagnosed with a non-ischemic pathology (e.g. myocarditis) were excluded and the remaining MINOCA patients were categorised as minor CAD (stenosis <50%) or smooth coronaries (0% stenosis). The 2-year MACE (all-cause mortality and readmission for MI, angina, heart failure or stroke) was extracted from administrative data sets. Results: Between 2012-15, 6,811 angiographic procedures were undertaken for AMI, and 13% (882) were classified as TpNOCA, of which, 37% (322) were identified as MINOCA. MINOCA patients were: aged 60±16 yrs, 60% females, 57% hypertensive, 52% with hyperlipidaemia, 30% smokers and 20% with diabetes. Minor CAD was evident in 49% (157). Compared to MINOCA with minor CAD, those with smooth coronaries were younger (58±16 vs. 62±15 yrs p<0.05) and less likely to be females (52% vs 68%, p<0.05). Overall MACE at 2 years was 27% comprising of 3.7% mortality and 26% readmissions. The MACE was similar for MINOCA patients with smooth coronaries and minor CAD (24% vs 31%, OR 0.73, 95%CI 0.45-1.2, p>0.05, age adjusted) although a trend towards lower readmissions in the smooth coronaries group was observed (21% vs 30%, OR 0.64, 95%CI 0.4-1.1, p=0.09, age adjusted). Conclusions: Clinical outcomes in MINOCA warrant further scrutiny with 1 in 4 patients experiencing MACE within 2 years. Larger studies are needed to identify patients at high risk for adverse outcomes so secondary prevention strategies can be optimised. [ABSTRACT FROM AUTHOR]

MI with non-obstructive coronary arteries (MINOCA) is an enigma that is being increasingly recognised with the frequent use of angiography following acute MI. To diagnose this condition, it is important to determine the multiple potential underlying mechanisms that may be responsible, many of which require different treatments. This review evaluates the contemporary diagnosis and management of MINOCA., Competing Interests: Disclosure: The authors have no conflicts of interest to disclose.