Invasive Coronary Assessment in Myocardial Ischemia with No Obstructive Coronary Arteries.

PURPOSE OF REVIEW: The purpose of this review is threefold: (i) to give an overview of well-established invasive methods for assessing patients with ischemia with no obstructive coronary arteries (INOCA) in the cardiac catheterization laboratory; (ii) to describe the prognostic and treatment implications based on these findings, and (iii) to discuss current knowledge gaps and future perspectives. RECENT FINDINGS: Recent studies have demonstrated that invasive coronary function testing not only allows for risk stratification of patients with INOCA but also guides medical therapy with improvement in symptoms and quality of life. Based on these findings, invasive coronary function assessment is now a class 2a recommendation in the 2021 ACC/AHA chest pain guideline to improve the diagnosis of coronary microvascular dysfunction and to enhance risk stratification. Invasive functional testing for patients with INOCA is well established and easily performed in the catheterization laboratory. Comprehensive invasive assessment is a key to differentiating INOCA endotypes and optimizing both medical therapy and preventive strategies including lifestyle modification.

Comprehensive Management of ANOCA, Part 1-Definition, Patient Population, and Diagnosis: JACC State-of-the-Art Review.

Angina with nonobstructive coronary arteries (ANOCA) is increasingly recognized and may affect nearly one-half of patients undergoing invasive coronary angiography for suspected ischemic heart disease. This working diagnosis encompasses coronary microvascular dysfunction, microvascular and epicardial spasm, myocardial bridging, and other occult coronary abnormalities. Patients with ANOCA often face a high burden of symptoms and may experience repeated presentations to multiple medical providers before receiving a diagnosis. Given the challenges of establishing a diagnosis, patients with ANOCA frequently experience invalidation and recidivism, possibly leading to anxiety and depression. Advances in scientific knowledge and diagnostic testing now allow for routine evaluation of ANOCA noninvasively and in the cardiac catheterization laboratory with coronary function testing (CFT). CFT includes diagnostic coronary angiography, assessment of coronary flow reserve and microcirculatory resistance, provocative testing for endothelial dysfunction and coronary vasospasm, and intravascular imaging for identification of myocardial bridging, with hemodynamic assessment as needed.

Comprehensive Management of ANOCA, Part 2-Program Development, Treatment, and Research Initiatives: JACC State-of-the-Art Review.

Centers specializing in coronary function testing are critical to ensure a systematic approach to the diagnosis and treatment of angina with nonobstructive coronary arteries (ANOCA). Management leveraging lifestyle, pharmacology, and device-based therapeutic options for ANOCA can improve angina burden and quality of life in affected patients. Multidisciplinary care teams that can tailor and titrate therapies based on individual patient needs are critical to the success of comprehensive programs. As coronary function testing for ANOCA is more widely adopted, collaborative research initiatives will be fundamental to improve ANOCA care. These efforts will require standardized symptom assessments and data collection, which will propel future large-scale clinical trials.

Safety of Provocative Testing With Intracoronary Acetylcholine and Implications for Standard Protocols.

BACKGROUND: Heterogeneity in diagnostic criteria and provocation protocols has posed challenges in understanding the safety of coronary provocation testing with intracoronary acetylcholine (ACh) for the contemporary diagnosis of epicardial and microvascular spasm. OBJECTIVES: We examined the safety of testing and subgroup differences in procedural risks based on ethnicity, diagnostic criteria, and provocation protocols. METHODS: PubMed and Embase were searched in November 2021 to identify original articles reporting procedural complications associated with intracoronary ACh administration. The primary outcome was the pooled estimate of the incidence of major complications including death, myocardial infarction, ventricular tachycardia/fibrillation, and shock. RESULTS: A total of 16 studies with 12,585 patients were included in the meta-analysis. The overall pooled estimate of the incidence of major complications was 0.5% (95% CI: 0.0%-1.3%) without any reports of death. Exploratory subgroup analyses revealed that the pooled incidence of major complications was significantly higher in the studies that followed the contemporary diagnosis criteria for epicardial spasm defined as ≥90% diameter reduction (1.0%; 95% CI: 0.3%-2.0%) but significantly lower in Western populations (0.0%; 95% CI: 0.0%-0.45%). The rate of positive epicardial spasm and the incidence of major complications were similar between provocation protocols using the maximum ACh doses of 100 µg and 200 µg. CONCLUSIONS: Intracoronary ACh administration for the contemporary diagnosis of epicardial and microvascular spasm is a safe procedure. Moreover, excellent safety records are observed in Western populations primarily presenting with myocardial ischemia and/or infarction with nonobstructive coronary arteries. This study will help standardize ACh testing to improve clinical diagnosis and ensure procedural safety.

Role of Stress Cardiac Magnetic Resonance Imaging in Women with Suspected Ischemia but No Obstructive Coronary Artery Disease.

OBJECTIVE: Signs and symptoms of ischemia but no obstructive coronary artery disease (CAD) is often a diagnostic dilemma in women. The use of stress cardiac magnetic resonance imaging (CMRI) for advanced diagnostic assessment in these patients is a non-ionizing radiation option, but the diagnostic utility in this population is unknown. We examined the diagnostic role of stress CMRI in our patient population of these women. METHODS: We analyzed 113 consecutive female patients from 2/2006-11/2007 who had prior cardiac evaluations for signs and symptoms of ischemia but no obstructive CAD who underwent stress CMRI, which included anatomic, functional, adenosine stress perfusion and delayed enhancement imaging. RESULTS: The population demographics of 113 women included a mean age of 55±12.2 years with an average body mass index (BMI) of 25 ± 4.5. Overall, 43% had hypertension, 4% had diabetes and 3% were smokers. Overall, 80/113 (70%) demonstrated abnormal stress CMRI results. The majority of patients demonstrated findings consistent with subendocardial perfusion abnormalities suggestive of coronary microvascular dysfunction (CMD). Of note, 3 patients (4%) were diagnosed with congenital coronary anomalies or cardiomyopathy not detected in prior cardiac evaluations. CONCLUSION: Among women with signs and symptoms of ischemia but no obstructive CAD, stress CMRI is frequently abnormal and is valuable in diagnosis of CMD. Stress CMRI appears useful for advanced diagnostic assessment in these diagnostically challenged patients.