Hyperventilation testing in the diagnosis of vasospastic angina: A clinical review and meta-analysis.

BACKGROUND: Given the limited access to invasive vasospastic reactivity testing in Western Countries, there is a need to further develop alternative non-invasive diagnostic methods for vasospastic angina (VSA). Hyperventilation testing (HVT) is defined as a class IIa recommendation to diagnose VSA by the Japanese Society of Cardiology. METHODS: In this systematic review and meta-analysis reported according to the PRISMA statement, we review the mechanisms, methods, modalities and diagnostic accuracy of non-invasive HVT for the diagnostic of VSA. RESULTS: A total of 106 articles published between 1980 and 2022 about VSA and HVT were included in the systematic review, among which 16 were included in the meta-analysis for diagnostic accuracy. Twelve electrocardiogram-HVT studies including 804 patients showed a pooled sensitivity of 54% (95% confidence intervals [CI]; 30%-76%) and a pooled specificity of 99% (95% CI; 88%-100%). Four transthoracic echocardiography-HVT studies including 197 patients revealed a pooled sensitivity of 90% (95% CI; 82%-94%) and a pooled specificity of 98% (95% CI; 86%-100%). Six myocardial perfusion imaging-HVT studies including 112 patients yielded a pooled sensitivity of 95% (95% CI; 63%-100%) and a pooled specificity of 78% (95% CI; 19%-98%). Non-invasive HVT resulted in a low rate of adverse events, ventricular arrhythmias being the most frequently reported, and were resolved with the administration of nitroglycerin. CONCLUSIONS: Non-invasive HVT offers a safe alternative with high diagnostic accuracy to diagnose VSA in patients with otherwise undiagnosed causes of chest pain.

Long-term prognostic factors for cardiovascular events in patients with chest pain without diabetes mellitus nor significant coronary stenosis.

Chest pain is the most common symptom of coronary artery disease (CAD) and diabetes mellitus (DM) is a well-known single strongest risk factor for cardiovascular diseases. Thus, the impact of CAD nor DM on long-term clinical effects is reported widely, but the prognostic factors of non-DM patients presenting with chest pain without significant CAD are limited. A total of 1,046 patients with chest pain without DM and significant CAD who underwent coronary angiography (CAG) and acetylcholine (ACH) provocation tests were finally enrolled. Propensity score matching and multivariate Cox-proportional hazard ratio analysis were performed to adjust for baseline potential confounders. Major adverse cardiac and cerebrovascular events (MACCE) were defined as the composite of total death, myocardial infarction (MI), revascularization, stroke, and recurrent angina. This study aimed to evaluate the long-term prognostic factors for MACCE in patients with chest pain without DM and CAD up to 5 years. Coronary artery spasm (CAS) was the most common cause of chest pain. However, long-term MACCE of CAS was not worse than those of patients with chest pain without CAS when patients with CAS had subsequent optimal antianginal medication therapy. However, a recurrent chest pain remains a problem even with continuous antianginal medication therapy. Up to 5 years, the incidence of MACCE was in 7.3%, including recurrent angina 6.9%. Dyslipidemia (HR: 2.010, 95% CI 1.166-3.466, P = 0.012), mild-moderate (30-70%) coronary stenosis (HR: 2.369, 95% CI 1.118-5.018, P = 0.024), the use of aspirin (HR: 2.885, 95% CI 1.588-5.238, P < 0.001), and the use of nitrates (HR: 1.938, 95% CI 1.094-3.433, P = 0.023) were independent risk factors for MACCE. Among the patients with chest pain without DM and significant CAD, the incidence of MACE were rare, but recurrent angina was still a challenging problem who had treated with antianginal medications.

Phosphorylated CPI-17 and MLC2 as Biomarkers of Coronary Artery Spasm-Induced Sudden Cardiac Death.

Coronary artery spasm (CAS) plays an important role in the pathogeneses of various ischemic heart diseases and has gradually become a common cause of life-threatening arrhythmia. The specific molecular mechanism of CAS has not been fully elucidated, nor are there any specific diagnostic markers for the condition. Therefore, this study aimed to examine the specific molecular mechanism underlying CAS, and screen for potential diagnostic markers. To this end, we successfully constructed a rat CAS model and achieved in vitro culture of a human coronary-artery smooth-muscle cell (hCASMC) contraction model. Possible molecular mechanisms by which protein kinase C (PKC) regulated CAS through the C kinase-potentiated protein phosphatase 1 inhibitor of 17 kDa (CPI-17)/myosin II regulatory light chain (MLC2) pathway were studied in vivo and in vitro to screen for potential molecular markers of CAS. We performed hematoxylin and eosin staining, myocardial zymogram, and transmission electron microscopy to determine myocardial and coronary artery injury in CAS rats. Then, using immunohistochemical staining, immunofluorescence staining, and Western blotting, we further demonstrated a potential molecular mechanism by which PKC regulated CAS via the CPI-17/MLC2 pathway. The results showed that membrane translocation of PKCα occurred in the coronary arteries of CAS rats. CPI-17/MLC2 signaling was observably activated in coronary arteries undergoing CAS. In addition, in vitro treatment of hCASMCs with angiotensin II (Ang II) increased PKCα membrane translocation while consistently activating CPI-17/MLC2 signaling. Conversely, GF-109203X and calphostin C, specific inhibitors of PKC, inactivated CPI-17/MLC2 signaling. We also collected the coronary artery tissues from deceased subjects suspected to have died of CAS and measured their levels of phosphorylated CPI-17 (p-CPI-17) and MLC2 (p-MLC2). Immunohistochemical staining was positive for p-CPI-17 and p-MLC2 in the tissues of these subjects. These findings suggest that PKCα induced CAS through the CPI-17/MLC2 pathway; therefore, p-CPI-17 and p-MLC2 could be used as potential markers for CAS. Our data provide novel evidence that therapeutic strategies against PKC or CPI-17/MLC2 signaling might be promising in the treatment of CAS.

A Case of Ventricular Fibrillation in Masked Long-QT Syndrome Coexisting with Coronary Vasospasm.

Although long-QT syndrome (LQTS) with a normal range QT interval at rest leads to fatal ventricular arrhythmias, it is difficult to diagnose. In this article, we present a rare case of a patient who suffered a cardiac arrest and was recently diagnosed with LQTS and coronary vasospasm. A 62-year-old man with no syncopal episodes had a cardiopulmonary arrest while running. During coronary angiography, vasospasm was induced and we prescribed coronary vasodilators, including calcium channel blockers. An exercise stress test was performed to evaluate the effect of medications and accidentally unveiled exercise-induced QT prolongation. He was diagnosed with LQTS based on diagnostic criteria. Pharmacotherapy and an implantable cardioverter defibrillator were used for his medical management. It is extremely rare for LQTS and coronary vasospasm to coexist. In cases of exercise-induced arrhythmic events, the exercise stress test might be helpful to diagnose underlying disease.

Ponatinib-Related Vasospastic Angina.

Tyrosine kinase inhibitors (TKIs) are essential drugs for chronic myeloid leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia. Cardiovascular or arteriothrombotic adverse events have been reported in patients treated with TKIs. We report 3 cases of Ponatinib-related vasospastic angina, in which prophylactic administration of nitrates or calcium channel blockers was effective.

Cardioprotective and Antianginal Efficacy of Nicorandil: A Comprehensive Review.

ABSTRACT: Angina pectoris remains a significant burden despite advances in medical therapy and coronary revascularization. Many patients (up to 30%) with angina have normal coronary arteries, with coronary microvascular disease and/or coronary artery vasospasm being major drivers of the myocardial demand-supply mismatch. Even among patients revascularized for symptomatic epicardial coronary stenosis, recurrent angina remains highly prevalent. Medical therapy for angina currently centers around 2 disparate goals, viz secondary prevention of hard clinical outcomes and symptom control. Vasodilators, such as nitrates, have been first-line antianginal agents for decades, along with beta-blockers and calcium channel blockers. However, efficacy in symptoms control is heterogenous, depending on underlying mechanism(s) of angina in an individual patient, often necessitating multiple agents. Nicorandil (NCO) is an antianginal agent first discovered in the late 1970s with a uniquely dual mechanism of action. Like a typical nitrate, it mediates medium-large vessel vasodilation through nitric oxide. In addition, NCO has adenosine triphosphate (ATP)-dependent potassium channel agonist activity (K ATP ), mediating microvascular dilatation. Hence, it has proven effective in both coronary artery vasospasm and coronary microvascular disease, typically challenging patient populations. Moreover, emerging evidence suggests that cardiomyocyte protection against ischemia through ischemic preconditioning may be mediated through K ATP agonism. Finally, there is now fairly firm evidence in favor of NCO in terms of hard event reduction among patients with stable coronary artery disease, following myocardial infarction, and perhaps even among patients with congestive heart failure. This review aims to summarize the mechanism of action of NCO, its efficacy as an antianginal, and current evidence behind its impact on hard outcomes. Finally, we review other cardiac and emerging noncardiac indications for NCO use.

Non-invasive diagnosis of vasospastic angina.

Vasospastic angina (VSA), or variant angina, is an under-recognized cause of chest pain and myocardial infarction, especially in Western countries. VSA leads to a declined quality of life and is associated with increased morbidity and mortality. Currently, the diagnosis of VSA relies on invasive testing that requires the direct intracoronary administration of ergonovine or acetylcholine. However, invasive vasoreactivity testing is underutilized. Several non-invasive imaging alternatives have been proposed to screen for VSA. This review aims to discuss the strengths and limitations of available non-invasive imaging tests for vasospastic angina.

Post-partum myocardial ischemia due to intramuscular methylergonovine-induced coronary vasospasm: case report.

BACKGROUND: Methylergonovine is a vasoconstrictive agent historically used as a provocative agent in the lab for coronary vasospasm; it is also a first line uterotonic agent for management of postpartum hemorrhage. CASE PRESENTATION: A 29-year-old female with history of smoking and idiopathic thrombocytopenia received intramuscular methylergonovine after delivery of twins for intrauterine hemorrhage management. Subsequently, she had episodes of chest pain with high sensitivity Troponin I elevation to 1509 ng/L with accompanying septal T wave inversions, decreased left ventricular ejection fraction to 49% and basal septal wall hypokinesis. Computed tomography (CT) coronary angiogram showed patent coronary arteries and no coronary arterial dissection. The patient was conservatively managed with aspirin and metoprolol, and on follow up had fully recovered left ventricular function with resolution of wall motion abnormalities. Given this, coronary vasospasm due to intramuscular methylergonovine is the most likely cause of patient's chest pain and associated myocardial ischemia. CONCLUSIONS: Intramuscular, intrauterine, intravenous, and even oral methylergonovine can rarely cause coronary vasospasm leading to myocardial ischemia. Cardiologists caring for postpartum patients should be aware of these potential lethal complications; prompt identification and administration of sublingual nitroglycerin can prevent severe complications of arrythmias, heart block, or cardiac arrest.

J wave dynamicity during coronary angiography and intracoronary acetylcholine administration.

BACKGROUND: J-waves may be observed during coronary angiography (CAG) or intracoronary acetylcholine (ACh) administration, but their significance is unknown. METHODS: Forty-nine patients, 59.1 ± 11.5 years old and 59% male, were studied on suspicion of vasospastic angina, and J wave dynamicity was compared between CAG and Ach administration. RESULTS: Diagnostic (≥0.1 mV) or nondiagnostic (<0.1 mV) J waves in 9 and 3 patients, respectively, were augmented, and J waves were newly observed in 2 patients during CAG and Ach administration. Similar changes in the J-wave amplitude were observed: from 0.10 ± 0.09 mV to 0.20 ± 0.15 mV (p < .002) and from 0.10 ± 0.10 mV to 0.20 ± 0.16 mV (p < .001) during CAG and Ach administration, respectively. J waves were located in the inferior leads and changed only during the right coronary interventions. In the remaining 35 patients, J waves were absent before and during the coronary interventions. Augmentation of J waves was found when the RR interval was shortened in some patients. Injection of anoxic media into the coronary artery might induce a conduction delay from myocardial ischemia that manifests as augmentation or new occurrence of J waves. CONCLUSIONS: Both CAG and intracoronary Ach administration affected J waves similarly in the same individuals. A myocardial ischemia-induced conduction delay may be responsible for the changes in J waves, but further studies are needed.

Prognostic impact of nitrate therapy in patients with myocardial bridge and coexisting coronary artery spasm.

The aim of this study was to investigate the prognostic impact of nitrate therapy in patients with myocardial bridge (MB) and coexisting coronary artery spasm (CAS). MB often accompanies CAS. Nitrates have been widely used as anti-ischemic drugs in CAS patients, while it is not recommended in MB patients. Thus, we investigated the long-term impact of nitrate on clinical outcomes in patients with both CAS and MB. A retrospective observational study was performed using propensity score matching (PSM) in a total of 757 consecutive MB patients with positive acetylcholine (Ach) provocation test. Patients were divided into two groups according to the regular administration of nitrates (nitrate group: n = 504, No nitrate group; n = 253). The PSM was used to adjust for selection bias and potential confounding factors, and major clinical outcomes were compared between the two groups up to 5 years. Baseline characteristics were well-matched between the two groups following PSM (n = 211 for both groups). There was no significant difference in the incidence of death, myocardial infarction, and major adverse cardiovascular events (MACEs) between the two groups. However, the nitrate group showed a significantly higher rate of recurrent angina which subsequently needed re-evaluation of coronary arteries by follow-up angiography (15.7 vs. 5.7%, Log-rank p = 0.012) compared to the non-nitrate group. Long-term nitrate administration in patients with MB and coexisting CAS did not show benefit in reducing MACE, rather it was associated with a higher incidence of recurrent angina requiring follow-up angiography.

Coronary artery spasm treated with intracoronary bioresorbable scaffold implantation under the guidance of treadmill test and optical coherence tomography: A case report.

Coronary artery spasm (CAS) can cause unstable angina, and the treatment of this disease is controversial. We report an elderly male patient who was admitted to hospital due to chest tightness. CAG showed that 70% stenosis in the middle of the right coronary artery (RCA). A bioresorbable scaffold (BRS) was implanted in the lesion under the guidance of optical coherence tomography (OCT). One year later, the patient's symptoms were relieved. The repeated CAG showed that the stent was good. BRS implantation under the guidance of treadmill test and OCT is one of treatment options for CAS patients.

Acute Coronary Spasm Following Pelvic Fracture, Bleeding, and Shock in a Trauma Patient.

We report a case of a patient with severe pelvic fracture who showed concurrent ST elevation on electrocardiogram. A 70-year-old man incurred an unstable pelvic fracture from a motorcycle accident. On admission, he was hemodynamically unstable, and massive transfusion and noradrenaline were administered immediately. Although ST elevation was present in leads II, III, aVF, V5, and V6, cardiac function was preserved; thus, trans-arterial embolization and external fixation for pelvic fracture were given priority. Four days after the injury, he suffered a cardiac arrest, and coronary angiography revealed that the cause of ST elevation and cardiac arrest was coronary vasospasm. Physicians should be aware that pain-related stress and platelet activation as well as use of noradrenaline in severe trauma cases can induce coronary vasospasm.

Kounis syndrome following allergy injection in a paediatric patient.

Kounis syndrome is the concurrence of acute coronary syndrome or coronary vasospasm with conditions associated with the release of inflammatory cytokines through mast cell activation in the setting of allergic or anaphylactic reactions. Many identified triggers have been identified in paediatric patients including exposures, drugs, and immunisations; however, to our knowledge this is the first case report of Kounis syndrome linked to immunotherapy. We present a case of a 9-year-old with seasonal allergies presenting with clinical symptoms of Kounis syndrome following her weekly subcutaneous injection of allergens. Clinicians need a high index of suspicion for Kounis syndrome in patients who develop systemic signs of anaphylaxis with clinical, laboratory, electrocardiographic, and echocardiographic findings of acute coronary syndrome to help direct therapy and improve outcomes.

Acute coronary syndrome due to multi-vessel coronary artery spasm in an Afghan refugee adolescent mimicking recurrent myocarditis.

Vasospastic angina is extremely uncommon for adolescents to experience chest discomfort, which is defined by transitory ST segment elevation or depression and angina symptoms that occur while at rest. It may result in potentially fatal conditions like myocardial infarction, ventricular fibrillation, or even sudden cardiac arrest. To aim of this article is to report a very rare case of a 17-year-old male Afghan refugee who was diagnosed with vasospastic angina after presenting with chest pain, and after receiving calcium channel blocker and nitrates for medical therapy, there were no angina attacks. Our case underlines the value of a thorough evaluation of adolescent's chest pain, the need to diagnose based on the symptoms, and the necessity of performing coronary angiography to rule out coronary causes when there is a high suspicion to a cardiac cause.

Coronary Artery Spasm-Related Heart Failure Syndrome: Literature Review.

Although heart failure (HF) is a clinical syndrome that becomes worse over time, certain cases can be reversed with appropriate treatments. While coronary artery spasm (CAS) is still underappreciated and may be misdiagnosed, ischemia due to coronary artery disease and CAS is becoming the single most frequent cause of HF worldwide. CAS could lead to syncope, HF, arrhythmias, and myocardial ischemic syndromes such as asymptomatic ischemia, rest and/or effort angina, myocardial infarction, and sudden death. Albeit the clinical significance of asymptomatic CAS has been undervalued, affected individuals compared with those with classic Heberden's angina pectoris are at higher risk of syncope, life-threatening arrhythmias, and sudden death. As a result, a prompt diagnosis implements appropriate treatment strategies, which have significant life-changing consequences to prevent CAS-related complications, such as HF. Although an accurate diagnosis depends mainly on coronary angiography and provocative testing, clinical characteristics may help decision-making. Because the majority of CAS-related HF (CASHF) patients present with less severe phenotypes than overt HF, it underscores the importance of understanding risk factors correlated with CAS to prevent the future burden of HF. This narrative literature review summarises and discusses separately the epidemiology, clinical features, pathophysiology, and management of patients with CASHF.

Effects of Soluble Guanylate Cyclase Stimulators and Activators on Anti-Aggregatory Signalling in Patients with Coronary Artery Spasm.

Impairment of the nitric oxide/soluble guanylate cyclase (NO)/sGC) signalling cascade is associated with many forms of cardiovascular disease, resulting not only in compromised vasodilatation but also loss of anti-aggregatory homeostasis. Myocardial ischaemia, heart failure, and atrial fibrillation are associated with moderate impairment of NO/sGC signalling, and we have recently demonstrated that coronary artery spasm (CAS) is engendered by severe impairment of platelet NO/sGC activity resulting in combined platelet and vascular endothelial damage. We therefore sought to determine whether sGC stimulators or activators might normalise NO/sGC homeostasis in platelets. ADP-induced platelet aggregation and its inhibition by the NO donor sodium nitroprusside (SNP), the sGC stimulator riociguat (RIO), and the sCG activator cinaciguat (CINA) alone or in addition to SNP were quantitated. Three groups of individuals were compared: normal subjects (n = 9), patients (Group 1) with myocardial ischaemia, heart failure and/or atrial fibrillation (n = 30), and patients (Group 2) in the chronic stage of CAS (n = 16). As expected, responses to SNP were impaired (p = 0.02) in patients versus normal subjects, with Group 2 patients most severely affected (p = 0.005). RIO alone exerted no anti-aggregatory effects but potentiated responses to SNP to a similar extent irrespective of baseline SNP response. CINA exerted only intrinsic anti-aggregatory effects, but the extent of these varied directly (r = 0.54; p = 0.0009) with individual responses to SNP. Thus, both RIO and CINA tend to normalise anti-aggregatory function in patients in whom NO/sGC signalling is impaired. The anti-aggregatory effects of RIO consist entirely of potentiation of NO, which is not selective of platelet NO resistance. However, the intrinsic anti-aggregatory effects of CINA are most marked in individuals with initially normal NO/sGC signalling, and thus their magnitude is at variance with extent of physiological impairment. These data suggest that RIO and other sGC stimulators should be evaluated for clinical utility in both prophylaxis and treatment of CAS.

Relationship between Inflammation and Vasospastic Angina.

Coronary artery spasm (CAS) is a dynamic coronary stenosis causing vasospastic angina (VSA). However, VSA is a potentially lethal medical condition with multiple presentations, including sudden cardiac death. Despite investigations to explore its pathogenesis, no single mechanism has been found to explain the entire process of VSA occurrence. The roles of elevated local and systemic inflammation have been increasingly recognized in VSA. Treatment strategies to decrease local and systemic inflammation deserve further investigation.

En mann i 50-årene med brystsmerter og synkope.

BACKGROUND: A man in his fifties with hypertension and no other previous health problems was admitted to the hospital after frequent episodes of retrosternal squeezing chest pain, and an episode of syncope. A recent computer tomography coronary angiography demonstrated normal coronary arteries with no atherosclerosis. CASE PRESENTATION: During admission, the patient developed several episodes of chest pain lasting five to fifteen minutes followed by non-sustained ventricular tachycardia, and initially no ST elevation in the electrocardiogram (ECG). He had normal findings on ECG and magnetic resonance imaging of the heart. During hospitalisation, ST elevations in the ECG were observed in relation to chest pain. Due to ST elevation, invasive coronary angiography was performed, revealing a suspected culprit lesion in the left anterior descending artery, treated with percutaneous coronary intervention (PCI). Despite PCI, he had persistent episodes of chest pain with ST elevation and non-sustained ventricular tachycardia. Vasospastic angina was suspected. INTERPRETATION: The clinical presentation is classical for vasospastic angina. After treatment with calcium channel blocker together with long-acting nitrate, there were no new episodes of chest pain or non-sustained ventricular tachycardia. Because of non-sustained ventricular tachycardia with haemodynamic instability and syncope, an implantable cardioverter-defibrillator was implanted.

Sex Difference in Coronary Artery Spasm Tested by Intracoronary Acetylcholine Provocation Test in Patients with Nonobstructive Coronary Artery Disease.

Introduction: Cardiovascular diseases manifest differently in men and women. The purpose of this study is to compare the sex difference in the characteristics of coronary artery spasm (CAS) in patients with nonobstructive cardiovascular disease (NOCVD) and the clinical outcomes in accordance with sex in CAS patients. Methods: The study analysed 5,491 patients with NOCVD who underwent an acetylcholine provocation test from November 2004 to May 2014 for evaluation of chest pain. CAS was defined as greater than 70% of luminal narrowing of the artery during the acetylcholine provocation test. Results: The patients were divided into men (n = 2,506) and women (n = 2,985). Mean follow-up days were 1,218 ± 577 days. To adjust for confounding factors, the propensity score matching (PSM) analysis was performed in all patients and among the CAS patients. After PSM analysis, a total of 1,201 pairs in all patients and a total of 713 pairs in CAS patients were generated. In all patients, women showed significantly less incidence of CAS compared with men (62.3% vs 50.9%, P < 0.01). Myocardial bridge (MB) and moderate stenosis were less prevalent in women, while transient ST elevation and ischemic chest pain during provocation were more frequent in women. In CAS patients, men had a higher incidence of multivessel spasm than women (35.7% vs. 29.7%, P < 0.01). Old age, dyslipidemia, and MB were independent risk factors of CAS in both men and women. In CAS patients, there was no statistical differences for various individual and composite major outcomes up to five years in either men or women. In men with CAS, old age was a risk factor of a 5-year major adverse cardiac event (MACE), and moderate stenosis was a risk factor of both 5-year MACE and 5-year recurrent angina. In women with CAS, mild stenosis was a risk factor of 5-year MACE, while myocardial bridge was a risk factor of 5-year recurrent angina. Conclusions: In this study, there were sex differences in the angiographic and clinical parameters during the acetylcholine provocation test, incidence of CAS, risk factors of CAS, 5-year MACE, and recurrent angina. Old age, dyslipidemia, and MB were independent risk factors of CAS in both sexes. However, major clinical outcomes up to five years in CAS patients were not different according to sex.

Definition and epidemiology of coronary microvascular disease.

Ischemic heart disease remains one of the leading causes of death and disability worldwide. However, most patients referred for a noninvasive computed tomography coronary angiogram (CTA) or invasive coronary angiogram for the investigation of angina do not have obstructive coronary artery disease (CAD). Approximately two in five referred patients have coronary microvascular disease (CMD) as a primary diagnosis and, in addition, CMD also associates with CAD and myocardial disease (dual pathology). CMD underpins excess morbidity, impaired quality of life, significant health resource utilization, and adverse cardiovascular events. However, CMD often passes undiagnosed and the onward management of these patients is uncertain and heterogeneous. International standardized diagnostic criteria allow for the accurate diagnosis of CMD, ensuring an often overlooked patient population can be diagnosed and stratified for targeted medical therapy. Key to this is assessing coronary microvascular function-including coronary flow reserve, coronary microvascular resistance, and coronary microvascular spasm. This can be done by invasive methods (intracoronary temperature-pressure wire, intracoronary Doppler flow-pressure wire, intracoronary provocation testing) and non-invasive methods [positron emission tomography (PET), cardiac magnetic resonance imaging (CMR), transthoracic Doppler echocardiography (TTDE), cardiac computed tomography (CT)]. Coronary CTA is insensitive for CMD. Functional coronary angiography represents the combination of CAD imaging and invasive diagnostic procedures.