Comparison of Baseline and Post-Nitrate Exercise Testing in Patients with Angina but Non-Obstructed Coronary Arteries with Different Acetylcholine Test Results

Background: Intracoronary acetylcholine testing may induce epicardial coronary artery spasm (CAS) or coronary microvascular spasm (CMVS) in patients with angina syndromes but non-obstructive coronary artery disease, but their causal role in individual patients is not always clear. In this prospective, observational single-center study, we aimed to assess whether (1) the induction of myocardial ischemia/angina by electrocardiogram (ECG) exercise stress test (EST) differs between patients showing different results in response to acetylcholine testing (i.e., CAS, CMVS, or no spasm); (2) the preventive administration of short-acting nitrates has any different effects on the EST of those patients who showed a positive basal EST. We expected that if exercise-induced angina and/or ischemic ECG changes are related to CAS, they should improve after nitrates administration, whereas they should not significantly improve if they are caused by CMVS. Methods: We enrolled 81 patients with angina syndromes and non-obstructive coronary artery disease, who were divided into three groups according to acetylcholine testing: 40 patients with CAS (CAS-group), 14 with CMVS (CMVS-groups), and 27 with a negative test (NEG-group). All patients underwent a basal EST (B-EST). Patients with a positive B-EST repeated the test 24-48 h later, 5 min after the administration of short-acting nitrates (N-EST). Results: There were no significant differences among the groups in terms of the B-EST results. B-EST was positive in eight (20%) patients in the CAS-group, seven (50%) in the CMVS-group, and six (22%) in the NEG-group (p = 0.076). N-EST, performed in eight, six, and five of these patients, also showed similar results in the three groups. Furthermore, the N-EST results also did not significantly differ compared to B-EST in any group, remaining positive in seven (87.5%), four (66.7%), and four (80%) patients in the CAS-group, CMVS-group, and NEG-group, respectively (p = 0.78). Conclusions: Our data show that patients with angina and non-obstructive coronary artery disease show largely comparable results of the ECG exercise stress test and similar poor effects of short-acting nitrates on abnormal ECG exercise stress test results. On the whole, our findings suggest caution in attributing to the results of Ach testing a definite causal role for the clinical syndrome in individual patients.

Chemokine Fractalkine and Non-Obstructive Coronary Artery Disease-Is There a Link?

Non-obstructive coronary artery disease (NO-CAD) constitutes a heterogeneous group of conditions collectively characterized by less than 50% narrowing in at least one major coronary artery with a fractional flow reserve (FFR) of ≤0.80 observed in coronary angiography. The pathogenesis and progression of NO-CAD are still not fully understood, however, inflammatory processes, particularly atherosclerosis and microvascular dysfunction are known to play a major role in it. Chemokine fractalkine (FKN/CX3CL1) is inherently linked to these processes. FKN/CX3CL1 functions predominantly as a chemoattractant for immune cells, facilitating their transmigration through the vessel wall and inhibiting their apoptosis. Its concentrations correlate positively with major cardiovascular risk factors. Moreover, promising preliminary results have shown that FKN/CX3CL1 receptor inhibitor (KAND567) administered in the population of patients with ST-elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI), inhibits the adverse reaction of the immune system that causes hyperinflammation. Whereas the link between FKN/CX3CL1 and NO-CAD appears evident, further studies are necessary to unveil this complex relationship. In this review, we critically overview the current data on FKN/CX3CL1 in the context of NO-CAD and present the novel clinical implications of the unique structure and function of FKN/CX3CL1 as a compound which distinctively contributes to the pathomechanism of this condition.

Coronary Tortuosity Index vs. Angle Measurement Method for the Quantification of the Tortuosity of Coronary Arteries in Non-Obstructive Coronary Disease

Coronary tortuosity has been recognized as a potential pathophysiological mechanism in the development of non-obstructive coronary artery disease (CAD). The aim of this study was to examine the role of two coronary tortuosity measurement methods in the detection of clinically significant coronary tortuosity. The study included 160 patients with angina symptoms and myocardial ischemia detected by cardiac stress tests in chronic settings and those diagnosed with acute coronary syndrome. After coronary angiography, tortuosity of coronary arteries was assessed by two methods, including measurement of tortuosity angles and calculating of tortuosity index. Significantly more tortuous coronary arteries were detected in the group with non-obstructive CAD (p < 0.01 for all three arteries), with significantly higher tortuosity index (TI) for all three coronary arteries in this group of patients, compared to patients with obstructive CAD. The highest TI for LCX was found in patients with lateral ischemia (p < 0.001) and for LAD in patients with anterior ischemia (p < 0.001). When measured by the angle method, the only association was found between LCX tortuosity and lateral ischemia (OR 4.9, p = 0.046). In conclusion, coronary tortuosity represents a pathophysiological mechanism for myocardial ischemia in non-obstructive CAD. The coronary tortuosity index could be a reliable and widely applicable tool for the quantification of coronary tortuosity.

Long-Term Clinical Impact of Patients with Multi-Vessel Non-Obstructive Coronary Artery Disease

BACKGROUND

Non-obstructive coronary artery disease (CAD) is a disease commonly diagnosed in patients undergoing coronary angiography. However, little is known regarding the long-term clinical impact of multi-vessel non-obstructive CAD. Therefore, the object of this study was to investigate the long-term clinical impact of multi-vessel non-obstructive CAD.

METHOD

A total of 2083 patients without revascularization history and obstructive CAD were enrolled between January 2010 and December 2015. They were classified into four groups according to number of vessels involved in non-obstructive CAD (25% ≤ luminal stenosis < 70%): zero, one, two, or three diseased vessels (DVs). We monitored the patients for 5 years. The primary outcome was major cardiovascular and cerebrovascular events (MACCEs), defined as a composite of cardiac death, stroke, and myocardial infarction (MI).

RESULT

The occurrence of MACCEs increased as the number of non-obstructive DVs increased, and was especially high in patients with three DVs. After adjustment, patients with three DVs still showed significantly poorer clinical outcomes of MACCEs, stroke, and MI compared those with zero DVs.

CONCLUSION

Multi-vessel non-obstructive CAD, especially in patients with non-obstructive three DVs, is strongly associated with poor long-term clinical outcomes. This finding suggests that more intensive treatment may be required in this subset of patients.

The Association of Severe Coronary Tortuosity and Non-Obstructive Coronary Artery Disease

Background and Objectives: There is an increasing interest in the coronary tortuosity as a novel pathophysiological mechanism of ischemia in coronary artery disease without significant obstruction, but there are a lack of studies to confirm this relationship in the clinical setting. The aim of our study was to evaluate the association of severe coronary tortuosity and the potential role of coronary blood supply dominance in the appearance of myocardial ischemia in patients with non-obstructive coronary artery disease (non-CAD), compared to patients with obstructive coronary artery disease (CAD). Materials and Methods: The study enrolled 131 participants (71 male and 60 female), recruited among patients referred to cardiologists due to angina symptoms with ischemic alterations established by cardiac stress tests, as well as those admitted to the hospital for acute coronary syndrome. Results: Mean age of recruited patients was 61.6 (±10.1) years. According to the coronary angiography, they were divided into two groups: non-obstructive and obstructive CAD (77 and 54, respectively). There were significantly more women (61% vs. 24%, p < 0.001) in the non-CAD group. Both tortuous coronary arteries (50.6% vs. 14.8%, p < 0.001) and left coronary dominance (37.7% vs. 16.7%, p = 0.006) were more frequent in the non-CAD group compared to the CAD group. Female sex (OR = 17.516, p = 0.001), tortuous coronary arteries (OR = 7.962, p = 0.006) and left dominance of blood supply were significant predictors for non-CAD. Conclusions: Non-obstructive CAD is common among patients, especially women, who are referred for coronary angiography. Severe coronary artery tortuosity is the strongest independent predictor of non-obstructive CAD, followed by female gender and left coronary dominance.

Non-obstructive CAD and Risk of All-cause Mortality in Middle-aged and Older Patients: a Nine-Year Follow-up and Multicentre Study

AIM

We aimed to examine all-cause mortality risk in relation to the extent of non-obstructive coronary artery disease (CAD) by coronary computed tomography angiography (CTA) in Chinese middle-aged and older patients in a multicenter study with nine-year follow-up.

METHODS

This was a retrospective, observational, multicentre study. The study population consisted of 3,240 consecutive middle-aged and older patients (age ≥ 40 years) with suspected CAD who underwent coronary CTA between June 2011 and December 2013 at three hospitals in Wuhan, China. Patients were grouped according to CAD extent for the final analysis: no CAD, 1-vessel non-obstructive CAD, 2-vessels non-obstructive CAD, and 3-vessels non-obstructive CAD. The primary endpoint was all-cause mortality. Kaplan-Meier method and Cox proportional hazards regression models were used for analysis.

RESULTS

A total of 2,522 patients were included in the present analysis. Of these, 188 (7.5%) deaths occurred during the median 9.0 years (interquartile range 8.6-9.4) of study follow-up. The annualized all-cause mortality rate was 0.54 (95% CI: 0.44-0.68), 0.91 (95% CI: 0.68-1.21), 1.44 (95% CI: 1.01-1.93), and 2.00 (95% CI: 1.46-2.69) for the no CAD, 1-vessel non-obstructive CAD, 2-vessels non-obstructive CAD, and 3-vessels non-obstructive CAD group, respectively. Kaplan-Meier survival curves showed a significant increase in the cumulative events associated with the extent of non-obstructive CAD (P < 0.001). In multivariate Cox regression, after adjustment for age and sex, the presence of 3-vessels non-obstructive CAD was a significant predictor of all-cause mortality (HR 1.60, 95% CI: 1.04-2.45, P = 0.032).

CONCLUSION

In this cohort of Chinese middle-aged and older patients undergoing coronary CTA, the presence and extent of non-obstructive CAD, compared to no CAD, were associated with a significantly greater nine-year risk of all-cause mortality. The present findings suggest the clinical importance of the stage of non-obstructive CAD and warrant investigation of the optimal risk stratification to improve outcomes among these patients.

Coronary Microvascular Dysfunction: Features and Prognostic Value

(1) Background: The results of the international studies support the assumption that coronary microvascular dysfunction (CMD) occurs significantly more often than previously identified and is associated with adverse outcomes. However, there is a lack of the accurate comprehension of its pathophysiology. The objectives of this study were to evaluate the clinical and instrumental features of CMD and to assess its prognostic value during 12 months of follow-up period. (2) Methods: A total of 118 patients with non-obstructive coronary artery disease (CAD) and preserved LV ejection fraction (62 [59; 64]%) were enrolled in the study. Serum levels of biomarkers were analyzed by enzyme-linked immunoassay. CMD was defined as the reduced myocardial flow reserve (MFR) ≤ 2 obtained by dynamic CZT-SPECT. Two-dimensional transthoracic echocardiography with evaluation of LV diastolic dysfunction was performed baseline. (3) Results: Patients were divided into groups depending on the presence of CMD: CMD+ group (MFR ≤ 2; n = 45), and CMD- group (MFR > 2; n = 73). In CMD+ group, the severity of diastolic dysfunction, the levels of biomarkers of fibrosis and inflammation were higher than in CMD- group. Multivariate regression analysis showed that the presence of diastolic dysfunction (OR 3.27; 95% CI 2.26-5.64; p < 0.001), the hyperexpression of NT-proBNP ≥ 760.5 pg/mL (OR 1.67; 95% CI 1.12-4.15; p = 0.021) and soluble ST2 ≥ 31.4 ng/mL (OR 1.37; 95% 1.08-2.98; p = 0.015) were independent factors associated with CMD. Kaplan-Meier analysis showed that a rate of the adverse outcomes was significantly (p < 0.001) higher in patients with CMD (45.2%, n = 19) than in patients without it (8.6%, n = 6). (4) Conclusions: Our data suggest that the presence of CMD was associated with the severe diastolic dysfunction and hyperexpression of the biomarkers of fibrosis and inflammation. Patients with CMD had higher rate of the adverse outcomes than those without it.

The Atherosclerosis Profile by Coronary Computed Tomography Angiography (CTA) in Symptomatic Patients with Coronary Artery Calcium Score Zero

(1) Background: Whether it is safe to exclude coronary artery disease (CAD) in symptomatic patients with coronary artery calcium score (CACS 0), is an open debate. To compare coronary CTA including high-risk plaque (HRP) features in symptomatic patients with CACS 0 (2) Methods: 1709 symptomatic patients (age, mean 57.5 ± 16 years, 39.6% females) referred to coronary CTA for clinical indications were included. CACS, coronary stenosis (CADRADS) severity and HRP features (low-attenuation-plaque, spotty calcification, positive remodeling, NRS) were recorded. (3) Results: Of 1709 patients, 665 with CACS 0 were finally included. 562 (84.5%) had no CAD by CTA while 103 of 665 (15.4%) had CAD. Stenosis was minimal <25% in 79, mild <50% in 20, moderate in 1 and severe >70% in 3 patients. The rate of obstructive CAD was low with 4/665 (0.61%). The majority of patients had non-obstructive CAD (<50% stenosis) (99/103; 96.1%). A high proportion of patients with non-obstructive CAD had at least one HRP (52/103; 50.4%) per patient. (4) Conclusions: The rate of obstructive CAD is very low in symptomatic patients with CACS 0, and non-obstructive CAD domineering. CACS 0 does not rule out non-obstructive CAD and misses patients in which primary preventive measures are indicated. More than half of patients with non-obstructive CAD had high-risk plaque, highlighting the importance of quantitative plaque analysis.

D-Dimer Is Associated With Coronary Microvascular Dysfunction in Patients With Non-obstructive Coronary Artery Disease and Preserved Ejection Fraction

BACKGROUND

Coronary microvascular dysfunction (CMVD), an important etiology of ischemic heart disease, has been widely studied. D-dimer is a simple indicator of microthrombosis and inflammation. However, whether an increase in D-dimer is related to CMVD is still unclear.

MATERIALS AND METHODS

This retrospective study consecutively enrolled patients with myocardial ischemia and excluded those with obstructive coronary artery. D-dimer was measured at admission and the TIMI myocardial perfusion grade (TMPG) was used to distinguish CMVD. Patients were divided into the two groups according to whether the D-dimer was elevated (>500 ng/ml). Logistic models and restricted cubic splines were used to explore the relationship between elevated D-dimer and CMVD.

RESULTS

A total of 377 patients were eventually enrolled in this study. Of these, 94 (24.9%) patients with CMVD had older age and higher D-dimer levels than those without CMVD. After full adjustment for other potential clinical risk factors, patients with high D-dimer levels (>500 ng/ml) had a 1.89-times (95% CI: 1.09-3.27) higher risk of CMVD than patients with low D-dimer levels. A non-linear relationship was found between concentrations of D-dimer and CMVD. With increased D-dimer level, the incidence of CMVD increased and then remained at a high level. Stratified analysis was performed and showed similar results.

CONCLUSION

Elevated D-dimer level is associated with the incidence of CMVD and potentially serves as a simple biomarker to facilitate the diagnosis of CMVD for patients with angina.

Risk Factors Predisposing to Angina in Patients with Non-Obstructive Coronary Arteries: A Retrospective Analysis

No hemodynamically significant atherosclerotic plaques are observed in up to 30% of patients reporting angina and undergoing coronary angiography. To investigate risk factors associated with non-obstructive coronary artery disease (NOCAD), we analyzed the medical records of, consecutively, 136 NOCAD subjects and 128 patients with significant stenosis in at least one coronary artery (the OCAD group). The blood concentrations of the TC (4.40 [3.78−5.63] mmol/L vs. 4.12 [3.42−5.01] mmol/L; p = 0.026), LDL-C (2.32 [1.80−3.50] mmol/L vs. 2.10 [1.50−2.70] mmol/L; p = 0.003), non-HDL-C (2.89 [2.29−4.19] mmol/L vs. 2.66 [2.06−3.39] mmol/L; p = 0.045), as well as the LDL-C/HDL-C ratio (1.75 [1.22−2.60] vs. 1.50 [1.10−1.95]; p = 0.018) were significantly increased in the NOCAD patients compared to the OCAD group due to the lower prevalence and intensity of the statin therapy in the NOCAD individuals (p < 0.001). Moreover, the abovementioned lipid parameters appeared to be valuable predictors of NOCAD, with the LDL-C (OR = 1.44; 95%CI = 1.14−1.82) and LDL-C/HDL-C (OR = 1.51; 95%CI = 1.13−2.02) showing the highest odds ratios. Furthermore, multivariable logistic regression models determined female sex as the independent risk factor for NOCAD (OR = 2.37; 95%CI = 1.33−4.20). Simultaneously, arterial hypertension substantially lowered the probability of NOCAD (OR = 0.21; 95%CI = 0.10−0.43). To conclude, female sex, the absence of arterial hypertension, as well as increased TC, LDL-C, non-HDL, and LDL-C/HDL-C ratio are risk factors for NOCAD in patients reporting angina, potentially as a result of poor hypercholesterolemia management.

Lesion characteristics and prognosis of acute coronary syndrome without angiographically significant coronary artery stenosis

AIMS

While patients with acute coronary syndrome (ACS) presenting with non-obstructive coronary artery disease (CAD) are at high risk for cardiovascular mortality and morbidity, detailed lesion characteristics are unclear. The aim of this study was to investigate the lesion characteristics and prognosis of ACS with non-obstructive CAD.

METHODS AND RESULTS

This study consisted of 82 consecutive ACS patients without obstructive CAD who underwent optical coherence tomography (OCT). Based on the presence of high-risk lesions (HL) in the culprit artery, we classified the patients into two groups: HL group and non-high-risk lesions (NHL) group. A systematic clinical follow-up was performed at our outpatient clinic for up to 24 months. Our endpoint was recurrence of ACS with obstructive CAD. OCT revealed that 42 (51.2%) of 82 patients had hidden HL in the culprit artery, including ruptured plaque (15.9%), calcified nodule (11.0%), spontaneous coronary artery dissection (8.5%), lone thrombus (8.5%), thin-cap fibroatheroma (6.1%), and plaque erosion (1.2%). During angiography, 5 (11.9%) HL patients complained of chest pain without ST elevation. Patients in the HL group had poorer prognoses than those in the other groups (P = 0.040).

CONCLUSION

Hidden high-risk lesions accompany ACS patients without obstructive CAD, resulting in poorer outcomes. Vascular injury itself might provoke acute chest pain.

What an Interventionalist Needs to Know About MI with Non-obstructive Coronary Arteries

MI with non-obstructive coronary arteries (MINOCA) is caused by a heterogeneous group of vascular or myocardial disorders. MINOCA occurs in 5.15% of patients presenting with acute ST-segment elevation MI or non-ST segment elevation MI and prognosis is impaired. The diagnosis of MINOCA is made during coronary angiography following acute MI, where there is no stenosis ≥50% present in an infarct-related epicardial artery and no overt systemic aetiology for the presentation. Accurate diagnosis and subsequent management require the appropriate utilisation of intravascular imaging, coronary function testing and subsequent imaging to assess for myocardial disorders without coronary involvement. Although plaque-related MINOCA is currently managed with empirical secondary prevention strategies, there remains an unmet therapeutic need for targeted and evidence-based therapy for MINOCA patients and increased awareness of the recommended diagnostic pathway.

Red Blood Cell Morphodynamics: A New Potential Marker in High-Risk Patients

In the last years, a substantial contribution of red blood cells (RBCs) in cardiovascular homeostasis has been evidenced, as these cells are able to regulate cardiovascular function by the export of adenosine triphosphate and nitric oxide as well as to maintain redox balance through a well-developed antioxidant system. Recently a link between high-risk plaque (HRP) features and myocardial ischemia, in the absence of severe lumen stenosis, has been evidenced. Nonobstructive coronary artery disease (nonob CAD) has been associated in fact with a greater 1-year risk of myocardial infarction and all-cause mortality compared with no apparent CAD. This new evidence increases interest in searching new triggers to identify these high-risk patients, in the absence/or on top of traditional hazard markers. In this study, we investigated the existence of any association between RBC morphodynamics and HRP features in individuals with different grades of coronary stenosis detected by coronary computed tomography angiography (CCTA). Ninety-one consecutive individuals who underwent CCTA [33 no CAD; 26 nonobstructive (nonob), and 32 obstructive (ob) CAD] were enrolled. RBC morphodynamic features, i.e., RBC aggregability and deformability, were analyzed by means of Laser Assisted Optical Rotation Cell Analyzer (LoRRca MaxSis). The putative global RBC morphodynamic (RMD) score and the related risk chart, associating the extent of HRP (e.g., the non-calcified plaque volume) with both the RMD score and the max % stenosis were computed. In nonob CAD group only positive correlations between RBC rigidity, osmotic fragility or aggregability and HRP features (plaque necrotic core, fibro-fatty and fibro-fatty plus necrotic core plaque volumes) were highlighted. Interestingly, in this patient cohort three of these RBC morphodynamic features result to be independent predictors of the presence of non-calcified plaque volume in this patients group. The risk chart created shows that only in nonob CAD plaque vulnerability increases according to the score quartile. Findings of this work, by evidencing the association between erythrocyte morphodynamic characteristics assessed by LoRRca and plaque instability in a high-risk cohort of nonob CAD, suggest the use of these blood cell features in the identification of high-risk patients, in the absence of severe coronary stenosis.

Girl Who Cried Wolf: A Case of Prinzmetal Angina With Related ST-Elevation Myocardial Infarction

Prinzmetal variant angina is characterized by episodic chest pain associated with transient ST changes seen on an electrocardiogram (EKG). A 51-year-old female with a pertinent history of non-obstructive coronary artery disease (CAD), non-ST elevation myocardial infarction (NSTEMI) twice, ST-elevation myocardial infarction (STEMI), Prinzmetal angina, ventricular tachycardia s/p implantable cardioverter-defibrillator placement, and gastroesophageal reflux disease presented with 2.5 hours of left-sided chest pain with radiation to the left arm. Her initial EKG was not revealing. However, a subsequent EKG showed ST elevations in the inferior leads. A coronary angiogram was performed and revealed distal right coronary artery spasm that was relieved with intracoronary nitroglycerin. The nature of her chest pain in conjunction with her EKG and angiogram findings helped diagnose her with Prinzmetal angina that was significant enough to result in a STEMI. Thus, Prinzmetal angina and STEMI can be interconnected rather than being separate, mutually exclusive pathologies.

The effect of Shexiang Tongxin Dropping Pills on coronary microvascular dysfunction (CMVD) among those with a mental disorder and non-obstructive coronary artery disease based on stress cardiac magnetic resonance images: A study protocol

INTRODUCTION

Coronary microvascular dysfunction (CMVD), highly prevalent among patients with a mental disorder (anxiety or depression), is closely related to adverse cardiac events, including hospitalization, sudden cardiac death, and myocardial infarction. Shexiang Tongxin Dropping Pills (STDP), a traditional Chinese medicine, exerts endothelial protective function by anti-inflammation, anti-oxidative stress, and promoting blood circulation. STDP protects against CMVD in previous fundamental studies. The present trial is aiming at evaluating the effect of STDP on CMVD among depressed or anxious patients with non-obstructive coronary artery disease (NOCAD).

METHODS AND ANALYSIS

Seventy-two depressed or anxious patients diagnosed with NOCAD combined with CMVD utilizing coronary artery angiography and stress cardiac magnetic resonance (CMR) will be recruited in the present study. These patients will be randomized into two groups, namely, Nicorandil group (Nicorandil combined with routine medicine), and STDP groups (STDP combined with routine medicine). The change of CMVD status by assessing absolute myocardial blood flow and myocardial reperfusion using stress CMR 3-month after discharge is defined as the primary endpoint. Major adverse cardiac events (MACEs), quality of life (QOL), and metal disorder improvement are defined as the secondary endpoints. Seattle angina questionnaire (SAQ) which is used to assess angina pectoris and QOL will be recorded at 1-, 3-, 6-, 9-, 12-month of follow-up. Seven-item Generalized Anxiety Disorder Scale (GAD-7) and 9-item depression module from the Patient Health Questionnaire (PHQ9) which utilized to evaluate anxiety and depression, respectively, will be recorded at 1-, 3-, 6-, 9-, 12-month of follow-up. This study will first evaluate the efficacy of STDP on CMVD among patients with a mental disorder and NOCAD, and discuss the potential mechanisms, providing therapeutic evidence for the STDP for these patients.

Effects of Statin Treatment on Patients with Angina and Normal or Nearly Normal Angiograms

This article offers an updated and comprehensive overview of major findings on the effects of statin treatment in patients with chronic angina but without any epicardial coronary artery with obstructive lesion.

Relation of vascular dilator function and cardiac autonomic function with coronary angiography findings in patients with non-ST segment elevation acute coronary syndrome

BACKGROUND

A sizeable number of patients with a diagnosis of non-ST segment elevation acute coronary syndrome show non-obstructive coronary artery disease. In this study we assessed whether differences in vascular and cardiac autonomic function exist between non-ST segment elevation acute coronary syndrome patients with obstructive or non-obstructive coronary artery disease.

METHODS AND RESULTS

Systemic endothelium-dependent and independent vascular dilator function (assessed by flow-mediated dilation and nitrate-mediated dilation of the brachial artery, respectively) and cardiac autonomic function (assessed by time-domain and frequency-domain heart rate variability parameters) were assessed on admission in 120 patients with a diagnosis of non-ST segment elevation acute coronary syndrome. Patients were divided into two groups according to coronary angiography findings: (a) 59 (49.2%) with obstructive coronary artery disease (≥50% stenosis in any epicardial arteries); (b) 61 (50.8%) with non-obstructive coronary artery disease. No significant differences between the two groups were found in both flow-mediated dilation (5.03 ± 2.6 vs. 5.40 ± 2.5%, respectively; P = 0.37) and nitrate-mediated dilatation (6.79 ± 2.8 vs. 7.30 ± 3.4%, respectively; P = 0.37). No significant differences were also observed between the two groups both in time-domain and frequency-domain heart rate variability variables, although the triangular index tended to be lower in obstructive coronary artery disease patients (30.2 ± 9.5 vs. 33.9 ± 11.6, respectively; P = 0.058). Neither vascular nor heart rate variability variables predicted the recurrence of angina, requiring emergency room admission or re-hospitalisation, during 11.3 months of follow-up.

CONCLUSIONS

Among patients admitted with a diagnosis of non-ST segment elevation acute coronary syndrome we found no significant differences in systemic vascular dilator function and cardiac autonomic function between those with obstructive coronary artery disease and those with non-obstructive coronary artery disease.

A Rare Case of Vasospastic Angina Presenting with Inferior Lead ST-segment Elevation and Ventricular Fibrillation in the Absence of Coronary Obstruction: A Case Report

Vasospastic angina (VSA) is a variant form of angina pectoris, which occurs at night or at rest, with transient electrocardiogram modifications and preserved exercise capacity. Its association with stable angina, sudden cardiac death, acute coronary syndrome, arrhythmia, and syncope has previously been established. Its presentation can occur with or without existing coronary artery disease and may present with focal or diffuse alteration and dysfunction of the coronary vasculature. VSA diagnosis involves patient response to nitrates, transient ischemic electrocardiogram (ECG) changes, and coronary artery spasms. The mechanisms proposed to constitute the substrate for susceptibility to VSA include vascular smooth muscle cell hyperreactivity, endothelial dysfunction, magnesium deficiency, low-grade inflammation, altered autonomic nervous system response, hypothyroidism, and oxidative stress. Herein, we present the rare case of a patient with ST-segment elevation in the inferior leads, increased troponin, and an episode of ventricular fibrillation initially thought to be due to lateral wall ST-elevation myocardial infarction (STEMI), although it was revealed to be vasospastic angina. We will also review the literature. Vasospastic angina remains underdiagnosed and a timely diagnosis is crucial to prevent major cardiac events. In patients with diffuse ST-segment elevation on ECG (independently of angiographic findings), VSA should be considered as one of the differential diagnoses and treated if found to be the cause of pathological changes.

Impact of aortic stiffness on myocardial ischaemia in non-obstructive coronary artery disease

Objective

High aortic stiffness may reduce myocardial perfusion pressure and contribute to development of myocardial ischaemia. Whether high aortic stiffness is associated with myocardial ischaemia in patients with stable angina and non-obstructive coronary artery disease (CAD) is less explored.

Methods

Aortic stiffness was assessed as carotid-femoral pulse wave velocity (PWV) by applanation tonometry in 125 patients (62±8 years, 58% women) with stable angina and non-obstructive CAD participating in the Myocardial Ischemia in Non-obstructive CAD project. PWV in the highest tertile (>8.7 m/s) was taken as higher aortic stiffness. Stress-induced myocardial ischaemia was detected as delayed myocardial contrast replenishment during stress echocardiography, and the number of left ventricular (LV) segments with delayed contrast replenishment as the extent of ischaemia.

Results

Patients with higher aortic stiffness were older with higher LV mass index and lower prevalence of obesity (all p<0.05), while angina symptoms, sex, prevalence of hypertension, diabetes, smoking or LV ejection fraction did not differ between groups. Stress-induced myocardial ischaemia was more common (73% vs 42%, p=0.001) and the extent of ischaemia was larger (4±3 vs 2±3 LV segments, p=0.005) in patients with higher aortic stiffness. In multivariable logistic regression analysis, higher aortic stiffness was associated with stress-induced myocardial ischaemia independent of other known covariables (OR 4.74 (95% CI 1.51 to 14.93), p=0.008).

Conclusions

In patients with stable angina and non-obstructive CAD, higher aortic stiffness was associated with stress-induced myocardial ischaemia. Consequently, assessment of aortic stiffness may add to the diagnostic evaluation in patients with non-obstructive CAD.

Trial registration number

NCT01853527.

Clinical care for patients with recurrent myocardial ischemia in Germany-the VOICES trial

Background

Chronic ischemic heart disease is frequent and represents the most common cause of death in western countries. Angina pectoris, the clinical symptom of myocardial ischemia, is associated with increased morbidity and mortality also in patients without obstructive coronary artery disease. The aim of this study was to investigate the current care of patients with recurrent myocardial ischemia after ruling out significant coronary stenosis in the setting of outpatient care.

Methods

Data were obtained by a detailed and structured survey. German cardiologists in outpatient care were interviewed about the management and treatment of outpatients with recurrent angina pectoris after ruling out significant stenoses by coronary angiography. Items were analysed using rating scales [1-10] by means of descriptive methods. Absolute and relative frequency distribution was calculated for the characterisation of qualitative data and multiple-choice questions.

Results

The interviews of 731 cardiologic experts could be included in this analysis. The main results showed that history taking seems to be one major problem in those patients-more than 10% of the expert cardiologists admit that they do not perform a detailed history taking of patients with recurrent angina pectoris. While a classification of the symptoms by means of the CCS classification is rated as important such a classification is not used on a regular basis. Extra-cardiac causes are frequently not excluded before performing coronary angiography (>10% of the cases). A significant fraction (20%) of German cardiologists does not consider the initiation of a specific, antianginal medical treatment as their objective.

Conclusions

The trial revealed deficiencies in the history taking, the proper classification of the symptoms, and the initiation of an adequate drug therapy in patients with recurrent angina pectoris after exclusion of significant coronary stenoses.

Editor's Choice- Pathophysiology, diagnosis and management of MINOCA: an update

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a syndrome with different causes, characterised by clinical evidence of myocardial infarction with normal or near-normal coronary arteries on angiography. Its prevalence ranges between 5% and 25% of all myocardial infarction. The prognosis is extremely variable, depending on the cause of MINOCA. The key principle in the management of this syndrome is to clarify the underlying individual mechanisms to achieve patient-specific treatments. Clinical history, electrocardiogram, cardiac enzymes, echocardiography, coronary angiography and left ventricular angiography represent the first level diagnostic investigations to identify the causes of MINOCA. Regional wall motion abnormalities at left ventricular angiography limited to a single epicardial coronary artery territory identify an 'epicardial pattern'whereas regional wall motion abnormalities extended beyond a single epicardial coronary artery territory identify a 'microvascular pattern'. The most common causes of MINOCA are represented by coronary plaque disease, coronary dissection, coronary artery spasm, coronary microvascular spasm, Takotsubo cardiomyopathy, myocarditis, coronary thromboembolism, other forms of type 2 myocardial infarction and MINOCA of uncertain aetiology. This review aims at summarising the diagnosis and management of MINOCA, according to the underlying physiopathology.

Incidence and characteristics of patients presenting with acute myocardial infarction and non-obstructive coronary artery disease

OBJECTIVES

This study aimed to characterize the etiologies of patients presenting with myocardial infarction (MI) and found to have non-obstructive coronary artery disease (NOCAD) and compare risk factors and in-hospital mortality to those with obstructive coronary artery disease (CAD).

BACKGROUND

Patients presenting with an MI are often found to have NOCAD defined as less than 50% luminal diameter reduction by visual estimation on coronary angiography.

METHODS

This study is a retrospective analysis of a total of 2,038 patients that presented to NorthShore University HealthSystem with MI and underwent coronary angiography from 2010 to 2013.

RESULTS

1,822 patients (89%) had CAD and 216 (11%) had NOCAD. Of the NOCAD patients, the most common etiologies were Takotsubo cardiomyopathy (28%), no alternative explanation (26%), demand ischemia (21%), myopericarditis (7%), coronary artery vasospasm (5%), and coronary artery dissection (3%). NOCAD patients were more likely to be younger and female. There was no significant difference between NOCAD and CAD patients in terms of in-hospital mortality (3.7% vs. 4.0% respectively, OR = 1.1, 95% CI 0.5-2.3, P = 0.83 by univariate logistic regression, OR = 1.2, 95% CI 0.5-3.1, P = 0.74 by multivariable analysis).

CONCLUSIONS

CAD patients were more likely to have traditional risk factors of diabetes, hypertension, hypercholesterolemia, previous MI, previous revascularization with percutaneous coronary intervention or coronary artery bypass graft surgery. Patients presenting with MI and NOCAD were found to have several different etiologies on coronary angiography with the most common being Takotsubo cardiomyopathy.