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Objectives We assessed the relationship between exposure to air pollutants and mechanisms of coronary instability evaluated by optical coherence tomography (OCT) in patients with acute coronary syndrome (ACS). Background Air pollution is an emerging key player in determining the residual risk of coronary events. However, pathophysiological mechanisms linking air pollution and coronary events have been not adequately investigated. Methods Patients with ACS undergoing OCT imaging were retrospectively selected. Mechanism of culprit lesion instability was classified as plaque rupture (PR) or intact fibrous cap (IFC) by OCT, and the presence of macrophage infiltrates (MOI) and thin-cap fibroatheroma (TCFA) at the culprit site was also assessed. Based on each case’s home address, exposure to several pollutants was evaluated, including particulate matter 2.5 (PM2.5), PM10, and carbon monoxide (CO). Only patients with >2 years of available data on air pollution exposure prior to ACS were enrolled. Results We included 126 patients (median age: 67.0 years of age; interquartile range: 55.5-76.0; 97 male patients [77.0%]). Sixty-six patients (52.4%) had PR as the mechanism of plaque instability. Patients with PR were exposed to significantly higher PM2.5 levels than to IFC, and PM2.5 was independently associated with PR (odds ratio: 1.194; 95% CI: 1.036 to 1.377; P = 0.015). Moreover, exposure to higher levels of PM2.5 was independently associated with the presence of TCFA and of MOI at the culprit site. Interestingly, PM2.5, PM10, and C o levels were positively and significantly correlated with serum levels of C-reactive protein. Conclusions We provide novel insights into the missing link between air pollution and increased risk of coronary events. In particular, exposure to higher concentrations of air pollutants is associated with the presence of vulnerable plaque features and with plaque rupture as a mechanism of coronary instability. An enhanced systemic and plaque inflammatory activation may explain these findings.

Approximately half of the patients presenting with ST-segment elevation myocardial infarction have also significant atherosclerotic disease affecting coronary segments other than the infarct-related artery. Optimal management of residual lesions in this clinical setting has been a topic of intense research in the last decade. On the one hand, a large body of evidence has consistently shown the benefit of complete revascularization for the reduction of adverse cardiovascular outcomes. On the other hand, some crucial aspects such as the optimal timing or the best strategy of the complete treatment approach remain a matter of controversy. In this review, we aim to provide a thorough critical appraisal of the available literature regarding this topic, by discussing areas of relative certainty, gaps in the knowledge, approach to specific clinical subsets and future research directions.

Background Acute coronary syndrome (ACS) is the main cause of mortality worldwide and despite the adherence to guidelines it is still burdened by an unacceptable risk for cardiovascular (CV) events recurrence, highlighting the need to identify other than traditional cardiovascular risk factors (CVrF) implicated in atherosclerotic plaque instability. In this regard, psychosocial stress appears to be a crucial player in the development of CV disease. Nevertheless, stress is not easy to standardize and the mechanisms by which it promotes coronary artery disease (CAD) are poorly understood. Materials and Methods We therefore prospectively enrolled patients with ACS, stable coronary artery disease (CAD) undergoing percutaneous coronary intervention (PCI) and subjects presenting traditional CVrF but without established CV disease. Multimodality cortisol assessment, expression of acute and chronic stress, through blood, urine and hair samples collection was ascertained at baseline. A regression analysis was performed to assess the relationships between significant variables at univariate analysis. Results Fifty patients were enrolled in the present study. Cortisol levels in blood and urine were numerically higher in patients with ACS compared to CAD patients and subjects with traditional CVrF only. Hair cortisol levels did not differ between the three groups. The regression analysis showed an inverse correlation (R= -,532, p Conclusion The preliminary results of our study showed that patients with ACS did not have significantly higher levels of hair cortisol compared to stable patients. The finding of an inverse relationship between higher UC, UC/C ratio levels and lower LVEF values support a link between a hyperactivity of the hypothalamic-pituitary-adrenal axis and a worse ACS presentation. These preliminary data will be implemented with serial multimodality assessment of cortisol that allow potential implications in diagnosis and outcome.

Introduction Cardiac arrest secondary to a spontaneous coronary artery dissection (SCAD) represents a challenging scenario. It deserves specific considerations due to the dramatic presentation and the need for secondary sudden cardiac death prevention. Methods We collected clinical data of four women admitted during the last two years in the Coronary Care Unit of Parma University Hospital, whose presentation of SCAD were cardiac arrest due to ventricular fibrillation. Results Three patients survived the acute phases. One patient, being considered at high risk of SCAD recurrence, received a subcutaneous implantable cardioverter-defibrillator (S-ICD). Acute management of cardiac arrest related to SCAD deserves specific considerations. Our case series illustrates the importance of prompt resuscitation manoeuvres and early defibrillation. We propose a flow chart of management of cardiac arrest in patient with suspect of SCAD. Evaluating risk of SCAD recurrence and sudden cardiac death The management of SCAD patients complicated by malignant ventricular arrhythmias and cardiac arrest is challenging. Looking at published registries, it appears that SCAD patients are more likely to suffer from ventricular arrythmia or sudden cardiac death than non-SCAD MI patients. The risk-benefit ratio of ICD implantation in these patients remain uncertain . Evaluation of scar burden with CMR can help stratify the global arrhythmic risk, especially as extensive myocardial scar with a residual impaired LVEF increases the risk of future arrhythmic events. In our series, only one patient underwent S-ICD implantation, and the decision was mainly driven by the finding of underlying arteriopathy affecting other vascular territories, suggesting a potentially higher rate of SCAD recurrence. For this particular subset of patients, we propose an algorithm that combines predisposing factors and myocardia injury quantification data that could be useful for the estimate of the risk of malignant arrythmias, as well as the risk of recurrence of SCAD, but needs to be validated in larger case studies. Conclusions The acute management of cardiac arrest related to SCAD deserves specific consideration. The residual myocardial damage, predisposing and precipitants factors should be evaluated in order to estimate the SCAD recurrence and sudden cardiac death risks.

Background Transcatheter patent foramen ovale (PFO) closure is an effective therapy in patients with cryptogenic stroke (CS) or transient ischemic attack (TIA) and evidence of PFO. However, the incidence of recurrent cerebral ischemia is not negligible and underlying pathogenic mechanisms remain largely unknown. We sought to evaluate the magnitude of the problem and to assess predictors of recurrent stroke/TIA after transcatheter PFO closure. Methods We enrolled non-randomized consecutive patients who underwent PFO closure for secondary prevention of neurological ischemic events at the University Hospital of Parma between 2004 and 2021. Clinical, echocardiographic and procedure-related features were collected for each patient. The incidence of recurrent ischemic neurological events was assessed at follow-up. Results We enrolled a total of 154 patients. The primary indication for PFO closure was previous stroke (85 [55.2%] subjects) and a third of patients (51 [33.1%]) suffered from migraine, 22 [14.3%] with and 29 [18.8%] without aura. Moreover, mean Risk of Paradoxycal Embolism (ROPE) score at hospital admission was 6.4 ± 1.5. After a median follow-up of 112 months, the incidence of recurrent cerebral ischemia occurred in 13 [8.4%] patients, with an annualized rate of 0.92/100 patients. The presence of migraine, obesity and ROPE < 7 were independent positive predictors of recurrent stroke/TIA. Conclusion The presence of obesity, a familiar history of CVD, ROPE < 7 and migraine were independent positive predictors of recurrent ischemic neurological events after PFO closure.

Background ST-segment elevation myocardial infarction (STEMI) is one of the world's leading causes of disability and death. The incidence of late-onset STEMI (i.e. after at least 12 hours from symptom onset to medical observation) accounts up to 10% of overall STEMI events and optimal management in this setting is still debated due to the lack of randomized data. The aim of the present study is to explore the usefulness of FDG-PET to improve late-onset STEMI treatment. Methods We conducted a single-center retrospective observational study that included patients admitted for late-onset STEMI who underwent coronary angiography and FDG-PET to evaluate myocardial viability (MV). Follow-up by telephone interview and / or clinical follow-up at 6, 12, 24, 36, 48 and 60 months was performed in all patients. The prevalence of myocardial viability (MV) related to infarct-related artery (IRA) by FDG-PET study (using a semi-quantitative visual scoring method), the study of clinical and angiographic predictors of viability and the association of myocardial viability evaluated with FDG-PET with the improvement of the left ventricular ejection fraction (LVEF) were investigated. Results A total of 27 patients with mean age 64.7 ± 11.1 years, predominantly men (n=25, 92,6%), were enrolled in the study. Compared to patients without MV (n=12), MV-patients (n=15) presented more frequently dyslipidemia (100.0% vs 66.7%, p=0.015) and diabetes (53.3% vs 16.5%, p=0.050) but showed no difference in inflammatory biomarkers and echocardiographic parameters. Multivessel disease (MVD 86.7% vs 33.3%, p=0.004) and high-grade collateral-connection (hg-CC 80.0% vs 33.3%, p=0.027) were more frequent in MV-patients compared to patients without MV. The presence of angiographically visible hg-CC (OR=8.00, 95%CI 1.40-45.76, p=0.019) and MVD (OR=13.00, 95%CI 1.92-88.00, p Conclusions This study could be of great help in clinical practice in order to provide a personalized approach in patients with late-STEMI, suggesting the potential benefit of a routine assessment IRA-related viability by FDG-PET in all asymptomatic late-STEMI subjects and providing further evidence in favor of a revascularization of occluded IRA in those with documented myocardial viability.

Takotsubo syndrome (TS) is an acute and reversible form of myocardial stunning preceded by emotional or physical stress, not explained by an obstruction of an epicardial coronary artery as in acute coronary syndrome. Over the last decades, TS is receiving growing attention, leading to an increase in awareness and diagnostic rate. Chest pain and dyspnea are the most common presenting symptoms; however, nonspecific presentations make the diagnosis challenging for clinicians. Here, we present the case of a 76-year-old female who experienced two completely asymptomatic episodes of TS 20 years apart.

Transcatheter left atrial appendage occlusion (LAAO) has emerged as an effective procedure for the prevention of thromboembolic events in non-valvular atrial fibrillation (AF) patients with contraindications to oral anticoagulation. After the procedure, different antithrombotic regimens have been used, in order to prevent device-related thrombus and trying to minimize bleedings. The search for the optimal antithrombotic strategy is still ongoing. We sought to assess efficacy and safety of different antiplatelet therapy (APT) regimens.We enrolled non-randomized consecutive patients who underwent LAAO at the University Hospital of Parma between 2010 and 2021. Three study groups were identified according to post-procedural APT: long (1, ≤12 months)-dual APT (DAPT), short (≤ 1 month)-DAPT, lifelong single APT (SAPT). The choice of the APT was left to multidisciplinary team evaluation. The incidence of the primary outcome, a composite of any ischemic or hemorrhagic event, was assessed at follow-up.We enrolled a total of 130 patients. Technical success was achieved in 123 (94.6%) patients. After LAAO, 39 [31.7%] patients were discharged on short-DAPT, 35 [28.5%] on long-DAPT and 49 [39.8%] on SAPT. After a median follow-up of 32 months, short-DAPT group had a significantly lower occurrence of the primary outcome (3 [7.7%] vs. 7 [20.0%] in long-DAPT vs. 14 [28.6%] in SAPT, p = 0.049], mainly driven by a lower occurrence of the bleeding endpoint (0 vs. 4 [11.4%] in long-DAPT vs. 9 [18.4%] in SAPT, p = 0.020). Finally, comparison of the Kaplan-Meier curves showed that short-DAPT group had a higher primary endpoint-free survival [p = 0.015] compared to the other groups.Post-procedural short-DAPT strategy was associated with better outcomes, mainly driven by reduction of major bleedings.

Atherosclerotic cardiovascular disease is the leading cause of morbidity and mortality worldwide. Several cardiovascular risk factors are implicated in atherosclerotic plaque promotion and progression and are responsible for the clinical manifestations of coronary artery disease (CAD), ranging from chronic to acute coronary syndromes and sudden coronary death. The advent of intravascular imaging (IVI), including intravascular ultrasound, optical coherence tomography and near-infrared diffuse reflectance spectroscopy has significantly improved the comprehension of CAD pathophysiology and has strengthened the prognostic relevance of coronary plaque morphology assessment. Indeed, several atherosclerotic plaque phenotype and mechanisms of plaque destabilization have been recognized with different natural history and prognosis. Finally, IVI demonstrated benefits of secondary prevention therapies, such as lipid-lowering and anti-inflammatory agents. The purpose of this review is to shed light on the principles and properties of available IVI modalities along with their prognostic significance.

Aims Oral anticoagulation (OAC) is the cornerstone therapy for stroke prevention in patients with atrial fibrillation (AF). However, a not negligible proportion of AF patients experiences major bleeding events or is affected by concomitant disorders that represent a contraindication for OAC. Left atrial appendage occlusion (LAAO) has emerged as an effective strategy to minimize the risk of thromboembolism in AF patients (without moderate/severe mitral stenosis or mechanical prosthetic heart valves) that are poor candidates for OAC. After the procedure variable regimens of antithrombotic therapy are prescribed, in order to provide protection and prevent device-related thrombus (DRT). The optimal post-procedural antithrombotic strategy remains to be assessed. Therefore, we aim to evaluate the safety and efficacy of LAAO procedure and the relationship between antiplatelet therapy and outcomes at long-term follow-up. Methods and results We conducted a retrospective observational study including consecutive AF patients who underwent LAAO at Azienda Ospedaliero-Universitaria of Parma from October 2010 to June 2021. The incidence of major ischaemic events [DRT, ischaemic stroke, transient ischaemic attack (TIA) and systemic embolism], Bleeding Academic Research Consortium major bleeding events and net adverse clinical events (major ischaemic + bleeding events) were assessed at follow-up. We enrolled 130 patients [median age 77 years (73; 81)] characterized by both high ischaemic (mean CHA2DS2-VASc 4.48) and bleeding risk (mean HAS-BLED 3.24). Technical procedure success was achieved in 123 (94.6%). Thirty-nine (31.7%) patients were discharged on short (≤1 month)-dual antiplatelet therapy (DAPT); 35 (28.5%) on long-DAPT (1–12 months) and 49 (39.8%) on single antiplatelet therapy (SAPT). Antiplatelet therapy was chosen after multidisciplinary discussion on the basis on the hemorrhagic risk [mean HAS-BLED 3.55; 3.11; 2.97 (P = 0.038) in SAPT, short-DAPT and long-DAPT groups respectively], while no differences were observed in ischaemic risk between the three groups. Clinical follow-up was completed in 119 (98.2%) of successfully implanted patients. After a median follow-up of 31 ± 16 months, 24 (20.2%) patients had a major adverse event: 11 (9.2%) ischaemic events [8 (6.7%) strokes and 3 (2.5%) TIA] and 13 (10.9%) major bleedings. Patients on short-DAPT had a significantly lower occurrence of major bleedings [0 vs. 4 (11.4%) on long-DAPT vs. 9 (18.4%) on SAPT; P = 0.033] and net adverse clinical events [3 (7.7%) vs. 7 (20.0%) on long-DAPT vs. 14 (28.6%) on SAPT; P = 0.005] compared to the other two groups, while no difference was observed in the incidence of major ischaemic events [3 (7.7%) on short-DAPT vs. 3 (8.6%) on long-DAPT vs. 5 (10.2%) on SAPT; P = 0.340]. Conclusions In our cohort of AF patients with a contraindication for OAC therapy, LAAO showed high procedural success; however, long-term major ischaemic and bleeding events were not negligible. Short-DAPT therapy turned out to be the best antiplatelet regimen regarding net ischaemic-hemorrhagic balance. Evidence from well-designed randomized trials would be desirable to guide a tailored approach in the selection of post-procedural antithrombotic regimens.

Over the last decades, inflammation proved to play a pivotal role in atherosclerotic plaque formation, progression and destabilization. Several studies showed that the patients presenting with acute coronary syndrome are at increased risk of adverse cardiovascular events at both short- and long-term follow-up. Results from different clinical trials highlighted that a residual inflammatory risk exist and targeting inflammation is a successful strategy in selected cases associated to an increased inflammatory burden. Recently, the optimization of intracoronary and multimodality imaging allowed to also assess the entity of local inflammation, thus encouraging the individuation of plaque characteristics that portend a higher risk of future cardiovascular events. In this short review, we aim to highlight the role of systemic and local inflammation in acute coronary syndromes, to provide a summarized overview of the possible medical strategies applicable in selected cases and to underline the diagnostic and prognostic potential of multimodality imaging.

Takotsubo syndrome (TS) is a condition of transient regional ventricular systolic dysfunction, usually presenting with acute chest pain and/or dyspnea, that is increasingly recognized especially in post-menopausal women following a psychological or physical stress. Initially considered as a benign condition with an isolated and self-limiting episode, it is now recognized that it is associated with a significant risk of in-hospital mortality and of recurrence. We herein describe a case of a 61-year-old female with left ventricular non-compaction cardiomyopathy (LVNC) who experienced a recurrence of TS, highlighting the potential pathophysiological role for LVNC in predisposing this syndrome and its recurrence. Moreover, we underscored possible therapeutic implications deriving from this case.

AIMS Killip classification is a simple and fast clinical tool for risk stratification of patients presenting with acute coronary syndrome (ACS). However, the clinical features and predictors of high Killip class at admission, and its prognostic impact in patients presenting with anterior ST elevation MI (STEMI) as first clinical cardiovascular event are still poorly known. The aim of this study was to identify the predictors of high Killip class and its impact on in-hospital and follow-up outcomes. METHODS We prospectively enrolled patients with unheralded anterior STEMI because of proximal or mid left anterior descending (LAD) artery categorized according to Killip classification. Patients' characteristics, in-hospital complications and major adverse cardiovascular events (MACEs; composite of all-cause death, heart failure hospitalization and new-onset ACS) at follow-up were collected. RESULTS We enrolled 147 patients [age 66.16±13.33, 113 male patients (76.9%)]. Killip class III--IV occurred in 22 (15%) patients. The median duration of follow-up was 12 [6--15.1] months. At multivariate analysis age [hazard ratio 1.137, 95% CI (1.068--1.209), P < 0.001], prehospital cardiac arrest [hazard ratio 12.145, 95% CI (1.710--86.254), P = 0.013] and proximal LAD lesion [hazard ratio 5.066, 95% CI (1.400--18.334), P = 0.013] were predictive of Killip class III--IV at admission. At multivariate analysis, Killip class III--IV was an independent predictor of in-hospital mortality [hazard ratio 7.790, 95% CI (1.024--59.276], P = 0.047 and of MACEs [hazard ratio 4.155 (1.558--11.082), P = 0.004) at follow-up. CONCLUSION Killip classification performed at the time of admission is a simple and useful clinical marker of a high risk of early and late adverse cardiovascular events.

BackgroundMyocardial bridging (MB) may represent a cause of myocardial ischemia in patients with non‐obstructive coronary artery disease (NOCAD). Herein, we assessed the interplay between MB and coronary vasomotor disorders, also evaluating their prognostic relevance in patients with myocardial infarction and non‐obstructive coronary arteries (MINOCA) or stable NOCAD.Methods and ResultsWe prospectively enrolled patients with NOCAD undergoing intracoronary acetylcholine provocative test. The incidence of major adverse cardiac events, defined as the composite of cardiac death, non‐fatal myocardial infarction, and rehospitalization for unstable angina, was assessed at follow‐up. We also assessed angina status using Seattle Angina Questionnaires summary score. We enrolled 310 patients (mean age, 60.6±11.9; 136 [43.9%] men; 169 [54.5%] stable NOCAD and 141 [45.5%] MINOCA). MB was found in 53 (17.1%) patients. MB and a positive acetylcholine test coexisted more frequently in patients with MINOCA versus stable NOCAD. MB was an independent predictor of positive acetylcholine test and MINOCA. At follow‐up (median, 22 months; interquartile range, 13–32), patients with MB had a higher rate of major adverse cardiac events, mainly driven by a higher rate of hospitalization attributable to angina, and a lower Seattle Angina Questionnaires summary score (allPConclusionsAmong patients with NOCAD, coronary spasm associated with MB may predict a worse clinical presentation with MINOCA and a higher rate of hospitalization attributable to angina at long‐term follow‐up with a low rate of hard events.

Background Coronary microvascular obstruction (MVO) is a noxious condition frequently occurring in patients with ST-elevation myocardial infarction (STEMI) after percutaneous coronary intervention (PCI). However, multiple mechanisms are involved in the pathogenesis of MVO and not yet fully understood. Recent studies suggested that perilipin 2 (PLIN2) may play an important role in lipid metabolism of macrophages resident in atherosclerotic plaques along with a role in enhancing oxidative stress. Purpose To study the association between PLIN2 and MVO in STEMI patients undergoing primary PCI. We also assessed the role of PLIN2 to predict future major cardiovascular events (MACEs). Methods STEMI patients undergoing primary PCI were enrolled. PLIN2 was dosed within 24 hours from admission in peripheral blood monocytes. MVO was assessed using TIMI flow grade and myocardial blush grade on coronary angiogram after PCI, and patients were stratified accordingly (MVO or noMVO). Major adverse cardiac events (defined as a composite of cardiac death, non-fatal myocardial infarction, re-admission for heart failure and target vessel revascularization) were assessed at clinical follow-up. Results Among 100 STEMI patients (mean age, 65.2±12.0 years, 81 males), 33 (33.0%) had MVO. Patients with MVO were older, had higher troponin I peak, C-reactive protein and lower left ventricular ejection fraction on admission. Patients with MVO had significantly higher levels of PLIN2 (1.03±0.28 vs. 0.90±0.16, p=0.019) compared to noMVO patients. Age [OR (95% CI) per year, 1.045 (1.005–1.087), p=0.026] and PLIN2 [OR (95% CI) per unit, 16.606 (2.027–136.030), p=0.009] were associated with MVO at univariate logistic regression analysis. However, only PLIN2 levels [OR (95% CI) per unit, 12.325 (1.446–105.039), p=0.033] were independently associated with MVO at multivariate analysis. Follow up data were available for 76 patients (76%). After a mean follow up of 182.2±126.6 days, 13 MACEs occurred. Patients with MVO had more MACEs [9 (37.5%) vs. 4 (7.7%), p Conclusions In STEMI patients undergoing primary PCI, PLIN2 was independently associated with MVO. PLIN2 was an independent predictor of MACEs at clinical follow-up. These findings suggest that PLIN2 may represent a promising therapeutic target, opening the avenue towards novel therapeutic approaches for MVO. Funding Acknowledgement Type of funding source: None

Over the past few months, health systems worldwide have been put to the test with the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Even though the leading clinical manifestations of the SARS-CoV-2 infection involve the respiratory tract, there is a non-negligible risk of systemic involvement leading to the onset of multi-organ failure with fatal consequences. Since the onset of COVID-19, patients with underlying cardiovascular disease have been at increased risk of poor clinical outcomes with higher death rates. Moreover, the occurrence of new-onset cardiac complications is not uncommon among patients hospitalised for COVID-19. Of importance, a significant portion of COVID-19 patients present with myocardial injury. Herein, the authors discuss the mechanisms leading to myocardial and microvascular injury in SARS-CoV-2 infection and their clinical implications.

Aims Functional alterations of epicardial coronary arteries or coronary microcirculation represent a frequent cause of myocardial infarction and non-obstructive coronary arteries (MINOCA). We aimed at assessing the prognostic value of intracoronary provocative tests in patients presenting with MINOCA and in which other causes of MINOCA have been excluded. Methods and results We prospectively evaluated patients with a diagnosis of MINOCA, excluding patients with aetiologies other than suspected coronary vasomotor abnormalities. Immediately after coronary angiography, an invasive provocative test using acetylcholine or ergonovine was performed. The incidence of death from any cause, cardiac death, and recurrence of acute coronary syndrome (ACS) was assessed at follow-up. We also assessed angina status using Seattle Angina Questionnaires (SAQ). We enrolled 80 consecutive patients [mean age 63.0 ± 10.7 years, 40 (50%) male]. Provocative test was positive in 37 (46.2%) patients without any complication. Among patients with a positive test, epicardial spasm was detected in 24 (64.9%) patients and microvascular spasm in 13 (35.1%) patients. After a median follow-up of 36.0 (range 12.0-60.0) months, patients with a positive test had a significantly higher occurrence of death from any cause [12 (32.4%) vs. 2 (4.7%); P = 0.002], cardiac death [7 (18.9%) vs. 0 (0.0%); P = 0.005], and readmission for ACS [10 (27.0%) vs. 3 (7.0%); P = 0.015] as well as a worse angina status as assessed by SAQ [Seattle score: 88.0 (33.0-100.0) vs. 100.0 (44.0-100.0); P = 0.001] when compared with patients with a negative test. Conclusions We demonstrate that in patients presenting with MINOCA and suspected coronary vasomotor abnormalities, a positive provocative test for spasm is safe and identifies a high-risk subset of patients.