Diagnosis and management of out-of-hospital cardiac arrest secondary to coronary artery spasm

Pharmacological coronary spasm provocative testing in clinical practice: A French Coronary Atheroma and Interventional Cardiology Group (GACI) position paper

Vasospastic angina, also described as Prinzmetal angina, was first described as a variant form of angina at rest with transient ST-segment elevation; it is common and present in many clinical scenarios, including chronic and acute coronary syndromes, sudden cardiac death, arrhythmia and syncope. However, vasospastic angina remains underdiagnosed, and provocative tests are rarely performed. The gold-standard diagnostic approach uses invasive coronary angiography to induce coronary spasm using ergonovine, methylergonovine or acetylcholine as provocative stimuli. The lack of uniform protocol decreases the use and performance of these tests, accounting for vasospastic angina underestimation. This position paper from the French Coronary Atheroma and Interventional Cardiology Group (GACI) aims to review the indications for provocative tests, the testing conditions, drug protocols and positivity criteria.

Abnormal epicardial coronary vasomotor reactivity is associated with altered outcomes

BACKGROUND

The prevalence and significance of abnormal epicardial coronary vasomotor reactivity (ACVR) in patients with symptoms compatible with myocardial ischaemia remains ill-defined. Our diagnostic strategy is to perform a provocative test (PT) in every patient presenting with chest pain at rest, for whom coronary angiography does not reveal significant epicardial coronary artery disease (≥70% stenosis by visual assessment).

AIM

To evaluate such a strategy in terms of incidence of ACVR, PT safety and patient outcomes.

METHODS

The present study was a retrospective observational study with a median clinical follow-up of 5years. The primary outcome was incidence of ACVR in patients with PT. Risk factors for ACVR and clinical follow-up were obtained, and the rate of major adverse cardiovascular and cerebrovascular events (MACCE; death, cardiovascular mortality, myocardial infarction, stroke and coronary revascularization) was reported.

RESULTS

ACVR was documented in 294 (12.4%) of the 2379 patients with PT, out of the 13,654 patients undergoing angiography. Patients with ACVR were more often female (43.9% vs. 30.0%; P<0.0001), current smokers (37.4% vs. 8.7%; P<0.0001) and had a suspected acute coronary syndrome (36.7% vs. 29.1%; P=0.005) at admittance compared with patients without ACVR. During clinical follow-up, MACCE occurred more frequently in patients with (9.8%) than in those without (3.7%) ACVR (hazard ratio [HR] 4.15, 95% confidence interval [CI] 2.62-6.57; P<0.0001), including more myocardial infarctions (4.0% vs. 0.4%; HR 17.8, 95% CI 6.41-49.5; P<0.0001) and more myocardial revascularizations (6.1% vs. 1.1%; HR 9.36, 95% CI 4.67-18.74; P<0.0001) compared with patients with normal PT at baseline.

CONCLUSIONS

ACVR is frequent in patients with symptoms compatible with myocardial ischaemia at rest, with no significant coronary stenosis. PT is a safe strategy to identify a population at high risk of recurrent ischaemic events.

Management of ischaemia with non-obstructive coronary arteries (INOCA)

Up to half of patients undergoing elective coronary angiography for the investigation of chest pain do not present with evidence of obstructive coronary artery disease. These patients are often discharged with a diagnosis of non-cardiac chest pain, yet many could have an ischaemic basis for their symptoms. This type of ischaemic chest pain in the absence of obstructive coronary artery disease is referred to as INOCA (ischaemia with non-obstructive coronary arteries). This comprehensive review of INOCA management looks at why these patients require treatment, who requires treatment based on diagnostic evaluation, what clinical treatment targets should be considered, how to treat patients using a personalised medicine approach, when to initiate treatment, and where future research is progressing.

Current Evidence on Long-Term Prognostic Factors in Vasospastic Angina

Vasospastic angina (VSA) is characterized by a reversible spasm of the coronary arteries and is more prevalent in Asians. Vasodilators, such as calcium channel blockers, are effective in relieving coronary spasms and preventing clinical events. Therefore, the prognosis of VSA is generally known to be better than for significant organic stenosis caused by atherosclerosis. However, coronary vasospasm is sometimes associated with fatal complications such as sudden death, ventricular arrhythmia, and myocardial infarction. Thus, it is very important to identify and actively treat high-risk patients to prevent VSA complications. Here, we will review clinical factors associated with long-term prognosis in patients with VSA.

Myocardial infarction or acute coronary syndrome with non-obstructive coronary arteries and sudden cardiac death: a missing connection

Myocardial infarction with non-obstructive coronary arteries or any acute coronary syndrome (ACS) with normal or near-normal (non-obstructive) coronary arteries (ACS-NNOCA) is an heterogeneous clinical entity, which includes different pathophysiology mechanisms and is challenging to treat. Sudden cardiac death (SCD) is a catastrophic manifestation of ACS that is crucial to prevent and treat urgently. The concurrence of the two conditions has not been adequately studied. This narrative review focuses on the existing literature concerning ACS-NNOCA pathophysiology, with an emphasis on SCD, together with risk and outcome data from clinical trials. There have been no large-scale studies to investigate the incidence of SCD within ACS-NNOCA patients, both early and late in the disease. Some pathophysiology mechanisms that are known to mediate ACS-NNOCA, such as atheromatous plaque erosion, anomalous coronary arteries, and spontaneous coronary artery dissection are documented causes of SCD. Myocardial ischaemia, inflammation, and fibrosis are probably at the core of the SCD risk in these patients. Effective treatments to reduce the relevant risk are still under research. ACS-NNOCA is generally considered as an ACS with more 'benign' outcome compared to ACS with obstructive coronary artery disease, but its relationship with SCD remains obscure, especially until its incidence and effective treatment are evaluated.

Characteristics and Prognosis of Patients with Vasospastic Angina Diagnosed by a Provocation Test with Secondary Prevention Implantable Cardioverter Defibrillator

This study aimed to evaluate the characteristics and prognosis of patients with vasospastic angina (VSA) diagnosed by a provocation test with a secondary prevention implantable cardioverter defibrillator (ICD), compared with patients with organic coronary stenosis. We retrospectively evaluated 309 consecutive patients who received an ICD implantation between January 2010 and March 2018 in our institutions. Of these patients, 206 were implanted with an ICD for secondary prevention. In these 206 patients, 40 with VSA and 72 with organic coronary stenosis were evaluated. Patients with VSA were characterized by younger age (56.1 ± 13.1 versus 69.2 ± 9.5 years, respectively), and a lower prevalence of diabetes (15.0% versus 40.3%, respectively) and heart failure (2.5% versus 26.4%, respectively) than patients with organic coronary stenosis (P < 0.001). Using the Kaplan-Meier analysis, with the VSA group as the reference, the incidence of appropriate ICD shock was similar between the two groups (hazard ratio, 0.85; 95% confidence interval, 0.341-2.109; P = 0.722). The incidence of ventricular fibrillation was significantly higher in the VSA group (hazard ratio, 0.22; 95% confidence interval, 0.057-0.814; P = 0.024), whereas the incidence of major adverse cardiac events, including cardiac death, nonfatal myocardial infarction, hospitalization for unstable angina pectoris, and heart failure, was significantly higher in the organic coronary stenosis group (hazard ratio, 13.1; 95% confidence interval, 1.756-98.17; P = 0.012). In conclusion, patients with VSA with an ICD implanted for secondary prevention have a higher risk of ventricular fibrillation and lower risk of major adverse cardiac events than patients with organic coronary stenosis.

Vasospastic angina and overlapping cardiac disorders in patients resuscitated from cardiac arrest

BACKGROUND

Vasospastic angina (VSA) reportedly accounts for one form of sudden cardiac arrest (SCA). Intracoronary acetylcholine (ACh) testing is useful for diagnosing VSA although invasive provocation testing after SCA is a clinical challenge. In addition, even if the ACh test is positive, any causal relationship between VSA and SCA is often unclear because patients with VSA may have other underlying cardiac disorders.

METHODS

A total of 20 patients without overt structural heart disease who had been fully resuscitated from SCA were included. All patients underwent the ACh provocation test and scrutiny such as cardiac computed tomography or magnetic resonance imaging. Patients were followed up for all-cause death or recurrent SCA including appropriate implantable cardioverter defibrillator therapy.

RESULTS

An ACh provocation test was performed 20 ± 17 days after cardiac arrest. Fifteen out of 20 (75.0%) patients had a positive ACh test and 2 (10.0%) had adverse events such as ventricular tachycardia and transient cardiogenic shock during the test. In patients with a positive ACh test, 6 of 15 (40.0%) patients had other overlapping cardiac disorders such as long QT syndrome, Brugada syndrome, cardiac sarcoidosis, myocarditis, or cardiomyopathy. Long-term prognosis was not different regardless of a positive ACh test or the presence of other cardiac disorders overlapping with VSA.

CONCLUSIONS

Three-quarters of the patients who had been resuscitated from SCA had a positive ACh test. Further examinations revealed other overlapping cardiac disorders in addition to VSA in 40% of patients with a positive ACh test.

Out-of-Hospital Cardiac Arrest due to Coronary Spasm with Recurrent Ventricular Fibrillation

We present a case of ventricular fibrillation (VF) secondary to ischaemia induced by coronary artery spasm. An 82-year-old man initially presented with an out-of-hospital VF arrest. On return of spontaneous circulation (ROSC), he was found to be in fast atrial fibrillation (AF); an invasive coronary angiogram revealed unobstructed coronary arteries. During his hospital stay, he developed chest pain, with concomitant ST elevation on ECG (electrocardiogram), which spontaneously resolved. A repeat coronary angiography revealed coronary spasm. Later, he had further ST elevation resulting in ventricular fibrillation. It became clear his initial presentation was most likely due to coronary vasospasm rather than a plaque-rupture or ventricular scar-related event, and he was thus successfully treated with multiple vasodilators and an implantable cardiac defibrillator. This case report highlights how conventional imaging modalities may not always lead to a diagnosis.

Vasospasm-related Sudden Cardiac Death Has Outcomes Comparable with Coronary Stenosis in Out-of-Hospital Cardiac Arrest

BACKGROUND

Characteristics of coronary vasospasm-related sudden cardiac death are not well understood. We aimed to compare the characteristics and clinical outcomes between coronary vasospasm and stenosis, in out-of-hospital cardiac arrest (OHCA) survivors, who underwent coronary angiogram (CAG).

METHODS

We conducted a multicenter retrospective observational registry-based study at 8 Korean tertiary care centers. Data of OHCA survivors undergoing CAG between 2010 and 2015 were extracted. Patients were divided into vasospasm and stenosis (stenosis > 50%) groups based on CAG findings. The primary and the secondary outcomes were survival and a good neurologic outcome at 30 days after OHCA. Patients in the vasospasm and stenosis groups were propensity score matched.

RESULTS

Of the 413 included patients, vasospasm and stenosis groups comprised 87 and 326 patients, respectively. There were 279 (66.7%) survivors and 206 (49.3%) patients with good neurologic outcomes. The vasospasm group had better clinical characteristics for outcome (younger age, less diabetes and hypertension, more prehospital restoration of spontaneous circulation, higher Glasgow Coma Scale, less ST segment elevation, and less requirement of circulatory support). The vasospasm group had better survival (75/87 vs. 204/326, P < 0.001) and good neurologic outcomes (62/87 vs. 144/326, P < 0.001). However, vasospasm was not independently associated with survival (odds ratio [OR], 0.980; 95% confidence interval [CI], 0.400-2.406) or neurologic outcomes (OR, 0.870; 95% CI, 0.359-2.108) after adjustment and vasospasm was not associated with survival and neurologic outcome in propensity score-matched cohorts.

CONCLUSION

Our analysis of propensity score-matched cohorts finds that vasospasm OHCA survivors have survival and neurologic outcomes comparable with those of stenotic OHCA survivors.

Safety and usefulness of acetylcholine provocation test in patients with no culprit lesions on emergency coronary angiography

BACKGROUND

Vasospastic angina (VSA), which often causes acute coronary syndrome (ACS), can be diagnosed by intracoronary acetylcholine (ACh) provocation test. However, the safety and usefulness of ACh provocation test in ACS patients on emergency coronary angiography (CAG) compared to non-emergency settings are unclear.

METHODS

A total of 529 patients undergoing ACh provocation test during emergency or non-emergency CAG were included. Patients with resuscitated cardiac arrest were excluded. The primary endpoint was adverse events defined as a composite of death, ventricular fibrillation or sustained ventricular tachycardia, myocardial infarction, cardiogenic shock, cardiac tamponade, and stroke within 24 h after ACh provocation test.

RESULTS

There were no significant differences of the clinical characteristics between the groups of emergency (n = 84) and non-emergency (n = 445) ACh provocation test. The rate of positive ACh provocation test was similar between the 2 groups (50% vs. 49%, p = 0.81). Similarly, the incidence of adverse events in patients with emergency and non-emergency ACh provocation test did not significantly differ (1.2% vs. 1.3%, p = 1.00).

CONCLUSION

ACh provocation test can be safely performed in ACS patients with no obstructive culprit lesions on emergency CAG, and may be useful to diagnose VSA in those patients.

Characteristics and clinical assessment of unexplained sudden cardiac arrest in the real-world setting: focus on idiopathic ventricular fibrillation

Aims

Recent studies have shown that in more than half of apparently unexplained sudden cardiac arrests (SCA), a specific aetiology can be unmasked by a careful evaluation. The characteristics and the extent to which such cases undergo a systematic thorough investigation in real-life practice are unknown.

Methods and results

Data were analysed from an ongoing study, collecting all cases of out-of-hospital cardiac arrest in Paris area. Investigations performed during the index hospitalization or planned after discharge were gathered to evaluate the completeness of assessment of unexplained SCA. Between 2011 and 2016, among the 18 622 out-of-hospital cardiac arrests, 717 survivors (at hospital discharge) fulfilled the definition of cardiac SCA. Of those, 88 (12.3%) remained unexplained after electrocardiogram, echocardiography, and coronary angiography. Cardiac magnetic resonance imaging yielded the diagnosis in 25 (3.5%) cases, other investigations accounted for 14 (2.4%) additional diagnoses, and 49 (6.8%) patients were labelled as idiopathic ventricular fibrillation (IVF) (48.7 ± 15 years, 69.4% male). Among those labelled IVF, only 8 (16.3%) cases benefited from a complete workup (including pharmacological testing). Younger patients [odds ratio (OR) 6.00, 95% confidence interval (CI) 1.80-22.26] and those admitted to university centres (OR 3.60, 95% CI 1.12-12.45) were more thoroughly investigated. Genetic testing and family screening were initiated in only 9 (18.4%) and 12 (24.5%) cases, respectively.

Conclusion

Our findings suggest that complete investigations are carried out in a very low proportion of unexplained SCA. Standardized, systematic approaches need to be implemented to ensure that opportunities for specific therapies and preventive strategies (including relatives) are not missed.

Variant Angina and Aborted Sudden Cardiac Death

PURPOSE OF REVIEW

Variant angina, which is characterized by recurrent chest pain and transient ECG changes along with angiographic evidence of coronary artery spasm, generally has a favorable prognosis. However, episodes of ischemia caused by vasospasm may lead to potentially life-threatening ventricular arrhythmias and cardiac arrest, even in patients with no history of prior cardiac disease. This review describes the epidemiology, pathogenesis, clinical spectrum, and management of variant angina, as well as outcomes in patients who present with aborted sudden cardiac death (ASCD).

RECENT FINDINGS

Contrary to prior opinions, evidence from recent observational studies indicate that patients with variant angina presenting with ASCD face a worse prognosis than those without this type of presentation. Predictors of ASCD include age, hypertension, hyperlipidemia, family history of sudden cardiac death, multi-vessel spasm, and left anterior descending artery spasm. Medical therapy alone with calcium channel blockers and nitrates may not be sufficiently protective in these patients and there is lack of concrete data on the optimal management strategy. Current guidelines recommend implantable cardiac defibrillator (ICD) therapy in patients who are survivors of cardiac arrest caused by ventricular fibrillation or unstable ventricular tachycardia after reversible causes are excluded, and should strongly be considered in these patients. Although medical therapy is absolutely imperative for patients with variant angina and a history of ASCD, ICD therapy in these patients is justified. Further large-scale studies are required to determine whether ICD therapy can improve survival in this high-risk group of patients.

Significance of Coronary Artery Spasm Diagnosis in Patients With Early Repolarization Syndrome

BACKGROUND

Previously described patients with early repolarization syndrome (ERS) may have experienced silent coronary artery spasm (CAS) because the diagnosis of CAS was mainly based on symptoms or coronary angiography findings, without performing a spasm provocation test. This study investigated the significance of CAS diagnosis and evaluated the incidence of silent CAS in patients with possible ERS (ie, idiopathic ventricular fibrillation [VF] and inferolateral J wave).

METHODS AND RESULTS

The study included 34 patients with idiopathic VF and inferolateral J wave. Thirteen patients (38%) were diagnosed as having CAS on the basis of coronary angiography with spasm provocation test (n=8) and documentation of spontaneous ST elevation (n=5). Of the 13 patients with CAS, 5 (38%) did not experience chest symptoms before and during VF, and were diagnosed as having silent CAS. The remaining 21 patients (62%), with a negative provocation test result and absence of chest symptoms, were considered to have ERS. During the 92 months of follow-up, patients with CAS receiving appropriate medical treatment with antianginal drugs showed a favorable outcome. In contrast, 4 of 21 patients with ERS (19%) had VF recurrences. The use of monotherapy or combination therapy, consisting of quinidine, cilostazol, and bepridil, in the 4 patients with ERS, was effective in suppressing VF.

CONCLUSIONS

Approximately 40% of patients with CAS with documented VF and inferolateral J wave did not experience chest symptoms at the first VF, and could have been misdiagnosed as having ERS. The use of the spasm provocation test is considered essential to differentiate patients for optimal medical treatment.

Clinical value of ST-segment change after return of spontaneous cardiac arrest and emergent coronary angiography in patients with out-of-hospital cardiac arrest: Diagnostic and therapeutic importance of vasospastic angina

Background:

We investigated the association between initial ST-segment change after return of spontaneous circulation (ROSC) and the incidence of acute coronary lesions in patients with out-of-hospital cardiac arrest (OHCA), and clinical outcomes of patients with OHCA caused by vasospastic angina pectoris (VSA).

Methods:

Among 2779 OHCA patients in our institution, all patients with ROSC underwent emergent coronary angiography (CAG) except for those with an obvious extra-cardiac cause of OHCA. Initial ST-segment changes after ROSC were reviewed, and 30-day survival and neurological outcome (Cerebral Performance Category) were evaluated.

Results:

Of the 155 patients, 52 (34%) had ST-segment elevation (STE) and 103 (66%) had non-STE. Significant coronary culprit lesions were present in 81% of patients with STE and in 33% of patients with non-STE ( P<.001). Percutaneous coronary intervention (PCI) was successful in 60 patients (93.8%) and failed in 4 patients (6.2%). Among 155 patients, 74 patients (47.7%) had favorable neurological prognosis, and 104 patients (67.1%) were alive at 30 days. ST-segment analysis showed good positive predictive value (81%) but low negative predictive value (68%) in diagnosing the presence of acute coronary lesions. VSA was found in 5 patients (9.6%) in the STE group and in 12 patients (11.7%) in the non-STE group. Of these 17 patients, 9 (52.9%) had favorable neurological outcome and 14 (82.4%) were alive at 30 days.

Conclusion:

An acute culprit lesion may be the cause of OHCA even in the absence of STE. In survivors of OHCA with normal coronary arteries, spasm provocation testing should be performed to detect VSA as a cause of the arrest.

Prognosis of Variant Angina Manifesting as Aborted Sudden Cardiac Death

BACKGROUND

The long-term prognosis of patients with variant angina presenting with aborted sudden cardiac death (ASCD) is unknown.

OBJECTIVES

The purpose of this study was to evaluate the long-term mortality and ventricular tachyarrhythmic events of variant angina with and without ASCD.

METHODS

Between March 1996 and September 2014, 188 patients with variant angina with ASCD and 1,844 patients with variant angina without ASCD were retrospectively enrolled from 13 heart centers in South Korea. The primary endpoint was cardiac death.

RESULTS

Predictors of ASCD manifestation included age (odd ratio [OR]: 0.980 by 1 year increase; 95% confidence interval [CI]: 0.96 to 1.00; p = 0.013), hypertension (OR: 0.51; 95% CI: 0.37 to 0.70; p < 0.001), hyperlipidemia (OR: 0.38; 95% CI: 0.25 to 0.58; p < 0.001), family history of sudden cardiac death (OR: 3.67; 95% CI: 1.27 to 10.6; p = 0.016), multivessel spasm (OR: 2.06; 95% CI: 1.33 to 3.19; p = 0.001), and left anterior descending artery spasm (OR: 1.40; 95% CI: 1.02 to 1.92; p = 0.04). Over a median follow-up of 7.5 years, the incidence of cardiac death was significantly higher in ASCD patients (24.1 per 1,000 patient-years vs. 2.7 per 1,000 patient-years; adjusted hazard ratio [HR]: 7.26; 95% CI: 4.21 to 12.5; p < 0.001). Death from any cause also occurred more frequently in ASCD patients (27.5 per 1,000 patient-years vs. 9.6 per 1,000 patient-years; adjusted HR: 3.00; 95% CI: 1.92 to 4.67; p < 0.001). The incidence rate of recurrent ventricular tachyarrhythmia in ASCD patients was 32.4 per 1,000 patient-years, and the composite of cardiac death and ventricular tachyarrhythmia was 44.9 per 1,000 patient-years. A total of 24 ASCD patients received implantable cardioverter-defibrillators (ICDs). There was a nonsignificant trend of a lower rate of cardiac death in patients with ICDs than those without ICDs (p = 0.15).

CONCLUSIONS

The prognosis of patients with variant angina with ASCD was worse than other patients with variant angina. In addition, our findings supported ICDs in these high-risk patients as a secondary prevention because current multiple vasodilator therapy appeared to be less optimal.

Usefulness of Testing for Coronary Artery Spasm and Programmed Ventricular Stimulation in Survivors of Out-of-Hospital Cardiac Arrest

Background—

Optimal therapy for patients resuscitated from out-of-hospital cardiac arrest (OHCA) who are not found to have structural heart disease remains to be established, especially regarding the use of implantable cardioverter-defibrillators. Coronary artery spasm (CAS) and lethal ventricular arrhythmias are important causes of OHCA.

Methods and Results—

In 47 consecutive OHCA survivors without structural heart disease who had fully recovered (M/F 44/3, 43±13 years.), we performed dual induction tests, including acetylcholine provocation test first followed by programmed ventricular stimulation after 1 to 2 weeks. Patients with CAS were treated with calcium channel blocker–based antianginal medications; implantable cardioverter-defibrillators were implanted in all patients. The results of the dual induction tests defined 4 groups: CAS alone (n=7), inducible ventricular arrhythmias alone (n=13), both positive (n=24), and both negative (n=3). During a median follow-up period of 38 months, ventricular fibrillation recurred in all groups except the both-negative group. Of the 16 patients with a type I Brugada ECG, 2 had CAS alone, 8 had ventricular arrhythmias alone, and 6 had both positive. No ventricular fibrillation episodes were observed in the CAS-alone patients who did not also have Brugada syndrome. Kaplan–Meier analysis showed that the CAS-alone group was at lower risk for OHCA recurrence as compared with the Brugada syndrome group (log-rank test; P =0.036).

Conclusions—

Among OHCA survivors without structural heart disease, provokable CAS and ventricular arrhythmias are common and can be seen in Brugada syndrome. CAS alone without Brugada syndrome who are treated for CAS may be a lower-risk group.

Long-term Prognosis of Patients With Non-ST-segment Elevation Acute Myocardial Infarction and Coronary Arteries Without Significant Stenosis

INTRODUCTION AND OBJECTIVES

There is debate regarding the prognostic significance of the absence of significant coronary lesions in patients with non-ST-segment elevation acute myocardial infarction. We investigated long-term prognosis in a contemporary cohort of these patients.

METHODS

Retrospective observational study of 5203 patients with acute coronary syndrome. Propensity score matching was used to create 2 groups of 367 patients with non-ST-segment elevation acute myocardial infarction matched by the absence or presence of significant coronary lesions. In the matched cohort, we determined the impact of the absence of significant coronary lesions on mortality or readmission for acute coronary syndrome for 4.8 (2.6) years after discharge.

RESULTS

Mortality or readmission for acute coronary syndrome was lower among patients without significant lesions (26.4% vs 32.7%; P = .09). Mortality in both groups was 19.1%. In contrast, patients without significant lesions had a lower incidence of readmission for acute coronary syndrome (2.0/100 vs 3.9/100 person-years; P = .003). The incidence of mortality or readmission for acute coronary syndrome was similar in patients without significant lesions and those with significant 1-vessel disease (26.4% vs 27.5%; P = .19), but lower than that in patients with 2-vessel disease (37.8%; P = .007) and 3-vessel disease or left main coronary artery disease (41.1%; P = .002).

CONCLUSIONS

Patients with non-ST-segment elevation acute myocardial infarction and coronary arteries without significant lesions have similar long-term mortality but lower readmission rates for acute coronary syndrome than patients with significant lesions. Mortality or readmission for acute coronary syndrome is similar in patients without significant lesions and patients with 1-vessel disease, but lower than in patients with disease in 2 or more vessels.

Prognosis of patients with non-ST-segment-elevation myocardial infarction and nonobstructive coronary artery disease: propensity-matched analysis from the Acute Catheterization and Urgent Intervention Triage Strategy trial

BACKGROUND

Troponin elevation is a risk factor for mortality in patients with non-ST-segment-elevation acute coronary syndromes. However, the prognosis of patients with troponin elevation and nonobstructive coronary artery disease (CAD) is unknown. Our objective was therefore to evaluate the impact of nonobstructive CAD in patients with non-ST-segment-elevation acute coronary syndromes and troponin elevation enrolled in the Acute Catheterization and Urgent Intervention Triage Strategy (ACUITY) trial.

METHODS AND RESULTS

In the ACUITY trial, 3-vessel quantitative coronary angiography was performed in a formal substudy of 6921 patients presenting with non-ST-segment-elevation acute coronary syndromes. Patients with elevated admission troponin levels were stratified by the presence or absence of obstructive CAD (any lesion with quantitative diameter stenosis >50%). Propensity score matching was performed to adjust for baseline characteristics. Of 2442 patients with elevated troponin, 197 (8.8%) had nonobstructive CAD. Maximum diameter stenosis was 87.4 (73.2, 100.0) versus 22.6 (19.2, 25.7; P<0.0001) in patients with versus without obstructive CAD, respectively. Propensity matching yielded 117 patients with nonobstructive CAD and 331 patients with obstructive CAD, with no significant baseline differences between groups. In the matched cohort, overall 1-year mortality was significantly higher in patients with nonobstructive CAD (5.2% versus 1.6%; hazard ratio [95% confidence interval]=3.44 [1.05, 11.28]; P=0.04), driven by greater noncardiac mortality. Conversely, recurrent myocardial infarction and unplanned revascularization rates were significantly higher in patients with obstructive CAD.

CONCLUSIONS

Patients with non-ST-segment-elevation acute coronary syndromes and elevated troponin levels but without obstructive CAD, while having low rates of subsequent myocardial infarction and unplanned revascularization, are still at considerable risk for 1-year mortality from noncardiac causes.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00093158.

Favorable outcomes of patients with vasospastic angina associated with cardiac arrest

BACKGROUND

The long-term survival of vasospastic angina (VSA) patients is generally good, so long as they remain on calcium channel blockers (CCBs) and avoid smoking. However, the pathogenesis, appropriate treatments, and prognosis of VSA associated with cardiac arrest remain unclear. This study aimed to elucidate the clinical features and long-term outcomes of patients with VSA associated with cardiac arrest.

METHODS AND RESULTS

Eighteen consecutive patients with VSA associated with cardiac arrest [13 patients resuscitated after out-of-hospital cardiac arrest (OHCA) and 5 resuscitated after in-hospital-cardiac arrest] were retrospectively analyzed. Sixteen of the eighteen patients were smokers. None had other cardiac diseases possibly causing cardiac arrest. Although 1 patient resuscitated after OHCA later died of cerebral hypoxia, the remaining 17 were discharged without complications. One patient died of cancer 50 months after resuscitation. The other 16 patients are still alive and none have shown ventricular arrhythmias, syncope, or cardiac arrest during a mean follow-up of 67 months. All are treated with long-acting CCBs/nitrates and successfully quit smoking. Six patients received implantable cardioverter defibrillators (ICD). However, none demonstrated any ventricular arrhythmias and appropriate ICD actuation was achieved.

CONCLUSION

Appropriate medical treatment can achieve favorable long-term outcomes even for patients with VSA associated with cardiac arrest.

Syncope caused by coronary artery spasm without chest pain leading to ventricular fibrillation

We present a case of syncope caused by coronary artery spasm without chest pain leading to ventricular fibrillation despite of vasodilator therapy with a calcium channel blocker (CCB). A 68-year-old man presented with two episodes of syncope without chest pain. Ergonovine provocation test induced a diffuse spasm in the right coronary artery (RCA) and subsequently, ventricular fibrillation. Under the therapy with multiple vasodilators including two CCBs, a second ergonovine provocation induced a spasm of the proximal RCA resulting in complete obstruction. Owing to drug-resistant coronary spasm complicated by ventricular fibrillation, an implantable cardioverter defibrillator (ICD) was implanted. This case report highlights the occurrence of syncope caused by coronary artery spasm without chest pain that was refractory to single CCB therapy and needed ICD implantation. Therapy with multiple vasodilators, including two or more CCBs, along with ICD implantation may be required to treat such refractory coronary artery spasms leading to lethal arrhythmia.

Clinical characteristics and long-term prognosis of vasospastic angina patients who survived out-of-hospital cardiac arrest: multicenter registry study of the Japanese Coronary Spasm Association

BACKGROUND

Coronary artery spasm plays an important role in the pathogenesis of ischemic heart disease; however, its role in sudden cardiac death remains to be fully elucidated. We examined the clinical characteristics and outcomes of patients with vasospastic angina (VSA) in our nationwide multicenter registry by the Japanese Coronary Spasm Association.

METHODS AND RESULTS

Between September 2007 and December 2008, 1429 patients with VSA (male/female, 1090/339; median, 66 years) were identified. They were characterized by a high prevalence of smoking and included 35 patients who survived out-of-hospital cardiac arrest (OHCA). The OHCA survivors, as compared with the remaining 1394 non-OHCA patients, were characterized by younger age (median, 58 versus 66 years; P<0.001) and higher incidence of left anterior descending coronary artery spasm (72% versus 53%, P<0.05). In the OHCA survivors, 14 patients underwent implantable cardioverter-defibrillator (ICD) implantation while intensively treated with calcium channel blockers. Survival rate free from major adverse cardiac events was significantly lower in the OHCA survivors compared with the non-OHCA patients (72% versus 92% at 5 years, P<0.001), including appropriate ICD shocks for ventricular fibrillation in 2 patients. Multivariable analysis revealed that OHCA events were significantly correlated with major adverse cardiac events (hazard ratio, 3.25; 95% confidence interval, 1.39 to 7.61; P<0.01).

CONCLUSIONS

These results from the largest vasospastic angina cohort indicate that vasospasm patients who survived OHCA are high-risk population. Further studies are needed to determine whether implantable cardioverter-defibrillator therapy improves patient prognosis.

[Non invasive methylergometrine test should be carried out after cardiac arrest due to coronary spasm?]

A 59-year-old man was admitted after cardiac arrest with successful reanimation. There was no significant coronary lesion. We conclude to the diagnosis of coronary spasm after the occurrence of a chest pain with anterior ST elevation reversible with intravenous nitrates. One month later, non-invasive methylergometrine test was carried out and complicated by a cardiac arrest due to complete heart block and asystole treated by chest compression, molsidomine and epinephrine. No cardiac event occurred within the following six months. Technique (invasive versus not invasive) and indication of methylergometrine test for the follow-up of severe manifestations of coronary spasm should be better specified in international guidelines.

Spontaneous and simultaneous multivessel coronary spasm causing multisite myocardial infarction, cardiogenic shock, atrioventricular block, and ventricular fibrillation

A 57-year-old Taiwanese man with a past history of variant angina developed simultaneous anterior and inferior myocardial infarction, atrioventricular block, cardiogenic shock, and eventually ventricular fibrillation. Left coronary angiography revealed simultaneous occlusion of the left anterior descending and the left circumflex coronary arteries, which was relieved by intracoronary administration of isosorbide dinitrate. This is the first report of such a case in the English-language medical literature.