Clinical syndrome of variant angina with normal coronary arteriogram

Relationships between sex and in-hospital outcomes of patients with acute cardiogenic shock receiving mechanical circulatory support

BACKGROUND

Cardiovascular disease is the leading cause of mortality in women. Despite this there is a paucity of data on the impact of sex on utilization and outcomes of temporary mechanical circulatory support (tMCS) in patients hospitalized with Acute Myocardial Infarction (AMI) Cardiogenic Shock (CS).

METHODS

We examined the 2016-2019 National Inpatient Sample database to identify cases of AMI-CS. Men were used as our control group, while women comprised our cohort. The primary outcome was in-hospital mortality. Secondary outcomes included the use of tMCS including; left ventricular assist device (LVAD) use, Impella use, and Intra-Aortic Balloon Pump (IABP) use, length of stay (LOS) and total hospitalization cost (THC). Multivariate linear and logistic regression models were used to adjust for confounders.

RESULTS

Among patients hospitalized for AMI (N = 2,622,939), 37.7 % were Female. A Female sex was associated with a higher inpatient mortality (adjusted OR [aOR] 1.06, p < 0.001), a lower likelihood of LVAD use (2.3 % vs. 2.9 % and p < 0.001), IABP use (3.0 % vs. 4.4 % and p < 0.001), Impella use (1.0 % vs. 1.5 % and p < 0.001), a longer mean LOS (4.4 vs 4.3 days and p < 0.001) and lower THC ($88,097 vs. $104,101, p < 0.001) compared to male patients for AMI-CS.

CONCLUSION

Female patients admitted for AMI-CS were less likely to receive tMCS despite a higher mortality rate and a slightly longer LOS compared to male patients. Further studies are necessary to confirm these findings and elucidate clearer causality for such disparities.

Coronary Artery Spasm-Related Heart Failure Syndrome: Literature Review

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

Myocardial Ischemic Syndromes, Heart Failure Syndromes, Electrocardiographic Abnormalities, Arrhythmic Syndromes and Angiographic Diagnosis of Coronary Artery Spasm: Literature Review

In coronary artery spasm (CAS), an excess coronary vasoconstriction causing total or subtotal vessel occlusion could lead to syncope, heart failure syndromes, arrhythmic syndromes, and myocardial ischemic syndromes including asymptomatic myocardial ischemia, stable and unstable angina, acute myocardial infarction, and sudden cardiac death. Although the clinical significance of CAS has been underrated because of the frequent absence of symptoms, affected patients appear to be at higher risk of syncope, serious arrhythmias, and sudden death than those with classic Heberden's angina pectoris. Therefore, a prompt diagnosis has important therapeutic implications, and is needed to avoid CAS-related complications. While a definitive diagnosis is based mainly on coronary angiography and provocative testing, clinical features may help guide decision-making. We perform a literature review to assess the past and current state of knowledge regarding the clinical features, electrocardiographic abnormalities and angiographic diagnosis of CAS, while a discussion of mechanisms is beyond the scope of this review.

Gender differences in the clinical features and outcomes of patients with coronary artery disease

INTRODUCTION

Women have been at a higher risk for adverse cardiac events following percutaneous coronary intervention (PCI), compared with men. Areas covered: In this review, authors discuss the gender differences that can affect the clinical outcomes after PCI and the important points that can be improved on. Expert commentary: Various factors, such as old age and higher prevalence of comorbidities, have been considered to account for the worse clinical outcomes of PCI in women than in men. In addition, men and women have different presentations of angina or acute coronary syndrome (ACS); atypical symptoms are more frequent in women. This variation of the clinical presentation in women likely contributes to the misdiagnosis or delayed recognition of ischemia, which may explain the worse clinical outcomes. In addition, compared with men, women are less likely to be referred for revascularization for coronary artery disease (CAD) and receive less of these guideline-recommended therapies. Recently, sex differences in cardiovascular events have decreased, especially among stable CAD patients, but sex differences in the clinical outcomes of ACS remain. Further evolution of treatment is expected to narrow these sex differences among patients with CAD and improve the clinical outcomes of both men and women.

Acute coronary syndromes in women and men

Evidence of sex-related disparities in the care and outcomes of patients with acute coronary syndrome (ACS) emerged >30 years ago, and yet the mechanisms behind these sex-specific differences remain unclear. In this Review, we discuss the current literature on differences between women and men in the clinical presentation, pathophysiology, evaluation, management, and outcomes of ACS. Although the symptoms of ACS and the benefits of therapy generally overlap between women and men, women continue to receive less-aggressive invasive and pharmacological therapy than men. In addition, young women in particular have worse short-term and long-term outcomes than men. To understand better the mechanisms behind these continued disparities, we have identified areas of future research that need to be urgently addressed in fields that range from clinical evaluation and management, to increasing representation of women in research.

Analytic Review: Treatment of Coronary Artery Spasm and Variant Angina

Coronary artery spasm is an abnormal constriction of the conductive arteries that produces myocardial ischemia in the absence of any marked increase in heart rate or blood pressure. Ischemia is a transient phenomenon and is promptly reversed spontaneously or by nitroglycerine. The so-called "hallmark of spasm"—ST segment elevation—is evidence for severe myocardial ischemia rather than conclusive evidence for coronary artery spasm. Any process that transiently or permanently restricts coronary blood flow (e.g., transient occlusion by thrombus) will produce similar electrocardiogram (EKG) abnormalities.

Most patients with symptoms and EKG changes related to coronary artery spasm respond to sublingual nitrates. Thus, their use for relief of the acute ischemic episode remains the initial treatment of choice. When symptoms are moderate in severity or unacceptably controlled in frequency using nitrates alone, other pharmacologic measures are needed.

When spasm is superimposed upon hemodynamically important atherosclerotic obstruction, the favorable response to calcium antagonist may not be as great as that seen when spasm occurs alone. One possible explanation is that spasm is not really occurring. The ST segment elevation may be related to transient total occlusion from platelet aggregation or thrombosis. Thus, aspirin may be the drug of choice. However, if spasm is the culprit, recommendations for surgery and angioplasty require proof that spasm is occurring in and around the area of fixed atherosclerotic obstruction and not in other vessels or over the entire course of the distal vessel.

Vasotonic Angina as a Cause of Myocardial Ischemia in Women

The frequency, presentation, prognosis, and treatment of myocardial ischemia differ in men and women. A large proportion of women who have "normal" coronary arteries on angiography without any significant evidence of flow-limiting disease also have biochemical or imaging evidence of myocardial ischemia. In these women it is believed to be a dysfunction of coronary microcirculation and/or macrocirculation, or vasotonic angina (VA), that leads to abnormal vasoconstriction, and potentially to myocardial infarction, ventricular arrhythmias, and sudden death. Despite having a "normal" or near normal coronary angiography, these women should therefore undergo additional testing with acetylcholine to assess endothelial function. Long-term survival is believed to be relatively good. Predictors of poorer prognosis include documentation of severe endothelial dysfunction and presence of concurrent angiographycally visible coronary atherosclerosis. Because atherosclerosis is common in patients with VA, medical and lifestyle interventions for preventing or treating atherosclerosis should be implemented when appropriate. Angiotensin converting enzyme inhibitors are the mainstays of medical therapy for VA. Other agents have been tried with variable success, including beta-blockers. There are no available data on any specific treatment of VA in women (versus men).

Acute Myocardial Infarction in Women: A Scientific Statement From the American Heart Association

Cardiovascular disease is the leading cause of mortality in American women. Since 1984, the annual cardiovascular disease mortality rate has remained greater for women than men; however, over the last decade, there have been marked reductions in cardiovascular disease mortality in women. The dramatic decline in mortality rates for women is attributed partly to an increase in awareness, a greater focus on women and cardiovascular disease risk, and the increased application of evidence-based treatments for established coronary heart disease. This is the first scientific statement from the American Heart Association on acute myocardial infarction in women. Sex-specific differences exist in the presentation, pathophysiological mechanisms, and outcomes in patients with acute myocardial infarction. This statement provides a comprehensive review of the current evidence of the clinical presentation, pathophysiology, treatment, and outcomes of women with acute myocardial infarction.

Presentation, management, and outcomes of ischaemic heart disease in women

Scientific interest in ischaemic heart disease (IHD) in women has grown considerably over the past 2 decades. A substantial amount of the literature on this subject is centred on sex differences in clinical aspects of IHD. Many reports have documented sex-related differences in presentation, risk profiles, and outcomes among patients with IHD, particularly acute myocardial infarction. Such differences have often been attributed to inequalities between men and women in the referral and treatment of IHD, but data are insufficient to support this assessment. The determinants of sex differences in presentation are unclear, and few clues are available as to why young, premenopausal women paradoxically have a greater incidence of adverse outcomes after acute myocardial infarction than men, despite having less-severe coronary artery disease. Although differential treatment on the basis of patient sex continues to be described, the extent to which such inequalities persist and whether they reflect true disparity is unclear. Additionally, much uncertainty surrounds possible sex-related differences in response to cardiovascular therapies, partly because of a persistent lack of female-specific data from cardiovascular clinical trials. In this Review, we assess the evidence for sex-related differences in the clinical presentation, treatment, and outcome of IHD, and identify gaps in the literature that need to be addressed in future research efforts.

Progressive deterioration of left ventricular function in a patient with a normal coronary angiogram

Cardiac ischemia with a normal coronary angiogram can be caused by coronary microvascular dysfunction. A favorable prognosis, with excellent long-term clinical outcome, without major acute coronary events, has been consistently reported in these patients. We report a patient with a normal coronary angiogram and 3 episodes of myocardial infarctions, where the formation of a ventricular aneurysm and progressive deterioration of left ventricular function was documented, and hypoperfusion of the myocardium was confirmed by cardiovascular magnetic resonance imaging. This case suggests that myocardial ischemia caused by coronary microvascular dysfunction could have a poor prognosis. Whether this case represents a special clinical condition which is between the cardiac syndrome X and coronary artery disease remains to be investigated.

Role of coronary spasm in different anginal syndromes

Angina pectoris is a clinical syndrome caused by transient myocardial ischaemia due to an imbalance between myocardial oxygen demand and supply. It is now evident that coronary artery spasm plays an important role in the pathogenesis of various forms of angina pectoris. Angina pectoris that is mainly caused by coronary artery spasm (coronary spastic angina) has one or more of the following characteristics: 1) the attack occurs at rest, 2) the attack is associated with ST-segment elevation in the ECG, 3) the attack has a variable exercise threshold, and 4) the attack is suppressed by Ca-antagonists but not by beta-adrenergic blocking agents. On the other hand, angina pectoris that is caused by increased myocardial oxygen demand in the presence of severe and extensive organic stenosis (organic angina) has the following characteristics: 1) the attack is induced by constant amount of exertion irrespective of hour and day and is relieved by rest, 2) the attack is associated with ST-segment depression in the ECG, and 3) the attack is suppressed by beta-adrenergic blocking agents, which decrease myocardial oxygen demand.

Coronary artery spasm--clinical features, diagnosis, pathogenesis, and treatment

Coronary (artery) spasm plays an important role in the pathogenesis of ischemic heart disease, including stable angina, unstable angina, myocardial infarction, and sudden death. The prevalence of coronary spasm differs among populations, is higher in Japan and Korea than in the Western countries probably due to genetic as well as environmental factors. Coronary spasm occurs most often from midnight to early morning and is usually not induced by exercise in the daytime. The attacks of coronary spasm are associated with either ST segment elevation or depression, or negative U wave on ECG. Patients with multi-vessel coronary spasm may suffer from lethal arrhythmia, including advanced AV block, ventricular tachycardia or fibrillation, or even sudden death, and they are often resistant to conventional medical therapy including Ca-channel blockers (CCBs). Endothelial nitric oxide (NO) activity is reduced and markers of oxidative stress are elevated in patients with coronary spasm. Thrombogenesis is enhanced and plasma levels of hsCRP and P-selection are elevated in patients with coronary spasm. Thus, patients with coronary spasm have endothelial dysfunction and are suffering from a low-grade chronic inflammation. Polymorphisms of endothelial NO synthase, smoking, and low-grade inflammation are the most important risk factors for coronary spasm. Coronary spasm is a hyper-contraction of coronary smooth muscle triggered by an increase of intracellular Ca2+ in the presence of an increased Ca2+ sensitivity. It has been shown that RhoA/ROCK pathway is involved in Ca2+ sensitivity and that the reduced endothelial NO activity results in increased Ca2+ sensitivity through enhanced RhoA/ROCK pathway. Accordingly, it is possible that in addition to CCBs, RhoA/ROCK pathway blockers may prove to be useful for the treatment of coronary spasm.

Comparison of clinical and angiographic features and longterm follow-up events between patients with variant angina and patients with ST elevation myocardial infarction

We investigated to what extent patients with variant angina and significant coronary stenosis (>or=70%) present a clinical and angiographic profile similar to patients with ST elevation myocardial infarction. Thus, the clinical and angiographic features as well as follow-up events of 200 patients were prospectively analyzed and were compared with those of 422 patients with a first ST elevation myocardial infarction survivors of the early phase (3 days) and those of 70 patients with variant angina and non significant stenosis. Age and incidence of smoking, systemic hypertension, diabetes and maximum ST elevation were similar in the 2 groups. Furthermore, among patients with significant coronary stenosis, stenosis severity and the proportion of eccentric lesions were also comparable. Incidence of recent-within 30 days prior to admission-angina at rest was higher in variant angina patients with significant stenosis (67% vs. 27%, p<0.001) than in those with myocardial infarction but long standing angina at rest (>30 days) was low and comparable in these 2 groups (15% vs. 11%, ns). Also, in a 5-year follow-up most patients from these 2 groups were free from angina at rest (86% vs. 84%) which in variant angina patients was largely attributable to a high revascularization rate (72%). Moreover, the rate of myocardial infarction/cardiac death (20% vs. 19%) was also similar. Patients with variant angina and non-significant stenosis, however, had longer antecedent angina, more frequent follow-up angina and a lower incidence of cardiac events than the other 2 groups. Thus, these findings suggest that patients with variant angina and significant coronary stenosis generally behave as an acute coronary syndrome-likely associated with an acutely complicated plaque-rather than as recurrent vasospastic angina, and should be managed accordingly.

Endothelial function and coronary spastic angina

Coronary spasm plays an important role in the pathogenesis of not only variant angina but also coronary heart disease in general including acute coronary syndromes, especially in the Japanese population. The vascular endothelium has been reported to be a multifunctional organ whose integrity is essential for normal vascular physiology. Vascular endothelial dysfunction can be a critical factor in the pathogenesis of ischemic heart disease. Acetylcholine and methacholine cause vasodilation by endothelium-derived relaxing factor when the endothelium is functioning normally, whereas they cause vasoconstriction when the endothelium is removed or damaged. Coronary spasm can be induced by a variety of stimuli with different mechanisms of action, including acetylcholine and methacholine. Patients with coronary spasm may have a disturbance in endothelial function as well as local hyperreactivity of the coronary arteries.

Coronary vasospasm and the regulation of coronary blood flow

Under physiologic conditions, epicardial arteries contribute minimally to coronary vascular resistance. However, in the presence of endothelial dysfunction, stimuli that normally produce vasodilation may instead cause constriction. Examples include neural release of acetylcholine or norepinephrine, platelet activation and production of serotonin and thrombin, and release of local factors such as bradykinin. This shift from a primary endothelial-mediated vasodilator influence to one of endothelial dysfunction and unchecked vasoconstriction is precisely the milieu in which coronary vasospasm is observed. This condition, which typically occurs during periods of relatively sedentary activity, is associated with focal and transient obstruction of an epicardial arterial segment resulting in characteristic echocardiographic changes and symptoms of myocardial ischemia. This review highlights the current understanding of mechanisms regulating the coronary circulation during health and examines the pathophysiologic changes that occur with coronary spasm. Genetic and other predisposing conditions are addressed, as well as novel therapies based on recent mechanistic insights of the coronary contractile dysfunction associated with coronary spasm.

Circadian variation of autonomic nervous activity in patients with multivessel coronary spasm

The present study investigated whether the circadian rhythm of sympathovagal activity is related to the severity of coronary spasm or multivessel coronary spasm. Heart rate variability was examined in 22 consecutive patients with vasospastic angina provoked by intracoronary injection of acetylcholine, who had either multivessel spasm (Group M, n=11 ) or single vessel spasm (Group S, n= 11), in 20 subjects without coronary artery disease (Group C) and 20 patients with effort angina who had organic coronary artery stenosis (Group E). The frequency domain indices were analyzed, including low frequency (LF: 0.04-0.15 Hz) and high frequency (HF: 0.15-0.4Hz), the latter being an index of efferent parasympathetic activity, and the ratio (L/H) as an index of sympathovagal balance. The circadian variation of the parameters was analyzed by its pattern and was quantified by the difference of the mean values between daytime and nighttime. Although the HF power increased during nighttime in Groups C and S, this increase was attenuated in Groups E and M. The circadian variation of the L/H ratio (ie, a drop during nighttime) was smaller in the S and M groups than in Groups C and E. Accordingly, in Group M, the circadian variation of both sympathetic and parasympathetic nervous activity was attenuated, but in Group S, the variation of sympathetic nervous activity, but not parasympathetic nervous activity, was decreased. These data suggest that relatively enhanced sympathetic nervous activity at night may be involved in the mechanism underlying multivessel coronary spasm.

Differences between coronary hyperresponsiveness to ergonovine and vasospastic angina

The objective of the present study was to investigate the differences between coronary hyperresponsiveness without ischemia and vasospastic angina in an ergonovine provocation test using multivariate analysis. We have sometimes experienced a more than 50% narrowing response of vascular diameter without ischemia in a coronary response to ergonovine. We studied 107 patients with less than 50% stenosis in a coronary arteriogram. Their vascular responses to ergonovine were measured and the patients were divided into three groups, as follows: Group 1 had 50% or less vascular narrowing response without ischemia; Group 2 had a vascular hyperresponsiveness of more than 50% narrowing response without ischemia; and Group 3 experienced a hyperresponsiveness with ischemia. The degree of coronary response was found to be related to smoking, inpaired glucose tolerance (IGT) and the Gensini score by multiple regression analysis. A multiple logistic analysis revealed that the Gensini score and smoking were significant predictive factors for Group 3 (odds ratio: 1.20 and 8.97). The only factor different between Group 2 and Group 1 was gender. The coronary hyperresponsiveness to ergonovine without ischemia differs from vasospastic angina in the degree of coronary atherosclerosis and smoking habits. The patients with hyperresponsiveness had similar characteristics to those with atypical chest pain rather than vasospastic angina, except for a gender difference.

Clinical observation of spontaneous anginal attacks and multivessel spasm in variant angina pectoris with normal coronary arteries: evaluation by 24-hour 12-lead electrocardiography with computer analysis

OBJECTIVES

Using a new, computerized 24-h 12-lead electrocardiographic (ECG) recording and analysis system (the EAGLE system), we sought to evaluate the clinical manifestations of ischemic episodes in patients with variant angina and normal coronary arteries.

BACKGROUND

Although the prognosis of variant angina without significant organic stenosis is generally good, the incidence of multivessel spasm, a major prognostic factor, is surprisingly high in provocation tests.

METHODS

A total of 122 patients with suspected variant or unstable angina underwent 24-h examination with the EAGLE system and two-channel Holter monitoring. Thirty patients in this group were diagnosed as having variant angina with normal or nearly normal coronary arteries. Twenty-two (73%) of these 30 patients developed anginal attacks with ST segment elevation during monitoring and were enrolled in the study.

RESULTS

The 22 patients had a total of 138 episodes of transient ST segment elevation and 13 episodes of ST segment depression. No arrhythmias were observed during ST segment depression, but 26 episodes of ST segment elevation (19%) were associated with arrhythmias: 7 with premature ventricular contractions, 3 with ventricular bigeminy, 3 with complete atrioventricular (AV) block, 1 with complete AV block and couplets of premature ventricular contractions and 12 with marked sinus bradycardia (< 45 beats/min). Ten (45%) of the 22 patients had multivessel spasm. We observed three different patterns of multivessel spasm: 1) spasm at a different site on different occasions (migratory spasm); 2) spasm that sequentially affected two different sites; 3) simultaneous spasm at more than one site. The duration of ST segment elevation was much longer in patients with sequential and simultaneous spasm than in those with single-vessel spasm, and arrhythmias were more frequent during these two types of multivessel spasm.

CONCLUSIONS

Although the prognosis of multivessel spasm is believed to be poor, this may not necessarily be so. Anginal attacks due to sequential and simultaneous multivessel spasm seem to be more dangerous than those involving single-vessel spasm or migratory multivessel spasm.

Fluctuation of spastic location in patients with vasospastic angina: a quantitative angiographic study

OBJECTIVES

This study sought to determine whether the location of coronary spastic activity may change over time in patients with persistent variant angina.

BACKGROUND

Although electrocardiographic studies have provided indirect evidence to indicate that the location of ischemia may change in patients with variant angina, it has not been tested by quantitative angiography whether the location of vasospastic activity may change over time.

METHODS

Paired ergonovine provocation tests and coronary angiography were performed at a mean (+/- SD) interval of 43 +/- 13 months apart in patients with persistent symptoms of vasospastic angina in the absence of significant atherosclerosis. A total of 87 spastic and nonspastic segments of 87 major vessels in 29 patients were analyzed by quantitative angiography at baseline, after the administration of ergonovine and after isosorbide dinitrate at the initial and follow-up tests.

RESULTS

In 13 patients (group 1), coronary spasm was observed in the same 16 coronary segments at both the initial and follow-up ergonovine provocation tests. In 16 patients (group 2), the following angiographic changes occurred between the initial and follow-up tests in 48 major vessels: Of the 23 segments that developed spasm at the initial test, 10 did not have spasm at the follow-up test; of the 25 vessels that did not demonstrate spasm on the initial test, 12 demonstrated spasm on the follow-up test (a new site of spasm). Thus, in 22 (46%) of 48 vessels, fluctuation of spastic location was observed at follow-up.

CONCLUSIONS

Quantitative coronary angiography and repeated ergonovine tests revealed that some patients with persistent vasospastic angina demonstrate fluctuation of vasospastic location, whereas others exhibit a fixed location of vasospasm. Vasospastic angina may not only be a transient disease restricted in location, but may also be a persistent and variable condition involving multiple vessels over many years.

Vasospastic angina without flow-limiting coronary lesions as a cause for aborted sudden death

Two patients resuscitated from out-of-hospital cardiac arrest were later found to have minor coronary atherosclerosis and no inducible ventricular arrhythmia. Coronary spasm was not elicited during provocative tests but occurred on introduction of the catheter in the right coronary artery and spontaneously recurred after resuscitation, leading to myocardial infarction in one patient. Both patients received an implantable cardioverter defibrillator and subsequent discharges, while receiving calcium antagonists.

Acetylcholine-induced myocardial ischemia without epicardial coronary artery spasm: a possible vasospasm of small coronary arteries--a case report

Small-vessel vasospasm has been speculated upon as a possible cause of chest pain in patients with normal-appearing coronary angiograms. In this report, a patient who experienced typical chest pain during acetylcholine testing, which caused ST segment elevation without epicardial coronary spasm, is presented. This finding suggests that small-vessel vasospasm may be involved in the induction of myocardial ischemia in patients with normal epicardial coronary arteries.

Vasotonic angina: a spectrum of ischemic syndromes involving functional abnormalities of the epicardial and microvascular coronary circulation

OBJECTIVES

The present study was undertaken to investigate the response of large and small coronary arteries in a subgroup of patients with no or minimal coronary artery disease found to have objective signs of myocardial ischemia.

BACKGROUND

Many patients apparently have normal coronary arteries despite abnormal electrocardiographic (ECG) changes during spontaneous anginal attacks or exercise stress testing.

METHODS

Twenty-five patients with no or minimal (< 30% stenosis) coronary artery disease were chosen from a pool initially selected on the basis of spontaneous anginal attacks and ST segment shifts in the anterior leads. Of these, 10 were grouped as having variant angina (at least one episode of ST elevation) and the remaining 15 as having syndrome X (exercise-induced anginal pain, ST depression and reversible thallium abnormalities). Data were compared with those obtained in 10 patients with stable angina and documented coronary artery disease. Eighteen patients with supraventricular arrhythmias and normal coronary arteries served as control patients. Patients showing focal spasm during ergonovine testing were not included in the subsequent angiographic analysis. Great cardiac vein blood flow, aortic pressure and changes in coronary artery diameter were measured at rest and 2 to 4 min after hyperventilation in the remaining study group. The same procedure was repeated after sublingual administration of 0.3 mg of nitroglycerin in eight patients (four with syndrome X and four with variant angina).

RESULTS

Hyperventilation induced diffuse epicardial coronary diameter reduction, which was marginal in control patients (9 +/- 4%) and those with coronary artery disease (5 +/- 3%) but severe (p < 0.001) in those with variant angina (28 +/- 14%) or syndrome X (25 +/- 13%). Concomitant determination of coronary blood flow showed significant (p < 0.001) decreases in those with variant angina (25 +/- 11%) and syndrome X (28 +/- 10%) but not in control patients (5 +/- 8%) or those with coronary artery disease (4 +/- 5%). Changes in great cardiac vein blood flow during hyperventilation were similar before and after nitroglycerin.

CONCLUSIONS

These findings indicate that vasoconstrictor stimuli may trigger a diffuse abnormal response of both epicardial and resistance vessels in some patients with chest pain and angiographically normal coronary arteries. Patients showing such diffuse vasoconstrictor abnormalities are suggested to have a single pathogenetic entity with a spectrum of ECG manifestations ranging from ST depression to ST elevation.

The value of exercise testing in patients with coronary artery spasm

To analyze the usefulness of a single exercise test to predict the presence of fixed obstructive coronary artery disease in patients with active coronary spasm, 91 consecutive patients with angiographically proven symptomatic coronary artery spasm who had performed a symptom-limited exercise test within the week before diagnostic coronary angiography were studied. Coronary angiography revealed significant coronary obstructions in 61 patients (67%). According to the type of angina, the prevalence of significant coronary stenosis was 53% for patients with angina at rest, 68% for those with effort angina, and 92% for those with mixed angina. Exercise-induced ST segment elevation was present in eight patients (9%), ST segment depression was seen in 37 patients (41%), and no ST abnormalities in 46 (50%). There was not a significant relationship between the ST segment response to exercise and the clinical variables assessed except for coronary anatomy. Abnormal exercise test results were significantly more frequent in patients with significant coronary obstructions than in those without significant coronary occlusions (62% versus 23%; p less than 0.01). ST elevation was not useful to predict the presence of fixed coronary lesions. However, ST depression strongly suggested the presence of underlying coronary lesions with a sensitivity of 54%, a specificity of 87%, and a positive predictive value of 89%. Using this criterion, 65% of the patients were correctly classified. The results indicate that despite the functional component of ischemia in patients with coronary spasm, ST segment depression with exercise is still a highly specific sign with a high positive predictive value for the presence of significant coronary artery disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Chest pain

The accurate diagnosis of chest pain is often difficult. We review the differential diagnosis of chest pain and the diagnostic studies used in the evaluation of chest pain syndromes. Myocardial ischemia, aortic dissection, pulmonary embolism, pericarditis, and gastroenterologic sources of chest pain are the most common. The chest X-ray, electrocardiogram, echocardiogram, heart catheterization studies, and esophageal studies are helpful diagnostically.

Impending myocardial infarction in a patient with marked left ventricular hypertrophy and normal coronary arteriogram--a case report

A middle-aged woman with long-term uncontrolled arterial hypertension developed a clinical picture of impending myocardial infarction. A normal coronary arteriogram was obtained. However, left heart catheterization showed a marked increase in left ventricular end-diastolic pressure, while left angiocardiography revealed marked left ventricular hypertrophy. She was successfully treated with a beta-blocking and calcium-antagonist agent. The present case shows that an impending myocardial infarction may occur in patients having normal coronary arteriogram but with left ventricular hypertrophy secondary to arterial hypertension.

Coronary artery spasm in the genesis of myocardial ischemia

Angina pectoris that is mainly caused by coronary artery spasm (coronary spastic angina) has 1 or more of the following characteristics: (1) the attack occurs at rest, (2) the attack is associated with ST-segment elevation on the electrocardiogram (not necessarily so in case of old myocardial infarction), (3) the attack has a variable exercise threshold, and (4) the attack is suppressed by calcium antagonists but not by beta-adrenergic blocking agents. By this criteria, coronary artery spasm is involved in the development of most angina pectoris in patients with 1-vessel disease. The role of coronary artery spasm in the development of acute myocardial infarction is still controversial. However, in this study, injection of nitroglycerin, 0.2 mg, into the totally or subtotally occluded coronary artery either released the occlusion or improved the patency in 13 of the 69 patients (18.8%) with acute transmural myocardial infarction in whom coronary arteriography was performed within 4.0 +/- 1.9 hours of the onset of symptoms. Thus, coronary artery spasm appears to play a role in the production of acute myocardial infarction in these patients.

Long-term prognosis for patients with variant angina and influential factors

Two hundred forty-five patients with variant angina were followed for an average of 80.5 months (range, 36-184 months). Survival rate at 1, 3, 5, and 10 years was 98%, 97%, 97%, and 93%, respectively. Survival rate without myocardial infarction at 1, 3, 5, and 10 years was 86%, 85%, 83%, and 81%, respectively. By univarite analysis, ST segment elevation in both the anterior and inferior electrocardiographic leads was the most important factor influencing survival, followed by use of calcium antagonists, left ventricular function, smoking, and alcohol intake. The variables that significantly correlated with survival without myocardial infarction were use of calcium antagonists, left ventricular function, extent and severity of coronary artery disease, coronary artery bypass surgery, and disease activity. Multivariate analysis using the Cox proportional hazards model showed that intake of calcium antagonists, extent and severity of coronary artery disease, and ST segment elevation in both the anterior and inferior leads were significant independent predictors of survival without myocardial infarction. We conclude that long-term prognosis for patients with variant angina is relatively good and that use of calcium antagonists improves it.

Long-term prognosis of medically treated patients with vasospastic angina and no fixed significant coronary atherosclerosis

The clinical course of 48 consecutive patients with vasospastic angina and minor coronary atherosclerosis (no stenoses greater than 50%) was analyzed during an average follow-up period of 47 months. The study group consisted of 37 men and 11 women. Patients were treated with usual doses of calcium antagonists. One patient died (2%) and three had myocardial infarctions (6%). Seventy-one percent were asymptomatic or had infrequent angina; 13% had recurrences but had periods of remission lasting at least 10 months. Only 16% had persistent angina. None of the clinical or angiographic findings at the time of diagnosis were predictive of myocardial infarction or death, and they could not separate angina-free patients from those with recurrences. Thus, vasospastic angina without fixed coronary narrowing has a good prognosis despite the possibility of recurrences. However, there is a slight risk of myocardial infarction and death. This fact should be considered if there are plans to discontinue treatment.

Multivessel coronary spasm in patients with variant angina: a study with intracoronary injection of acetylcholine

Multivessel coronary spasm has been described but its incidence in patients with variant angina still remains unclear. Thirty-three patients with variant angina were studied during coronary angiographic examination with selective intracoronary injection of acetylcholine (ACh). In all but three patients, the location of ischemia during attack was determined by the electrocardiographic findings, by exercise 201Tl myocardial scintigraphy, and by two-dimensional echocardiography during a hyperventilation test, and the coronary artery (or arteries) responsible for the attack was predicted before the study. ACh induced spasm of at least one coronary artery in all but one patient. ACh induced spasm of both the left and right coronary arteries (i.e., multivessel coronary spasm) in 24 patients: in two of the four patients who were predicted to have spasm of the left coronary artery, in six of the 11 predicted to have spasm of the right coronary artery, in 13 of the 15 predicted to have spasm of both the left and right coronary arteries, and in three of the three in whom coronary artery responsible for attack had not been predicted. This ACh-induced spasm of the left and right coronary arteries occurred separately and no patients showed hemodynamic instability during attack. In one patient in whom multivessel coronary spasm had been predicted and ACh failed to induice coronary spasm, ergonovine maleate (0.2 mg) induced spasm of both the left and right coronary arteries simultaneously, resulting in severe prolonged hypotension. Nineteen of the 25 patients in whom multivessel coronary spasm was documented showed angiographically normal or nearly normal coronary arteries after administration of nitroglycerin.(ABSTRACT TRUNCATED AT 250 WORDS)

Syndrome of coronary artery spasm of normal coronary arteries. Clinical and angiographic features

To define the clinical and angiographic features of the syndrome of spasm of angiographically normal coronary arteries, 77 patients with spasm and fixed angiographically normal coronary arteries, 77 patients with spasm and fixed coronary stenosis equal to or greater than 50% (group A) were compared with 35 patients with spasm and normal or minimally diseased coronary arteries (group B). Statistically significant differences between groups A and B were as follows: the incidence of rest angina (50.6% vs 85.7%; p less than 0.01) and mixed angina (32.5% vs 5.7%; p less than 0.01); the appearance of ST segment depression (53.3% vs 16%; p less than 0.01) and no electrocardiographic changes during stress test (35.6% vs 76%; p less than 0.01); and the tendency for arteriographically documented spasm to be focal (87.5% vs 71.4%; p less than 0.05) and to affect only one vessel (76.6% vs 57.1%; p less than 0.05). No differences were found between groups A and B in major coronary risk factors, history of previous myocardial infarction, electrocardiographic abnormalities at rest or during pain episodes, or arteries affected by spasm. Thus, angina appearing exclusively at rest is the main clinical feature of spasm of normal coronary arteries. The electrocardiogram, whether at rest or during pain episodes, has no value for predicting the existence of underlying coronary lesions, whereas stress testing does. Spasm of normal arteries tends to be more diffuse than that superimposed on organic lesions and to affect more than one artery, suggesting different mechanisms in the genesis of both types of spasm.

Chronic Chagas' heart disease presenting as an impending myocardial infarction: a case favoring the neurogenic pathogenesis concept

A 55-year-old Caucasian woman suddenly developed substernal chest pain at rest accompanied by pallor, diaphoresis, nausea, and vomiting. Physical examination was otherwise unremarkable. The resting ECG showed T-wave inversion in all anterior leads which returned to normal 24 h after the onset of the symptoms. The pain was eliminated promptly by sublingual isosorbide dinitrate. "Impending" acute myocardial infarction was diagnosed. Coronary arteriography, however, failed to reveal any change in any major coronary artery but an apical aneurysm of the left ventricle was detected. As the complement-fixation test for Chagas' disease was positive, the diagnosis of chronic Chagas' heart disease was then established. This unusual clinical manifestation of Chagas' disease is thought to be the consequence of a transient imbalance in the cardiac autonomic nervous system, which is considered to play a central role in the pathogenesis of chronic Chagas' heart disease. In addition, the present case may alert clinicians to the thus far neglected atypical chest pain, which is frequently seen in chagasic patients but whose etiology remains obscure.

Low density lipoprotein modulation of porcine coronary artery contractile response to histamine

Right coronary artery ring segments from miniature swine contracted to histamine with a force and sensitivity comparable to that reported for human right coronary artery ring segments. When the ring segments were suspended in preparations of human low density lipoprotein (LDL) the contractility was reduced. With denuded rings the contractility was significantly lower in the LDL at 1.1 X 10(-4) M histamine. With intact rings significantly less tension was generated in the LDL at concentrations greater than 6 X 10(-5) M histamine. Thus LDL attenuates the contractile response of the porcine right coronary artery to histamine.

Calcium antagonists for Prinzmetal's variant angina, unstable angina and silent myocardial ischemia: therapeutic tool and probe for identification of pathophysiologic mechanisms

The calcium antagonists provide a unique tool to reduce myocardial oxygen demand and prevent increases in coronary vasomotor tone. For patients with Prinzmetal's variant angina, diltiazem, nifedipine and verapamil are extremely effective in preventing episodes of coronary vasospasm and symptoms of ischemia. Unstable angina pectoris is a more complex pathophysiologic syndrome with episodes of ischemia due to increases in coronary vasomotor tone, intermittent platelet aggregation or alterations in the underlying atherosclerotic plaque. Each of the calcium antagonists is effective as monotherapy in decreasing the frequency of angina at rest. Nifedipine is the only calcium antagonist that has been studied in a combination regimen with beta blockers and nitrates for patients with unstable angina, and control of angina is better with the combination regimen than with either form of therapy alone. Although symptoms of myocardial ischemia in unstable angina are reduced by calcium antagonists, these agents do not seem to decrease the incidence of adverse outcomes. Antiplatelet therapy appears to improve morbidity and mortality in patients with unstable angina, suggesting that thrombus formation may play a central role in that disorder. Episodes of silent or asymptomatic myocardial ischemia, identified by ST-segment monitoring, occur in a variety of disorders of coronary disease. Among patients with Prinzmetal's variant angina and unstable angina, episodes of silent ischemia appear to be as frequent as episodes of angina and the calcium antagonists are effective in decreasing episodes of ischemia regardless of the presence or absence of symptoms. Persisting episodes of silent ischemia among patients with unstable angina despite maximal medical therapy identify patients at high risk for an early unfavorable outcome. Among patients with stable exertional angina, episodes of silent ischemia may be up to 5 times as frequent as episodes of angina, and may be due to increases in coronary vasomotor tone, transient platelet aggregation or increases in myocardial oxygen demand. Preliminary experience suggests that calcium antagonists and beta blockers are effective in decreasing episodes of silent ischemia in patients with stable exertional angina and that a combination regimen may be more effective than either form of therapy alone.

Human leucocyte antigen in variant angina

Human leucocyte antigen analysis of 45 patients with variant angina was performed to determine the presence of causative genetic factor(s). A significantly low frequency of human leucocyte antigen DQ omega 3 was found in these patients, as compared with that in 152 normal Japanese adults. There were no differences in frequencies of antigens between patients with normal and those with atherosclerotic coronaries. These data suggest that some genetic factor(s) may contribute to the pathogenesis of coronary spasm.

Production of antibodies to palytoxin: neutralization of several biological properties of palytoxin

Palytoxin stimulated arachidonic acid metabolism (in bovine aorta endothelial and smooth muscle cells, rat keratinocytes, porcine aorta endothelial cells and rat liver cells), hemolyzed rat erythrocytes and was lethal to mice when administered intraperitoneally. Serum from rabbits immunized with a conjugate in which palytoxin was covalently bound to bovine albumin through its free amino group neutralized these biologic activities of palytoxin. Ninety-nine per cent of the neutralizing activity of the immunized rabbit serum was removed after precipitation of the rabbit IgG with a goat anti-rabbit IgG.

Daily variations of ECG and left ventricular parameters at exercise in patients with anginal attacks but normal coronary arteriograms

In 21 patients with typical exercise-induced anginal pain but normal coronary arteriograms (group N) and in 14 patients with angiographically proved coronary stenosis (group C), symptom-limited ergometer exercise ECG and radionuclide angiocardiography were performed twice on two different days. Exercise-induced ST changes showed larger variations between the two exercise tests in group N than in group C ([delta ST1-delta ST2]: 0.07 +/- 0.06 mV in group N, 0.03 +/- 0.03 mV in group C, p less than 0.05). Rate pressure product and left ventricular ejection fraction at exercise also showed larger variations between the two tests in group N than in group C (p less than 0.001, p less than 0.05, respectively). However, substantial overlaps existed in some cases in the two groups. In conclusion, some of the patients with exercise-induced anginal pain but normal coronary arteriograms may have a variable threshold of exertional chest pain probably caused by variation in coronary vascular tone, and the other patients may have a fixed threshold of chest pain caused by other mechanisms.

Comparative results of percutaneous transluminal coronary angioplasty in patients with dynamic versus fixed coronary stenosis

This study compares the results of percutaneous transluminal coronary angioplasty in a group of 132 patients (group A) with fixed atherosclerotic narrowing (no spontaneous or ergonovine-provoked spasm) and in a group of 97 patients (group B) with dynamic coronary stenosis (spasm superimposed on the stenosis). All these patients underwent complete follow-up angiography. The rate of restenosis (defined as a loss of 50% of the initial gain) was significantly higher in patients in group B (dynamic coronary stenosis) than in group A (fixed narrowing) (35 versus 22%, p less than 0.05). Despite treatment with a calcium antagonist, coronary artery spasm persisted in 44% of the patients in group B and was detected for the first time in 15% of the patients in group A. Thus, in patients with dynamic coronary stenosis, the results of coronary angioplasty were less satisfactory than in patients with fixed narrowing, and in both groups coronary artery spasm was frequently (64%) superimposed on the restenosis.

The long-term outcome of patients who suffered and survived an acute myocardial infarction in the midst of recurrent attacks of variant angina

Twenty-one patients, ranging in age between 28 and 59 years, who survived hospitalization for an acute myocardial infarction in association with repetitive attacks of variant angina, were followed prospectively for 59.1 +/- 5.1 (SEM) (range 17-120) months. Four patients died, one of sudden death 17 months after admission, one of congestive heart failure at 33 months, and two of cancer at 43 and 45 months of follow-up. Three patients had four new myocardial infarctions at 22, 32, 33, and 61 months of follow-up. Six patients were readmitted for angina or other cardiac reasons. Twelve patients remained asymptomatic throughout the follow-up and one more patient was asymptomatic before and after his recurrent myocardial infarction. No relapse of variant angina was documented. Thus, the long-term course of patients with variant angina culminating in acute myocardial infarction is relatively benign, despite the highly unstable features of their initial presentation.

Late follow-up (41 to 102 months) of medically treated patients with coronary artery spasm and minor atherosclerotic coronary obstructions

From a series of 37 patients with coronary artery spasm and less than 70% diameter narrowing treated initially with verapamil and nitrates, 33 were followed up 41 to 102 months (mean 62). One patient died from carcinoma of the lung and 3 could not be traced. Before diagnosis, 3 had nontransmural myocardial infarction and 10 had either ventricular tachycardia and fibrillation or atrioventricular block. During follow-up there were no cardiac deaths or myocardial infarctions. Asymptomatic periods of more than 3 months occurred in 23 patients during follow-up: 18 with asymptomatic periods of more than 1 year were pain free at the time of study and 5 with asymptomatic periods of 3 to 6 months had infrequent pain. Ten patients had no asymptomatic periods. Symptomatic status at last review was related to initial response to therapy: 13 of 18 patients (72%) currently asymptomatic became asymptomatic with initial therapy compared with 5 of 15 patients (33%) currently experiencing pain (p = 0.06). Twenty-six patients were currently receiving therapy: 22 verapamil, 80 to 640 mg/day (mean 280), 2 nifedipine, 1 diltiazem and amiodarone and 1 isosorbide (15 were receiving additional isosorbide). Twelve patients were not receiving therapy or were receiving very low dosage therapy, including 8 with asymptomatic periods of more than 1 year. Patients with coronary spasm and less than 70% diameter narrowing treated medically have low mortality and morbidity rates over 5-year follow-up. Many have long asymptomatic periods and some may be able to stop therapy indefinitely.

An unusual presentation of variant angina

A previously well 46-year-old man presented with ventricular fibrillation as an initial complication of Prinzmetals variant angina. Coronary angiography subsequently demonstrated normal coronary arteries.