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

Coronary Artery Spasm: New Insights

Coronary artery spasm (CAS) defined by a severe reversible diffuse or focal vasoconstriction is the most common diagnosis among INOCA (ischemia with no obstructive coronary artery disease) patients irrespective to racial, genetic, and geographic variations. However, the prevalence of CAS tends to decrease in correlation with the increasing use of medicines such as calcium channel blockers, angiotensin converting enzyme inhibitor, and statins, the controlling management of atherosclerotic risk factors, and the decreased habitude to perform a functional reactivity test in highly active cardiac catheterization centers. A wide spectrum of clinical manifestations from silent disease to sudden cardiac death was attributed to this complex entity with unclear pathophysiology. Multiple mechanisms such as the autonomic nervous system, endothelial dysfunction, chronic inflammation, oxidative stress, and smooth muscle hypercontractility are involved. Regardless of the limited benefits proffered by the newly emerged cardiac imaging modalities, the provocative test remains the cornerstone diagnostic tool for CAS. It allows to reproduce CAS and to evaluate reactivity to nitrates. Different invasive and noninvasive therapeutic approaches are approved for the management of CAS. Long-acting nondihydropyridine calcium channel blockers are recommended for first line therapy. Invasive strategies such as PCI (percutaneous coronary intervention) and CABG (coronary artery bypass graft) have shown benefits in CAS with significant atherosclerotic lesions. Combination therapies are proposed for refractory cases.

A Curious Case of Coronary Vasospasm with Cardiogenic Shock: Type 1 Kounis Syndrome Complicated by Eosinophilic Myocarditis

Kounis syndrome is a rare but life-threatening form of coronary vasospasm, defined by the co-occurrence of acute coronary syndrome and hypersensitivity reaction. We present a case of refractory coronary vasospasm with aborted sudden cardiac arrest secondary to type 1 Kounis syndrome, which was complicated by eosinophilic myocarditis and cardiogenic shock. A 29-year-old Hispanic woman with history of vasospastic angina, presented with recurrent episodes of angina at rest. Initial evaluation revealed hyper-eosinophilia, elevated troponin and diffuse ST segment depression on electrocardiogram (ECG). Suddenly, she developed bradycardia and had a sudden cardiac arrest. An urgent coronary angiogram after resuscitation revealed severe multifocal vasospasm which resolved following high doses of intracoronary vasodilators. Type 1 Kounis syndrome was suspected and she was initiated on intravenous corticosteroids and anti-histamines. Subsequently, she developed cardiogenic shock, and a cardiac magnetic resonance imaging (cMRI) showed diffuse subendocardial late gadolinium enhancement (LGE) suggestive of eosinophilic myocarditis. She was diagnosed with type 1 Kounis syndrome associated with eosinophilic myocarditis. Kounis syndrome should be suspected in patients with refractory vasospastic angina. When indicated, coronary angiography should be performed with administration of intracoronary vasodilators for diagnostic and therapeutic purposes. Although, definite diagnosis of eosinophilic myocarditis requires endomyocardial biopsy, cMRI can be a crucial non-invasive method for establishing the diagnosis.

Coronary artery spasm: review and update

Coronary artery spasm (CAS), an intense vasoconstriction of coronary arteries that causes total or subtotal vessel occlusion, plays an important role in myocardial ischemic syndromes including stable and unstable angina, acute myocardial infarction, and sudden cardiac death. Coronary angiography and provocative testing usually is required to establish a definitive diagnosis. While the mechanisms underlying the development of CAS are still poorly understood, CAS appears to be a multifactorial disease but is not associated with the traditional risk factors for coronary artery disease. The diagnosis of CAS has important therapeutic implications, as calcium antagonists, not β-blockers, are the cornerstone of medical treatment. The prognosis is generally considered benign; however, recurrent episodes of angina are frequently observed. We provide a review of the literature and summarize the current state of knowledge regarding the pathogenesis of CAS.

3-year follow-up of patients with coronary artery spasm as cause of acute coronary syndrome: the CASPAR (coronary artery spasm in patients with acute coronary syndrome) study follow-up

OBJECTIVES

We sought to determine the prognosis of patients with acute coronary syndrome without culprit lesion and proof of coronary spasm during 3 years of follow-up.

BACKGROUND

Coronary artery spasm has been identified as an alternative cause for acute coronary syndrome (ACS) in patients without culprit lesion. In the CASPAR (Coronary Artery Spasm as a Frequent Cause for Acute Coronary Syndrome) study, we recently showed that ∼50% of ACS patients without culprit lesion, in whom intracoronary acetylcholine provocation was performed, had coronary spasm. However, data on prognosis in these patients are sparse.

METHODS

After 3 years of follow-up, data regarding the following end points were obtained: death (cardiac and noncardiac), nonfatal myocardial infarction, and recurrent angina leading to repeated coronary angiography. The analysis focused on patients with a culprit lesion (n = 270) and patients without a culprit lesion (n = 76) but with acetylcholine provocation (total n = 346).

RESULTS

In patients without culprit lesion, there was no cardiac death or nonfatal myocardial infarction during follow-up; 1 patient died due to a noncardiac cause. However, 38 of 76 patients reported persistent angina requiring repeated angiography in 3 cases (3.9%). Thirty of 270 patients with culprit lesion died due to a cardiac cause (11.1%) and 13 due to a noncardiac cause (4.8%). Eleven patients had nonfatal myocardial infarction (4.1%) and 27 repeated angiography due to persistent or recurrent angina (10%). Patients with a culprit lesion had a higher mortality and more coronary events compared with those without (p < 0.0005, log-rank test).

CONCLUSIONS

ACS patients without culprit lesion and proof of coronary spasm have an excellent prognosis for survival and coronary events after 3 years compared with patients with obstructive ACS. However, persistent angina represents a challenging problem in these patients, leading in some cases to repeated coronary angiography.

Administration of the Rho-kinase inhibitor, fasudil, following nitroglycerin additionally dilates the site of coronary spasm in patients with vasospastic angina

BACKGROUND

The Rho/Rho-kinase signaling pathway is known to be involved in the pathogenesis of coronary artery spasm. Previous studies reported the efficacy of the Rho-kinase inhibitor, fasudil, in the prevention and relief of coronary spasm. The usefulness of fasudil in combination with conventional vasodilating agents, however, has not been fully examined in patients with vasospastic angina.

METHODS AND RESULTS

A total of 26 patients (mean age, 61+/-11 years) with documented vasospasm in the left anterior descending coronary artery were examined by the acetylcholine stress test. Coronary diameter at the spasm site was measured at baseline and after the administration of vasodilator agents in the following order: intracoronary nitroglycerin (NTG) (300 microg), intravenous fasudil (30 mg, n=15, fasudil group) or saline (n=11, saline group), and again NTG during coronary angiography. The increase in diameter observed following the first NTG administration was found to be similar in the fasudil and saline groups (38.3+/-23.5% and 42.3+/-17.1%, respectively). The additional change in diameter on fasudil treatment (16.9+/-11.2% increase over the diameter after the first NTG administration) was significantly larger than that with saline (-2.8+/-7.6%, P<0.001). The second administration of NTG did not affect the diameter of the spasm site in either group.

CONCLUSIONS

Fasudil further dilated the site of coronary spasm, which had already been treated with NTG in patients with vasospastic angina. These findings support and extend the previous results that showed the feasibility of employing fasudil as a novel therapeutic approach for coronary spasm.

Comparison of Clinical Characteristics and Prognosis in Taiwanese Patients With Coronary Vasospastic Angina Pectoris Without Significant Fixed Coronary Artery Disease Versus Patients With Significant Fixed Coronary Artery Disease and Either Stable Angina Pectoris or Acute Coronary Syndromes

BACKGROUND

Limited information is available comparing the clinical characteristics and prognosis for patients with coronary vasospastic angina in the absence of hemodynamically significant coronary artery disease (CAD) (defined as >50% stenosis) versus patients with significant fixed CAD presenting with either stable angina pectoris (SAP) or acute coronary syndromes (ACS).

METHODS

Patients who underwent cardiac catheterization for suspected ischemic heart disease between August 1999 and February 2003 were followed clinically. For patients without hemodynamically significant CAD, a provocation test for coronary vasospasm was undertaken using a step-wise dose of intracoronary ergonovine administration.

RESULTS

A total of 1134 patients were enrolled in the final analysis and stratified into 4 diagnostically distinct groups: control group (n = 239; mild CAD without coronary vasospasm); vasospasm group (n = 284; coronary vasospastic angina pectoris without hemodynamically significant CAD); SAP group (n = 110; hemodynamically significant CAD with SAP); ACS group (n = 501; hemodynamically significant CAD with ACS). Comparison of these 4 groups revealed that the ACS patients were more likely to be male, current smokers, and have hypercholesterolemia. In addition, this group had a significantly higher incidence of typical angina pectoris, 3-vessel CAD, and lower left ventricular ejection fraction. Between-group comparison revealed that vasospasm patients had a significantly higher incidence of early morning angina pectoris. Multivariate analysis showed that current smoking was the most independent risk factor associated with the diagnosis of coronary vasospastic angina pectoris in patients without hemodynamically significant CAD. During a median follow-up period of 49 months, recurrent angina pectoris was noted in patients from the control (n = 6; 3%), SAP (n = 9; 8%), vasospasm (n = 30, 11%), and ACS groups (n = 92; 18%); with nonfatal myocardial infarction identified during follow-up in the SAP (n = 5; 5%), vasospasm (n = 3; 1%), and ACS groups (n = 37; 7%). In addition, 29 and 3 cardiac deaths occurred in the ACS and SAP groups, respectively, whereas there were no such mortalities in the control and vasospasm groups.

CONCLUSIONS

Early morning angina pectoris and cigarette smoking were the most common clinical characteristics in patients with coronary vasospasm. These patients had an excellent prognosis despite the possibility of recurrences of vasospastic angina pectoris.

Stent implantation in variant angina refractory to medical treatment

BACKGROUND

Vasospastic angina usually responds well to medical treatment.

HYPOTHESIS

The present study describes our experience in patients who received a coronary stent because of recurrent variant angina refractory to medical treatment and evaluates stent implantation as an alternative treatment.

MATERIALS AND METHODS

Between March 1998 and February 2005, recurrent variant angina was diagnosed in 22 patients admitted to our coronary care unit. Of these, five patients (22.7%), were refractory to pharmacologic treatment. Coronary angiography and coronary stents were indicated. Clinical follow-up was 29 +/- 6 months.

RESULTS

Stenting was performed during diagnostic coronary angiography in two patients. In the other three patients, the stent was implanted 24-48 h later. We observed coronary spasm recurrences proximal or distal to the stent in four patients-two during the stent implantation procedure and the other two in the coronary care unit within 48 h post angioplasty. Three patients where treated with additional stenting and the fourth patient improved with pharmacologic treatment. During follow-up three patients remained asymptomatic. The fourth patient had diffuse in-stent restenosis in the third month, and the fifth patient showed a de novo lesion in the treated segment 2 years later.

CONCLUSIONS

Stent implantation in patients with recurrent variant angina refractory to medical treatment may be an alternative treatment in carefully selected, clinically unstable patients. Spasm recurrences may occur in other segments of the treated artery, probably due to the diffuse nature of the disease. Immediate and continued surveillance is recommended because of the risk of adverse clinical events.

Is there a role for provocation testing to diagnose coronary artery spasm?

Spontaneous coronary artery spasm is an important cause of morbidity both in patients with coronary artery disease and in those with variant angina. A number of pharmacological agents have been identified which can provoke coronary artery spasm in susceptible patients. The role of provocation testing in the clinical diagnosis of coronary spasm is controversial. This is reflected by variations in the clinical use of provocation testing between specialist cardiac centres. Provocation testing appears to be a sensitive method of identifying patients with variant angina and active disease but such patients can often be diagnosed clinically. The specificity is less clear. There is little evidence that altering patient therapy on the basis of a positive test modifies prognosis. There may be a role for provocation testing in rare patients with refractory disease to identify a target site for coronary stenting. A more widespread use of these tests in patients with undiagnosed chest pain syndromes would not currently be recommended.

Limitations of medical therapy in patients with pure coronary spastic angina

OBJECTIVES

To assess the efficacy of medication for the treatment of pure coronary spastic angina, 71 consecutive patients with this diagnosis who had undergone coronary arteriography in a hospital with a follow-up of at least 2 years were studied.

METHODS AND RESULTS

All 71 patients without significant organic stenosis were treated with long-acting calcium antagonists. The disappearance of chest pain attacks while receiving medical therapy was observed in 27 patients (38%), whereas the remaining 44 patients (62%) had chest pain attacks. Of special interest, 30 patients had more than one attack per month irrespective of the administration of calcium antagonists or isosorbide dinitrate. Medical treatment showed a good response in female patients (63% vs 31%, respectively; p < 0.05) and those with ST-segment elevation during selective spasm provocation tests (63% vs 30%, respectively; p < 0.05). In contrast, patients with a longer history of chest pain attacks before hospital admission and those with diffuse spasms (77% vs 34%, respectively; p < 0.01) had poor responses to medical treatment. In this study, neither sudden death nor acute myocardial infarction was observed during the follow-up periods.

CONCLUSION

The limitations of medical therapy, including the administration of long-acting calcium antagonists, were observed in 30 of 71 patients (42%) with pure coronary spastic angina. Medical treatment was effective in only 38% of patients with pure coronary spastic angina in Japan.

Prognostic significance of the pattern of multivessel spasm in patients with variant angina

Multivessel spasm in variant angina is believed to be a major prognostic factor. Three patterns of multivessel spasm have been detected: (1) spasm at different sites on different occasions (migratory spasm); (2) spasm sequentially affecting 2 different sites (sequential spasm); and (3) simultaneous spasm at more than 1 site (simultaneous spasm). The present study investigated the prognosis based on this factor for variant angina without fixed coronary stenosis and examined the influence of multivessel spasm on cardiac events. Twenty-six patients were diagnosed as having variant angina without fixed coronary stenosis using 12-lead 24-h ECG recording system and coronary cineangiography. These patients were followed up prospectively for 57.1+/-7.6 months. Of the 26 patients 13 had single-vessel spasm, 6 had migratory multivessel spasm angina, and 7 showed sequential and/or simultaneous multivessel spasm angina. The survival free of serious cardiac events and of all cardiac events was significantly lower for patients with sequential and/or simultaneous multivessel spasm than for those with migratory multivessel spasm (p<0.05, p<0.05), whereas for patients with migratory multivessel spasm the difference comparison with single-vessel spasm did not attain statistical significance (p = ns, p = ns). The results of this study suggest that there seems to be a high-risk subgroup (i.e., sequential and/or simultaneous multivessel spasm) among patients with variant angina.

Coronary artery stent placement in patients with variant angina refractory to medical treatment

We performed a prospective study to establish the efficacy of coronary stent placement in a highly selected group of patients with focal coronary artery spasm in whom anginal attacks could not be prevented by full medical therapy. The results of this study indicate that intracoronary stent placement may represent an alternative and feasible treatment for patients with vasospastic angina refractory to aggressive medical therapy.

Frequency of systemic microvascular dysfunction in syndrome X and in variant angina

In addition to coronary vascular abnormalities, patients with syndrome X and variant angina often have systemic vascular symptoms. To determine whether these patients exhibit a generalized abnormality of vasoreactivity, we used high-resolution ultrasound to compare flow responses and endothelial function in the brachial artery in 21 patients with syndrome X, 15 patients with variant angina, and 20 healthy controls. Arterial diameter was measured at rest, after reactive hyperemia (endothelium-dependent flow-mediated vasodilation), and after sublingual glyceryl trinitrate (endothelium-independent vasodilation). The magnitude of hyperemic flow response was measured after transient forearm occlusion. Flow-mediated dilation in the brachial artery did not differ among patients with syndrome X, variant angina, and controls (2.7 +/- 2.3%, 3.8 +/- 3.5%, and 4.2 +/- 3.0%). Endothelium-independent vasodilation in the brachial artery was similar in the 3 groups (16.0 +/- 7.2%, 12.7 +/- 4.6%, and 14.8 +/- 4.9%). Despite a considerable overlap, reactive hyperemia was lower in patients with syndrome X than in patients with variant angina and controls (342+/-86% vs 466+/-184% and 452+/-104%; p < 0.05). These findings indicate that a substantial proportion of patients with syndrome X have a systemic microvascular abnormality, whereas variant angina is predominantly a segmental disorder of conduit vessels.

Cardiac arrest and sudden unexpected death in variant angina: complications of coronary spasm that can occur in the absence of severe organic coronary stenosis

Experiences in 81 patients with variant angina were reviewed with the goal of determining which clinical features were associated with the greatest risk of angina-linked cardiac arrest (13 patients) or sudden unexpected death (9 patients). The risk of occurrence of one of these actually or potentially fatal events was approximately tripled by the presence of either a history of angina-linked syncope or documentation of serious arrhythmia complicating attacks. An unexpected finding was that the risk was increased 1.5-fold by the absence of high-grade organic coronary stenosis. Cardiac arrest and sudden death are important risks of variant angina, which can occur without the presence of severe organic coronary stenosis. These risks can be reduced by adequate vasodilator therapy that includes a calcium channel blocker.

Stress testing in patients with coronary spasm: comparison of those with and without fixed coronary artery disease

Stress testing is one of the preferred noninvasive methods of identifying patients with coronary artery disease (CAD). Its value in patients with coronary artery spasm (CAS) is, however, difficult to ascertain. The authors studied 91 consecutive patients with angiographically documented CAS. All patients underwent a symptom-limited bicycle exercise test before coronary angiography. Eight patients (8.8%) showed ST-segment elevation during exercise; 37 (40.7%), ST-segment depression; and 46 (50.5%), no changes. Thirty patients had normal coronary arteries; 19, one-vessel disease; 19, two-vessel disease; and 23, three-vessel disease. Stress testing yielded abnormal results in 7 of 30 patients (23%) with no CAD and in 38 of 61 (62%) with fixed CAD (p less than 0.01). ST-segment response to exercise did not correlate with most clinical findings such as age, type of angina, duration of pain episodes, or the degree of disease activity. However, a significant correlation was found with the extent and severity of CAD. Absence of ST changes or ST-segment elevation did not differentiate those patients with or without CAD, but only 4 of 37 patients with ST-segment depression had no significant fixed lesions. In conclusion, half of the patients with CAS had a normal stress test. ST-segment elevation is an uncommon finding in these patients and does not reliably differentiate those with and without fixed CAD. The only relevant finding of stress testing in CAS patients is ST-segment depression, which strongly suggests the presence of underlying CAD.

Early evolution of symptoms and long-term prognosis in variant angina: importance of the functional component of coronary arterial disease

PURPOSE

Most investigations describing the long-term outcome of large groups of patients with variant angina pectoris have focused on such endpoints as myocardial infarction, coronary artery surgery, and death, and have asked how the risk of these events is related to the severity of existing organic coronary disease. It is also possible to ask what is the relative importance of organic and functional components in causation of symptoms and outcomes, as was done in this study.

PATIENTS AND METHODS

The early and long-term clinical course was observed in a group of 80 patients with variant angina and a low prevalence of severe organic coronary disease (diameter stenosis greater than 70 percent of one vessel in 28.3 percent, of two or more vessels in 2.7 percent). Patients were seen at the UCLA Medical Center between July 1963 and June 1985.

RESULTS

The following observations were made: Compared with those experiencing a first episode of angina at rest, subjects whose first episode of vasospastic angina occurred during strenuous effort were more likely subsequently to have a positive exercise test result and a more stable but long-term anginal course. A good initial response to vasodilator therapy indicated a likelihood of being alive and symptom-free without an intervening myocardial infarction by five years after diagnosis, which was twice the rate as if initial response to such treatment was poor. The presence or absence of severe coronary artery obstruction as detected by angiography could not be predicted from the nature or severity of angina, the historical presence of effort angina, or the occurrence of a positive result on an exercise test. The existence of severe coronary stenosis in at least one vessel was not associated with an increased incidence of myocardial infarction, cardiac arrest, or death in the first nine years after diagnosis.

CONCLUSION

These findings are consistent with the hypothesis that manifestations of ischemic heart disease in these patients were more directly caused by coronary vasospasm than by the degree of organic coronary obstruction seen by coronary arteriography. In addition, the presence of severe organic stenosis in one coronary artery did not appear to be associated with measurably increased adverse effects on clinical course or survival over the first nine years after diagnosis.

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.

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.