Provoked Coronary Spasm Predicts Adverse Outcome in Patients With Acute Myocardial Infarction

Assessment of Residual Vasospasm in Patients with Plaque Rupture or Plaque Erosion using Optical Coherence Tomography

AIMS

Coronary vasospasm is associated with acute coronary syndrome (ACS) and may persist during primary percutaneous coronary intervention (PCI). We aimed to elucidate the incidence, morphological characteristics, and prognostic impact of residual vasospasm in plaque rupture (PR) and plaque erosion (PE) lesions using optical coherence tomography (OCT).

METHODS

We enrolled 142 patients with ACS who underwent OCT-guided primary PCI. All patients received intracoronary vasodilators before OCT examination. Residual vasospasm was identified as intimal gathering and categorised as polygonal- or wavy- patterned depending on the luminal shape. A wavy pattern was defined as a curved intimal surface line. A polygonal pattern was defined as a lumen with multiple angles. The incidence of major cardiovascular events, defined as death, non-fatal myocardial infarction, stroke, and any revascularization, within 1-year of PCI was identified.

RESULTS

The prevalence of residual vasospasm in PR and PE was 15.1% (13 of 86) and 21.4% (12 of 56), respectively. Wavy pattern was the major shape of the residual vasospasm. Polygonal-patterned lumen was more frequently observed in PR than in PE (38.5 vs. 8.3 %). The polygonal-patterned lumens had significantly larger lipid arcs (257.9 vs. 78.0 °; P＜0.01), and significantly smaller areas (1.27 vs. 1.88 mm2; P=0.05) than wavy-patterned lumens. Residual vasospasm had a prognostic impact on PR but not PE at 1-year of successful primary PCI.

CONCLUSION

Considerable proportion of ACS including both PR and PE had residual vasospasm with variable morphological feature and different prognostic impact.

Ischemic Heart Disease in Young Women: JACC Review Topic of the Week

The Cardiovascular Disease in Women Committee of the American College of Cardiology convened a working group to develop a consensus regarding the continuing rise of mortality rates in young women aged 35 to 54 years. Heart disease mortality rates in young women continue to increase. Young women have increased mortality secondary to ischemic heart disease (IHD) compared with comparably aged men and similar mortality to that observed among older women. The authors reviewed the published evidence, including observational and mechanistic/translational data, and identified knowledge gaps pertaining to young women. This paper provides clinicians with pragmatic, evidence-based management strategies for young women at risk for IHD. Next-step research opportunities are outlined. This report presents highlights of the working group review and a summary of suggested research directions to advance the IHD field in the next decade.

A Practical Approach to Invasive Testing in Ischemia with No Obstructive Coronary Arteries (INOCA)

Up to 65% of women and approximately 30% of men have ischemia with no obstructive coronary artery disease (CAD; commonly known as INOCA) on invasive coronary angiography performed for stable angina. INOCA can be due to coronary microvascular dysfunction or coronary vasospasm. Despite the absence of obstructive CAD, those with INOCA have an increased risk of all-cause mortality and adverse outcomes, including recurrent angina and cardiovascular events. These patients often undergo repeat testing, including cardiac catheterization, resulting in lifetime healthcare costs that rival those for obstructive CAD. Patients with INOCA often remain undiagnosed and untreated. This review discusses the symptoms and prognosis of INOCA, offers a systematic approach to the diagnostic evaluation of these patients, and summarizes therapeutic management, including tailored therapy according to underlying pathophysiological mechanisms.

Gender Differences in the Impact of Plasma Xanthine Oxidoreductase Activity on Coronary Artery Spasm

Xanthine oxidoreductase (XOR) is the rate-limiting enzyme in uric acid (UA) production that plays a pivotal role in generating oxidative stress. Gender differences in the impact of plasma XOR activity on coronary artery spasm (CAS) remain unclear. We investigated plasma XOR activity in 132 patients suspected of having CAS (male, n = 78; female, n = 54) and who underwent an intracoronary acetylcholine provocation test. Plasma XOR activity was significantly lower in female patients compared with male patients. CAS was provoked in 36 male patients and 17 female patients, and both had significantly higher plasma XOR activity than those without. Multivariate logistic regression analysis showed that this activity was independently associated with the incidence of CAS in both sexes after adjusting for confounding factors. The optimal cut-off values for predicting CAS were lower in female patients than in male patients. Multivariate analysis demonstrated that female patients with high XOR activity exhibited a higher incidence of CAS than male patients. Plasma XOR activity was an independent predictor of the incidence of CAS in both sexes. The impact of plasma XOR activity on CAS was stronger in female patients than in male patients.

Patients with acute myocardial infarction and non-obstructive coronary arteries: safety and prognostic relevance of invasive coronary provocative tests

Aims

Functional alterations of epicardial coronary arteries or coronary microcirculation represent a frequent cause of myocardial infarction and non-obstructive coronary arteries (MINOCA). We aimed at assessing the prognostic value of intracoronary provocative tests in patients presenting with MINOCA and in which other causes of MINOCA have been excluded.

Methods and results

We prospectively evaluated patients with a diagnosis of MINOCA, excluding patients with aetiologies other than suspected coronary vasomotor abnormalities. Immediately after coronary angiography, an invasive provocative test using acetylcholine or ergonovine was performed. The incidence of death from any cause, cardiac death, and recurrence of acute coronary syndrome (ACS) was assessed at follow-up. We also assessed angina status using Seattle Angina Questionnaires (SAQ). We enrolled 80 consecutive patients [mean age 63.0 ± 10.7 years, 40 (50%) male]. Provocative test was positive in 37 (46.2%) patients without any complication. Among patients with a positive test, epicardial spasm was detected in 24 (64.9%) patients and microvascular spasm in 13 (35.1%) patients. After a median follow-up of 36.0 (range 12.0-60.0) months, patients with a positive test had a significantly higher occurrence of death from any cause [12 (32.4%) vs. 2 (4.7%); P = 0.002], cardiac death [7 (18.9%) vs. 0 (0.0%); P = 0.005], and readmission for ACS [10 (27.0%) vs. 3 (7.0%); P = 0.015] as well as a worse angina status as assessed by SAQ [Seattle score: 88.0 (33.0-100.0) vs. 100.0 (44.0-100.0); P = 0.001] when compared with patients with a negative test.

Conclusions

We demonstrate that in patients presenting with MINOCA and suspected coronary vasomotor abnormalities, a positive provocative test for spasm is safe and identifies a high-risk subset of patients.

Vasoconstrictor component of atherothrombotic culprit lesions in ST-segment elevation myocardial infarction

OBJECTIVE

The vasoconstrictor component of atherothrombotic culprit lesions in ST-elevation myocardial infarction (STEMI) patients has not been fully investigated. This study was aimed at assessing the vasoconstrictor component of atherothrombotic culprit lesions in patients with STEMI receiving primary percutaneous coronary intervention (PCI).

METHODS

A group of 100 patients with STEMI were enrolled prospectively. Baseline coronary angiography achieving normal antegrade flow was followed by 200 μg of intracoronary nitroglycerin (NTG) injection and repeat coronary angiography at the same projection view for culprit lesions was performed. End points were the changes in lesion length, reference vessel diameter, minimal lumen diameter, and diameter stenosis by quantitative coronary analysis before and after NTG injection.

RESULTS

Reference vessel diameter (2.7 ± 0.5 mm vs. 2.9 ± 0.5 mm, p < 0.001) and minimal lumen diameter (0.9 ± 0.4 mm vs. 1.2 ± 0.5 mm, p < 0.001) increased after NTG injection, whereas lesion length (24.1 ± 7.4 mm vs. 23.4 ± 7.6 mm, p = 0.001) and diameter stenosis (66.6 ± 14.8% vs. 58.3 ± 16.1%, p < 0.001) decreased. The median percentage change of diameter stenosis was -4.0% (Interquartile range: -13.8% to -1.0%), which was used as the cut-off value to divide the cohort into NTG responder or nonresponder groups accordingly. Total stent length was significantly shorter in the responder group compared with the nonresponder group (27.4 ± 11.6 mm vs. 33.7 ± 16.8 mm, p = 0.042).

CONCLUSION

This study showed the presence of a vasoconstrictor component in atherothrombotic culprit lesions in STEMI patients receiving primary PCI. Vasodilating effort by NTG may decrease stent length used for culprit lesions.

Association between Ischemic Electrocardiographic Changes during Acetylcholine Provocation Test and Long-Term Clinical Outcomes in Patients with Vasospastic Angina

Objectives Intracoronary injection of acetylcholine (Ach) has been shown to induce significant coronary artery spasm (CAS) in patients with vasospastic angina. Clinical significance and angiographic characteristics of patients with ischemic electrocardiogram (ECG) changes during the Ach provocation test are not clarified yet. Methods A total 4,418 consecutive patients underwent coronary angiography with Ach provocation tests from 2004 to 2012 were enrolled. Ischemic ECG changes were defined as transient ST-segment depression or elevation ( &gt; 1 mm) and T inversion with/without chest pain. Finally, a total 2,293 patients (28.5% of total subjects) proven CAS were enrolled for this study. Results A total 119 patients (5.2%) showed ECG changes during Ach provocation tests. The baseline clinical and procedural characteristics are well balanced between the two groups. Ischemic ECG change group showed more frequent chest pain, higher incidence of baseline spasm, severe vasospasm, multi-vessel involvement, and more diffuse spasm ( &gt; 30 mm) than those without ischemic ECG changes. At 5 years, the incidences of death, major adverse cardiac events (MACE) and major adverse cardiac and cerebral events (MACCE) were higher in the ischemic ECG change group despite of optimal medical therapy. Conclusions The patients with ischemic ECG changes during Ach provocation tests were associated with more frequent chest pain, baseline spasm, diffuse, severe and multi-vessel spasm than patients without ischemic ECG changes. At 5-years, the incidences of death, MACE and MACCE were higher in the ischemic ECG change group, suggesting more intensive medical therapy with close clinical follow up will be required.

Effect of coronary artery spasm on long-term outcomes in survivors of acute myocardial infarction

BACKGROUND

The prevalence of coronary artery spasm (CAS) inducible by intracoronary injection of acetylcholine (ACh) is high in survivors of acute myocardial infarction (AMI). Although there is a potential risk of sudden cardiac death in patients with CAS, the prognostic value of CAS was not clear. Thus, this study examined the effect of CAS on long-term prognosis in survivors of AMI in a prospective manner.

METHODS

The study included a total of 437 patients with AMI who underwent a CAS provocation test using ACh. All patients were followed prospectively for 5years or until the occurrence of the primary composite endpoint that consisted of cardiac death and acute coronary syndrome (ACS).

RESULTS

CAS was induced in 195 (45%) of the study patients. During the follow-up period, 30 patients had a recurrent event (4 had cardiac death and 26 had ACS). Kaplan-Meier estimates in time-to-first-event analysis demonstrated a similar probability of the primary endpoint in patients with and without inducible CAS (p=0.13, log-rank test). The rate of each component of the composite endpoint was also comparable between the 2 patient groups. In Cox proportional hazards risk analysis, treatment with calcium channel blockers (CCBs) negatively predicted the primary endpoints in patients with inducible CAS (HR, 0.21; 95% CI, 0.08-0.55, p<0.01).

CONCLUSIONS

The presence of inducible CAS did not increase the incidence of the cardiac events in AMI survivors. Treatment with CCBs may improve outcomes in AMI survivors with inducible CAS.

CLINICAL TRIAL REGISTRATION

URL: https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000021340, unique identifier: UMIN000018432.

Sex-Related Differences in Vasomotor Function in Patients With Angina and Unobstructed Coronary Arteries

BACKGROUND

Coronary vasomotor dysfunction is an important mechanism for angina in patients with unobstructed coronary arteries.

OBJECTIVES

The purpose of this study was to determine sex differences in the prevalence and clinical presentation of vasomotor dysfunction in a European population and to examine sex differences in the dose of acetylcholine leading to a positive acetylcholine provocation test (ACH test).

METHODS

Between 2007 and 2014, we included 1,379 consecutive patients with stable angina, unobstructed coronaries and ACH test performed for epicardial vasospasm or coronary microvascular dysfunction (CMD) due to microvascular spasm. The predictive value of sex, risk factors, symptoms, and noninvasive test results was analyzed by means of logistic regression.

RESULTS

The mean patient age was 62 years, and 42% were male. There were 813 patients (59%) with a pathological ACH test, 33% for CMD and 26% for epicardial vasospasm. A pathological test was more common in females (70% vs. 43%; p < 0.001). In a multivariable logistic regression model the sex difference was statistically significant with a female-male odds ratio for CMD and epicardial vasospasm of 4.2 (95% confidence interval: 3.1 to 5.5; p < 0.001) and 2.3 (95% confidence interval: 1.7 to 3.1; p < 0.001), respectively. Effort-related symptoms, but neither risk factors nor noninvasive stress tests, contributed to predicting a pathological test. Female patients were more sensitive to acetylcholine with vasomotor dysfunction occurring at lower ACH doses compared with male patients.

CONCLUSIONS

Vasomotor dysfunction is frequent in patients with angina and unobstructed coronaries in a European population. Female patients have a higher prevalence of vasomotor dysfunction (especially CMD) compared with male patients. A pathological ACH test was observed at lower ACH doses in women compared with men.

Clinical roles of calcium channel blockers in ischemic heart diseases

Calcium (Ca) channel blockers (CCBs) inhibit Ca²⁺ channels in the myocardium or vascular smooth muscle cells, inhibit myocardium contraction, inhibit the impulse conduction system (anti-arrhythmias) and cause vasodilation. New classifications based on subtypes of Ca channels and α1 subunits have been proposed. Moreover, CCBs have pleiotropic effects on coronary spastic angina (CSA), including variant angina, myocardial infarction (MI) and stent thrombosis (ST). Although the roles of CCBs in clinical situations remain unknown, further studies in this field are expected to broaden our understanding. In this article, we explain the clinical roles of CCBs in ischemic heart diseases, such as CSA, MI and ST, based on previous knowledge and as demonstrated in representative clinical trials.

Impact of Morning Onset on the Incidence of Recurrent Acute Coronary Syndrome and Progression of Coronary Atherosclerosis in Acute Myocardial Infarction

BACKGROUND

The relationship between time of onset of acute myocardial infarction (MI) and long-term clinical outcome has not been completely understood. We hypothesized that morning onset acute MI may be associated with adverse cardiac events.Methods and Results:This study involved 663 patients who underwent primary percutaneous coronary intervention (PCI). The main outcome measures were cardiac death, recurrent acute coronary syndrome (ACS), and re-hospitalization for heart failure. Major adverse cardiac events (MACE) were defined as a composite of individual adverse outcomes. Morning onset acute MI occurred in 212 patients (32.0%); they had higher rates of recurrent ACS (13% vs. 8%, P=0.03) and MACE (21% vs. 14%, P=0.012) than the patients with other times of onset. The PCI rate for progressive lesions was also higher than for patients with other times of onset (23% vs. 14%, P=0.013). On multivariate Cox regression analysis, morning onset was an independent predictor of recurrent ACS, MACE, and PCI for progressive lesions, with adjusted hazard ratios of 1.34 (95% CI: 1.06-2.92, P=0.030), 1.51 (95% CI: 1.02-2.23, P=0.038), and 1.58 (95% CI: 1.03-2.42, P=0.037), respectively.

CONCLUSIONS

Morning onset may be associated with increased risk of recurrent ACS and coronary atherosclerosis progression.

Variant Aldehyde Dehydrogenase 2 (ALDH2*2) Is a Risk Factor for Coronary Spasm and ST-Segment Elevation Myocardial Infarction

BACKGROUND

Mitochondrial aldehyde dehydrogenase 2 (ALDH2) plays a key role in removing toxic aldehydes. Deficient variant ALDH2*2 genotype is prevalent in up to 40% of the East Asians and reported to be associated with acute myocardial infarction (AMI). To elucidate the mechanisms underlying the association of ALDH2*2 with AMI, we compared the clinical features of AMI patients with ALDH2*2 to those with wild-type ALDH2*1/*1.

METHODS AND RESULTS

The study subjects consisted of 202 Japanese patients with acute ST-segment elevation myocardial infarction (STEMI) (156 men and 46 women; mean age, 67.3±12.0) who underwent primary percutaneous coronary intervention (PCI). In 85 patients, provocation test for coronary spasm was also done 6 month post-PCI. ALDH2 genotyping was performed by direct application of the TaqMan polymerase chain system. Of the 202 patients, 103 (51.0%) were carriers of ALDH2*2 and 99 (49.0%) those of ALDH2*1/*1. There were no differences in clinical features between ALDH2*2 and ALDH2*1/*1 carrier groups except higher frequencies of coronary spasm and alcohol flush syndrome (AFS) (88.6% vs 56.1%; P=0.001 and 94.3% vs 17.6%; P<0.001), less-frequent alcohol habit (14.6% vs 51.5%; P<0.001), and higher peak plasma creatine phophokinase levels (2224 vs 1617 mg/dL; P=0.002) in the ALDH2*2 than the ALDH2*1/*1 carrier group.

CONCLUSIONS

ALDH2*2 is prevalent (51.0%) among Japanese STEMI patients, and those with ALDH2*2 had higher frequencies of coronary spasm and AFS and more-severe myocardial injury compared to those with ALDH2*1/*1.

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.

Different characteristics of cardiac biomarkers to decide and predict the culprit lesions in patients with suspicious acute coronary syndrome

This multicenter prospective study was conducted to assess high-sensitivity troponin T (hs-TnT) and other biomarkers to decide and predict culprit lesions indicated for emergency percutaneous coronary intervention (PCI) in patients with suspicious acute coronary syndrome (ACS). We have reported Hs-TnT is the most sensitive biomarker for earlier diagnosis and decision making in patients with suspected ACS. In this study, we had conducted subanalysis investigating the usefulness for prediction of ACS culprit lesion. The patients with suspicious ACS and initially negative whole-blood rapid troponin T test, who underwent coronary angiogram (CAG), were enrolled (n = 74). Hs-TnT, quantitative assay for conventional troponin T (c-TnT), creatine kinase MB isozyme (CK-MB), and heart-type fatty acid-binding protein (H-FABP) were simultaneously measured. ACS culprit lesion was described as total occlusion, subtotal occlusion, and/or angiographical unstable lesion such as thrombosis, ulceration or irregularity. The CAG revealed that 49 cases had ACS lesions to be indicated for emergency PCI. The areas under the ROC curves and ROC-optimized cut-off of hs-TnT, c-TnT, CK-MB, and H-FABP were 0.75, 0.67, 0.68, and 0.75, respectively, and 18, 11, 2.0, and 4.6 ng/ml, respectively. In patients with total occlusion and 90–99 % of diameter stenosis (TIMI 2 or 3), hs-TnT could predict emergency PCI with significantly higher sensitivity compared with H-FABP (hs-TnT >14 ng/ml; 71 %, and H-FABP >6.2 ng/dl; 51 %, p = 0.021) and other biomarkers. Meanwhile, H-FABP displayed significant correlations with number of diseased vessels and presence of thrombotic lesion. The present study first revealed different characteristics of correlation between the angiographic culprit lesions and each cardiac biomarker. For prediction of ACS lesions requiring emergency PCI, hs-TnT had the highest sensitivity with satisfied analytical precision.

Safety of coronary reactivity testing in women with no obstructive coronary artery disease: results from the NHLBI-sponsored WISE (Women's Ischemia Syndrome Evaluation) study

OBJECTIVES

This study evaluated the safety of coronary reactivity testing (CRT) in symptomatic women with evidence of myocardial ischemia and no obstructive coronary artery disease (CAD).

BACKGROUND

Microvascular coronary dysfunction (MCD) in women with no obstructive CAD portends an adverse prognosis of a 2.5% annual major adverse cardiovascular event (MACE) rate. The diagnosis of MCD is established by invasive CRT, yet the risk of CRT is unknown.

METHODS

The authors evaluated 293 symptomatic women with ischemia and no obstructive CAD, who underwent CRT at 3 experienced centers. Microvascular function was assessed using a Doppler wire and injections of adenosine, acetylcholine, and nitroglycerin into the left coronary artery. CRT-related serious adverse events (SAEs), adverse events (AEs), and follow-up MACE (death, nonfatal myocardial infarction [MI], nonfatal stroke, or hospitalization for heart failure) were recorded.

RESULTS

CRT-SAEs occurred in 2 women (0.7%) during the procedure: 1 had coronary artery dissection, and 1 developed MI associated with coronary spasm. CRT-AEs occurred in 2 women (0.7%) and included 1 transient air microembolism and 1 deep venous thrombosis. There was no CRT-related mortality. In the mean follow-up period of 5.4 years, the MACE rate was 8.2%, including 5 deaths (1.7%), 8 nonfatal MIs (2.7%), 8 nonfatal strokes (2.7%), and 11 hospitalizations for heart failure (3.8%).

CONCLUSIONS

In women undergoing CRT for suspected MCD, contemporary testing carries a relatively low risk compared with the MACE rate in these women. These results support the use of CRT by experienced operators for establishing definitive diagnosis and assessing prognosis in this at-risk population. (Women's Ischemia Syndrome Evaluation [WISE]; NCT00832702).

A Case of Acute Myocardial Infarction With ST-Segment Elevation in a Lead Augmented Right Vector Caused by a Left Main Coronary Artery Vasospasm

Diagnosing and selecting an appropriate treatment strategy for left main coronary artery (LMCA) obstruction is very important. Although this disease is not frequently encountered, it can cause severe hemodynamic deterioration resulting in a less favorable prognosis without a suitable management approach. Another aspect of LMCA that we must not overlook is coronary artery spasm, which can be an infrequent but important cause of acute coronary syndrome. Although it is rare, LMCA can cause critical complications. In this study, we report the case of a 35-year-old female who was admitted to the hospital with a diagnosis of acute myocardial infarction with ST-segment elevation in the aVR lead caused by a left main coronary spasm that was examined on intravascular ultrasound.

Disruption of coronary vasomotor function: the coronary spasm syndrome

Abnormal coronary vasoconstriction, or coronary spasm, can be the result of several factors, including local and neuroendocrine aberrations. It can manifest clinically as a coronary syndrome and plays an important role in the genesis of myocardial ischemia. Over the past half century, coronary angiography allowed the in vivo demonstration of spasm in patients who fit the initial clinical description of the condition as reported by Prinzmetal et al. Several clinical, basic, and more recently, genetic studies have provided insight into the pathogenesis, manifestations, and therapy of this condition. It is not uncommonly encountered in patients with coronary syndromes and absence of clearly pathologic lesions on angiography. Provocation tests utilizing pharmacologic and nonpharmacologic stimuli combined with imaging (echocardiography or coronary angiography) can help make the correct diagnosis. The use of calcium channel blockers and long-acting nitrates is currently considered standard of care and the overall prognosis appears to be good. The recent discovery of genetic abnormalities predisposing to abnormal spasm of the coronaries has stimulated interest in the development of targeted therapies for the management of this condition.

Clinical classification and plaque morphology determined by optical coherence tomography in unstable angina pectoris

Unstable angina pectoris (UAP) is categorized with the Braunwald classification. However, the association of clinical presentation and plaque structure/function has not yet been elucidated in relation to cause. We used optical coherence tomography to investigate this relation. One hundred fifteen patients with primary UAP were categorized according to the Braunwald classification. Patients with class I UAP had the highest frequency of ulcers without fibrous cap disruption (p = 0.003) and the smallest minimum lumen area (class I, median 0.70 mm(2), quartiles 1 to 3 0.42 to 1.00; class II, 1.80 mm(2), 1.50 to 2.50; class III, 2.31 mm(2), 1.21 to 3.00; p <0.001). Patients with class II UAP had the highest frequency of coronary spasm (p <0.001) and the lowest frequency of thrombi (p <0.001). Patients with class III UAP had the highest frequency of plaque ruptures (p <0.001), the thinnest fibrous cap (class I, median 140 microm, quartile 1 to 3 90 to 160; class II, 150 microm, 120 to 160; class III, 60 microm, 40 to 105; p <0.001), and the highest frequency of thin cap fibroatheromas (p <0.001) and spotty calcifications (p <0.001). In conclusion, the structures/functions of culprit lesions on optical coherence tomograms differ in the Braunwald classes of UAP. Plaque vulnerability, progressive stenosis, and vasoconstriction may be related to the cause of the distinct presentations.

Current advances in the understanding of coronary vasospasm

Recent years have witnessed progress in our understanding of coronary vasospasm (CVS). It is evident that this is not only an East Asian but also a global disease associated with significant symptoms and possible lethal sequelae for afflicted individuals. A correct diagnosis depends on the understanding of pathogenesis and symptomatology of CVS. With the correct diagnosis, we can manage CVS patients effectively and promptly, providing optimal patient safety. Advances in our understanding of interactions between inflammation, endothelium, and smooth muscle cells have led to substantial progress in understanding the pathogenesis of symptoms in CVS and have provided some insights into the basic etiology of this disorder in some patient subpopulations. We look forward to a time when therapy will address pathophysiology and perhaps, even the primary etiology.

Segmental coronary endothelial dysfunction in patients with minimal atherosclerosis is associated with necrotic core plaques

BACKGROUND/OBJECTIVE

Endothelial dysfunction and atherosclerosis are systemic disorders, but are often characterised by segmental involvement and complications. A potential mechanism for local involvement early in the disease process may be related to plaque composition. This study was designed to test the hypothesis that in patients with minimal coronary atherosclerosis, coronary artery segments with abnormal endothelial function have specific plaque characteristics.

METHODS

Intravascular ultrasound (IVUS) images were obtained from 30 patients who underwent coronary endothelial function assessment. Spectral analysis of the IVUS radiofrequency data was used for assessment of plaque composition. IVUS findings of the coronary sections were compared according to the corresponding endothelial response to acetylcholine.

RESULTS

Sections with a decrease epicardial coronary arterial diameter in response to acetylcholine had smaller baseline lumen (7.5 (2.4) mm(2) vs 8.8 (3.3) mm(2), p = 0.006) but larger plaque burden (37.1% (9.4%) vs 31% (7%), p = 0.003) than sections with normal endothelial response. Sections with endothelial dysfunction had larger necrotic core plaques: 0.13 (0.03-0.33) mm(2) vs 0.0 (0.0-0.07), p<0.001 and more dense calcium: 0.03 (IQR 0.0-0.13) mm(2) vs 0.0 (0.0-0.10) mm(2), p<0.01), than those with normal endothelial response. Only necrotic core area was associated with endothelial dysfunction (p<0.001) after adjusting for other measures.

CONCLUSIONS

This study suggests that local coronary endothelial dysfunction in patients with minimal coronary atherosclerosis is associated with plaque characteristics that are typical of vulnerable plaques.

Cardiac abnormalities in acute organophosphate poisoning

BACKGROUND

Potentially lethal cardiac complications can occur in patients with acute organophosphate poisoning (OPP) and may be overlooked.

PATIENTS AND METHODS

Thirty-six patients with acute OPP were studied. Clinical features and the nature of compound involved were recorded. The QT interval was plotted against heart rate to determine the risk for Torsades de Pointes using the Fossa nomogram. Echocardiography was undertaken in 29 patients. Twenty-four-hour Holter monitoring was performed on day 1 in five patients. Thirteen died. Necropsy was performed and hearts were studied both grossly and microscopically.

RESULTS

Gross examination of the heart in 13 cases revealed cardiac discoloration or blotchiness in 12, patchy pericarditis in six, auricular thrombus in six, right ventricular hypertrophy in four, and dilatation in three. On histopathology, all 13 cases had myocardial interstitial edema and vascular congestion, eight had patchy interstitial inflammation, two had patchy myocarditis, and six had a mural thrombus. Sinus tachycardia was the most common electrocardiographic abnormality. The others were corrected QT interval prolongation, ST-T changes, U waves, and ventricular premature contractions. Echocardiography in 29 patients showed minor abnormalities in 10. On Holter monitoring, episodic tachycardia and ST-T changes were observed in four, QT prolongation in three, and episodic bradycardia in two.

CONCLUSIONS

Patchy myocardial involvement as a result of direct cardiac toxicity could be one of the factors responsible for serious cardiac complications. As myocardial involvement is patchy, it may not be manifest clinically or on echocardiography. Continuous cardiac monitoring should be undertaken to detect dynamic cardiac changes.