Increased TIMI frame counts in cocaine users: a case for increased microvascular resistance in the absence of epicardial coronary disease or spasm

Cardiovascular disease in patients with COVID-19: evidence from cardiovascular pathology to treatment

The coronavirus disease-2019 (COVID-19) caused by the novel coronavirus severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has rapidly developed into a global pneumonia pandemic. Cardiovascular disease is the major comorbidity of COVID-19 patients and is closely related to the severity of COVID-19. SARS-CoV-2 infection can directly or indirectly cause a series of cardiac complications, including acute myocardial injury and myocarditis, heart failure and cardiac arrest, arrhythmia, acute myocardial infarction, cardiogenic shock, Takotsubo cardiomyopathy, and coagulation abnormalities. Intensive research on the SARS-CoV-2-associated cardiovascular complications is urgently needed to elucidate its exact mechanism and to identify potential drug targets, which will help to formulate effective prevention and treatment strategies. Hence, this review will summarize recent progress regarding the effects of COVID-19 on the cardiovascular system and describe the underlying mechanism of cardiovascular injury caused by SARS-CoV-2.

Substance Use Disorder in the COVID-19 Pandemic: A Systematic Review of Vulnerabilities and Complications

As the world endures the coronavirus disease 2019 (COVID-19) pandemic, the conditions of 35 million vulnerable individuals struggling with substance use disorders (SUDs) worldwide have not received sufficient attention for their special health and medical needs. Many of these individuals are complicated by underlying health conditions, such as cardiovascular and lung diseases and undermined immune systems. During the pandemic, access to the healthcare systems and support groups is greatly diminished. Current research on COVID-19 has not addressed the unique challenges facing individuals with SUDs, including the heightened vulnerability and susceptibility to the disease. In this systematic review, we will discuss the pathogenesis and pathology of COVID-19, and highlight potential risk factors and complications to these individuals. We will also provide insights and considerations for COVID-19 treatment and prevention in patients with SUDs.

Assessment of Coronary Slow Flow, Cystatin C, and Body Mass Index in Female Candidates for Diagnostic Coronary Artery Angiography

Introduction: Evidence indicates that the associations between coronary slow flow (CSF), cystatin C (Cys C), and body mass index (BMI) are unclear. Therefore, the purpose of our study was to determine the association among the above-mentioned parameters in female patients. Methods: This was a descriptive-analytical study and the participants were those who were referred to the Shohada Cardiovascular Center of Urmia in 2015-2016. The participants were measured by a quantitative method under angiography (corrected TIMI frame count, CTFC) for CSF assessment, followed by evaluating physiological indices and the serum Cys C by the enzyme-linked immunosorbent assay. Finally, Pearson correlation coefficient test was used to analyze the correlations among CTFC, Cys C, and BMI, and a significance level of P < 0.05 was used for this test. Results: Sixty-six female patients (mean age: 57.01±8.25 years) took part in this study. The correlations among Cys C with CTFC, and BMI (r=-0.189, P=0.128 and r=0.044, P=0.724, respectively) and BMI with CTFC (r=-0.178, P=0.153) were not meaningful in female patients’ who were candidates for angiography. Conclusion: In general, the results suggested that serum Cys C cannot be considered as a predictive biomarker for the prognostic stratification of CSF and BMI in female patients aged 34-73 years who were candidates for angiography.

β-Blockers, Cocaine, and the Unopposed α-Stimulation Phenomenon

Cocaine abuse remains a significant worldwide health problem. Patients with cardiovascular toxicity from cocaine abuse frequently present to the emergency department for treatment. These patients may be tachycardic, hypertensive, agitated, and have chest pain. Several pharmacological options exist for treatment of cocaine-induced cardiovascular toxicity. For the past 3 decades, the phenomenon of unopposed α-stimulation after β-blocker use in cocaine-positive patients has been cited as an absolute contraindication, despite limited and inconsistent clinical evidence. In this review, the authors of the original studies, case reports, and systematic review in which unopposed α-stimulation was believed to be a factor investigate the pathophysiology, pharmacology, and published evidence behind the unopposed α-stimulation phenomenon. We also investigate other potential explanations for unopposed α-stimulation, including the unique and deleterious pharmacologic properties of cocaine in the absence of β-blockers. The safety and efficacy of the mixed β-/α-blockers labetalol and carvedilol are also discussed in relation to unopposed α-stimulation.

Thrombin activatable fibrinolysis inhibitor : its role in slow coronary flow

BACKGROUND

The slow coronary flow (SCF) phenomenon is characterized by slow progression of angiographic contrast medium in the coronary arteries in the absence of stenosis in the epicardial vessels. The pathophysiological mechanisms of SCF phenomenon remain uncertain. Several hypotheses, however, have been suggested for SCF phenomenon, including an early form of atherosclerosis, small vessel dysfunction, dilatation of coronary vessels, imbalance between vasoconstrictor and vasodilatory factors, platelet function disorder, and inflammation. Atherosclerosis and inflammation are the most accepted mechanisms for the pathogenesis of SCF. Thrombin activatable fibrinolysis inhibitor (TAFI) was described as a new inhibitor of fibrinolysis recently and plays an important role in coagulation and fibrinolysis. In previous studies, the role of TAFI was associated with inflammation and evolution of atherosclerosis in coronary artery disease. There are no data available about TAFI levels in patients with SCF phenomenon investigated by angiography. Our goal was to evaluate TAFI antigen (Ag) levels in patients with SCF and to determine the association of the TAFI Ag level with traditional cardiovascular risk factors in our study.

METHODS

The study group constituted 41 patients with angiographically confirmed SCF and 46 patients with normal coronary flow as the control group. The TAFI Ag levels of each patient were determined.

RESULTS

Between the control and study group, a statistical difference in the levels of TAFI Ag (p < 0.05) was observed. The TAFI Ag level was significantly higher in the SCF group than the control group (132.21 ± 21.14 versus 122.15 ± 21.59).

CONCLUSION

We have demonstrated that TAFI might be a risk factor for the development of SCF independently of conventional cardiovascular risk factors. In addition, TAFI Ag levels were positively correlated with C-reactive protein (CRP) known as an acute phase reactant. Our findings support the reports of previous studies that increased TAFI levels may be associated with inflammation. Further large studies are required to evaluate the importance of TAFI antigen levels in relation to the development of SCF.

Corrected thrombolysis in myocardial infarction frame count and ejection fraction in patients undergoing primary percutaneous coronary intervention for myocardial infarction

BACKGROUND

This study aimed to assess the associations between corrected thrombolysis in myocardial infarction frame count (CTFC) of the infarct-related artery (IRA) and ejection fraction (EF) after three-six months in patients who underwent primary percutaneous coronary intervention (PPCI) for ST segment elevation myocardial infarction (STEMI).

METHODS

CTFC was determined by a digital system for 78 patients. EF was measured through Simpson's method upon discharge and three-six months later. The subjects were divided into two groups of CTFC ≤ 20 (n = 54) and CTFC > 20 (n = 24). Association between CTFC and EF were then specified.

RESULTS

CTFC ≤ 20 and CTFC > 20 were present in 69.2% and 30.8% of the patients, respectively. There was no significant difference between the two groups regarding baseline characteristics. EF at the time of discharge was 42.1% ± 10.2% and 43.5% ± 11.4% in groups with CTFC ≤ 20 and > 20, respectively. There was no significant association between EF at discharge and CTFC (P = 0.611). After three months, EF changed to 49.6% ± 8.7% and 41.6 ± 12.4% in the groups with CTFC ≤ 20 and CTFC > 20, respectively. Three months after PPCI, EF and CTFC had a significant relation (P = 0.007). Cumulative number and percentage of shock and death were 3 (3.8%) and 2 (2.6%), respectively.

CONCLUSION

Lower CTFC of the infarct-related artery in patients undergoing PPCI for STEMI was associated with higher left ventricular ejection fraction after three months.

Use of the TIMI frame count in the assessment of coronary artery blood flow and microvascular function over the past 15 years

Since its introduction, the TIMI frame count method has contributed to the understanding of the pathophysiology of coronary artery disease. In this article, the evolution of the TFC method and its applicability in the assessment of various therapeutic modalities are described.

Increased plasma C-reactive protein and interleukin-6 concentrations in patients with slow coronary flow

BACKGROUND

Slow coronary filling of epicardial coronary arteries in the absence of stenosis is not infrequently detected finding during routine coronary angiography. There is mounting evidence suggested that an inflammatory process play an important role in atherosclerotic pathogenesis appeared in different clinical settings. However, the possible association between inflammation and slow coronary flow (SCF) has not been investigated. We examined whether the increased inflammatory markers are present in patients with SCF.

METHODS

Forty-two patients with SCF detected by coronary angiography via the Thrombosis In Myocardial Infarction (TIMI) frame count method were enrolled in this study. The plasma concentration of high-sensitivity C-reactive protein (CRP) and interleukin-6 (IL-6) were evaluated using commercial available kits. Data were compared with 30 control subjects with angiographically normal coronary flow.

RESULTS

There are no differences regarding clinical characteristics between the 2 groups. The data showed, however, that plasma CRP and IL-6 concentrations were higher in patients with SCF compared with normal control subject (CRP: 0.27 +/- 0.16 vs. 0.22 +/- 0.11mg/l; and IL-6: 8.7 +/- 0.8 vs. 5.4 +/- 0.4pg/ml, p < 0.01 respectively). In addition, mean TIMI frame count was positively correlated with plasma CRP and IL-6 concentrations (CRP: gamma = 0.551; IL-6: gamma = 0.573, p < 0.01 respectively).

CONCLUSIONS

Plasma concentration of CRP and IL-6 concentrations increased, and was positive correlated with TIMI frame count in patients with SCF compared with normal coronary flow subject. Therefore, whether the increased inflammatory markers are related to the pathogenesis of SCF in these patients deserved further investigation.

Transient left ventricular apical ballooning after cocaine use: is catecholamine cardiotoxicity the pathologic link?

We describe a patient who developed acute chest pain after using cocaine and had ST-segment elevation in the anterior leads on electrocardiography with mild elevation of cardiac enzymes. Cardiac catheterization showed normal coronary arteries with no coronary vasospasm. Left ventricular angiography revealed typical ballooning of the left ventricular apex during systole with an estimated left ventricular ejection fraction of 25%. The symptoms improved during the next few hours, and follow-up echocardiography 4 days later showed complete resolution of the left ventricular dysfunction. Transient left ventricular apical ballooning (LVAB) was diagnosed. To our knowledge, LVAB (also known as Takotsubo cardiomyopathy or "broken heart syndrome") has not been reported previously in association with cocaine use. We discuss the possible pathophysiologic link between LVAB and cocaine-induced cardiotoxicity.

Is slow coronary flow associated with inflammation?

Cardiologists are familiar with the phenomenon of slow progression of angiographic contrast in the coronary arteries in the absence of stenosis in the epicardial vessels in some patients presenting with chest pain. This phenomenon is called as coronary slow flow phenomenon, and firstly described in 1972, while it remains scantily studied. The pathophysiological mechanisms of coronary slow flow phenomenon remain uncertain. Several hypotheses however, have been suggested for slow coronary flow phenomenon, including a form of early phase of atherosclerosis, small vessel dysfunction, Hagen-Poiseuille's equation model, imbalance between vasoconstrictor and vasodilatory factors, and platelet function disorder. More recently, there has been mounting evidence that inflammation plays an important role in the initiation, development as well as evolution of atherosclerosis, suggesting that atherosclerosis is an inflammation disease. New evidence has also indicated that inflammation may be involved in the development of slow coronary flow phenomenon. Coronary slow flow phenomenon is an important clinical entity because it may be the cause of angina at rest or during exercise, acute myocardial infarction, and hypertension. Despite the good prognosis of this kind of patients, the chronic, frequent nature of the persistent uncomfortable chest can significantly impair the quality of life. Whether this is really a new kind of coronary disease involving in inflammation, however, is still unknown and deserves further investigation.

Normal angiogram in acute coronary syndromes: the underestimated role of alternative substrates of myocardial ischemia

The study is aimed at evaluating the real incidence of normal coronary arteries and the role of alternative substrates of myocardial ischemia in patients with acute coronary syndrome (ACS) but with no coronary artery disease (CAD) in a real world secondary care public hospital. The medical records of 941 patients undergoing coronary arteriography for ACS within 48 h of onset between January 1st 2000 and November 1st 2003 were critically reviewed. In 70 patients (7.4%, 35 males, mean age 60 +/- 17.2 years) no CAD was documented. Alternative substrates of acute myocardial ischemia included coronary artery anomalies (7 patients, 10%), coronary spasm (10 patients, 14.3%), spontaneous coronary dissection (2 patients, 2.8%), paradoxical embolism through a patent foramen ovale (4 patients, 5.7%), embolism from left atrium or calcified aortic valve (4 patients, 5.7%), imbalance between oxygen demand and supply (20 patients, 28.5%), mitral valve prolapse (11 patients, 15.7%). No alternative substrates were found in 12 patients (17.1%). Patients with no CAD are more frequently female and younger. Absence of CAD is an uncommon finding in patients undergoing coronary artery angiography for ACS.

The no-flow phenomenon during diagnostic coronary angiography

OBJECTIVES

Slow flow of dye in epicardial coronary arteries is not an infrequent finding in patients during routine coronary angiography. The extreme form of this phenomenon, namely, no flow or Thrombolysis in Myocardial Infarction (TIMI) 0-1, is very uncommon with life-threatening consequences. We consider the present report as the first one, to our knowledge, that describes this angiographic entity and how prompt recognition and adequate management prevent certain death in this population.

DESIGN, SETTING, AND PATIENTS

Retrospective review of the cardiac catheterization laboratory database at our medical center. Out of 5700 cardiac catheterizations performed by the authors during the past 5 years, 10 cases (0.17%) were identified as having no flow or very slow flow during their routine diagnostic coronary angiogram.

CASE ANALYSIS

The no-flow phenomenon occurred during the first coronary injection in the left coronary system. We specifically emphasize that none of these cases was a consequence of inadvertent air injection, vasospasm, or coronary dissection. In 80% of our cases, flow was completely absent (TIMI 0), and in two cases (20%) it was very slow and never filling the distal vessel (TIMI 1). Despite immediate recognition and prompt maneuvers and treatment with intracoronary vasodilator administration, 60% of these patients progressed to full cardiopulmonary arrest with all of them having extended cardiopulmonary resuscitation (CPR) and pharmacological treatment. Only one patient required intra-aortic balloon pump (IABP) support and temporary pacemaker. All patients recovered completely with no clinical consequences. Characteristics of patients with this complication are described, and several possible etiologies are analyzed.

CONCLUSIONS

Definite conclusions for the reason of the no-flow phenomenon are not possible at present, despite multiple different theories that could explain it. What is important from the clinical standpoint is that, although rare, it is a potentially life-threatening condition during diagnostic coronary angiography that should be recognized and aggressively treated. We consider the present report as the first one, to our knowledge, that describes this angiographic entity, and how prompt recognition and adequate management prevents certain death in this population.

Increased thrombolysis in myocardial infarction frame count in patients with myocardial infarction and normal coronary arteriogram: a possible link between slow coronary flow and myocardial infarction

BACKGROUND

Thrombolysis in myocardial infarction (TIMI) frame count is a simple clinical tool for assessing quantitative indexes of coronary blood flow. This technique counts the number of cineangiographic frames from initial contrast opacification of the proximal coronary artery to opacification of distal arterial landmarks. We hypothesized that patients with normal coronary artery (NCA) and myocardial infarction (MI) might have impaired coronary flow. Accordingly, we assessed the TIMI frame counts of patients with NCA and MI and compared to patients with NCA and without MI.

MATERIALS AND METHOD

This retrospective study included consecutive patients with MI and who were found to have normal coronary angiograms performed between 1999 and 2003. Fifty patients (group I) with NCA and MI were enrolled in the study. Fifty consecutive patients with NCA and without MI were also enrolled in the study as control group (group II). Mean time interval between MI and coronary angiography was 6 +/- 2 days.

RESULTS

There were statistically significant differences between groups I and II in respect to gender (11 females (22%) versus 22 females (44%), p = 0.003, respectively) and smoking status (62% (31/50) versus 38% (19/50), p = 0.02). Comparison of TIMI frame counts between two groups revealed that group I patients had significantly higher TIMI frame counts than group two patients for all three coronary arteries (LAD: 40 +/- 12 versus 23 +/- 7, Cx: 47 +/- 14 versus 27 +/- 7, RCA: 36 +/- 10 versus 26 +/- 10, respectively, p < 0.001 for all). Smokers were significantly younger when compared to non-smokers (44 +/- 5 years versus 51 +/- 9 years, p = 0.008, respectively). TIMI frame counts of smokers did not significantly differ from those of non-smokers in group I patients. There were statistically significant differences between smokers and non-smokers in group II patients regarding TIMI frame counts for all three coronary arteries (LAD: 29 +/- 7 versus 18 +/- 3, LCX: 34 +/- 10 versus 22 +/- 4, RCA: 34+ /- 13 versus 20 +/- 4, respectively, p < 0.001 for all).

CONCLUSION

We have shown that patients with MI and NCA have higher TIMI frame counts for all coronary arteries when compared to patients without MI and NCA. Absence of difference between smokers and non-smoker in the myocardial infarction group in respect to TIMI frame count, has suggested that smoking does not lead to further increase of TIMI frame counts. On the other hand, in patients without MI and with NCA, smokers have higher TIMI frame counts than non-smokers have.