Elevated plasma endothelin-1 levels in coronary sinus during rapid right atrial pacing in patients with slow coronary flow

Could Pan-Immune-Inflammation Value be a Marker for the Diagnosis of Coronary Slow Flow Phenomenon?

Inflammation plays a key role in the pathogenesis of the coronary slow flow phenomenon (CSFP). The newly developed inflammatory marker, pan-immune-inflammation value (PIV), is associated with adverse cardiovascular events. This study investigated the predictive value of PIV for diagnosing CSFP in comparison to other inflammation-based markers. A total of 214 patients, 109 in the CSFP group and 105 in the normal coronary flow (NCF) group, were retrospectively included in the study. Coronary flow was calculated using the Thrombolysis in Myocardial Infarction frame count method. In addition to PIV, other inflammatory markers such as neutrophil-lymphocyte ratio, platelet-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII) were calculated for the patients. The average age of patients was 50.3 ± 8.4, with a male ratio of 55.1%. Compared to the NCF group, patients in the CSFP group had higher levels of hyperlipidemia, glucose, triglyceride, NLR, PLR, SII, and PIV, while their high-density lipoprotein cholesterol (HDL-C), was lower (p < 0.05). Logistic regression analysis demonstrated that HDL-C, glucose, triglyceride, and PIV were independent predictor factors for CSFP (p < 0.05). PIV is a strong and independent predictor factor for CSFP and superior in predicting CSFP compared to other inflammatory markers.

Analysis of Risk Factors and Construction of a Predictive Model for Readmission in Patients with Coronary Slow Flow Phenomenon

Background

Coronary slow flow phenomenon (CSFP) is a phenomenon in which distal vascular perfusion is delayed on angiography, but coronary arteries are not significantly narrowed and there is no other organic cardiac disease. Patients with CSFP may be repeatedly readmitted to the hospital because of chest pain or other symptoms of precordial discomfort, and there is a risk of adverse events. In order to investigate the risk factors affecting the readmission of CSFP patients, a prediction model was constructed with the aim of identifying patients at risk of readmission at an early stage and providing a reference for further clinical intervention.

Methods

In this study, we collected clinical data from 397 CSFP patients between June 2021 and January 2023 in Xinjiang Medical University Hospital. Telephone follow-up clarified whether the patients were readmitted to the hospital. A predictive model for readmission of CSFP patients was constructed using multifactorial logistic regression. Nomogram was used to visualize the model and bootstrap was used to internally validate the model. ROC, DCA and Calibration curve were plotted to evaluate the calibration and discriminative ability of the column line graphs, respectively. Calibration and resolution of the column line graphs, respectively.

Results

A total of 34 of 397 CSFP patients experienced readmission. Smoking history, creatine kinase isoenzyme-MB, total cholesterol, and left ventricular ejection fraction were the predictors of readmission in patients with CSFP. The area under the curve of the Nomogram model was 0.87, which indicated that the model had good predictive ability and differentiation, and the DCA and Calibration curves also indicated that the model had good consistency and was clinically useful.

Conclusion

A readmission prediction model for patients with CSFP may facilitate early identification of patients at potential risk for readmission and timely interventional therapy to improve patient prognosis.

Anti-Anginal Efficacy of Zibotentan in the Coronary Slow-Flow Phenomenon

BACKGROUND

Patients with coronary microvascular disorders often experience recurrent angina for which there are limited evidence-based therapies. These patients have been found to exhibit increased plasma levels of endothelin; thus, selective endothelin-A (Et-A) receptor blockers such as zibotentan may be an effective anti-anginal therapy in these patients. The study evaluated the impact of a 10 mg daily dose of zibotentan on spontaneous angina episodes in patients with the coronary slow-flow phenomenon who had refractory angina (i.e., experiencing angina at least three times/week despite current anti-anginal therapy).

METHODS

Using a randomized, double-blind, placebo-controlled, crossover trial design with 4-week treatment periods, 18 patients (63.2 ± 9.9 years, 33% females) were recruited. The primary endpoint was angina frequency as measured by an angina diary, with secondary endpoints including nitrate consumption, angina duration/severity and the Seattle Angina Questionnaire (SAQ) domains.

RESULTS

During the 4 weeks of therapy, angina frequency significantly improved with zibotentan therapy (placebo 41.4 (58.5) vs. zibotentan 29.2 (31.6), p < 0.05), and sublingual nitrate consumption significantly reduced (placebo 11.8 (15.2) vs. zibotentan 8.8 (12.9), p < 0.05.

CONCLUSIONS

Zibotentan improved the frequency of spontaneous angina episodes and reduced sublingual nitrate consumption in patients unresponsive to standard anti-anginal therapy.

Single Nucleotide Polymorphisms in Coronary Microvascular Dysfunction

Coronary microvascular dysfunction is an underdiagnosed pathologic process that is associated with adverse clinical outcomes. There are data to suggest that coronary microvascular dysfunction, in some cases, may be genetically determined. We present an updated review of single nucleotide polymorphisms in coronary microvascular dysfunction.

Coronary slow flow research: a bibliometric analysis

BACKGROUND

Studies on coronary slow flow are receiving increasing attention, but objective evaluations are still lacking. The purpose of this study was to visualize the current status and research hotspots of coronary slow flow through bibliometric analysis.

METHODS

All relevant publications on coronary slow flow from 2003 to 2022 were extracted from the Web of Science Core Collection database and analyzed by VOSviewer and CiteSpace visualization software. Year of publication, journal, country/region, institution, and first author of each paper, as well as research hotspots were identified.

RESULTS

A total of 913 publications were retrieved. The journal with the most publications was Coronary Artery Disease. The country/region with the most publications was Turkey, followed by China and the United States. The institution with the largest publication volume was Turkey Specialized Higher Education Research Hospital. The author with the largest publication volume was Chun-Yan Ma from China. Keyword analysis indicated that "treatment and prognosis", "pathogenesis and risk factors" and "diagnosis" were the clustering centers of coronary slow flow, and the research hotspots gradually changed with time, from pathogenesis to treatment and prognosis.

CONCLUSION

Future research will focus on the search for effective and non-invasive detection indicators and treatments of coronary slow flow. Collaboration needs to be enhanced between different institutions or countries/regions, which would improve clinical outcomes for patients with coronary slow flow.

Drug repurposing-a promising approach for patients with angina but non-obstructive coronary artery disease (ANOCA)

In today's era of individualized precision medicine drug repurposing represents a promising approach to offer patients fast access to novel treatments. Apart from drug repurposing in cancer treatments, cardiovascular pharmacology is another attractive field for this approach. Patients with angina pectoris without obstructive coronary artery disease (ANOCA) report refractory angina despite standard medications in up to 40% of cases. Drug repurposing also appears to be an auspicious option for this indication. From a pathophysiological point of view ANOCA patients frequently suffer from vasomotor disorders such as coronary spasm and/or impaired microvascular vasodilatation. Consequently, we carefully screened the literature and identified two potential therapeutic targets: the blockade of the endothelin-1 (ET-1) receptor and the stimulation of soluble guanylate cyclase (sGC). Genetically increased endothelin expression results in elevated levels of ET-1, justifying ET-1 receptor blockers as drug candidates to treat coronary spasm. sGC stimulators may be beneficial as they stimulate the NO-sGC-cGMP pathway leading to GMP-mediated vasodilatation.

Coronary Slow Flow Is Not Diagnostic of Microvascular Dysfunction in Patients With Angina and Unobstructed Coronary Arteries

Background Guidelines recommend that coronary slow flow phenomenon (CSFP), defined as corrected thrombolysis in myocardial infarction frame count (CTFC) >$$ > $$27, can diagnose coronary microvascular dysfunction (CMD) in patients with angina and nonobstructed coronary arteries. CSFP has also historically been regarded as a sign of coronary endothelial dysfunction (CED). We sought to validate the utility of CTFC, as a binary classifier of CSFP and as a continuous variable, to diagnose CMD and CED. Methods and Results Patients with angina and nonobstructed coronary arteries had simultaneous coronary pressure and flow velocity measured using a dual sensor-tipped guidewire during rest, adenosine-mediated hyperemia, and intracoronary acetylcholine infusion. CMD was defined as the inability to augment coronary blood flow in response to adenosine (coronary flow reserve <2.5) and CED in response to acetylcholine (acetylcholine flow reserve ≤1.5); 152 patients underwent assessment using adenosine, of whom 82 underwent further acetylcholine testing. Forty-six patients (30%) had CSFP, associated with lower flow velocity and higher microvascular resistance as compared with controls (16.5±$$ \pm $$6.9 versus 20.2±$$ \pm $$6.9 cm/s; P=0.001 and 6.26±$$ \pm $$1.83 versus 5.36±$$ \pm $$1.83 mm Hg/cm/s; P=0.009, respectively). However, as a diagnostic test, CSFP had poor sensitivity and specificity for both CMD (26.7% and 65.2%) and CED (21.1% and 56.0%). Furthermore, on receiver operating characteristics analyses, CTFC could not predict CMD or CED (area under the curve, 0.41 [95% CI, 0.32%-0.50%] and 0.36 [95% CI, 0.23%-0.49%], respectively). Conclusions In patients with angina and nonobstructed coronary arteries, CSFP and CTFC are not diagnostic of CMD or CED. Guidelines supporting the use of CTFC in the diagnosis of CMD should be revisited.

The Systemic Immune-Inflammation Index May Predict the Coronary Slow Flow Better Than High-Sensitivity C-Reactive Protein in Patients Undergoing Elective Coronary Angiography

Methods

A total of 197 patients (102 patients with CSF; 95 patients with normal coronary flow) were included in this retrospective study. Clinical and angiographic characteristics of patients were obtained from hospital records.

Results

Patients with CSF had higher SII, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte (PLR), and high-sensitivity C-reactive protein (hsCRP) levels compared with the control group. Body mass index (p=0.022, OR 1.151, 95% CI 1.121–1.299), low-density lipoprotein (p=0.018, OR 1.028, 95% CI 1.005–1.052), hsCRP (p=0.044, OR 1.161, 95% CI 1.004–1.343), and SII (p < 0.001, OR 1.015, 95% CI 1.003–1.026) were independent predictors of CSF in the multivariable analysis. The optimal cutoff value of SII in predicting CSF was >877 in ROC curve analysis (p < 0.001, AUC = 0.892, 95% CI 0.848–0.936). This cutoff value of SII predicted the CSF with a sensitivity of 71.5% and specificity of 92.4%. Spearman correlation analysis showed a positive correlation between the mean TFC value and PLR, NLR, hsCRP, and SII.

Conclusions

SII may be used as a better indicator for the prediction of CSF than hsCRP.

The relationship between triglyceride/high-density lipoprotein cholesterol ratio and coronary slow-flow phenomenon

In this study, we aimed to investigate the relationship between high triglyceride (TG)/high-density lipoprotein cholesterol (HDL-C) ratio and coronary slow flow phenomenon (CSFP) in patients undergoing elective coronary angiography for suspected coronary artery disease. This prospective study included a total of 84 CSFP patients and 83 controls with normal coronary flow, as evidenced by coronary angiography. The Thrombolysis in Myocardial Infarction (TIMI) frame count (TFC) was used to measure the coronary blood flow velocity. The lipid profiles were analyzed and TG/HDL-C ratio were calculated dividing absolute TG levels by absolute HDL-C levels in peripheral blood. The median TG/HDL-C ratio was higher in the CSFP group than the control group (3.4 [2.6 to 4.9] vs. 2.3 [1.8 to 3], respectively; p < 0.001). The multivariate logistic regression analysis revealed that TG/HDL-C ratio was an independent predictor of CSFP (odds ratio [OR] 1.78, 95% confidence interval [CI] 1.59-2.32; p = 0.001) and TG/HDL-C ratio was positively correlated with the TFC in the CSFP group (r = 0.311, p < 0.001). The area under the receiver operating characteristic curve of TG/HDL-C for the diagnosis of CSFP was 0.73 (95% CI 0.65-0.81; p < 0.001). If a cut-off value of 2.75 was used, higher levels of TG/HDL-C ratio could predict the presence of CSFP with 72% sensitivity and 71% specificity. Our study results suggest that TG/HDL-C ratio is associated with CSFP and may be a useful biomarker for predicting CSFP and its severity.

Slow Coronary Flow: Pathophysiology, Clinical Implications, and Therapeutic Management

Coronary slow flow (CSF) is an angiographic phenomenon with specific epidemiologic characteristics, associated clinical presentation, and prognosis. Although patients with CSF are diagnosed as having "normal coronary arteries," it seems appropriate to consider CSF as a distinct disease entity requiring specific treatment. The patient with CSF is usually male, smoker, obese, with a constellation of risk factors suggestive of metabolic syndrome. Unstable angina is the most common clinical presentation, with recurrent episodes of chest pain at rest associated with electrocardiographic changes often requiring readmission and reevaluation. Regarding definition and diagnosis, interventionists should first exclude possible "secondary" causes of CSF, use objective means for definition and then differentiate from other similar conditions such as microvascular angina. Although the phenomenon is generally benign, patients with CSF are severely symptomatic with recurrent episodes of chest pain and poor quality of life. Furthermore, acute presentation of the phenomenon is commonly life-threatening with ventricular tachyarrhythmias, conduction abnormalities, or cardiogenic shock. Acute treatment of CSF includes, but is not restricted to, intracoronary infusion of dipyridamole, adenosine, or atropine. Chronic management of patients with CSF encompasses dipyridamole, diltiazem, nebivolol, telmisartan, and/or atorvastatin associated with amelioration of angina symptoms, improved quality of life, and good prognosis.

Genetic dysregulation of endothelin-1 is implicated in coronary microvascular dysfunction

AIMS

Endothelin-1 (ET-1) is a potent vasoconstrictor peptide linked to vascular diseases through a common intronic gene enhancer [(rs9349379-G allele), chromosome 6 (PHACTR1/EDN1)]. We performed a multimodality investigation into the role of ET-1 and this gene variant in the pathogenesis of coronary microvascular dysfunction (CMD) in patients with symptoms and/or signs of ischaemia but no obstructive coronary artery disease (CAD).

METHODS AND RESULTS

Three hundred and ninety-one patients with angina were enrolled. Of these, 206 (53%) with obstructive CAD were excluded leaving 185 (47%) eligible. One hundred and nine (72%) of 151 subjects who underwent invasive testing had objective evidence of CMD (COVADIS criteria). rs9349379-G allele frequency was greater than in contemporary reference genome bank control subjects [allele frequency 46% (129/280 alleles) vs. 39% (5551/14380); P = 0.013]. The G allele was associated with higher plasma serum ET-1 [least squares mean 1.59 pg/mL vs. 1.28 pg/mL; 95% confidence interval (CI) 0.10-0.53; P = 0.005]. Patients with rs9349379-G allele had over double the odds of CMD [odds ratio (OR) 2.33, 95% CI 1.10-4.96; P = 0.027]. Multimodality non-invasive testing confirmed the G allele was associated with linked impairments in myocardial perfusion on stress cardiac magnetic resonance imaging at 1.5 T (N = 107; GG 56%, AG 43%, AA 31%, P = 0.042) and exercise testing (N = 87; -3.0 units in Duke Exercise Treadmill Score; -5.8 to -0.1; P = 0.045). Endothelin-1 related vascular mechanisms were assessed ex vivo using wire myography with endothelin A receptor (ETA) antagonists including zibotentan. Subjects with rs9349379-G allele had preserved peripheral small vessel reactivity to ET-1 with high affinity of ETA antagonists. Zibotentan reversed ET-1-induced vasoconstriction independently of G allele status.

CONCLUSION

We identify a novel genetic risk locus for CMD. These findings implicate ET-1 dysregulation and support the possibility of precision medicine using genetics to target oral ETA antagonist therapy in patients with microvascular angina.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT03193294.

Platelet/lymphocyte ratio for prediction of no-reflow phenomenon in ST-elevation myocardial infarction managed with primary percutaneous coronary intervention

Background

Coronary no-reflow phenomenon in ST-segment elevation myocardial infarction (STEMI) is associated with a poor clinical outcome. Although its pathophysiology is not fully understood, a deregulated systemic inflammatory response plays an important role. We aimed to explore the relationship between platelet\lymphocyte ratio (PLR) and no-reflow in patients with acute STEMI who were treated with a primary percutaneous coronary intervention (PPCI).

Methods

A total of 200 patients with STEMI undergoing PPCI were included in the study. Transthoracic echocardiographic examination was performed to assess left ventricular (LV) ejection fraction (EF) and wall motion score index. Blood samples were assayed for platelet and lymphocyte count before PPCI. No-reflow was defined as coronary blood flow thrombolysis in myocardial infarction grade ≤II.

Results

No-reflow was observed in 58 (29%) of STEMI patients following PPCI. PLR was significantly higher in hypertensive patients compared to normotensive patients (144.7±91.6 vs. 109.1±47.1, respectively, P<0.001) and in the no-reflow group compared to the normal reflow group (214±93 vs. 101.6±51.3, respectively, P<0.0001). Logistic regression analysis revealed that PLR (β: 0.485, 95% CI: -0.006-0.001, P<0.002) and LV EF (β: 0.272, 95% CI: 0.009-0.034, P<0.001) were independent predictors of no-reflow after PPCI.

Conclusion

Pre-procedural increase in PLR is predictive of the no-reflow phenomenon following PPCI in STEMI patients.

Relevance for Patients

No reflow phenomenon is an unfavorable complication following PPCI in patients with acute STEMI. High pre-procedural PLR is an independent predictor of reperfusion failure and helps to identify patients who require prophylactic treatment.

Increased plasma lipoprotein-associated phospholipase A2 levels are associated with coronary slow flow

OBJECTIVE

Coronary slow flow (CSF) is characterized by delayed opacification of distal epicardial coronary arteries without significant coronary stenosis. In addition, The changes of lipoprotein-associated phospholipase A2 (Lp-PLA₂) as a significant predictive factor for CSF remain controversial. The study aims to investigate the association between plasma Lp-PLA₂ and CSF.

METHODS

In this retrospective study, 170 consecutive patients who underwent coronary angiography were enrolled in Beijing Anzhen Hospital from January 2017 to September 2019, and were divided into CSF group and normal control groups. According to coronary blood flow rate measured by the thrombolysis in myocardial infarction frame count (TFC) method, CSF was defined as TFC > 27. Serum Lp-PLA₂ levels were measured in an enzyme-linked immunosorbent assay.

RESULTS

Lp-PLA₂ levels were higher in the CSF group than in the control group (288.6 ± 50.3 versus 141.9 ± 49.7, P < 0.001) and were significantly correlated with the mean coronary artery thrombolysis in myocardial infarction (TIMI) frame count (r = 0.790, P<0.001). Logistic regression analysis showed that high Lp-PLA₂ was independently associated with CSF after adjustment for conventional risk factors (OR = 1.040, CI = 1.022-1.059, P<0.001). Male sex (OR = 2.192, CI = 1.161-4.140, P = 0.016) and hypertension (OR = 1.965, CI = 1.034-3.736, P = 0.039) were also CSF risk factors. Receiver-operating characteristic curve (ROC) analysis showed that Lp-PLA₂ levels can predict CSF severity; the predictive power was higher than the other risk factors.

CONCLUSION

Our study demonstrated that patients with CSF had higher circulating levels of Lp-PLA₂ than normal controls. After adjustment for potential confounders, increased Lp-PLA₂ was independently associated with presence of CSF.

Could platelet distribution width predict coronary collateral development in stable coronary artery disease?

OBJECTIVE:

We hypothesized that hemogram parameters should be related to the development of coronary collateral vessels. For this purpose, we aimed to compare platelet distribution width (PDW) and PDW to platelet ratio (PPR) in subjects with stable coronary artery disease having adequate or inadequate coronary collateral development.

METHODS:

A total of 398 patients with stable angina pectoris undergoing coronary angiography were enrolled and divided on the basis of the development of coronary collateral (CCD) (inadequate CCD (n=267) and adequate CCD (n=131). Routine complete blood count and biochemical parameters were measured before coronary arteriography.

RESULTS:

Mean PDW and PPR values of inadequate and adequate CCD groups were 17.5% (10–23) and 12.4% (9.8–22) %, p<0.001, respectively. In multivariate analysis, age (p=0.012, 95% CI for OR: 0.958 (0.933–0.983) and PDW (p<0.001, 95% CI for OR: 1.432 (1.252–1.618) were found to be statistically significantly different inadequate CCD group compared to adequate CCD group. Receiver operating curve (ROC) analyses revealed that a PPR value greater than 0.057 had 76% sensitivity and 51% specificity and a PDW higher than 16.2% had 80% sensitivity and 66% specificity in predicting inadequate CCD.

CONCLUSION:

The present study suggests that PDW and PPR may be associated with the degree of collateral development in chronic stable coronary artery disease (CAD).

Early Assessment of Left Ventricular Function by Layer-Specific Strain and Its Relationship to Pulsatile Arterial Load in Patients with Coronary Slow Flow

Previous studies reported a controversial left ventricular (LV) function impairment and pathophysiology in patients with coronary slow flow (CSF). Greater arterial load has been shown to increase aortic impedance and endothelial shear stress, potentially affecting coronary anatomy and function. We investigated LV systolic function by a new layer-specific strain technology and assessed the association between pulsatile arterial load and contractility.A total of 70 patients with CSF and 50 controls with normal coronary angiography were included in the study. Layer-specific longitudinal and circumferential strains were assessed from endocardium, mid-myocardium, and epicardium (global longitudinal strain (GLS)-endo, GLS-mid, GLS-epi and GCS-endo, GCS-mid, GCS-epi) by two-dimensional speckle tracking imaging (2D-STI). Pulsatile arterial load was estimated by indexed arterial compliance (ACI). Layer-specific GLS showed a decreasing gradient from the endocardium to the epicardium in both the controls and CSF group. GLS-endo and GLS-mid in the CSF group were significantly lower than the control group (all P < 0.05). Layer-specific longitudinal strain showed a good correlation with the number of affected coronary arteries (all P < 0.05) and the mean thrombolysis in the myocardial infarction frame count (TFC) (all P < 0.05). ACI was lower in patients with CSF (P = 0.005), and ACI was correlated negatively with layer-specific GLS (all P < 0.05).Layer-specific evaluation of the LV provides an understanding of the layer-specific properties of the LV wall and the possible process of the LV impairment in patients with CSF. Greater pulsatile arterial load, as manifested by a lower ACI, is coupled with worse LV longitudinal function in patients with CSF.

Association of mean platelet volume and red blood cell distribution width with coronary collateral development in stable coronary artery disease

INTRODUCTION

The prognostic value of hematological indices in cardiovascular diseases and the association between these parameters and cardiovascular conditions have been established in the literature.

AIM

In this study, we aimed to investigate the relation of mean platelet volume (MPV), MPV to platelet ratio (MPR) and red cell distribution width (RDW) with degree of coronary collateral development (CCD) in stable coronary artery disease (CAD) subjects with established critical coronary artery stenosis.

MATERIAL AND METHODS

A total of 306 patients with stable angina pectoris undergoing coronary arteriography were enrolled and divided on the basis of the development of CCD into two groups: a group with adequate CCD (n = 214) and a group with impaired CCD (n = 92). Routine complete blood count and biochemical parameters were measured before coronary arteriography.

RESULTS

The MPV and MPR levels were significantly higher in the inadequate CCD group (10.5 ±1.8 fl vs. 8.7 ±1.9 fl, p < 0.001 and 0.06 ±0.08 vs. 0.05 ±0.07, p = 0.036). Patients with inadequate CCD had significantly higher RDW levels compared to patients with adequate CCD (15.5 ±1.7% vs. 15.0 ±1.9%, p = 0.01). MPV and RDW were significantly associated with Rentrop collateral grading (r = -0.523, p < 0.001 and r = -0.239, p < 0.001, respectively), whereas the association with MPR was not significant. An MPV value greater than 9.95 fl, determined with ROC curve analysis, had 71% sensitivity and 70% specificity in predicting inadequate CCD. An RDW greater than 14.3% has 71% sensitivity and 53% specificity in selecting patients with adequate CCD.

CONCLUSIONS

The present study suggests that MPV and MPR may be associated with the degree of collateral development in chronic stable CAD. However, the negative association of RDW with inadequate CCD, in combination with previous contradictory reports, raises a doubt about the possible value of RDW in stable CAD. Although these parameters may be affected by various conditions, a high MPV may lead clinicians to suspect possible inadequate collateral development in stable CAD patients.

T-Wave Indices and Atherosclerosis

Tpeak-Tend interval, the time difference between the peak and the end of the T-wave, reflects the degree of dispersion of repolarization. Its prolongation has been associated with higher risks of developing ventricular arrhythmias and sudden cardiac death in different pro-arrhythmic conditions such as Brugada and long QT syndromes. In this review, we will provide a comprehensive overview on how Tpeak-Tend is altered in different atherosclerotic conditions such as hypertension, stable coronary artery disease, acute coronary obstruction, and coronary slow flow as well as inflammatory diseases affecting the arterial tree. We will explore its relationship with arterial function and dysfunction, ventricular remodeling, and arrhythmic and mortality outcomes. The published literature shows that patients with coronary atherosclerosis, whether in the form of stable coronary artery disease, chronic total occlusion, slow flow, or acute coronary obstruction, have prolonged Tpeak-Tend intervals and Tpeak-Tend/QT ratios. These can be used to predict the occurrence of ventricular arrhythmias and sudden cardiac death. They also correlate with the extent and severity of arterial stenosis and structural remodeling of the ventricles as well as arterial function and dysfunction. Finally, they can be normalized following revascularization and may therefore be used as a surrogate measure of treatment success.

Effect of Coronary Slow Flow on Intrinsicoid Deflection of QRS Complex

Coronary slow flow is a rare, clinically important entity observed in acute coronary syndrome. The pathophysiological mechanism is not fully elucidated. We investigated patients with chest pain who had angiographic features consistent with the coronary slow flow. One hundred ten patients were included. Electrocardiography, echocardiography, and angiography results were retrospectively noted. The mean age was 56.4. Fifty-eight were male, and fifty-two were female. The control group consisted of patients with normal angiography. Patients had higher diastolic blood pressure, lower mean ejection fraction, higher average left ventricular end-diastolic diameter, and higher mean left atrial size than the control group (p=0.009, p=0.017, p=0.041, andp < 0.001, resp.). Patients had higher average V1 ID, V6 ID, P wave dispersion, TFC LAD, TFC Cx, TFC RCA, and TFC levels than the control group. A significant linear positive relationship was found between the V1 ID and the TFC LAD, TFC Cx, TFC RCA, and TFC; also between the V6 ID and the TFC LAD, TFC Cx, TFC RCA, and TFC. Angiographic and electrocardiographic features are suggestive and diagnostic for the coronary slow flow syndrome. Although when regarded as a benign condition, coronary slow flow should be diagnosed, followed up, and treated as many of laboratory features suggest ischemic events.

Evaluation of ghrelin levels and endothelial functions in patients with coronary slow flow phenomenon

BACKGROUND

Ghrelin has recently been reported to have beneficial effects on cardiac contractile functions and coronary blood flow. The main purpose of this study was to investigate the role of ghrelin in the pathogenesis of coronary slow flow (CSF) together with endothelial functions.

METHODS

Twenty-five patients having normal coronary arteries with CSF and 25 controls with normal coronary flow were included into the study. The quantitative measurement of coronary blood flow was performed for each coronary artery using the thrombolysis in myocardial infarction (TIMI) frame count (TFC) method. Ghrelin levels were measured using the enzyme-linked immunosorbent assay method from venous blood samples. Endothelial functions were evaluated from the brachial artery with the flow-mediated dilation (FMD) and nitrate-related dilation methods.

RESULTS

There was a significant difference in terms of mean TFC values between the control and CSF groups (p < 0.001 for all coronary arteries). The mean FMD percentage among patients with CSF was lower than that of the control group (5.9 ± 0.8 vs. 10.7% ± 1.1%; p < 0.001). A moderate negative correlation was observed between the FMD percentages and the TFCs. There was no relationship between the TFC and ghrelin levels.

CONCLUSION

Plasma ghrelin levels seem to be uninfluential while impaired endothelial functions play an important role in the etiopathogenesis of CSF.

Endothelial nitric oxide synthase gene polymorphisms in patients with slow coronary flow

Background and aims

The aim of this study was to explore potential associations of the intron 4 variable number of tandem repeats (VNTR) and E298A polymorphisms of the endothelial nitric oxide synthase (eNOS) gene with slow coronary flow (SCF). The association between plasma nitrate and nitrite (NO _x ) concentrations and eNOS gene polymorphisms was also assessed.

Materials and methods

The intron 4 VNTR and E298A polymorphisms of the eNOS gene were evaluated in the isolated DNA blood samples obtained from the SCF patient group (n = 30) and healthy group consisted of age- and sex-matched controls (n = 61).

Results

Plasma NO _x level was significantly lower in patients with SCF than in controls. In addition, patients with SCF have significantly lower nitric oxide levels than control subjects within each genotype variants. The allele and genotyped frequencies of the eNOS intron 4 VNTR and E298A polymorphisms were similar between patients with SCF and the controls. Plasma NO _x concentrations with respect to the relevant genotypes were found insignificant.

Discussion and conclusion

Plasma NO _x is lower in patients with SCF than in healthy subjects. Our findings may suggest the lack of association between intron 4 VNTR and E298A polymorphisms of the eNOS gene and SCF.

Transcriptional Activity of Gene Encoding Subunits R1 and R2 of Interferon Gamma Receptor in Peripheral Blood Mononuclear Cells in Patients with Slow Coronary Flow

Background

Slow coronary flow (SCF) is a coronary artery disorder characterized with delayed opacification of epicardial coronary arteries without obstructive coronary disease. The pathophysiological mechanisms of SCF remain unclear. One of the possible mechanisms that may participate in the pathology of SCF is endothelial dysfunction related to the inflammatory process. Interferon gamma (IFN-γ) is an inflammatory cytokine that acts through its specific receptor composed of two subunits, IFN-γR1 and IFN-γR2. Transcriptional activity of the gene encoding these subunits influences IFN-γ activity. This study aimed to investigate the gene expression of IFN-γ receptor subunits in peripheral blood mononuclear cells (PBMC) from patients with SCF.

Methods

The study was performed with 30 patients (22 male/8 female) aged 35–76 (52.8±11.7 years) with SCF and 15 sex- (11 male/4 female), Body Max Index (BMI)- and age-matched (54.73±9.42 years) healthy subjects. Total mRNA was extracted from PBMC and was determined by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). The relative expression values (2^-ΔΔCt) between control and case groups were determined and the Mann-Whitney U test was used for statistical analysis.

Results

There was a significant increase in the gene expression of IFN-γR1 in PBMC from SCF patients vs. controls (P< 0.0001); but the differences in IFN-γR2 gene expression were statistically insignificant between patient and control groups (P= 0.853).

Conclusions

It can be concluded that IFN-γ gene expression may influence the function of microvasculature and thereby contribute to the pathophysiology of SCF.

Is dipyridamole useful in improving left ventricular systolic and diastolic function in patients with coronary slow flow?

BACKGROUND

Coronary slow flow (CSF) is an angiographic finding characterized by delayed opacification of epicardial coronary arteries without obstructive coronary disease. Previous studies have shown greater impairment of left ventricular (LV) systolic and diastolic function in patients with CSF. We aimed to examine the effect of dipyridamole on these functions.

METHODS

Our study included 40 patients with CSF and 40 subjects with normal coronary arteries. Conventional echocardiography Doppler imaging (CDI) and tissue Doppler echocardiography imaging (TDI) were used to evaluate LV systolic and diastolic function before and 2 months after treatment with dipyridamole.

RESULTS

Using CDI, we observed that early diastolic velocity (E) was significantly lower in patients with CSF, while late diastolic velocity (A), E/A ratio, isovolumic relaxation time, and myocardial performance index (MPI) were significantly higher in CSF patients compared with controls. Similarly, while early myocardial velocity (Em) was significantly lower, late myocardial velocity (Am), Em/Am ratio, isovolumic relaxation time (IRT), and MPI were significantly higher in CSF patients according to TDI measurements. Although there was no significant improvement in conventional Doppler parameters, there was significant normalization in tissue Doppler parameters after treatment with dipyridamole.

CONCLUSION

Left ventricular systolic and diastolic function may be negatively affected by CSF. Dipyridamole may improve these functions, especially at the tissue level.

The relation of platelet-lymphocyte ratio and coronary collateral circulation in patients with non-ST segment elevation myocardial infarction

Introduction

Recently, platelet-to-lymphocyte ratio (PLR) has emerged as a significant inflammatory marker and a novel predictor of major adverse consequences in cardiovascular disease.

Aim

In this study, we aimed to explore the relationship between PLR and coronary collateral circulation (CCC) in patients with non-ST elevation myocardial infarction (NSTEMI).

Material and methods

Clinical and laboratory data of 386 patients who underwent coronary angiography were evaluated retrospectively. The patients were classified into 2 groups as follows: poor CCC (group 1: Rentrop grades 0–1) and good CCC (group 2: Rentrop grades 2–3). The PLR was calculated from the complete blood count.

Results

The PLR values of the patients with poor CCC were significantly higher than those of patients with good CCC (153.9 ±26.6 vs. 129.8 ±23.5, p < 0.001). In the multiple logistic regression tests, PLR (odds ratio: 1.51, 95% confidence interval: 1.27–1.74; p < 0.001) and hs-CRP (odds ratio: 1.56, 95% CI: 1.03–2.11; p < 0.001) were found to be independent predictors of poor CCC. The receiver operating characteristic (ROC) curve analysis yielded a cutoff value of 140.5 for PLR to predict poor CCC with 79% sensitivity and 71% specificity, with the area under the ROC curve being 0.792 (95% CI: 0.721–0.864).

Conclusions

Our study revealed that high PLR is independently associated with poor coronary collateral circulation in patients with NSTEMI.

Predictive Value of Neutrophil Lymphocyte Ratio and Platelet Lymphocyte Ratio in Patients with Coronary Slow Flow

BACKGROUND

Increased microvascular resistance due to chronic inflammation is assumed to be one of the mechanisms associated with coronary slow flow (CSF). Previous studies have shown that the platelet-to-lymphocyte ratio (PLR) and the neutrophil-lymphocyte ratio (NLR) are markers of inflammation for various diseases. In this study we aimed to evaluate the relationship between CSF and PLR-NLR.

METHODS

Seventy-eight patients with CSF and 50 patients with normal coronary flow were enrolled into this study. The study subjects underwent medical examination and testing, after which their platelet-to-lymphocyte ratios and NLR values were calculated. An independent observer measured the coronary flow rate by Thrombolysis in Myocardial Infarction Frame Count (TFC) method. The platelet-to-lymphocyte ratio and NLR values were compared between the groups and correlation analysis was performed to explore the relationship between mean TFC with PLR and NLR.

RESULTS

Platelet-to-lymphocyte ratio and NLR values were significantly higher in patients with CSF (p < 0.001). There was a positive significant correlation between TFC with NLR and PLR (Spearman's Rho: 0.59, p < 0.001 and Spearman's Rho: 0.30, p = 0.001, respectively). Multivariate logistic regression analysis revealed that NLR is the one independent predictor for CSF.

CONCLUSIONS

This study demonstrated an association between CSF and PLR-NLR. Although the exact mechanism could not be explained, our findings support the possible role of inflammation in CSF physiopathology.

The Relationship Between Serum Endocan Levels With the Presence of Slow Coronary Flow: A Cross-Sectional Study

BACKGROUND

The aim of this study was to investigate the relationship between endocan levels with the presence of slow coronary flow (SCF).

METHODS

In this cross-sectional study, a total of 88 patients, who admitted to our hospital, were included in this study. Of these, 53 patients with SCF and 35 patients with normal coronary flow were included in the final analysis. Coronary flow rates of all patients were determined by the Timi Frame Count (TFC) method.

RESULTS

In correlation analysis, endocan levels revealed a significantly positive correlation with high sensitive C-reactive protein and corrected TFC. In multivariate logistic regression analysis, the endocan levels were found as independently associated with the presence of SCF. Finally, using a cutoff level of 2.3, endocan level predicted the presence of SCF with a sensitivity of 77.2% and specificity of 75.2%.

CONCLUSION

In conclusion, our study showed that higher endocan levels were significantly and independently related to the presence of SCF.

Echo-tracking technology assessment of carotid artery stiffness in patients with coronary slow flow

Coronary slow flow (CSF) in coronary angiography (CAG) is a well-recognized clinical entity. Previous studies have suggested that microvascular abnormalities and endothelial dysfunction are responsible for CSF. Accordingly, we hypothesized that the CSF phenomenon is a form of atherosclerosis including both small vessels and epicardial coronary arteries. The echo-tracking (ET) technique is a non-invasive detection method for early prediction of arterial atherosclerosis. Therefore, we investigated carotid elasticity with the ET technique in patients with CSF. Fifty patients with CSF and 50 patients with normal coronary artery blood flow, as determined by CAG, with a similar distribution of risk factors were recruited. The stiffness parameter (β), pressure-strain elastic modulus (Ep), arterial compliance (AC), augmentation index (AIx) and local pulse-wave velocity (PWV) were determined at the level of the bilateral common carotid artery (CCA) with using the ET technique. Levels of serum high-sensitivity C-reactive protein (hs-HSCRP) were determined for the two groups. β, Ep and PWV were significantly higher in the CSF group than in the control group (β: 11.4 ± 3.76 vs. 9.22 ± 3.28, p < 0.01; Ep: 153.44 ± 47.85 vs. 126.40 ± 43.32, p < 0.01; PWV: 7.26 ± 1.10 vs. 6.55 ± 1.02, p < 0.01), but AC was lower in the CSF group than in the control group (0.62 ± 0.20 vs. 0.74 ± 0.24, p < 0.01). The elasticity parameters of the bilateral common carotid artery did not significantly differ. The level of hs-HSCRP was correlated positively with β (r = 0.306, p = 0.015), Ep (r = 0.358, p = 0.005) and PWV (r = 0.306, p = 0.015), but negatively with AC (r = -0.236, p = 0.049). In conclusion, the ET technique is a simple practical method for evaluating carotid artery elasticity, and there is a significant correlation between carotid artery stiffness and level of hs-HSCRP in patients with CSF.

Endothelial nitric oxide synthase levels and their response to exercise in patients with slow coronary flow

Background

Endothelial dysfunction plays a key role in the aetiopathogenesis of slow coronary flow (SCF) even if there is no obstructive epicardial lesion. Reduced plasma levels of endothelial nitric oxide synthase (eNOS) are an important indicator of endothelial dysfunction. We aimed to determine plasma levels of eNOS and their relationship with exercise in patients with SCF.

Methods

Twenty-two patients with SCF in at least one coronary artery and 17 healthy individuals were included in this study. The TIMI frame count method was used to determine SCF. Plasma levels of eNOS before and after effort were determined in the patient and control groups.

Results

Basal eNOS levels in the patient group were lower than in the control group (p = 0.040), and plasma eNOS levels after exercise decreased more significantly in the patient group compared to the control group (p = 0.002). Median decreases of eNOS in response to exercise were higher in the SCF group than in the control group (p < 0.001), and the decrease observed in the control group was not statistically significant (p = 0.35). There were significantly negative correlations between TIMI frame count and plasma levels of eNOS at baseline and after exercise (r = –0.51, p = 0.015, r = –0.58, p = 0.005, respectively). Moreover, there was also a positive correlation between the rate–pressure product and plasma levels of eNOS after exercise in patients with SCF (r = 0.494, p = 0.019).

Conclusion

Our findings indicate an important pathophysiological relationship between the severity of SCF in which endothelial dysfunction plays a role in its pathogenesis and the level of circulating plasma levels of eNOS.

Coronary slow flow: Benign or ominous?

Objective:

Coronary slow flow phenomenon has been arbitrarily defined as delayed coronary blood flow in the absence of obstructive coronary artery disease. The present study sought to investigate the clinical features, natural history, and outcomes of affected patients.

Methods:

In this prospective cross-sectional study, 217 consecutive patients who had undergone coronary angiography and showed features of coronary slow flow phenomenon were evaluated for demographic and coronary risk factor profile, as well as clinical outcomes, at baseline and following treatment.

Results:

The study population consisted of 165 (76%) males and 52 (24%) females. The mean age of patients was 52.6±10 years. Mean ejection fraction was 48.2±5.4, 39.3% had diabetes, 43.3% had hypertension, 49.8% was a cigarette smoker, 41.9% had dyslipidemia, and 15% had a familial history of cardiac disease. Forty-nine percent was detected to have abnormal hsCRP levels. The most prevalent presenting complaint was atypical chest pain. Fifty-four percent of patients had slow blood flow in all three vessels. Thirty-six people had undergone repeat coronary angiography in a follow-up period of 5-7 years due to persisting or worsening clinical symptoms, of whom 6 (16.6%) showed significant coronary artery stenosis. Eight (22.2%) had mild CAD, and the rest still showed coronary slow flow without significant stenosis. The most common complaint during follow-up and after initiation of medical therapy was nonanginal chest pain.

Conclusion:

Patients with coronary slow flow phenomenon are predisposed to atherosclerosis and obstructive coronary artery disease. Therefore, this pathology should not be considered as a totally benign condition. Primary and secondary cardiovasculature preventive measures should be constituted and seem worthwhile in this patient population.

Relationship between platelet-to-lymphocyte ratio and coronary slow flow

OBJECTIVE

The coronary slow flow phenomenon (CSFP), which is characterized by delayed distal vessel opacification in the absence of significant epicardial coronary disease, is an angiographic finding. The aim of this study is to investigate the association between platelet-to-lymphocyte ratio (PLR) and coronary blood flow rate.

METHODS

This is a retrospective observational study. It was based on two medical centers. A total of 197 patients undergoing coronary angiography were included in the study, 95 of whom were patients with coronary slow flow without stenosis in coronary angiography and 102 of whom had normal coronary arteries and normal flow.

RESULTS

The PLR was higher in the coronary slow flow group compared with the control groups (p=0.001). In the correlation analysis, PLR showed a significant correlation with left anterior descending (LAD) artery thrombolysis in myocardial infarction (TIMI) frame count. After multiple logistic regression, high levels of PLR were independently associated with coronary slow flow, together with hemoglobin.

CONCLUSION

PLR was higher in patients with CSFP, and we also showed that PLR was significantly and independently associated with CSFP.

The coronary slow flow phenomenon: characteristics, mechanisms and implications

The coronary slow flow phenomenon (CSFP) is an important, angiographic entity characterized by delayed progression of the injected contrast medium through the coronary tree. It is a frequent finding, typically observed in patients presenting with acute coronary syndromes. Although it is well known to interventional cardiologists for approximately four decades, the pathogenic mechanisms remain unclear. The clinical implications are significant, with over 80% of patients experiencing recurrent chest pain, resulting in considerable impairment in quality of life. This article will address in detail the characteristics, possible mechanisms, and clinical implications of this entity to provide further insight into its clinical significance and management strategies.

Carotid intima-media thickness in patients with slow coronary flow and its association with neutrophil-to-lymphocyte ratio: a preliminary report

BACKGROUND

The slow coronary flow (SCF) is characterized by angiographically normal or near-normal coronary arteries with delayed progression of the contrast agent into distal vasculature. We aimed to investigate neutrophil-to-lymphocyte (N/L) ratio and the carotid intima-media thickness (CIMT) value in patients with SCF compared to patients with newly diagnosed coronary artery disease (CAD) and normal patients.

MATERIALS AND METHODS

We enrolled 60 consecutive patients with SCF, 68 patients with CAD, and 72 normal patients. The association between thrombolysis in myocardial infarction frame count, CIMT, and N/L ratio and other clinical and laboratory parameters were evaluated.

RESULTS

The N/L ratio was significantly higher not only in patients with SCF but also in patients with CAD, compared to those of controls. The N/L ratio was positively and moderately correlated with CIMT in the whole study population.

CONCLUSIONS

The NL ratio is significantly associated with reduced coronary blood flow, and elevated N/L ratio might be an independent predictor for the presence of SCF.

Evaluation of microvascular angina with TIMI frame count using nitroprusside induced hyperemia

TIMI frame count (TFC) provides a quantitative index of coronary microvascular dysfunction. Previous studies suggested the degree of frame count reserve (FCR) and slow coronary flow (SCF) correlated with microvascular dysfunction. We investigated the clinical implication of FCR and SCF for the evaluation of microvascular angina (MA). We included consecutive 77 patients with the complaint of chest pain, who subsequently had normal coronary angiography. TFC was obtained from left anterior descending artery. Intracoronary nitroprusside (15 μg) was infused to induce hyperemia, and repeat angiogram was performed after 30s. FCR was calculated by dividing basal TFC by hyperemic TFC. SCF was defined as being present when TFC was more than 28. All patients underwent a treadmill test without medication after angiography. After the treadmill test, patients were divided into a MA group (40 patients) and a control group (37 patients). FCR was similar in both groups (2.0±1.0 and 2.1±0.9, MA and control group, respectively). However, hyperemic TFC induced by nitroprusside was significantly higher in the MA group (10.9±4.7) than in the control group (9.0±3.5, p<0.05). Patients who showed SCF had a significantly greater incidence of MA (78.5%; 11/14 patients) than that with normal coronary flow (46.0%; 29/63 patients, p<0.05). The higher hyperemic TFC and presence of SCF were found to have a diagnostic value for MA.

The relationship between coronary slow flow phenomenon and coronary calcium score

AIM

Coronary slow flow phenomenon (CSFP) is an angiographic finding characterized by delayed distal vessel opacification without any significant epicardial coronary artery disease. Several studies have suggested that CSFP might be a form of atherosclerosis. The present study was aimed to investigate the relationship between CSFP and coronary artery calcification, which is one of the clear-cut indicators of coronary atherosclerotic plaque, by using computerized tomography.

METHOD

Fifty-five patients were included in the study. The coronary arteries of all patients were shown by angiography to be normal. Coronary slow flow (CSF) patterns were evaluated by the thrombolysis in myocardial infarction frame count (TFC) method. Patients with normal coronary arteries and CSF were allocated into the CSF group, and patients with normal coronary arteries and normal coronary flow were allocated into the control group. Coronary artery calcium (CAC) score was measured in 28 patients with CSF and in 27 controls by 64-slice computerized tomography.

RESULTS

The CSF and control groups were similar with respect to age, gender, smoking status, presence of hypertension and diabetes mellitus, cholesterol profiles, and Framingham risk scores (p>0.05). The CSF and control groups were not significantly different with respect to CAC score (p>0.05). Sub-group analysis of cardiac risk factors in patients with or without coronary artery calcification revealed that advanced age and low high density lipoprotein (HDL) levels were significantly associated with coronary artery calcification. There wasn't any relationship between coronary slow flow and cardiac risk factors or coronary calcium scores.

CONCLUSION

In the present study, no association was found between the CSFP and calcified atherosclerosis. Additionally, it was demonstrated that, among the cardiac risk factors, advanced age and low HDL levels were associated with coronary artery calcification.

Coronary slow flow phenomenon: a local or systemic disease?

Coronary slow flow phenomenon (CSFP) is an important, angiographic entity characterized by delayed progression of the contrast medium injected into the coronary tree. Since definition of this phenomenon in 1972, there has not been any clear-cut etiology. Original data often focused on histological or pathological changes in coronary artery itself. It was confirmed that small vessel structural defect as well as an underlying residual microvascular resistance abnormality coexists in the coronary microcirculation. Early atherosclerosis was also detected in epicardial coronary arteries by intravascular ultrasound (IVUS). Taken together, it can be suggested that a combination of morphological and functional abnormalities in small vessels and epicardial coronary arteries contributes to the pathogenesis of CSFP. CSFP may be defined as a local disease confined to coronary arteries. However, another feature of CSFP is its frequent occurrence in association with more widespread vascular abnormalities. Reduced endothelial function is implicated in CSFP as measured by flow-mediated dilatation (FMD) of the brachial artery, suggesting that endothelial dysfunction appears to be a generalized process affecting both coronary and peripheral vasculature. In addition, several studies have now demonstrated that carotid intima-media thickness (IMT) is significantly increased in patients with CSFP and there was a significant correlation between coronary intima-media thickness and carotid IMT. Therefore, we hypothesize that CSFP is not an isolated finding but may be part of a systemic vascular disturbance. CSFP is not an infrequently detected finding typically observed in patients presenting with an acute coronary syndrome, usually unstable angina. The subsequent clinical course is characterized by high frequency of relapsing chest pain resulting in considerable impairment in quality of life. Accordingly, further experimental investigations and clinical studies are warranted to shed light into the pathogenesis as well as therapeutics of CSFP.

Documentation of impaired coronary blood flow in chronic obstructive pulmonary disease patients

BACKGROUND

In the current study, the effects of moderate to severe chronic obstructive pulmonary disease (COPD) on coronary blood flow in patients with angiographically proven normal coronary arteries was evaluated.

METHODS AND RESULTS

A total of 85 patients with moderate to severe COPD and 39 age- and sex-matched control partcipants, who underwent diagnostic coronary angiography and found to have normal epicardial coronary angiogram constituted the COPD and control groups, respectively. The 2 groups were compared for Thrombolysis In Myocardial Infarction (TIMI) frame counts in each major coronary artery. The TIMI frame count of the COPD group was significantly higher than that of control group for all 3 major individual coronary arteries: left anterior descending (corrected), 37+/-13 vs 20+/-4; right coronary artery, 32+/-14 vs 21+/-4; and left circumflex artery, 34+/-12 vs 20+/-5, (P<0.001 for all). In addition, TIMI frame counts in individual coronary arteries were found to be positively correlated with forced expiratory volume 1 s percent, serum high sensitive C-reactive protein and fibrinogen concentrations, in the COPD group.

CONCLUSIONS

Our findings suggest that an increased slow coronary flow might be a manifestation of harmful effects of COPD on the coronary circulation, regardless of the underlying mechanism.

Endothelial dysfunction in patients with noncomplicated and complicated hypertension

Endothelial dysfunction plays an important role in the pathogenesis of hypertension. Other risk factors of atherosclerosis also affect its development. The aim of the study was to assess nitric oxide metabolites concentration (nitrites and nitrates No(x)) and endothelin (ET-1) in plasma and cyclic 3,5-guanosine monophosphate (cGMP) in 24 h-urine collection in patients with noncomplicated hypertension without risk factors of atherosclerosis and in hypertensive patients with coronary artery disease (CAD). Sixty-eight subjects were included in the study (44 men, 24 women), aged 47 +/- 76 years, allotted into four groups: I - controls (18 clinically healthy subjects); II - 12 subjects with hypertension without risk factors of atherosclerosis; III - 16 subjects with hypertension and risk factors of atherosclerosis; and IV - 22 subjects with hypertension and CAD. Plasma NO(x) concentration was determined using the Greiss method, plasma ET-1 by ELISA, and urine cGMP using the immunoenzymatic method. Plasma NO(x) concentration was 14.00 +/- 6.88 micromol/L in group I, in group II - 18.62 +/- 5.84 micromol, in group III - 9.96 +/- 4.72 micromol/L, and in group IV - 8.78 +/- 3.72 micromol/L. Statistically significant differences were between groups I and III (p < 0.05) and I and IV (p < 0.04) and groups II and III (p < 0.01) and II and IV (p < 0.01). The concentration of cGMP in 24 h urine collection was in group I - 40 +/- 24 pmol/L; in group II - 54 +/- 41 pmol/L; in group III - 38 +/- 32 pmol/L; and in group IV - 42 +/- 36 pmol/L. There were no significant differences between the groups. Plasma ET-1 concentration was 3.86 +/- 0.52 pg/mL in group I, in group II - 4.05 +/- 0.71 pg/mL, in group III - 4.22 +/- 0.79 pg/mL and in group IV - 4.38 +/- 0.75 pg/mL. Statistically significant differences were between group I and III (p < 0.05), I and IV (p < 0.03), and between group II and IV (p < 0.04). Endothelial dysfunction was not found in hypertensive patients without a family history of cardiovascular diseases and without other risk factors of atherosclerosis. Deterioration of endothelial function was observed in patients with hypertension with risk factors of atherosclerosis. It was most pronounced in those with CAD.