Significant Epicardial Coronary Artery Stenosis Research Articles

Ten questions about myocardial infarction with non-obstructed coronary arteries

The term "MINOCA" refers to myocardial infarction with non-obstructed coronary arteries and has been used to define acute myocardial infarction with no angiographic evidence of significant epicardial coronary artery stenosis. Patients with MINOCA represent a rather heterogeneous group of acute coronary syndrome, and this may account for the wide variation in the incidence of MINOCA in different studies. Several pathogenic mechanisms have been suggested to underlie MINOCA, but the condition continues to represent a diagnostic and therapeutic challenge for the cardiologist. Therefore, an adequate diagnostic assessment, carefully characterizing the pathogenic mechanisms, and a selection of more targeted treatments are needed to improve clinical outcomes. In this focused review, we will try to provide answers to the most common questions on the causes, diagnosis, treatment, and outcomes of MINOCA.

Prognostic Implications of Microvascular Resistance Reserve in Symptomatic Patients With Intermediate Coronary Stenosis

BackgroundMicrovascular resistance reserve (MRR) is a novel index reflecting coronary microcirculatory function, irrespective of epicardial coronary artery stenosis. There is limited evidence regarding whether MRR can be an independent prognostic tool in patients with stable ischemic heart disease (IHD). ObjectivesThe aim of this study was to evaluate clinical outcomes according to MRR in patients with stable IHD accompanied with or without significant epicardial coronary artery stenosis. MethodsThe present study included 547 consecutive patients undergoing systematic echocardiographic and invasive physiological assessment for suspected stable IHD. Significant epicardial coronary artery stenosis was defined as fractional flow reserve (FFR) ≤0.80. Coronary microvascular dysfunction (CMD) was defined as MRR ≤3.0. The primary outcome was major adverse cardiovascular events (MACE), a composite of cardiovascular death, myocardial infarction, repeat revascularization, and admission for heart failure. ResultsAmong the study group, 172 patients (31.4%) had FFR ≤0.80, and 200 patients (36.6%) had CMD defined by MRR ≤3.0. MRR showed no significant correlation with FFR (R = −0.031; P = 0.469), but it was significantly correlated with the index of microcirculatory resistance (R = −0.353; P < 0.001), N-terminal pro–B-type natriuretic peptide (R = −0.296; P < 0.001), left ventricular filling pressure (E/e′ ratio) (R = −0.224; P < 0.001), and diastolic dysfunction grade (P < 0.001). During a median follow-up period of 3.3 years (Q1-Q3: 2.0-4.5 years), MRR was significantly associated with MACE risk (HR: 1.23 per 1-U decrease; 95% CI: 1.12-1.36; P < 0.001). CMD defined by MRR ≤3.0 was associated with an increased MACE risk for both FFR >0.80 (41.0% vs 26.0%; adjusted HR: 1.59; 95% CI: 1.07-2.35; P = 0.021) and FFR ≤0.80 (34.7% vs 14.8%; adjusted HR: 2.32; 95% CI: 1.12-4.82; P = 0.024). ConclusionsDecreased MRR was associated with the presence of cardiac diastolic dysfunction as well as increased left ventricular filling pressure. The presence of CMD defined by MRR was independently associated with the risk for a composite of cardiovascular death, myocardial infarction, repeat revascularization, and admission for heart failure in patients with stable IHD, irrespective of significant epicardial coronary artery stenosis. (Prognostic Impact of Cardiac Diastolic Function and Coronary Microvascular Function [DIAST-CMD]; NCT05058833)

Rational and design of ST-segment elevation not associated with acute cardiac necrosis (LESTONNAC). A prospective registry for validation of a deep learning system assisted by artificial intelligence

BackgroundPatients with chest pain and persistent ST segment elevation (STE) may not have acute coronary occlusions or serum troponin curves suggestive of acute necrosis. Our objective is the validation and cost-effectiveness analysis of a diagnostic model assisted by artificial intelligence (AI). MethodsProspective multicenter registry in two groups of patients with STE: I) coronary arteries without significant lesions and without serum troponin curve suggestive of acute necrosis, II) myocardial infarction with acute coronary occlusion. The inclusion criteria are the following: 1) age ≥ 18 years, 2) chest pain or symptoms suggestive of myocardial ischemia, 3) STE at point J in two contiguous leads ≥0.1 mV, in V2 and V3 ≥ 0,2 mV and 4) signature of informed consent. The exclusion criteria are the following: 1) left bundle branch block, 2) acute cardiac necrosis in the absence of significant epicardial coronary artery stenosis, 3) STE ≤ 0.1 mV with pathologic Q wave, 4) severe anemia (hemoglobin <8.0 g/dl). For each patient without acute cardiac necrosis, the next patient from that center of the same sex and similar age (± 5 years) with myocardial infarction and acute coronary occlusion will be included. A manual centralized electrocardiographic analysis and another by deep learning AI will be performed. ConclusionsThe results of the study will provide new information for the stratification of patients with STE. Our hypothesis is that an AI analysis of the surface electrocardiogram allows a better distinction of patients with STE due to acute myocardial ischemia, from those with another etiology.

Role of Fibroblast Growth Factor-23 in Coronary Slow Flow Phenomenon Pathogenesis

The phenomenon of angina chest pain without significant epicardial coronary artery stenosis, but accompanied by a slowdown in coronary blood flow is often found in patients with symptoms of acute coronary syndrome who undergoing invasive coronary angiography. This phenomenon of slow coronary blood flow is then called the coronary slow flow phenomenon (CSFP). The pathogenesis mechanism of CSFP remains unclear. The pathogenesis of CSFP is thought to be multifactorial. Endothelial dysfunction, small vessel disease, inflammation, renin system angiotensin aldosterone, atherosclerosis are thought to be involved in the pathogenesis of CSFP. Cardiovascular disease incidence and death were associated with elevated levels of Fibroblast growth factor-23 (FGF-23). High levels of FGF-23 can lead to formation of blood vessel calcification, left ventricular hypertrophy, arterial stiffness, endothelial dysfunction, increased inflammatory markers and elevated levels of angiotensin II. It is suspected that FGF-23 has a role in this event other than as a regulator of bone and mineral metabolism. This literature review aims to determine the relationship between fibroblast growth factor-23 and the pathophysiology of CSFP. Based on the broad role of FGF-23, it is possible that FGF-23 is involved in the pathogenesis of CSFP.

Percutaneous Coronary Revascularization in Patients With Single Coronary Artery

IntroductionSingle coronary artery (SCA) is a rare congenital coronary anomaly. Its incidence in various angiographic series is from 0.024% to 0.066%. Percutaneous coronary intervention (PCI) of coronary artery disease (CAD) in these patients is technically challenging. MethodsWe retrospective analyzed the cardiac catheterization procedures of last 15 years and found 12 cases of SCA (incidence 0.084%). To determine the course of anomalous coronaries, angiographic “dot and eye” method and computed tomography (CT) were used. The course of the SCA was classified as per the modified Lipton criteria. PCI was performed as per the standard protocol for a significant epicardial coronary artery stenosis. ResultsOut of total 12 patients of SCA, 9 patients had PCI of significant CAD. The mean age of 9 PCI patients was 63.8 ± 8.2 years (5 males, 4 females). The origin of the SCA was from the right sinus of Valsalva in 6 cases and from left sinus of Valsalva in 3 cases. Eleven successful PCI procedures were performed, which included PCI of left main, coronary bifurcation lesion, chronic total occlusion, and multi-vessel disease. Four patients had intravascular imaging and 3 patients had rotablation of calcified lesions. ConclusionPCI of SCA is technically challenging, which requires considerable expertise and experience. An appropriate selection of hardware along with technical expertise can make the procedure simpler with optimal end results.

(Epicardial and microvascular) angina or atypical chest pain: differential diagnoses with cardiovascular magnetic resonance.

Angina pectoris is a chest discomfort caused by myocardial ischaemia, and it is classified as ‘typical’ or ‘atypical’ if specific features are present. Unfortunately, there is a heterogeneous list of cardiac diseases characterized by this symptom as onset sign. Mostly, angina is due to significant epicardial coronary artery stenosis, which causes inadequate oxygen supply increase after raised myocardial oxygen demand. In the absence of significant epicardial stenoses, another potential cause of angina is microvascular dysfunction, related to inadequate response of resistance coronary vessels to vasodilator stimuli. The unique capability of cardiovascular magnetic resonance (CMR) in providing extremely detailed morphological and functional information, along with precise stress perfusion defects and wall motion abnormalities depiction, translates it into the test with one of the best diagnostic performance and prognostic stratification among non-invasive cardiac imaging modality. Moreover, CMR is also extremely accurate in detecting non-ischaemic cardiac causes of chest pain (such as myocardial and pericardial inflammation, or stress-related cardiomyopathy), and is very useful in helping physicians to correctly approach patients affected by chest pain.

The association between serum angiogenin and osteopontin levels and coronary collateral circulation in patients with chronic total occlusion.

Objective:A well-developed coronary collateral circulation lowers both in-hospital and long-term morbidity and mortality limiting the infarct. Angiogenin (AGN) and osteopontin (OPN) are known to be potent inducers of angiogenesis. The aim of the present study was to investigate the relationship between serum ANG and OPN levels and collateral filling grade in subjects with stable coronary artery disease (SCAD).Methods:A total of 122 age- and gender-matched consecutive patients who were found to have total occlusion (n=70) and no significant stenosis in epicardial coronary arteries (n=52) who underwent coronary angiography due to SCAD between January 2015 and July 2017 were included in the study. AGN and OPN levels were measured using enzyme-linked immunosorbent assay. Coronary collateral circulation was graded using Rentrop’s classification of collateral filling.Results:A total of 52 patients (61.60±11.78 years, 61.5% male) without significant epicardial coronary artery stenosis and 70 patients (62.87±8.24 years, 65.7% male) with totally occluded coronary arteries were included in the study. Subjects with total occlusion had significantly higher levels of AGN [122.00 (79.00–623.00) pg/mL vs. 98.00 (18.00–160.00) pg/mL, p<0.001] and OPN [1863.50 (125.00–6500.00) pg/mL vs. 451.00 (112.00–1850.00) pg/mL, p<0.001] than those without significant stenosis. In addition, AGN [127.00 (87.00–623.00) pg/mL vs. 110.00 (79.00–188.00) pg/mL, p=0.011] and OPN [2681.00 (126.00–6500.00) pg/mL vs. 649.00 (125.00–4255.00) pg/mL, p=0.001] levels were significantly higher in patients with better developed collaterals. Serum AGN and OPN levels were found to be significantly associated with coronary collateral development.Conclusion:AGN and OPN are associated with better developed coronary collateral circulation and may have therapeutic implications for the promotion of coronary collateral development.

Is the longitudinal deformation of the left ventricle affected by vitamin D deficiency in nondiabetics? A 2D speckle-tracking echocardiographic study.

Vitamin D deficiency with its high global prevalence is associated with some pathological changes in the myocardium. The aim of our study was to assess the longitudinal deformation of the left ventricular (LV) myocardium in subjects with vitamin D deficiency. This cross-sectional study recruited 98 consecutive nondiabetic subjects (45 subjects with vitamin D deficiency and 53 subjects without vitamin D deficiency) without significant epicardial coronary artery stenosis. The longitudinal subendocardial deformation indices of the LV myocardium were evaluated with 2D speckle-tracking echocardiography. The end-systolic strain, the systolic strain rate, and the early and late diastolic strain rates were not statistically significantly different between the subjects with and without vitamin D deficiency. The global longitudinal subendocardial deformations of the LV, including the systolic strain rate and the systolic and diastolic strain rates, as evaluated with 2D speckle-tracking echocardiography were not statistically significantly correlated with the presence or absence of vitamin D deficiency.

Two-dimensional speckle-tracking echocardiographic evaluation of the longitudinal deformation of the left ventricular myocardium in patients with severe coronary artery tortuosity.

Coronary artery tortuosity (CAT) is an anatomical condition in which epicardial coronary arteries have abnormal curves or spiral courses. Although correlated with higher rates of positive stress test, its effects on the myocardial function remain to be clearly defined. We included in this cross-sectional study and evaluated with 2D speckle-tracking echocardiography 40 consecutive patients admitted to our hospital for selective coronary angiography which showed severe CAT without significant epicardial coronary artery stenosis, and 40 consecutive subjects matched for age, hypertension, and diabetes in whom selective coronary angiography showed neither CAT nor significant epicardial coronary artery stenosis. Systolic strain, strain rate, and early and late diastolic strain rates were not significantly different between the 2 groups, even after adjustment for potential confounding variables. The 2D speckle-tracking echocardiography-derived indices of longitudinal deformation of the left ventricular myocardium were not significantly different between the patients with severe CAT and controls.

Evaluation of the longitudinal deformation of the left ventricular myocardium in subjects with impaired fasting glucose with and without increased glycated hemoglobin.

ObjectivePrediabetes comprises a heterogeneous group because of the poor concordance of its definition. The aim of our study was to evaluate the longitudinal deformation of the left ventricular (LV) myocardium at the two opposite ends of the prediabetes spectrum as defined by fasting blood sugar and glycated hemoglobin (HbA1c).MethodsEighty consecutive subjects in a cross-sectional single-center study with impaired fasting glucose (IFG) (100–126 mg/dL) and without significant epicardial coronary artery stenosis seen on selective coronary angiography were included in our study and were divided into two groups based on their HbA1c levels (<5.7% and 5.7%–6.4%). The longitudinal deformation of the LV myocardium was compared between the two groups using two-dimensional speckle-tracking echocardiography (2DSTE).ResultsThe Student t-test, Mann–Whitney U test, or X2 test was used for data analysis, whichever was appropriate. The systolic strain (–16.1%±2.0 vs. –16.8%±2.4; p=0.214), systolic strain rate (–1.3±0.2 s–1 vs. –1.4±0.2 s–1; p=0.403), and early and late-diastolic strain rates (1.4±0.3 s–1 vs. 1.5±0.3 s–1; p=0.456 and 0.9±0.1 s–1 vs. 1.0±0.2 s–1; p=0.684, respectively) of the LV myocardium were not statistically different between the IFG subjects with and without increased HbA1c as detected using 2DSTE.ConclusionThe longitudinal deformation of the LV myocardium as detected using 2DSTE in the subjects without significant epicardial coronary artery stenosis was not statistically significantly different between the IFG subjects with and without increased HbA1c.

Cardiac pathologic findings in 3 unusual cases of sudden cardiac death related to anorexiant drugs

Amphetamine congeners can be prescribed as anorexiant drugs despite their potential adverse effects, including cardiac toxicity. However, the morphologic features of cardiac damage related to protracted use of these compounds are unknown. We provide a detailed description of cardiac autopsy findings in 3 cases of sudden death associated with protracted use of high doses of phendimetrazine and/or phenylpropanolamine or bupropion prescribed as anorexiants, in association with other compounds. The main cardiac findings were similar in all 3 cases: (1) mild-moderate hypertrophy of the left ventricle and/or the septum; (2) myocardial nonischemic scarring (midmural and/or subepicardial) appearing as discrete foci or with a bandlike morphology; (3) mild-moderate intramural small vessel disease in the absence of significant epicardial coronary artery stenosis; and (4) acute/recent inflammatory lesions consistent with toxic myocarditis. In summary, the detailed pathology examination of the heart in these 3 cases revealed myocardial lesions identical to those reported in catecholamine myocardial damage in all their various stages of evolution. In the presence of a clinical history of long-term intake of anorexiants of this category, it is most important at autopsy to recognize and correctly interpret the acute and chronic myocardial lesions of the type herein described because they represent an anatomical substrate for arrhythmic death.

Myocardial perfusion and left ventricular function indices assessed by gated myocardial perfusion SPECT in methamphetamine abusers.

Methamphetamine (MA) is associated with alterations of cardiac structure and function, although it is less known. In this study, we assessed possible abnormality in myocardial perfusion and left ventricular function using gated myocardial perfusion SPECT. Fifteen patients with MA abuse, on the basis of Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV) MA dependency determined by Structured Clinical Interview for DSM-IV, underwent 2-day dipyridamole stress/rest Tc-sestamibi gated myocardial perfusion SPECT. An average daily dose of MA use was 0.91±1.1 (0.2-4) g. The duration of MA use was 3.4±2.1 (1-7) years. In visual and semiquantitative analyses, all patients had normal gated myocardial perfusion SPECT, with no perfusion defects. In all gated SPECT images, there was no abnormality in left ventricular wall motion and thickening. All summed stress scores and summed rest scores were below 3. Calculated left ventricular functional indices including the end-diastolic volume, end-systolic volume, and left ventricular ejection fraction were normal. Many cardiac findings because of MA mentioned in previous reports are less likely because of significant epicardial coronary artery stenosis.

Myocardial perfusion is impaired in renal transplant and liver transplant patients

Methods We conducted a prospective study of 25 renal transplant (RT) recipients, 8 liver transplant (LT) recipients without previous CKD history and 7 controls with hypertension (HT). The transplant recipients were asymptomatic and had no previous ischaemic heart disease or revascularisation or systolic heart failure. The pre-transplant workup of the RT and LT were negative for haemodynamically significant epicardial coronary artery stenosis. Diabetes mellitus history between RT, LT and HT controls were not statistically different. Myocardial function, late-gadolinium enhancement and first-pass perfusion was assessed semiquantitatively at rest and under stress. The MPRI was calculated as the ratio of perfusion during adenosine-induced hyperemia to the rest perfusion. The RT and LT patients underwent whole-heart non-contrast magnetic resonance coronary angiography (MRCA) to assess the presence of proximal to mid epicardial coronary artery disease.

Acute coronary syndrome without critical epicardial coronary disease: prevalence, characteristics, and outcome

BackgroundAbsence of significant epicardial coronary artery stenosis in patients with acute onset of chest pain and elevation of myocardial necrosis markers is occasionally observed. The aim of this study was to retrospectively analyze the clinical characteristics and the outcome of such patients. MethodsAll patients with myocardial infarction (MI) but without significant coronary artery stenosis (≥50%) on angiography from May 2002 to April 2011 were compared with patients undergoing percutaneous coronary intervention due to non–ST-elevation MI (NSTEMI). ResultsOf 4311 consecutive patients with MI, 272 patients (6.3%) did not show significant coronary artery stenosis (group I) and were compared with 253 NSTEMI patients (group II). Younger age (61.9 ± 14.0 vs 65.4 ± 12.0 years; P = .003), female sex (49.3% vs 28.9%; P < .001), less severe anginal symptoms (Canadian Cardiovascular Society class III/IV 41.9% vs 49.8%; P = .05), lower level of myocardial necrosis marker (1.9 ± 6.7 vs 27.4 ± 68.7 ng/mL [troponin], 3.3 ± 4 vs 14.2 ± 20 mmol/L [creatine kinase]; P < .001 for both), and higher left ventricular ejection fraction (58.7% ± 12.6% vs 48.1% ± 12.4%; P < .01) were associated with group I patients. At a mean follow-up of 22.3 ± 22.9 months, all-cause and cardiac mortality was lower in group I patients (4.9% vs 14.3%; and 2.9% vs 10.1%; P < .01, for both). Event-free survival was more frequent in group I patients (58.4% vs 28.8%; P < .0001) and inversely related to the troponin level. ConclusionsAbsence of significant coronary stenosis accounts for a minority of patients presenting with MI and is associated with a better outcome compared to patients with NSTEMI, and the prognosis is inversely related to the troponin level.

Utility of coronary CT angiography in outpatients with hypertrophic cardiomyopathy presenting with angina symptoms

BackgroundAngina is a frequent symptom in patients with hypertrophic cardiomyopathy (HCM); however, it is often not because of significant epicardial coronary artery stenosis. Coronary CT angiography (CCTA) is an excellent modality to rule out significant coronary artery stenosis in the low- and intermediate-risk patients; however, its value in patients with HCM has not been explored. We sought to assess the utility of CCTA in the assessment of patients with HCM and stable anginal symptoms and compare the incidence of epicardial coronary artery stenosis to an age- and gender-matched control group. MethodsConsecutive outpatients with HCM referred for CCTA over a 3-year period because of stable anginal symptoms (chest pain or shortness of breath) were identified retrospectively. Age- and gender-matched patients without HCM referred for CCTA because of similar symptoms over a 6-month period were used as controls. All patients had CCTA using an Aquilion ONE 320 scanner. The coronary arteries were evaluated independently by 2 blinded observers, and any luminal narrowing was scored quantitatively as follows: >70% = severe; 50% to 70% = moderate; <50% = mild; and none. For the HCM group, results of cardiac single-photon emission CT (SPECT) or cardiac magnetic resonance perfusion studies as well as catheter angiograms were recorded where available. ResultsA total of 91 patients with HCM and 91 controls were included. No significant difference in cardiac risk factors was present between the 2 groups. The CCTA was of diagnostic quality in all patients. The median (interquartile range) calcium score was lower in patients with HCM (0 [0–50] vs 2 [0–189]) but did not reach statistical significance (P = .23). The incidence of moderate-to-severe coronary artery stenosis was significantly lower in patients with HCM than in controls (6.6% vs 33.0%; P < .001). The incidence of left anterior descending artery luminal narrowing overall was also significantly lower in the HCM patients (7.0% vs 20.9%; P = .002). There was a higher incidence of myocardial bridging in patients with HCM (40.7% vs 6.6%; P < .001), with longer and deeper bridged segments. Among a subgroup of HCM patients (n = 24) who had either stress perfusion CMR or cardiac single-photon emission CT studies performed, 15 of 24 had false-positive perfusion abnormalities without evidence of luminal obstruction on CCTA. ConclusionWe demonstrate the use of CCTA for the assessment of stable anginal symptoms in patients with HCM. The incidence of moderate-to-severe coronary artery stenosis was significantly lower in our HCM patients in comparison to our age-matched, gender-matched, and risk factor–matched control group. Given the high incidence of false-positive findings on perfusion stress studies, we propose that CCTA may be useful for appropriate triage to coronary angiography in the HCM patient with anginal symptoms.

Aortic valve stenosis is associated with reduced myocardial perfusion as assessed by videodensitometry in coronary angiograms

Aortic valve stenosis may be accompanied by angina despite coronary arteries free of significant stenosis due to microvascular abnormalities. The aim of the current study was to test whether densitometry-derived myocardial perfusion on coronary angiogram is reduced in patients with aortic valve stenosis. The study comprised 20 patients with aortic valve stenosis (mean transvalvular gradient: 47.4±15.2 mm Hg) and 30 control subjects without significant epicardial coronary artery stenosis. A quantitative parameter of myocardial perfusion was calculated by the ratio of maximal density (Gmax) and time to reach maximum density (Tmax) on time-density curves in regions of interest of each coronary artery on coronary angiograms. Mean three-vessel Gmax/Tmax proved to be significantly lower in patients with aortic valve stenosis compared to control subjects (2.55±1.02 1/sec vs. 3.39±1.09 1/sec, p<0.01). Reduced Gmax/Tmax values indicative of myocardial perfusion abnormalities as measured by densitometry on coronary angiograms could be demonstrated in patients with aortic valve stenosis compared to controls.

Acute coronary syndrome or apical ballooning syndrome?

Apical ballooning syndrome (ABS) is uniquely characterized by the acute onset of transient extensive kinesis of the apical and mid portions of the left ventricle without significant epicardial coronary artery stenosis, accompanied by chest symptoms and electrocardiogram changes similar to those of acute coronary syndrome. We report a case of ABS with severe coronary artery stenosis presenting as acute coronary syndrome after emotional stress. ABS should be considered a cause of left ventricular wall motion abnormalities even if a coronary arteriogram shows severe coronary artery stenosis.

Coronary microvascular endothelial function deteriorates late (12 months) after sirolimus-eluting stent implantation

Coronary flow velocity reserve (CFVR) may reflect coronary microvascular endothelial function in the absence of significant epicardial coronary artery stenosis. The purpose of this study was to evaluate coronary microvascular endothelial function late (6 and 12 months) after sirolimus-eluting stent (SES) implantation using transthoracic Doppler echocardiography. A total of 21 lesions from 21 patients with significant left anterior descending artery stenosis who underwent percutaneous coronary intervention (PCI) with SES were enrolled and studied. As a control group, 10 patients who were treated with bare metal stent (BMS) were also studied. CFVR was measured at 6 and 12 months after PCI. Coronary angiography was also performed at 6 and 12 months (SES only) after stenting. Between 6 and 12 months after SES implantation, there was no significant difference in angiographical diameter stenosis. On the other hand, CFVR significantly decreased between 6 and 12 months in the SES group (2.5±0.5 vs. 2.2±0.5, p<0.01), but not in the BMS group (2.3±0.4 vs. 2.5±0.3, p=0.1). Coronary microvascular endothelial function may deteriorate between 6 and 12 months after SES implantation.

Coronary blood flow in patients with end-stage renal disease assessed by thrombolysis in myocardial infarction frame count method

Myocardial ischaemia in patients with end-stage renal disease (ESRD) develops both due to the epicardial coronary artery stenosis and to the microvascular injury. We aimed to evaluate coronary blood flow in ESRD patients by means of the thrombolysis in myocardial infarction (TIMI) frame count method (TFC). In patients with ESRD, implementation of the TFC as a marker of the coronary flow abnormalities have not been previously investigated. Thirty-nine ESRD patients on regular dialysis underwent elective coronary angiography. Coronary artery stenosis >75% was defined as significant. TFC for the three main coronary vessels was calculated. Higher TFC values reflected slower flow. In 19 patients (49%), significant epicardial coronary artery disease was found. Distribution of the TFC for the three main coronary arteries reflected prevalence for higher TFC values. Mean corrected TFC for the left anterior descending artery (LAD) was 34.7 +/- 16, for the circumflex artery (Cx) 41.5 +/- 25 and for the right coronary artery (RCA) 30.9 +/- 18 frames. For the three main coronary vessels, there were no statistically significant differences between the mean TFC values according to the presence or absence of the severe coronary artery stenoses on angiography (LAD: 30.2 +/- 12 vs 36.3 +/- 18; Cx: 41.5 +/- 20 vs 41.5 +/- 27; RCA: 34.9 +/- 16 vs 30.0 +/- 19, respectively). Our results demonstrate for the first time the reduction in blood flow velocity, assessed with TFC method, in the coronary arteries of ESRD patients. This phenomenon was observed regardless of the presence of the significant epicardial coronary artery stenosis. Therefore, TFC cannot be applied as a marker of significant coronary artery stenosis in ESRD population.

Sequential Transthoracic Ultrasound Assessment of Coronary Flow Reserve in a Patient with Tako-tsubo Syndrome

We report a case of a 70-year-old woman with Tako-tsubo syndrome admitted to the hospital with typical chest pain and electrocardiogram changes in anterior precordial leads suggesting acute coronary syndrome. Coronary angiography demonstrated normal coronary artery and left ventriculography the typical apical ballooning of Tako-tsubo syndrome. Transthoracic echocardiographically derived coronary flow velocity reserve by adenosine was lower than normal (1.54) in the acute phase and improved after 1 month (2.68). At this time, electrocardiogram normalization also occurred. Our report supports the hypothesis that coronary microvascular dysfunction might be a determinant of Tako-tsubo syndrome.