Transthoracic Doppler echocardiography - noninvasive diagnostic window for coronary flow reserve assessment

Non-alcoholic fatty liver disease is associated with coronary flow reserve impairment: A pilot meta-analysis

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is estimated to affect approximately 25% of the global population. Both, coronary artery disease and NAFLD are linked to underlying insulin resistance and inflammation as drivers of the disease. Coronary flow reserve parameters, including coronary flow reserve velocity (CFRV), baseline diastolic peak flow velocity (DPFV), and hyperemic DPFV, are noninvasive markers of coronary microvascular circulation. The existing literature contains conflicting findings regarding these parameters in NAFLD patients.

METHODS

A comprehensive systematic search was conducted on major electronic databases from inception until May 8, 2024, to identify relevant studies. We pooled the standardized mean differences (SMD) with 95% confidence intervals (CI) using the inverse-variance random-effects model. Statistical significance was set at P < .05.

RESULTS

Four studies with 1139 participants (226 with NAFLD and 913 as controls) were included. NAFLD was associated with a significantly lower CFRV (SMD: -0.77; 95% CI: -1.19, -0.36; P < .0002) and hyperemic DPFV (SMD: -0.73; 95% CI: -1.03, -0.44; P < .00001) than the controls. NAFLD demonstrated a statistically insignificant trend toward a reduction in baseline DPFV (SMD: -0.09; 95% CI: -0.38, 0.19; P = .52) compared to healthy controls.

CONCLUSION

Patients with NAFLD are at a higher risk of coronary microvascular dysfunction, as demonstrated by reduced CFRV and hyperemic DPFV. The presence of abnormal coronary flow reserve in patients with NAFLD provides insights into the higher rates of cardiovascular disease in these patients. Early aggressive targeted interventions for impaired coronary flow reserve in subjects with NAFLD may lead to improvement in clinical outcomes.

Basing on the machine learning model to analyse the coronary calcification score and the coronary flow reserve score to evaluate the degree of coronary artery stenosis

AIM

To obtain the coronary artery calcium score (CACS) for each branch in coronary artery computed tomography angiography (CCTA) examination combined with the flow fraction reserve (FFR) of each branch in the coronary artery detected by CT and apply a machine learning model (ML) to analyse and predict the severity of coronary artery stenosis.

METHODS

All patients who underwent coronary computed tomography angiography (CCTA) from January 2019 to April 2022 in the HOSPITAL (T.C.M) AFFILIATED TO SOUTHWEST MEDICAL UNIVERSITY) were retrospectively screened, and their sex, age, characteristics of lipid-containing lesions, coronary calcium score (CACS) and CT-FFR values were collected. Five machine learning models, random forest (RF), k-nearest neighbour algorithm (KNN), kernel logistic regression, support vector machine (SVM) and radial basis function neural network (RBFNN), were used as predictive models to evaluate the severity of coronary stenosis.

RESULTS

Among the five machine learning models, the SVM model achieved the best prediction performance, and the prediction accuracy of mild stenosis was up to 90%. Second, age and male sex were important influencing factors of increasing CACS and decreasing CT-FFR. Moreover, the critical CACS value of myocardial ischemia >200.70 was calculated.

CONCLUSION

Through computer machine learning model analysis, we prove the importance of CACS and FFR in predicting coronary stenosis, especially the prominent vector machine model, which promotes the application of artificial intelligence computer learning methods in the field of medical analysis.

Temporal changes in coronary artery function and flow velocity reserve in mice exposed to chronic intermittent hypoxia

Study Objectives

Obstructive sleep apnea (OSA) is a chronic condition characterized by intermittent hypoxia (IH) that is implicated in an increased risk of cardiovascular disease (i.e., coronary heart disease, CHD) and associated with increased overall and cardiac-specific mortality. Accordingly, we tested the hypothesis that experimental IH progressively impairs coronary vascular function and in vivo coronary flow reserve.

Methods

Male C57BL/6J mice (8-week-old) were exposed to IH (FiO2 21% 90 s–6% 90 s) or room air (RA; 21%) 12 h/day during the light cycle for 2, 6, 16, and 28 weeks. Coronary artery flow velocity reserve (CFVR) was measured at each time point using a Doppler system. After euthanasia, coronary arteries were micro-dissected and mounted on wire myograph to assess reactivity to acetylcholine (ACh) and sodium nitroprusside (SNP).

Results

Endothelium-dependent coronary relaxation to ACh was preserved after 2 weeks of IH (80.6 ± 7.8%) compared to RA (87.8 ± 7.8%, p = 0.23), but was significantly impaired after 6 weeks of IH (58.7 ± 16.2%, p = 0.02). Compared to ACh responses at 6 weeks, endothelial dysfunction was more pronounced in mice exposed to 16 weeks (48.2 ± 5.3%) but did not worsen following 28 weeks of IH (44.8 ± 11.6%). A 2-week normoxic recovery after a 6-week IH exposure reversed the ACh abnormalities. CFVR was significantly reduced after 6 (p = 0.0006) and 28 weeks (p &lt; 0.0001) of IH when compared to controls.

Conclusion

Chronic IH emulating the hypoxia-re-oxygenation cycles of moderate-to-severe OSA promotes coronary artery endothelial dysfunction and CFVR reductions in mice, which progressively worsen until reaching asymptote between 16 and 28 weeks. Normoxic recovery after 6 weeks exposure reverses the vascular abnormalities.

Prognostic Value of Coronary Flow Reserve Obtained on Dobutamine Stress Echocardiography and its Correlation with Target Heart Rate

Background:

Normal coronary flow velocity reserve (CFVR) (≥ 2) obtained in the left anterior descending coronary artery (LAD) from transthoracic echocardiography is associated with a good prognosis, but there is no study correlating CFVR with submaximal target heart rate (HR).

Objective:

To evaluate the prognostic value of CFVR obtained in the LAD of patients with preserved (>50%) left ventricular ejection fraction (LVEF) who completed a dobutamine stress echocardiography (DSE), considering target HR.

Methods:

Prospective study of patients with preserved LVEF and CFVR obtained in the LAD who completed DSE. In Group I (GI = 31), normal CFVR was obtained before achieving target HR, and, in Group II (GII = 28), after that. Group III (G III=24) reached target HR, but CFVR was abnormal. Death, acute coronary insufficiency, coronary intervention, coronary angiography without further intervention, and hospitalization were considered events.

Results:

In 28 ± 4 months, there were 18 (21.6%) events: 6% (2/31) in GI, 18% (5/28) in GII, and 46% (11/24) in GIII. There were 4 (4.8%) deaths, 6 (7.2%) coronary interventions and 8 (9.6%) coronary angiographies without further intervention. In event-free survival by regression analysis, GIII had more events than GI (p < 0.001) and GII (p < 0.045), with no difference between GI and GII (p = 0.160). After adjustment, the only difference was between GIII and GI (p = 0.012).

Conclusion:

In patients with preserved LVEF and who completed their DSE, normal CFVR obtained before achieving target HR was associated with better prognosis.

Fundamento:

A reserva de velocidade de fluxo coronariano (RVFC) adequada (≥ 2) obtida na artéria descendente anterior (ADA) através do ecocardiograma transtorácico associa-se a bom prognóstico, mas não há estudo correlacionando-a com a frequência cardíaca (FC) alvo (submáxima).

Objetivo:

Avaliar o valor prognóstico da RVFC obtida na ADA de pacientes com fração de ejeção do ventrículo esquerdo (FEVE) preservada (>50%) e ecocardiograma sob estresse com dobutamina (EED) concluído, considerando a FC alvo submáxima.

Métodos:

studo prospectivo de pacientes com FEVE preservada e RVFC obtida na ADA durante EED concluído. No Grupo I (GI=31), a RVFC adequada foi obtida antes de se atingir a FC alvo, e no Grupo II (G II=28), após. O Grupo III (G III=24) atingiu a FC alvo, mas a RVFC foi inadequada. Foram considerados eventos: óbito, insuficiência coronariana aguda, intervenção coronariana, coronariografia sem intervenção subsequente e internamento hospitalar.

Resultados:

Em 28 ± 4 meses, ocorreram 18 (21,6%) eventos, sendo 6% (2/31) no GI, 18% (5/28) no GII e 46% (11/24) no GIII. Foram 4 (4,8%) óbitos, 6 (7,2%) intervenções coronarianas e 8 (9,6%) coronariografias sem intervenção subsequente. Na sobrevida livre de eventos pela análise de regressão, GIII apresentou mais eventos do que GI (p < 0,001) ou GII (p < 0,045), não havendo diferença entre GI e GII (p = 0,160). Após o ajustamento, foi mantida a diferença apenas entre GIII e GI (p = 0,012).

Conclusão:

Em pacientes com FEVE preservada e EED concluído, a RVFC adequada obtida antes da FC alvo associou-se ao melhor prognóstico.

Coronary Microvascular Dysfunction - Epidemiology, Pathogenesis, Prognosis, Diagnosis, Risk Factors and Therapy

Angina has traditionally been thought to be caused by obstructive coronary artery disease (CAD). However, a substantial number of patients with angina are found to not have obstructive CAD when undergoing coronary angiography. A significant proportion of these patients have coronary microvascular dysfunction (CMD), characterized by heightened sensitivity to vasoconstrictor stimuli and limited microvascular vasodilator capacity. With the advent of non-invasive and invasive techniques, the coronary microvasculature has been more extensively studied in the past 2 decades. CMD has been identified as a cause of cardiac ischemia, in addition to traditional atherosclerotic disease and vasospastic disease. CMD can occur alone or in the presence obstructive CAD. CMD shares many similar risk factors with macrovascular CAD. Diagnosis is achieved through detection of an attenuated response of coronary blood flow in response to vasodilatory agents. Imaging modalities such as cardiovascular magnetic resonance, positron emission tomography, and transthoracic Doppler echocardiography have become more widely used, but have not yet completely replaced the traditional intracoronary vasoreactivity testing. Treatment of CMD starts with lifestyle modification and risk factor control. The use of traditional antianginal, antiatherosclerotic medications and some novel agents may be beneficial; however, clinical trials are needed to assess the efficacy of the pharmacologic and non-pharmacologic therapeutic modalities. In addition, studies with longer-term follow-up are needed to determine the prognostic benefits of these agents. We review the epidemiology, prognosis, pathogenesis, diagnosis, risk factors and current therapies for CMD.

Coronary flow velocity reserve reduction is comparable in patients with erectile dysfunction and in patients with impaired fasting glucose or well-regulated diabetes mellitus

BACKGROUND

There is growing evidence that erectile dysfunction is a sentinel for future coronary artery disease. Recently published studies have shown signs of impaired coronary endothelial function in patients with erectile dysfunction, without clinical cardiovascular disease and diabetes. We evaluated the magnitude of coronary vasodilatory dysfunction in men with erectile dysfunction, as compared with men with impaired glucose metabolism (impaired fasting glucose or diabetes) and healthy controls.

METHODS

We investigated men aged 68-73 years with erectile dysfunction (n=12), age-matched men with impaired glucose metabolism, who all proved to have erectile dysfunction (n=15), and age-matched male controls (n=12). Erectile dysfunction was evaluated using the International Index of Erectile Function (IIEF)-5 questionnaire. Coronary flow velocity reserve in the left anterior descending artery was examined using Doppler ultrasound and intravenous adenosine provocation.

RESULTS

Coronary flow velocities at rest did not differ between the three groups, but maximum coronary flow velocity was significantly lower in the erectile dysfunction group (P=0.004) and in the impaired glucose metabolism group (P=0.019), as compared with controls. There was no difference between the erectile dysfunction and impaired glucose metabolism groups. Coronary flow velocity reserve was reduced in the erectile dysfunction group (P=0.026) compared to controls, but was similar compared to the impaired glucose metabolism group. In multivariate analysis including all groups, erectile dysfunction score was the only independent predictor of reduced coronary flow velocity reserve (P=0.020).

CONCLUSIONS

The magnitude of early coronary endothelial and smooth muscle cell dysfunction in otherwise healthy men with erectile dysfunction was comparable to that of patients with impaired glucose metabolism: a well known risk factor for coronary artery disease.

Diabetes mellitus and coronary microvascular function in asymptomatic patients with severe aortic stenosis and nonobstructed coronary arteries

BACKGROUND AND AIM

Coronary flow reserve is impaired in asymptomatic patients with aortic stenosis and has a prognostic value. We investigated whether the type II diabetes mellitus additionally impairs microvascular circulation assessed by coronary flow reserve in patients with asymptomatic severe aortic stenosis, normal left ventricular ejection fraction and nonobstructed coronary arteries.

METHODS

A total of 128 patients, mean age of 66.35 ± 10.51 (58.6% males), with severe aortic stenosis and normal left ventricular ejection fraction were enrolled in this study. Patients with diabetes mellitus, those who were treated for diabetes mellitus or had documentation confirming the diagnosis of diabetes mellitus, were considered. All patients underwent coronary angiography and had no obstructive coronary disease (defined as having no stenosis >50% in diameter), standard transthoracic Doppler-echocardiographic study and adenosine stress transthoracic echocardiography for coronary flow reserve measurement.

RESULTS

Diabetes mellitus was present in 26 patients (20.31%). There was no significant difference in aortic stenosis severity between diabetic and non-diabetic patients [aortic valve area (0.81 ± 0.18 vs 0.85 ± 0.15 cm(2)) and Vmax (4.20 ± 0.57 vs 4.21 ± 0.48 m/s)]. Mean coronary flow reserve in diabetic patients was 1.98 ± 0.48, while mean coronary flow reserve in non-diabetic patients was 2.64 ± 0.54 (p < 0.01). Diabetes mellitus was independent predictor of coronary flow reserve [B = -0.636, 95% confidence interval (-0.916 to -0.368), p < 0.001].

CONCLUSION

Diabetes mellitus additionally impairs coronary microvascular function in asymptomatic patients with severe aortic stenosis and nonobstructed coronary arteries.

Coronary Flow Velocity Reserve Assessment with Transthoracic Doppler Echocardiography

Coronary flow velocity reserve (CFVR) reflects global coronary atherosclerotic burden, endothelial function and state of the microvasculature. It could be measured using transthoracic Doppler echocardiography in a non-invasive, feasible, reliable and reproducible fashion, following a standardised protocol with different vasodilatory stimuli. CFVR measurement is a recommended complement to vasodilator stress echocardiography. It could serve as a diagnostic tool for coronary microvascular dysfunction and in the setting of epicardial coronary artery stenoses could help in identification and assessment of functional significance of coronary lesions and follow-up of patients after coronary interventions. CFVR has also a prognostic significance in different clinical situations.

Feasibility of proximal right coronary artery imaging by 2D and 3D echocardiography in comparison to coronary angiography

The present study was carried out to test the feasibility of proximal right coronary artery (RCA) imaging and to detect proximal RCA narrowing and occlusion by 2D and 3D transthoracic echocardiography in comparison to coronary angiography (CA). Standardised 2D and 3D echocardiography were performed prior to CA in 97 patients with sinus rhythm. The following parameters were determined: the longest longitudinal detectable RCA segment, the minimum and maximum width of the RCA, the area and number of detectable narrowing >50% of the proximal RCA and the correlation between the echocardiographic and angiographic findings. The visualisation of the proximal RCA and the detection of coronary artery narrowing in the proximal RCA are generally possible. Differences in width and area were not statistically significant between 2D and 3D echocardiography, but showed significant differences between echocardiography and CA. For the detection of proximal RCA narrowing, higher sensitivity and specificity values were obtained by 2D than by 3D echocardiography. However, in patients with sufficient image quality 3D echocardiography permits a more detailed visualisation of the anatomical proportions and an en-face view into the RCA ostium. The visualisation of the proximal RCA is feasible and narrowing can be detected by 2D and 3D echocardiography if image quality is sufficient. CA is the gold standard for the detection of coronary artery stenoses. However, the potential of this new approach is clinically important because crucial findings of the proximal RCA can be presumably detected non-invasively prior to CA.

Coronary microvascular dysfunction: sex-specific risk, diagnosis, and therapy

Cardiovascular disease is the leading cause of death worldwide. In the presence of signs and symptoms of myocardial ischaemia, women are more likely than men to have no obstructive coronary artery disease (CAD). Women have a greater burden of symptoms than men, and are often falsely reassured despite the presence of ischaemic heart disease because of a lack of obstructive CAD. Coronary microvascular dysfunction should be considered as an aetiology for ischaemic heart disease with signs and symptoms of myocardial ischaemia, but no obstructive CAD. Coronary microvascular dysfunction is defined as impaired coronary flow reserve owing to functional and/or structural abnormalities of the microcirculation, and is associated with an adverse cardiovascular prognosis. Therapeutic lifestyle changes as well as antiatherosclerotic and antianginal medications might be beneficial, but clinical outcome trials are needed to guide treatment. In this Review, we discuss the prevalence, presentation, diagnosis, and treatment of coronary microvascular dysfunction, with a particular emphasis on ischaemic heart disease in women.

Current Diagnostic and Therapeutic Strategies in Microvascular Angina

Microvascular angina is common among patients with signs and symptoms of acute coronary syndrome and is associated with an increased risk of cardiovascular and cerebrovascular events. Unfortunately, microvascular is often under-recognized in clinical settings. The diagnosis of microvascular angina relies on assessment of the functional status of the coronary microvasculature. Invasive strategies include acetylcholine provocation, intracoronary Doppler ultrasound, and intracoronary thermodilution; noninvasive strategies include cardiac positron emission tomography (PET), cardiac magnetic resonance, and Doppler echocardiography. Once the diagnosis of microvascular angina is established, treatment is focused on improving symptoms and reducing future risk of cardiovascular and cerebrovascular events. Pharmacologic options and lifestyle modifications for patients with microvascular angina are similar to those for patients with coronary artery disease.

Microvascular coronary dysfunction and ischemic heart disease: where are we in 2014?

Many patients with angina and signs of myocardial ischemia on stress testing have no significant obstructive epicardial coronary disease. There are many potential coronary and non-coronary mechanisms for ischemia without obstructive epicardial coronary disease, and prominent among these is coronary microvascular and/or endothelial dysfunction. Patients with coronary microvascular and/or endothelial dysfunction are often at increased risk of adverse cardiovascular events, including ischemic events and heart failure despite preserved ventricular systolic function. In this article, we will review the diagnosis and treatment of coronary microvascular and endothelial dysfunction, discuss their potential contribution to heart failure with preserved ejection fraction, and highlight recent advances in the evaluation of atherosclerotic morphology in these patients, many of whom have non-obstructive epicardial disease.

Does mild renal failure affect coronary flow reserve after coronary artery bypass graft surgery?

INTRODUCTION

There are only a limited number of studies on the link between mild renal failure and coronary artery disease. The purpose of this study is to investigate the effects of mild renal failure on the distal vascular bed by measuring the coronary flow reserve (CFR) in transthoracic echocardiography after coronary artery bypass grafting (CABG).

METHODS

The study included 52 consecutive patients (12 women and 40 men) who had undergone uncomplicated CABG. The patients were divided into 2 groups. Group 1 included patients with a preoperative glomerular filtration rate (GFR) of 60-90 (mild renal failure), and group 2 included those with a GFR >90. The CFR measurements were carried out through a second harmonic transthoracic Doppler echocardiography.

RESULTS

The mean age was 60.08 ± 1.56 years in group 1 and 60.33 ± 1.19 in group 2. The mean preoperative CFR was 1.79 ± 0.06 in group 1 and 2.05 ± 0.09 in group 2. The mean postoperative CFR was 2.09 ± 0.08 in group 1 and 2.37 ± 0.06 in group 2. There was a statistically significant difference between the 2 groups as to preoperative creatinine clearance, preoperative estimated GFR, postoperative day 7 creatinine clearance, postoperative month 6 creatinine clearance, postoperative day 7 estimated GFR, postoperative month 6 estimated GFR, preoperative CFR, and postoperative CFR (P < .05). CFR was found to be unaffected by the choice of on-pump or off-pump technique (P = .907). After bypass surgery, there was a significant increase in the mean postoperative CFR, when compared with the mean preoperative CFR (P = .001).

CONCLUSION

In our study, we detected a decrease in CFR in patients with mild renal failure. We believe that in patients undergoing CABG for coronary artery disease, mild renal failure can produce adverse effects due to deterioration of the microvascular bed.

Coronary flow velocity reserve during dobutamine stress echocardiography

BACKGROUND

A coronary flow velocity reserve (CFVR)≥2 is adequate to infer a favorable prognosis or the absence of significant coronary artery disease.

OBJECTIVE

To identify parameters which are relevant to obtain CFVR (adequate or inadequate) in the left anterior descending coronary artery (LAD) during dobutamine stress echocardiography (DSE).

METHODS

100 patients referred for detection of myocardial ischemia by DSE were evaluated; they were instructed to discontinue the use of β-blockers 72 hours prior to the test. CFVR was calculated as a ratio of the diastolic peak velocity (cm/s) (DPV) on DSE (DPV-DSE) to baseline DPV at rest (DPV-Rest). In group I, CFVR was <2 and, in group II, CFVR was ≥2. The Fisher's exact test and Student's t test were used for the statistical analyses. P values<0.05 were considered statistically significant.

RESULTS

At rest, the time (in seconds) to obtain Doppler in LAD in groups I and II was not different (53±31 vs. 45±32; p=0.23). During DSE, LAD was recorded in 92 patients. Group I patients were older (65.9±9.3 vs. 61.2±10.8 years; p=0.04), had lower ejection fraction (61±10 vs. 66±6%; p=0.005), higher DPV-Rest (36.81±08 vs. 25.63±06 cm/s; p<0.0001) and lower CFVR (1.67±0.24 vs. 2.53±0.57; p<0.0001), but no difference was observed regarding DPVDSE (61.40±16 vs. 64.23±16 cm/s; p=0.42). β-blocker discontinuation was associated with a 4-fold higher chance of a CFVR<2 (OR= 4; 95% CI [1.171-13.63], p=0.027).

CONCLUSION

DPV-Rest was the main parameter to determine an adequate CFVR. β-blocker discontinuation was significantly associated with inadequate CFVR. The high feasibility and the time to record the LAD corroborate the use of this methodology.

Stress echocardiography

Stress echocardiography is the combination of 2D echocardiography with a physical, pharmacological or electrical stress. The diagnostic end point for the detection of myocardial ischemia is the induction of a transient worsening in regional function during stress. Stress echocardiography provides similar diagnostic and prognostic accuracy as radionuclide stress perfusion imaging but at a substantially lower cost, without environmental impact and with no biohazards for the patient and the physician. In spite of its dependence upon operator's training, it is the best possible choice to achieve the still elusive target of sustainable cardiac imaging in the field of noninvasive diagnosis of coronary artery disease.

Association between serum γ-glutamyltransferase levels and coronary microvascular function

BACKGROUND

Serum γ-glutamyltransferase (GGT) level is an independent risk factor for cardiovascular (CV) disease, and there is a strong association between serum GGT levels and most CV risk factors. However, the role of the serum GGT level as an independent risk factor for coronary microvascular function remains controversial.

PURPOSE

We aimed to determine whether the serum GGT level is independently and specifically associated with coronary flow reserve (CFR) impairment in normal individuals.

METHODS

We examined healthy individuals who did not have any major CV risk factors (277), of whom CFR was achieved in 263 (95%). They were divided into three groups according to serum GGT levels. In each participant, CFR was measured using an Acuson Sequoia C256 Echocardiography System.

RESULTS

Participants with high GGT levels had significantly impaired CFR compared with those with intermediate and low GGT levels (2.82±0.49 vs. 2.71±0.51 and 2.44±0.48 U/l; P<0.0001). After adjusting for potential confounders, including sex, BMI, blood pressure, lipids, and glucose, we found that the serum GGT and high-sensitivity C-reactive protein levels were associated independently with CFR impairment (b=-0.205, P=0.007; b=-0.172, P=0.024). We also found that the serum GGT level was a good predictor of low CFR at the receiver-operating characteristic curve. The area under the curve was 75% [95% confidence interval, 0.65-0.86], and the serum GGT level was significantly predictive of a low CFR (P<0.0001).

CONCLUSIONS

These results support a role for the serum GGT level as an independent marker of coronary microvascular damage and inflammation in normal individuals without concomitant risk factors.

Association between serum total antioxidant status and coronary microvascular functions in patients with SLE

Mortality from cardiovascular disease has been found to be increased in patients with systemic lupus erythematosus (SLE). Coronary flow reserve (CFR) measurement is used both to assess epicardial coronary arteries and to examine the integrity of coronary microvascular circulation. Oxidative stress, enhancing modification of plasma lipids, is also associated with atherosclerotic events in lupus patients. Impairment of CFR and TAS has been shown to be an early manifestation of coronary atherosclerosis. Forty patients with SLE and 33 healthy volunteers were included in this study. Echocardiographic examination included left ventricular myocardial velocity measurements and coronary flow reserve (CFR) measurement. Serum total antioxidant status levels (TAS) also were measured using TAS kit. Lateral myocardial early peak velocity (Em) and lateral Em/Am ratio did not differ between the groups, but lateral myocardial atrial peak velocity (Am) was significantly higher in SLE group than the control group. Baseline coronary diastolic peak flow velocity (DPFV) of left anterior descending was similar in both the groups. However, hyperemic DPFV and CFR (2.50 ± 0.42 vs. 3.09 ± 0.45, P < 0.0001) were significantly lower in the SLE group than in the control group. CFR significantly and inversely correlated with CRP and significantly correlated with TAS. Subclinical coronary microvascular dysfunction can occur in SLE patients without traditional cardiovascular risk factors, probably associated with underlying inflammation and impairment of TAS.

Disproportionally impaired microvascular structure in essential hypertension

BACKGROUND

Increased microvascular resistance and small artery remodelling are key abnormalities in the pathophysiology of essential hypertension. We investigated the relation between the impairment of coronary and forearm minimum vascular resistances (C-Rmin and F-Rmin) and the degree of hypertension.

METHOD

Seventy-five never-treated essential hypertension patients with 24-h systolic blood pressure (BP) at least 130 mmHg or diastolic BP at least 80 mmHg were assigned into grade 1 (office BP 140/90-159/99 mmHg) and grade 2 (office BP 160/100-179/109 mmHg) hypertension and compared to normotensive controls (n = 25). The patients were (48 years, 60% men) without cardiovascular disease. C-Rmin and coronary flow reserve (CFR) were derived from flow measurements in the left anterior descending artery using transthoracic echocardiography. F-Rmin was measured using venous occlusion plethysmography. Resting systemic vascular resistance index (SVRI) was measured with a gas rebreathing technique.

RESULTS

Compared to normotensive controls: 24-h mean BP was raised 14% in grade 1 essential hypertension and 28% in grade 2 essential hypertension, whereas F-Rmin and C-Rmin were elevated by 58 and 87% in grade 1 essential hypertension and 72 and 125% in grade 2 essential hypertension. C-Rmin and F-Rmin were thus both increased more than expected from the BP level. SVRI and left-ventricular mass were increased proportionally to the BP. CFR was decreased by approximately 30% in both essential hypertension groups.

CONCLUSION

The results demonstrate excessive microvascular structural abnormalities in hypertension suggesting microvascular alterations occur early and not just as an adaptation to the BP level. Thus the level of BP elevation does not give an accurate indication of the microvascular involvement and impairment in essential hypertension.

Coronary flow reserve, strain and strain rate imaging during pharmacological stress before and after percutaneous coronary intervention: comparison and correlation

INTRODUCTION

Coronary flow reserve (CFR) could apply reliable information about the coronary circulation, and strain (S) and strain rate imaging (SRI) are able to quantify the left ventricular myocardial performance. The aim of this study was to assess myocardial performance in relation to the function of the coronary circulation before and after successful percutaneous coronary intervention (PCI) of the left anterior descending artery.

MATERIAL AND METHOD

Fourteen patients (10 men, 4 women, mean age 53.2 ± 11.4 years) with severe left anterior descending stenosis who had a successful selective PCI were recruited into this study. CFR and myocardial deformity indices (S and SR) were recorded before and after percutaneous intervention, both at rest and during stress echo test.

RESULTS

CFR, S, and SR increased after intervention significantly. There was significant correlation between CFR ratio and poststress systolic strain (SS) ratio and early diastolic strain rate (ESR) ratio (P < 0.05 and r > 0.6). Also CFR improvement had significant relationship with changes of poststress Systolic SR and poststress Systolic S (P < 0.05 and r > 0.6). Based on regression analysis the amount of change in CFR was independently associated with change in SS during stress and systolic SR.

CONCLUSION

PCI improves CFR (a marker of coronary perfusion), strain, and strain rate (markers of regional cardiac wall deformation). The independent association between CFR improvement and poststress systolic strain and strain rate means that SRI parameters can independently predict CFR changes after PCI.

Target heart rate to determine the normal value of coronary flow reserve during dobutamine stress echocardiography

BACKGROUND

The determination of coronary flow reserve (CFR) is an essential concept at the moment of decision-making in ischemic heart disease. There are several direct and indirect tests to evaluate this parameter. In this sense, dobutamine stress echocardiography is one of the pharmacological method most commonly used worldwide. It has been previously demonstrated that CFR can be determined by this technique. Despite our wide experience with dobutamine stress echocardiography, we ignored the necessary heart rate to consider sufficient the test for the analysis of CFR. For this reason, our main goal was to determine the velocity of coronary flow in each stage of dobutamine stress echocardiography and the heart rate value necessary to double the baseline values of coronary flow velocity in the territory of the left anterior descending (LAD) coronary artery.

METHODS

A total of 33 consecutive patients were analyzed. The patients included had low risk for coronary artery disease. All the participants underwent dobutamine stress echocardiography and coronary artery flow velocity was evaluated in the distal segment of LAD coronary artery using transthoracic color-Doppler echocardiography.

RESULTS

The feasibility of determining CFR in the territory of the LAD during dobutamine stress echocardiography was high: 31/33 patients (94%). Mean CFR was 2.67 at de end of dobutamine test.There was an excellent concordance between delta HR (difference between baseline HR and maximum HR) and the increase in the CFR (correlation coefficient 0.84). In this sense, we found that when HR increased by 50 beats, CFR was ≥ 2 (CI 93-99.2%). In addition, 96.4% of patients reached a CFR ≥ 2 (IC 91.1 - 99%) at 75% of their predicted maximum heart rate.

CONCLUSIONS

We found that the feasibility of dobutamine stress echocardiography to determine CFR in the territory of the LAD coronary artery was high. In this study, it was necessary to achieve a difference of 50 bpm from baseline HR or at least 75% of the maximum predicted heart rate to consider sufficient the test for the analysis of CFR.

Coronary flow reserve is impaired in patients with nonalcoholic fatty liver disease: association with liver fibrosis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is associated with an increased risk of cardiovascular disease. Coronary flow reserve (CFR) is widely used to examine the integrity of coronary microvascular circulation. We evaluated the prevalence of impaired CFR in patients with biopsy-proven NAFLD. We also investigated the independent clinical, biochemical, and liver histology predictors of CFR in the setting of NAFLD.

METHODS

Fifty-nine consecutive patients with NAFLD and 77 age- and gender-matched controls were evaluated. CFR recordings were performed by transthoracic Doppler harmonic echocardiography. CFR>or=2.0 was considered normal.

RESULTS

CFR was significantly lower in patients with NAFLD than in controls (2.11+/-0.45 vs. 2.52+/-0.62, P<0.001). An impaired CFR (i.e. <2) was found in 25 NAFLD patients (42.4%) whereas all controls had normal CFR values (P<0.001). A stepwise linear regression analysis in NAFLD patients identified liver fibrosis scores as the only independent predictor of CFR values (beta=-0.60; t=-2.44, P=0.021).

CONCLUSION

Our findings indicate that in patients with biopsy-proven NAFLD: (a) an abnormal CFR is found in approximately 42.4% of cases, and (b) liver fibrosis scores are an independent predictor of depressed CFR.

Current issues in coronary stent technology

Coronary artery stents have become the medical device of choice for the treatment of coronary artery disease. Since their introduction in 1987, significant advances in stent technology have taken place. A major objective of these developments was the reduction of in-stent restenosis, the formation of neointimal tissue inside the stent triggered by vessel injury and the inflammatory response, which results in renarrowing of the coronary artery. Improvements in strut configuration, thickness, and materials have enhanced deliverability and reduced vessel damage. Currently available drug-eluting stents release drugs that reduce neointimal formation through the arrest of cell proliferation. Drug-eluting stents have significantly reduced rates of in-stent restenosis. However, concerns have been raised with respect to their long-term safety, particularly in relation to the occurrence of late thrombosis. The post-procedural monitoring of stent-related complications is also of interest, including the relative suitability of invasive techniques such as angiography and intravascular ultrasound, and non-invasive techniques such as computed tomography and magnetic resonance imaging scanning. This paper reviews the current issues in stent technology.

Cardiovascular prognostic value of vascular involvement in Behcet's disease

We measured carotid artery intima-media thickness (IMT), brachial artery flow mediated dilation (FMD), and coronary flow reserve (CFR) in 38 Behcet's disease (BD) patients without vascular involvement, 15 BD patients with vascular involvement, and 35 control subjects. BD patients with and without vascular involvement were similar regarding carotid IMT (0.52+/-0.14; 0.51+/-0.09; 0.46+/-0.09; P=0.051), and brachial FMD (16.3+/-6.8; 16.5+/-9.1). CFR values were significantly impaired in BD patients compared to the controls; however the BD patients with and without vascular involvement were similar regarding CFR (2.66+/-0.45; 2.62+/-0.48; 2.91+/-0.53, P=0.007 with and without vascular involvement and the controls, respectively). Endothelial and coronary microvascular functions are compromised in BD patients without vascular involvement as remarkably as that in patients with vascular involvement.

Transthoracic echocardiographic imaging of coronary arteries: tips, traps, and pitfalls

The aim of this paper is to highlight coronary investigation by transthoracic Doppler evaluation. This application has recently been introduced into clinical practice and has received enthusiastic feedback in terms of coronary flow reserve evaluation on left anterior coronary artery disease diagnosis. Such diagnosis represents the most important clinical application but has in itself some limitations regarding anatomical and technological knowledge. The purpose of this paper is to offer a didactic approach on how to investigate the different segments of left anterior and posterior descending coronary arteries by transthoracic ultrasound using different anatomical key structures .as markers

We will conclude by underlining that, nowadays, innovative technology allows complete evaluation of both major coronary arteries in many patients in a resting condition as well as during pharmacology stress-tests, but we often do not know it.

Impaired coronary microvascular function and increased intima-media thickness in rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is associated with excessive cardiovascular mortality. Recently, some studies have shown endothelial dysfunction in RA patients with high inflammatory activity. In addition, it has been suggested that the chronic inflammatory state of RA contributes to accelerated atherosclerosis. Therefore, we aimed to evaluate whether coronary microvascular dysfunction and increased carotid artery intima-media thickness exist in patients with a long history and well controlled disease activity of RA lacking traditional cardiovascular risk factors.

METHODS

Thirty RA patients (22 women; mean age 43.7+/-9.0) and 52 healthy volunteers (38 women; mean age 45.3+/-5.4) were included into the study. Using transthoracic echocardiography, each subject underwent echocardiographic examination including coronary flow reserve (CFR) and carotid intima-media thickness (IMT) measurement.

RESULTS

CFR values were statistically reduced for RA patients as compared to controls (2.4+/-0.5 vs. 2.7+/-0.4, P=0.002) whereas IMT values were significantly increased (0.6+/-0.1 vs. 0.5+/-0.1, P=0.001). In RA patients, CFR positively correlated with lateral Em/Am ratio (r=0.399, P=0.029), and negatively correlated with lateral isovolumic relaxation time (IVRT) (r=-0.744, P=0.005), IMT (r=-0.542, P=0.002) and RA disease duration (r=-0.495, P=0.005). Reflecting LV diastolic function, mitral E-wave deceleration time and isovolumic relaxation time were borderline significant between the groups, however lateral Em/Am ratio and lateral IVRT were statistically different.

CONCLUSIONS

Patients with RA had impaired CFR and increased carotid IMT, and these injurious effects correlated significantly with disease duration.

Preclinical impairment of coronary flow reserve in patients with rheumatoid arthritis

Cardiovascular involvement in rheumatoid arthritis (RA) is common, although the true prevalence of cardiac abnormalities is difficult to measure, as much disease remains clinically silent. The pathogenesis of cardiac lesions in RA is related to the primary disorder of microcirculation with diffuse arteriolar and capillary lesions. Previous studies demonstrated that coronary flow reserve (CFR) is impaired in patients with connective tissue diseases (CTD). This review focuses on transthoracic Doppler echocardiography as a noninvasive method used to assess CFR in RA patients. CFR is early reduced in RA patients without clinical evidence of heart disease as a result of impaired microcirculation. CFR seems a useful technique able to follow-up and to assess effects of new drugs on RA patients.

Echocardiographic and hemodynamic determinants of right coronary artery flow reserve and phasic flow pattern in advanced non-ischemic cardiomyopathy

Background

In patients with advanced non-ischemic cardiomyopathy (NIC), right-sided cardiac disturbances has prognostic implications. Right coronary artery (RCA) flow pattern and flow reserve (CFR) are not well known in this setting. The purpose of this study was to assess, in human advanced NIC, the RCA phasic flow pattern and CFR, also under right-sided cardiac disturbances, and compare with left coronary circulation. As well as to investigate any correlation between the cardiac structural, mechanical and hemodynamic parameters with RCA phasic flow pattern or CFR.

Methods

Twenty four patients with dilated severe NIC were evaluated non-invasively, even by echocardiography, and also by cardiac catheterization, inclusive with Swan-Ganz catheter. Intracoronary Doppler (Flowire) data was obtained in RCA and left anterior descendent coronary artery (LAD) before and after adenosine. Resting RCA phasic pattern (diastolic/systolic) was compared between subgroups with and without pulmonary hypertension, and with and without right ventricular (RV) dysfunction; and also with LAD. RCA-CFR was compared with LAD, as well as in those subgroups. Pearson's correlation analysis was accomplished among echocardiographic (including LV fractional shortening, mass index, end systolic wall stress) more hemodynamic parameters with RCA phasic flow pattern or RCA-CFR.

Results

LV fractional shortening and end diastolic diameter were 15.3 ± 3.5 % and 69.4 ± 12.2 mm. Resting RCA phasic pattern had no difference comparing subgroups with vs. without pulmonary hypertension (1.45 vs. 1.29, p = NS) either with vs. without RV dysfunction (1.47 vs. 1.23, p = NS); RCA vs. LAD was 1.35 vs. 2.85 (p < 0.001). It had no significant correlation among any cardiac mechanical or hemodynamic parameter with RCA-CFR or RCA flow pattern. RCA-CFR had no difference compared with LAD (3.38 vs. 3.34, p = NS), as well as in pulmonary hypertension (3.09 vs. 3.10, p = NS) either in RV dysfunction (3.06 vs. 3.22, p = NS) subgroups.

Conclusion

In patients with chronic advanced NIC, RCA phasic flow pattern has a mild diastolic predominance, less marked than in LAD, with no effects from pulmonary artery hypertension or RV dysfunction. There is no significant correlation between any cardiac mechanical-structural or hemodynamic parameter with RCA-CFR or RCA phasic flow pattern. RCA flow reserve is still similar to LAD, independently of those right-sided cardiac disturbances.

Impaired coronary microvascular function in familial Mediterranean fever

BACKGROUND

Patients with inflammatory rheumatic diseases have an increased risk of developing atherosclerosis. However, the question of whether patients with familial Mediterranean fever (FMF) are at risk of atherosclerosis and related diseases remains controversial.

OBJECTIVE

We aimed to use transthoracic Doppler echocardiography to investigate coronary flow reserve (CFR) and left ventricular (LV) diastolic function in patients with FMF.

METHODS

CFR and LV diastolic function were studied in 33 patients with FMF (16 men, 17 women; mean age, 36.7+/-12.0 years) and 35 healthy volunteers (20 men, 15 women; mean age, 36.8+/-5.2 years). Coronary diastolic peak flow velocities (DPFV) were measured at baseline and after dipyridamole infusion. LV diastolic function was assessed by standard and tissue Doppler imaging.

RESULTS

CFR was significantly lower in the FMF group than in the control group (2.27+/-0.38 versus 3.02+/-0.50, P<0.0001). Significant between-group differences were found regarding LV diastolic function mitral E/A ratio, mitral E-wave deceleration time, and lateral A(m). Serum high sensitivity C-reactive protein (hsCRP) levels were significantly higher in the patients with FMF, and hsCRP values independently correlated with CFR.

CONCLUSIONS

Coronary microvascular function and LV diastolic function are impaired in patients with FMF. The severity of these impairments is correlated with hsCRP. Impaired CFR may be an early manifestation of cardiac involvement in patients with FMF.

Coronary flow velocity changes in response to hypercapnia: assessment by transthoracic Doppler echocardiography

BACKGROUND

The effects of hypercapnia on coronary arteries in human beings are not known. We used transthoracic Doppler echocardiography to evaluate coronary blood flow velocity (CFV) changes in response to hypercapnia in healthy adults.

METHODS

Twenty adults underwent transthoracic Doppler echocardiography of the left anterior descending coronary artery while breathing room air, 40% fraction of inspired oxygen, and 40% fraction of inspired oxygen with carbon dioxide supplemented to end-tidal tensions of +5, +7.5, and +10 mm Hg above baseline.

RESULTS

Mean (SD) diastolic peak CFV values for these conditions were 23.1 (9.1), 23.0 (9.0), 25.5 (9.3), 27.9 (11.5), and 31.5 (13.0) cm/s, respectively. Significant overall differences between conditions (P < .001) and progressive levels of hypercapnia (P < or = .01) were observed. CFV increases remained significant after adjusting for increases in cardiac output (P = .038).

CONCLUSIONS

CFV increases with hypercapnia. This is the first report of human coronary artery flow responses to hypercapnia. Transthoracic Doppler echocardiography methodology is feasible for measuring CFV and the effects of hypercapnia on the coronary circulation.

Light cigarette smoking impairs coronary microvascular functions as severely as smoking regular cigarettes

BACKGROUND

Smoking is the most prevalent and most preventable risk factor for cardiovascular diseases. Smoking low-tar, low-nicotine cigarettes (light cigarettes) would be expected to be less hazardous than smoking regular cigarettes owing to the lower nicotine and tar yield.

OBJECTIVE

To compare the chronic and acute effects of light cigarette and regular cigarette smoking on coronary flow velocity reserve (CFVR).

METHODS

20 regular cigarette smokers (mean (SD) age 24.8 (5.0)), 20 light cigarette smokers (mean age 25.6 (6.4)), and 22 non-smoker healthy volunteers (mean age 25.1 (4.2)) were included. First, each subject underwent echocardiographic examination, including CFVR measurement, after a 12 hour fasting and smokeless period. Two days later, each subject smoked two of their normal cigarettes in a closed room within 15 minutes. Finally, within 20-30 minutes, each subject underwent an echocardiographic examination, including CFVR measurement.

RESULTS

Mean (SD) CFVR values were similar in light cigarette and regular cigarette smokers and significantly lower than in the controls (2.68 (0.50), 2.65 (0.61), 3.11 (0.53), p = 0.013). Before and after smoking a paired t test showed that smoking two light cigarettes acutely decreased the CFVR from 2.68 (0.50) to 2.05 (0.43) (p = 0.001), and smoking of two regular cigarettes acutely decreased CFVR from 2.65 (0.61) to 2.18 (0.48) (p = 0.001).

CONCLUSION

Smoking low-tar, low-nicotine cigarettes impairs the CFVR as severely as smoking regular cigarettes. CFVR values are similar in light cigarette and regular cigarette smokers and significantly lower than in controls.

Adiponectin in severe preeclampsia

AIMS

Adiponectin is an adipokine with insulin-sensitizing, anti-atherogenic, anti-inflammatory and angiogenic properties. The aims of this study were to determine whether maternal plasma adiponectin concentrations differ between patients with severe preeclampsia and those with normal pregnancies, and to explore the relationship between plasma adiponectin and the results of Doppler velocimetry of the uterine arteries.

METHODS

This case-control study included two groups: (1) patients with severe preeclampsia (n=50) and (2) patients with normal pregnancies (n=150). Pulsed-wave and color Doppler ultrasound examination of the uterine arteries were performed. Plasma adiponectin concentrations were determined by ELISA. Non-parametric statistics were used for analysis.

RESULTS

(1) Patients with severe preeclampsia had a higher median plasma concentration of adiponectin than that of normal pregnant women. (2) The median plasma adiponectin concentration did not differ between women with severe preeclampsia who had a high impedance to blood flow in the uterine arteries and those with normal impedance to blood flow. (3) Among patients with normal pregnancies, plasma adiponectin concentrations were negatively correlated with BMI in the first trimester and at sampling.

CONCLUSIONS

Women with severe preeclampsia have a higher median plasma concentration of adiponectin than that of normal pregnant women. This may reflect a compensatory feedback mechanism to the metabolically-altered, anti-angiogenic and pro-atherogenic state of severe preeclampsia.

Patients with Behcet's disease carry a higher risk for microvascular involvement in active disease period

BACKGROUND

Behcet's disease (BD) is characterized with remissions and exacerbations. However, to date, there is no study to investigate a possible association of disease activity (active versus inactive disease period) with cardiovascular complications.

METHODS

Forty patients with BD were evaluated in both active and in inactive disease period. For the control group 45 healthy volunteers, age and sex matched, were registered. Subjects with at least a 15-day lesion-free period were regarded in inactive disease period, and subjects with any oral, skin, and/or genital lesion was regarded as in active disease period. In each subject coronary diastolic peak flow velocities (DPFV) were measured at baseline and after dipyridamole infusion (0.84 mg/kg over 6 minutes) using an Acuson Sequoia C256 echocardiography system. Coronary flow reserve (CFR) was defined as the ratio of hyperemic to baseline DPFV.

RESULTS

CFR values were significantly lower in BD patients compared to the controls (2.57+/-0.50 versus 2.87+/-0.53, P = 0.006). In active disease period, basal DPFV (24.6+/-7.5 versus 27.3+/-6.6, P = 0.019) was significantly higher than in the inactive disease period. In the active disease period hyperemic DPFV (61.7+/-14.9 versus 56.8+/-16.7, P = 0.015) values decreased significantly. Therefore, in the active disease period CFR significantly decreased from 2.57+/-0.50 to 2.09+/-0.46, P<0.001. The only independent predictor of CFR within the active disease period was the disease duration (beta = -0.384, P = 0.012).

CONCLUSION

Within the active disease period, coronary microvascular function is more prominently impaired in BD patients. Therefore, BD patients are possibly more vulnerable to cardiovascular manifestations when they are in an active disease period.

Erectile dysfunction in healthy subjects predicts reduced coronary flow velocity reserve

BACKGROUND

Erectile dysfunction is associated with, and may be the first sign of coronary artery disease. We aimed to assess whether men with erectile dysfunction but without cardiovascular disease have reduced coronary flow reserve, as a sign of early coronary atherosclerosis.

METHODS

We investigated 12 men aged 68-73 years with erectile dysfunction, and 12 age-matched controls. Erectile function was evaluated using the validated IIEF-5 questionnaire. A score < or = 18 (of 25) was defined as erectile dysfunction and > or = 21 was considered normal. Patients with neurological or psychological reasons for erectile dysfunction were excluded, as were patients with symptoms of or prescribed medication for cardiovascular disease, hypertension or diabetes. Coronary flow velocity reserve was measured non-invasively by Doppler in the left anterior descending artery, before and during adenosine infusion.

RESULTS

Coronary flow velocity reserve was significantly reduced in subjects with erectile dysfunction: 2.36 versus 3.19; P=0.024. In logistic regression analysis, compared to control subjects, men with erectile dysfunction had significantly increased risk of reduced coronary flow velocity reserve (< or = 3.0): odds ratio 15.4, P=0.02. In multivariate analysis, adjusting for age, tobacco use, systolic blood pressure, heart rate and body mass index, erectile dysfunction was the only significant predictor of reduced coronary flow velocity reserve, P=0.016.

CONCLUSIONS

Men with erectile dysfunction but without diabetes or clinical cardiovascular disease have early signs of coronary artery disease. Our findings suggest that a cardiac risk evaluation may be indicated in men with suspected vasculogenic erectile dysfunction, and these individuals should be considered for primary prevention measures regarding cardiovascular disease risk factors.

Endothelial dysfunction, intima–media thickness and coronary reserve in relation to risk factors and Framingham score in patients without clinical atherosclerosis

BACKGROUND

Endothelial dysfunction, decreased coronary flow reserve (CFR) and increased intima-media thickness (IMT) are related to atherosclerosis and can be assessed non-invasively by echography.

OBJECTIVES

In order to describe the relationship between these parameters and with cardiovascular risk, this study investigated them simultaneously in patients without clinical atherosclerosis.

METHODS

A total of 106 subjects were studied, 91 with and 15 without cardiovascular risk factors. Cardiovascular disease was excluded in all cases. Doppler ultrasound was used to analyse endothelium-dependent vascular dilation in the brachial artery, IMT in the common carotid artery and CFR in the left anterior artery.

RESULTS

Patients with cardiovascular risk factors had impaired flow-mediated dilation (FMD; 3.7 +/- 3.2 versus 11.6 +/- 4.4%, P = 0.000); greater IMT (0.89 +/- 0.3 versus 0.56 +/- 0.14 mm, P = 0.000) and lower CFR (2.7 +/- 0.9 versus 4 +/- 1.2, P = 0.000). Correlation was found between IMT and FMD r = -0.240, (P = 0.013), IMT and CFR, r = -0.384 (P = 0.000), and between FMD and CFR of r = 0.289 (P = 0.007). All patients with IMT greater than 1 mm showed depressed FMD, most of them with low values of CFR, but patients with reduced FMD or CFR did not necessarily show increased IMT. There was a significant correlation between the three parameters and the Framingham risk score. Multiple linear regression analysis showed that IMT was the only factor related to the Framingham score.

CONCLUSION

In patients without clinical atherosclerotic disease, cardiovascular risk factors are associated with impaired FMD, CFR and increased IMT. Even though a correlation between these changes was found, they showed different dependence on cardiovascular risk factors and with global risk, IMT being the best correlated with the Framingham score.

Metformin therapy improves coronary microvascular function in patients with polycystic ovary syndrome and insulin resistance

BACKGROUND

Women with polycystic ovary syndrome (PCOS) are thought to have increased cardiovascular risk. Metformin therapy reduces whole-body insulin resistance (IR) in patients with type-2 diabetes mellitus (DM).

OBJECTIVE

As insulin resistance accompanying PCOS may be reversed by metformin therapy, we hypothesized that metformin therapy might improve coronary microvascular functions in women with PCOS and IR.

PATIENTS AND METHODS

We treated 16 women with PCOS and IR with metformin, and measured coronary flow reserve (CFR) at the beginning and after 6 months of metformin therapy using transthoracic second-harmonic Doppler echocardiography.

RESULTS

At the end of the 6 months of metformin therapy, baseline coronary diastolic peak flow velocity (DPFV) did not change significantly (from 24.6 +/- 4.3 to 23.0 +/- 3.1, P = 0.106); however, hyperaemic coronary DPFV (from 68.2 +/- 12.7 to 74.5 +/- 9.7, P = 0.08), and CFR (from 2.75 +/- 0.48 to 3.3 +/- 0.5, P = 0.016) was significantly improved by metformin therapy.

CONCLUSION

In women with PCOS, coronary microvascular function and CFR are significantly improved by 6 months of therapy with metformin.

Coronary flow reserve evaluation in stress-echocardiography laboratory

The assessment of coronary flow reserve by transthoracic echocardiography has recently been introduced into clinical practice with good results for the diagnosis of left anterior descending artery disease and fairly promising results for posterior descending coronary artery disease. By looking at what is behind wall motion, we may realize a sonographer's dream and, in particular, the addition of coronary flow reserve to regional wall motion analysis allows us to have - in the same sitting - high specificity (regional wall motion) and a highly sensitive (coronary flow reserve) diagnostic marker, with an improvement in overall diagnostic accuracy. Coronary flow reserve evaluation may shift the balance of stress choice in favor of vasodilators, which are easier to perform with dual imaging than dobutamine or exercise coronary flow reserve evaluation and may shift the choice in favor of dipyridamole or adenosine stress tests, which are also easier to perform with dual imaging than those using dobutamine or exercise. Lastly, it adds quantitative support to the exquisitely qualitative assessment of wall motion analysis, thereby facilitating the communication of stress echo results to the cardiological world outside the echo laboratory.

Determinants of coronary flow velocity reserve in healthy young men

The objective of this study was to identify risk markers for attenuated coronary flow velocity reserve (CFVR) that exist in healthy young men without evident atherosclerotic risk factors. Coronary blood flow velocity was measured with transthoracic Doppler echocardiography at baseline and during adenosine infusion in 37 healthy nonsmoking men [mean age, 27 yr (SD 4.0)]. Body composition and distribution of fat tissue were assessed with anthropometric measures and regulation of fat metabolism by determination of adiponectin and leptin levels. Physical performance capacity was tested with ergospirometry. The mean body mass index was 23 kg/m2 (SD 1.9), waist-to-hip ratio was 0.84 (SD 0.04), and CFVR was 3.5 (SD 0.61). Obesity indexes at study outset, leptin, adiponectin, maximal load (Max load in W/kg) and maximal oxygen consumption (Vo2 peak in ml x kg(-1) x min(-1)) in ergospirometry, rate-pressure product, and heart rate at rest were significantly associated with CFVR. In multivariate analysis, Max load (in W/kg) and waist-to-hip ratio were the only independent predictors of CFVR. We found no relationship between CFVR and serum lipids or body mass index. We conclude that abdominal fat accumulation and low aerobic fitness are independently associated with CFVR in men.

Do young women with polycystic ovary syndrome show early evidence of preclinical coronary artery disease?

BACKGROUND

It is thought that women with polycystic ovary syndrome (PCOS) are at increased risk of developing cardiovascular diseases.

METHODS

In this study, we used transthoracic echocardiography to measure coronary flow reserve (CFR) in 28 women with PCOS and in 26 healthy women.

RESULTS

The PCOS and the control groups were similar in terms of age (27.1 +/- 4.5 versus 28.8 +/- 4.4 years) and BMI (26.6 +/- 5.7 versus 24.7 +/- 4.4 kg/m2). Fasting insulin levels and homeostasis model assessment insulin resistance index were higher in the PCOS group. LH, the LH/FSH ratio, total testosterone, free testosterone and androstenedione were higher in the PCOS group. FSH, estradiol, prolactin, progesterone, cholesterol, triglyceride and high-sensitive C-reactive protein were similar between the two groups, but homocysteine levels were higher in the PCOS group. Baseline diastolic peak f low velocity (DPFV) (25.0 +/- 4.6 versus 23.3 +/- 2.7 cm/s, P > 0.05), hyperaemic DPFV (71.2 +/- 12.8 versus 73.0 +/- 12.9 cm/s, P > 0.05) and CFR (2.8 +/- 0.8 versus 3.2 +/- 0.8 cm/s, P > 0.05) of the left anterior descending coronary artery were similar between the two groups.

CONCLUSION

We conclude that in young women with PCOS and without cardiovascular risk factors, CFR is preserved.

Cardiac imaging techniques in systemic autoimmune diseases

Systemic autoimmune disorders are frequently associated to cardiac involvement and to a high prevalence of ischemic coronary events, often occurring at a younger age than in the normal population. Large increase in mortality is related to premature atherosclerosis with coronary artery disease and stroke in patients with connective tissue diseases. Coronary heart disease is responsible for 40-50% of the deaths of patients with rheumatoid arthritis. Transesophageal or transthoracic echocardiography are the most useful and noninvasive techniques able to detect not only valvular abnormalities, embolic sources or pulmonary hypertension, but also left ventricular systolic or diastolic dysfunction. Furthermore, the introduction of new indexes, contrast agents and software increased the accuracy of this technique. It is possible now to evaluate coronary flow reserve by transthoracic echocardiography in patients with systemic autoimmune disease in order to detect microvasculature disorder. However, an ischemic response in a symptomatic patient requires, in most cases, further evaluation with cardiac catheterization. Coronary artery imaging allows confirmation of the presence, extent and position of atheromatous lesions. More recently, other imaging modalities including magnetic resonance and computerized tomography angiography have been developed to allow imaging of the coronary arteries.

Quantitative assessment of harmonic power doppler myocardial perfusion imaging with intravenous Levovist in patients with myocardial infarction: comparison with myocardial viability evaluated by coronary flow reserve and coronary flow pattern of infarct-related artery

Background

Myocardial contrast echocardiography and coronary flow velocity pattern with a rapid diastolic deceleration time after percutaneous coronary intervention has been reported to be useful in assessing microvascular damage in patients with acute myocardial infarction.

Aim

To evaluate myocardial contrast echocardiography with harmonic power Doppler imaging, coronary flow velocity reserve and coronary artery flow pattern in predicting functional recovery by using transthoracic echocardiography.

Methods

Thirty patients with anterior acute myocardial infarction underwent myocardial contrast echocardiography at rest and during hyperemia and were quantitatively analyzed by the peak color pixel intensity ratio of the risk area to the control area (PIR). Coronary flow pattern was measured using transthoracic echocardiography in the distal portion of left anterior descending artery within 24 hours after recanalization and we assessed deceleration time of diastolic flow velocity. Coronary flow velocity reserve was calculated two weeks after acute myocardial infarction. Left ventricular end-diastolic volumes and ejection fraction by angiography were computed.

Results

Pts were divided into 2 groups according to the deceleration time of coronary artery flow pattern (Group A; 20 pts with deceleration time ≧ 600 msec, Group B; 10 pts with deceleration time < 600 msec). In acute phase, there were no significant differences in left ventricular end-diastolic volume and ejection fraction (Left ventricular end-diastolic volume 112 ± 33 vs. 146 ± 38 ml, ejection fraction 50 ± 7 vs. 45 ± 9 %; group A vs. B). However, left ventricular end-diastolic volume in Group B was significantly larger than that in Group A (192 ± 39 vs. 114 ± 30 ml, p < 0.01), and ejection fraction in Group B was significantly lower than that in Group A (39 ± 9 vs. 52 ± 7%, p < 0.01) at 6 months. PIR and coronary flow velocity reserve of Group A were higher than Group B (PIR, at rest: 0.668 ± 0.178 vs. 0.248 ± 0.015, p < 0.0001: during hyperemia 0.725 ± 0.194 vs. 0.295 ± 0.107, p < 0.0001; coronary flow velocity reserve, 2.60 ± 0.80 vs. 1.31 ± 0.29, p = 0.0002, respectively).

Conclusion

The preserved microvasculature detecting by myocardial contrast echocardiography and coronary flow velocity reserve is related to functional recovery after acute myocardial infarction.

The non-invasive documentation of coronary microcirculation impairment: role of transthoracic echocardiography

Transthoracic Doppler echocardiographic-derived coronary flow reserve is an useful hemodynamic index to assess dysfunction of coronary microcirculation. Isolated coronary microvascular abnormalities are overt by reduced coronary flow reserve despite normal epicardial coronary arteries. These abnormalities may occur in several diseases (arterial hypertension, diabetes mellitus, hypercholesterolemia, syndrome X, aortic valve disease, hypertrophic cardiomyopathy and idiopathic dilated cardiomyopathy). The prognostic role of impaired microvascular coronary flow reserve has been shown unfavourable especially in hypertrophic or idiopathic dilated cardiomyopathies. Coronary flow reserve reduction may be reversible, for instance after regression of left ventricular hypertrophy subsequent to valve replacement in patients with aortic stenosis, after anti-hypertensive treatment or using cholesterol lowering drugs. Coronary flow reserve may increase by 30% or more after pharmacological therapy and achieve normal level >3.0. In contrast to other non invasive tools as positron emission tomography, very expensive and associated with radiation exposure, transthoracic Doppler-derived coronary flow reserve is equally non invasive but cheaper, very accessible and prone to a reliable exploration of coronary microvascular territories, otherwise not detectable by invasive coronary angiography, able to visualize only large epicardial arteries.