Altered transmural contractility in postmenopausal women affected by cardiac syndrome X

Echocardiographic assessment of primary microvascular angina and primary coronary microvascular dysfunction

There is an increasing interest in the role of echocardiography in the evaluation of primary microvascular angina, which is attributed to primary coronary microvascular dysfunction. Valid echocardiographic techniques are expected to facilitate the diagnosis and follow-up of these patients and would be valuable for research purposes and therapy evaluation. However, adequate echocardiographic data are lacking, and the interpretation of the limited available literature is hindered by the previous addition of microvascular angina under more inclusive entities, such as cardiac syndrome X. In experienced hands, the assessment of primary coronary microvascular dysfunction in patients with suspected primary microvascular angina, using multiple echocardiographic techniques is feasible, relatively inexpensive, and safe. Exclusion of obstructive epicardial coronary artery disease is, however, a prerequisite for diagnosis. Two-dimensional transthoracic echocardiography, routine stress echocardiography, and speckle-tracking echocardiography indirectly assess primary coronary microvascular dysfunction by evaluating potential impairment in myocardial function and lack diagnostic sensitivity and specificity. Conversely, certain echocardiographic techniques, including Doppler-derived coronary flow velocity reserve and myocardial contrast echocardiography, assess some coronary microvascular dysfunction parameters and have exhibited diagnostic and prognostic potentials. Doppler-derived coronary flow velocity reserve is the best studied and only guideline-approved echocardiographic technique for documenting coronary microvascular dysfunction in patients with suspected microvascular angina. Myocardial contrast echocardiography, by comparison, can detect heterogeneous and patchy myocardial involvement by coronary microvascular dysfunction, which is an advantage over the common practice of coronary flow velocity reserve assessment in a single vessel (commonly the left anterior descending artery) which only reflects regional microvascular function. However, there is no consensus regarding the diagnostic criteria, and expertise performing this technique is limited. Echocardiography remains underexplored and inadequately utilized in the setting of microvascular angina and coronary microvascular dysfunction. Appraisal of the current echocardiographic literature regarding coronary microvascular dysfunction and microvascular angina is important to stay current with the progress in its clinical recognition and create a basis for future research and technological advancements.

Coronary microvascular dysfunction affects left ventricular global longitudinal strain response to dipyridamole stress echocardiography: a pilot study

The aim is to investigate, by means of speckle tracking echocardiography, left ventricular (LV) contractile function at rest and during dipyridamole stress in patients with coronary microvascular dysfunction (CMD). 59 patients (39% women, mean age 65.6 ± 6.1 years) with history of chest pain and without obstructive coronary artery disease (CAD) underwent dipyridamole stress echocardiography. Coronary flow was assessed in the left anterior descending coronary artery. Coronary flow reserve (CFR) was determined as the ratio of hyperaemic to baseline diastolic coronary flow velocity. CMD was defined as CFR < 2. Global longitudinal strain (GLS) was measured at rest and at peak dose. Nineteen patients (32%) among the overall population showed CMD. Baseline GLS was significantly lower in patients with CMD (- 16.8 ± 2.7 vs. - 19.1 ± 3.1, p < 0.01). A different contractile response to dipyridamole infusion was observed between the two groups: GLS significantly increased up to peak dose in patients without CMD (from - 19.1 ± 3.1 to - 20.2 ± 3.1, p < 0.01), and significantly decreased in patients with CMD (from - 16.8 ± 2.7 to - 15.8 ± 2.7, p < 0.01). There was a significant inverse correlation between CFR and ∆GLS (r = - 0.82, p < 0.01). Rest GLS and GLS response to dipyridamole stress are markedly impaired among patients with chest pain syndrome, non-obstructive CAD and CMD, reflecting subclinical LV systolic dysfunction and lack of LV contractile reserve due to underlying myocardial ischemia.

Role of different echocardiographic modalities in the assessment of microvascular function in women with ischemia and no obstructive coronary arteries

This review summarizes current knowledge about echocardiographic modalities used to assess microvascular function and left ventricular (LV) systolic function in women with ischemia and no obstructive coronary arteries (INOCA). Although the entire pathophysiological background of this clinical entity still remains elusive, it is primarily linked to microvascular dysfunction which can be assessed by coronary flow velocity reserve. Subtle impairments of LV systolic function in women with INOCA are difficult to assess by interpretation of wall motion abnormalities. LV longitudinal function impairment is considered to be an early marker of subclinical systolic dysfunction and can be assessed by global longitudinal strain quantification.

Impairment of coronary flow velocity reserve and global longitudinal strain in women with cardiac syndrome X and slow coronary flow

BACKGROUND

Microvascular dysfunction (MVD) is associated with adverse prognosis and may account for abnormal stress tests and angina symptoms in women with cardiac syndrome X (CSX). The aim of our study was to assess MVD by coronary flow velocity reserve (CFVR) and left ventricular (LV) contractile function by LV global longitudinal strain (LVGLS) in CSX patients with respect to presence of slow coronary flow (SCF). It was of additional importance to evaluate clinical status of CSX patients using Seattle Angina Questionnaire.

METHODS AND RESULTS

Study population included 70 women with CSX (mean age 61 ± 7 years) and 34 age-matched controls. CSX group was stratified into two subgroups depending on SCF presence: CSX-Thrombolysis In Myocardial Infarction (TIMI) 3- normal flow subgroup (n = 38) and CSX-TIMI 2- SCF subgroup (n = 32) as defined by coronary angiography. LVGLS measurements and CFVR of left anterior descending (LAD) and posterior descending (PD) artery were performed. CFVR-LAD and PD were markedly impaired in CSX group compared to controls (2.34 ± 0.25 vs 3.05 ± 0.21, p < 0.001; 2.32 ± 0.24 vs 3.01 ± 0.13, p < 0.001), and furthermore decreased in CSX-TIMI 2 patients. Resting, peak, and ΔLVGLS were all significantly impaired in CSX group compared to controls (for all p < 0.001), and furthermore reduced in CSX-TIMI 2 subgroup. Strongest correlation was found between peak LVGLS and CFVR LAD (r = -0.784, p < 0.001) and PD (r = -0.772, p < 0.001). CSX-TIMI 2 subgroup had more frequent angina symptoms and more impaired quality of life.

CONCLUSIONS

MVD in CSX patients is demonstrated by reduction in CFVR and LVGLS values. SCF implies more profound impairment of microvascular and LV systolic function along with worse clinical presentation.

Layer-specific distribution of myocardial deformation from anthracycline-induced cardiotoxicity in patients with breast cancer-From bedside to bench

BACKGROUND

Anthracycline anticancer drugs such as epirubicin and doxorubicin may induce myocardial dysfunction, leading to poor prognosis. Early detection of minor left ventricular (LV) myocardial dysfunction is important for the prevention of anthracylcine-induced cardiotoxicity. Using layer-specific speckle tracking echocardiography (STE), we investigated the progressive distribution of myocardial dysfunction in both breast cancer patients and an animal toxicity model.

METHODS

Patients with preserved LV ejection fraction (LVEF) preparing for epirubicin chemotherapy (N = 125) were prospectively enrolled. Layer-specific STE, including LV longitudinal and circumferential strains on subepicardium and subendocardium, were evaluated at baseline and after the first cycle, third cycle and six months of epirubicin therapy. A decline of LVEF above 10% to <55% at six months was defined as cardiotoxicity. These same strain measures were obtained in doxorubicin-treated rats and the distribution of myocardial fibrosis evaluated.

RESULTS

In patients developing cardiotoxicity, LV longitudinal strain on subendocardium (LVLSendo) was significantly reduced after three cycles of therapy despite no significant changes in conventional LV systolic, diastolic parameters as well as LV circumferential strains at that moment. Compared to conventional echocardiographic parameters, LVLSendo was significantly predictive of cardiotoxicity. Declines in LVLSendo were also observed in doxorubicin-treated rats at an early stage. These reductions also predicted significant fibrosis in the subendocardial layer.

CONCLUSION

LVLSendo is useful for the early detection of minor cardiac dysfunction during chemotherapy, thereby implicating endocardial involvement in the development of cardiotoxicity.

Early ischemia identification employing 2D speckle tracking selective layers analysis during dobutamine stress echocardiography

PURPOSE

Two-dimensional (2D) strain derived from speckle tracking proved to be feasible and accurate in the quantitative evaluation of myocardial ischemia during stress echocardiography. We compared the accuracy in detecting myocardial ischemia of the transmural segmental analysis with an endocardial specific evaluation in 20 patients undergoing dobutamine stress echocardiography (DSE) and coronary angiography.

METHODS

Peak systolic global strain (G-ε) and at the subendocardial level (Endo-ε) were measured off-line at rest, a low dose, and peak stress; then, we compared the results with wall-motion analysis and significant coronary artery disease (CAD > 70% diameter stenosis). Endocardial strain variation from basal to low and peak dose was computed both for global or subendocardial analysis. The utilization of the ROC curve allowed us to derive optimal cutoffs, sensibility and specificity for ischemic segments.

RESULTS

The subendocardial analysis at high dose showed to be able to increase significantly the accuracy of the test to detect the ischemic segments (sens 90.2% vs 85.4%; spec 93.1% vs 92.2%). Moreover, at the low dose, the subendocardial analysis showed to be able to increase significantly, mostly the specificity of the test (sens 69.6% vs 68.3%; spec 92.2% vs 86.2%). Notably, the strain subendocardial analysis at low dose showed to reach a high specificity, similar to the peak dose transmural analysis.

CONCLUSIONS

Measurement of subendocardial strain during DSE is feasible and can increase the accuracy of the test. Moreover, the subendocardial strain during DSE can reach a high specificity, even limiting the test at a low dose infusion.

Diagnostic Approach to Patients with Stable Angina and No Obstructive Coronary Arteries

The diagnosis of microvascular angina (MVA) is usually considered in patients presenting with angina symptoms and evidence of MI on non-invasive stress tests but normal coronary arteries at angiography. A definitive diagnosis of MVA, however, would require the presence of coronary microvascular dysfunction. Several invasive (e.g. intracoronary Doppler wire recording and thermodilution) and non-invasive (e.g. PET, cardiac MRI, transthoracic Doppler echocardiography) methods can be applied to obtain a diagnosis. Both endothelium-dependent and -independent coronary microvascular dilator function, as well as increased microvascular constrictor activity, should be investigated. The main issues in the assessment of clinical and diagnostic findings in patients with suspected MVA are discussed and a diagnostic approach is suggested.

Coronary microvascular dysfunction and myocardial contractile reserve in women with angina and no obstructive coronary artery disease

BACKGROUND

Coronary microvascular dysfunction (CMD) is a potential cause of myocardial ischemia and may affect myocardial function at rest and during stress. We investigated whether CMD was associated with left ventricular diastolic and systolic function at rest and during pharmacologically induced hyperemic stress.

METHODS

In a prospective cohort study, we included 963 women with angina, left ventricular ejection fraction (LVEF) >45%, and an invasive coronary angiogram without significant stenosis (<50%). Parameters of left ventricular diastolic function, LVEF, speckle tracking-derived global longitudinal strain (GLS), and coronary flow velocity reserve (CFVR) were assessed by transthoracic echocardiography at rest and during dipyridamole stress. The GLS and LVEF reserves were defined as the absolute increases in GLS and LVEF during stress.

RESULTS

Coronary flow velocity reserve (CFVR) was measured in 919 women of whom 26% had CMD (defined as CFVR < 2). Coronary microvascular dysfunction (CMD) was associated with higher age and a higher resting heart rate. Women with CMD had a reduced GLS reserve (P = .005), while we found no association between CFVR and LVEF at rest, GLS at rest, or the LVEF reserve, respectively. Global longitudinal strain (GLS) reserve remained associated with CFVR (P = .002) in a multivariable regression analysis adjusted for age, hemodynamic variables, and GLS at rest. In age-adjusted analysis, women with low CFVR had no signs of left ventricular diastolic dysfunction measured by echocardiography at rest.

CONCLUSION

The GLS reserve was significantly lower in women with CMD. The mechanisms underlying the association between CMD and GLS reserve warrant further study.

Physical training improves myocardial perfusion but not left ventricular function response to exercise in patients with microvascular angina

BACKGROUND

Patients with primary microvascular angina (PMA) commonly exhibit abnormal left ventricular function (LVF) during exercise, potentially owing to myocardial ischemia. Herein, we investigated in PMA patients the effect of the reduction of myocardial perfusion disorders, by using aerobic physical training, upon LVF response to exercise.

METHODS

Overall, 15 patients (mean age, 53.7±8.9 years) with PMA and 15 healthy controls (mean age, 51.0±9.4 years) were studied. All subjects were subjected to baseline resting and exercise ventriculography, myocardial perfusion scintigraphy (MPS), and cardiopulmonary testing. PMA group members then participated in a 4-month physical training program and were reevaluated via the same methods applied at baseline.

RESULTS

Baseline left ventricular ejection fraction (LVEF) determinations by ventriculography were similar for both groups (PMA, 67.7±10.2%; controls, 66.5±5.4%; P=0.67). However, a significant rise in LVEF seen in control subjects during exercise (75.3±6.2%; P=0.0001) did not materialize during peak exercise in patients with PMA (67.7±10.2%; P=0.47). Of the 12 patients in the PMA group who completed the training program, 10 showed a significant reduction in reversible perfusion defects during MPS. Nevertheless, LVEF at rest (63.5±8.7%) and at peak exercise (67.3±15.9%) did not differ significantly (P=0.30) in this subset.

CONCLUSIONS

In patients with PMA, reduced left ventricular inotropic reserve observed during exercise did not normalize after improving myocardial perfusion through aerobic physical training.

Timing of the negative effects of trastuzumab on cardiac mechanics after anthracycline chemotherapy

Trastuzumab (TZB) has been shown to be extremely effective in breast cancer patients over-expressing HER-2, but careful cardiac monitoring is required when TZB is administered with anthracyclines, since the combination can increase its toxicity. Myocardial deformation indexes associated with speckle tracking echocardiography (STE) have proven to be very sensitive in identifying early myocardial dysfunction. An observational, prospective study was designed to assess TZB-induced cardiac damage using STE in patients with HER-2 positive breast cancer who had been sequentially treated with TZB following epirubicin (EPI). Conventional echocardiographic parameters and STE deformation indexes (longitudinal, radial, and circumferential strain/strain rate and apical rotation) were analyzed at baseline, after each EPI treatment, and 1 week after every other dose of TZB administration until 1 year follow up, in order to focus on the timing and extent of myocardial impairment. In the forty-five enrolled patients, a reduction in subendocardial function after EPI treatment was observed by a significant impairment of the global longitudinal strain/strain rate (GLS/SR), while a significant increase in the activity of the subepicardial fibers was highlighted by an increase in apical rotation. After the second TZB dose, a sudden reduction of the apical rotation was seen, together with circumferential and radial strain/SR. Most importantly, the extent to which the apical rotation increased and decreased was found to strictly correlate with the GLS reduction at follow up. We found that after EPI therapy, subendocardial function was impaired, even while a compensatory increase in apical rotation occurred. Following TZB treatment, we observed impairment in apical rotation, which seems to be the first sign of global LV dysfunction predicting GLS reduction found at the end of treatment.

Layer-specific analysis of left ventricular myocardial contractility in patients with coronary slow-flow phenomenon

PURPOSE

Coronary slow-flow phenomenon (CSFP) is an angiographic diagnosis characterized by delayed coronary opacification in the absence of significant epicardial coronary stenosis. We previously reported impaired left ventricular (LV) function in patients with CSFP. However, the LV wall comprises three myocardial layers whose contractility can be differently affected. Therefore, we evaluated layer-specific (endocardial, mid-myocardial, and epicardial) LV myocardial contractility and assessed its relationships with the number of affected coronary arteries and their flow.

METHODS

We studied 60 patients with CSFP and 46 controls. CSFP was diagnosed by thrombolysis in myocardial infarction frame count. Echocardiography was performed within 72 hours after the coronary angiography. LV layer-specific longitudinal strain (LS) was measured using two-dimensional speckle-tracking echocardiography.

RESULTS AND CONCLUSIONS

The LS of all three myocardial layers was lower in patients with CSFP than in controls. In patients with CSFP, LS of all three myocardial layers and transmural LS gradient correlated negatively with the number of affected coronary arteries and the mean thrombolysis in myocardial infarction frame count. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:429-436, 2016.

Effects of Metformin and Exercise Training, Alone or in Combination, on Cardiac Function in Individuals with Insulin Resistance

Introduction

In patients affected by insulin resistance (IR), metformin (MET) therapy has been shown to exert its positive effects by improving glucose tolerance and preventing the evolution to diabetes. Recently, it was shown that the addition of metformin to physical training did not improve sensitivity to insulin or peak oxygen consumption (peak VO2). The purpose of this study was to establish the effect of metformin and exercise, separately or in combination, on systolic left ventricular (LV) function in individuals with IR.

Methods

Seventy-five patients with IR were enrolled and subsequently assigned to MET, combination MET and exercise, or exercise alone. The LV systolic and diastolic functions were evaluated with standard echocardiography tissue Doppler imaging (TDI) and speckle tracking echocardiography at baseline and after 12 weeks of treatment.

Results

MET, administered alone or in association with exercise, improved longitudinal LV function, as evidenced by an increase in systolic (S) wave on TDI, alongside increases in longitudinal global strain and strain rate in comparison to the group undergoing physical training alone. The traditional echocardiographic parameters showed no statistically significant differences among the three groups before or after the different cycles of therapy.

Conclusions

Treatment with MET, either with or without exercise, but not exercise alone, produced a significant increase in global longitudinal LV systolic function at rest. These findings validate the observation that the use of MET alone or in association with exercise has a crucial role to counteract the negative effects of IR on cardiovascular function.

Electronic supplementary material

The online version of this article (doi:10.1007/s40119-016-0057-3) contains supplementary material, which is available to authorized users.

Metabolomic approach to profile functional and metabolic changes in heart failure

Background

Heart failure (HF) is characterized by a series of adaptive changes in energy metabolism. The use of metabolomics enables the parallel assessment of a wide range of metabolites. In this study, we appraised whether metabolic changes correlate with HF severity, assessed as an impairment of functional contractility, and attempted to interpret the role of metabolic changes in determining systolic dysfunction.

Methods

A 500 MHz proton nuclear magnetic resonance (¹H-NMR)-based analysis was performed on blood samples from three groups of individuals: 9 control subjects (Group A), 9 HF patients with mild to moderate impairment of left ventricle ejection fraction (LVEF: 41.9 ± 4.0 %; Group B), and 15 HF patients with severe LVEF impairment (25.3 ± 10.3 %; Group C). In order to create a descriptive model of HF, a supervised orthogonal projection on latent structures discriminant analysis (OPLS-DA) was applied using speckle tracking-derived longitudinal strain rate as the Y-variable in the multivariate analysis.

Results

OPLS-DA identified three metabolic clusters related to the studied groups achieving good values for R² [R²(X) = 0.64; R²(Y) = 0.59] and Q² (0.39). The most important metabolites implicated in the clustering were 2-hydroxybutyrate, glycine, methylmalonate, and myo-inositol.

Conclusions

The results demonstrate the suitability of metabolomics in combination with functional evaluation techniques in HF staging. This innovative tool should facilitate investigation of perturbed metabolic pathways in HF and their correlation with the impairment of myocardial function.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-015-0661-3) contains supplementary material, which is available to authorized users.

Role of echocardiography in the management of cardiac disease in women

The widespread use of echocardiography has contributed to the early recognition of several distinct cardiac diseases in women. During pregnancy, safe monitoring of the disease process, as well as a better understanding of hemodynamics, is possible. During the use of potentially cardiotoxic drugs for breast cancer chemotherapy, echocardiographic patient monitoring is vital. Compared to men, the addition of an imaging modality to routine electrocardiogram monitoring during stress testing is more informative for diagnosing coronary disease in women. This review briefly discusses the role of echocardiography in the management of several women-specific cardiac diseases where echocardiography plays a pivotal role in disease management.

Effects of an aquatic-based exercise program to improve cardiometabolic profile, quality of life, and physical activity levels in men with type 2 diabetes mellitus

BACKGROUND

The role of structured exercise in improving cardiometabolic profile and quality of life in patients with type 2 diabetes mellitus (2DM) has been widely demonstrated. Little is known about the effects of an aquatic-based exercise program in patients with 2DM.

OBJECTIVE

To evaluate the effects of a supervised aquatic-based exercise program on cardiometabolic profile, quality of life, and physical activity levels in patients with 2DM.

DESIGN AND SETTING

Observational study, community pre-post aquatic-based exercise program, primary care intervention.

PATIENTS

Eighteen men diagnosed with 2DM (52.2 ± 9.3 years).

METHODS

and

MAIN OUTCOME MEASUREMENTS

Cardiometabolic profile, quality of life, and physical activity levels were assessed before and after 12 weeks of an aquatic-based exercise program.

RESULTS

The results show a significant improvement of cardiometabolic assessments (maximum oxygen consumption: 24.1 versus 21.1 mL/kg/min, P < .05; blood pressure: 125.4/77 versus 130.7/82.5 mm Hg, P < .05; fasting blood glucose: 119.6 versus 132.5 mg/dL, P < .05; body mass index: 29.9 versus 31.1 kg/m², P < .005; low-density lipoprotein cholesterol: 95.2 versus 104.9 mg/dL, P < .05; and diastolic function: E/E' 9.1 versus 10.1, P < .005) and an increase in quality of life and physical activity levels (Medical Outcome Study 36-item Short Form Health Survey mental component summary: 72.3 versus 67, P < .05; Problems Area About Diabetes: 20.1 versus 33.2, P < .005) and energy expenditure in general physical activity (physical activity: 3888.7 versus 1239.5 kcal/wk, P < .05).

CONCLUSIONS

These findings demonstrate that an aquatic-based exercise program produces benefits for the cardiovascular system and metabolic profile and appears to be safe and effective in improving quality of life and increasing physical activity levels in patients with 2DM.