Diabetes is associated with impaired myocardial performance in patients without significant coronary artery disease

Is Intrinsic Cardioprotection a Laboratory Phenomenon or a Clinically Relevant Tool to Salvage the Failing Heart?

Cardiovascular diseases, especially ischemic heart disease, as a leading cause of heart failure (HF) and mortality, will not reduce over the coming decades despite the progress in pharmacotherapy, interventional cardiology, and surgery. Although patients surviving acute myocardial infarction live longer, alteration of heart function will later lead to HF. Its rising incidence represents a danger, especially among the elderly, with data showing more unfavorable results among females than among males. Experiments revealed an infarct-sparing effect of ischemic "preconditioning" (IPC) as the most robust form of innate cardioprotection based on the heart's adaptation to moderate stress, increasing its resistance to severe insults. However, translation to clinical practice is limited by technical requirements and limited time. Novel forms of adaptive interventions, such as "remote" IPC, have already been applied in patients, albeit with different effectiveness. Cardiac ischemic tolerance can also be increased by other noninvasive approaches, such as adaptation to hypoxia- or exercise-induced preconditioning. Although their molecular mechanisms are not yet fully understood, some noninvasive modalities appear to be promising novel strategies for fighting HF through targeting its numerous mechanisms. In this review, we will discuss the molecular mechanisms of heart injury and repair, as well as interventions that have potential to be used in the treatment of patients.

Impact of diabetes in patients waiting for invasive cardiac procedures during COVID-19 pandemic

Background

During COVID-19 pandemic, elective invasive cardiac procedures (ICP) have been frequently cancelled or postponed. Consequences may be more evident in patients with diabetes.

Objectives

The objective was to identify the peculiarities of patients with DM among those in whom ICP were cancelled or postponed due to the COVID-19 pandemic, as well as to identify subgroups in which the influence of DM has higher impact on the clinical outcome.

Methods

We included 2,158 patients in whom an elective ICP was cancelled or postponed during COVID-19 pandemic in 37 hospitals in Spain. Among them, 700 (32.4%) were diabetics. Patients with and without diabetes were compared.

Results

Patients with diabetes were older and had a higher prevalence of other cardiovascular risk factors, previous cardiovascular history and co-morbidities. Diabetics had a higher mortality (3.0% vs. 1.0%; p = 0.001) and cardiovascular mortality (1.9% vs. 0.4%; p = 0.001). Differences were especially important in patients with valvular heart disease (mortality 6.9% vs 1.7% [p < 0.001] and cardiovascular mortality 4.9% vs 0.9% [p = 0.002] in patients with and without diabetes, respectively). In the multivariable analysis, diabetes remained as an independent risk factor both for overall and cardiovascular mortality. No significant interaction was found with other clinical variables.

Conclusion

Among patients in whom an elective invasive cardiac procedure is cancelled or postponed during COVID-19 pandemic, mortality and cardiovascular mortality is higher in patients with diabetes, irrespectively on other clinical conditions. These procedures should not be cancelled in patients with diabetes.

Contribution of Modern Echocardiographic Techniques in the Detection of Subclinical Heart Dysfunction in Young Adults with Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease affects about 30% of the population and it has a growing tendecy with the increasing incidence of obesity. Currently, a large amount of clinical evidence has shown that cardiovascular disease represents the main cause of mortality in patients suffering from non-alcoholic fatty liver disease.

OBJECTIVE

In this study we investigated the structural and functional changes of the left ventricle in young adults with hepatic steatosis using modern echocardiographic techniques.

METHODS

By using tissue Doppler imaging and also Speckle tracking echocardiography the left ventricle systolic function was assessed.

RESULTS

All patients included in the study had a normal left ventricular ejection fraction but, when the longitudinal function of the left ventricle was assessed using the tissue Doppler technique (maximum systolic velocity S) statistically significant differences were found in both the group of patients with non-alcoholic fatty liver as well as in the group of patients associated with diabetes. Using speckle tracking echocardiography, we found a statistically significant decrease of the global longitudinal strain in the endocardium, in the group of patients with non-alcoholic liver disease but also in the group of those with diabetes. The overall longitudinal strain at the myocardium was significantly reduced only in the group of patients with non-alcoholic fatty liver disease and diabetes, while the overall longitudinal strain at the epicardium showed no changes in any of the groups studied. Also, no changes were observed at the circumferential strain.

CONCLUSION

Non-alcoholic fatty liver disease, diagnosed in asymptomatic young adults may be a risk factor for remodeling the left ventricle over time, being associated with subclinical myocardial dysfunction, regardless of the presence of other cardiovascular risk factors.

Metabolomic signatures of cardiac remodelling and heart failure risk in the community

Aims

Heart failure (HF) is associated with several metabolic changes, but it is unknown whether distinct components of the circulating metabolome may be related to cardiac structure and function, and with incident HF in the community.

Methods and results

We assayed 217 circulating metabolites in 2336 Framingham Study participants (mean age 55 ± 10 years, 53% women) without HF at baseline. We used linear and Cox regression to relate concentrations of metabolites to left ventricular (LV) diastolic dimension, LV wall thickness, LV ejection fraction, left atrial dimension, LV ventricular mass, and aortic root size cross‐sectionally and to incident HF prospectively. Bonferroni‐adjusted P‐values <0.05 denoted statistical significance. Circulating concentrations of kynurenine [β = −0.12 cm per standard deviation (SD) increment in normalized residual of metabolite, P = 7.3 × 10⁻⁸] and aminoadipate (−0.11 cm per SD increment, P = 2.61 × 10⁻⁵) were associated with left ventricular diastolic dimension, phosphatidylcholine (carbon:double bound = 38:6) with left atrial dimension (0.10 cm per SD increment, P = 9.7 × 10⁻⁶), and cholesterol ester (carbon:double bound = 20:5) with left atrial dimension (0.10 cm per SD increment, P = 1.4 × 10⁻⁵) in multivariable‐adjusted models. During an average follow‐up of 15.8 (range 0.02–23.2) years, 113 participants (5%) were diagnosed with HF with reduced ejection fraction and 106 individuals (5%) with HF with preserved ejection fraction. In multivariable analyses, concentrations of phosphatidylcholine (hazard ratio 0.63, P = 1.3 × 10⁻⁵) and ornithine (hazard ratio 1.44, P = 0.00014) were associated with HF with reduced ejection fraction.

Conclusions

Several metabolites, including the vasoactive metabolite kynurenine, were related to cardiac structure and function in our sample. Additional research is warranted to confirm our observations and investigate if these metabolites can risk stratify ambulatory individuals.

Endothelial Dysfunction: A Contributor to Adverse Cardiovascular Remodeling and Heart Failure Development in Type 2 Diabetes beyond Accelerated Atherogenesis

Endothelial dysfunction, associated with depressed nitric oxide (NO) bioavailability, is awell-recognized contributor to both accelerated atherogenesis and microvascular complications intype 2 diabetes (DM). However, growing evidence points to the comorbidities-driven endothelialdysfunction within coronary microvessels as a key player responsible for left ventricular (LV)diastolic dysfunction, restrictive LV remodeling and heart failure with preserved ejection fraction(HFpEF), the most common form of heart failure in DM. In this review we have described: (1)multiple cellular pathways which may link depressed NO bioavailability to LV diastolicdysfunction and hypertrophy; (2) hemodynamic consequences and prognostic effects of restrictiveLV remodeling and combined diastolic and mild systolic LV dysfunction on cardiovascularoutcomes in DM and HFpEF, with a focus on the clinical relevance of endothelial dysfunction; (3)novel therapeutic strategies to improve endothelial function in DM. In summary, beyondassociations with accelerated atherogenesis and microvascular complications, endothelialdysfunction supplements the multiple interwoven pathways affecting cardiomyocytes, endothelialcells and the extracellular matrix with consequent LV dysfunction in DM patients. The associationamongst impaired endothelial function, reduced coronary flow reserve, combined LV diastolic anddiscrete systolic dysfunction, and low LV stroke volume and preload reserve-all of which areadverse outcome predictors-is a dangerous constellation of inter-related abnormalities, underlyingthe development of heart failure. Nevertheless, the relevance of endothelial effects of novel drugsin terms of their ability to attenuate cardiovascular remodeling and delay heart failure onset in DMpatients remains to be investigated.

The E/e' ratio difference between subjects with type 2 diabetes and controls. A meta-analysis of clinical studies

Type 2 diabetes is associated with an increased risk of heart failure. Left ventricular diastolic dysfunction and type 2 diabetes are frequently associated. Using echocardiography, we know that tissue Doppler imaging E/e’ ratio is a reliable predictor of left ventricular filling pressure. We performed a systematic review and meta-analysis to investigate the averaged E/e’ ratio value in patients with type 2 diabetes compared to non-diabetic controls. In the analysis we included cross-sectional studies providing the averaged E/e’ ratio. Subgroup/sensitivity analyses were conducted according to variables known to influence E/e’ ratio measurements. The analysis included 15 cross sectional studies with 877 type 2 diabetes patients and 1193 controls. The weighted mean difference showed higher values in diabetes (WMD 2.02; 95% CI 1.35, 2.70; p<0.001). The result was consistent in the subgroup/sensitivity analyses. Visual inspection of the funnel plot did not identify substantial asymmetry and the Egger test for funnel plot asymmetry showed a p value of 0.36. In conclusion, our assessment suggests that averaged E/e’ ratio is consistently increased in patients with type 2 diabetes compared to non-diabetic controls in the absence of cardiovascular diseases and complicated hypertension. This alteration may be a precocious diastolic alteration in the diabetic cardiomyopathy.

Global Longitudinal Strain at Rest for Detection of Coronary Artery Disease in Patients without Diabetes Mellitus

Global longitudinal strain (GLS) at rest on two-dimensional speckle tracking echocardiography (2D STE) was demonstrated to help detect coronary artery disease (CAD). However, the optimal cut-off point of GLS and its diagnostic power for detecting critical CAD in non-diabetes mellitus (DM) patients are unknown. In the present study, 211 patients with suspected CAD were prospectively included, with DM patients excluded. All patients underwent echocardiography and subsequently coronary angiography within 3 days. Left ventricular (LV) GLSs were quantified by 2D STE. Territorial peak systolic longitudinal strains (TLSs) were calculated based on the perfusion territories of the 3-epicardial coronary arteries in a 17-segment LV model. Critical CAD was defined as an area stenosis ≥70% in ≥1 epicardial coronary artery (≥50% in left main coronary artery). Totally 145 patients were diagnosed as having critical CAD by coronary angiography. Significant differences were observed in all strain parameters between patients with and without critical CAD. The area under the receiver operating charcteristic (ROC) curve (AUC) for GLS in the detection of left main (LM) or threevessel CAD was 0.875 at a cut-off value of -19.05% with sensitivity of 78.1% and specificity of 72.7%, which increased to 0.926 after exclusion of apical segments (cut-off value -18.66%; sensitivity 84.4% and specificity 81.8%). The values of TLSs were significantly lower in regions supplied by stenotic arteries than in those by non-stenotic arteries. The AUC for the TLSs to identify critical stenosis of left circumflex (LCX) artery, left anterior descending (LAD) artery and right coronary artery (RCA), in order of diagnostic accuracy, was 0.818 for LCX, 0.764 for LAD and 0.723 for RCA, respectively. In conclusion, in non-DM patients with suspected CAD, GLS assessed by 2D STE is an excellent predictor for LM or three-vessel CAD with high diagnostic accuracy, and a higher cut-off point than reported before should be used. Excluding apical segments in the calculation of GLS can further improve the predictive accuracy of GLS. It is unsatisfactory for TLSs to be used to identify stenotic coronary arteries.

[Stress dobutamine echocardiography or resting strain rate imaging to unveil an early symptomatic diabetic cardiomyopathy?]

Diabetes mellitus has been associated with changes in the structure and function of the myocardium manifesting in the early stages of the disease as subtle systolic and diastolic dysfunction; myocardial strain imaging has recently been favored over dobutamine stress echocardiography for early detection of diabetic cardiomyopathy. We report a case of an elderly diabetic patient presenting with pulmonary edema in whom at rest echocardiographic parameters including strain rate were all within normal range, while dobutamine stress echocardiography induced a deep systolic deterioration unmasking an early-stage diabetic cardiomyopathy.

Decreased regional left ventricular myocardial strain in type 1 diabetic children: a first sign of diabetic cardiomyopathy?

BACKGROUND AND OBJECTIVES

Type 1 diabetes is a major cardiovascular risk factor associated with an excess of mortality in young adults due to premature cardiovascular events, which includes heart failure. The relation between type 1 diabetes and cardiac structure and function in children was poorly documented. Our study investigates (1) whether type 1 diabetic children have echocardiographic signs of subclinical cardiac dysfunction assessed by tissue Doppler strain and (2) whether state of metabolic control and diabetes duration have any influence on the cardiac event.

METHODS

Standard echocardiography and tissue Doppler imaging were prospectively performed in type 1 diabetic children. Left ventricular dimensions, standard indices of systolic and diastolic function, and septal longitudinal strain were investigated.

RESULTS

Thirty consecutive asymptomatic diabetic children (age: 12.4 [5-17] years; males: 53%) were compared to 30 age and sex-matched healthy control subjects. Left ventricular mass index and diastolic septal thickness were significantly increased in diabetic children. There was no difference between two groups as regards the left ventricular ejection fraction and conventional mitral Doppler parameters (E, A, Ea). The global longitudinal systolic strain and strain rate were found to be decreased in children with diabetes. The global longitudinal early diastolic strain rate (Esr) was negatively correlated with metabolic control. Longitudinal strain was not correlated with diabetes duration.

CONCLUSION

Children with Type 1 diabetes had subclinical alterations in left ventricular size and longitudinal myocardial deformation.

Effect of crowding stress on tolerance to ischemia-reperfusion injury in young male and female hypertensive rats: molecular mechanisms

Sex and social stress may represent risk factors in the etiology of hypertension and heart response to ischemia-reperfusion (I/R) injury. Phosphatidylinositol 3-kinase/protein kinase B (Akt) plays an important role in the processes associated with hypertension and myocardial tolerance to I/R, and may be involved in myocardial stress reaction. The impact of chronic stress on the response to I/R was investigated in the hearts of 7-week-old spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats of both sexes. Stress was induced by reducing living space to 70 cm(2)/100 g body mass of rat for 2 weeks, while the controls were kept at 200 cm(2)/100 g. Langendorff-perfused hearts, subjected to I/R, exhibited higher vulnerability to ventricular tachycardia in crowd-stressed SHR vs. the control rats, and this was more pronounced in the males. Myocardial infarction was not affected by crowding stress in any of the groups. Male and female SHR showed increased activation of cardiac Akt, whereas nitric oxide synthase activity (NOS) with pro-apoptotic signaling decreased in the males but was not altered in the females (vs. WKY rats). NOS was enhanced in the female SHR and WKY groups by comparison with the respective males. Stress only reduced NOS activity in the SHR groups, and without changes in apoptotic markers. In conclusion, we showed that stress in young SHR mainly affects the nonlethal markers for I/R, and has no impact on myocardial infarction and apoptosis, despite reduced NOS activity.

Diagnostic power of longitudinal strain at rest for the detection of obstructive coronary artery disease in patients with type 2 diabetes mellitus

Global longitudinal strain (GLS) measured by 2-D speckle-tracking echocardiography (2-D STE) at rest has been recognized as a sensitive parameter in the detection of significant coronary artery disease (CAD). However, the diagnostic power of 2-D STE in the detection of significant CAD in patients with diabetes mellitus is unknown. Two-dimensional STE features were studied in total of 143 consecutive patients who underwent echocardiography and coronary angiography. Left ventricular global and segmental peak systolic longitudinal strains (PSLSs) were quantified by speckle-tracking imaging. In the presence of obstructive CAD (defined as stenosis ≥75%), global PSLS was significantly lower in patients with diabetes mellitus than in patients without (16.65 ± 2.29% vs. 17.32 ± 2.27%, p < 0.05). Receiver operating characteristic analysis revealed that global PSLS could effectively detect obstructive CAD in patients without diabetes mellitus (cutoff value: -18.35%, sensitivity: 78.8%, specificity: 77.5%). However, global PSLS could detect obstructive CAD in diabetic patients at a lower cutoff value with inadequate sensitivity and specificity (cutoff value: -17.15%; sensitivity: 61.1%, specificity: 52.9%). In addition, the results for segmental PSLS were similar to those for global PSLS. In conclusion, global and segmental PSLSs at rest were significantly lower in patients with both obstructive CAD and diabetes mellitus than in patients with obstructive CAD only; thus, PSLSs at rest might not be a useful parameter in the detection of obstructive CAD in patients with diabetes mellitus.

Evidence for a Specific Diabetic Cardiomyopathy: An Observational Retrospective Echocardiographic Study in 656 Asymptomatic Type 2 Diabetic Patients

Aim. Our aim was to assess the prevalence of subclinical diabetic cardiomyopathy, occurring among diabetic patients without hypertension or coronary artery disease (CAD). Methods. 656 asymptomatic patients with type 2 diabetes for 14 ± 8 years (359 men, 59.7 ± 8.7 years old, HbA1c 8.7 ± 2.1%) and at least one cardiovascular risk factor had a cardiac echography at rest, a stress cardiac scintigraphy to screen for silent myocardial ischemia (SMI), and, in case of SMI, a coronary angiography to screen for silent CAD. Results. SMI was diagnosed in 206 patients, and 71 of them had CAD. In the 157 patients without hypertension or CAD, left ventricular hypertrophy (LVH: 24.1%) was the most frequent abnormality, followed by left ventricular dilation (8.6%), hypokinesia (5.3%), and systolic dysfunction (3.8%). SMI was independently associated with hypokinesia (odds ratio 14.7 [2.7-81.7], p < 0.01) and systolic dysfunction (OR 114.6 [1.7-7907], p < 0.01), while HbA1c (OR 1.9 [1.1-3.2], p < 0.05) and body mass index (OR 1.6 [1.1-2.4], p < 0.05) were associated with systolic dysfunction. LVH was more prevalent among hypertensive patients and hypokinesia in the patients with CAD. Conclusion. In asymptomatic type 2 diabetic patients, diabetic cardiomyopathy is highly prevalent and is predominantly characterized by LVH. SMI, obesity, and poor glycemic control contribute to structural and functional LV abnormalities.

Association between type-2 diabetes mellitus and post-discharge outcomes in heart failure patients: findings from the RICA registry

AIMS

Heart failure (HF) and diabetes are common clinical conditions that may coexist. The main objective was to analyze the association of type-2 diabetes mellitus (T2DM) on prognosis in hospitalized patients with HF.

METHODS

We evaluated the association between T2DM with all-cause mortality and readmissions in the Spanish National Registry on Heart Failure-"Registro Nacional de Insuficiencia Cardiaca" (RICA). This is a multi-center and prospective cohort study that includes patients admitted for decompensated HF from 2008 to 2011. Study endpoints were all-cause mortality and hospital readmission. We determined the adjusted hazard ratio (HR) by a multivariable Cox regression model.

RESULTS

A total of 1082 patients (mean age 77.6±8.5) were included of whom 490 (45.3%) had diabetes and 592 patients (54.7%) had preserved left ventricular ejection fraction (LVEF). During one-year follow-up, 287 patients died (151 patients with diabetes) and 383 patients were readmitted (197 patients with diabetes). After adjusting for baseline characteristics T2DM was significantly associated with all-cause mortality (HR 1.54; 95%CI 1.20-1.97, p=0.001) and readmissions (HR 1.46; 95%CI 1.18-1.80, p<0.001). Age, dementia, peripheral vascular disease, NYHA class, renal insufficiency, hyponatremia and anemia were also independently associated with outcomes. There were no differences in mortality (p=0.415) and readmissions (p=0.514) according to preserved or reduced LVEF.

CONCLUSION

T2DM is very common in patients hospitalized for HF. This condition is a strong and independent co-morbidity of all-cause mortality and readmission for both HF with preserved and reduced LVEF.

Longitudinal left ventricular strain impairment in type 1 diabetes children and adolescents: a 2D speckle strain imaging study

AIM

Type 1 diabetes (T1D) involves complex metabolic disturbances in cardiomyocytes leading to morphological and functional abnormalities of the myocardium. The relationship between T1D and cardiac structure and function in children is not well established. Our study investigated whether T1D is associated with early subclinical myocardial disturbances in children and adolescents, and whether the state of metabolic control and diabetes duration are influential factors.

METHODS

Standard echocardiography, tissue Doppler imaging (TDI) and two-dimensional (2D) strain imaging were prospectively performed in 100 T1D children (age: 11.3 ± 3.6 years, 52 boys) and compared with 79 controls.

RESULTS

The diabetic and control children were comparable with respect to age, gender, heart rate and blood pressure. There were no significant differences between the two groups in left ventricular (LV) ejection fraction, LV remodelling and TDI parameters. Conventional mitral Doppler demonstrated significantly fewer diastolic filling abnormalities with an early filling wave in the diabetes group. Global longitudinal strain (GLS) was also significantly lower in the T1D children, while circumferential strain and radial strain did not differ. GLS correlated with HbA1c (r=0.52; P<0.01), but there was no correlation with diabetes duration.

CONCLUSION

Our results suggest that LV longitudinal myocardial deformation is decreased in young patients with T1D, and glycaemic control may be the main risk factor for these changes. Further follow-up is now necessary to precisely determine the clinical significance of these myocardial changes detected by 2D strain imaging in T1D children.

Prevalence and predictors of left ventricular diastolic dysfunction in a Hispanic patient population

Minimal data exist on attributes of diastolic dysfunction in the Hispanic population. The purpose of this study was to evaluate the prevalence and predictors of diastolic dysfunction in a Hispanic patient population. We performed a retrospective review of 166 consecutive echocardiograms in a southwestern Texas Hospital that caters to a large Hispanic patient population. We identified all echocardiograms that met criteria for diastolic dysfunction and assessed baseline demographics and comorbidities in the cohort of Hispanic patients. A multivariate analysis was performed to identify the independent predictors of diastolic dysfunction. A total of 129 out of 166 patients (77.8%) were of Hispanic origin. Out of the 129 patients, 87 (67.4%) had some degree of diastolic dysfunction in this population suggesting a high prevalence in the study cohort. In the diastolic dysfunction group, the mean age was 64.5 ± 13.9, 37% were male and 63% female, 78% had diabetes, 85% had hypertension, and 49% had some degree of renal insufficiency (stages 3-5). A logistic multivariate analysis showed that diabetes was an independent predictor of diastolic dysfunction with odds ratio of 2.69 (95% confidence interval [CI], 1.06-6.28; p = 0.038). Similarly age (per year increase) and chronic kidney disease were independent predictors of diastolic dysfunction. We demonstrated that older age, presence of diabetes, and renal dysfunction are independent predictors of diastolic dysfunction in the Hispanic patient population. Strategies geared toward reducing diabetes and preventing renal dysfunction are likely to decrease prevalence of diastolic dysfunction and heart failure in this community.

The increasing detection of asymptomatic left ventricular dysfunction in patients with type 2 diabetes mellitus without overt cardiac disease: data from the SHORTWAVE study

AIMS

Type 2 diabetes mellitus (DM) is associated with higher risk of heart failure. Over the last three decades several studies demonstrated the presence of asymptomatic systolic and/or diastolic left ventricular (LV) dysfunction (asymLVD) in patients with normal LV ejection fraction (LVEF). Purpose of our study was to assess the prevalence and factors associated with asymLVD in DM patients by echocardiographic indexes more sensitive than LVEF and transmitral flow detected by pulsed Doppler.

METHODS

386 DM patients without overt cardiac disease were enrolled from January to October 2011. Stress-corrected midwall shortening (sc-MS) and mitral annular peak systolic velocity (S') were considered as indexes of systolic function of circumferential and longitudinal myocardial fibers, respectively. Early diastolic velocity of transmitral flow was divided by early diastolic Tissue Doppler velocity of mitral annulus for identifying diastolic LVD.

RESULTS

asymLVD was detected in 262 patients (68%). 106 (27%) had isolated systolic asymLVD, 61 (16%) isolated diastolic asymLVD; in 95 (25%) systolic and diastolic asymLVD coexisted. Patients with asymLVD were older, had lower glomerular filtration rate, higher levels of glycated hemoglobin, C reactive protein, LV mass, relative wall thickness and prevalence of valve calcifications. Older age (HR 1.1 [1.02-1.18], p=0.01), aortic valve calcifications (HR 6.3 [1.31-30.31], p=0.02), LV concentric geometry defined as relative wall thickness ≥0.43 (HR 15.44 [2.96-80.44], p=0.001) were independent predictors of asymLVD at multivariate analysis.

CONCLUSIONS

Using suitable echocardiographic indexes, asymLVD is detectable in two/third of DM patients without overt cardiac disease and is predicted by older age, cardiac valve calcifications and LV concentric remodeling.

The impact of lifestyle-related risk factors on cardiac response to ischemia and possibilities to restore impaired ischemic tolerance

Risk factors (RF) of cardiovascular diseases associated with modern lifestyle, such as stress, chronically increased blood pressure, hyperglycemia and dyslipidemia have a negative impact on the heart exposed to ischemia: they may facilitate its lethal injury (myocardial infarction) and occurrence of sudden death due to ventricular arrhythmias. On the other hand, some stressful stimuli related to RF including reactive oxygen species, transient episodes of ischemia (hypoxia), high glucose and other may play a dual role in the pathogenesis of ischemia/reperfusion (I/R) injury (IRI). Besides their deleterious effects, these factors may trigger adaptive processes in the heart resulting in greater resistance against IRI, which is also a characteristic feature of the female myocardium. However, sensitivity to ischemia is increasing with age in both genders. Current research indicates that comorbidity related to lifestyle may impair the cardiac response to acute ischemia not only by interference with pathophysiological mechanisms of IRI per se, but via suppression of intrinsic protective mechanisms in the heart and its ability to tolerate the ischemic challenges, although the role of RF has not been unequivocally proven. Moreover, even pathologically altered myocardium need not completely lose its adaptive potential. In addition, increased ischemic tolerance can be induced by the pleiotropic (independent of the primary) effects of some hypolipidemic and antidiabetic drugs, even in the diseased myocardium. This review addresses the issue of the impact of RF on cellular cardioprotective mechanisms and the possibilities to restore adaptive potential in subjects challenged with several RF. Reactivation of adaptive processes in the myocardium taking into consideration gender and age can contribute to optimalization of antiischemic therapy.

New concept of myocardial longitudinal strain reserve assessed by a dipyridamole infusion using 2D-strain echocardiography: the impact of diabetes and age, and the prognostic value

AIMS

Although dipyridamole is a widely used pharmacological stress agent, the direct effects on myocardium are not entirely known. Diabetic cardiomyopathy can be investigated by 2D-strain echocardiography. The aim of this study was to assess myocardial functional reserve after dipyridamole infusion using speckle-tracking echocardiography.

METHODS

Seventy-five patients referred for dipyridamole stress myocardial perfusion gated SPECT (MPGS) were examined by echocardiography to assess a new concept of longitudinal strain reserve (LSR) and longitudinal strain rate reserve (LSRR) respectively defined by the differences of global longitudinal strain (GLS) and longitudinal strain rate between peak stress after dipyridamole and rest. Twelve patients with myocardial ischemia were excluded on the basis of MPGS as gold standard.

RESULTS

Mean LSR was -2.28±2.19% and was more important in the 28 (44%) diabetic patients (-3.27±1.93%; p=0.001). After multivariate analyses, only diabetes improved LSR (p=0.011) after dipyridamole infusion and was not associated with glycaemic control (p=0.21), insulin therapy (p=0.46) or duration of the disease (p=0.80). Conversely, age (p=0.002) remained associated with a decrease in LSR. LSSR was also correlated to age (p=0.005). Patients with a LSR<0% have a better survival after 15 months (log-rank p=0.0012).

CONCLUSION

LSR explored by 2D speckle-tracking echocardiography after dipyridamole infusion is a simple and new concept that provides new insights into the impact of diabetes and age on the myocardium with a potential prognostic value.

Poor glycaemic control and arrhythmias

OBJECTIVE

To evaluate number, type, and complexity of arrhythmias in diabetics compared with controls and, among diabetics, comparing good glycaemic control (GGC) and poor glycaemic control (PGC) patients.

METHODS

We compared Ambulatory Electrocardiogram recordings of 92 diabetics and 100 controls. The glycaemic profile of 50 diabetics, taken the same day as the Ambulatory ECG recording, was subdivided into GGC (gluco-stick mean values between 100 and 140 mg/dL) or PGC (gluco-stick values ≤99 mg/dL in 3-of-4 daily determination or gluco-stick values ≥140 mg/dL in 3-of-4 daily determination).

RESULTS

Diabetics show a higher prevalence of either ventricular ectopic beats (VEBs) (93.47% vs. 82% controls, p < 0.05) and heart rate (both in sinus rhythm and in atrial fibrillation) (98.35 ± 10 beats/min in diabetics vs. 78.10 ± 8.1 in controls, p < 0.001). Moreover, diabetics with PGC show either a higher prevalence of VEBs (96.42% vs 77.27% in GGC, p < 0.05) and of supraventricular ectopic beats (SVEBs) (96.42% vs. 68.18 in GGC, p < 0.05); furthermore, diabetics with PGC show more severe and complex atrial and ventricular arrhythmias (SVEBs 32.14% vs 0%, p < 0.05; VEBs 39.28% vs 9.09%, p < 0.05).

CONCLUSIONS

The analysis of our sample shows that the arrhythmogenic condition is not only provided from diabetic condition per se but it is enhanced in PGC. Infact PGC patients showed higher number of VEBs, often polymorphic, expression of more severe arrhythmic and cardiovascular outcome. This could be partially explained by hyperactivation of autonomic nervous system during metabolic stress (which increases mean heart rate). Moreover more severe diabetic patients may present coronary microangiopathy that can further explain their arrhythmogenic tendency.

Myocardial dysfunction in patients with type 2 diabetes mellitus: role of endothelial progenitor cells and oxidative stress

BACKGROUND

Endothelial progenitor cells (EPCs) are responsible for angiogenesis and maintenance of microvascular integrity, the number of EPCs is correlated with oxidative stress. Their relation to myocardial dysfunction in patients with type 2 diabetes mellitus (T2DM) is nonetheless unknown.

METHODS

Eighty-seven patients with T2DM and no history of coronary artery disease were recruited. Transthoracic echocardiography and detailed evaluation of left ventricular (LV) systolic function by 2-dimensional (2D) speckle tracking derived strain analysis in 3 orthogonal directions was performed. Four subpopulations of EPCs, including CD34+, CD133+, CD34+/kinase insert domain-containing receptor (KDR) + and CD133+/KDR + EPCs, were measured by flow cytometry. Oxidative stress was assessed by superoxide dismutase (SOD).

RESULTS

The mean age of the patients was 62 ± 9 years and 39.6% were male. Those with an impaired longitudinal strain had a lower number of CD34+ EPCs (2.82 ± 1.87% vs. 3.74 ± 2.12%, P < 0.05) than those with preserved longitudinal strain. When compared with those with preserved circumferential strain, patients with an impaired circumferential strain had a lower number of CD34+ EPCs (2.63 ± 1.80% vs. 3.87 ± 2.10%, P < 0.01) and SOD level (0.13 ± 0.06U/ml vs. 0.20 ± 0.08U/ml, P < 0.01). Patients with an impaired radial strain nonetheless had a lower number of CD34+ EPCs (2.62 ± 2.08% vs. 3.69 ± 1.99%, P < 0.05). Multivariate analysis demonstrated that only impaired global circumferential strain remained significantly associated with CD34 + EPCs and SOD.

CONCLUSIONS

LV global circumferential strain was independently associated with number of CD34+ EPCs and SOD. These findings suggest that myocardial dysfunction in patients with T2DM is related to depletion of EPCs and increased oxidative stress.

A new insight of mechanisms, diagnosis and treatment of diabetic cardiomyopathy

Diabetes mellitus is one of the most common chronic diseases across the world. Cardiovascular complication is the major morbidity and mortality among the diabetic patients. Diabetic cardiomyopathy, a new entity independent of coronary artery disease or hypertension, has been increasingly recognized by clinicians and epidemiologists. Cardiac dysfunction is the major characteristic of diabetic cardiomyopathy. For a better understanding of diabetic cardiomyopathy and necessary treatment strategy, several pathological mechanisms such as impaired calcium handling and increased oxidative stress, have been proposed through clinical and experimental observations. In this review, we will discuss the development of cardiac dysfunction, the mechanisms underlying diabetic cardiomyopathy, diagnostic methods, and treatment options.

Diabetic cardiomyopathy

Individuals with diabetes are at a significantly greater risk of developing cardioymyopathy and heart failure despite adjusting for concomitant risks such as coronary artery disease or hypertension. This has led to the increased recognition of a distinct disease process termed as "diabetic cardiomyopathy." In this article, we perform an extensive review of the pathogenesis and treatment of this disease. From a clinical perspective, physicians should be aware of this entity, and early screening should be considered because physical evidence of early diabetic cardiomyopathy could be difficult to detect. Early detection of the disease should prompt intensification of glycemic control, concomitant risk factors, use of pharmacologic agents such as β-blockers and renin-angiotensin-aldosterone system antagosists. From a research perspective, more studies on myocardial tissue from diabetic patients are needed. Clinical trials to evaluate the development of diabetic cardiomyopathy and fibrosis in early stages of the disease, as well as clinical trials of pharmacologic intervention in patients specifically with diabetic cardiomyopathy, need to be conducted.

Increased mortality in patients with conflicting diastolic parameters

The aim of this study was to describe the clinical characteristics and mortality of patients with conflicting diastolic function during follow-up. Up to 30% of patients have conflicting diastolic function by echo Doppler and therefore cannot be classified into a distinct diastolic dysfunction category of stage 1, 2 or 3. Using our established echocardiography data base, we studied a cohort of 250 subjects with conflicting diastolic function. Each individual was compared to two controls with normal diastolic and systolic function. The pre-specified goal of the analysis was a 6-year follow-up. Patients with conflicting diastolic function were more likely to have diabetes, hypertension, and established coronary artery disease. The Cox proportional hazards model determined that the risk of death was significantly higher for conflicting patients compared to patients with normal diastolic parameters (HR: 1.83; 95% CI: 1.32-2.53), P < 0.001. After adjustment for covariates, the risk of death remained elevated for the conflicting group (HR: 1.56; 95% CI: 1.11-2.18), P = 0.009. Conflicting diastolic dysfunction is associated with an increased risk of death compared to individuals with normal function. In conclusion, this emphasizes the need to attain a more precise characterization and categorization for patients with diastolic dysfunction.

Differential diagnosis and treatments of necrotizing otitis externa: a report of 19 cases

OBJECTIVE

Necrotizing otitis externa is an uncommon but potentially life-threatening infection disease of the external auditory canal and temporal bone. Its presentation and natural course had been largely altered through the years. The aim of this study was to analyze the clinical presentation, bacteriology, and treatment protocol and we compare those with the literature.

METHODS

A retrospective review of the archives of a tertiary referral center otolaryngology department (1995-2010) identified 19 cases of necrotizing otitis externa. The patient's epidemiologic, clinical, diagnostic and treatment data were evaluated.

RESULTS

A total of 19 patients were collected. Their mean age was 67.3 (SD, 12.2 year; range, 38-83 year). Of them, fourteen patients had diabetes mellitus (82.3%). The facial nerve was involved in 26% of the patients. Culture isolated Pseudomonas aeruginosa in 26.7% of cases, and half of them were resistant to ciprofloxacin. Five patients (26.3%) had temporomandibular area involvement. Eight patients received surgical intervention and all of them survived in the end of treatment course. The mean duration of hospitalization of was 25.8 ± 20.5 days (8-90). Two patients died during hospitalization, both from comorbidities (one from severe GI bleeding and another from septic shock).

CONCLUSION

The proportion of patients with facial palsy and diabetes in our series was comparable to those reported in the literature. But the incidence of P. aeruginosa was much lower and the rate of resistance to ciprofloxacin was high, which was supposed to result from the popularity and previous use of the quinolone ear drops before referral. And the leading cause of mortality is patient's comorbidities. Treating necrotizing otitis externa remains a great challenge even in nowadays with modern image modalities and advanced antibiotics. Physicians should have a high index of suspicion when facing patients at risk with refractory external ear infection so as to give them timely diagnosis and optimal treatment.

Prevalence and risk factors accounting for true silent myocardial ischemia: a pilot case-control study comparing type 2 diabetic with non-diabetic control subjects

Background

Given the elevated risk of cardiovascular events and the higher prevalence of silent coronary artery disease (CAD) in diabetic versus non-diabetic patients, the need to screen asymptomatic diabetic patients for CAD assumes increasing importante. The aims of the study were to assess prospectively the prevalence and risk factor predictors of true silent myocardial ischemia (myocardial perfusion defects in the absence of both angina and ST-segment depression) in asymptomatic type 2 diabetic patients.

Methods

Stress myocardial perfusion gated SPECT (Single Photon Emission Computed Tomography) was carried out in 41 type 2 diabetic patients without history of cardiovascular disease (CVD) and 41 nondiabetic patients matched by age and gender.

Results

There were no significant differences between the two groups regarding either the classic CVD risk factors or left ventricular function. True silent ischemia was detected in 21.9% of diabetic patients but only in 2.4% of controls (p < 0.01). The presence of myocardial perfusion defects was independently associated with male gender and the presence of diabetic retinopathy (DR). The probability of having myocardial perfusion defects in an asymptomatic diabetic patient with DR in comparison with diabetic patients without DR was 11.7 [IC95%: 3.7-37].

Conclusions

True silent myocardial ischemia is a high prevalent condition in asymptomatic type 2 diabetic patients. Male gender and the presence of DR are the risk factors related to its development.

Early diagnosis of left ventricular diastolic dysfunction in diabetic patients: a possible role for natriuretic peptides

Background

The aim of the present study was to verify whether BNP might detect pre-clinical diastolic dysfunction (LVDD) in type-2 diabetic patients.

Methods

One-hundred and twenty-seven consecutive outpatients with type-2 diabetes mellitus were enrolled into the study. Subjects with overt heart failure or NYHA class > 1, history of coronary artery disease, severe valvulopathy or chronic atrial fibrillation were excluded from the study. All patients underwent clinical evaluation, laboratory assessment of brain natriuretic peptide (BNP) and echocardiographic examination.

Results

No patients showed systolic impairment of left ventricular function, whereas diastolic dysfunction was detected in 53 (42%) cases (all impaired relaxation). Median BNP was 27 pg/ml without any significant difference between 76 patients with normal left ventricular function and 53 with diastolic dysfunction; in 54 (43%) patients showing HBA1C≥8 (uncontrolled diabetes) normal function was found in 32 and diastolic dysfunction in 22, with a significant difference of BNP at multivariate analysis (OR = 1.02, 95%CI = 1.05-1.09, p = 0.003). In uncontrolled diabetic cohort, BNP was a strong predictor for LVDD (OR = 2.7, 95%CI = 1.3-5.6, p = 0.006) along with the duration of diabetes (OR = 1.6, 95%CI = 1.1-2.9, p = 0.046). BNP > 25 pg/ml was a cut-off value with high accuracy to detect a LVDD.

Discussion

Early screening of high-risk patients for diabetic cardiomyopathy development might be useful to better control glycemic profile in order to reduce heart disease progression or even to reverse it

Conclusions

BNP could be a cheap, easy and useful tool to screen those ones with preclinical ventricular diastolic dysfunction in a subset of patients particularly prone to develop cardiovascular complications, like uncontrolled diabetic patients.

New and known type 2 diabetes as coronary heart disease equivalent: results from 7.6 year follow up in a Middle East population

Background

To investigate whether the known diabetes mellitus (KDM) or newly diagnosed diabetes mellitus (NDM) could be regarded as a coronary heart disease (CHD) risk equivalent among a relatively young Middle East population with high prevalence of diabetes mellitus (DM).

Methods

A population based cohort study of 2267 men and 2931 women, aged ≥ 30 years. Prior CHD was defined as self-reported or ECG positive CHD at baseline, KDM as subjects using any kind of glucose-lowering medications and NDM according to fasting plasma glucose and 2-h postchallenge glycemia.

Participants were categorized to six groups according to the presence of known or newly diagnosed DM and CHD at baseline (DM-/CHD-, DM-/CHD+, NDM+/CHD-, NDM+/CHD+, KDM+/CHD-, KDM+/CHD+) and Cox regression analysis were used to estimate the hazard ratio (HR) of CHD events for these DM/CHD groups, given DM-/CHD-as the reference.

Results

During 7.6-year follow up, 358 CHD events occurred. After controlling traditional risk factors, HRs of CHD events for DM-/CHD+ group were 2.1 (95% CI: 1.4-3.1) and 5.2 (3.2-8.3) in men and women respectively. Corresponding HRs for NDM+/CHD-were 1.7 (1.1-2.7) and 3.1 (1.8-5.6) and for KDM+/CHD-were 1.7 (0.9-3.3) and 6.2 (3.6-10.6) in men and women respectively. The HRs for NDM+/CHD+ and KDM+/CHD+ groups (i.e. participants with history of both diabetes and CHD) were 6.4 (3.2-12.9) and 8.0 (4.3-14.8) in women and 3.2 (1.9-5.6) and 4.2 (2.2-7.8) in men, respectively.

The hazard of CHD events did not differ between KDM+/CHD-and DM-/CHD+ in both genders using paired homogeneity test, however the HR for NDM+/CHD-was marginally lower than the HR for DM-/CHD+ in women (p = 0.085).

Conclusions

KDM patients in both genders and NDM especially in men exhibited a CHD risk comparable to nondiabetics with a prior CHD, furthermore diabetic subjects with prior CHD had the worst prognosis, by far more harmful in women than men; reinforcing the urgent need for intensive care and prophylactic treatment for cardiovascular diseases.

Metformin is associated with improved left ventricular diastolic function measured by tissue Doppler imaging in patients with diabetes

OBJECTIVE

To examine the association between selected glucose-lowering medications and left ventricular (LV) diastolic function in patients with diabetes.

DESIGN

Retrospective cohort study (years 2005-2008).

METHODS

Echocardiograms of 242 patients with diabetes undergoing coronary angiography were analyzed. All patients had an LV ejection fraction (LVEF) ≥20% and were without atrial fibrillation, bundle branch block, valvular disease, or cardiac pacemaker. Patients were grouped according to the use of metformin (n=56), sulfonylureas (n=43), insulin (n=61), and combination treatment (n=82).

RESULTS

Mean age (66±10 years) and mean LVEF (45±11%) were similar across the groups. Mean isovolumic relaxation time (IVRT) was 66±31, 79±42, 69±23, and 66±29 ms in metformin, sulfonylureas, insulin, and combination treatment groups respectively (P=0.4). Mean early diastolic longitudinal tissue velocity (e') was 5.3±1.6, 4.6±1.6, 5.3±1.8, and 5.4±1.7 cm/s in metformin, sulfonylureas, insulin, and combination treatment groups (P=0.04). In adjusted linear regression models, the use of metformin was associated with a shorter IVRT (parameter estimate -9.9 ms, P=0.049) and higher e' (parameter estimate +0.52 cm/s, P=0.03), compared with no use of metformin. The effects of metformin were not altered by concomitant use of sulfonylureas or insulin (P for interactions >0.4).

CONCLUSIONS

The use of metformin is associated with improved LV relaxation, as compared with no use of metformin.

Chromosome 9p21.3 polymorphism in a Chinese Han population is associated with angiographic coronary plaque progression in non-diabetic but not in type 2 diabetic patients

BACKGROUND

We sought to explore the association of variant rs1333049 on chromosome 9p21.3 with coronary artery disease (CAD) and angiographic plaque progression in non-diabetic and type 2 diabetic patients.

METHODS

Genotyping and quantitative coronary angiography (QCA) were performed in 2046 Chinese Han patients (1012 diabetic cases) undergoing coronary angiography; 430 of them received repeat angiographic studies at 1-year follow-up.

RESULTS

CC genotype at rs1333049 on chromosome 9p21.3 was associated with CAD (unadjusted OR 1.524, p = 0.001 and adjusted OR 1.859, p = 0.005, respectively). However, CC genotype had no magnified association with CAD in diabetic patients (OR 1.275, p = 0.150) compared with non-diabetic counterparts (OR 1.446, p = 0.020) after adjusting for conventional risk factors. During angiographic follow-up, non-diabetic patients (n = 280) had significant decrease in minimal lumen diameter and increase in percent diameter stenosis among the three genotypes (p = 0.005 and p = 0.038, respectively), demonstrating that CC or GC genotype carriers had a more severe plaque progression than GG genotype carriers. In patients with type 2 diabetes (n = 150), although plaque progression was more severe than that in non-diabetic counterparts, no relations existed between plaque progression and genotypes. Rs1333049 was an independent determinant of plaque progression for non-diabetic (OR 3.468, p = 0.004 and OR 4.339, p = 0.002 for GC and CC genotype, respectively) but not for diabetic patients (OR 0.529, p = 0.077 and 0R 0.878, p = 0.644 for GC and CC genotype, respectively).

CONCLUSIONS

This study demonstrates a significant association of homozygous CC genotype of rs1333049 on chromosome 9p21.3 with CAD in Chinese Han population. Rs1333049 polymorphism is an independent determinant for coronary plaque progression in non-diabetic but not in type 2 diabetic patients.