Left ventricular diastolic dysfunction in diabetic patients: pathophysiology and therapeutic implications

Evaluation of the relationship between left atrial stiffness, left ventricular stiffness, and left atrioventricular coupling index in type 2 diabetes patients: a speckle tracking echocardiography study

Background

Cardiovascular complications are a leading cause of mortality and disability in individuals with diabetes mellitus (DM). Moreover, DM can directly impact the structure and function of cardiac muscle. We conducted a study to evaluate cardiac stiffness in DM patients in both the left atrium (LA) and left ventricle (LV), as well as to assess the impact of DM on the synchronization of the LA and LV, particularly within the Vietnamese population, utilizing speckle tracking echocardiography (STE).

Methods

We studied 111 research subjects divided into two groups comprising 52 patients with DM and 59 healthy individuals. All the subjects provided relevant clinical information, and echocardiography was performed to assess the indices of LA stiffness, LV stiffness, and left atrioventricular coupling index (LACI).

Results

Our study indicated that DM patients exhibited greater LA and LV stiffness than control patients. The LACI (%) in the DM group was also greater than that in the control group (17.12% ± 6.72% vs. 12.28% ± 3.96%, respectively; p < 0.001). The LACI was positively correlated with the LA and LV stiffness indices. Decreased levels of LV GLS, adjusted for age, sex, blood pressure, and BMI, have emerged as identified risk factors for DM.

Conclusions

LA stiffness, LV stiffness, and the LACI are greater in DM patients than in normal individuals.

Assessment of subclinical left ventricular systolic and diastolic dysfunction in patients with type 2 diabetes mellitus under follow-up at Tikur Anbessa specialized hospital, Ethiopia: a case-control study

BACKGROUND

Individuals with diabetes mellitus are at increased risk of cardiovascular diseases, which in turn are the most common cause of morbidity and mortality in the diabetic population. A peculiar feature of cardiovascular diseases in this population is that they can have significant cardiac disease while remaining asymptomatic. There is a paucity of data regarding subclinical cardiac imaging features among diabetic adults in Africa, particularly in Ethiopia. This study was conducted to compare the magnitude and spectrum of left ventricular systolic and diastolic dysfunction among asymptomatic type 2 diabetic adults versus a normotensive, non-diabetic control group and to evaluate the determinants of left ventricular diastolic and systolic dysfunction.

METHODS

This was a case-control study conducted at Tikur Anbessa specialized hospital, Addis Ababa, Ethiopia. A standard transthoracic echocardiography was done for all study participants with type 2 diabetes mellitus and their normotensive and non-diabetic controls. Structured questionnaires were used to collect demographic and clinical characteristics and laboratory test results. Statistical analysis was done using the SPSS 25.0 software. The data was summarized using descriptive statistics. Bivariate and multivariate analysis was performed to determine the association between variables and echocardiographic parameters. The strength of statistical association was measured by adjusted odds ratios and 95% confidence intervals, with significant differences taken at p < 0.05.

RESULTS

We analyzed age- and sex-matched 100 participants in the study (diabetic) group and 200 individuals in the control group. Left ventricular systolic and diastolic dysfunction were significantly more prevalent among diabetic adults than their sex and age matched controls. Among diabetic individuals, ages of 60 years and above, dyslipidemia, use of Metformin and Glibenclamide, high serum triglyceride level, presence of neuropathy and use of statins correlated significantly with the presence of left ventricular diastolic dysfunction. Chronic kidney disease and neuropathy were determinants of left ventricular systolic dysfunction.

CONCLUSION

Left ventricular systolic and diastolic dysfunction were significantly more prevalent among diabetic patients than their sex- and age-matched controls in our study. We recommend early screening for subclinical left ventricular dysfunction, especially in the elderly and in those with chronic kidney disease, dyslipidemia, and microvascular complications such as neuropathy.

A genetic mouse model of lean-NAFLD unveils sexual dimorphism in the liver-heart axis

Lean patients with NAFLD may develop cardiac complications independently of pre-existent metabolic disruptions and comorbidities. To address the underlying mechanisms independent of the development of obesity, we used a murine model of hepatic mitochondrial deficiency. The liver-heart axis was studied as these mice develop microvesicular steatosis without obesity. Our results unveil a sex-dependent phenotypic remodeling beyond liver damage. Males, more than females, show fasting hypoglycemia and increased insulin sensitivity. They exhibit diastolic dysfunction, remodeling of the circulating lipoproteins and cardiac lipidome. Conversely, females do not manifest cardiac dysfunction but exhibit cardiometabolic impairments supported by impaired mitochondrial integrity and β-oxidation, remodeling of circulating lipoproteins and intracardiac accumulation of deleterious triglycerides. This study underscores metabolic defects in the liver resulting in significant sex-dependent cardiac abnormalities independent of obesity. This experimental model may prove useful to better understand the sex-related variability, notably in the heart, involved in the progression of lean-NAFLD.

Prevalence of cardiac abnormalities and heart failure in unselected out-patients with type 2 diabetes mellitus and associated clinical factors: Real-world evidence from an Indian registry

OBJECTIVE

Type 2 diabetes mellitus (T2DM) is known to be associated with development of left ventricular (LV) dysfunction and heart failure (HF). The study aimed to determine the prevalence of LV dysfunction and HF in unselected out-patients with T2DM with no previous cardiac history and to correlate LV dysfunction and HF with demographic and comorbid characteristics.

METHODS

This cross-sectional study conducted at 27 centers in India captured demographic and clinical data through electronic case record forms. B-type natriuretic peptide of >105 pg/mL was used to diagnose HF and two-dimensional echocardiography was used to assess LV dysfunction.

RESULTS

Of the 615 patients, 54.3 % (n = 334) were males; mean age was 57.4 ± 10.48 years. More than one-third of the patients had T2DM duration of >10 years (n = 238; 38.7 %), with hypertension as the most prevalent comorbidity (n = 372, 78.6 %). Approximately 61.3 % of the patients had LV hypertrophy. The mean LV mass was 135.0 ± 56.16 g (95 % CI 130.28, 139.70). The prevalence of any type of LV dysfunction, including systolic or diastolic dysfunction and HF was 55 % (95 % CI 51.0, 59.0) and 10 % (95 % CI 7.0, 12.0), respectively. A negligible but statistically significant correlation was observed between LV dysfunction and T2DM duration (p = 0.011), alongside HF and age (p < 0.0001).

CONCLUSION

Real-world data from this registry from India demonstrates a substantial burden of LV dysfunction and HF in individuals with T2DM in India. It is imperative to formulate strategies for early identification of LV dysfunction in individuals with T2DM for prevention and consequent management of HF.

The Relationship of Left Ventricular Diastolic Dysfunction and Asymmetrical Dimethylarginine as a Biomarker of Endothelial Dysfunction with Cardiovascular Risk Assessed by Systematic Coronary Risk Evaluation2 Algorithm and Heart Failure-A Cross-Sectional Study

Background: Cardiovascular (CV) risk factors, causing endothelial dysfunction (ED) and left ventricular diastolic dysfunction (LVDD), contribute to an increased risk of heart failure (HF). The aim of this study was to determine the relationship between the occurrence of LVDD and ED with CV risk assessed by the Systematic Coronary Risk Evaluation2 (SCORE2) algorithm and HF. Methods: In the period from November 2019 to May 2022, a cross-sectional study that included 178 middle-aged adults was conducted. Transthoracic echocardiography (TTE) was used to assess left ventricular (LV) diastolic and systolic function. ED was assessed using the plasma values of asymmetric dimethylarginine (ADMA) and was determined using the ELISA method. Results: The majority of subjects with LVDD grades 2 and 3 had high/very high SCORE2, developed HF and all were taking medication (p < 0.001). They also had significantly lowest plasma ADMA values (p < 0.001). We found that the reduction of ADMA concentration is influenced by certain groups of drugs, or more significantly, by their combinations (p < 0.001). Conclusions: In our study, we confirmed a positive correlation between LVDD, HF and SCORE2 severity. The results showed a negative correlation between the biomarkers of ED, LVDD severity, HF, and SCORE2, which we believe is due to medication effects.

Daidzein mitigates myocardial injury in streptozotocin-induced diabetes in rats

AIM

Present study focuses on the effect of daidzein in an experimental model of diabetic cardiomyopathy in rats.

MATERIALS AND METHODS

Diabetes was induced in male Sprague Dawley rats by a single intraperitoneal injection of STZ at dose 55 mg/kg. Daidzein treatment was started after six weeks of diabetes induction. Animals received daidzein at a dose of 25, 50, and 100 mg/kg orally for the next four weeks.

KEY FINDINGS

Diabetic control animals showed significant prolongation in QT interval, PR interval, and R wave amplitude as compared to normal control animals. Treatment with daidzein at dose 100 mg/kg significantly normalized the QT interval, PR interval, and R wave amplitude. A significant reduction in QRS duration was observed in diabetic animals. Treatment with daidzein significantly improved the QRS duration after treatment. Hemodynamic parameters like systolic pressure (SBP), diastolic pressure (DBP) and mean atrial pressure (MAP) were found to be significantly decreased in diabetic animals. Treatment with daidzein at dose 100 mg/kg significantly improved the SBP, DBP, and MAP. Daidzein treatment prevented the loss of cardiac marker enzyme from heart tissue and also increased the level of AMPK and SIRT1 in plasma. Protein expression of NOX-4 and RAC-1 was also found to be reduced in cardiac tissue of daidzein treated animals. Daidzein treatment improved oxidative defense mechanism and reduced cardiac tissue necrosis and fibrosis.

SIGNIFICANCE

From the results, it can be concluded that daidzein mitigates the progression of diabetic cardiomyopathy by inhibiting NOX-4 induced oxidative stress in cardiac tissue.

Understanding the association between endothelial dysfunction and left ventricle diastolic dysfunction in development of coronary artery disease and heart failure

Cardiovascular diseases (CVDs)  have been the most common cause of death worldwide for decades. Until recently the most affected patients were middle-aged and elderly, predominantly men, with more frequent ST elevation myocardial infarction  (STEMI) caused by obstructive coronary artery disease (CAD). However, in the last two decades we have noticed an increased incidence of ischemia with non-obstructive coronary arteries (INOCA), which includes myocardial infarction with non-obstructive coronary arteries (MINOCA) and non-myocardial infarction syndromes, such as microvascular and vasospastic angina, conditions that have been particularly pronounced in women and young adults - the population we considered low-risky till than. Therefore, it has become apparent that for this group of patients conventional methods of assessing the risk of future cardiovascular (CV) events are no longer specific and sensitive enough. Heart failure with preserved ejection fraction (HFpEF) is another disease, the incidence of which has been rising rapidly during last two decades, and predominantly affects elderly population. Although the etiology and pathophysiology of INOCA and HFpEF are complex and not fully understood, there is no doubt that the underlying cause of both conditions is endothelial dysfunction (ED) which further promotes the development of left ventricular diastolic dysfunction (LVDD). Plasma biomarkers of ED, as well as natriuretic peptides (NPs), have been intensively investigated recently, and some of them have great potential for early detection and better assessment of CV risk in the future.

Echocardiographic Changes in Newly Diagnosed Type 2 Diabetes Mellitus Patients with and without Hypertension

Background

Whether type 2 diabetes mellitus (T2DM) is independently associated with structural heart abnormalities is controversial because of confounders associated with T2DM. This study aimed to investigate echocardiographic features in patients with newly diagnosed T2DM, exploring changes in cardiac structure and function.

Material/Methods

This was a retrospective study of new T2DM cases treated at the Second People’s Hospital Affiliated to Nanjing Medical University (Changzhou) in 2014–2016. In all, 128 T2DM cases were included (62 hypertensive and 66 non-hypertensive individuals). Controls were selected among individuals who underwent examination at the same department/period. Interventricular septal thickness (IVST), left ventricular end-diastolic diameter (LVEDD), posterior left ventricular wall thickness (PWTD), left ventricle mass (LVM), end-diastolic thickness of left ventricular posterior wall (Dd), aortic root diameter, left atrial diameter (LAd), left atrial diameter fraction-shortening values, and left ventricular ejection fraction (LVEF) were determined routinely.

Results

IVST, LVEDD, PWTD, Dd, LAd, and left atrial diameter fraction-shortening values were larger in patients with T2DM (all P<0.05 vs. controls). LVM was higher in T2DM patients (median, 57.12 vs. 54.77 g, P=0.001). There were no differences in aortic root diameter and EF (both P>0.05). Multivariable analysis showed that IVST (OR=1.33, 95% CI: 1.01–1.76, P=0.04), LAd (OR=1.16, 95% CI: 1.07–1.25, P<0.001), TGs (OR=1.34, 95% CI: 1.09–1.63, P=0.005), and HDL (OR=1.46, 95% CI: 1.02–2.08, P=0.04) were independently associated with hypertension in patients with T2DM.

Conclusions

Patients with newly diagnosed T2DM already display structural heart abnormalities. LAd and IVST are independently associated with hypertension in these patients, probably contributing to increased cardiovascular risk.

A dipeptidyl peptidase-IV inhibitor improves diastolic dysfunction in Dahl salt-sensitive rats

To date, there is no established treatment for heart failure with preserved ejection fraction (HFpEF). Dipeptidyl peptidase-IV (DPP-IV) inhibitors reportedly have improved not only diabetes mellitus but also heart failure with systolic dysfunction in experimental models. We investigated the effects of a DPP-IV inhibitor on HFpEF in rats. Dahl salt-sensitive rats were fed either high-salt (high-salt diet (HSD): 8% NaCl) or low-salt diets (0.3% NaCl) from 6.5 weeks of age. They were then treated with or without a DPP-IV inhibitor, vildagliptin (10 mg/kg/day, orally), from 11 weeks of age for 9 weeks and analyzed at the age of 20 weeks. HSD rats mimicked the pathophysiology of HFpEF. There were no differences in heart rate, blood pressure, left ventricular (LV) systolic function, or the extent of LV hypertrophy between HSD rats with or without vildagliptin. However, vildagliptin decreased LV end-diastolic pressure, the most reliable hemodynamic parameter of HFpEF in HSD rats. Vildagliptin also decreased the LV distensibility index, a sensitive marker of LV diastolic function in HSD rats. Vildagliptin decreased the expression of collagen genes in HSD hearts and attenuated LV interstitial fibrosis (HSD with vehicle and vildagliptin, 2.9% vs. 1.9%; P < 0.05). Furthermore, vildagliptin administration reduced both plasma renin activity and aldosterone concentrations in HSD rats. A DPP-IV inhibitor, vildagliptin, improved the severity of LV fibrosis, and thus, diastolic dysfunction of HFpEF in Dahl salt-sensitive hypertensive rats. DPP-IV inhibitors are promising medicines for treatment of HFpEF in patients with diabetes mellitus.

Impact of glycemic control on aortic stiffness, left ventricular mass and diastolic longitudinal function in type 2 diabetes mellitus

BACKGROUND

Poor glycemic control is associated with impaired left ventricular (LV) diastolic function in patients with type 2 diabetes mellitus (T2DM). Inappropriate LV mass increase and accelerated aortic stiffening were suggested to participate on deterioration of diastolic function. The present study investigated the inter-relationships between glycemic control, early diastolic and systolic longitudinal velocity of mitral annulus, LV mass and aortic stiffness in T2DM patients free of cardiovascular disease and with preserved LV ejection fraction, and compared them with those observed in healthy volunteers of similar age and sex distribution.

METHODS

125 T2DM patients and 101 healthy volunteers underwent noninvasive measurement of systolic (s') and early diastolic (e') velocities of mitral annulus, LV mass, carotid-femoral pulse wave velocity (cfPWV) and local carotid blood pressure (BP).

RESULTS

Forty-four (35.2%) T2DM patients had e' velocity lower than that expected for age (against 7.9% in healthy volunteers; P < 0.0001), 34 (27.2%) had cfPWV higher than that expected for age and mean BP (against 5.9% in healthy volunteers; P < 0.0001), and 71 (56.8%) had LV mass higher than that expected for body size and stroke work (against 17.6% in healthy volunteers; P < 0.0001). Carotid systolic BP was higher in T2DM patients (124 ± 14 vs 111 ± 11 mmHg; P < 0.0001). In multivariate analysis, e' velocity was independently related to age, carotid BP and s' velocity in healthy volunteers, and to male sex, age, carotid BP, heart rate and LV mass in T2DM. Glycosylated hemoglobin (HbA1c) was independently related to cfPWV and LV mass in T2DM patients. T2DM patients with HbA1c ≥6.5% (N = 85) had higher cfPWV (P < 0.05), central BP (P = 0.01), prevalence of LV hypertrophy (P = 0.01) and lower e' and s' velocity (P = 0.001 and <0.05, respectively) as compared to those with HbA1c <6.5%.

CONCLUSIONS

One-third of T2DM patients with preserved LV ejection fraction has sign of subclinical LV diastolic dysfunction. HbA1c levels are positively associated with LV mass and aortic stiffness, both of which show a negative independent impact on early diastolic velocity e', the latter through an increase in afterload. T2DM patients with suboptimal glycemic control (HbA1c ≥ 6.5%) have lower diastolic and systolic LV longitudinal performance, together with increased aortic stiffness and a higher prevalence of LV hypertrophy.

Selective Heart Rate Reduction Improves Metabolic Syndrome-related Left Ventricular Diastolic Dysfunction

BACKGROUND

Enhanced heart rate observed in metabolic syndrome (MS) contributes to the deterioration of left ventricular (LV) function via impaired LV filling and relaxation, increased myocardial O2 consumption, and reduced coronary perfusion. However, whether heart rate reduction (HRR) opposes LV dysfunction observed in MS is unknown.

METHODS

We assessed in Zucker fa/fa rats, a rat model of MS, the cardiovascular effects of HRR induced by the If current inhibitor S38844 (3 mg · kg(-1) · d(-1)).

RESULTS

Delayed short-term (4 days) and long-term (90 days) HRR induced by S38844 reduced LV end-diastolic pressure and LV end-diastolic pressure-volume relation, increased myocardial tissue perfusion, decreased myocardial oxidized glutathione levels, and preserved cardiac output, without modifying LV end-systolic pressure and LV end-systolic pressure-volume relation, although only long-term S38844 opposed LV collagen accumulation. Long-term S38844 improved flow-induced endothelium-dependent dilatation of mesenteric arteries, while metabolic parameters, such as plasma glucose levels, and Hb1c, were never modified.

CONCLUSIONS

In rats with MS, HRR induced by the If inhibitor S38844 improved LV diastolic function and endothelium-dependent vascular dilatation, independent from modifications in metabolic status. Moreover, this improvement in cardiac function involves not only immediate effects such as improved myocardial perfusion and reduced oxidative stress but also long-term effects such as modifications in the myocardial structure.

Present Insights on Cardiomyopathy in Diabetic Patients

The pathogenesis of diabetic cardiomyopathy (DCM) is partially understood and is likely to be multifactorial, involving metabolic disturbances, hypertension and cardiovascular autonomic neuropathy (CAN). Therefore, an important need remains to further delineate the basic mechanisms of diabetic cardiomyopathy and to apply them to daily clinical practice. We attempt to detail some of these underlying mechanisms, focusing in the clinical features and management. The novelty of this review is the role of CAN and reduction of blood pressure descent during sleep in the development of DCM. Evidence has suggested that CAN might precede left ventricular hypertrophy and diastolic dysfunction in normotensive patients with type 2 diabetes, serving as an early marker for the evaluation of preclinical cardiac abnormalities. Additionally, a prospective study demonstrated that an elevation of nocturnal systolic blood pressure and a loss of nocturnal blood pressure fall might precede the onset of abnormal albuminuria and cardiovascular events in hypertensive normoalbuminuric patients with type 2 diabetes. Therefore, existing microalbuminuria could imply the presence of myocardium abnormalities. Considering that DCM could be asymptomatic for a long period and progress to irreversible cardiac damage, early recognition and treatment of the preclinical cardiac abnormalities are essential to avoid severe cardiovascular outcomes. In this sense, we recommend that all type 2 diabetic patients, especially those with microalbuminuria, should be regularly submitted to CAN tests, Ambulatory Blood Pressure Monitoring and echocardiography, and treated for any abnormalities in these tests in the attempt of reducing cardiovascular morbidity and mortality.

A meta-analysis of the therapeutic effects of glucagon-like Peptide-1 agonist in heart failure

We conducted a meta-analysis of the existing literature of the therapeutic effects of using GLP-1 agonists to improve the metabolism of the failing heart. Animal studies showed significant improvement in markers of cardiac function, such as left ventricular ejection fraction (LVEF), with regular GLP-1 agonist infusions. In clinical trials, the potential effects of GLP-1 agonists in improving cardiac function were modest: LVEF improved by 4.4% compared to placebo (95% C.I 1.36–7.44, P = 0.005). However, BNP levels were not significantly altered by GLP-1 agonists in heart failure. In two trials, a modest increase in heart rate by up to 7 beats per minute was noted, but meta-analysis demonstrated this was not significant statistically. The small number of studies plus variation in the concentration and length of the regime between the trials would limit our conclusions, even though statistically, heterogeneity chi-squared tests did not reveal any significant heterogeneity in the endpoints tested. Moreover, studies in non-diabetics with heart failure yielded conflicting results. In conclusion, the use of GLP-1 agonists has at best a modest effect on ejection fraction improvement in heart failure, but there was no significant improvement in BNP levels in the meta-analysis.

The association between left ventricular diastolic function and a mild-to-moderate decrease in glomerular filtration rate in patients with type 2 diabetes mellitus

This prospective study evaluated the relationship between echocardiography parameters of left ventricular (LV) diastolic function and mild-to-moderate renal function impairment in 82 patients with type 2 diabetes mellitus. The mean age of the patients was 61.1 years. A significant correlation was found between estimated glomerular filtration rate (eGFR) and the ratio of peak velocity of early transmitral flow (E) to peak velocity of early diastolic mitral annular motion (E'). Cluster analysis revealed two subgroups of patients with different E' values but comparable eGFRs. The correlation between eGFR and E/E' was significant in 38 patients with E' ≤ 7.1 cm/s, but not significant in 44 patients with E' > 7.1 cm/s. The results suggest that the deterioration of LV relaxation (E') represents the underlying condition for the association between mild-to-moderate renal function impairment and the non-invasive parameter of LV end-diastolic pressure (E/E'), in patients with type 2 diabetes without any previous cardiovascular event and with well-controlled blood pressure.

Cardiac contractile dysfunction and apoptosis in streptozotocin-induced diabetic rats are ameliorated by garlic oil supplementation

Previous studies have suggested that garlic oil could protect the cardiovascular system. However, the mechanism by which garlic oil protects diabetes-induced cardiomyopathy is unclear. In this study, streptozotocin (STZ)-induced diabetic rats received garlic oil (0, 10, 50, or 100 mg/kg of body weight) by gastric gavage every 2 days for 16 days. Normal rats without diabetes were used as control. Cardiac contractile dysfunction examined by echocardiography and apoptosis evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay were observed in diabetic rat hearts. Additionally, a shift in cardiac myosin heavy chain (MHC) gene expression from α- to β-MHC isoform, decreased levels of superoxide dismutase-1 (SOD-1) and cardiac α-actin, and elevated cardiac thiobarbituric acid reactive substances (TBARS) and caspase- and p38-NFκB-leading apoptosis signaling activities were demonstrated in diabetic hearts. However, these diabetes-related cardiac dysfunctions were almost dose-dependently ameliorated by garlic oil administration. In conclusion, garlic oil possesses significant potential for protecting hearts from diabetes-induced cardiomyopathy.

Long-term outcome after thrombectomy in acute myocardial infarction

BACKGROUND

Current data appear in favour of thrombectomy for ST-elevation myocardial infarction (STEMI). However, information on long-term outcome after thrombectomy is limited. We performed a retrospective long-term study to assess the risk of cardiac re-hospitalizations and survival after discharge from the index hospitalization for STEMI.

METHODS

Patients originally randomized to percutaneous coronary intervention (PCI) with thrombectomy vs. standard PCI were included in a retrospective long-term observational study. The primary study endpoint was the combined risk for all-cause death or cardiac re-hospitalization after index discharge under optimal medical therapy. The cumulative number of cardiac hospitalization days and ventricular remodelling assessed by echocardiography and plasma biomarkers were secondary endpoints.

RESULTS

Of 94 STEMI patients who had been randomized between 11/2000 and 03/2003, 89 patients consented to long-term follow-up. A total of 43 patients had been allocated to thrombectomy and 46 to standard primary PCI. The minimum follow-up time was 1115 days. There was a significantly lower risk for death or cardiac re-hospitalization for patients of the thrombectomy group (hazard ratio = 0.69, 95% CI: 0.49-0.98, P = 0.036). The incidence of recurrent myocardial infarction was not different (P = 0.343). No differences in cardiac remodelling were detected by echocardiography, with the exception that heart-type fatty acid binding protein at 53.2 +/- 17 months was lower in the thrombectomy group (P = 0.045).

CONCLUSION

Thrombectomy in STEMI may decrease the long-term risk for death or cardiac re-hospitalization.

Cardiac remodeling in obesity

The dramatic increase in the prevalence of obesity and its strong association with cardiovascular disease have resulted in unprecedented interest in understanding the effects of obesity on the cardiovascular system. A consistent, but puzzling clinical observation is that obesity confers an increased susceptibility to the development of cardiac disease, while at the same time affording protection against subsequent mortality (termed the obesity paradox). In this review we focus on evidence available from human and animal model studies and summarize the ways in which obesity can influence structure and function of the heart. We also review current hypotheses regarding mechanisms linking obesity and various aspects of cardiac remodeling. There is currently great interest in the role of adipokines, factors secreted from adipose tissue, and their role in the numerous cardiovascular complications of obesity. Here we focus on the role of leptin and the emerging promise of adiponectin as a cardioprotective agent. The challenge of understanding the association between obesity and heart failure is complicated by the multifaceted interplay between various hemodynamic, metabolic, and other physiological factors that ultimately impact the myocardium. Furthermore, the end result of obesity-associated changes in the myocardial structure and function may vary at distinct stages in the progression of remodeling, may depend on the individual pathophysiology of heart failure, and may even remain undetected for decades before clinical manifestation. Here we summarize our current knowledge of this complex yet intriguing topic.

Beneficial effects of rosiglitazone on novel cardiovascular risk factors in patients with Type 2 diabetes mellitus

AIM

Impaired exercise capacity, adiponectin, MMPs and TIMPs have all been implicated in the development of cardiovascular disease. The aim of our study was to determine the effects of rosiglitazone on these factors in diabetic patients.

METHODS

Seventy individuals with Type 2 diabetes were assigned randomly to either a rosiglitazone group (8 mg/day, RG) or a control group (CG) for 6 months. All participants took gliclazide 160 mg plus metformin 1700 mg in stable dose. None of the individuals had diabetic complications or had previously participated in an exercise programme. Anthropometric parameters, VO2 peak, oxygen pulse, glycaemic indices, lipid profile, adiponectin, insulin resistance, blood pressure and serum MMP-9, TIMP-1, TIMP-2 levels were assessed at baseline and at the end of the study. After Bonferroni adjustment, a P-value < 0.017 was assumed to be statistically significant.

RESULTS

Rosiglitazone treatment significantly increased VO2 peak (P < 0.0001), the duration of the exercise test (P < 0.0001), oxygen pulse (P = 0.010) and TIMP-2 levels (P = 0.008) in comparison with CG. Insulin resistance, hyperglycaemia, diastolic blood pressure and MMP-9 levels were also reduced (P < 0.017). Fat mass, lipid profile, TIMP-1 levels and MMP9 : TIMP-1 ratio were unaltered after rosiglitazone treatment. There were no significant changes in these parameters in control subjects. In univariate analysis, the rosiglitazone-induced increment of VO2 peak was associated with alterations in plasma adiponectin (r = 0.691), HOMA-IR (r = -0.782) and HbA(1c) (r = -0.676) (P < 0.017). These relationships retained significance after multiple regression analysis (P = 0.005).

CONCLUSIONS

Rosiglitazone treatment increases cardiorespiratory fitness and modulates favourably serum adiponectin, MMP-9 and TIMP-2 levels. Whether these effects produce cardiovascular benefits in the long term requires further investigation.

Congestive heart failure in the elderly diabetic

The elderly diabetic is a potential congestive heart failure patient. Cardiac involvement is multifactorial, particularly ischemic conditions because of the accumulation at that age of vascular risk factors and therefore the frequency of coronary damages. The elderly diabetic very often has high blood pressure, with the risk of developing a hypertensive heart disease. Beyond these issues, the effects of chronic hyperglycaemia and insulin resistance on the heart specifically alter left ventricle compliance and therefore diastolic function, thus accelerating the effects proper to aging. No specific recommendation has been published on the management of the elderly diabetic with congestive heart failure. Even at an advanced age, with a clinical diagnosis of congestive heart failure that is sometimes difficult to make, the cardiological evaluation should be conducted rigorously within a global evaluation, and treatment should follow the same rules as in younger patients, with great caution given to the iatrogenic risks inherent to this population.