scholarly journals Effects of dipeptidyl peptidase-4 inhibitor in insulin-resistant rats with myocardial infarction

2016 ◽  
Vol 229 (3) ◽  
pp. 245-258 ◽  
Author(s):  
Nattayaporn Apaijai ◽  
Tharnwimol Inthachai ◽  
Suree Lekawanvijit ◽  
Siriporn C Chattipakorn ◽  
Nipon Chattipakorn

Adverse cardiac remodeling after myocardial infarction (MI) leads to progressive heart failure. Obese-insulin resistance increases risks of MI and heart failure. Although dipeptidyl peptidase-4 (DPP4) inhibitor is known to exert cardioprotection, its effects on adverse remodeling after MI in obese-insulin-resistant rats are unclear. We hypothesized that DPP4 inhibitor reduces adverse left ventricular (LV) remodeling and LV dysfunction in obese-insulin-resistant rats with MI. Rats were fed either normal diet (ND) or high-fat diet (HFD) for 12 weeks to induce obese-insulin resistance, followed by left anterior descending coronary artery ligation to induce MI. Then, rats in each dietary group were divided into five subgroups to receive vehicle, enalapril (10mg/kg/day), metformin (30mg/kg/day), DPP4 inhibitor vildagliptin (3mg/kg/day), or combined metformin and vildagliptin for 8 weeks. Heart rate variability (HRV), LV function, pathological and biochemical studies for LV remodeling, and cardiomyocyte apoptosis were determined. Obese-insulin-resistant rats had severe insulin resistance and LV dysfunction. HFD rats had a higher mortality rate than ND rats, and all treatments reduced the mortality rate in obese-insulin-resistant rats. Although all drugs improved insulin resistance, HRV, LV function as well as reduced cardiac hypertrophy and fibrosis, vildagliptin effectively reduced cardiomyocyte cross-sectional areas more than enalapril and was related to markedly decreased ERK1/2 phosphorylation. In ND rats with MI, metformin neither improved LV ejection fraction nor reduced cardiac fibrosis. The infarct size and transforming growth factor-β expression were not different among groups. In obese-insulin-resistant rats with chronic MI, DPP4 inhibitor vildagliptin exerts better cardioprotection than enalapril in attenuating adverse LV remodeling.

2007 ◽  
Vol 293 (3) ◽  
pp. H1609-H1616 ◽  
Author(s):  
Margaret P. Chandler ◽  
Eric E. Morgan ◽  
Tracy A. McElfresh ◽  
Theodore A. Kung ◽  
Julie H. Rennison ◽  
...  

Clinical studies have shown a greater incidence of myocardial infarction in diabetic patients, and following an infarction, diabetes is associated with an increased risk for the development of left ventricular (LV) dysfunction and heart failure. The goal of this study was to determine if the progression of heart failure following myocardial infarction in type 2 diabetic (T2D) rats is accelerated compared with nondiabetic rats. Male nondiabetic Wistar-Kyoto (WKY) and T2D Goto-Kakizaki (GK) rats underwent coronary artery ligation or sham surgery to induce heart failure. Postligation (8 and 20 wk), two-dimensional echocardiography and LV pressure measurements were made. Heart failure progression, as assessed by enhanced LV remodeling and contractile dysfunction, was accelerated 8 wk postligation in the T2D animals. LV remodeling was evident from increased end-diastolic and end-systolic diameters and areas in the GK compared with the WKY infarcted group. Furthermore, enhanced LV contractile dysfunction was evident from a greater deterioration in fractional shortening and enhanced myocardial performance index (an index of global LV dysfunction) in the GK infarcted group. This accelerated progression was accompanied by greater increases in atrial natriuretic factor and skeletal α-actin (gene markers of heart failure and hypertrophy) mRNA levels in GK infarcted hearts. Despite similar decreases in metabolic gene expression (i.e., peroxisome proliferator-activated receptor-α-regulated genes associated with fatty acid oxidation) between infarcted WKY and GK rat hearts, myocardial triglyceride levels were elevated in the GK hearts only. These results, demonstrating enhanced remodeling and LV dysfunction 8 wk postligation provide evidence of an accelerated progression of heart failure in T2D rats.


2010 ◽  
Vol 298 (1) ◽  
pp. H259-H262 ◽  
Author(s):  
Yue-Feng Chen ◽  
Rebecca A. Redetzke ◽  
Suleman Said ◽  
April J. Beyer ◽  
A. Martin Gerdes

It has been shown that hypothyroidism may lead to delayed wound healing after experimental myocardial infarction (MI) in rats and increased infarct size in dogs. However, the long-term effect of hypothyroidism on left ventricular (LV) remodeling after MI has not been determined. Adult female Sprague-Dawley rats with and without surgical thyroidectomy (TX) were used in the study. Four weeks after TX, MI or sham MI was performed on TX and non-TX rats. Rats from all groups were examined 4 wk later. Four weeks after TX, hypothyroid-induced LV dysfunction was confirmed by echocardiography. In terminal experiments 4 wk after MI, TX sham-MI rats showed smaller hearts and impaired LV function compared with non-TX sham-MI controls. TX + MI rats showed smaller hearts with bigger infarct areas, higher LV end-diastolic pressures, and greater impairment of relaxation (−dP/d t) compared with non-TX MI rats. Relative changes after MI between TX and non-TX rats for most other hemodynamic and echocardiographic indexes were similar. These results suggest that preexisting hypothyroidism exaggerates post-MI remodeling and worsens LV function, particularly diastolic function.


Open Heart ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. e001614
Author(s):  
Mohammad R Ostovaneh ◽  
Raj R Makkar ◽  
Bharath Ambale-Venkatesh ◽  
Deborah Ascheim ◽  
Tarun Chakravarty ◽  
...  

BackgroundMost cell therapy trials failed to show an improvement in global left ventricular (LV) function measures after myocardial infarction (MI). Myocardial segments are heterogeneously impacted by MI. Global LV function indices are not able to detect the small treatment effects on segmental myocardial function which may have prognostic implications for cardiac events. We aimed to test the efficacy of allogeneic cardiosphere-derived cells (CDCs) for improving regional myocardial function and contractility.MethodsIn this exploratory analysis of a randomised clinical trial, 142 patients with post-MI with LVEF <45% and 15% or greater LV scar size were randomised in 2:1 ratio to receive intracoronary infusion of allogenic CDCs or placebo, respectively. Change in segmental myocardial circumferential strain (Ecc) by MRI from baseline to 6 months was compared between CDCs and placebo groups.ResultsIn total, 124 patients completed the 6-month follow-up (mean (SD) age 54.3 (10.8) and 108 (87.1%) men). Segmental Ecc improvement was significantly greater in patients receiving CDC (−0.5% (4.0)) compared with placebo (0.2% (3.7), p=0.05). The greatest benefit for improvement in segmental Ecc was observed in segments containing scar tissue (change in segmental Ecc of −0.7% (3.5) in patients receiving CDC vs 0.04% (3.7) in the placebo group, p=0.04).ConclusionsIn patients with post-MI LV dysfunction, CDC administration resulted in improved segmental myocardial function. Our findings highlight the importance of segmental myocardial function indices as an endpoint in future clinical trials of patients with post-MI.Trial registration numberNCT01458405.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
C Bo-Htay ◽  
T Shwe ◽  
S Palee ◽  
T Pattarasakulchai ◽  
K Shinlapawittayatorn ◽  
...  

Abstract Background D-galactose (D-gal) induced ageing has been shown to exacerbate left ventricular (LV) dysfunction via worsening of apoptosis and mitochondrial dysfunction in the heart of obese rats. Hyperbaric oxygen therapy (HBOT) has been demonstrated to exert anti-inflammatory and anti-apoptotic effects in multiple neurological disorders. However, the cardioprotective effect of HBOT on inflammation, apoptosis, LV and mitochondrial functions in D-gal induced ageing rats in the presence of obese-insulin resistant condition has never been investigated. Purpose We sought to determine the effect of HBOT on inflammation, apoptosis, mitochondrial functions and LV function in pre-diabetic rats with D-gal induced ageing. We hypothesized that HBOT attenuates D-gal induced cardiac mitochondrial dysfunctions and reduces inflammation and apoptosis, leading to improved LV function in pre-diabetic rats. Methods Forty-eight male Wistar rats were fed with either normal diet or high-fat diet for 12 weeks. Then, rats were treated with either vehicle groups (0.9% NSS, subcutaneous injection (SC)) or D-gal groups (150 mg/kg/day, SC) for 8 weeks. At week 21, rats in each group were equally divided into 6 sub-groups: normal diet fed rats treated with vehicle (NDV) sham, normal diet fed rats treated with D-gal (NDDg) sham, high fat diet fed rats treated with D-gal (HFDg) sham, high fat diet fed rats treated with vehicle (HFV) + HBOT, NDDg + HBOT and HFDg + HBOT. Sham treated rats were given normal concentration of O2 (flow rate of 80 L/min, 1 ATA for 60 minutes), whereas HBOT treated rats were subjected to 100% O2 (flow rate of 250 L/min, 2 ATA for 60 minutes), given once daily for 2 weeks. Results Under obese-insulin resistant condition, D-gal-induced ageing aggravated LV dysfunction (Fig 1A) and impaired cardiac mitochondrial function, increased cardiac inflammatory and apoptotic markers (Fig 1B). HBOT markedly reduced cardiac TNF-α level and TUNEL positive apoptotic cells, and improved cardiac mitochondrial function as indicated by decreased mitochondrial ROS production, mitochondrial depolarization and mitochondrial swelling, resulting in the restoration of the normal LV function in HFV and NDDg rats, compared to sham NDDg rats. In addition, in HFDg treated rats, HBOT attenuated cardiac TNF-α level, TUNEL positive apoptotic cells and cardiac mitochondrial dysfunction, compared to sham HFDg rats, leading to improved cardiac function as indicated by increased %LV ejection fraction (LVEF) (Figure 1). Conclusion HBOT efficiently alleviates D-gal-induced-age-related LV dysfunction through mitigating inflammation, apoptosis and mitochondrial dysfunction in pre-diabetic rats. Figure 1 Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): 1. The National Science and Technology Development Agency Thailand, 2. Thailand Research Fund Grants


2006 ◽  
Vol 291 (1) ◽  
pp. R155-R162 ◽  
Author(s):  
Stephanie A. Dean ◽  
Junhui Tan ◽  
Roselyn White ◽  
Edward R. O’Brien ◽  
Frans H. H. Leenen

The present study tested the hypothesis that 17β-estradiol (E2) inhibits increases in angiotensin-converting enzyme (ACE) and ANG II type 1 receptor (AT1R) in the brain and heart after myocardial infarction (MI) and, thereby, inhibits development of left ventricular (LV) dysfunction after MI. Age-matched female Wistar rats were treated as follows: 1) no surgery (ovary intact), 2) ovariectomy + subcutaneous vehicle treatment (OVX + Veh), or 3) OVX + subcutaneous administration of a high dose of E2 (OVX + high-E2). After 2 wk, rats were randomly assigned to coronary artery ligation (MI) and sham operation groups and studied after 3 wk. E2 status did not affect LV function in sham rats. At 2–3 wk after MI, impairment of LV function was similar across MI groups, as measured by echocardiography and direct LV catheterization. LV ACE mRNA abundance and activity were increased severalfold in all MI groups compared with respective sham animals and to similar levels across MI groups. In most brain nuclei, ACE and AT1R densities increased after MI. Unexpectedly, compared with the respective sham groups the relative increase was clearest (20–40%) in OVX + high-E2 MI rats, somewhat less (10–15%) in ovary-intact MI rats, and least (<10–15%) in OVX + Veh MI rats. However, because in the sham group brain ACE and AT1R densities increased in the OVX + Veh rats and decreased in the OVX + high-E2 rats compared with the ovary-intact rats, actual ACE and AT1R densities in most brain nuclei were modestly higher (<20%) in OVX + Veh MI rats than in the other two MI groups. Thus E2 does not inhibit upregulation of ACE in the LV after MI and amplifies the percent increases in ACE and AT1R densities in brain nuclei after MI, despite E2-induced downregulation in sham rats. Consistent with these minor variations in the tissue renin-angiotensin system, during the initial post-MI phase, E2 appears not to enhance or hinder the development of LV dysfunction.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Mengjun Wang ◽  
Valerio Zaca ◽  
Alice Jiang ◽  
Itamar Ilsar ◽  
Matthew Ebinger ◽  
...  

Heart failure (HF) is associated with a high incidence of ventricular tachycardia (VT) and fibrillation (VF). Patients with HF in whom these lethal arrhythmias can be induced by electrophysiological (EP) testing carry a high risk of sudden cardiac death. We showed that chronic electrical carotid baroreflex activation therapy (BAT) with the Rheos® System (CVRx, Inc.) improves LV function, attenuates LV remodeling and restores autonomic sympathetic-parasympathetic balance in dogs with HF. This study examined the effects of long-term therapy with BAT on the induction of VT or VF in dogs with coronary microembolization-induced HF (LV ejection fraction ~20%). Eleven dogs with HF underwent EP testing at baseline prior to therapy and after 3 and 6 months of therapy with BAT and again 6 weeks after withdrawal of BAT therapy (n = 7) or no therapy at all (Control, n = 4). Programmed ventricular stimulation was performed from the right ventricular apex and included delivery of up to 4 extrastimuli at progressively shorter coupling intervals (in steps of 10 msec). The extrastimuli were delivered following 8 ventricular paced beats with a drive cycle length between 600 and 200 msec. If a sustained monomorphic VT or VF could not be induced, isoproterenol infusion was initiated to increase the sinus rate by ~30% and the EP stimulation protocol was repeated. At baseline, a sustained VT or VF was induced in all 11 dogs (100%). After 3 and 6 months of follow-up, all Control dogs (100%) were induced into sustained VT or VF. After 3 months of BAT, only 3 of 7 dogs (43%) were induced into sustained VT or VF. After 6 months of BAT, only 2 of 7 dogs (29%) were induced into sustained VT or VF. Finally after withdrawal of BAT therapy, all dogs (100%) were again induced into systained VT or VF. In addition to improving LV function and attenuating LV remodeling, long-term monotherapy with BAT markedly increases the threshold for lethal ventricular arrhythmias in dogs with chronic HF. This is a marked improvement over inducibility of lethal arrhythmias seen in historical untreated controls. This benefit of BAT supports the continued exploration of this device as a therapeutic modality for treating patients with chronic HF and increased risk of sudden cardiac death.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Doo Sun Sim ◽  
Youngkeun Ahn ◽  
Yun Hyeon Kim ◽  
Hyun Ju Seon ◽  
Keun Ho Park ◽  
...  

Background: There is a paucity of information on the time-dependent relationship of cardiac biomarkers to infarct size and left ventricular (LV) remodeling after myocardial infarction (MI). We sought to investigate the relationship between levels high-sensitivity C-reactive protein (hs-CRP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) and indices of infarct size and LV volume after acute MI. Methods: A total of 86 patients with ST-elevation MI within 12 hours after the symptom onset underwent delayed enhancement multi-detector computed tomography (DE MDCT) immediately after percutaneous coronary intervention (PCI) to determine infarct size. LV function and remodeling were assessed by echocardiography. Hs-CRP and NT-proBNP were serially measured at admission, 24 hours, and 2 months. DE MDCT and echocardiography were repeated at 2 months after PCI. Results: Levels of both hs-CRP and NT-proBNP at 24 hours showed positive correlation with infarct size at baseline and at 2 months, and negative correlation with LV ejection fraction at baseline and at 2 months. NT-proBNP at 2 months correlated with infarct size (r=0.561, p=0.007), LV ejection fraction (r= - 0.539, p=0.010), and LV end diastolic and systolic volume indices at 2 months (r=0.796, p=0.032 and r=0.831, p=0.021, respectively). NT-proBNP was higher in patients who developed LV remodeling at 2 months: 929 pg/mL vs. 134 pg/mL, p = 0.002. In contrast, hs-CRP at 2 months showed no relationship to infarct size, LV function, or LV volumes at 2 months. Conclusions: Elevated hs-CRP during active myocardial necrosis was associated with infarct size and LV dysfunction, whereas elevated levels of NT-proBNP early and late after the onset of acute MI were both correlated with infarct size, LV dysfunction, and LV remodeling.


2016 ◽  
Vol 72 (1) ◽  
Author(s):  
Alberto Genovesi Ebert ◽  
Furio Colivicchi ◽  
Marco Malvezzi Caracciolo ◽  
Carmine Riccio

The prevention of symptomatic heart failure represents the treatment of patients in the A and B stages of AHA/ACC heart failure classification. Stage A refers to patients without structural heart disease but at risk to develop chronic heart failure. The major risk factors in stage A are hypertension, diabetes, atherosclerosis, family history of coronary artery disease and history of cardiotoxic drug use. In this stage, blockers hypertension is the primary area in which beta blockers may be useful. Beta blockers seem not to be superior to other medication in reducing the development of heart failure due to hypertension. Stage B heart failure refers to structural heart disease but without symptoms of heart failure. This includes patients with asymptomatic valvular disease, asymptomatic left ventricular (LV) dysfunction, previous myocardial infarction with or without LV dysfunction. In asymptomatic valvular disease no data are available on the efficacy of beta blockers to prevent heart failure. In asymptomatic LV dysfunction only few asymptomatic patients have been enrolled in the trials which tested beta blockers. NYHA I patients were barely 228 in the MDC, MERIT and ANZ trials altogether. The REVERT trial was the only trial focusing on NYHA I patients with LV ejection fraction less than 40%. Metoprolol extended release on top of ACE inhibitors ameliorated LV systolic volume and ejection fraction. A post hoc analysis of the SOLVD Prevention trial demonstrated that beta blockers reduced death and development of heart failure. Similar results were reported in post MI patients in a post hoc analysis of the SAVE trial (Asymptomatic LV failure post myocardial infarction). In the CAPRICORN trial about 65% of the patients were not taking diuretics and then could be considered asymptomatic. The study revealed a reduction in mortality and a non-significant trend toward reduction of death and hospital admission for heart failure. Conclusions: beta blockers are not specifically indicated in stage A heart failure. On the contrary, in most of the stage B patients, and particularly after MI, beta blockers are indicated to reduce mortality and, probably, also the progression toward symptomatic heart failure.


Author(s):  
Edwin K. Jackson ◽  
Zaichuan Mi ◽  
Delbert G. Gillespie ◽  
Dongmei Cheng ◽  
Stevan P. Tofovic

Background The long‐term effects of dipeptidyl peptidase 4 (DPP4) inhibitors on blood pressure and cardiovascular and renal health remain controversial. Herein, we investigated the extended (>182 days) effects of DPP4 inhibition in a model of spontaneous hypertension, heart failure, diabetes mellitus, obesity and hyperlipidemia. Methods and Results Adult obese spontaneously hypertensive heart failure rats (SHHF) were implanted with radio transmitters for measurement of arterial blood pressures. Two weeks later, SHHF were randomized to receive either a DPP4 inhibitor (sitagliptin, 80 mg/kg per day in drinking water) or placebo. At the end of the radiotelemetry measurements, renal and cardiac function and histology, as well as other relevant biochemical parameters, were assessed. For the first 25 days, mean arterial blood pressures were similar in sitagliptin‐treated versus control SHHF; afterwards, mean arterial blood pressures increased more in sitagliptin‐treated SHHF ( P <0.000001). The time‐averaged mean arterial blood pressures from day 26 through 182 were 7.2 mm Hg higher in sitagliptin‐treated SHHF. Similar changes were observed for systolic (8.6 mm Hg) and diastolic (6.1 mm Hg) blood pressures, and sitagliptin augmented hypertension throughout the light‐dark cycle. Long‐term sitagliptin treatment also increased kidney weights, renal vascular resistances, the excretion of kidney injury molecule‐1 (indicates injury to proximal tubules), renal interstitial fibrosis, glomerulosclerosis, renal vascular hypertrophy, left ventricular dysfunction, right ventricular degeneration, and the ratios of collagen IV/collagen III and collagen IV/laminin in the right ventricle. Conclusions These findings indicate that, in some genetic backgrounds, long‐term DPP4 inhibitor treatment is harmful and identify an animal model to study mechanisms of, and test ways to prevent, DPP4 inhibitor–induced pathological conditions.


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