Comparative study of the bioactive compounds of olive products on cardioprotection from ischemia-reperfusion injury in mice with metabolic syndrome

Background/Introduction

The main bioactive compounds of olive products, oleuropein (OL), hydroxytyrosol (HT), oleocanthal (OC) and oleanolic Acid (OA) exert multiple benefits in cardiovascular diseases. However, their potential cardioprotective effect after chronic administration at a nutritional dose has not been studied in metabolic syndrome (MS).

Purpose

We evaluated and compared possible cardioprotective effects of chronic oral treatment with OL, HT, OC and OA in a mouse model of diet-induced MS.

Methods

We initially explored if OL, HT, OC, OA exert cardioprotection against ischemia-reperfusion (I/R) injury after chronic administration in healthy animals. The nutritional dose was selected as the equivalent to the estimated daily phenolic intake in humans following the Mediterranean diet. C57Bl6 mice were randomized into 5 groups and treated daily for 6 weeks as followed: i) DMSO 5%, ii) OL (20.6 mg/kg), iii) HT (5.9 mg/kg), iv) OC (11.6 mg/kg), v) OA (17.4 mg/kg). All animals were then subjected to I/R (30/120 min) and infarct size (IS) was determined. In a second cohort, C57Bl6 mice were fed with western diet for 14 weeks to induce MS. At 8th week, mice were randomized into 6 groups: i) Normal Saline (NS), ii) OL, iii) HT, iv) DMSO 5%, v) OC, vi) OA and treated daily with the assigned compound/vehicle for the last 6 weeks. At baseline, 8th and 14th week, body weight, mean arterial blood pressure (MAP) and fasting glucose levels were evaluated. Blood samples were collected at baseline and 14th week for the determination of the lipid profile and the mice were subjected to IR (30/120 min).

Results

OL, OC and OA reduced IS in healthy animals (p<0.05 vs. DMSO). Similarly, the IS was significantly reduced in MS mice after OL (19.4±2,6% vs. NS 34.7±1.6%, p<0.01), OC and OA (12.3±2.9% and 18.3±0.4% vs. DMSO 35.6±4.9%, p<0.0001 and p<0.001). HT failed to reduce the IS in both cohorts. Body weight, glucose, cholesterol and LDL levels were significantly elevated in the control groups, whereas MAP did not change. OL was the only compound that reduced fasting glucose and LDL levels, while OA reduced total cholesterol and LDL levels (p<0.01). OC and HT did not alter the lipidemic parameters. None of the bioactive compounds affected the body weight, MPA and triglyceride levels.

Conclusion(s)

Chronic treatment with nutritional doses of OL, OC and OA reduce IS in mice with MS; OC displays the most potent cardioprotective effect. OL ameliorates hyperglycemia and decreases LDL, while OA lowers both total cholesterol and LDL. Investigation of the underlying mechanisms and combined treatment with these compounds could emerge novel molecular cardioprotective approaches explaining possible additive beneficial effects in patients with MS.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Operational Program “Competitiveness, Entrepreneurship and Innovation”, under the call “RESEARCH – CREATE – INNOVATE” (project code: 5048539).

A 10-year follow-up study of the cardiovascular risk factors in children aged 6–16 years

Background

Obesity and arterial hypertension in children represent well recognized risk factors for future cardiovascular (CV) events during early adult life. We aimed to investigate any changes regarding several parameters affecting the CV status of children aged 6–16 years after a 10-year follow-up period.

Methods

A cohort of 143 children 6–16 years old (79/64 boys/girls, mean age 9±2 years) was evaluated regarding food habits (fish/chicken/vegetables/fruit per week), obesity (BMI), office blood pressure (SBP/DBP), aortic stiffness (PWV), lipid profile (HDL, LDL) and sports activity (hours of exercise/week). After a 10-years follow-up period, we managed to re-evaluate 62/143 (43%) young adults (33/31 boys/girls, mean age 20±2 years) for the same parameters plus endothelial function estimated by endothelial glycocalyx integrity (PBR5–25).

Results

We found that after 10 years, young adults compared to themselves had increased BMI, SBP/DBP and PWV (p<0.001), decreased HDL and LDL (p<0.001 and p=0.004, respectively), increased consumption of chicken and vegetables (p<0.001 and p=0.05, respectively) and decreased consumption of fish and fruits (p=0.004 and p=0.001, respectively) per week and finally increased weekly hours of sports activity (p=0.005). Mean PBR5–25 was 1.9±0.2 μm. Regarding obesity, the majority of children were overweight (20%) or obese (41%) while the majority of young adults were normoweight (60%) and only 11% obese. Regarding arterial hypertension (mean value of a triple office BP measurement), we measured BP >95th percentile in 7% of the children (50% of children had finally white coat hypertension) while just one young adult (2%) had BP >140 mmHg).

Conclusions

After 10 years, children became young adults with an improved status regarding obesity, normal BP levels, favorable lipid profile as for LDL levels, almost healthy food habits who also spend more hours in sport activities. However, HDL was decreased, aortic stiffness was increased while there are no comparable data regarding endothelial glycocalyx integrity. Overall, the profile of young adults seems protective against future CV events.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Endothelial glycocalyx integrity and microvascular perfusion are associated with novel echocardiographic markers and carotid intima-media thickness in patients with psoriasis

Background/Introduction

Psoriasis has been associated with vascular and myocardial dysfunction through mechanisms of inflammation and oxidative stress.

Purpose

We aimed to evaluate sublingual microvascular perfusion and glycocalyx barrier properties in psoriasis patients, as well as their correlation with coronary microcirculatory function and markers of myocardial deformation and atherosclerosis (carotid intima-media thickness, cIMT).

Methods

We examined 297 patients with psoriasis and 150 controls, adjusted for age, sex, and atherosclerotic risk factors. Perfusion boundary region (PBR), a marker of glycocalyx barrier function, was measured non-invasively in sublingual microvessels with a diameter ranging from 5–25μm using a dedicated camera (Sidestream Dark Field imaging, Microscan, GlycoCheck). Increased PBR indicates reduced glycocalyx thickness. Indexes of microvascular perfusion, including red blood cell (RBC) filling percentage and functional microvascular density, were also calculated. We measured coronary flow reserve (CFR), cIMT and markers of myocardial deformation by speckle tracking imaging utilizing echocardiography [peak twisting, the percentage changes between peak twisting, and untwisting at mitral valve opening (%dpTw-UtwMVO), at peak (%dpTw-UtwPEF), and the end of early LV diastolic filling (%dpTw-UtwEDF)].

Results

Psoriasis patients had higher PBR5–25 compared to controls (2.13±0.29 versus 1.78±0.25μm, p<0.05). There was an inverse association of PBR5–25 with perfused microvascular density (r=−0.42, p<0.001) and RBC fraction (r=−0.80, p<0.001). In psoriatic population, PBR5–25 was inversely correlated to CFR (r=−0.30, p=0.045). Increased values of PBR5–9 were associated with reduced untwisting at the end of the mitral inflow E wave (r=−0.24, p=0.006) and reduced %dpTw-UtwMVO (r=−0.35, p<0.001). Furthermore, decreased RBC filling percentage and perfused microvascular density were related to worse LV longitudinal strain and increased cIMT (p<0.05). Finally, a positive correlation between perfused microvascular density and %dpTw-UtwMVO was observed in patients with psoriasis (p<0.05).

Conclusion

Endothelial glycocalyx thickness is reduced in patients with psoriasis and is associated with impaired coronary and myocardial function, and vascular atherosclerosis.

Funding Acknowledgement

Type of funding sources: None.

Effects of hormone replacement therapy on arterial stiffness, endothelial function and myocardial deformation in women with Turner syndrome

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction: Turner syndrome (TS) is associated with congenital or acquired cardiovascular diseases.

Purpose

We investigated whether hormone replacement therapy (HRT) affects arterial elastic properties, endothelial function and myocardial deformation in women with TS.

Methods

In 25 women with TS (age: 29 ± 9years) we measured  in the oestrogen phase of HRT cycle and 1 month after discontinuation of HRT: a)Pulse wave velocity (PWV-Complior), central systolic blood pressure (cSBP) and augmentation index (AI) of the aortic pulse wave, b)perfused boundary region (PBR) of the sublingual arterial microvessels, as a marker of endothelial glycocalyx thickness, c)carotid intima-media thickness (cIMT), d)flow-mediated dilatation (FMD) of the brachial artery and percentage difference of FMD (FMD%), and e)global LV longitudinal strain (GLS) and left atrium (LA) strain using speckle tracking echocardiography. Ten healthy subjects of similar sex, age and BMI served as control group.

Results

Compared to controls, women with TS under HRT had higher PWV (9.1 ± 2.4 vs. 7.5 ± 0.5m/s), AI (18 [7 to 27] vs. 5.8 [-10 to 19]%), cSBP (130 ± 15 vs. 121 ± 6mmHg), cIMT (0.66 ± 0.06 vs. 0.55 ± 0.05mm), FMD (7.2 ± 4 vs. 10 ± 2.3%) and lower LA volume index (14.3 ± 4 vs. 24 ± 13 mL/m²) and GLS (-18.8 ± 2.7 vs. -21.9 ± 1.5) (p < 0.05 for all comparisons). PBR was negatively related with FMD% (r=-0.58, p = 0.022) in women with TS under HRT. One month after discontinuation of HRT, all women reduced PWV, AI, cSBP and increased FMD. There were no statistically significant changes in BMI, PBR, cIMT, LA volume index, LA strain and LV GLS (p > 0.05 for all comparisons) (Table). The percent decrease of cSBP was associated with the percent decrease of PWV (r = 0.54) and inversely related with the percent increase of FMD (r=-0.57) (p < 0.05 for all comparisons).

Conclusions

Hormone replacement treatment in women with TS deteriorates arterial stiffness and endothelial function probably due to increased central arterial blood pressure.

Women with Turner syndrome under HRT (n = 25) Women with Turner syndrome one month after discontinuation of HRT (n = 25) p-value PWV, m/s 9.1 ± 2.4 7.8 ± 1.7 0.028 Central SBP, mmHg 130 ± 15 123 ± 14 0.007 PBR, 5-25μm 2.11 ± 0.3 2.12 ± 0.2 0.983 cIMT, mm 0.66 ± 0.06 0.67 ± 0.06 0.947 FMD, % 7.2 ± 4 11.7 ± 6 0.042 LA strain, % 51 ± 12 54 ± 15 0.400 LV GLS, % -18.8 ± 2.7 -19.3 ± 2.3 0.594 Table

Effects of glucagon like peptide-1 receptor agonists, sodium-glucose cotransporter-2 inhibitors and their combination on vascular function and myocardial work index in patient with type-2 diabetes

Background/Introduction

Type-2 diabetes mellitus (T2DM) is associated with endothelial and myocardial dysfunction.

Purpose

We investigated the effects of insulin, glucagon like peptide-1 receptor agonists (GLP-1RA), sodium-glucose cotransporter-2 inhibitors (SGLT-2i) and their combination on vascular and cardiac function of T2DM patients.

Methods

A hundred-sixty T2DM patients were randomized to insulin (n=40), liraglutide (n=40), empagliflozin (n=40) or their combination (GLP-1RA+SGLT-2i) (n=40) as add-on to metformin. We measured at baseline, 4 and 12 months post-treatment: a) perfused boundary region (PBR) of the sublingual arterial microvessels (marker of glycocalyx thickness), b) pulse wave velocity (PWV), central systolic blood pressure (cSBP), c) global LV longitudinal (GLS), circumferential (GCS) and radial (GRS) strain, d) the ratio PWV/GLS, as an index of ventricular-arterial interaction, e) myocardial work index (GWI) using speckle tracking imaging.

Results

Twelve months post-treatment, all patients improved PBR, PWV, GLS, GCS and GRS (p<0.05). GLP-1RA, SGLT-2i and their combination showed a greater reduction of PBR, PWV and cSBP than insulin, despite a similar HbA1c reduction (p<0.05). GLP-1RA or GLP-1RA+SGLT-2i provided a greater decrease of PWV/GLS (28.1% and 31% vs. 11.1% and 14.5%) and a greater increase of GWI (12.7% and 17.4% vs. 3.1% and 2%) compared with insulin or SGLT-2i. SGLT-2i or GLP-1RA+SGLT-2i showed a greater decrease of PWV (10.1% and 13%), cSBP than insulin or GLP-1RA (PWV: 3.6% and 8.6%) (p<0.05 for all comparisons) (Table 1). The dual therapy showed the greatest effect on measured markers in patients with LVEF <55% (p<0.05).

Conclusions

Twelve-month treatment with GLP-1RA, SGLT-2i and their combination showed a greater improvement of vascular markers and effective cardiac work than insulin in T2DM. The combined therapy was superior to either insulin, or GLP-1RA and SGLT-2i separately.

Funding Acknowledgement

Type of funding source: None

The new LDL-C target <55 mg/dL is achieved by less than 40% of very high risk patients with familial hypercholesterolaemia despite receiving PCSK9 inhibitors: real world data

Background

The recently published ESC/EAS guidelines for the management of dyslipidaemias have lowered the low-density lipoprotein cholesterol (LDL-C) target in the very high risk patients below 55 mg/dL.

Purpose

To examine how achievable is this target in very high risk patients receiving a proprotein convertase subtilisin/kexin type 9 inhibitor (PCSK9i) on top of lipid-lowering treatment (LLT).

Methods

The cohort comprised 158 patients who attended the lipid clinic of 3 hospitals in Greece and started treatment with PCSK9i. Patients were requested to attend the lipid clinic 3 months after the initiation of PCSK9i.

Results

Ninety percent of patients had heterozygous familial hypercholesterolaemia (heFH) and 75% had cardiovascular disease (CVD). One hundred forty patients were classified as very high risk because they had either cardiovascular disease (CVD) or heFH with an additional risk factor for whom a target <55 mg/dL is currently recommended. Of those very high risk patients, 105 (75%) were given PCSK9i due to failure to achieve LDL-C targets despite maximum LLT (high intensity statin at maximum tolerated dose + ezetimibe) while in the rest of cases the indication was statin intolerance. The mean reduction of LDL-C at 3 months was 56.2%. Among 105 very high risk patients (all had heFH), LDL-C below 55 mg/dL was achieved by 37.1% while the previously LDL-C target <70 mg/dL was achieved by 60% (Figure 1).

Conclusions

The new LDL-C target <55 mg/dL is achieved by <40% of very high risk patients with heFH despite receiving triple LLT, i.e. PCSK9i + statin + ezetimibe. This therapeutic gap suggests that there is still need for more effective LLT in very high risk heFH patients to maximize their clinical benefit.

Figure 1

Funding Acknowledgement

Type of funding source: None

Long-term antihypertensive treatment improves ventricular-arterial interaction in hypertensive patients: a 3-year follow-up study

Background

We investigated the effects of antihypertensive treatment on vascular function, longitudinal deformation and ventricular-arterial interaction in hypertensives.

Methods

In 200 untreated patients with arterial hypertension (age 52.5±11.6 years, 56% females), we measured at baseline and after a 3-year of antihypertensive treatment (160 received ACEi± diuretics and 40 CCBs± diuretics): a) 24h ambulatory blood pressure b) Carotid-femoral pulse wave velocity (PWV) b) Coronary flow reserve (CFR), LV mass index (LVMI), the global longitudinal strain (GLS). We calculated the ratio of PWV/GLS (-m/sec%) reflecting the ventricular-arterial interaction.

Results

Compared to baseline, there was an improvement of GLS (−19.9±3.4 vs. −18.7±3.1%), post-treatment. In parallel, there were improvement in CFR (2.72±0.61 vs. 2.55±0.64), PWV (10.3±1.9 vs. 11.2±2.1 m/s), LVMI and PWV/GLS (−0.539±0.146 vs. −0.618±0.178 -m/sec%) (p<0.01 for all comparisons). By multivariate analysis, the reduction of 24h meanBP as well as PWV independently determined the respective improvement of GLS (b=0.478, b=0.248, respectively, p<0.001). By ANOVA, the interaction term between changes of all the above parameters and antihypertensive treatment (ACE inhibitors vs calcium channel blockers) was not significant (p>0.05).

Conclusions

Long-term optimal blood pressure control with ACE inhibitors and CCBs improves LV longitudinal deformation along with reduction of arterial stiffness, leading to improved ventricular-arterial interaction in hypertensives.

Funding Acknowledgement

Type of funding source: None

Association arterial stiffness reduction with improved left ventricular longitudinal and torsional deformation after 3 years of antihypertensive treatment

Background

We investigated the effects of antihypertensive treatment on vascular function, longitudinal and torsional deformation in hypertensives.

Methods

In 200 untreated patients with arterial hypertension (age 52.5±11.6 years, 56% females), we measured at baseline and after a 3-year of antihypertensive treatment (160 received ACEi± diuretics and 40 CCBs± diuretics): a) 24h ambulatory blood pressure b) Carotid-femoral pulse wave velocity (PWV) b) Coronary flow reserve (CFR), LV mass index (LVMI), the global longitudinal strain (GLS) and diastolic (LongSRSE) strain rate, peak twisting (Tw-deg) and untwisting at mitral valve opening (UtwMVO), at peak E (UtwE) and at the end of the E wave (UtwendE) of the mitral inflow as well as twisting (TwVel-deg/sec) velocity using speckle tracking imaging. We calculated the % change of LV untwisting as difference between peakTw and UtwMVO, UtwpeakE and UtwendE.

Results

Compared to baseline, there was an improvement of GLS (−19.9±3.4 vs. −18.7±3.1%), LongSRS (−1.08±0.22 vs. −0.98±0.26 1/s), LongSRE (1.09±0.36 vs. 0.99±0.31 1/s), peak Tw (16.2±5.1 vs. 18.7±5.9 deg), Tw velocity, and the %LV untwisting (31.04±19.28 vs 26.02±15.69% at MVO, 60.04±19.78 vs 53.96±19.76% at peakE and 79.98±14.24 vs 75.90±17.01% at endE) post-treatment. In parallel, CFR (2.72±0.61 vs. 2.55±0.64), PWV (10.34±1.93 vs. 11.2±2.08 m/s) and LVMI were improved (p<0.01 for all comparisons). By ANOVA, the interaction term between changes of all the above parameters and antihypertensive treatment (ACE inhibitors vs calcium channel blockers) was not significant (p>0.05). By multivariate analysis, the reduction of 24h meanBP and PWV independently determined the respective improvement of GLS (b=0.478 and b=0.248 respectively), LongS (b=0.428 and b=0.201 respectively) as well as Twisting (b=0.449 and b=0.294 respectively) after adjusting for changes in LV mass, CFR and atherosclerotic risk factors (p<0.05).

Conclusions

Long-term optimal blood pressure control with ACE inhibitors and CCBs improves LV longitudinal and torsional mechanics in hypertensives in parallel with arterial stiffness and blood pressure. This improvement in LV deformation and twisting was independently related to changes in arterial blood pressure and arterial stiffness.

Funding Acknowledgement

Type of funding source: None

Glucagon like peptide-1 receptor agonists and their combination with sodium-glucose cotransporter-2 inhibitors improve myocardial deformation and work index in type-2 diabetes after 12-month treatment

Background/Introduction

Type-2 diabetes mellitus (T2DM) exacerbates mechanisms of atherosclerosis and heart failure.

Purpose

We investigated the effects of insulin, glucagon like peptide-1 receptor agonists (GLP-1RA), sodium-glucose cotransporter-2 inhibitors (SGLT-2i) and their combination on LV myocardial function of T2DM patients.

Methods

A hundred-sixty T2DM patients (age: 58±10 years) were randomized to insulin (n=40), liraglutide (n=40), empagliflozin (n=40) or their combination (GLP-1RA+SGLT-2i) (n=40) as add-on to metformin. We measured at baseline, 4 and 12 months post-treatment: a) global LV longitudinal strain (GLS), systolic (LongSr) and diastolic (LongSrE) strain rate, global circumferential (GCS) and radial (GRS) strain, peak twisting (pTw), peak twisting velocity (pTwVel) and peak untwisting velocity (pUtwVel), b) global myocardial global work index (GWI), global constructive (GCW) and global wasted myocardial work (GWW) derived by pressure-myocardial strain loops using speckle tracking imaging.

Results

At 4 and 12 months post-treatment, all patients improved GLS, GCS, GRS and pUtwVel (p<0.05). At 12 months, GLP-1RA or GLP-1RA+SGLT-2i provided a greater increase of GLS (11.5% and 13% vs. 6.8% and 2.3%), GCS (11.9% and 14.6% vs. 7.3% and 3.4%), GRS (3.8% and 4.3% vs. 2.2% and 1.6%), GWI (12.7% and 17.4% vs. 3.1% and 2%), GCW (12.3% and 15% vs. 2.2% and 7.8%) and a greater reduction of GWW (38.7% and 41.6% vs. 13.5% and 4.9%) compared with insulin or SGLT-2i, despite a similar HbA1c reduction (p<0.05 for all comparisons) (Table). Patients under combined treatment with GLP-1RA+SGLT-2i achieved a 2-fold reduction of pTw and a 2-fold increase of pUtwVel than those under each one regimen or insulin (p<0.05). The dual therapy showed the greatest effect on measured myocardial markers in patients with LVEF <55% (p<0.05).

Conclusions

Twelve-month treatment with GLP-1RA or combination of GLP-1RA and SGLT-2i showed a greater improvement of myocardial deformation and effective cardiac work than insulin or SGLT-2i treatment in T2DM. The combined therapy as second line was superior to either insulin, or GLP-1RA and SGLT-2i separately.

Funding Acknowledgement

Type of funding source: None

Inhibition of interleukin-6 by tocilizumab improves endothelial glycocalyx and myocardial work index in patients with rheumatoid arthritis

Background/Introduction

Tocilizumab, an interleukin-6 receptor blocker is used for the treatment of rheumatoid arthritis (RA).

Purpose

We investigated the effects of tocilizumab on endothelial glycocalyx and myocardial function in patients with RA.

Methods

Eighty patients with RA (age: 64±9 years) were randomized to tocilizumab (n=40) or prednisolone (n=40)for 3 months. We measured at baseline and 3 months post-treatment: a) perfused boundary region (PBR) of the sublingual arterial microvessels (increased PBR indicates reduced glycocalyx thickness), b) pulse wave velocity (PWV-Complior), central systolic blood pressure (cSBP) and augmentation index (AI), c) global LV longitudinal strain (GLS), longitudinal systolic (LongSr) and diastolic (LongSrE) strain rate, d) global myocardial work index (GWI), global constructive (GCW) and global wasted work (GWW) using speckle tracking imaging.

Results

At baseline, all patients had similar disease activity score and markers of vascular and myocardial function. Compared with baseline, patients under tocilizumab had reduced PBR (2.14±0.2 vs. 1.97±0.2μm), PWV (11±3 vs. 10.3±2m/s), cSBP (134±18 vs. 129±16mmHg) and LongSrE (0.91±0.3 vs. 1±0.3 1/s) at 3 months (p<0.05). There were no statistically significant differences in the above measured markers in patients under prednisolone (p>0.05) (Table). Compared with prednisolone, tocilizumab treatment achieved a greater increase of GLS (8.5% vs. 2.4%), GWI (12.2% vs. 2.7%), GCW (10.3% vs. 5.9%) and a greater reduction of GWW (−30% vs. −13%) (p<0.05 for all comparisons), despite a similar reduction in C-reactive protein post-treatment. The percent decrease of PBR was associated with the percent decrease of cSBP (r=0.46), PWV (r=0.37) and reversely related with the percent improvement of GLS (r=−0.43) and GWI (r=−0.39) (p<0.05).

Conclusions

IL-6 inhibition by tocilizumab improves endothelial and vascular function leading to a greater increase of effective myocardial work compared to prednisolone in patients with RA.

Funding Acknowledgement

Type of funding source: None

Sodium-glucose cotransporter-2 inhibitors and their combination with glucagon like peptide-1 receptor agonists improve endothelial glycocalyx and arterial stiffness in type-2 diabetes

Background/Introduction

Type-2 diabetes mellitus (T2DM) is associated with endothelial and arterial dysfunction.

Purpose

We investigated the effects of insulin, glucagon like peptide-1 receptor agonists (GLP-1RA), sodium-glucose cotransporter-2 inhibitors (SGLT-2i)and their combination on endothelial and arterial function of T2DM patients.

Methods

A hundred-sixty T2DM patients (age: 58±10 years) were randomized to insulin (n=40), liraglutide (n=40), empagliflozin (n=40) or their combination (GLP-1RA+SGLT-2i) (n=40)as add-on to metformin. We measured at baseline, 4 and 12 months post-treatment: a) perfused boundary region (PBR) of the sublingual arterial microvessels (ranged from 5 to 25μm) using Sideview Darkfield imaging. Increased PBR indicates reduced glucocalyx thickness, b) pulse wave velocity (PWV-Complior), central systolic blood pressure (cSBP) and augmentation index (AI) of the aortic pulse wave.

Results

Twelve months post-treatment, all patients improved PBR, PWV and AI (p<0.05). GLP-1RA, SGLT-2i and their combination showed a greater reduction of PBR, PWV and cSBP than insulin, despite a similar HbA1c reduction (p<0.05). SGLT-2i or combined therapy with GLP-1RA and SGLT-2i showed a greater decrease of PWV (−10.1% and −13% vs. −3.6% and −8.6%) and cSBP (−3% and −5.5% vs. −0.8% and −1.5%)than insulin or GLP-1RA (p<0.05 for all comparisons). GLP-1RA or GLP-1RA+SGLT-2i provided a greater decrease of AI (−42.7% and −48.6% vs. +6.2% vs. −3.8%) compared with insulin or SGLT-2i (Table). The dual therapy showed the greatest effect on measured markers in patients with LVEF <55% (p<0.05).

Conclusions

Twelve-month treatment with SGLT-2i and its combination with GLP-1RA, showed a greater improvement on arterial elastic properties than GLP1RA or insulin treatment in T2DM. The combined therapy as second line was superior to either insulin, or GLP-1RA and SGLT-2i separately.

Funding Acknowledgement

Type of funding source: None

Effects of electronic cigarette on platelet and vascular function after one month of use

Background and aims

Smoking is a major factor that contributes to the development of cardiovascular disease. Smoking cessation delays progress of coronary artery disease. Electronic cigarette is proposed as a bridge to smoking cessation. We examined its effects on platelet function after 1 month of use compared to tobacco smoking.

Patients and methods

40 current smokers (mean age 48 years±5) without cardiovascular disease were randomized to smoke either a conventional cigarette (conv-cig) or an electronic cigarette (e-cig) (electronic cigarette fluid with nicotine concentration of 12 mg/dL) for one month. All subjects smoked an electronic cigarette with nicotine concentration 12 mg/dL for one month. Measurements were performed at baseline and after one month of smoking the conventional or electronic cigarette. We measured a) perfused boundary region (PBR) of the sublingual arterial micro vessels (range 5–25 micrometers), a marker inversely related with glycocalyx thickness, b) pulse wave velocity (PWV), central systolic blood pressure (cSBP) and augmentation index (AIx), c) platelet function by two different methods, namely the novel Platelet Function Analyzer PFA-100 and the traditional Light Transmission Aggregometry (LTA) d) the exhaled CO level (parts per million-ppm) as a smoking status marker; and e) the plasma malondialdehyde (MDA) levels, as an oxidative stress burden index.

Results

After 1 month of electronic smoking, we did not observe any significant change in platelet function and arterial stiffness (p>0.05 for all markers) with the exception of a reduction of MDA (1.22±0.1 vs 1.09±0.1 μmol/L, p=0.03) and exhaled CO; 14.9±0.7 vs 5.9±0.7 ppm, p<0.001. Conversely, after continuation of conventional cigarette smoking for a month, platelet function was further impaired as assessed by PFA [125,5±31,1 vs 152,35±51,4 U, p=0.047) and by LTA (epinephrine as stimulator) [59,8%±16,1 vs 35,6%±19.1, p<0.001] and markers of arterial stiffness were deteriorated, as assessed by PWV (9,5±2,8 vs 10,3±2,9, p=0,028) and by Aixc (8,36±35,9 vs 30,4±21,6, p=0,004).

Conclusions

Electronic Cigarette smoking has a neutral effect on platelet function and arterial stiffness markers compared to conventional tobacco smoking which further deteriorates platelet and vascular function during one moth of use.

Funding Acknowledgement

Type of funding source: None

P1790 Is there any role of exercise Doppler echocardiography to unmask pulmonary hypertension (PH) in patients with systemic sclerosis and baseline echocardiographic measurements for PH in the gray zone?

Background

The usefulness of exercise Doppler echocardiography (EDE) is uncertain in identifying patients with pulmonary hypertension (PH). Recently the cut off value for the definition of PH was changed and was set at the level of mean pulmonary arterial pressure (PAP) >20 mmHg, measured by right heart catheterization (RHC).

Purpose

We examined whether EDE can unmask the presence of PH in patients with systemic sclerosis (SSc) whose baseline echocardiographic assessment for PH is non-diagnostic.

Methods

Forty-one patients with SSc (2 men and 39 women; mean age 61.2 ± 10 years) underwent treadmill symptom-limited EDE using a modified Bruce protocol. Tricuspid regurgitation velocity (TRV) was recorded within 60 seconds after the termination of the test. Inclusion criteria comprised: preserved left (ejection fraction >50%), and right ventricular function (tricuspid annulus plane systolic excursion >15 mm), lack of left side moderate or severe valvulopathy, presence of mild or moderate TR, satisfactory exercise tolerance and baseline TRV in the range of 2.6-3.0 m/s. All patients had RHC within 48 hours after EDE.

Results

In 5 cases the quality of post-exercise TRV was poor and further analysis was confined to 36 patients. RHC confirmed the presence of PH (mean PAP >20 mmHg) in 14 cases (38.9%). All patients had pulmonary capillary wedge pressure <15 mmHg. The increase in TRV from baseline to post-exercise was 1.25 ± 0.6 m/s. Ten patients developed post-exercise TRV ≥3.7 m/s of whom in 8 RHC validated PH. Post-exercise TRV was positively correlated with mean PAP obtained by RHC (r = 0,652, p < 0.001). A cut-off value of post-exercise TRV ≥3.7 m/s had a sensitivity of 57.1%, a specificity of 90% and a diagnostic accuracy of 77.8% in detecting PH validated by RHC.

Conclusions

EDE has a moderate diagnostic accuracy for the identification of PH in patients with SSc whose baseline echocardiographic measurements for PH lie in the gray zone.

P5598Long term outcome and quality of life following acute type A aortic dissection

Introduction

Acute aortic dissection (AAD) represents surgical emergency and current literature mainly consists of postoperative outcome reports. Long term outcome and quality of life have not extensively been investigated.

Purpose

This is a single center study to assess long term outcome and quality of life of patients who underwent emergency surgery for AAD.

Methods

From January 2007 until December 2009, 74 consecutive patients were operated for AAD type A in our hospital. Seventeen died during hospital stay and 12 died during follow-up. Mean follow up was 108±10 months. Seventeen patients refused to answer the SF-36 questionnaire; therefore our study group consists of 28 patients. The SF-36 Questionnaire was retrospectively obtained by phone calls, the first, fifth and tenth postoperative year and 2 summary scores are reported, physical (PCS) and mental (MCS).

Results

Our in-hospital mortality was 23%, late mortality 21.1% and the overall mortality was 39.2%. Significant differences in both physical and mental score over time were found among the 28 long-term survivors (Table). Both PCS and MCS at 1st, 5th and 10th year did not differ compared to age-matched general population but compared to subjects with one or more chronic diseases both PCS and MCS were both significantly better at 5yrs in our patients vs controls (p=0.0028 and p=0.0259, respectively). Likewise, at 5 years PCS but not MCS was better in comparison to subjects with a history of one hospitalization the preceding year (p=0.035 and p=0.1, respectively).

Descriptive statistics of physical and mental component summary score over time Score 1 year (FU1) 5 years (FU2) 10 years (FU3) p-value Mean (SD) Mean (SD) Mean (SD) PCS 45.4 (7.7) 50.3 (7.0) 46.8 (9.2) 0.008* MCS 42.8 (15.1) 49.7 (12.7) 49.1 (12.3) 0.001** PCS, Physical component summary; *1 vs 5: p=0.003, 1 vs 10: p=0.469, 5 vs 10: p=0.027. MCS, Mental component summary; **1 vs 5: p=0.001, 1 vs 10: p=0.001, 5 vs 10: p=0.939. SD, standard deviation.

Conclusion

Quality of life improves after the 1st post-operative year and is comparable to healthy subjects. Although acute dissection is a catastrophic event with high mortality despite successful and timely repair, long term survival and quality of life on the long term are favorable.

P4991Effects of the glucagon like peptide-1 receptor analogue, sodium-glucose co-transporter 2 and their combination on myocardial work index and vascular function in diabetes after 3-month treatment

Methods

A hundred twenty, patients with type 2 diabetes were randomized to receive the insulin +/− metformin (n=30), GLP-1A, liraglutide (n=30), the SGLT-2, empagliflozin (n=30) or their combination (GLP-1R+SGLT-2) for 3 months (n=30). We measured at baseline and after treatment a) pulse wave velocity (PWV), central systolic blood pressure (cSBP) b) the perfusion boundary region (PBR-micrometers) of the sublingual arterial microvessels, as a marker of endothelial glycocalyx thickness. c) global LV longitundinal strain (GLS), peak LV untwisting velocity and global myocardial work index (GWI) derived by pressure–myocardial strain loops using speckle tracking imaging and PWV to GLS ratio, as a marker of ventricular-arterial coupling

Results

All treatment groups had similar vascular and cardiac markers, glucose levels and HbA1 at inclusion (p>0.05). After treatment, all patients had improved GLS, PWV and increased LV twisting-untwisting velocities (p<0.05). Patients under GLP-1R, SGLT-2 and their combination achieved a significant reduction of PBR, PWV, central SBP and a greater increase of GWI (30%, 25% and 50% respectively) and LV untwisting velocities (p<0.05) than those under insulin (15% reduction of GWI), despite a similar reduction of HbA1 (p<0.05). The combination of GLP-1A and SGLT-2 showed a greater improvement of the measured markers than each treatment alone (table, p<0.05). The reduction of PBR (indicating improvement of glycocalyx thickness) was related with the changes in central SBP (r=0.40) and PWV (r=0.35) (p<0.05).

N=120 Insulin GLP-1A SGLT-2 GLP-1A + SGLT-2 P 3-months N=30 N=30 N=30 N=30 PBR, μm 2.27±0.3 2.17±0.3 2.17±0.3 1.99±0.2 <0.05 Central SBP, mmHg 136±20 127±16 126±11 124±10 <0.05 PWV, m/sec 11.7±0.5 9.5±0.5 9.3±0.5 9.2±0.5 <0.05 HbA1 7.1±1.5 6.6±0.3 6.7±0.6 6.2±0.6 0.8 Myocardial work index (GWI), mmHg% 1343±394 1579±245 1364±431 1784±593 <0.05 LV untwisting velocity, deg/sec −116±36 −123±36 −122±36 −130±36 <0.05 PWV/GLS ratio −0.77±0.2 −0.57±0.2 −0.66±0.3 −0.55±0.3 <0.05

Conclusion

Three-month treatment with GLP-1A, SGLT-2 and their combination showed a greater improvement of vascular markers, ventricular-arterial coupling and effective cardiac work than insulin treatment in type 2 diabetes.

P4445Effects of interleukin 17A inhibition on myocardial deformation and vascular function in psoriasis:one year follow-up

Background

Interleukin (IL)-17A activity is implicated in the clinical course of psoriasis. We investigated the effects of IL-17A inhibition on vascular and left ventricular (LV) function in psoriasis patients.

Methods

One hundred psoriasis patients received either an anti-IL-17A agent (secukinumab n=50), or cyclosporine treatment (n=50). At baseline and after 4 and 12 months of treatment, we measured (1) LV global longitudinal strain (GLS), strain rate (GLSR), strain rate at early diastole (GLSRE), twisting (LVtwist), (2) coronary flow reserve (CFR), (3) pulse wave velocity (PWV), (4) malondialdehyde (MDA) and protein carbonyl (PC) as markers of oxidative stress, (5) psoriasis severity and extent assessed by Psoriasis Area and Severity Index (PASI).

Results

Compared to treatment with cyclosporine, anti IL-17A treatment resulted in greater improvement in GLS (GLS: −16.7±3 at baseline vs −18.3±2.8 at 4 months vs −19±3 at 12 months post treatment with anti-IL-17 respectively, p=0.02, GLS: −16.8±2.9 at baseline vs −17.2±2.7 at 4 months vs −17.1±2.9 at 12 months post treatment with cyclosporine respectively, p=0.2), GLSR (−0.9±0.3 at baseline vs −1.08±0.3 at 4 months vs −1.11±0.2 at 12 months post treatment with anti-IL-17 respectively, p=0.02, −0.9±0.2 at baseline vs −0.95±0.2 at 4 months vs −0.96±0.2 at 12 months post treatment with cyclosporine respectively, p=0.5) GLSRE and LV twist (13.7±5.1 at baseline vs 18.1±6 at 4 months vs 17.8±5.6 at 12 months post treatment with anti-IL-17 respectively, p=0.001, 13±5.3 at baseline vs 13.8±5.6 at 4 months vs 15.5±5.3 at 12 months post treatment with cyclosporine respectively, p=0.6).Treatment with anti-IL-17A also resulted in greater improvement of CFR compared to cyclosporine treatment (2.6±0.3 at baseline vs 3±0.3 at 4 months vs 3.1±0.3 at 12 months post treatment with anti-IL-17 respectively, p=0.01, 2.7±0.4 at baseline vs 2.8±0.3 at 4 months vs 2.7±0.3 at 12 months post treatment with cyclosporine respectively, p=0.5) and PWV decreased after treatment with anti-IL-17 (10.2±1.8 at baseline vs 9.3±1.5 at 4 months vs 9.7±1.8 at 12 months post treatment with anti-IL-17 respectively, p=0.04, whereas higher values of PWV were observed after cyclosporine treatment (9.7±1.9 at baseline vs 10.8±1.7 at 4 months vs 11.2±2 at 12 months post treatment with cyclosporine respectively, p=0.02). PASI score was similarly improved after treatment with either anti-IL-17A or cyclosporine. Markers of oxidative stress were reduced after treatment with anti-IL-17A, in contrast to elevation of oxidative stress markers after treatment with cyclosporine. Changes of myocardial deformation markers and CFR after treatment with anti-IL-17A correlated with concomitant reduction of oxidative stress.

Conclusions

In psoriasis patients, inhibition of IL-17A results in a greater improvement of vascular and myocardial function compared with cyclosporine treatment.

P3552Estimating left ventricular myocardial deformation during cardiopulmonary exercise testing in patients with dilated cardiomyopathy and reduced ejection fraction

Background

Cardiopulmonary exercise testing (CPET) has been recognized as a valuable tool regarding the integrated estimation of exercise ability in patients with several cardiopulmonary diseases, dilated cardiomyopathy (DCM) included. Left ventricular (LV) abnormal myocardial deformation might be studied by newer echocardiography techniques. Aim of this study is to explore differences of LV myocardial deformation in DCM patients during a CPET session.

Methods

Forty-four DCM patients (mean age 53±13 years, 34 men) with an ejection fraction <50% (mean EF = 33±10%) and no history of previous pulmonary disease were subjected to maximum CPET. Simultaneously, we estimated LV myocardial deformation using speckle tracking imaging and we measured global longitudinal strain (GLS), longitudinal strain rate both at systole (GLSrS) and diastole (GLSrE) at baseline and at peak exercise. The difference between GLS at baseline-GLS at peak exercise was defined as GLS difference.

Results

All patients finished uneventfully CPET (peakVO2 = 20±7 ml/min/kg) and improved GLS at peak exercise (GLS difference = 1.5±2). We found that at peak exercise, systolic blood pressure (SBP) was increased (119±14 vs. 159±23 mmHg, p<0.001) while GLS (−12.5±4 vs. −14±5, p<0.001), GLSrS (−0.7±0.2 and −1.0±0.4, p<0.001) and GLSrE (0.7±0.4 and 1.0±0.6, p=0.001) were improved. A positive correlation between peakVO2 and GLS difference was found, independent of peak SBP (β=0.38, p=0.01).

Relationship between GLS dif and CPET

Conclusions

Patients with dilated cardiomyopathy and ejection fraction <50% present an increased exercise ability when they manage to improve LV GLS during maximum exercise. Consequently, LV GLS improvement during exercise characterizes beside patient's exercise ability the severity of heart failure as well.

P4435Effects of interleukin 6 inhibitor tocilizumab on endothelial glycocalyx, vascular and myocardial function compared to prednisolone

Background/Introduction

Tocilizumab, a humanised monoclonal antibody against the human interleukin-6 receptor, is used for the treatment of rheumatoid arthritis (RA).

Purpose

We investigated the effects of tocilizumab on arterial function, LV myocardial deformation and endothelial glycocalyx in RA patients.

Methods

80 patients with rheumatoid arthritis were randomized to tocilizumab (n=40) or prednisolone (n=40) for 3 months. At baseline and after 3-month treatment we assessed: a) carotid-femoral pulse wave velocity (PWV-Complior SP ALAM), b) LV longitudinal strain (GLS), systolic (LongSr) and diastolic (LongSrE) strain rate using speckle tracking echocardiography, c) perfused boundary region (PBR) of the sublingual arterial microvessels (ranged from 5–25μm) using Sideview Darkfield imaging (Microscan, Glycocheck). Increased PBR is considered an accurate index of reduced endothelial glucocalyx thickness, d) flow mediated dilatation (FMD) of the brachial artery after and percentage difference of FMD (FMD%) after hyperemia, e) coronary flow reserve (CFR) of the LAD using Doppler echocardiography, and f) malondialdehyde (MDA), protein carbonyls (PCs) and C-reactive protein (CRP) plasma levels.

Results

At baseline, all patients had similar disease activity score and markers of vascular and myocardial function. Compared to baseline, all patients had reduced CRP post treatment, while MDA and PCs levels were reduced only after tocilizumab treatment (p<0.05). The percent decrease of MDA was correlated with percent increase of GLS (p<0.001). Compared to baseline, tocilizumab-treated patients reduced PWV (11±3% vs. 10.3±2m/sec) and PBR (2.11±0.2 vs. 1.95±0.18μm) (Figure 1) and increased GLS (−16.1±2.9 vs. −17.6±2.5%), CFR (2.73±0.8 vs. 3.06±1), and FMD% (5.9±2.9 vs. 11.6±3.6) (p<0.05 for all comparisons). No significant changes were observed among prednisolone-treated patients.

Figure 1

Conclusions

IL-6 inhibition improves endothelial function and oxidative stress resulting to improved vascular function and LV myocardial deformation.

P6596S100A8/A9 and sRAGE peripheral blood levels in patients with heart failure and an implanted cardioverter/defibrillator: relation with sustained, fast ventricular arrhythmias

Background

Prediction of sudden cardiac death in heart failure (HF) remains suboptimal. Blood levels of the S100A8/A9 heterodimer protein complex and the soluble receptor of advanced glucation end product (sRAGE) are promising biomarkers in HF, reflecting inflammatory/fibrotic and apoptotic pathways, possibly involved in ventricular arrhythmogenesis. The relation of S100A8/A9 and sRAGE with ventricular arrhythmias and sudden cardiac death risk has not been previously assessed.

Purpose

Purpose of the study was to investigate whether S100A8/A9 and sRAGE serum blood levels of patients (pts) with systolic heart failure are related to the occurrence of life-threatening ventricular tachyarrhythmias.

Patients and methods

We studied 60 pts with clinically stable heart failure due to coronary artery disease (n=37) and dilated cardiomyopathy (n=23), all with a chronically implanted ICD for primary (n=43) or secondary (n=16) sudden death prevention, all in sinus rhythm. Their mean age (±1 SE) was 62±2 years, NYHA class I-II, mean LVEF 28±1%, Nt-pro-BNP 893±85 pg/dl. Blood was drawn at study initiation for S100A8/A9 and sRAGE assessment (ELISA, R&D Systems). They all were systematically followed-up for 4 years regarding the occurrence of fast ventricular tachyarrhythmias (>180 bpm) necessitating antiarrhythmic intervention through the ICD.

Results

S100A8/A9 and sRAGE levels were 16±1.6 ng/ml and 1076±99 pg/ml respectively. S100A8/A9 levels were lower than in normal controls, while sRAGE levels were within normal limits. During the 4-year follow-up period, 39 pts had an uneventful course (Group I), while 16 pts exhibited fast ventricular tachyarrhythmic episodes necessitating ICD activation (anti-tachycardia pacing or shock, Group II). Three pts died of pump failure and 2 pts of non-cardiac causes. No differences were observed between Group I and Group II pts regarding mean NYHA class, Nt-pro-BNP levels. Group II patients had significantly lower LVEF as well as S100A8/A9 serum levels relative to pts without ventricular arrhythmias (LVEF: 30±1.2 vs, 25±1.3%, p<0.05, S1OOA8/A9: 18.9±2.2 vs 11.8±1.5 ng/ml, p<0.05), while no difference was observed between Groups regarding sRAGE levels 1097±101 1105±239 pg/ml, p:NS). S100A8/A9 levels were not related significantly to LVEF (r:-21, p=0.13).

Conclusion

S100A8/A9 protein levels are reduced in pts with stable HF and an implanted ICD. They are even lower among pts with rapid ventricular tachyarrhythmias occurring during follow-up. This finding implies that S100A8/A9 may constitute a biomarker of increased sudden cardiac death risk in HF, in addition to reduced LVEF.

Effects of serial levosimendan infusions on left ventricular performance and plasma biomarkers of myocardial injury and neurohormonal and immune activation in patients with advanced heart failure

BACKGROUND

Levosimendan is a novel inodilator that improves central haemodynamics and symptoms of patients with decompensated chronic heart failure. The role, however, of repeated levosimendan infusions in the management of these patients has not yet been properly assessed.

PURPOSE

This randomised placebo-controlled trial investigated the effects of serial levosimendan infusions on cardiac geometry and function, and on biomarkers of myocardial injury and neurohormonal and immune activation (troponin T, N-terminal B-type natriuretic pro-peptide (NT-proBNP), C reactive protein (CRP) and interleukin (IL) 6) in patients with advanced heart failure.

METHODS

25 patients with decompensated chronic heart failure were randomised (2:1) to receive five serial 24-h infusions (every 3 weeks) of either levosimendan (n = 17) or placebo (n = 8), and were evaluated echocardiographically and biochemically before and after each drug infusion and 30 days after the final infusion.

RESULTS

Following treatment, cardiac end-systolic and end-diastolic dimension and volume indices were significantly reduced only in the levosimendan-treated patients (p<0.01). A significant decrease in NT-proBNP (p<0.01), high-sensitivity CRP (p<0.01) and plasma IL6 (p = 0.05) was also observed in the levosimendan group, whereas these markers remained unchanged in the placebo group; similar changes were observed after each drug infusion. Although the number of patients with a positive troponin T (>or=0.01 ng/ml) was not different between the two groups at baseline, it was significantly higher in the placebo-treated group during the final evaluation (p<0.05).

CONCLUSION

Serial levosimendan treatments improved left ventricular performance and modulated neurohormonal and immune activation beneficially in patients with advanced heart failure, without increasing myocardial injury.

Synthesis, binding studies and in vivo biological evaluation of novel non-peptide antihypertensive analogues

AT(1) antagonists (SARTANs) constitute the last generation of drugs for the treatment of hypertension, designed and synthesized to mimic the C-terminal segment of the vasoconstrictive hormone angiotensin II (AngII). They exert their action by blocking the binding of AngII on the AT(1) receptor. Up to date eight AT(1) antagonists have been approved for the regulation of high blood pressure. Although these molecules share common structural features and are designed to act under the same mechanism, they have differences in their pharmacological profiles and antihypertensive efficacy. Thus, there is still a need for novel analogues with better pharmacological and financial profiles. An example of a novel synthetic non peptide AT(1) antagonist which devoids the classical template of SARTANs is MM1. In vivo studies showed that MMK molecules, which fall in the same class of MM1, had a significant antihypertensive (40-80% compared to the drug losartan) activity. However, in vitro affinity studies showed that losartan has considerably higher affinity. The theoretical docking studies showed that MM1 acts on the same site of the receptor as losartan. They exert hydrophobic interactions with amino acid Val108 of the third helix of the AT(1) receptor and other hydrophobic amino acids in spatial vicinity. In addition, losartan favours multiple hydrogen bondings between its tetrazole group with Lys199. These additional interactions may in part explain its higher in vitro binding affinity.

Design and synthesis of novel antihypertensive drugs

AT1 antagonists constitute a new generation of drugs for the treatment of hypertension and are designed and synthesized to mimic the C-terminal segment of Angiotensin II (Ang II) and to block its binding action on AT1 receptor. For this reason, the conformational analysis of Ang II and its derivatives as well as the AT1 antagonists belonging to SARTANs class of molecules were studied. Such studies offer the possibility to reveal the stereoelectronic factors responsible for bioactivity of AT1 antagonists and to design and synthesize new analogues with better pharmacological and financial profiles. An example of a novel synthetic non-peptide molecule is given which mimics the His(6)-Pro(7)-Phe(8) part of Ang II and is based on the (S)-pyroglutamic acid.

Conformational and biological studies for a pair of novel synthetic AT1 antagonists: stereoelectronic requirements for antihypertensive efficacy

One of the major systems which interferes with the disease of hypertension, is the Renin Angiotensin Aldosterone System (RAS). The octapeptide hormone angiotensin II is the active product of RAS which causes vasoconstriction when binds to the AT(1) receptor. In the last years, there has been a development of drugs which block the Angiotensin II from binding the AT(1) receptor and are called AT(1) antagonists. In an effort to comprehend their stereoelectronic features, a study has been initiated to compare the conformational properties of drugs already marketed for the treatment of hypertension and others which are designed and synthesized in our laboratory possessing structural characteristics necessary for antihypertensive activity. In this study, two synthetic non-peptide AT(1) antagonists, are structurally elucidated and their conformational properties and bioactivity are compared to the prototype and first approved drug of this category in the market; losartan (trade name: COZAAR).

Design, synthesis and biological evaluation of cyclic angiotensin II analogues with 3,5 side-chain bridges. Role of C-terminal aromatic residue and ring cluster for activity and implications in the drug design of AT1 non-peptide antagonists

The novel amide linked angiotensin II (ANG II) cyclic analogues: gamma, epsilon -cyclo(3, 5)-[Sar(1)-Glu(3)-Lys(5)-Ile(8)] ANG II (I) and gamma, epsilon -cyclo(3, 5)-[Sar(1)-Glu(3)-Lys(5)-Phe(8)] ANG II (II) have been designed, synthesized and bioassayed in anesthetized rabbits in order to unravel structural ring cluster characteristics important for receptor activation. Analogue I with Ile at position 8 was an inhibitor of Angiotensin II while analogue II with Phe at position 8 was found to be an agonist. Similar results were reported for cyclic compounds that have reversed the linking between positions 3 and 5. The overall results show that positions 3 and 5 do not govern the biological activity of the synthetic analogues. It also appears that the aromatic ring cluster (Tyr-His-Phe) in agonist peptides is an essential stereo-electronic feature for Angiotensin II to exert its biological activity. A non-peptide mimetic of ANG II, 1-[2'-[(N-benzyl)tetrazol-5-yl]biphenyl-4-yl]methyl]-2-hydroxymethylbenzimidazole (BZI8) has been designed and synthesized. This molecule is more rigid and much less active than AT(1) non-peptide mimetic losartan probably because it lacks to mimic the orientation of tetrazole and the pharmacophore segments of butyl chain and imidazole ring.

Ablation therapy of type I atrial flutter may eradicate paroxysmal atrial fibrillation

In patients with paroxysms of atrial fibrillation preceded by episodes of atrial flutter on Holter monitoring, eradication of the flutter circuit may also abolish the episodes of atrial fibrillation. At electrophysiology study, these patients are identified by documentation of simultaneous flutter of the right atrium and fibrillation of the left atrium.