GLP-1 receptor agonists-SGLT-2 inhibitors combination therapy and cardiovascular events after acute myocardial infarction: an observational study in patients with type 2 diabetes

BACKGROUND

Few studies explored the effect of the combination of glucose sodium-cotransporter-2 inhibitors (SGLT-2i) and glucagon-like peptide-1 receptor agonists (GLP-1RA) on the incidence of cardiovascular events in patients with type 2 diabetes (T2D) and acute myocardial infarction (AMI).

METHODS

We recruited patients with T2D and AMI undergoing percutaneous coronary intervention, treated with either SGLT-2i or GLP-1RA for at least 3 months before hospitalization. Subjects with HbA1c < 7% at admission were considered in good glycemic control and maintained the same glucose-lowering regimen, while those with poor glycemic control (HbA1c ≥ 7%), at admission or during follow-up, were prescribed either a SGLT-2i or a GLP-1RA to obtain a SGLT-2i/GLP-1RA combination therapy. The primary outcome was the incidence of major adverse cardiovascular events (MACE) defined as cardiovascular death, re-acute coronary syndrome, and heart failure related to AMI during a 2-year follow-up. After 3 months, the myocardial salvage index (MSI) was assessed by single-photon emission computed tomography.

FINDINGS

Of the 537 subjects screened, 443 completed the follow-up. Of these, 99 were treated with SGLT-2i, 130 with GLP-1RA, and 214 with their combination. The incidence of MACE was lower in the combination therapy group compared with both SGLT-2i and GLP-1RA treated patients, as assessed by multivariable Cox regression analysis adjusted for cardiovascular risk factors (HR = 0.154, 95% CI 0.038-0.622, P = 0.009 vs GLP-1RA and HR = 0.170, 95% CI 0.046-0.633, P = 0.008 vs SGLT-2i). The MSI and the proportion of patients with MSI > 50% was higher in the SGLT-2i/GLP-1RA group compared with both SGLT-2i and GLP-1RA groups.

INTERPRETATION

The combination of SGLT-2i and GLP-1RA is associated with a reduced incidence of cardiovascular events in patients with T2D and AMI compared with either drug used alone, with a significant effect also on peri-infarcted myocardial rescue in patients without a second event. Trial registraition ClinicalTrials.gov ID: NCT06017544.

Evidence of an anti-inflammatory effect of PCSK9 inhibitors within the human atherosclerotic plaque

BACKGROUND AND AIMS

Preclinical evidence suggests that proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors hold anti-inflammatory properties independently of their ability to lower LDL-cholesterol (C). However, whether PCSK9 inhibitors exert anti-inflammatory effects within the atherosclerotic plaque in humans is unknown. We explored the impact of PCSK9 inhibitors, used as monotherapy, compared with other lipid-lowering drugs (oLLD) on the expression of inflammatory markers within the plaque, assessing also the subsequent incidence of cardiovascular events.

METHODS

In an observational study, we recruited 645 patients on stable therapy for at least six months and undergoing carotid endarterectomy, categorizing patients according to the use of PCSK9 inhibitors only (n = 159) or oLLD (n = 486). We evaluated the expression of NLRP3, caspase-1, IL-1β, TNFα, NF-kB, PCSK9, SIRT3, CD68, MMP-9, and collagen within the plaques in the two groups through immunohistochemistry, ELISA, or immunoblot. A composite outcome including non-fatal myocardial infarction, non-fatal stroke, and all-cause mortality was assessed during a 678 ± 120 days follow-up after the procedure.

RESULTS

Patients treated with PCSK9 inhibitors had a lower expression of pro-inflammatory proteins and a higher abundance of SIRT3 and collagen within the plaque, a result obtained despite comparable levels of circulating hs-CRP and observed also in LDL-C-matched subgroups with LDL-C levels <100 mg/dL. Patients treated with PCSK9 inhibitors showed a decreased risk of developing the outcome compared with patients on oLLD, also after adjustment for multiple variables including LDL-C (adjusted hazard ratio 0.262; 95% CI 0.131-0.524; p < 0.001). The expression of PCSK9 correlated positively with that of pro-inflammatory proteins, which burden was associated with a higher risk of developing the outcome, independently of the therapeutic regimen.

CONCLUSIONS

The use of PCSK9 inhibitors is accompanied by a beneficial remodelling of the inflammatory burden within the human atheroma, an effect possibly or partly independent of their LDL-C lowering ability. This phenomenon might provide an additional cardiovascular benefit.

SGLT-2 inhibitors and in-stent restenosis-related events after acute myocardial infarction: an observational study in patients with type 2 diabetes

BACKGROUND

No study evaluated the incidence of intra-stent restenosis (ISR)-related events in patients with type 2 diabetes (T2DM) and acute myocardial infarction (AMI) treated or not with sodium/glucose cotransporter 2 inhibitors (SGLT2i).

METHODS

We recruited 377 patients with T2DM and AMI undergoing percutaneous coronary intervention (PCI). Among them, 177 T2DM were treated with SGLT2 inhibitors before PCI. The primary outcome was major adverse cardiovascular events (MACE) defined as cardiac death, re-infarction, and heart failure related to ISR. In patients without ISR, minimal lumen area and minimal lumen diameter were assessed by coronary CT-angiography at 1-year follow-up.

RESULTS

Glycemic control was similar in SGLT2i-treated patients and never SGLT2i-users. The incidence of ISR-related MACE was higher in never SGLT2i-users compared with SGLT2i-treated patients, an effect independent of glycemic status (HR = 0.418, 95% CI = 0.241-0.725, P = 0.002) and observed also in the subgroup of patients with HbA1c < 7% (HR = 0.393, 95% CI = 0.157-0.984, P = 0.027). In patients without the event, the stent patency was greater in SGLT2i-treated patients compared with never SGLT2i-users at 1-year follow-up.

CONCLUSIONS

SGLT2i treatment in T2DM is associated with a reduced incidence of ISR-related events, independently of glycemic control.

Radical Nephroureterectomy Tetrafecta: A Proposal Reporting Surgical Strategy Quality at Surgery

Background

Standardized methods for reporting surgical quality have been described for all the major urological procedures apart from radical nephroureterectomy (RNU).

Objective

To propose a tetrafecta criterion for assessing the quality of RNU based on a consensus panel within the Young Association of Urology (YAU) Urothelial Group, and to test the impact of this tetrafecta in a multicenter, large contemporary cohort of patients treated with RNU for upper tract urothelial carcinoma (UTUC).

Design, setting, and participants

This was a retrospective analysis of 1765 patients with UTUC treated between 2000 and 2021.

Outcome measurements and statistical analysis

We interviewed the YAU Urothelial Group to propose and score a list of items to be included in the “RNU-fecta.” A ranking was generated for the criteria with the highest sum score. These criteria were applied to a large multicenter cohort of patients. Kaplan-Meier curves were built to evaluate differences in overall survival (OS) rates between groups, and a multivariable logistic regression model was used to find the predictors of achieving the RNU tetrafecta.

Results and limitations

The criteria with the highest score included three surgical items such as negative soft tissue surgical margins, bladder cuff excision, lymph node dissection according to guideline recommendations, and one oncological item defined by the absence of any recurrence in ≤12 mo. These items formed the RNU tetrafecta. Within a median follow-up of 30 mo, 52.6% of patients achieved the RNU tetrafecta. The 5-yr OS rates were significantly higher for patients achieving tetrafecta than for their counterparts (76% vs 51%). Younger age, lower body mass index, and robotic approach were found to be independent predictors of tetrafecta achievement. Conversely, a higher Eastern Cooperative Oncology Group score, higher clinical stage, and bladder cancer history were inversely associated with tetrafecta.

Conclusions

Herein, we present a “tetrafecta” composite endpoint that may serve as a potential tool to assess the overall quality of the RNU procedure. Pending external validation, this tool could allow a comparison between surgical series and may be useful for assessing the learning curve of the procedure as well as for evaluating the impact of new technologies in the field.

Patient summary

In this study, a tetrafecta criterion was developed for assessing the surgical quality of radical nephroureterectomy in patients with upper tract urothelial carcinoma. Patients who achieved tetrafecta had higher 5-yr overall survival rates than those who did not.

[Treatment of acute myocardial infarction in 2017]

Acute myocardial infarction is a clinical cardiac emergency associated with potential and substantial morbidity and mortality. This disorder is triggered by an acute coronary syndrome caused by episodes of plaque ulceration, fissuration, or rupture with subsequent production of thrombogenic material and intravascular thrombus formation. The presence or absence of ST-segment elevation on the ECG defines the two main clinical spectrum of ST-segment elevation or non-ST-segment elevation myocardial infarction. In the last three decades, pharmacological and interventional management as well as in-hospital care have dramatically improved. Recent advances in antithrombotic strategies, percutaneous access (radial versus femoral), timing of revascularization, new generation coronary stents, lipid profile management, and cardiac rehabilitation programs at discharge have lead the European Task Force on ST-Elevation Myocardial Infarction to revise the 2012 guidelines and to release, in the current year, an updated version.

Thrombus aspiration in hyperglycemic ST-elevation myocardial infarction (STEMI) patients: clinical outcomes at 1-year follow-up

Objectives

We evaluate whether the thrombus aspiration (TA) before primary percutaneous coronary intervention (PPCI) may improve STEMI outcomes in hyperglycemic patients.

Background

The management of hyperglycemic patients during STEMI is unclear.

Methods

We undertook an observational cohort study of 3166 first STEMI. Patients were grouped on the basis of whether they received TA or not. Moreover, among these patients we selected a subgroup of STEMI patients with hyperglycemia during the event (glycaemia > 140 mg/dl). The endpoint at 1 year included all-cause mortality, cardiac mortality and re-hospitalization for coronary disease, heart failure and stroke.

Results

One-thousand STEMI patients undergoing PPCI to plus TA (TA-group) and 1504 STEMI patients treated with PPCI alone (no-TA group) completed the study. In overall study-population, Kaplan–Meier-analysis demonstrated no significant difference in mortality rates between patients with and without TA (P = 0.065). After multivariate Cox-analysis (HR: 0.94, 95% CI 0.641–1.383) and the addition of propensity matching (HR: 0.86 95% CI 0.412–1.798) TA was still not associated with decreased mortality. By contrast, in hyperglycemic subgroup STEMI patients (TA-group, n = 331; no-TA group, n = 566), Kaplan–Meier-analysis demonstrated a significantly lower mortality (P = 0.019) in TA-group than the no-TA group. After multivariate Cox-analysis (HR: 0.64, 95% CI 0.379–0.963) and the addition of propensity matching (HR: 0.54, 95% CI 0.294–0.984) TA was still associated with decreased mortality.

Conclusions

TA was not associated with lower mortality in PPCI for STEMI when used in our large all-comer cohort. Conversely, TA during PPCI for STEMI reduces clinical outcomes in hyperglycemic patients.

Trial registration NCT02817542. 25th, June 2016

Electronic supplementary material

The online version of this article (10.1186/s12933-018-0795-8) contains supplementary material, which is available to authorized users.

Sirtuin 6 expression and inflammatory activity in diabetic atherosclerotic plaques: effects of incretin treatment

The role of sirtuin 6 (SIRT6) in atherosclerotic progression of diabetic patients is unknown. We evaluated SIRT6 expression and the effect of incretin-based therapies in carotid plaques of asymptomatic diabetic and nondiabetic patients. Plaques were obtained from 52 type 2 diabetic and 30 nondiabetic patients undergoing carotid endarterectomy. Twenty-two diabetic patients were treated with drugs that work on the incretin system, GLP-1 receptor agonists, and dipeptidyl peptidase-4 inhibitors for 26 ± 8 months before undergoing the endarterectomy. Compared with nondiabetic plaques, diabetic plaques had more inflammation and oxidative stress, along with a lesser SIRT6 expression and collagen content. Compared with non-GLP-1 therapy-treated plaques, GLP-1 therapy-treated plaques presented greater SIRT6 expression and collagen content, and less inflammation and oxidative stress, indicating a more stable plaque phenotype. These results were supported by in vitro observations on endothelial progenitor cells (EPCs) and endothelial cells (ECs). Indeed, both EPCs and ECs treated with high glucose (25 mmol/L) in the presence of GLP-1 (100 nmol/L liraglutide) presented a greater SIRT6 and lower nuclear factor-κB expression compared with cells treated only with high glucose. These findings establish the involvement of SIRT6 in the inflammatory pathways of diabetic atherosclerotic lesions and suggest its possible positive modulation by incretin, the effect of which is associated with morphological and compositional characteristics of a potential stable plaque phenotype.

Trace elements in scalp hair of children living in differing environmental contexts in Sicily (Italy)

We present here data about trace elements in human scalp hair samples to test whether they are valuable to reflect environmental exposure and contamination by trace elements. The study compares contents of trace elements in scalp hair from a total of 336 children, aged 11-13 years old, living in various geographical areas of Sicily (southern Italy) characterized by differing environmental conditions. Nineteen elements (Al, As, Ba, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, Pb, Rb, Sb, Se, Sr, U, V and Zn) were determined by inductively coupled plasma mass spectrometry (ICP-MS). Coverage intervals (CI) formulated by the elemental composition of hair samples from the Palermo subjects were compared with the median content of hair from children living in the other study areas. Statistical analysis showed that Al, Ba, Sr and Zn concentrations differed significantly between gender, higher concentrations being observed in girls' hair. Children living close to the volcanic area had higher concentrations of As, Cr, Mn, Ni, Rb, Sb, U, V and Zn. Those living in an area with several old quarries had higher levels of Al, As, Pb, Rb and U. The hair of children living near the Pace del Mela industrial area contained higher levels of As, Ba, Mn, Pb, Rb, Sr and U. Linear discriminant analysis (LDA) between Palermo and the other sites allowed to better assess which variables contribute towards differentiating the groups. Our observations suggest that human hair can be used to monitor exposure to several metals, provided that sampling and analytical procedures, together with statistical treatment of data, are carried out according to standardized protocols.

Peri-procedural tight glycemic control during early percutaneous coronary intervention is associated with a lower rate of in-stent restenosis in patients with acute ST-elevation myocardial infarction

OBJECTIVE

We examined the effects of peri-procedural intensive glycemic control (IGC) during early percutaneous coronary intervention (PCI) on restenosis rate in hyperglycemic patients with ST-segment elevation myocardial infarction (STEMI).

RESEARCH DESIGN AND METHODS

A total of 165 hyperglycemic patients (glucose ≥ 140 mg/dl) with first STEMI undergoing PCI were studied. Patients were randomized to IGC for almost 24 h after PCI (n = 82; glucose, 80-140 mg/dl) followed by multidose sc insulin during the hospital stay or conventional glycemic control (CGC; n = 83; glucose, 180-200 mg/dl) followed by conventional therapy. Coronary angiography was performed at study entry and at 6-month follow-up. Blood samples for glycemia, hemoglobin A1c, inflammatory markers (C-reactive protein and TNF-α), monocyte chemoattractant-protein-1, and oxidative stress (nitrotyrosine) were collected immediately before and 24 h, 30 and 180 d after PCI.

RESULTS

After insulin infusion, mean plasma glucose during the peri-procedural period was greater in the CGC group than in the IGC group (CGC, 191 ± 15 mg/dl; IGC, 145 ± 35 mg/dl; P < 0.001). After the insulin infusion period, the levels of markers of oxidative stress (nitrotyrosine), inflammation (C-reactive protein, TNF-α), and monocyte chemoattractant-protein-1 were significantly higher in CGC patients compared with IGC patients. Moreover, ICG during PCI reduces restenosis by half (48 and 24%) at 6 months. During follow-up, there was no difference in mortality rates, glucose, inflammatory and oxidative stress markers among the groups. In-stent restenosis was positively associated with mean plasma glucose levels as well as oxidative stress and inflammatory markers during the insulin infusion period.

CONCLUSIONS

In hyperglycemic patients with STEMI, optimal peri-procedural glycemic control by reducing oxidative stress and inflammation may improve the outcome after PCI.

Correlations between progression of coronary artery disease and circulating endothelial progenitor cells

The pathophysiology of coronary artery disease (CAD) progression is not well understood. Endothelial progenitor cells (EPCs) may have an important role. In the present observational cohort study we assessed the number of circulating EPCs in 136 patients undergoing elective percutaneous coronary intervention and who had at least one major epicardial vessel with a nonsignificant stenosis [<50% diameter stenosis (DS)], and the relationship between plasma EPC levels and the 24-mo progression of the nonsignificant coronary artery lesion. The following cell populations were analyzed: CD34(+), CD133(+), CD34(+)/KDR(+), CD34(+)/VE cadherin(+), and endothelial cell colony-forming units (CFU-ECs). Progression was defined as a >15% DS increase of the objective vessel at follow-up. At 24 mo, 57 patients (42%) experienced significant progression. Independent predictors of disease progression were LDL cholesterol > 100 mg/dl (OR=1.03; 95% CI 1.01-1.04; P=0.001), low plasma levels of CFU-ECs (OR=3.99; 95% CI 1.54-10.37; P=0.005), and male sex (OR=3.42; 95% CI 1.15-10.22; P=0.027). Circulating levels of EPCs are significantly lower in patients with angiographic CAD progression.

Comparison of coronary drug-eluting stents versus coronary artery bypass grafting in patients with diabetes mellitus

We compared 1-year outcome after drug-eluting stent (DES) implantation with off-pump bypass grafing (OPCABG) in patients with type 2 diabetes mellitus and multivessel coronary artery disease involving the proximal segment of the left anterior descending coronary artery. All consecutive diabetic patients treated by DES (DES group) or OPCABG (CABG group) in our institution from April 2002 to December 2004 because of de novo coronary lesions were included. Patients in the CABG group (n = 149) were older and had a higher rate of 3-vessel disease than those in the DES group (n = 69). At 12 months, major adverse cardiac and cerebrovascular events occurred in 29% of the DES group and 20.5% of the CABG group (unadjusted analysis, odds ratio 1.20, 95% confidence interval [CI] 0.93 to 1.54, p = 0.17). After propensity score analysis, adjusting for baseline differences between the 2 cohorts, DESs increased the risk of 12-month major adverse cardiac and cerebrovascular events (hazard ratio 1.88, 95% CI 1.09 to 3.02, p = 0.020). This was due to the higher rate for repeat revascularization in the DES group (19% vs 5%, odds ratio 2.05, 95% CI 1.12 to 3.75, p = 0.001). In contrast, there was no difference in the rate of the composite end points of death, myocardial infarction, and stroke (DES group 13%, CABG group 12%; adjusted analysis, hazard ratio 0.80, 95% CI 0.80 to 1.35, p = 0.40). In conclusion, at 1 year in diabetic patients with multivessel coronary artery disease involving the proximal left anterior descending coronary artery, the advantage of OPCABG over DES implantation seems to be limited at a lower rate of repeat revascularization. No difference seems to exist in the rate of death, stroke, and myocardial infarction.

Renal Insufficiency Following Contrast Media Administration Trial (REMEDIAL): a randomized comparison of 3 preventive strategies

BACKGROUND

Volume supplementation by saline infusion combined with N-acetylcysteine (NAC) represents an effective strategy to prevent contrast agent-induced nephrotoxicity (CIN). Preliminary data support the concept that sodium bicarbonate and ascorbic acid also may be effective in preventing CIN.

METHODS AND RESULTS

Three hundred twenty-six consecutive patients with chronic kidney disease, referred to our institutions for coronary and/or peripheral procedures, were randomly assigned to prophylactic administration of 0.9% saline infusion plus NAC (n=111), sodium bicarbonate infusion plus NAC (n=108), and 0.9% saline plus ascorbic acid plus NAC (n=107). All enrolled patients had serum creatinine > or = 2.0 mg/dL and/or estimated glomerular filtration rate < 40 mL x min(-1) x 1.73 m(-2). Contrast nephropathy risk score was calculated in each patient. In all cases, iodixanol (an iso-osmolar, nonionic contrast agent) was administered. The primary end point was an increase of > or = 25% in the creatinine concentration 48 hours after the procedure (CIN). The amount of contrast media administered (179+/-102, 169+/-92, and 169+/-94 mL, respectively; P=0.69) and risk scores (9.1+/-3.4, 9.5+/-3.6, and 9.3+/-3.6; P=0.21) were similar in the 3 groups. CIN occurred in 11 of 111 patients (9.9%) in the saline plus NAC group, in 2 of 108 (1.9%) in the bicarbonate plus NAC group (P=0.019 by Fisher exact test versus saline plus NAC group), and in 11 of 107 (10.3%) in the saline plus ascorbic acid plus NAC group (P=1.00 versus saline plus NAC group).

CONCLUSIONS

The strategy of volume supplementation by sodium bicarbonate plus NAC seems to be superior to the combination of normal saline with NAC alone or with the addition of ascorbic acid in preventing CIN in patients at medium to high risk.

Renal Insufficiency Following Contrast Media Administration Trial (REMEDIAL): a randomized comparison of 3 preventive strategies

BACKGROUND

Volume supplementation by saline infusion combined with N-acetylcysteine (NAC) represents an effective strategy to prevent contrast agent-induced nephrotoxicity (CIN). Preliminary data support the concept that sodium bicarbonate and ascorbic acid also may be effective in preventing CIN.

METHODS AND RESULTS

Three hundred twenty-six consecutive patients with chronic kidney disease, referred to our institutions for coronary and/or peripheral procedures, were randomly assigned to prophylactic administration of 0.9% saline infusion plus NAC (n=111), sodium bicarbonate infusion plus NAC (n=108), and 0.9% saline plus ascorbic acid plus NAC (n=107). All enrolled patients had serum creatinine > or = 2.0 mg/dL and/or estimated glomerular filtration rate < 40 mL x min(-1) x 1.73 m(-2). Contrast nephropathy risk score was calculated in each patient. In all cases, iodixanol (an iso-osmolar, nonionic contrast agent) was administered. The primary end point was an increase of > or = 25% in the creatinine concentration 48 hours after the procedure (CIN). The amount of contrast media administered (179+/-102, 169+/-92, and 169+/-94 mL, respectively; P=0.69) and risk scores (9.1+/-3.4, 9.5+/-3.6, and 9.3+/-3.6; P=0.21) were similar in the 3 groups. CIN occurred in 11 of 111 patients (9.9%) in the saline plus NAC group, in 2 of 108 (1.9%) in the bicarbonate plus NAC group (P=0.019 by Fisher exact test versus saline plus NAC group), and in 11 of 107 (10.3%) in the saline plus ascorbic acid plus NAC group (P=1.00 versus saline plus NAC group).

CONCLUSIONS

The strategy of volume supplementation by sodium bicarbonate plus NAC seems to be superior to the combination of normal saline with NAC alone or with the addition of ascorbic acid in preventing CIN in patients at medium to high risk.

Histological findings of a surgically excised myopic choroidal neovascular membrane after photodynamic therapy. A case report

BACKGROUND

The authors describe a myopic choroidal neovascular membrane excised 4 months after photodynamic therapy (PDT).

METHODS

A 68-year-old woman with classic choroidal neovascularization (CNV) due to pathologic myopia underwent PDT with verteporfin in the left eye. Four months after treatment a full-thickness macular hole was diagnosed in the same eye and the patient underwent vitrectomy with submacular membranectomy. The subfoveal membrane was studied by light microscopy and immunohistochemical techniques.

RESULTS

Light microscopy showed a thin fibrovascular membrane covered by residual retinal pigment epithelium. The membrane contained homogeneous matrix with small collagen bundles, fibroblasts and small blood vessels. The distribution of blood vessels was nonuniform: extravasated red blood cells, macrophages and other inflammatory elements were not present in the fibrous matrix. Endothelial cells were highlighted by CD34 immunostaining and did not show any significant alteration. There was no evidence of inflammatory cells or thrombosis inside vascular lumina.

CONCLUSIONS

Histologic examination of the neovascular membrane showed features similar to those of surgically excised myopic CNV without PDT treatment. Our findings suggest that PDT-induced occlusion is temporary. Fluorescein leakage from CNV after a single PDT treatment can be considered as an sign of blood vessel regrowth or recanalization indicating that multiple treatments are necessary.

Induction of tissue factor in the arterial wall during recurrent thrombus formation

OBJECTIVE

Tissue factor (TF) is normally expressed at low levels in the media of blood vessels, but it is readily induced after vessel injury. It is not known whether vascular damage per se or thrombus formation is responsible for this phenomenon.

METHODS AND RESULTS

Cyclic flow variations (CFVs), attributable to recurrent thrombus formation, were induced in stenotic rabbit carotid arteries with endothelial injury. CFVs were observed for 30 minutes and 2, 4, and 8 hours in different groups of animals. Another group of rabbits pretreated with hirudin before inducing arterial damage to inhibit thrombus formation was observed for 8 hours. Arterial sections were immunostained for TF. Undamaged arteries served as controls. In additional rabbits, in situ hybridization experiments were performed. No TF expression was observed in the media of control vessels, whereas a progressive increase in TF mRNA and protein expression was observed in carotid arteries as CFVs progressed. No increase in TF expression was observed in animals pretreated with hirudin. In vitro experiments demonstrated that TF mRNA is induced in smooth muscle cells stimulated with activated platelets as well as with some platelet-derived mediators.

CONCLUSIONS

This phenomenon may contribute to sustain intravascular thrombus formation after the initial thrombogenic stimulus.

Percutaneous treatment of early occlusion of a complex arterial coronary graft: a case report

The internal mammary arteries are now widely used for surgical myocardial revascularization. Because of its excellent long-term patency rates, re-do surgery is rarely requested and transluminal percutaneous angioplasty of these arterial grafts is still relatively infrequent. This procedure is performed mainly at the distal anastomotic site but also at the origin of the vessel from the subclavian artery, frequently just to treat a local traumatic dissection due to the catheter. We here report the case of a successful angioplasty and stenting of the body of the graft for an early total occlusion of a complex, bifurcated arterial bypass to the left coronary system.

Expression of exogenous tissue factor pathway inhibitor in vivo suppresses thrombus formation in injured rabbit carotid arteries

OBJECTIVES

The aim of the present study was to test the hypothesis that retrovirus-mediated in vivo tissue factor pathway inhibitor (TFPI) gene transfer to the arterial wall would efficiently inhibit thrombosis without causing significant changes in systemic hemostatic variables.

BACKGROUND

Acute coronary syndromes (unstable angina and acute myocardial infarction) are usually caused by atherosclerotic plaque rupture, with consequent activation of the coagulation cascade and circulating platelets. Tissue factor (TF) exposure represents an early event in this pathophysiologic sequence, leading to activation of the extrinsic coagulation pathway and thrombin formation. Tissue factor pathway inhibitor is a naturally occurring inhibitor of the extrinsic pathway.

METHODS

In the present study, the gene coding for rabbit TFPI was inserted in a retroviral vector under control of a tetracycline-inducible promoter. Replication-defective, infectious, recombinant retroviruses were used to transfect rabbit carotid arteries with either TFPI or a reporter gene--green fluorescent protein (GFP).

RESULTS

Retroviral-mediated arterial gene transfer of TFPI resulted in potent inhibition of intravascular thrombus formation in stenotic and injured rabbit carotid arteries, whereas transfection of the contralateral carotid artery with GFP had no effect on thrombosis. No significant changes in systemic hemostatic variables (prothrombin time and partial thromboplastin time) were observed when thrombosis was inhibited.

CONCLUSIONS

These data suggest that retroviral-mediated transfection of the arterial wall with TFPI might represent an attractive approach for the treatment of thrombotic disorders.

Effects of recombinant active site-blocked activated factor VII in rabbit models of carotid stenosis and myocardial infarction

We tested the effects of human recombinant active site-blocked activated factor VII (rFVIIai) in a rabbit model of carotid artery thrombosis. Cyclic flow variations (CFVs), due to recurrent thrombus formation, were obtained in stenotic rabbit carotid arteries with endothelial injury. After 30 min of CFV, the animals received rFVIIai. If CFVs were abolished, animals were observed for 30 additional minutes, after which human recombinant activated factor VII was infused into the carotid artery to determine whether it could displace rFVIIai from tissue factor (TF), thus restoring CFV. An additional group of animals received rFVIIai to determine its duration of action. Recombinant FVIIai abolished CFVs in 8 of 9 rabbits (P < 0.01). This effect was reversible, as rFVIIa administration restored CFVs in all animals. A further study was initiated to assess whether TF-dependent reductions in coronary blood flow might contribute to the occurrence of myocardial injury during postischaemic reperfusion of rabbit hearts. Recombinant FVIIai resulted in significant reductions in both infarct size and no-reflow area, while rFVIIa produced a significant increase in both infarct size and no-reflow area. These data suggest that rFVIIai might be beneficial in patients with acute myocardial infarction undergoing reperfusion therapies.

Clinical use of a topical carbonic anhydrase inhibitor in patients affected by chronic simple glaucoma

The aim of this study is to evaluate the ocular hypotensive efficacy of a topical carbonic anhydrase inhibitor (dorzolamide) in primary open-angle glaucoma patients, administered alone or in association with beta-blockers or with beta-blockers and miotics, in a one-year follow-up.

The role of class I and class II HLA antigens in primary open angle glaucoma (POAG)

Several clinical and epidemiological studies have shown the role of genetic factors in the pathogenesis of primary open angle glaucoma (POAG). In this study, 30 patients affected by this disease were tissue-typed for HLA Class I and Class II antigens. The results pointed up an increased incidence of some antigens and, particularly, a statistically significant association with DQ1 and DR11 alleles.

Antithrombotic effects of recombinant human, active site-blocked factor VIIa in a rabbit model of recurrent arterial thrombosis

The extrinsic coagulation pathway is activated when circulating factor VII (FVII) gains access to tissue factor (TF) exposed as a consequence of vascular injury. Increasing evidence indicates that this TF-dependent activation of the coagulation plays an important role in the pathophysiology of intravascular thrombus formation. In the present study, we tested the effects of recombinant human, active site-blocked activated FVII (FVIIai) in a rabbit model of carotid artery thrombosis. Cyclic flow variations (CFVs), due to recurrent thrombus formation, were obtained in stenotic rabbit carotid arteries with endothelial injury. Carotid blood flow velocity was measured by a Doppler flow probe. After 30 minutes of CFVs, the animals received FVIIai (100 microg x kg(-1) x min(-1) intracarotid infusion for 10 minutes, n=9). If CFVs were abolished, animals were followed for 30 additional minutes, after which recombinant human activated FVII (FVIIa) was infused into the carotid artery (100 microg x kg(-1) x min(-1) for 10 minutes) to determine whether FVIIai could be displaced from TF by FVIIa, thus restoring CFVs. To establish the duration of action of FVIIai, an additional group of animals received FVIIai at the same dose as above, and after CFVs were inhibited, they were followed until CFVs were restored or for up to 6 hours. To determine whether CFVs could be restored by epinephrine after their abolition with FVIIai, increasing doses of epinephrine were administered to a third group of 6 animals. FVIIai abolished CFVs in 8 of 9 rabbits (P<.01). This effect was reversible, as FVIIa administration restored CFVs in all animals. Prothrombin times and activated partial thromboplastin times did not change significantly throughout the study. One single 10-minute infusion exerted complete antithrombotic effects for at least 6 hours, despite the fact that at this time point, plasma FVIIai levels were well below threshold concentrations. Epinephrine restored CFVs in 3 of 6 animals in which CFVs were inhibited by FVIIai. FVIIai exerts potent antithrombotic effects in this model; these effects were prolonged even after FVIIai was almost completely cleared from the circulation, probably as a result of the tight binding of FVIIai to TF. Thus, FVIIai might represent an antithrombotic substance of potential interest.

Oxygen radicals can induce preconditioning in rabbit hearts

Indirect evidence suggests that oxygen radicals may contribute to ischemic preconditioning. We directly investigated whether exposure to oxygen radicals per se, in the absence of ischemia, could reproduce the beneficial effects of ischemic preconditioning on infarct size and on postischemic contractile dysfunction. In one branch of the study, isolated rabbit hearts underwent 30 minutes of total global ischemia and 45 minutes of reperfusion (n=6, control group). A second group, before ischemia/reperfusion, was exposed for 5 minutes to a low flux of oxygen radicals generated by purine/xanthine oxidase (P/XO), followed by a 15-minute washout (n=6). Oxygen radical pretreatment significantly improved postischemic recovery of contractile function. We then investigated in another branch of the study whether this preconditioning effect would also reduce infarct size and whether it was mediated by protein kinase C activation. Control hearts were subjected to coronary artery occlusion for 30 minutes, followed by 2.5 hours of reperfusion (n=6). A second group, before coronary occlusion, was exposed to oxygen radicals and washout as described (n=8). A third group was subjected to oxygen radical infusion, but an inhibitor of protein kinase C (polymyxin B, 50 micromol/L) was administered throughout subsequent ischemia (n=7). A fourth group was exposed to oxygen radicals in the presence of scavengers (superoxide dismutase, 250 U/mL; catalase 500, U/mL; n=8). Pretreatment with oxygen radicals markedly reduced infarct size, from 65+/-19% of risk region in controls to 12+/-4% (P<.05). Protein kinase C inhibition significantly attenuated this effect (infarct size, 37+/-9% of risk region; P<.05 versus P/XO; P=NS versus controls). Oxygen radical-induced preconditioning was prevented by scavengers (infarct size, 55+/-14% of risk region; P<.05 versus P/XO; P=NS versus P/XO+polymyxin B). Our data show that in the absence of ischemia, exposure to low concentrations of oxygen radicals can reproduce the beneficial effects of ischemic preconditioning on infarct size and postischemic recovery of left ventricular function. Thus, oxygen radicals might be potential contributors to ischemic preconditioning.

Monoclonal antibody against tissue factor shortens tissue plasminogen activator lysis time and prevents reocclusion in a rabbit model of carotid artery thrombosis

BACKGROUND

Tissue factor (TF)-dependent activation of the coagulation is important in the pathophysiology of intravascular thrombus formation. We tested the effects of a monoclonal antibody against TF (AP-1) on lysis time induced by tissue-type plasminogen activator (TPA) and on reocclusion rate in a rabbit model of carotid artery thrombosis.

METHODS AND RESULTS

Intravascular thrombosis was obtained by placing an external constrictor around carotid arteries with endothelial injury. Carotid blood flow velocity ws measured continuously with a Doppler flow probe. Thirty minutes after thrombus formation, the rabbits received either AP-1 (0.15 mg/kg IV, n=8) or placebo (n=8). All rabbits also received TPA (80 microg/kg bolus plus 8 microg x kg(-1) x min(-1) infusion for up to 90 minutes or until reperfusion was achieved) and heparin (200 U/kg IV as a bolus). At reperfusion, TPA was discontinued, and the rabbits were followed for an additional 90 minutes. AP-1 shortened lysis time from 44+/-8 minutes (mean+/-SEM) in control rabbits to 26+/-7 minutes in AP-1 rabbits (P<.01). Reocclusion occurred in all control rabbits in 10+/-3 minutes, whereas it occurred in only two of eight AP-1 treated rabbits in 72 and 55 minutes (P<.01). No changes in prothrombin time and ex vivo platelet aggregation in response to various agonists were observed after AP-1 administration, indicating the absence of systemic effects by this antibody.

CONCLUSIONS

TF exposure and activation of the extrinsic coagulation pathway play an important role in prolonging lysis time and mediating reocclusion after thrombolysis in this model. AP-1, a monoclonal antibody against TF, might be suitable as adjunctive therapy to TPA.

Evaluation of electrofunctional data following argon-laser trabeculoplasty in primary open-angle glaucoma

To establish whether or not glaucomatous damage is reversible, we obtained pattern-reversal electroretinograms (PERGs) and visual evoked potentials (VEPs) in 25 eyes of 25 patients suffering from bilateral primary open-angle glaucoma (POAG) before and after argon-laser trabeculoplasty. The laser treatment was carried out in only one eye chosen at random, and the fellow eye was used as a control. In the present study we intended to verify the possibility of using electrofunctional techniques to determine the two distinct and, probably, consecutive glaucomatous alterations occurring in ganglion cells: functional (reversible) and anatomical (irreversible). The results obtained indicate that glaucomatous damage is irreversible. We propose that such alterations differ very slightly and that the current electrofunctional techniques may not be sufficiently sophisticated to distinguish between them.