Exploring novel genetic and hematological predictors of response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer

Introduction: The standard treatment for locally advanced rectal cancer (LARC) is neoadjuvant chemoradiotherapy (nCRT). To select patients who would benefit the most from nCRT, there is a need for predictive biomarkers. The aim of this study was to evaluate the role of clinical, pathological, radiological, inflammation-related genetic, and hematological parameters in the prediction of post-nCRT response. Materials and methods: In silico analysis of published transcriptomics datasets was conducted to identify candidate genes, whose expression will be measured using quantitative Real Time PCR (qRT-PCR) in pretreatment formaline-fixed paraffin-embedded (FFPE) samples. In this study, 75 patients with LARC were prospectively included between June 2020-January 2022. Patients were assessed for tumor response in week 8 post-nCRT with pelvic MRI scan and rigid proctoscopy. For patients with a clinical complete response (cCR) and initially distant located tumor no immediate surgery was suggested ("watch and wait" approach). The response after surgery was assessed using histopathological tumor regression grading (TRG) categories from postoperative specimens by Mandard. Responders (R) were defined as patients with cCR without operative treatment, and those with TRG 1 and TRG 2 postoperative categories. Non-responders (NR) were patients classified as TRG 3-5. Results: Responders group comprised 35 patients (46.6%) and NR group 53.4% of patients. Analysis of published transcriptomics data identified genes that could predict response to treatment and their significance was assessed in our cohort by qRT-PCR. When comparison was made in the subgroup of patients who were operated (TRG1 vs. TRG4), the expression of IDO1 was significantly deregulated (p < 0.05). Among hematological parameters between R and NR a significant difference in the response was detected for neutrophil-to-monocyte ratio (NMR), initial basophil, eosinophil and monocyte counts (p < 0.01). According to MRI findings, non-responders more often presented with extramural vascular invasion (p < 0.05). Conclusion: Based on logistic regression model, factors associated with favorable response to nCRT were tumor morphology and hematological parameters which can be easily and routinely derived from initial laboratory results (NMR, eosinophil, basophil and monocyte counts) in a minimally invasive manner. Using various metrics, an aggregated score of the initial eosinophil, basophil, and monocyte counts demonstrated the best predictive performance.

Additive negative prognostic value of coronary flow reserve in patients with left bundle branch block without inducible ischemia and without known coronary artery disease

Background

Left bundle branch block (LBBB) can be isolated thing, but it is also often associated with underlying coronary artery disease (CAD). Stress echocardiography (SECHO) is widely used as an imaging method for the diagnosis of CAD. However, the diagnostic value of stress echocardiography in patients (pts) with LBBB is limited.

Purpose

To evaluate negative prognostic value of coronary flow reserve (CFR) in pts with LBBB without inducible ischemia and without known CAD.

Methods

This retrospective study included 224 pts (98, 43.8% male gender, average age 66±11 years) with LBBB and without known CAD. All the pts had negative SECHO test according the Bruce protocol. Risk factors for CAD (diabetes, smoking, hypertension, high cholesterol and positive family history of CAD), Duke treadmill score, functional capacity (Metabolic Equivalents - METs) were recorded in all pts. Out of 224 pts, in 64 (29.5%) coronary flow reserve on the left anterior descending artery was assessed using pulsed Doppler echocardiography with adenosine in a dose of 140μcg/kg/body weight during 3 minutes. As the normal value we took value of CFR ≥2. Median follow up of the pts was 72 months (IQR 56.25–132 months) for the occurrence of MACE (cardiovascular death (CVD), non-fatal myocardial infarction (nfMI), coronary artery bypass graft (CABG) and percutaneous coronary revascularization (PCI).

Results

Out of 224 pts, 6 (2.7%) had positive SECHO test, 2 pts (0.9%) had died due to non-cardiac causes and 11 pts (4.9%) were lost to follow up so they were excluded from further analysis. The remaining 204 pts were divided in 2 groups: 1. pts with only negative SECHO (n=144, 68.8%); 2. pts with negative SECHO and normal CFR (n=64, 31.2%). During the follow-up period 22 out of 205 pts (10.7%) had an adverse event (6 CVD, 6 nfMI, 5 CABG, 8 PCI). Between the two groups there was no significant difference in risk factors and parameters of the SECHO test. Pts with CFR had significantly lower rate of MACE compared to the pts with only SECHO test (2, 3.1% vs 20, 14.2%, p=0.018, respectively). Using the Cox regression analysis, univariate predictors of MACE were insulin dependent diabetes (HR 10.851 [95% CI 2.095–56.220], p=0.004), Duke score (HR 0.603 [95% CI 0.414–0.878], p=0.008), and MET (HR 0.393 [95% CI 0.209–0.737], p=0.004). In the multivariate analysis only the insulin dependent diabetes remained an independent predictor of MACE (HR 6.906 [95% CI 1.100–43.363], p=0.039). Using the Kaplan-Meier survival curve we see that the pts with SECHO test and CFR had shorter event-free time compared to the pts with SECHO test (136.3±3.6 months vs 149.8±2.9 months, Log Rank 4.022, p=0.045) (Figure 1).

Conclusion

Normal value of CFR has good negative prognostic value in pts with LBBB without inducible ischemia and without known CAD, while pts with insulin dependent diabetes have more pronounced risk for the occurrence of adverse events.

Funding Acknowledgement

Type of funding sources: None.

Abstract 3463: Nischarin agonist rilmenidine inhibits pancreatic ductal adenocarcinoma cell migration and invasion

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive lethal malignancy due to the lack of early diagnosis and limited response to all treatment modalities. Early metastatic dissemination, rich desmoplastic stroma and immunosuppressive infiltrate are some of the features contributing to the poor prognosis of PDAC patients (5-year survival rate of less than 10%). Despite scientific progress in the development of new therapeutic regimes, PDAC patients in low- and middle-income countries have restricted access to high-cost innovative drugs. Recently, attention has been given to the concept of drug repurposing that could meet the need for novel but affordable and widely accessible therapies. Imidazoline receptor 1 Nischarin (NISCH, IR1, IRAS) is an integrin α5-interacting protein that acts as a tumor suppressor in breast cancer through modulation of cancer cell motility and survival. Importantly, NISCH has several clinically approved agonists that are used for the treatment of hypertension and are shown to modulate autophagy and reduce inflammation and fibrosis, which makes NISCH a potentially good therapeutic target for defying PDAC progression. Based on our GSEA analysis of NISCH expression in PDAC patient samples, NISCH was predicted to have an effect on cancer cell focal adhesion assembly and cytoskeletal organization. Therefore, we examined the effects of NISCH agonists on PDAC cells fitness in vitro. A panel of PDAC cell lines was tested in MTT assay to determine the effects of NISCH agonists rilmenidine, clonidine and moxonidine on cell viability. Flow cytometry, western blot and immunofluorescence were used to examine the effects of NISCH agonists on PDAC cell metabolism, migration and cytoskeletal organization. Tg(fli1:EGFP) zebrafish model was used to examine the effects of NISCH agonists on PDAC cell growth and invasion. We found that NISCH was expressed in PDAC cell lines, and that out of the three tested agonists, rilmenidine most potently inhibited cancer cell viability. Treatment with rilmenidine significantly reduced PANC-1, MIA PaCa-2 and BxPC-3 cell attachment to extracellular matrix (collagen type I and fibronectin) and migratory potential in wound healing and transwell assays. Furthermore, treatment with rilmenidine altered the organization of actin cytoskeleton and focal adhesion assembly, potentially through the reduction of intracellular reactive oxygen species (ROS) levels. Importantly, treatment with rilmenidine inhibited invasion of PANC-1 cells in Tg(fli1:EGFP) zebrafish model. With these antimigratory and potentially antimetastatic effects of rilmenidine, our study lays the ground for a more extensive examination of the biological role of NISCH in PDAC progression and implies that its agonists may be good candidates for drug repurposing in this type of cancer.

Citation Format: Marijana Pavlovic, Marija Ostojic, Kristina Zivic, Aleksandar Pavic, Tatjana Srdic-Rajic, Jelena Grahovac. Nischarin agonist rilmenidine inhibits pancreatic ductal adenocarcinoma cell migration and invasion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3463.

Abstract PO-040: Nischarin is expressed in pancreatic ductal adenocarcinoma and is a potential target for drug repurposing

The objective of this study was to examine the expression of Nischarin (NISCH) in pancreatic ductal adenocarcinoma (PDAC), and its potential as a target for drug repurposing. NISCH has been described as a tumor suppressor in breast and ovarian cancers, and there are several clinically approved agonists for this receptor. NISCH has also been reported as a scaffolding protein with a role in cell adhesion, invasion and metabolism – aspects of the PDAC biology that are of interest for therapeutical intervention. We examined mRNA and protein expression of NISCH in publicly available datasets, patient tumor samples, representative PDAC cell lines and patient-derived stellate cells. We found that NISCH is a prognostic marker in PDAC patients and that it is expressed in both cancer cells and cancer-associated stroma. Gene set enrichment analysis showed that NISCH expression was associated with the regulation of cell motility, cell cycle and energy metabolism. Indeed, NISCH knockdown in cancer cells induced reorganization of the actin cytoskeleton. Next, we tested the effects of three clinically approved NISCH agonists (rilmenidine, clonidine and moxonidine) on cancer cells and cancer-associated fibroblasts (CAFs). We found that rilmenidine, agonist with the highest affinity for the NISCH receptor, had the most potent effect. Rilmenidine impaired cancer cell adhesion, limited migration and decreased production of pro-metastatic cytokines and extracellular matrix deposition in cancer cell-CAF co-cultures. Our study lays a ground for more extensive examination of the role of NISCH in PDAC and implies that NISCH agonists may be good candidates for drug repurposing in this type of cancer.

Citation Format: Jelena Grahovac, Marijana Pavlovic, Marija Ostojic, Kristina Zivic, Daniel Galun, Tatjana Srdic-Rajic. Nischarin is expressed in pancreatic ductal adenocarcinoma and is a potential target for drug repurposing [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-040.

Hemodynamic heterogeneity of inadequate cardiac output increase identified by 2-dimensional volumetric exercise echocardiography: slow, stiff or weak heart?

Background

Two-dimensional (2-D) volumetric exercise stress echocardiography (ESE) provides an integrated view of preload reserve through end-diastolic volume (EDV) and left ventricular contractile reserve (LVCR) through end-systolic volume (ESV) changes.

Purpose

To assess the dependence of stroke volume (SV) and cardiac output (CO) upon LVCR EDV changes and heart rate (HR) during ESE.

Methods

We prospectively performed semi-supine bicycle or treadmill ESE in 1,344 patients (age 59.8±11.4 years; 550 female; ejection fraction = 62.5±8%) referred for known or suspected coronary artery disease in 20 quality controlled laboratories of 16 countries from 2016 to 2019. SV was calculated at rest and peak stress from raw measurement of LV EDV and ESV by biplane Simpson rule, 2-D echo. LVCR was the stress-rest ratio of force (systolic blood pressure by cuff sphygmomanometer/ESV, abnormal values &lt;2.0 identify a “weak” heart). Preload reserve was defined by an increase in LV EDV. Abnormal values (lack of EDV increase, peak EDV ≤ rest EDV) identify a “stiff” heart. Cardiac output was calculated as SV * HR (measured with standard EKG). HR reserve (stress/rest ratio) &lt;1.85 identifies a “slow” heart with chronotropic incompetence.

Results

By selection, all patients had negative SE by wall motion criteria. Of the 1,344 patients included in the study, 448 belonged to the lowest tertile of CO increase. Of them 326 (73%) achieved HR reserve &lt;1.85; 220 (49%) had a blunted LVCR and 374 (83%) a reduction of preload reserve, with 348 patients (78%) showing ≥2 abnormalities. The more the abnormal criteria, the worse the CO response, which was lowest in slow, stiff and weak hearts: see figure.

Conclusion

Patients with normal CO reserve during exercise usually have a fast, compliant and strong heart. Abnormal CO reserve is associated with heterogeneous hemodynamic responses, with slow, stiff and/or weak hearts. The clarification of underlying hemodynamic heterogeneity is the prerequisite for a personalized treatment, and can be easily extracted from a standard 2-D volumetric SE. Hearts with normal CO are all alike; every heart with abnormal CO is abnormal in its own way.

CO % changes in subsets (*p&lt;0.001)

Funding Acknowledgement

Type of funding source: None

Time-dependent improvement in coronary flow reserve in collateral donor artery following successful recanalization of the Coronary Chronic Total Occlusion

Background

Coronary chronic total occlusion (CTO) is characterized by the presence of collateral blood vessels which can provide additional blood supply to CTO-artery dependent myocardium. Successful CTO recanalization is followed by significant decrease in collateral donor artery blood flow and collateral derecruitment.

Purpose

Study aim was to assess time-dependent changes in coronary flow reserve (CFR) in collateral donor artery after CTO recanalization and identify factors that influence these changes.

Methods

Our study enrolled 31 patients with CTO scheduled for percutaneous coronary intervention (PCI). Non-invasive CFR was measured before PCI in collateral donor artery, and 24h and 6 months post-PCI in CTO and collateral donor artery. Gated SPECT MIBI was performed before PCI, while quality of life was assessed by Seattle angina questionnaire (SAQ) pre-PCI, and 6 months after PCI.

Results

Collateral donor artery showed significant increase in CFR 24h after CTO recanalization compared to pre-PCI values (2.30±0.49 vs. 2.71±0.45, p=0.005), which remained unchanged after 6 months (2.68±0.24). Maximum baseline blood flow velocity of the collateral donor artery showed significant decrease measured 24h post-PCI compared to pre-PCI values (0.28±0.06 vs. 0.24±0.04m/s), and remained similar after 6-months. There was no significant difference in maximum hyperemic blood flow velocity pre-PCI, 24h and 6 months post-PCI. CFR change of the collateral donor artery 24h post-PCI compared to pre-PCI values showed inverse correlation with left ventricle ejection fraction (LVEF) measured on SPECT. CFR changes showed no correlation with the changes in quality of life assessed by SAQ post-PCI compared to pre-PCI.

Conclusions

Significant increase in CFR of the collateral donor artery was observed within 24h after successful recanalization of CTO artery, which maintained constant after the 6 months follow-up. This increase was largely driven by the significant reduction in the maximum baseline blood flow velocity within 24h after CTO recanalization compared to pre-PCI values. Our results suggest that possible benefit of CTO recanalization could be the improvement in physiology of the collateral donor artery.

Funding Acknowledgement

Type of funding source: None

Prediction of medium term mortality in diabetics with complex ischemic heart disease after first isolated coronary artery bypass grafting: comparison of FREEDOM, SYNTAX II and our formula

Background

Controversies exist how to predict medium term mortality (Mt) in diabetics (DM) with 3 vessel (3VD) and/or left main (LM) disease undergoing myocardial revascularization ranging from Syntax Score II (SSII) where DM was not predicative variable up to FREEDOM formula which was derived, just from population with DM (without LM), having DM patients (Pts) requirement of insulin as one of predicative variable.

Purpose

To compare predicative power of SSII, FREEDOM and formula developed in our institution in Pts post first isolated CABG with 3VD and/or LM with DM.

Methods

From our prospective data base of 2455 consecutive pts who had the first isolated CABG in the period 01/2012–12/2014 with complex Ischemic Heart Disease with 100% follow up of 4 years all-cause Mt we created by random sampling Training (1321; Mt:10.4%; DM 511; Mt:13.3%) and Validation (1134; Mt:10.0%; DM 414; Mt: 11.8%) sets. After deriving predicative formula (Cox regression) from training population we validated FREEDOM, SSII and Our Formula in 414 pts with DM from the Validation set.

Results

Characteristics of pts, our formula, predicating power by C Statistics, Calibration plots and Brier scores are presented in Picture 1.

Conclusions

FREEDOM formula designed just for DM pts with complex Ischemic Heart Disease without LM had the smallest standard error in the estimate, but moderate C statistics as Syntax Score II and our formula which may be used for pts with and without DM and 3VD and/or LM.

Picture 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Ministry of education, science and technology development, Republic of Serbia

P4985Blunted heart rate reserve as an imaging-independent predictor of abnormal left ventricular contractile reserve

Background

Stress echocardiography (SE) relies on regional wall motion and left ventricular contractile reserve (LVCR) based on force (systolic blood pressure/end-systolic volume). An additional non-imaging parameter based on EKG is the blunted heart rate reserve (HRR) which is a simple marker of altered autonomic balance and is associated with worse prognosis independently of ischemia.

Aim

To assess the relationship between HRR and LVCR in patients undergoing SE.

Methods

We enrolled 4707 patients (age 63.6±11.3 yrs, 2800 males) referred to SE for known or suspected coronary artery disease (CAD) and/or heart failure (HF) in 21 SE laboratories in 8 countries. The employed stress was exercise (n=2062), dipyridamole (n=2007) or dobutamine (n=638). We assessed LVCR (stress/rest ratio of force=systolic blood pressure/end-systolic volume, ESV). Stress-specific abnormal cutoff value of LVCR were <2.0 for exercise and dobutamine and <1.1 for dipyridamole. All readers had passed the upstream quality control reading for wall motion abnormalities and ESV. HR (with 12-lead ECG) was obtained each minute and recorded at rest and peak stress. HR reserve (HRR) was calculated as the peak/rest HR ratio.

Results

HRR was related to LVCR at cumulative (n=4707; r=0.351; p<0.001: see figure) and stress-specific analysis for exercise (r=0.351; p<0.001), dipyridamole (r=0.241; p<0.001) and dobutamine (r=0.214; p<0.001). At multivariate logistic regression analysis, blunted HRR (optimal cutoff: 1.73 for exercise, 1.306 for dipyridamole, 1.932 for dobutamine) was a significant predictor of abnormal LVCR at stress-specific analysis for exercise (Odds ratio = 0.285, 95% Confidence Intervals: 0.149–0.546, p=0.0001), dobutamine (Odds ratio = 0.187, 95% Confidence Intervals: 0.057–0.617, p=0.0001) and dipyridamole (Odds ratio = 0.263, 95% Confidence Intervals: 0.115–0.602, p=0.002).

Conclusion

A blunted HRR is a useful non-imaging predictor of abnormal LVCR response during exercise or pharmacological SE. HRR is a simple biomarker of autonomic unbalance of physiologic and potentially prognostic meaning. A “slow heart” during stress (with blunted HRR) is more often a “weak heart”, with blunted increase in force.

P4587Impact of diabetes mellitus on myocardial revascularisation method in the light of the 2018 ESC/EACTS guidelines: Results from the PROUST Study

Background/Introduction

Results of currently available randomized trials have shown divergent outcomes in diabetic patients undergoing percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). The 2018 ESC/EACTS guidelines on myocardial revascularization do not recommend PCI in patients with diabetes and SYNTAX score ≥23.

Purpose

We aimed to compare the all-cause 4-year mortality after revascularization for complex coronary artery disease (CAD) in diabetics.

Methods

The study group comprised consecutive diabetics with angiographically proven three-vessel CAD (≥50% diameter stenosis) and/or unprotected left main CAD (≥50% diameter stenosis) without major hemodynamic instability, who were treated in two institutions with PCI or referred for CABG between 2008 and 2010. All-cause mortality was ascertained by telephone contacts and/or from Mortality Registries.

Results

Using the hospital data system, 5145 patients were screened and 4803 elected not to follow the inclusion criteria. Out of 342 included patients, 177 patients underwent PCI and 165 patients were referred for CABG. Patients with whom CABG was performed were significantly older (64.69±8.8 vs. 62.6±9.4, p=0.03), more often on insulin treatment (91/165=55.2% vs. 26/177=14.7%, p<0.01), had more complex anatomical characteristics i.e. higher SYNTAX scores (32.5 IQR (15) vs. 18.0 IQR (15), p<0.01) and with left main stenosis (70/165=42.4% vs. 7/177=4.0%, p<0.01), compared to patients treated with PCI. The cumulative incidence rates of all-cause death were significantly different between PCI and CABG at 4 years (16/177=9.0% vs. 26/165=15.7%, respectively, log-rank p=0.03). There was a higher incidence of all-cause mortality in PCI patients with intermediate (23–32) and high (≥33) SYNTAX scores compared with those with low (0–22) SYNTAX scores (6/32=18.8% vs. 6/124=4.8%, log-rank p=0.01; 4/21=19.1% vs. 6/124=4.8%, log-rank p=0.02, respectively). On the contrary, patients who underwent CABG displayed similar morality rates irrespective of the SYNTAX scores (SYNTAX 0–22: 5/34=14.7%; SYNTAX 23–32: 9/54=16.7%; SYNTAX ≥33: 12/77=15.6%; log-rank p=0.9). Finally, when compared with CABG, more deaths were observed following PCI with intermediate and high SYNTAX scores (intermediate SYNTAX (23–32) PCI: 6/32=18.8% vs. CABG: 26/165=15.8%, log-rank p=0.94; high SYNTAX (≥33) PCI: 4/21=19.1% vs. CABG 26/165=15.8%, log-rank p=0.87).

Conclusions

During a 4-year follow-up, CABG in comparison with PCI was associated with a higher rate of all-cause death, which can be accounted for by older age and comorbidities. In diabetics, our analysis is suggestive that PCI probably should be avoided in patients with SYNTAX ≥23, which is in concordance with the most recent guidelines. Individualized risk assessment as well as quantification of CAD by SYNTAX score remains essential in choosing appropriate revascularization method in patients with diabetes and complex CAD.

Acknowledgement/Funding

None

P2521Exercise-Based Cardiac Rehabilitation in post myocardial infarction patients with mid-range ejection fraction

Patients and methods

Out of 2753 patients who were admitted to our three weeks in- hospital secondary prevention program – exercised based cardiac rehabilitation, we analyze a total of 219 patients who were admitted early after coronary revascularization (percutaneus coronary interventions or coronary bypass surgery) with HFmrEF. The majority of patients were males (68%). Risk factors and co morbidities were noted. Patients were selected for exercise training after six minute walking test or exercise stress test (cardiopulmonary dominantly to evaluate unexpected exertional dyspnea). After 3 weeks in house cardiac rehabilitation the patients were re-tested.

Results

The major comorbidities in our patient population were as follows: hypertension, diabetes and dyslipidemia. Six minutes walking test was performed and the total distance walked ranged from 120 to 480 meters and the beginning of the program. Patient had 7 -days a week training program. After the 3 weeks in hospital exercise rehabilitation the improvement in the test was ∼32%. Cardiopulmonary test showed also improvement of functional capacity.We noted several rhythm disturbance complications by telemetry (VES, SVES). None had acutisation of heart failure (with peripheral edema and congestion). All patients fulfilled cardiac rehabilitation program.

Conclusions

Supervised multidisciplinary cardiac rehabilitation program, including an individualized exercise component is effective and can improve functional status and exercise tolerance in patient with HFmrEF after myocardial infarction.

Clopidogrel cessation triggers aspirin rebound in patients with coronary stent

WHAT IS KNOWN AND OBJECTIVE

Premature discontinuation of clopidogrel in patients undergoing percutaneous coronary intervention is a significant risk factor for thrombotic adverse outcomes. However, recent studies indicate that even discontinuation of long-term use of clopidogrel may be associated with multiple adverse outcomes, that is, rebound phenomenon whose mechanism is not definitely clear. The aim of the study was to examine the effect of clopidogrel withdrawal in those on combined aspirin and clopidogrel therapy.

METHODS

This prospective, multicenter study enrolled 200 patients who underwent coronary stent implantation and were on dual antiplatelet therapy (100 mg aspirin + 75 mg clopidogrel) 1 year after the stent placement. In all patients, we measured the platelet aggregation, by multiplate electrode aggregometry, using two agonists [adenosine diphosphate with PGE1 (ADPHS) and arachidonic acid (ASPI)] two times: on the day of cessation of clopidogrel and 90 days after clopidogrel was stopped.

RESULTS AND DISCUSSION

Following clopidogrel discontinuation, we registered an increase in ASPI values (P < 0·001), linear correlation between changes in ASPI and ADPHS values (P = 0·009) and significant difference in the values of ASPI first quartile of ADPHS compared with the other three (P < 0·001, P = 0·016, P < 0·001, I vs. II, I vs. III and I vs. IV quartile of ADPHS, respectively).

WHAT IS NEW AND CONCLUSION

Our findings show that cessation of clopidogrel causes loss of antiplatelet synergism with aspirin, leading to a weakening of the response to aspirin, which may be one explanation for the rebound after the clopidogrel cessation.

Eye lens dosimetry in interventional cardiology: results of staff dose measurements and link to patient dose levels

Workers involved in interventional cardiology procedures receive high eye lens dose if protection is not used. Currently, there is no suitable method for routine use for the measurement of eye dose. Since most angiography machines are equipped with suitable patient dosemeters, deriving factors linking staff eye doses to the patient doses can be helpful. In this study the patient kerma-area product, cumulative dose at an interventional reference point and eye dose in terms of Hp(3) of the cardiologists, nurses and radiographers for interventional cardiology procedures have been measured. Correlations between the patient dose and the staff eye dose were obtained. The mean eye dose was 121 µSv for the first operator, 33 µSv for the second operator/nurse and 12 µSv for radiographer. Normalised eye lens doses per unit kerma-area product were 0.94 µSv Gy⁻¹ cm⁻² for the first operator, 0.33 µSv Gy⁻¹ cm⁻² for the second operator/nurse and 0.16 µSv Gy⁻¹ cm⁻² for radiographers. Statistical analysis indicated that there is a weak but significant (p < 0.01) correlation between the eye dose and the kerma-area product for all three staff categories. These values are based on a local practice and may provide useful reference for other studies for validation and for wider utilisation in assessing the eye dose using patient dose values.

Echocardiography in sports cardiology: LV remodeling in athletes' heart — Questions to be answered

An enhanced risk of undesirable events has been described in individuals who take part in mainly high intensity physical activities. Underlying cardiac disorders are the most common cause of sudden death during sports activities. Left ventricular remodeling is associated with a long-term athletic training. Echocardiography is an easy, non-invasive and efficient way to the precise distinction between these exercise-induced changes, called “physiological” hypertrophy, that revert after detraining, and those of cardiac disorders or “pathological” hypertrophy. The identification of a cardiac disease in an athlete usually leads to his disqualification in an attempt to reduce the risk. On the other hand, a false diagnosis of a cardiac disease in an athlete may also lead to disqualification, thus depriving him of the various benefits from sports participation. Pronounced left ventricular dilatation and hypertrophy should always be suspected for underlying cardiac disease. Physiological left ventricular remodeling is associated with normal systolic and diastolic left ventricle function. Both global and regional left ventricle diastolic function should be evaluated. New echocardiographic techniques (tissue Doppler imaging, strain rate) have revealed “super — diastolic” left ventricle function in athletes, adding the new quality in differential diagnosis od athlete's heart syndrome.

Nobori™ drug eluting stent system: clinical evidence update

Drug eluting stents (DES) have changed the landscape of interventional cardiology with their high efficacy in preventing restenosis. Several DES are available for clinical use with different drugs, polymers and platforms. The Nobori™ is a novel generation drug eluting stent. The drug, Biolimus A9™, a sirolimus analogue, is immersed in a biodegradable polymer which is applied solely to the abluminal surface of a flexible stainless steel stent platform. The drug-polymer matrix is designed to release the drug simultaneously with the polymer degradation in a process lasting between 6-9 months. The coating design along with the lipophilicity of the drug is expected to optimize drug distribution and to reduce its release into the peripheral circulation. The drug free luminal surface might reduce negative impact on endothelization observed with DES with circumferential coating and durable polymers. Nobori™ stent is extensively studied in the comprehensive NOBORI clinical program. This stent showed superiority versus Taxus Liberte stent for in-stent late loss at 9 months in NOBORI 1 study, similarity to Cypher stent in NOBORI CORE study and superior performance versus both Taxus and Cypher stent in the study indirectly assessing endothelial function at 6-9 months after stent implantation. The landmark of NOBORI trials is very low rate of late and very late stent thrombosis along with exceptionally low target lesion revascularization rate.

Initial clinical experience with PerDUCER device: promising new tool in the diagnosis and treatment of pericardial disease

BACKGROUND

The idea to enter the normal pericardial sac safely was unrealistic until recently. The development of a novel instrument (PerDUCER pericardial access device) for percutaneous access to the pericardium could potentially have a significant impact, not only on patients with pericardial diseases but even more, or primarily, on diagnosis and treatment of myocardial and coronary disease and arrhythmias.

HYPOTHESIS

The overall objective of the present study was to evaluate the feasibility and safety of the percutaneous pericardial access with PerDUCER in patients with pericardial disease, and to analyze our initial experience with this new technique, with particular emphasis on sequential procedural steps.

METHODS

The device was studied in five patients with pericardial disease (two men, mean age 50.4 years, range 30-68, four with normal body mass index). The procedure consists of two distinct techniques: (1) access to the mediastinal space, and (2) pericardial capture, puncture, and insertion of the guidewire. Access to the mediastinal space includes the introduction of a blunt cannula, a 0.038 guidewire, a dilator-introducer sheath set, and insertion of the PerDUCER device. Key points of the PerDUCER procedure are as follows: introduction of the blunt cannula without resistance, placement of the dilator-introducer sheath at the upper third of the heart, systolic movements of the PerDUCER device, successful vacuum and capture of pericardium, puncture and introduction of the intrapericardial guidewire.

RESULTS

Access to the mediastinal space was accomplished in four of five patients, as were pericardial capture and probably puncture. However, despite numerous successful captures and probably punctures of pericardium, we were not able to confirm introduction of the intrapericardial guidewire into the pericardial cavity in any of our patients (0/5). The procedure was very well tolerated in all patients (5/5). No major complications developed during the procedure, bearing in mind that the intrapericardial placement of the guidewire was not achieved. Minor complications included pain at the dilator-introducer sheath entry site (5/5) and mild transient fever (2/5).

CONCLUSIONS

According to the present experience, we believe that, with minor modifications, the PerDUCER device could be successfully implemented for pericardial entry in patients with pericardial disease. Further studies are needed to evaluate the feasibility and safety of this new instrument in patients with a normal pericardium. This could open a most exciting spectrum of possible implementations of the device in the future.

Preliminary characterization of lactic acid bacteria isolated from Zlatar cheese

AIMS

Isolation, characterization and identification of lactic acid bacteria (LAB) from artisanal Zlatar cheese during the ripening process and selection of strains with good technological characteristics.

METHODS AND RESULTS

Characterization of LAB was performed based on morphological, physiological and biochemical assays, as well as, by determining proteolytic activity and plasmid profile. rep-polymerase chain reaction (PCR) analysis and 16S rDNA sequencing were used for the identification of LAB. PCR analysis was performed with specific primers for detection of the gene encoding nisin production. Strains Lactobacillus paracasei subsp. paracasei, Lactobacillus plantarum, Lactobacillus brevis, Lactococcus lactis subsp. lactis, Enterococcus faecium and Enterococcus faecalis were the main groups present in the Zlatar cheese during ripening.

CONCLUSIONS

Temporal changes in the species were observed during the Zlatar cheese ripening. Mesophilic lactobacilli are predominant microflora in Zlatar cheese.

SIGNIFICANCE AND IMPACT OF THE STUDY

In this study we determined that Zlatar cheese up to 30 days old could be used as a source of strains for the preparation of potential starter cultures in the process of industrial cheese production. As the Serbian food market is adjusting to European Union regulations, the standardization of Zlatar cheese production by using starter culture(s) based on autochtonous well-characterized LAB will enable the industrial production of this popular cheese in the future.

Prognostic value of myocardial viability determined by a 201Tl SPECT study in patients with previous myocardial infarction and mild-to-moderate myocardial dysfunction

The prognostic meaning of myocardial viability is most important in patients with severe left ventricular dysfunction and ischaemic heart disease, but its prognostic significance in patients with previous myocardial infarction and mild-to-moderate myocardial dysfunction is uncertain. The aim of this study was to assess the prognostic value of a 201Tl single photon emission computed tomography (SPECT) rest-redistribution study in patients with previous myocardial infarction, ischaemic heart disease and mild-to-moderate myocardial dysfunction. Myocardial viability was assessed in 55 patients (50 male; mean age 58+/-9 years) by 201Tl SPECT rest-redistribution (after 4 h) scintigraphy. All patients had previous myocardial infarction (>3 months) and angiographically documented coronary artery disease, with the mean ejection fraction of 43+/-10%. Out of 55 patients, 20 were medically treated and 35 were revascularized. The follow-up period for adverse cardiac events, including death and non-fatal myocardial infarction, was 12 months. 201Tl SPECT study was positive for myocardial viability in 36 patients (65%) and negative in 19 patients (35%). Sensitivity, specificity, positive and negative predictive values for functional improvement in the follow-up period were 85%, 75%, 92% and 60%. Out of seven (13%) cardiac events in the follow-up period (four cardiac deaths and three reinfarctions), five occurred in 20 medically treated patients and two in 35 revascularized patients (25% vs 6%, P <0.05). Absence of myocardial viability was the only variable associated with adverse cardiac events (P =0.02). Survival at 12 months, as determined by using Kaplan-Meier analysis, was 56% for medically treated and non-viable patients, 80% for revascularized and non-viable patients, 91% for medically treated and viable patients, and 100% for revascularized and viable patients (P =0.0034). These findings suggest that in patients with previous myocardial infarction and mild-to-moderate myocardial dysfunction, the absence of myocardial viability as determined by the 201Tl SPECT study was the only variable associated with adverse cardiac events. The best 12 month survival was observed in revascularized viable patients, whereas the worse prognosis was found in non-viable, medically treated patients.