Percutaneous coronary intervention with everolimus-eluting stents versus coronary artery bypass surgery in patients with stable angina and an isolated proximal left anterior descending artery disease

Background/Introduction

Revascularization of the proximal segment of left anterior descending artery (pLAD) demonstrates an additional prognostic significance in survival for patients with multivessel disease. It is also indicated for symptomatic relief in patients with stable angina who are receiving optimal medical treatment in the presence of limiting angina or angina equivalent. Both coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) are still commonly needed as therapeutic options for pLAD disease.

Moreover, Everolimus-eluting stents (EES) have demonstrated superiority in safety and efficacy among other types of second or new generation drug-eluting stents.

Purpose

We aim to evaluate the long-term outcomes of PCI with EES compared to CABG surgery with left internal mammary artery, in patients with stable angina and an isolated single vessel pLAD disease.

Methods

The sample consisted of 824 patients with isolated pLAD and chronic stable angina; 445 participants were included in the EES-PCI group, and 379 were included in the CABG group. The study's primary endpoint was the occurrence of major adverse cardiac events (MACEs), namely, cardiac death, myocardial infarction (MI) not attributed to a non-target vessel and target lesion revascularization as a composite index. Secondary endpoints were Patient-Related Outcome (PRO; a composite index of all-cause mortality, any MI related to any coronary artery, any revascularization conducted to any coronary artery), individual components of MACEs, recurrence of stable or unstable angina or a nonfatal arrhythmia and disease progression of other lesions. For the comparisons between the two groups, chi-square tests and Fisher's exact tests, were used, as appropriate.

Results

During the 4.6 years of follow-up period, no statistically significant difference was observed between the two study groups in respect to the primary endpoint MACE (8.1% versus 7.4%, p=0.71). Concerning secondary endpoints, repeat revascularization (3.6% versus 2.9%, p=0.58), cardiac death (2.9% versus 3.2%, p=0.84), MI (1.6% versus 1.3%, p=0.76) and PRO (16.9% versus 17.7%, p=0.76) did not significantly differ between the two groups. Recurrence of angina was more frequent in the EES-PCI group (14.9% versus 8.4%, p=0.005) even though higher Class of angina was found less common in EES patients than in CABG patients (p<0.001). Patients treated with EES-PCI had lower rates of onset of arrhythmias compared to those treated with CABG (6.3% versus 11.9%, p=0.005). Finally, revascularization in other than target lesion was more frequent in the stent than in the surgery arm (6.3% versus 3.2%, p=0.04); as a consequence, higher rates of revascularization in any vessel was recorded in the PCI group than the CABG one (9.9% versus 5.8%, p=0.03).

Conclusion

PCI with EES seem to have similar long-term clinical outcomes compared with CABG in patients with isolated pLAD disease.

Funding Acknowledgement

Type of funding source: None

P2802Second-generation drug-eluting stents versus coronary artery bypass surgery in patients with stable angina and an isolated lesion in the proximal left anterior descending artery

Background/Introduction

Both coronary artery bypass grafting surgery (CABG) and percutaneous coronary intervention (PCI), especially with the use of new-generation drug-eluting stents (DES), remain the most common therapeutic options of coronary artery disease, especially when the proximal segment of left anterior descending artery (pLAD) is involved. There are only a small number of studies comparing these approaches in patients with isolated lesions in LAD.

Purpose

We aim to compare the long-term outcomes of PCI with second-generation DES versus CABG surgery with left internal mammary artery, in patients with stable angina and an isolated single vessel pLAD disease.

Methods

The study population consisted of 1010 consecutive patients with stable angina and an isolated pLAD that were treated either with PCI with second generation (zotarolimus or everolimus) DES (631 patients) or with CABG surgery (379 patients). The primary endpoint was the occurrence of any major adverse cardiac event (MACE) namely cardiac death, non-fatal myocardial infarction and target lesion revascularization (using either percutaneous or surgical technique) as a composite index. Other evaluated main clinical outcomes were the components of MACE, patient-related outcome (PRO-a composite index of all-cause mortality, any myocardial infarction, any revascularization), recurrence of stable angina and arrhythmias occurrence.

Results

Lower rates of in-hospital complications (0.3% versus 12.1%, p<0.001) and shorter hospitalization [median, 1 (interquartile-range: 1–4) versus 8 (interquartile-range: 7–11), p<0.001] were recorded in the PCI group compared with the surgery arm. During the follow-up period (mean, 4.6±2.5 years), no statistical difference was observed in respect to MACE between the two study groups (10.1% versus 7.4%, p=0.14). Higher rates of repeat revascularization were detected in patients treated with PCI than those treated with CABG (5.5% versus 2.9%, p=0.05). Concerning other secondary endpoints, cardiac death (2.9% versus 3.2%, p=0.78), myocardial infarction (1.7% versus 1.3%, p=0.60), and PRO (18.9% versus 17.7%, p=0.64) did not differ in a statistically significant manner between the two techniques. Recurrence of stable angina was significantly increased in PCI (15.6% versus 8.4%, p=0.001), whereas arrhythmias occurrence was most common in the surgery group (6.3% versus 11.9%, p=0.002).

Conclusion

PCI with second-generation DES seem to have similar long-term clinical outcomes compared with CABG in patients with isolated LAD disease, highlighting the excellent long-term outcomes of both therapeutic approaches

Estimating the treatment cascade of chronic hepatitis B and C in Greece using a telephone survey

Accurate diagnosis and treatment rates for chronic hepatitis B (HBV) and C virus (HCV) infections are usually missing. Aim of this study was to estimate the HBV and HCV treatment cascade (proportion and absolute numbers of tested, aware/unaware, infected and treated) in Greek adults. A telephone survey was conducted in a sample representative of the Greek adult general population. Prevalence rates were age-standardized for the Greek adult population and corrected for high-risk individuals not included in the survey. Of the 9974 participants, 5255 (52.7%) had been tested for HBV and 2062 (20.7%) for HCV with the proportion varying according to age and being higher in middle-age groups (P < 0.001). HBsAg was reported positive in 111/5255 (2.11%) and anti-HCV in 26/2062 (1.26%) tested cases. The age-adjusted prevalence was estimated to be 2.39% for HBV and 1.79% for HCV. Taking into account individuals at high risk for viral hepatitis not included in the survey, the 'true' prevalence was estimated to be 2.58% for HBV and 1.87% for HCV. Anti-HBV and anti-HCV treatment had been taken by 36/111 (32.4%) chronic HBV and 15/26 (57.7%) chronic HCV patients. In conclusion, almost 50% of chronic HBV and 80% of chronic HCV patients in Greece may be unaware of their infection, while only 32% or 58% of diagnosed chronic HBV or HCV patients, respectively, have been ever treated. Therefore, intensive efforts are required to improve the efficacy of screening for HBV and particularly for HCV as well as to reduce the barriers to treatment among diagnosed patients.

Evidence for lack of cross-genotype protection of CD4+ T cell responses during chronic hepatitis C virus infection

CD4+ T lymphocyte responses are thought to play a major role in control of the hepatitis C virus (HCV). Few, however, have been mapped down to the level of peptide and HLA restriction. Furthermore, the ability of such T cells to respond to viruses which differ in genotype has not been addressed in detail. In most cases of persistent infection with HCV, CD4 proliferative responses are weak or absent. From a large cohort of persistently infected patients, we identified an individual with unusually robust and persistent responses in the face of chronic infection. We firstly mapped two peptide epitopes to regions of the nonstructural protein NS4 (aa1686-1705 and aa 1746-1765). However, in contrast to the genotype 1a derived antigens used for mapping, the infecting virus was identified as genotype 3a. Strikingly, the patient's CD4 response to these epitopes were specific only for the genotype 1a sequence, and did not recognize genotype 3a synthetic peptides. Serologic assays indicated that prior exposure to HCV of genotype 1 had occurred. This patient therefore maintains strong CD4 proliferative responses which are genotype specific and not cross-reactive. The apparent 'misdirection' of these nonprotective responses has important implications for the role of natural and vaccine induced CD4 responses in the face of variable viruses.

The ica operon and biofilm production in coagulase-negative Staphylococci associated with carriage and disease in a neonatal intensive care unit

Coagulase-negative staphylococci (CoNS) are a major cause of sepsis in the neonatal intensive care unit (NICU). We evaluated the hypothesis that the ica operon and biofilm production are associated with CoNS disease in this setting. CoNS associated with bacteremia or blood culture contamination and from the skin of infants with CoNS bacteremia or healthy controls were obtained during a prospective case-control study on a busy NICU. A total of 180 strains were identified, of which 122 (68%) were Staphylococcus epidermidis and the remainder were S. capitis (n = 29), S. haemolyticus (n = 11), S. hominis (n = 9), S. warneri (n = 8), and S. auricularis (n = 1). The presence of the genes icaA, icaB, icaC, and icaD was determined by PCR, and biofilm production was examined using qualitative (Congo red agar [CRA]) and quantitative (microtiter plate) techniques. There were no significant differences in the presence of the ica operon or CRA positivity among the four groups of strains. However, quantitative biofilm production was significantly greater in strains isolated from either the blood or the skin of neonates with S. epidermidis bacteremia. We conclude that the quantity of biofilm produced may be associated with the ability to cause CoNS infection. This conclusion suggests that the regulation of biofilm expression may play a central role in the disease process.

Ex vivo analysis of phenotype and TCR usage in relation to CD45 isoform expression on cytomegalovirus-specific CD8+ T lymphocytes

Human cytomegalovirus (CMV) is a ubiquitous pathogen which sets up a lifelong persistent infection and which can lead to significant disease in the immunosuppressed. The immunological mechanisms controlling CMV in the long term are not defined completely, but CD8+ T lymphocytes are thought to play an important role. Antiviral CD8+ T lymphocytes may exist in very large pools in healthy individuals. Although the detailed composition of these pools is not completely understood, there is known to be heterogeneity, in particular of CD45 isoform expression. We have therefore investigated the CD8+ T-lymphocyte response against CMV directly ex vivo using Class I tetramers combined with stains for a range of phenotypic markers followed by four-colour flow cytometric analysis. In particular, we examined expression of these phenotypic markers in relation to the expression of CD45 isoforms. We found that a spectrum of phenotypes exists stably, from CD45R0(high)/RA(low) through CD45RA(high)/R0(low), and that expression of other surface markers such as CD28 and CD62L, and also TCR usage, may vary in parallel with CD45 isoform expression. In some individuals, expansions of antigen-specific CD8+ T lymphocytes bearing specific TCR Vbeta chains were restricted to cells of particular CD45 isoforms. Immunity against CMV comprises a large population of CD8+ T lymphocytes with heterogeneous potential, a spectrum in which CD45 isoform expression may play a central role.

Direct ex vivo measurement of CD8(+) T-lymphocyte responses to human parvovirus B19

Parvovirus B19 is a common human pathogen which can cause severe syndromes, including aplastic anemia and fetal hydrops. The mapping of the first parvovirus B19-derived CD8(+) T-lymphocyte epitope is described. This HLA-B35-restricted peptide derives from the nonstructural (NS1) protein and is strongly immunogenic in B19 virus-seropositive donors.

Studies of human antiviral CD8+ lymphocytes using class I peptide tetramers

Understanding the interactions between a host and a pathogen relies crucially on quantitative measurements of immune responses. Until recently, measurements of the levels of cellular immune responses, i.e. those mediated by CD4+ and CD8+ T lymphocytes have depended largely on culture in vitro and subsequent measurement of specific functions (such as cytolysis). More recently, new technologies based around tetrameric class I peptide complexes (tetramers) have allowed immunologists to measure CD8+ T lymphocyte levels directly ex vivo and independently of function. Since CD8+ lymphocytes play a key role in a number of important human viral infections, these tools have yielded useful insights into the dynamics, phenotype and function of human antiviral lymphocyte populations. In this review we describe some of the basic aspects of the biology of virus-specific CD8+ lymphocytes, and the current methods available to detect them. The use of tetramers has, in just four years, transformed our understanding of the immune responses against HIV, HTLV-1, HBV, HCV, CMV and EBV, and holds promise in a number of areas where quantitative analysis of the antiviral response in terms of both number and function is critical.

A multi-centre study of nosocomial methicillin-resistant Staphylococcus aureus in Greece. Greek MRSA Study Group

All 105 non-replicate consecutive Staphylococcus aureus strains isolated in 1997 from seven Greek hospitals, were found to be susceptible to vancomycin, teicoplanin and chloramphenicol, but only five (8%) were susceptible to all 16 antibiotics tested. Forty-three (41%) isolates were methicillin-resistant, 58% homogeneously (homMRSA) and 42% heterogeneously (hetMRSA). Resistance of homMRSA strains to other antibiotics was generally high (88-100%), although only one strain was resistant to netilmicin. Resistance in hetMRSA (6-39%) or in MSSA (5-11%) was significantly lower. Consequently, the majority (76%) of homMRSA were multi-drug resistant, while the dominant phenotype of hetMRSA and MSSA was resistance to penicillin (50% and 76%, respectively). Comparison of these strains with isolates from 1994 showed higher resistance rates to erythromycin among MSSA, to erythromycin and amikacin among hetMRSA and to rifampicin among homMRSA strains.

Reduced susceptibility to vancomycin of nosocomial isolates of methicillin-resistant Staphylococcus aureus

The MICs of vancomycin for 56 random nosocomial Staphylococcus aureus isolates homogeneously resistant to methicillin (homMRSA), 16 heterogeneously resistant isolates (hetMRSA) and 25 susceptible isolates (MSSA) were determined by a standard broth microdilution method. Representative isolates were also tested by an agar incorporation method, the Etest and population analysis. Although always in the susceptible range, MICs of vancomycin for homMRSA were significantly higher than those for hetMRSA or MSSA. Moreover, a homMRSA strain belonging to one of the major Greek MRSA clones contained a sub-population of cells that could grow in the presence of vancomycin 8 mg/L at a frequency of 6.7 x 10(-8).

Streptococcus agalactiae: a vaginal pathogen?

The significance of Streptococcus agalactiae as an aetiological agent in vaginitis was evaluated. A total of 6226 samples from women who presented with vaginal symptoms was examined. The presence of >10 leucocytes/high-power field (h.p.f.) was taken to be the criterion of active infection. S. agalactiae was isolated from 10.1% of these samples. The isolation rates of other common pathogens such as Candida spp., Gardnerella vaginalis and Trichomonas spp. were 54.1%, 27.2% and 4.2%, respectively, in the same group of patients. In contrast, the isolation rates of these micro-organisms in the group of patients who had no infection (<10 leucocytes/h.p.f.) were 4.2%, 38.3%, 33% and 0.5%, respectively. In the majority of samples from which S. agalactiae was isolated, it was the sole pathogen isolated (83%) and its presence was associated with an inflammatory response in 80% of patients. Furthermore, the relative risk of vaginal infection with S. agalactiae (2.38) in patients with purulent vaginal discharge was greater than that of Candida spp. infection (1.41) and lower than that of Trichomonas spp. infection (8.32). These data suggest that S. agalactiae in symptomatic women with microscopic evidence of inflammation should be considered a causative agent of vaginitis.