Sex differences in patients with ischemia and no obstructive coronary disease subjected to intracoronary acetylcholine test in a multicenter registry

Background

Ischemia with no obstructive coronary disease (INOCA) is increasingly diagnosed because of wide performance of coronary angiography. Prevalence of INOCA is higher in women than in men, however the exact pathophysiological mechanisms which may explain this phenomenon are still not very well understood.

Objective

To evaluate differences in clinical and procedural characteristics between men and women with INOCA subjected to intracoronary acetylcholine test (Ach).

Methods

A total of 210 women and 148 men with INOCA diagnosed with coronary angiography, were prospectively enrolled in a multicenter, observational registry. Ach test was performed according to clinical indications in all included patients. After 1-year patients were re-evaluated for major cardiovascular events, angina symptoms and prescribed medical treatment.

Results

Mean age of 60.6±13.6 years old was similar in both populations, but differences were observed in the prevalence of risk factors: active smoking was more frequent among men (43% vs. 17%, p<0.001), who had also a higher number of associated risk factors (≥3 risk factors were present in 31.2% of men vs. 20.2% of women, p<0.01) and more frequent history of percutaneous coronary revascularization (14.2% vs. 6.7%, p=0.03). Women were more prone to have dyspnea than men (35.5% vs. 20.8%, p=0.01). Men had more coronary atherosclerosis in angiography (57.9% vs. 43.7%, p=0.01) and more slow flow in the left anterior descending artery (21.6% vs. 9.0%, p=0.001). Ach was positive in 36.5% of patients, similar in both sexes, with no differences in the type of induced coronary spasm. Among those with a positive Ach test, at one-year, 36% of women vs. 43.6% of men were on optimal medical treatment for vasospasm although the difference was not statistically significant. Importantly, 41.5% of women and 38.1% of men experienced severe symptoms of angina during follow-up.

Conclusions

Although men with INOCA have a higher risk profile than women and more coronary atherosclerosis, one third of patients present endothelial dysfunction, similar in both groups, indicating that probably other pathophysiological mechanisms are responsible for it in females. Treatment in these patients remains suboptimal and associated with highly impaired quality of life.

Funding Acknowledgement

Type of funding source: None

Clinical profile and predictors of positivity of acetylcholine test in patients with angina and no obstructive coronary artery disease. Results of a multi-center mediterranean registry

Background

Coronary endothelial dysfunction and vasospasm are potential causes of ischemia in no obstructive coronary disease (INOCA) and are now known to be associated with an increased risk of major cardiovascular events (MACE) and impaired quality of life. The recent guidelines recommend the use of intracoronary acetylcholine to unravel the underlying pathophysiology of INOCA, by identifying those with endothelial dysfunction, and to guide future treatment in these patients.

Objective

To evaluate the clinical profile and prevalence of endothelial dysfunction in patients with INOCA, and to identify the predictors of positivity of the acetylcholine test.

Methods

A total of 358 patients with INOCA were prospectively enrolled in a multicenter observational study. Coronary angiography and acetylcholine test were performed according to clinical indications in all included patients. Patients were followed-up for 1-year for MACE and clinical reevaluation of symptoms.

Results

Patients' mean age was 60.6±13.5 y.o. and 58.7% were females, with no previous history of coronary heart disease in 76% of cases. Regarding clinical presentation, 56.9% had angina at rest, 59.9% exertional angina, and 29.5% dyspnea. In 39% the EKG was abnormal, and in 10.9% there was a troponin rise.

Coronary endothelial dysfunction –defined as a vasoconstriction over 30%– was observed in 129 (36%) patients, and severe vasoconstriction (>70%) in 75 (21%). Of positive cases, 47 (36%) focal vasoconstriction, and 90 (70%) diffuse. On follow-up, patients with a positive Ach test were treated differently, with a lower prescription of betablockers (12% vs. 24%, p=0.01) and a higher use of vasodilators (47% vs. 28.5%, p=0.001). Guidelines-recommended optimal treatment was prescribed to 39.2% of patients with a positive acetylcholine test. Patients with positive acetylcholine test were more prone to having worsening angina (25.6% vs. 12.8%, p<0.01) and minimal exertion angina (40% vs. 26.7%, p=0.03) on follow-up. Multivariable regression analysis showed that acetylcholine test positivity was predicted by the presence of diabetes (OR 1.7, p=0.04), exertional angina (OR 1.2, p=0.04), coronary atherosclerosis (OR 1.8, p=0.02) and coronary milking (OR 2.6, p=0.04).

Conclusions

Endothelial dysfunction detected by acetylcholine test was present in one third of patients with INOCA and was associated with more severe and worsening symptoms. Although Ach test positivity influenced the pharmacological treatment at discharge, a large room for optimization still remained.

Funding Acknowledgement

Type of funding source: None

Usefulness of strain imaging to determine prognosis in pulmonary hypertension

Introduction

Pulmonary hypertension (PH) is defined as mean pulmonary arterial pressure (mPAP) ≥25 mmHg at rest, measured by right heart catheterization (RHC).

Purpose

To describe classical and myocardial deformation echocardiographic parameters in patients with established PH and to identify prognostic variables

Methods

We prospectively enrolled 76 patients with mPAP ≥25 mmHg undergoing RHC between 2017 and 2018. All subjects underwent transthoracic echocardiography (TTE) according to the latest ASE/EACVI guidelines the same day of the RHC. Strain analysis was carried out by speckle-tracking echocardiography (QLAB 10.7, Philips). Clinical events during the follow-up were: acute heart failure hospitalization, cardiac transplant and all-cause mortality.

Results

Mean age was 59±12, 43.4% were women and 49 patients (64.5%) belonged to group 2 of PH. The median follow-up was 288 (ICR 92–534) days. Total number of events was 42 (55.3%, 9 deaths). Variables associated to events are shown in Table 1. All classic LV and RV systolic function and strain parameters were associated with a worse prognosis, being free-wall RV longitudinal strain (RVLS) the only one that remained as a prognostic factor in mutivariate analysis. Other variables associated with a worse prognosis were PCP>15 mmHg and NT-proBNP>1800, the latter being independent predictor of events. The attached figure shows event-free survival curves for the global population divided according to whether or not they belong to group II PH.

Conclusions

Our data highlight the prognostic value of free-wall RVLS and NT-proBNP in patients with established PH. NT-ProBNP was only useful in group II PH while free-wall RVLS identified patients with a higher risk of events in both groups, mainly in patients with heart disease

Free event survival Curves

Funding Acknowledgement

Type of funding source: None

Concurrent interspecies and clonal dissemination of OXA-48 carbapenemase

Several isolates of four different carbapenemase-producing Enterobacteriaceae species were recovered from a patient hospitalized for 4 months in a teaching hospital in Madrid. These species comprised seven Klebsiella pneumoniae belonging to ST15, four Escherichia coli belonging to ST2531, two Serratia marcescens and one Citrobacter freundii. This patient was the index case of a small outbreak of four patients infected and/or colonized by carbapenemase-producing K. pneumoniae. Molecular results identified the bla(OXA-48) gene in all Enterobacteriaceae isolates from the index case and in all isolates from the other three patients, suggesting intra- and interpatient dissemination. Our results highlight the great ability of OXA-48 carbapenemase to spread among different enterobacterial species by both clonal and nonclonal dissemination.

Design of clone-specific probes from genome sequences for rapid PCR-typing of outbreak pathogens

The genome sequence of one OXA-48-producing Klebsiella pneumoniae belonging to sequence type (ST) 405, and three belonging to ST11, were used to design and test ST-specific PCR assays for typing OXA-48-producing K. pneumoniae. The approach proved to be useful for in-house development of rapid PCR typing assays for local outbreak surveillance.

Prevalence and molecular epidemiology of acquired AmpC β-lactamases and carbapenemases in Enterobacteriaceae isolates from 35 hospitals in Spain

The purpose of this investigation was to determine the prevalence of plasmid-mediated AmpC (pAmpC) and carbapenemases in Enterobacteriaceae collected from 35 hospitals in Spain and to establish their epidemiological relationships. We conducted a prospective multi-centre study on pAmpC- or carbapenemase-producing Enterobacteriaceae isolates from clinical samples collected from February to July 2009. The strains suspected to carry pAmpC were resistant or showed intermediate susceptibility to co-amoxiclav and second- or third-generation cephalosporins. Strains suspected to carry a carbapenemase were selected because they showed a minimum inhibitory concentration (MIC) to imipenem >1 mg/L. Polymerase chain reaction (PCR) and a sequencing strategy were used to characterise the enzymes. The clonal relationships between isolates was analysed by pulsed field gel electrophoresis (PFGE). Among 100,132 Enterobacteriaceae isolates collected, 1,654 were compatible with the production of pAmpC or carbapenemases. We found a prevalence of 0.64 % of pAmpC (n = 635) and 0.04 % of carbapenemases (n = 43). The most prevalent pAmpC enzymes were CMY-type (78.3 %), DHA-type (19.5 %), ACC-type (1.6 %) and FOX-type (0.6 %). The CMY-type was the most frequent in Escherichia coli and Proteus mirabilis species, whereas the DHA-type was mainly found in Klebsiella spp. The enzymes involved in carbapenem resistance were VIM-1, IMP-22 and the new IMP-28. Nine new bla genes were described: bla (CMY-54), bla (CMY-55), bla (CMY-56), bla (CMY-57), bla (CMY-96), bla (DHA-6), bla (DHA-7), bla (FOX-8) and bla (IMP-28). The prevalence of pAmpC or carbapenemases found is not negligible. The CMY-types were the predominant pAmpC, whereas the VIM or IMP enzymes were the predominant carbapenemases. Furthermore, we observed a great genetic diversity among pAmpC-producing strains and a close clonal relationship between carbapenemase-producing strains.

Increase of resistance to macrolides in invasive Streptococcus pneumoniae in Spain (2000-2001)

This study examined the antimicrobial resistance of 1,278 invasive Streptococcus pneumoniae isolates from 41 Spanish laboratories participating in the European Antimicrobial Resistance Surveillance System (EARSS) during 2000 and 2001. Twenty-nine laboratories participated during both years and provided 950 of the isolates. Each laboratory used its own susceptibility testing methods. External quality assessment was performed annually by each participating laboratory. Significant increases in penicillin and erythromycin resistance were observed between 2000 and 2001. This increase was particularly noticeable in isolates from the laboratories participating during both years and in isolates from children and elderly patients.

Significant increase in the prevalence of erythromycin-resistant, clindamycin- and miocamycin-susceptible (M phenotype) Streptococcus pyogenes in Spain

In 1998 we conducted a multicentre study in Spain on the susceptibility of Streptococcus pyogenes isolates to different 14-, 15- and 16-membered macrolides and clindamycin, in which the number of strains examined was proportional to the number of inhabitants in each geographical area. The aim of the present work was to re-examine the antimicrobial susceptibility of S. pyogenes in 2001, using the same methodology and centres as in 1998, to determine the different susceptibility phenotypes to macrolides-lincosamides, and to compare the results from the 2 years by statistical tests. A total of 529 unique isolates of S. pyogenes, collected in 21 laboratories, were studied. Throat swabs provided 417 isolates (78.8%), and the remaining 112 were from other sources. Four hundred and thirty-five (82.2%) were isolated from children and 94 (17.8%) from adults. One hundred and fifty-seven (29.7%) of the isolates were resistant to erythromycin and azithromycin, whereas resistance to miocamycin, a 16-membered macrolide, was 1.5%. The prevalence of resistance to clindamycin was 1.3%. The majority (98.7%) of the 157 erythromycin-resistant strains presented the M phenotype. When we compared the results obtained in 1998 and 2001, we observed a statistically significant increase in resistance to erythromycin and azithromycin (P = 0.02, chi(2) test), but not to clindamycin or miocamycin (P = 0.47, chi(2) test with Yates' correction). The significant increase in the prevalence of resistance to some macrolides of S. pyogenes in Spain underscores the need for continuous surveillance of antimicrobial resistance in this species.

Antibiotic resistance in 1962 invasive isolates of Escherichia coli in 27 Spanish hospitals participating in the European Antimicrobial Resistance Surveillance System (2001)

In Europe, antimicrobial resistance of invasive pathogens has been monitored since 1998 by the European Antimicrobial Resistance Surveillance System (EARSS). The goal of this study is to analyse the susceptibility data of invasive Escherichia coli collected by 27 Spanish laboratories in 2001. Each laboratory identified strains and tested their susceptibility using its own methods. To assess the comparability of susceptibility test results, a quality assurance exercise was performed. We report data from 1962 invasive isolates of E. coli: 1959 from blood and three from cerebrospinal fluid, corresponding to the same number of patients. Resistance to ampicillin, co-trimoxazole, ciprofloxacin and gentamicin was found in 58.46%, 32.91%, 17.19% and 6.39% of isolates, respectively. Extended-spectrum beta-lactamase (ESBL) production was detected in 30 strains (1.55%). Ciprofloxacin resistance was higher in isolates from men and in-patients than in those from women and out-patients (P < 0.001). Resistance to ampicillin and co-trimoxazole was more widespread in children than in adults: 70.37% versus 57.87% (P = 0.01) and 41.84% versus 32.53% (P = 0.05). Non-significant differences in resistance to fluoroquinolones were observed between isolates from children (11.1%) and adults (17.54%), despite the fact that fluoroquinolones are not administered to children. Significantly, resistance to non-beta-lactam antibiotics (co-trimoxazole, ciprofloxacin and gentamicin) was more prevalent in ampicillin-resistant strains and ESBL-producing strains than in ampicillin-susceptible strains and non-ESBL-producing strains. Multidrug resistance was present in 13.92% of isolates; the most prevalent phenotype was resistance to ampicillin, co-trimoxazole and ciprofloxacin, which was detected in 59.36% of multiresistant strains and in 8.22% of strains overall.

Susceptibility of strains of Streptococcus agalactiae to macrolides and lincosamides, phenotype patterns and resistance genes

The Group B streptococcus (Streptococcus agalactiae) is a pathogen of increasing importance in human disease. We therefore studied the susceptibility of clinical isolates of S. agalactiae to penicillin G, erythromycin, azithromycin and clindamycin using National Committee for Clinical Laboratory Standards methodology, and we also determined the phenotypes of macrolide-lincosamide susceptibility and the resistance genes implicated in a group of selected isolates of the different phenotypes. We used 221 isolates collected between 1997 and 1999 in two Health Authority Areas in Móstoles and Granada, Spain. The minimal concentration for 90% inhibition (MIC90) for penicillin G was 0.12 mg/L and all the isolates tested were susceptible. One hundred and eighty-five (83.7%) were susceptible to erythromycin and azithromycin and 191 (86.4%) were susceptible to miocamycin and clindamycin. Twenty-three isolates (10.4%) had a constitutive MLSB phenotype, seven (3.2%) an inducible phenotype, and six (2.7%) an M phenotype. All except one of the MLSB phenotype isolates tested (n = 23) carried erm genes; in two strains with the mef (A) gene, all the M phenotype (n = 6) isolates tested carried mef genes, while erm and mef (A) genes were absent in all the macrolide-lincosamide-susceptible (n = 12) isolates tested. In our environment, resistance to macrolide and lincosamide in S. agalactiae was present in 10-16% of the isolates. The majority of resistant strains had the MLSB phenotype.

Bacteremia by Dermabacter hominis, a rare pathogen

Dermabacter hominis is a gram-positive, catalase-positive, glucose-fermenting rod, which, as it grows forms small greyish-white colonies with a characteristic pungent odor. Previously known as coryneform Centers for Disease Control and Prevention groups 3 and 5, it was catalogued as D. hominis in 1994. Various strains isolated in blood cultures, abscesses, or wounds in the 1970s were retrospectively characterized in referral centers as D. hominis. In this report we describe two patients with severe underlying pathology who developed bacteremias by D. hominis within the context of their clinical pictures.

[Significant bacteremias by Corynebacterium amycolatum: an emergent pathogen]

BACKGROUND

Corynebacterium sp. is an extremely varied genus which includes little known species and of which only Corynebacterium diphteriae, Corynebacterium urealyticum and Corynebacterium jeikeium are considered indisputable pathogens. Other species, such as C. amycolatum are at present being reconsidered as causative agents in infectious pathologies, partly on account of our greater aquaintance and improved identification techniques for these microorganisms and partly on account of the growing number of immunocompromised patients in whom all their pathogenic capacity is usually able to develope. We present 3 cases of significant bacteremia by C. amycolatum.

METHODS

Bacterial isoliations from blood culture were obtained using the Vital Systems. Identification was performed by means of Gran stain, colony morphology, the results of numerous biochemical tests (including the Api Coryne systems), the behaviour of the strains against the vibriostatic agent O/129 and the antibiotic susceptibility pattern obtained with the E-test.

RESULTS

The three isolates of C. amycolatum were obtained from patients after a lenghtly hospitalization, multi-instrumentation and who had severe underlying disease. All three presented with concomitant isolates of C. amycolatum from other sites: sputum, wound and catheter respectively, which could explain the origin of the bacteremia. Colony morphology, antibiotic susceptibility patterns, resistance to the vibriostatic agent O/129 and the results of the biochemical test carried out were similar to those previously describe in the literature.

CONCLUSIONS

C. amycolatum should be born in mind as a agent responsable for significant and severe pathology in this type of patient. In addition, it as certain specific characteristics which assits in its identification in the normal micr

Antimicrobial resistance of Streptococcus pneumoniae isolates in 1999 and 2000 in Madrid, Spain: a multicentre surveillance study

Resistance to first-line antimicrobial agents in Streptococcus pneumoniae is increasing worldwide and the new fluoroquinolones may provide a good alternative. The antimicrobial susceptibility to levofloxacin and 13 other antibiotics of 300 isolates of S. pneumoniae, isolated in the Madrid community in 1999 and 2000, was determined. A total of 65.6% of isolates were penicillin intermediate or resistant strains. A high percentage of resistance to macrolides, clindamycin, tetracycline and chloramphenicol was also observed, mainly in penicillin-resistant strains. All but one strain was susceptible to levofloxacin.

High prevalence of erythromycin-resistant, clindamycin/miocamycin-susceptible (M phenotype) Streptococcus pyogenes: results of a Spanish multicentre study in 1998. Spanish Group for the Study of Infection in the Primary Health Care Setting

Using the standard agar dilution method we studied the prevalence of susceptibility to 14-, 15- and 16-membered ring macrolides and clindamycin in Streptococcus pyogenes isolated in 1998 from 21 laboratories in Spain. The number of strains admitted to the study was proportional to the numbers of inhabitants in each geographical area. We also determined the susceptibility phenotypes and the genetic basis for the antibiotic resistance. A total of 486 unduplicated isolates of S. pyogenes were used. Throat swab samples provided 359 (73.9%) isolates, and the remaining 127 isolates were from other sources. One hundred and fourteen (23.5%) isolates were resistant to erythromycin, a 14-membered ring macrolide, and azithromycin, a 15-membered macrolide, whereas only 1% of isolates were resistant to miocamycin, a 16-membered macrolide and 0.8% were resistant to clindamycin. Of the 114 erythromycin-resistant strains, 109 (95.6%) were susceptible to clindamycin and miocamycin. Since induction with erythromycin did not modify susceptibility to the latter antibiotics, these 109 strains were considered to have the M phenotype. Twenty strains with the M phenotype, one per laboratory, were assayed by PCR and showed the presence of the mef gene, which is responsible for antibiotic resistance by an efflux system. Among comparable studies covering entire countries, ours demonstrates one of the highest rates of S. pyogenes erythromycin resistance and clindamycin and miocamycin susceptibility in the world. Strains with the M phenotype account for the great majority of these isolates.

High prevalence of resistance to clindamycin in Bacteroides fragilis group isolates

Susceptibility to anti-anaerobic agents in the Bacteroides fragilis group varies according to the geographical region studied. In recent years there has been a reduction in the susceptibility of such isolates, particularly to antibiotics such as clindamycin and cefoxitin. The antimicrobial susceptibilities of 100 isolates of the B. fragilis group isolated in 1998 from faecal samples of healthy people to clindamycin and five other anti-anaerobic agents were determined. Meropenem, metronidazole and trovafloxacin showed excellent activity against all isolates. The efficacy of cefoxitin was low, with only 46% of isolates susceptible. A high prevalence of resistance to clindamycin (49% of isolates) was observed.

Drug efflux and parC mutations are involved in fluoroquinolone resistance in viridans group streptococci

Nine ciprofloxacin-resistant viridans group streptococci isolated from asymptomatic carriers were analyzed. Identification to the species level by using three different commercial systems and a PCR-based approach was inconsistent. The nucleotide sequences of fragments of the parC, parE, gyrA, and gyrB genes showed considerable intra- and interspecies variations, and these variations mainly involved silent mutations. Three isolates had changes in Ser-79 of ParC (to Phe or Tyr). Phenotypic characterization indicated that eight of the nine isolates had a putative efflux mechanism that would confer low-level resistance to ciprofloxacin.