Demographics, treatment and outcome of acute coronary syndromes: 17 years of experience in a specialized cardiac centre

BACKGROUND

Epidemiological information on patients with acute coronary syndromes managed in specialized cardiac centres is limited.

OBJECTIVE

To report the evolution of demographics, treatment and outcome of patients admitted to a tertiary coronary care unit (CCU) over a 17-year period.

METHODS

A prospective database of 18,719 patients admitted from April 1986 to March 2003 in a 21-bed CCU was analyzed.

RESULTS

From 1986 to 2003, the number of admissions increased from 937 to 1577 per year, while the length of stay declined from 7.5 to 3.5 days. The mean age increased from 58.4 to 63.4 years, and the proportion of men remained stable at approximately 70%. The use of coronary angiograms increased from 49.8% to 81.1% in all patients, while fibrinolysis dropped to 0.4%. In-hospital mortality decreased from 9% to 1.5%. The percentage of overall instrumentation (arterial line, central venous catheter, temporary pacemaker, Swan-Ganz catheter and intra-aortic balloon pump) decreased from 38% to 8.1%. From 1995 to 2003, the proportion of stenting during percutaneous transluminal coronary angioplasty increased dramatically from 0% to 86%. In the past five years, surgical revascularization has remained stable at approximately 20% of all admissions. The proportion of patients discharged with a noncoronary chest pain diagnosis has remained constant at approximately 4%.

INTERPRETATION

There has been a tremendous increase in efficiency, with an approximate doubling of the admissions turnover rate in a tertiary CCU. Patients with acute coronary syndromes are stratified faster and treated more invasively. Therapeutic advances are reflected by an almost linear 0.5% per year decrease in in-hospital mortality.

Finite element modeling of a progressively expanding shape memory stent

Cardiovascular stents are small cylindrical devices introduced in stenosed arteries to reopen the lumen and restore blood flow. However, this treatment presents complications, including restenosis, which is the reclosing of the artery's diameter after the insertion of a stent. The structure of the prosthesis penetrates into and injures the walls of the patient's artery. There then follows a proliferation of cells and the formation of scar tissue around the injury, similar to the scarring of other organic tissues. This reaction to the trauma subjects the artery to close. The proposed solution is to develop a Nitinol stent with a progressive expansion device made of polyethylene, allowing smooth and gradual contact between the stent and the artery's wall by creep effect. The purpose of this paper is to describe the technology and methodology for the numerical study of this kind of stent through the finite element method. ANSYS 8.0 software is used to perform the analysis. The Nitinol is modeled with a superelastic law and the polyethylene with a yield hardening law. A first simulation determines the final geometry of the stent laser cut from a small tube. A second simulation examines the behavior of the prosthesis during surgery and over the 4 weeks following the operation. The results demonstrate that a compromise can be reached between a limited expansion prior the inflation of the expandable balloon and a significant expansion by creep of the polymer rings.

Bleeding complications in patients with acute coronary syndrome undergoing early invasive management can be reduced with radial access, smaller sheath sizes, and timely sheath removal

OBJECTIVES

Our objective was to analyze the impact of arterial access site, sheath size, timing of sheath removal, and use of access site closure devices on high-risk patients with acute coronary syndromes (ACS).

BACKGROUND

In the SYNERGY trial, 9,978 patients with ACS were randomly assigned to receive enoxaparin or unfractionated heparin.

METHODS

This analysis includes 9,404 patients for whom sheath access information was obtained for the first PCI procedure or diagnostic catheterization. Comparisons of baseline, angiographic, and procedural characteristics were carried out according to access site and sheath size.

RESULTS

Overall, 9,404 (94%) patients underwent angiography at a median of 21 hr (25th and 75th percentiles: 5, 42) and 4,687 (50%) underwent PCI at a median of 23 hr (6,49) of enrollment. The access site was femoral for 94.9% of cases, radial for 4.4%, and brachial for 0.7%. Radial access was associated with fewer transfusions than femoral access (0.9% vs. 4.8%, P=0.007). For femoral access, the rates of noncoronary artery bypass grafting (CABG)-related TIMI major bleeding by sheath size was 1.5% for 4 or 5 French (Fr), 1.6% for 6 Fr, 3.3% for 7 Fr, and 3.8% for >or=8 Fr (P<0.0001). After adjustment for baseline characteristics, femoral access site, larger sheath size, and delayed sheath removal were independent predictors of need for transfusion.

CONCLUSIONS

Smaller sheaths, radial access, and timely sheath removal may mitigate the bleeding risk associated with potent antithrombotic/platelet therapy and early catheterization.

The vacuum cleft sign: an uncommon radiological sign

The intravertebral vacuum cleft sign (VCS) is an uncommon radiological sign, characterized by a radiolucent zone in the vertebral body. It is composed of 95% nitrogen and small amounts of oxygen and carbon dioxide. Post-traumatic ischemic necrosis could be its physiopathological mechanism, along with other pathologies like osteoporosis, corticosteroid therapy, diabetes, arteriosclerosis, alcoholism, multiple myeloma, bone metastasis and osteomyelitis. The broad diagnosis is made by antero-posterior X-ray, but computed tomography scan (CT scan) and magnetic resonance imaging (MRI) may help with the differential diagnosis. The aims of this paper are, on one hand, to communicate the clinical case of a 73-year-old osteoporotic woman with traumatic vertebral fractures who developed this sign in her radiological survey. On the other hand, its secondary aims are to review the medical literature about this sign and to show the clinical and radiological evolution after a percutaneous vertebroplasty.

Laboratory-acquired brucellosis

We report two laboratory-acquired Brucella melitensis infections that were shown to be epidemiologically related. Blood culture isolates were initially misidentified because of variable Gram stain results, which led to misdiagnoses and subsequent laboratory exposures. Notifying laboratory personnel who unknowingly processed cultures from brucellosis patients is an important preventive measure.

Human pituitary tumours express the bHLH transcription factors NeuroD1 and ASH1

Among the transcription factors involved in pituitary ontogenesis and physiology, basic helix-loop-helix (bHLH) have been poorly studied. Members of bHLH family include NeuroD1 and ASH1, both involved in neuroendocrine differentiation. We evaluated their mRNA expression patterns, by semi-quantitative RT-PCR analysis (sq-RT-PCR) and/or Northern blot, in a series of 33 pituitary adenomas (PA), anterior pituitaries, and pituitary cell lines. Immunohistochemistry for NeuroD1 was also performed in 25 PA. Low levels of NeuroD1 were observed in normal pituitaries and in the somatomammotroph cell lines GH3/GH4C1, contrasting with high levels in corticotroph AtT20 cells. NeuroD1 mRNA was widely expressed in PA (82%), with measurable levels found especially in those derived from Pit-1 independent lineages, i.e. corticotroph (5/5) and clinically non-secreting (CNS) adenomas (9/11). According to sq-RT-PCR analysis, overexpression of NeuroD1 compared to normal pituitaries was frequent. Variable nuclear NeuroD1 immunopositivity was also present in about 70% of studied cases. ASH1 mRNA was widely detected in normal pituitaries, in all tumour cell lines and in most PA (84%), with measurable levels in corticotroph (5/5) and CNS (9/11) adenomas, and in a significant subset of PA derived from Pit-1 dependent lineages (9/16). We conclude that: a) NeuroD1 is differentially expressed in PA and its possible ontogenetic and/or pathogenetic implications in non-corticotroph PA are discussed; b) ASH1 is a neuroendocrine marker whose expression is largely conserved in normal and neoplastic pituitary cells.

Endocardial cryotherapy as a novel strategy of improving myocardial perfusion in a patient with severe coronary artery disease

Patients with intractable angina pectoris due to end-stage coronary artery disease who are not amenable to conventional revascularization provide a therapeutic challenge. We describe the first published case of a young patient with intractable coronary artery disease that was successfully treated by endocardial cryotherapy.

Prognostic significance of elevated creatine kinase MB after coronary bypass surgery and after an acute coronary syndrome: results from the GUARDIAN trial

OBJECTIVE

To determine if the correlation between magnitude of creatine kinase-myocardial band release after coronary artery bypass surgery and 6-month mortality is comparable to that of patients admitted with an acute coronary syndrome.

METHODS

The GUARDIAN trial tested the efficacy of cariporide, an Na+/H+ exchange inhibitor, on reduction of myocardial ischemia or death in high-risk patients. We compared 6-month survival in a cohort of 2332 GUARDIAN patients scheduled for coronary artery bypass surgery at entry with 4233 acute coronary syndrome patients stratified by level of creatine kinase-myocardial band release. Cumulative 6-month survival by creatine kinase-myocardial band categories was performed using life table analysis, adjusting for variables known to impact prognosis using Cox regression.

RESULTS

The 6-month mortality rates for coronary artery bypass surgery patients with peak creatine kinase-myocardial band ratios of <1, > or =1 and <5, > or =5 and <10, and > or =10 upper limits of normal (ULN) were 5.8, 2.8, 5.9, and 12.0%, respectively (P <.0001). The 6-month mortality rates for acute coronary syndrome patients with peak creatine kinase-myocardial band ratios of <1, > or =1 and <5, > or =5 and <10, and > or =10 ULN were 6.3, 9.8, 10.0, and 12.3%, respectively (P <.0001). Patients with coronary artery bypass surgery or acute coronary syndrome had similar adjusted 6-month survival estimates at normal creatine kinase-myocardial band levels and when the creatine kinase-myocardial band level was > or =10 ULN. Patients with coronary artery bypass surgery had significantly better survival at intermediate enzyme levels (> or =1 and <10 ULN; P <.001).

CONCLUSIONS

Modest elevations of creatine kinase-myocardial band release (> or =1 and <10 ULN) after coronary artery bypass surgery are not associated with adverse 6-month survival, in contrast to that seen in acute coronary syndrome patients. Routine creatine kinase-myocardial band sampling should be considered in all higher-risk patients undergoing coronary artery bypass surgery procedures to identify the sizable cohort of patients with creatine kinase-myocardial band release > or =10 ULN; these patients may benefit from postoperative angiotensin-converting enzyme inhibitor and beta-blocker therapy. Newer cardioprotective agents that reduce the number of patients with marked creatine kinase-myocardial band release are currently being tested in large randomized controlled clinical trials.

[A clinical case of a giant lymphocele (LC) in a patient with a recent renal transplant is described]

BACKGROUND

The lymphocele (LC) described was associated with a sharp increase in plasma creatinine values, in the absence of any clinical symptoms. A open laparotomy procedure determined the resolution of the LC and the slow recovery of renal function. The huge dimensions of the LC (volume >3000 cc) and its pelvic localization, which dislocated both the bladder and the transplanted kidney, make this case unique, since the LC mimicked a particularly dilated bladder.

CONCLUSIONS

We discuss how therapies, rejection episodes, follow-up modalities, and surgical procedures may influence the onset of this frequent complication of renal transplantation.

In vivo measurement of coronary circulation angiotensin-converting enzyme activity in humans

Angiotensin-converting enzyme (ACE) is present on the luminal surface of the coronary vessels, mostly on capillary endothelium. ACE is also expressed on coronary smooth muscle cells and on plaque lipid-laden macrophages. Excessive coronary circulation (CC)-ACE activity might be linked to plaque progression. Here we used the biologically inactive ACE substrate (3)H-labeled benzoyl-Phe-Ala-Pro ([(3)H]BPAP) to quantify CC-ACE activity in 10 patients by means of the indicator-dilution technique. The results were compared with atherosclerotic burden determined by coronary angiography. There was a wide range of CC-ACE activity as revealed by percent [(3)H]BPAP hydrolysis (30-74%). The atherosclerotic extent scores ranged from 0.0 to 66.97, and the plaque area scores ranged from 0 to 80 mm(2). CC-ACE activity per unit extracellular space (V(max)/K(m)V(i)), an index of metabolically active vascular surface area, was correlated with myocardial blood flow (r = 0.738; P = 0.03) but not with measures of the atherosclerotic burden. These results show that CC-ACE activity can be safely measured in humans and that it is a good marker of the vascular area of the perfused myocardium. It does not, however, reflect epicardial atherosclerotic burden, suggesting that local tissue ACE may be more important in plaque development.

The application of cost effectiveness analysis to derive a formulary for urinary tract infections

According to economic principles an inappropriate prescription is the choice of an antimicrobial with higher/equivalent cost and lower effectiveness (or higher cost and equivalent/lower efficacy) than an alternative (in this case, the former is specified as a "dominated" drug). To identify cost-effective antibiotics we applied the principles of incremental cost-effectiveness analysis (ICEA) to microbiological data of San Bortolo Hospital. Its 27 wards were grouped in 9 functional areas. The resistance patterns of 8 urinary pathogens in the 1997 microbiology data base were assessed. The measure of antibiotic effectiveness was expressed as the percentage of isolates susceptible to each antibiotic tested. The difference in cost (i.e. the incremental change) between each antibiotic and the next more expensive alternative was calculated, and compared with the incremental change in effectiveness. Calculations were made for each pathogen. The antibiotics remaining after exclusion of all "dominated" antibiotics were pooled on a list defined as "Specific Area Formulary". The implications of the use of economic principles within a general antimicrobial policy are discussed.