Long term clinical outcomes after deployment of femoral vascular closure devices in coronary angiography and percutaneous coronary intervention

BACKGROUND

We evaluated the long term clinical outcomes of femoral vascular closure devices following its deployment in coronary angiography and percutaneous coronary intervention (PCI) procedures.

METHODS

From June 2000 to September 2004, 265 patients who received femoral vascular closure devices after coronary angiography and PCIs were enrolled into the study. Patients' medical records were reviewed and vascular complications within 1 year of follow-up period were recorded. Rutherford's categories of claudication were used to quantify different degrees of claudication and leg ischaemia. Duplex ultrasonography of both femoral arteries (using the nonaccessed site as control) was performed at 1 year after deployment of vascular closure devices. Vessel diameter and flow velocities for both common femoral arteries were obtained.

RESULTS

There was no occurrence of late vascular complications like arteriovenous fistula, pseudoaneurysm, surgical repair of access site complications, late groin bleeding and infection. By Rutherford categories of claudication, 99.2% of patients had grade 0 claudication while the remaining 0.8% was in grade 1. By arterial Duplex ultrasonography, the peak systolic velocity of the accessed femoral artery (predominantly right side) was nonsignificantly higher, 94.9 + or - 26.0 cm/s when compared to 91.5 + or - 24.8 cm/s in the control site (P = 0.12). As for vessel diameter, no significant difference was found in the mean end-diastolic vessel diameter 8.8 + or - 1.3 mm (puncture site) versus 8.7 + or - 4.4 mm (control site) (P = 0.72).

CONCLUSION

We found that the use of femoral closure devices was safe and it was not associated with any adverse long term vascular complications.

Isolated left ventricular non-compaction: an unusual indication for heart transplantation

We report a patient with isolated left ventricular non-compaction diagnosed by echocardiography and cardiac magnetic resonance imaging. She developed refractory congestive heart failure and subsequently underwent successful heart transplantation. This type of cardiomyopathy is thought to be caused by the arrest of normal embryogenesis of the endocardium and myocardium. The spectrum of clinical, radiological, and pathological abnormalities is discussed.

Synthesis and characterization of CdSe nanorods using a novel microemulsion method at moderate temperature

CdSe nanoparticles have been successfully synthesized using a novel microemulsion method at moderate temperature. It is found that with a combination of the surfactant AOT and hydrazine hydrate, it is possible to control the morphology of the nanoparticles. The hydrazine hydrate acts as both a reducing agent and a templating agent that favors the formation of a rodlike structure. The composition, morphology and optical properties of the CdSe nanoparticles were investigated using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) absorption spectroscopy, photoluminescence (PL) spectroscopy, energy dispersive X-ray spectroscopy (EDX) and Fourier transform infrared (FT-IR) spectroscopy. The nucleation and growth mechanism for this system is also proposed based on a time-dependent study. This synthesis route provides a moderate temperature (100 degrees C) method for synthesizing rodlike CdSe, hence reducing the possibility of oxidation of this chalcogenide compound.

Controlled synthesis and association behavior of graft Pluronic in aqueous solutions

Poly(vinyl pyrrolidone) (PVP) was grafted onto Pluronic F127 (PEO-PPO-PEO) to produce novel amphiphilic PVP-g-F127 graft copolymers. A controlled synthesis method was used to graft PVP onto different parts of F127. Two types of graft polymers were obtained: one has PVP grafted onto the PEO part of F127 and the other has PVP grafted onto the PPO part of F127. The association behavior of the two modified polymers was examined using differential scanning calorimetry, surface tension measurements, and dynamic light scattering.

Study of mixed micelles and interaction parameters for polymeric nonionic and normal surfactants

Surface tension (ST) measurements were carried out on various binary mixtures of the "normal" surfactants, such as nonionic surfactant, hexaethylene glycol mono-n-dodecyl ether(C12EO6), and cationic surfactant, tetradecyltrimethylammonium bromide (TTAB), and polymeric copolymer, Pluronic F127, F127(PPO)-g-PVP, and F127(PEO)-g-PVP. In all cases mixed micellar aggregates were formed and critical micellar concentrations of binary mixtures containing different mole fractions of the surfactants were measured using surface tension measurement. In the region where mixed micelles are formed, the interaction of two "normal" surfactants and three "polymeric" nonionic surfactants showed synergistic behavior and the results were analyzed using a interaction parameter, beta, which characterized the interaction in the mixed micelle and introduced by a regular solution theory. The regular solution theory can be applied to describe the interaction between TTAB and C12EO6, and graft polymeric surfactants systems. The results discussed in this paper indicated that regular solution theory has broader extent of application.

A case of takotsubo cardiomyopathy: transient left ventricular apical ballooning

A 78-year-old woman was admitted to hospital with central chest pain and the electrocardiographic and cardiac marker changes typical of acute anterior myocardial infarction. Coronary angiography revealed normal epicardial coronary arteries, and left ventriculography showed apical akinesis as well as basal hyperkinesis. This is a case of transient left ventricular apical ballooning or takotsubo cardiomyopathy, possibly attributable to catecholamine-mediated myocardial stunning.

Poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide)-g-poly(vinylpyrrolidone): association behavior in aqueous solution and interaction with anionic surfactants

In this work, we aimed to study the association and interaction behavior of poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) block copolymers grafted with poly(vinylpyrrolidone). Critical micellization concentrations were determined using fluorescent probes (pyrene) and critical micellization temperatures characterizing temperature-dependent transitions from monomers to multimolecular micelles were measured. The thermal responsiveness of the copolymer is not affected by the grafting. The hydrodynamic radius of the graft copolymer micelles is found to be greater than that of the original copolymer micelles. The graft copolymer is found to form anisotropic aggregates. The structure of the graft copolymer micelles is less disrupted by the anionic surfactant sodium dodecyl sulfate, compared to the ungraft copolymer.

Anomalous origin of right coronary artery from the left coronary sinus: incidence, characteristics, and a systematic approach for rapid diagnosis

Twenty-three patients were found to have anomalous origin of right coronary artery from the left coronary sinus (LCS) from January 2000 to October 2003. The mean age was 58.6+/-14.3 years with male predominance (56.5%). Cardiovascular risk factors were found in 18 (78.3%) patients while coronary artery disease was seen in 13 (56.5%) patients. Among the coronary artery disease patients, the left anterior descending artery was the most commonly involved, followed by the right coronary artery and the left circumflex artery. Right coronary artery dominance was seen in 19 (82.6%) patients. The anomalous right coronary artery originates within the left coronary sinus in 17 (73.9%) patients while from the left aortic wall above the sinus in 6 (26.1%) patients only. Congenital heart disease and acquired valvular heart disease were the most common associated conditions. The author will share his experience and suggest a four-step approach of early recognition and selection of the anomalous right coronary artery ostium. Using the suggested strategy, most of the anomalous right coronary artery could be opacified with a left amplatz 1 catheter. Aortogram was needed only in 47.8% of cases.

Multiple brain abscesses in a patient with bilateral pulmonary arteriovenous malformations and immunoglobulin deficiency

A 34 year old Chinese man presented with grand mal seizures complicating multiple brain abscesses caused by mixed oral flora. Because of persistent hypoxaemia contrast spiral thoracic computed tomography was done, which revealed bilateral pulmonary arteriovenous malformations (PAVMs). Concomitant IgA and IgG subclass deficiency was also found. The combination of these two conditions appears to have predisposed this patient to presumably paradoxical septic embolism. The patient's cerebral condition responded to postoperative antibiotic treatment and he eventually received selective coil embolisation of right lower lobe PAVMs, which relieved his hypoxaemia and dyspnoea.

Tissue Doppler echocardiographic evidence of reverse remodeling and improved synchronicity by simultaneously delaying regional contraction after biventricular pacing therapy in heart failure

BACKGROUND

Biventricular pacing has been proposed to improve symptoms and exercise capacity in patients with advanced heart failure and wide electrocardiographic wave complexes. This study investigated the effect of biventricular pacing on reverse remodeling and the underlying mechanisms.

METHODS AND RESULTS

Twenty-five patients with NYHA class III to IV heart failure and electrocardiographic wave complex duration >140 ms receiving biventricular pacing therapy were assessed serially up to 3 months after pacing and when pacing was withheld for 4 weeks. Tissue Doppler echocardiography was performed using a 6-basal, 6-mid segmental model to assess the time to peak sustained systolic contraction (T(S)). There was significant improvement of ejection fraction, dP/dt, and myocardial performance index; decrease in mitral regurgitation, left ventricular (LV) end-diastolic (205+/-68 versus 168+/-67 mL, P<0.01) and end-systolic volume (162+/-54 versus 122+/-42 mL, P<0.01); and improved 6-minute hall-walk distance and quality of life score after pacing for 3 months. The mechanisms of benefits were as follows: (1) improved LV synchrony, as evident by homogeneous delay of T(S) to a timing close to the latest (usually the lateral) segment abolishing the intersegmental difference in T(S) and decreasing the standard deviation of T(S) within the left ventricle (37.7+/-10.9 versus 29.3+/-8.3 ms, P<0.05); (2) improved interventricular synchrony; and (3) shortened isovolumic contraction time (122+/-57 versus 82+/-36 ms, P<0.05) but increased diastolic filling time. These benefits are pacing dependent, because withholding the pacing resulted in varying speeds in the loss of cardiac improvements.

CONCLUSIONS

Biventricular pacing reverses LV remodeling and improves cardiac function. Improvement of LV mechanical synchrony seems to be the predominant mechanism.

Comparison of digoxin versus low-dose amiodarone for ventricular rate control in patients with chronic atrial fibrillation

1. Rapid ventricular rate (VR) and rhythm irregularity during atrial fibrillation (AF) impair cardiac performance. Although digoxin has been widely used in patients with AF, its efficacy for the control of VR and rhythm irregularity is unsatisfactory. Whether low-dose amiodarone is more effective remains unclear. 2. We randomized 16 patients (13 male, three female; mean (+/-SD) age 63 +/- 9 years) with chronic AF to receive either digoxin or amiodarone for 24 weeks. At baseline and at 12 and 24 weeks follow up, Holter monitor recording and cardiopulmonary exercise test were performed to assess VR and rhythm irregularity control and exercise capacity. 3. Seven and nine patients received digoxin and amiodarone, respectively. After 12 and 24 weeks treatment, both digoxin and amiodarone significantly decreased the mean ambulatory VR and the VR during peak exercise compared with baseline (all P < 0.05). At 24 weeks, there were no significant differences between digoxin and amiodarone in the percentage reduction in VR during ambulatory (27 +/- 13 vs. 25 +/- 12%, respectively; P = 0.8) and peak exercise (13 +/- 12 vs. 12 +/- 10%%, respectively; P = 0.6). 4. The rhythm irregularity, as measured by SD of RR intervals and the root mean square of the SD of RR intervals, and the exercise capacity, as measured by exercise workload, maximal oxygen consumption (VO2), minute ventilation, ventilatory equivalent and oxygen pulse, were not significantly changed after treatment with digoxin or amiodarone (all P > 0.05). 5. Quality of life, determined by SF-36 questionnaire, and AF symptomatology, as measured by the AF Symptom Checklist, were also not significantly changed after treatment with digoxin or amiodarone (all P > 0.05). 6. In conclusion, digoxin and low-dose amiodarone had similar efficacy in the control of VR during ambulatory activity and exercise. However, both were less efficacious during exercise and did not significantly affect rhythm irregularity, exercise capacity, quality of life and AF symptomatology in patients with chronic AF.

Continuous calcium chloride infusion for massive nifedipine overdose

A 37-year-old woman presented with persistent hypotension and noncardiogenic pulmonary edema after massive nifedipine overdose. Judicious use of continuous and prolonged high-dose IV calcium infusion was administered to provide sustained increases in serum ionic calcium level (approximately 2 mmol/L) and was able to improve the hemodynamic status without any major adverse reaction.

Bilateral massive adrenal hemorrhage. Assessment of putative risk factors by the case-control method

Case reports and case series have identified putative risk factors for the development of bilateral massive adrenal hemorrhage (BMAH) in humans. The anatomy and physiology of the adrenal gland allow development of a model to fit the pathophysiology behind these risk factors. Until now, these risk factors were not systematically tested using analytical epidemiologic studies. A case-control study was undertaken using sources of cases and controls from multiple teaching hospitals in Ontario, Canada. The results of multivariate logistic regression indicated that thrombocytopenia (odds ratio [OR] = 14.6, 95% confidence intervals [CI] = 3.0-70.1, p < 0.001), heparin exposure of any route or type beyond 3 days (4-6 days: OR = 17.0, CI = 1.9-154.6; > 6 days: OR = 33.5, CI = 4.3-262.6; p < 0.001), and sepsis (OR = 6.3, CI = 1.2-32.2, p = 0.019) were most strongly and independently associated with development of BMAH. Another weaker positive association included invasive radiologic procedure (OR = 4.4, CI = 0.9-22.1, p = 0.055). Neither major surgery or duration of hospitalization were independent risk factors. Although coronary artery disease and possibly diabetes and hypertension appeared to be markers for lower risk of BMAH, this may be a result of bias introduced by using hospital controls ("Berkson bias"), as the effect was not explained by a protective effect of vasoactive medications. Thus, a picture of the high-risk patient should include a patient who has been treated with heparin (any route or type) beyond 3 days and has had thrombocytopenia (not necessarily induced by heparin) during the course of an illness. If the setting includes unexplained abdominal, chest, or back pain; fever; confusion; hypotension or shock; abrupt anemia; or electrolyte disorders, clinicians should not hesitate to cover empirically with lifesaving glucocorticoids while awaiting results of confirmatory tests.

Reversal of left ventricular remodeling by synchronous biventricular pacing in heart failure

Synchronous biventricular pacing is a new nonpharmacological supplemental treatment of advanced heart failure associated with electromechanical conduction delay. However, the role of pacing on left ventricular remodeling is unknown. Eleven patients with New York Heart Association Class III to IV heart failure, a left ventricular ejection fraction < 35%, and a QRS duration > or = 140 ms received a biventricular dual chamber pacemaker. Serial echocardiography, 6-minute hall walk, and Minnesota Living with Heart Failure quality-of-life (QOL) questionnaire were performed before and after up to 3 months of pacing. At 3 months there was a significant increase in fractional shortening (P < 0.001), ejection fraction (P < 0.001), and cardiac output (P < 0.05). The left ventricular end-diastolic volume (245 +/- 70 vs 185 +/- 37 mL, P < 0.05), end-systolic volume (209 +/- 69 vs 140 +/- 44 mL P < 0.05), and mitral regurgitation were reduced (P < 0.05), and diastolic filling time was lengthened (P < 0.05). There were also improvements in heart failure symptoms, an increase in 6-minute walk distance, and a decrease in QOL scores. Synchronous biventricular pacing for 3 months was associated with hemodynamic improvements, reversal of left ventricular remodeling, and increase in left ventricular systolic function, and a decrease in secondary mitral regurgitation.

A single nucleotide polymorphism at nucleotide -1793 in the von Willebrand factor (VWF) regulatory region is associated with plasma VWF:Ag levels

von Willebrand Factor (VWF) is a large multimeric glycoprotein involved in the transport and protection of factor VIII and in mediating platelet-subendothelium and platelet-platelet interactions. We have documented the presence of a single nucleotide polymorphism (SNP) at nucleotide (nt) -1793 (G 0.36 or C 0.64) in the VWF 5'-flanking sequence. This polymorphism is in strong linkage disequilibrium with the previously reported SNPs at nts -1234, -1185 and -1051 and, like this other group of polymorphisms, shows a significant association with plasma VWF levels. This association is more marked in subjects who are more than 40 years of age. Further, circumstantial evidence to support a role for the -1793 sequence in regulating VWF expression comes from our demonstration of differential binding of endothelial cell nuclear proteins, including the transcription factor NFkappaB, by this sequence. In summary, the association of the -1793 SNP with plasma VWF levels provides additional evidence for the role of the VWF regulatory region between nts -1793 and -1051 in controlling VWF expression.

Variation at the von Willebrand factor (vWF) gene locus is associated with plasma vWF:Ag levels: identification of three novel single nucleotide polymorphisms in the vWF gene promoter

Both genetic and environmental factors contribute to the normal population variability of plasma von Willebrand Factor (vWF) levels, however, regulatory mechanisms at the vWF gene locus itself have not yet been identified. We have investigated the association between polymorphic variation in the 5'-regulatory region of the vWF gene and levels of plasma vWF:Ag in a study of 261 group O blood donors. Three novel single nucleotide polymorphisms (SNPs) were identified in the vWF promoter: C/T at -1234, A/G at -1185, and G/A at -1051. These SNPs had identical allele frequencies of 0.36 for the -1234C, -1185A, and -1051G alleles and 0.64 for the -1234T, -1185G, and -1051A alleles and were in strong linkage disequilibrium. In fact, these polymorphisms segregated as two distinct haplotypes: -1234C/-1185A/-1051G (haplotype 1) and -1234T/-1185G/-1051A (haplotype 2) with 12.6% of subjects homozygous for haplotype 1, 40. 6% homozygous for haplotype 2, and 42.5% of subjects heterozygous for both haplotypes. Only 4.3% of individuals had other genotypes. A significant association between promoter genotype and level of plasma vWF:Ag was established (analysis of covariance [ANCOVA], P =. 008; Kruskal-Wallis test, P =.006); individuals with the CC/AA/GG genotype had the highest mean vWF:Ag levels (0.962 U/mL), intermediate values of vWF:Ag (0.867 U/mL) were observed for heterozygotes (CT/AG/GA), and those with the TT/GG/AA genotype had the lowest mean plasma vWF:Ag levels (0.776 U/mL). Interestingly, when the sample was subgrouped according to age, the significant association between promoter genotype and plasma vWF:Ag level was accentuated in subjects > 40 years of age (analysis of variance [ANOVA], P =.003; Kruskal-Wallis test, P =.001), but was not maintained for subjects </= 40 years of age (ANOVA, P >.4; Kruskal-Wallis test, P >.4). In the former subgroup, mean levels of plasma vWF:Ag for subjects with the CC/AA/GG, CT/AG/GA, and TT/GG/AA genotypes were 1.075, 0.954, and 0.794 U/mL, respectively. By searching a transcription factor binding site profile database, these polymorphic sequences were predicted to interact with several transcription factors expressed in endothelial cells, including Sp1, GATA-2, c-Ets, and NFkappaB. Furthermore, the binding sites at the -1234 and -1051 SNPs appeared to indicate allelic preferences for some of these proteins. Electrophoretic mobility shift assays (EMSAs) performed with recombinant human NFkappaB p50 showed preferential binding of the -1234T allele (confirmed by supershift EMSAs), and EMSAs using bovine aortic endothelial cell (BAEC) nuclear extracts produced specific binding of a nuclear protein to the -1051A allele, but not the -1051G allele. These findings suggest that circulating levels of vWF:Ag may be determined, at least in part, by polymorphic variation in the promoter region of the vWF gene, and that this association may be mediated by differential binding of nuclear proteins involved in the regulation of vWF gene expression.

Technical note: CT determination of the mineral density of dry bone specimens using the dipotassium phosphate phantom

Recent studies have demonstrated the potential application of computed tomography (CT) in research into bone density. Clinical studies of bone density using CT commonly employ a dipotassium phosphate phantom to calibrate measurements of mineral density. Designed for in vivo studies, the use of this phantom requires that bones be scanned while immersed in and permeated by fluids or soft tissues similar to water in X-ray attenuation coefficient. However, this condition may not always be met in anthropological applications, which often involve rare and fragile specimens. This study compares mineral density values calculated for a sample of bones scanned-at the same sites-in air and in water. The results indicate that, when scanned in air, the mineral density of trabecular bone is dramatically underestimated, while that of cortical bone is slightly overestimated. We present a linear regression equation to correct this error but recommend that, when possible, researchers calculate their own regressions based on their specific scanning conditions.

Extent and variation of omeprazole prescribing in an elderly population of Ontario

OBJECTIVE

To determine the extent of omeprazole prescribing in the senior population of Ontario over a 1-year period; the variation in omeprazole prescribing for this population according to age group, gender, and geographic region: and the extent of inappropriate prescribing of omeprazole for this population.

DESIGN

Retrospective drug utilization review of prescription drug insurance claims.

DATA SOURCE

The Ontario Drug Benefit (ODB) program claims database.

OUTCOME MEASURES

The following outcomes were measured: the proportion of seniors in Ontario who received a prescription for omeprazole from April 1, 1992 to March 31, 1993: effects of age group, gender, and geographic region of residence on omeprazole prescribing; and the extent of inappropriate omeprazole prescribing according to the ODB criteria for use. Prescribing of omeprazole was defined as inappropriate if a first-line antiulcer drug (i.e., histamine2-receptor antagonist) was not prescribed within 1-6 months of the first prescription claim for omeprazole.

RESULTS

A total of 29,936 seniors in Ontario received omeprazole from April 1, 1992 to March 31, 1993 (2.53 recipients per 100 eligible population). The age-gender group most frequently prescribed omeprazole was women 65-74 years, followed by women and men 75 years or older, and then men 65-74 years. Omeprazole prescribing varied widely among the 48 provincial counties (range of 1.66 recipients per 100 eligible population to 4.52 recipients per 100 population, p < 0.001). There was no evidence of a clustering effect in omeprazole prescribing at the county level. Prescribing of omeprazole was considered to be inappropriate for 80.5% of recipients.

CONCLUSIONS

This study demonstrated the ineffectiveness of the ODB limited-use program in controlling omeprazole prescribing. Further study should be done to examine determinants of variation in prescribing by geographic region.

Expression of the MRP and MDR1 multidrug resistance genes in small cell lung cancer

Acquired multidrug resistance is a major obstacle to a cure for small cell lung cancer (SCLC). Overexpression of the MDR1 gene occurs infrequently in multidrug-resistant SCLC cell lines. The multidrug resistance protein (MRP) can confer multidrug resistance, but its role in clinically acquired drug resistance is unknown. The purpose of this study was to measure expression of MRP and MDR1 mRNA in cell lines and clinical samples from SCLC patients and to correlate the results with drug sensitivity profiles. Twenty-three SCLC cell lines and 10 tumor samples from SCLC patients were examined. Samples expressing MRP and MDR1 were identified by reverse transcription-PCR, and levels of MRP mRNA in the cell lines were measured by quantitative reverse transcription-PCR. One of 23 cell lines (4%) expressed MDR1 mRNA, whereas MRP expression was detected in 19 of 23 cell lines (83%). There was a significant correlation between doxorubicin resistance and MRP expression levels (r = 0.422; P = 0.045). Of the 10 clinical samples, 3 expressed only MRP, 2 expressed only MDR1, and 4 expressed both drug resistance genes. In summary, MRP is frequently expressed in clinical samples and cell lines from SCLC patients, and the levels correlate with doxorubicin resistance in unselected SCLC cell lines. Expression of MDR1 can be detected in clinical samples of SCLC but is rarely found in cell lines from drug-resistant patients. These multidrug resistance proteins may contribute to the multifactorial problem of clinically acquired drug resistance in SCLC.