Biomedical subjects

N Dib

Publications and source records attributed to N Dib.

8 recordsLinked to original sources

PubMed2006

Angiogenic gene therapy in patients with nonrevascularizable ischemic heart disease: a phase 2 randomized, controlled trial of AdVEGF(121) (AdVEGF121) versus maximum medical treatment.

The demonstration that angiogenic growth factors can stimulate new blood vessel growth and restore perfusion in animal models of myocardial ischemia has led to the development of strategies designed for the local production of angiogenic growth factors in patients who are not candidates for conventional revascularization. The results of recent clinical trials of proangiogenesis gene therapy have been disappointing; however, significant limitations in experimental design, in particular in gene transfer strategies, preclude drawing definitive conclusions. In the REVASC study cardiac gene transfer was optimized by direct intramyocardial delivery of a replication-deficient adenovirus-containing vascular endothelial growth factor (AdVEGF121, 4 x 10(10) particle units (p.u.)). Sixty-seven patients with severe angina due to coronary artery disease and no conventional options for revascularization were randomized to AdVEGF121 gene transfer via mini-thoracotomy or continuation of maximal medical treatment. Exercise time to 1 mm ST-segment depression, the predefined primary end-point analysis, was significantly increased in the AdVEGF121 group compared to control at 26 weeks (P=0.026), but not at 12 weeks. As well, total exercise duration and time to moderate angina at weeks 12 and 26, and in angina symptoms as measured by the Canadian Cardiovascular Society Angina Class and Seattle Angina Questionnaire were all improved by VEGF gene transfer (all P-values at 12 and 26 weeks < or =0.001). However, if anything the results of nuclear perfusion imaging favored the control group, although the AdVEGF121 group achieved higher workloads. Overall there was no significant difference in adverse events between the two groups, despite the fact that procedure-related events were seen only in the thoracotomy group. Therefore, administration of AdVEGF121 by direct intramyocardial injections resulted in objective improvement in exercise-induced ischemia in patients with refractory ischemic heart disease.

Adenoviridae↗

PubMed2006

Chronic ischemic gastritis: case report of a difficult diagnosis and review of the literature.

Chronic ischemic gastritis is an unusual entity that is rarely distinguished from other forms of intestinal ischemia. On the basis of a case encountered and a subsequent review of the literature, the main features of this rare condition are described here. A better understanding and awareness of the disease should improve the diagnosis and ultimately also the prognosis.

Chronic Disease↗

PubMed2001

Fractional flow reserve compared with intravascular ultrasound guidance for optimizing stent deployment.

BACKGROUND: Determination of fractional flow reserve (FFR) has been proposed as a means to assess stent deployment. In this prospective, multicenter trial, we evaluate the use of FFR to optimize stenting by comparing it with standard intravascular ultrasound (IVUS) criteria. METHODS AND RESULTS: Eighty-four stable patients with isolated coronary lesions underwent coronary stent deployment starting at 10 atm and increased serially by 2 atm until the FFR was >/=0.94 or 16 atm was achieved. IVUS was then performed. FFR was measured with a coronary pressure wire with intracoronary adenosine to induce hyperemia. The diagnostic characteristics of an FFR <0.94 to predict suboptimal stent expansion by IVUS, defined in both absolute and relative terms, were calculated. Over a range of IVUS criteria, the highest sensitivity, specificity, and predictive accuracy of FFR were 80%, 30%, and 42%, respectively. Receiver operator characteristic analysis defined an optimal FFR cut point at >/=0.96; at this threshold, the sensitivity, specificity, and predictive accuracy of FFR were 75%, 58%, and 62%, respectively (P=0.03 for comparison of predictive accuracy, P=0.01 for concordance between FFR and IVUS). The negative predictive value was 88%. Significantly better diagnostic performance was achieved in a subgroup that received higher doses (>30 microgram) of intracoronary adenosine during pressure measurements, suggesting that FFR might be overestimated in the other group. CONCLUSIONS: A fractional flow reserve <0.96, measured after stent deployment, predicts a suboptimal result based on validated intravascular ultrasound criteria; however, an FFR >/=0.96 does not reliably predict an optimal stent result. Higher doses of intracoronary adenosine than previously used to measure FFR improve these results.

Adenosine↗

PubMed2001

Urgent coronary bypass surgery for failed percutaneous coronary intervention in the stent era: Is backup still necessary?

BACKGROUND: Current practice guidelines for performance of percutaneous coronary intervention (PCI) in the United States mandate availability of on-site surgical backup. With the decreasing frequency of urgent coronary bypass surgery (UCABG) with newer technologies, it is unclear whether such backup continues to be necessary. METHODS: A database of 5655 consecutive patients undergoing PCI at a single center between August 1, 1992, and December 31, 1997, was analyzed. Outcomes were determined as well as clinical, lesion, and procedural characteristics of patients during 4 time periods preceding and during use of coronary stenting. RESULTS: Frequency of UCABG for failed PCI decreased from 2.2% to 0.6% in the most recent time period (P <.01) with no change in incidence of in-hospital death or myocardial infarction. Incidence of stenting progressively increased to 72% in the latest period. Patients requiring UCABG had a higher prevalence of acute coronary syndromes (95%) and type B lesions (79%), but these characteristics were also common in patients who did not undergo UCABG. Although coronary stents were available during the last 3 periods studied, only 30% of UCABG patients had lesions or complications amenable to stenting, and stenting attempts in these patients were all unsuccessful. Despite stenting and use of perfusion balloons and intra-aortic balloon pumps, only 40% of patients having UCABG were stable and pain free on transfer to the operating room. CONCLUSIONS: Although use of UCABG for a failed PCI is currently very low, there are no satisfactory predictors, patients requiring UCABG are frequently clinically unstable, and availability of stenting does not reliably eliminate the need for UCABG or result in a decrease in mortality. This small group of patients continues to require readily available surgical standby.

Angioplasty, Balloon, Coronary↗

PubMed2001

In vivo magnetic resonance imaging and surgical histopathology of intracardiac masses: distinct features of subacute thrombi.

We evaluated intracardiac masses in vivo, in situ and histologically to determine tissue properties revealed by magnetic resonance (MR) imaging. In 15 consecutive patients scheduled for cardiotomy, the cardiac chambers were studied preoperatively with MR imaging and echocardiography. Visual examination of one or more chambers was performed during cardiotomy for mitral valve replacement, aneurysmectomy, atrial septal repair and atriotomy. Six thrombi (1 atrial appendage, 5 ventricular) and 2 atrial myxomas were removed and subjected to histological analysis. All masses were detected preoperatively by MR imaging. The smallest was a subacute 3-mm mural clot in the left ventricle and was undetected by transesophageal and transthoracic echocardiography. The 3 subacute clots had homogeneously low MR signals, did not enhance with gadolinium and exhibited magnetic susceptibility effects; histopathology confirmed these clots to be avascular and laden with dense iron deposition related to hemoglobin breakdown products. The 3 organized clots had intermediate and heterogeneous MR signals and multiple areas of gadolinium enhancement. The 2 myxomas had low MR signals and gadolinium enhancement in the core and septal attachment; these areas had dense neovascular channels. Subacute thrombi appear to have MR features that are distinct from organized thrombi and myxomas, and MR images of subacute thrombi contrast sharply with normal cardiac structures, enabling detection of thin mural clots that may be echographically occult. These findings may be of value, because a subacute clot may be more likely than an organized thrombus to give rise to an embolus.

Aged↗

PubMed1998

Validation of Doppler FloWire for measurement of coronary flow reserve in humans.

Previous studies have validated the 133Xenon (133Xe) method to assess regional myocardial blood flow and coronary flow reserve (CFR). Doppler FloWire (DFW) has been used recently for measuring CFR to assess the physiological significance of coronary stenosis. Data obtained by DFW has never been correlated to 133Xe. Our study compared data from DFW measurement of CFR to that obtained by 133Xe in 31 consecutive patients with variable coronary stenosis. Regional myocardial blood flow was measured by assessing the rate constants of 133Xe washout using multicrystal gamma camera after injection (20 millicuries) in the right or left coronary artery. CFR was assessed by measuring resting and hyperemic coronary blood flow by 133Xe and DFW using i.v. adenosine (140 mcg/k/min x 3 min). CFR was also measured by DFW giving intracoronary (i.c.) adenosine (12 microg in the right coronary, 18 microg in the left). In both methods--133Xe and DFW--coronary flow reserve was defined as the ratio of maximal hyperemic-to-baseline flow. DFW and 133Xe assessment of CFR correlated highly, whether adenosine was used i.c.(r=0.87; P=0.0001) or i.v.(r=0.78; P=0.0001). CFR obtained by DFW following i.c. and i.v. adenosine correlated well (r=0.79; P=0.0001). i.c. adenosine has fewer side effects. Both DFW and 133Xe are comparable in measuring CFR in humans.

Aged↗

PubMed1998

Service-level agreements at the Huddersfield NHS Trust.

Service-level agreements (SLAs) have been claimed to be an excellent vehicle for organisational improvement where there is a substantial degree of departmental autonomy. Such a situation is likely to exist in NHS trust hospitals because of the differentiated nature of the work performed by each department, with varying degrees of specialisation and professionalism, access to patients, use of technology and differing cost bases but also an interdependence of the direct services to the support services. It is proposed that SLAs can be used to promote improved integration between departments, quality assurance and provide a framework for cost transfer charging. The article describes and analyses SLAs from an overview of the idea to the particular implementation to date at the Huddersfield NHS Trust. SLAs have been negotiated between the Directorate of Clinical Support and its customers, and these are supported by computerised measurement and reporting tools.

Ancillary Services, Hospital↗

PubMed1996

Amniotic fluid embolism causing severe left ventricular dysfunction and death: case report and review of the literature.

Hemodynamic instability in amniotic fluid embolism has previously been demonstrated only by right heart catheterization. We present detailed documentation obtained by echocardiography and cardiac catheterization of a 35-year-old woman who developed amniotic fluid embolism and died from severe left ventricular dysfunction and wide QRS complex tachycardia despite intensive medical therapy (inotropes) and mechanical (intraaortic balloon pump) support.

Abortion, Therapeutic↗