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Biomedical subjects

Atif Zaman

Publications and source records attributed to Atif Zaman.

17 recordsLinked to original sources
PubMed2007

Endoscopic screening for varices in cirrhotic patients: data from a national endoscopic database.

BACKGROUND: The current guidelines for primary prophylaxis of variceal hemorrhage in cirrhotic patients recommend screening for varices with upper endoscopy (EGD). Utilization and outcomes of screening in clinical practice are unknown. OBJECTIVE: Our purpose was to determine the use of endoscopic variceal screening in diverse practice settings and to determine factors associated with the finding of esophageal varices. DESIGN: Endoscopic reports generated by the Clinical Outcomes Research Initiative (CORI) repository were analyzed to determine the use, changes over time, and findings of screening upper endoscopies between January 1, 2000, and December 31, 2003. SETTING: Data from 68 CORI practices (70% community/17% academic/13% Veterans Affairs Medical Center [VAMC]) were evaluated. PATIENTS: A total of 1688 of 172,854 EGDs were performed for the purpose of screening for varices. RESULTS: Overall, there was a linear increase in annual proportion of screening EGDs performed (P < .0001). A significantly greater proportion of variceal screening EGDs are performed in academic centers compared with VAMC and community practices. Varices were found in 881 screened patients (52.2%). Varices were found more often in Child-Pugh class B/C (71.9%) compared with Child-Pugh class A (42.7%) patients. Of those with varices found, patients with Child-Pugh class B/C were more likely to have large varices than were patients with Child-Pugh class A (P = .02). LIMITATIONS: A limitation of this study was the inability to determine the total number of cirrhotic patients cared for at each CORI site included in this study. CONCLUSIONS: Endoscopic screening for varices represents a small proportion of all upper endoscopies performed. This proportion increased between 2000 and 2003. Varices were found more frequently in patients with more severe liver disease.

Adult↗
PubMed2006

Platelet count/spleen diameter ratio for the noninvasive diagnosis of esophageal varices: results of a multicenter, prospective, validation study.

BACKGROUND AND AIMS: Noninvasive assessment of esophageal varices (EV) may improve the management of patients with cirrhosis and decrease both the medical and financial burden related to screening. In this multicenter, international study, our aim was to prospectively validate the use of the platelet count/spleen diameter ratio for the noninvasive diagnosis of EV. METHODS: A total of 218 cirrhotic patients underwent screening endoscopy for EV. Platelet count/spleen diameter ratio ((N/mm3)/mm) was assessed in all patients and its diagnostic accuracy was calculated. On the basis of previous results, a platelet count/spleen diameter ratio cutoff of 909 was applied to this population. The diagnostic accuracy of the platelet count/spleen diameter ratio was further evaluated for both severity and etiology of disease subgroups. RESULTS: Prevalence of EV was 54.1%. The platelet count/spleen diameter ratio had 86.0% (95% CI, 80.7-90.4%) diagnostic accuracy for EV, which was significantly greater as compared with either accuracy of platelet count alone (83.6%, 95% CI 78.0-88.3%, P= 0.038) or spleen diameter alone (80.2%, 95% CI 74.3-85.3%, P= 0.018). The 909 cutoff had 91.5% sensitivity (95% CI 85.0-95.9%), 67.0% specificity (95% CI 56.9-76.1%), 76.6% positive predictive value, 87.0% negative predictive value, 2.77 positive likelihood ratio, and 0.13 negative likelihood ratio for the diagnosis of EV. Accuracy of the platelet count/spleen diameter ratio was maintained for both severity and etiology of disease subgroups. CONCLUSIONS: The platelet count/spleen diameter ratio may be proposed as a safe and reproducible means to improve the management of cirrhotic patients who should undergo screening endoscopy for EV.

Adult↗
PubMed2006

Alpha-fetoprotein and prognosis in acute liver failure.

Serum concentrations of alpha-fetoprotein (AFP), variably elevated during liver injury, have been suggested to be of prognostic importance in acute liver failure (ALF), higher values being associated with improved outcome. Using a nephelometric assay, we measured AFP in sera obtained on admission from 206 patients prospectively enrolled in the US ALF Study, and on day 3 in 162 of these patients. The AFP ratio was defined as the day 3 AFP concentration divided by that observed on day 1. Median (range) admission serum AFP in all patients was 8.1 (1-1,811) ng/mL and increased to 17.6 (1.1-1,162) ng/mL on day 3 (P < 0.001). Higher absolute levels were not associated with improved outcome. In fact, admission AFP levels were lower in survivors not receiving transplants than in those who died or were transplanted (P < 0.001), whereas there was no difference between the 2 groups on day 3 (P = 0.34). However, a rise in AFP values between day 1 and day 3 indicated a better prognosis: the AFP ratio was 2.2 (0.11-22.1) in spontaneous survivors and 0.87 (0.11-16.4) in nonsurvivors (P < 0.001). An increasing AFP level indicated by an AFP ratio >or=1 was observed in 70 of 98 (71%) survivors, whereas a ratio <1 was observed in 51 of 64 (80%) nonsurvivors. In conclusion, AFP values change dynamically during ALF. In this large prospective study, higher absolute values of AFP did not predict a favorable outcome, but a rising level of AFP over the first 3 hospital days frequently indicated survival.

Adolescent↗
PubMed2006

Portal hypertension-related bleeding: management of difficult cases.

Many advances have occurred in the management of varices over the years. Guidelines based on sound evidence have been developed to manage the esophageal variceal hemorrhage. Less is known about how best to manage some of the more difficult cases of bleeding related to portal hypertension. This article reviews evidence in the hypertensive gastropathy, ectopic varices, and management of patients who are intolerant of or have not responded to beta-blocker therapy. The goal of this article is to review the sparse available evidence and to suggest reasonable management options.

Dilatation, Pathologic↗
PubMed2006

A simple approach to noninvasively identifying significant fibrosis in chronic hepatitis C patients in clinical practice.

BACKGROUND: Identification of the presence of significant fibrosis is an important part of the diagnostic work-up of patients with chronic hepatitis C (CHC). AIM: To evaluate the performance of the aspartate to alanine aminotransferase ratio (AST/ALT ratio) and platelet count in reducing the number of liver biopsies and diagnosing the presence/absence of significant fibrosis in a large cohort of patients with CHC seen at 2 tertiary referral centers. METHODS: Liver biopsies of 409 patients with CHC were evaluated. Staging was carried out by means of the Ishak and METAVIR scores in the Italian and US series, respectively. Prevalence of significant fibrosis was 43%. Receiver operating characteristic curves were used to identify AST/ALT ratio and platelet count cutoffs with the highest accuracy for the diagnosis of significant fibrosis. These cutoffs were used to devise a diagnostic algorithm for reducing the number of liver biopsies and diagnosing/ruling out significant fibrosis. RESULTS: AST/ALT ratios increased and platelet counts decreased as liver fibrosis worsened. Both AST/ALT ratio (c-index=0.747) and platelet count (c-index=0.733) had high accuracy for the diagnosis of significant fibrosis. The use of AST/ALT ratio and platelet count cutoffs in a diagnostic algorithm would have avoided liver biopsy in 68.9% of the patients and would have correctly identified the absence/presence of significant fibrosis in 80.5% of these cases. CONCLUSIONS: In clinical practice, the use of simple, reproducible, and inexpensive parameters such as the AST/ALT ratio and platelet count can reduce the need for liver biopsy in a substantial proportion of patients with CHC.

Adult↗
PubMed2005

Bleeding caused by portal hypertension.

Variceal bleeding is one of the dreaded complications of portal hypertension. Patients who have suspected or proven cirrhosis should undergo diagnostic upper endoscopy to detect medium and large gastro-esophageal varices. Patients with medium and large gastro-esophageal varices should be treated with non-selective beta-blockers (propranolol or nadolol), and these agents should be titrated to a heart rate of 55 beats per minute or adverse effects. If there are contraindications to or if patients are intolerant to beta-blockers, it is appropriate to consider prophylactic banding therapy for individuals with medium-to-large esophageal varices. When patients who have cirrhosis present with GI bleeding, they should be resuscitated and receive octreotide or other vasoactive agents. Endoscopy should be performed promptly to diagnose the source of bleeding and to provide endoscopic therapy (preferably banding). The currently available treatment for acute variceal bleeding provides hemostasis in most patients. These patients, however, are at significant risk for rebleeding unless secondary prophylaxis is provided. Although various pharmacological, endoscopic, radiological, and surgical options are available, combined pharmacological and endoscopic therapy is the most common form of secondary prophylaxis. TIPS is a radiologically placed portasystemic shunt, and if placed in suitable patients, it can provide effective treatment for patients with variceal bleeding that is refractory to medical and endoscopic therapy.

Algorithms↗
PubMed2004

Urgent vs. elective endoscopy for acute non-variceal upper-GI bleeding: an effectiveness study.

BACKGROUND: Urgent endoscopy in patients with acute upper-GI bleeding identifies many patients who may be safely treated without hospitalization. The aim of this multicenter trial was to determine whether urgent endoscopy effectively decreases health care resource utilization in a real-life setting where primary care providers determine the course of care. METHODS: Ninety-three outpatients with acute upper-GI bleeding were randomized to either urgent endoscopy (before hospitalization) or elective endoscopy after admission. The results of urgent endoscopy and a recommendation regarding patient disposition were provided to the attending physician. Medical outcomes and resource utilization were measured. RESULTS: The timing of endoscopy did not affect resource utilization or patient outcomes. Length of stay was similar (urgent endoscopy, OR 3.98 days: 95% CI[2.84, 5.11] vs. elective endoscopy, OR 3.26 days: 95% CI[2.32, 4.21], p=0.45). The mean number of days in an intensive care unit was the same (1.2 days). The urgent endoscopy group had more high-risk endoscopic lesions (15 vs. 9; p=0.031). Outpatient care was recommended for 19 patients (40%). Only 4 patients were discharged. CONCLUSIONS: Urgent endoscopy did not reduce hospitalization or resource utilization because the results of early endoscopy did not impact the decision by attending physicians regarding admission. For early (triage) endoscopy to impact resource utilization, the results of endoscopy must change subsequent patient care.

Acute Disease↗
PubMed2004

Cardiopulmonary consequences of transjugular intrahepatic portosystemic shunts: role of increased pulmonary artery pressure.

GOALS: To determine whether increased pulmonary artery pressure (PAP) following transjugular intrahepatic portosystemic shunting (TIPSS) results in short-term mortality or cardiorespiratory complications. BACKGROUND: TIPSS is frequently performed for complications of cirrhosis. PAP increases following TIPSS; however consequences of this phenomenon are unknown. STUDY: Demographics, disease severity and etiology were recorded among patients undergoing TIPSS. PAP before and following TIPSS were measured and the relationship between PAP before and after TIPSS, and subsequent cardiorespiratory complications and mortality was examined. RESULTS: Thirty-one patients were enrolled (mean age 53 years, 74% men, 55% Child-Pugh class C cirrhosis). TIPSS was performed for variceal bleeding in 84% of cases. Ten patients (32%) died 5-20 days following TIPSS. PAP increased significantly following TIPSS (mean 20.8 mm Hg pre-TIPSS (95% CI 18.2-23.4) to 26.9 mm Hg post-TIPSS (95% CI 24.2-29.6, P = 0.0016). Congestive heart failure developed in 4 patients (13%), sepsis in 4 (13%), and ARDS in 8 (26%). Increased PAP following TIPSS was not associated with early mortality (P = 0.13), CHF (P = 0.31), or ARDS (P = 0.43). ARDS was the only significant predictor of short-term mortality following TIPSS (OR 18.7, P = 0.02 (95% CI: 1.5-232). CONCLUSION: PAP increases after TIPSS and cardiorespiratory complications are common, yet unrelated to increased PAP. ARDS is independently associated with increased risk of mortality after TIPSS.

Adult↗
PubMed2004

Changing compliance to the American College of Gastroenterology guidelines for the management of variceal hemorrhage: a regional survey.

OBJECTIVES: In mid-1997 the American College of Gastroenterology (ACG) published guidelines for the management of varices. The aim of this study is to assess the change in regional practice patterns between early 1997 (preguidelines) and 2000 (postguidelines). METHODS: Gastroenterologists in Oregon and Southwestern Washington state were sent a self-reporting questionnaire regarding the management of varices in March 1997 (prior to the publication of the guidelines) and again in August 2000. RESULTS: Fifty-seven of 75 (76%) and 68 of 92 (74%) of the surveys were completed in 1997 and 2000, respectively. Fifty to 60% of the respondents saw between three and five cirrhotic patients per month. Significantly, more respondents followed the guidelines to screen and treat large varices to prevent initial variceal hemorrhage in 2000 than in 1997, 54% versus 18% (p < 0.005). Of the respondents who performed screening of EGDs, the majority treated large varices with beta-blocker therapy (93% in 1997 and 97% in 2000). All respondents used early endoscopy to treat variceal bleeding. Significantly, most of the respondents began pharmacologic therapy prior to endoscopy if active variceal hemorrhage was suspected (with most choosing octreotide) in 2000 than in 1997, 83% versus 56% (p < 0.005). The majority of the respondents pursued repeat endoscopic therapy after cessation of the initial variceal bleeding episode (96% in 1997 and 95% in 2000), and most performed surveillance EGD once the varices had been eradicated (72% in 1997 and 79% in 2000). CONCLUSIONS: After the publication of the ACG guidelines, significantly more gastroenterologists screened for varices to prevent initial variceal hemorrhage and significantly more used pharmacologic therapy prior to endoscopic treatment for variceal hemorrhage.

Esophageal and Gastric Varices↗
PubMed2004

Comparative analysis of outcome following liver transplantation in US veterans.

The purpose of this study was to evaluate whether there was a difference in mortality following orthotopic liver transplantation (OLT) in a US veteran (VA) population (n = 149) compared to a non-VA (university) population (n = 285) and what factors could explain this difference. Survival following OLT for 149 VA patients was compared with that of 285 university patients. By Kaplan-Meier survival analysis, VA patients had higher mortality than university patients with respective 1-year, 3-year, and 5-year survival of 82%, 75%, and 68% vs. 87%, 82%, and 78% (p = 0.006). Gender, etiology of end-stage liver disease (ESLD) and donor age (i.e. older than 34 years) also significantly influenced survival. However, when donor and recipient age, gender, model for end-stage liver disease (MELD) score, and etiology of liver disease were included with hospital status in a multivariate Cox proportional hazards model, the VA population did not have higher mortality. A final model to predict mortality following transplantation was derived for all 434 patients where individuals were assigned risk scores based on the equation R = 0.219 (gender) + 0.018 (donor age) + 0.032 (recipient age) + 0.021 (MELD), where recipient age, donor age, and MELD score are the respective continuous variables and gender = 1 (men) and 0 for women (c-statistic = 0.71).

Adult↗
PubMed2003

Current Management of Esophageal Varices.

Acute variceal hemorrhage is the most lethal complication of cirrhosis. The reported mortality rate from a first episode of variceal hemorrhage is 17% to 57%. Management of varices can be categorized into three phases: 1) prevention of initial bleeding, 2) management of acute bleeding, and 3) prevention of rebleeding. Modalities for treatment include pharmacologic, endoscopic, and shunt therapy. For the prevention of first variceal hemorrhage, cirrhotic patients should undergo endoscopy to identify patients with large varices. Priority for screening for varices should be given to patients with low platelet count, splenomegaly, and advanced cirrhosis. Once large varices are identified, patients should be started on beta-blocker therapy, which reduces the risk of bleeding by 50%. If pharmacologic therapy is not tolerated or contraindicated, endoscopic band ligation should be performed, and surveillance of varices should be performed every 6 months thereafter. Shunt procedures are not indicated due to their higher rates of complications compared with medical therapy. For the management of acute variceal hemorrhage, patients should be started on prophylactic intravenous antibiotics and intravenous octreotide. Endoscopy should be performed to diagnose and treat variceal hemorrhage. Band ligation appears to be as effective as sclerotherapy, but with less complications. If hemostasis is not achieved, balloon tamponade can be used as a bridge to definitive therapy, which in this case would be a transjugular intrahepatic portosystemic shunt (TIPS). If TIPS is unavailable, a surgical shunt is indicated. Once an episode of acute bleeding has been controlled, variceal eradication is best accomplished with repeat band ligation every 10 to 14 days until varices are obliterated. Prevention of recurrent bleeding can be achieved with beta-blocker therapy. The addition of isosorbide mononitrate further reduces recurrent bleeding. This combination pharmacologic therapy has been shown to be superior to sclerotherapy and may be superior to band ligation. However, side effects of combination pharmacologic therapy may limit its effectiveness. Band ligation is preferred to sclerotherapy when considering endoscopic therapy due to less complications and lower cost. Surgical shunts should be used for prevention of rebleeding in patients who do not tolerate or are noncompliant with medical therapy and who have relatively preserved liver function. TIPS should be reserved for patients who have poor liver function and who have failed medical therapy.

Journal Article↗
PubMed2003

Validation and refinement of survival models for liver retransplantation.

Orthotopic liver retransplantation (re-OLT) is highly controversial. The objectives of this study were to determine the validity of a recently developed United Network for Organ Sharing (UNOS) multivariate model using an independent cohort of patients undergoing re-OLT outside the United States, to determine whether incorporation of other variables that were incomplete in the UNOS registry would provide additional prognostic information, to develop new models combining data sets from both cohorts, and to evaluate the validity of the model for end-stage liver disease (MELD) in patients undergoing re-OLT. Two hundred eighty-one adult patients undergoing re-OLT (between 1986 and 1999) at 6 foreign transplant centers comprised the validation cohort. We found good agreement between actual survival and predicted survival in the validation cohort; 1-year patient survival rates in the low-, intermediate-, and high-risk groups (as assigned by the original UNOS model) were 72%, 68%, and 36%, respectively (P <.0001). In the patients for whom the international normalized ratio (INR) of prothrombin time was available, MELD correlated with outcome following re-OLT; the median MELD scores for patients surviving at least 90 days compared with those dying within 90 days were 20.75 versus 25.9, respectively (P =.004). Utilizing both patient cohorts (n = 979), a new model, based on recipient age, total serum bilirubin, creatinine, and interval to re-OLT, was constructed (whole model chi(2) = 105, P <.0001). Using the c-statistic with 30-day, 90-day, 1-year, and 3-year mortality as the end points, the area under the receiver operating characteristic (ROC) curves for 4 different models were compared. In conclusion, prospective validation and use of these models as adjuncts to clinical decision making in the management of patients being considered for re-OLT are warranted.

Adult↗
PubMed2003

Tumor necrosis factor-alpha promoter polymorphisms and the risk of rejection after liver transplantation: a case control analysis of 210 donor-recipient pairs.

After orthotopic liver transplantation (OLT), allograft rejection remains an important problem and is the major reason that immunosuppressive therapy must be administered. Tumor necrosis factor-alpha (TNF-alpha) is a proinflammatory mediator that is central to the immune response, and intragraft expression of this cytokine is increased during acute cellular rejection (ACR). Polymorphisms within the TNF promoter have been identified and correlated with alterations in production. The aims of this study were to determine if an individual patient's propensity to develop ACR is related to the presence of these genetic polymorphisms (either alone or in combination) within donor and recipient tissue and to determine if these polymorphisms affect patient survival after OLT. The study group consisted of 210 patients who underwent OLT between 1989 and 1999 with at least 6 months survival, including 42 cases who had evidence of acute cellular rejection (biopsy-proven, elevated enzymes, and response to increased immunosuppression) and were matched 4:1 to controls (n = 168) with similar age, gender, underlying liver disease, date of transplant, and baseline immunosuppression. The underlying liver diseases were hepatisis C virus (HCV)/alcohol (70), HCV alone (50), alcohol (30), primary biliary cirrhosis (15), primary sclerosing cholangitis (15), autoimmune hepatitis/cirrhosis (10), cryptogenic (15), and hepatitis B virus (HBV) (5). DNA was extracted from paraffin-embedded donor and recipient liver tissue (total 420 samples), amplified, and sequenced for TNF single-nucleotide polymorphisms (TNFA-308 A/G and TNFA-238 A/G). We found no differences between the TNF allelic distributions among donors without liver disease (presumably representative of a normal control population) and patients with end-stage liver disease undergoing OLT. Multivariate analysis revealed no association with TNF polymorphisms (within donor or recipient tissue) and rejection risk or patient survival after transplantation. In this large case control analysis of patients undergoing liver transplantation for diverse etiologies, TNF promoter polymorphisms were not independently associated with rejection or survival.

Adult↗
PubMed2002

Irritable bowel syndrome.

Irritable bowel syndrome (IBS) is one of the most common diagnoses made in the primary care setting and is responsible for up to 40% of referrals to gastroenterologists. Approximately 70% of persons who meet the diagnostic criteria for IBS do not seek health care, and the remaining account for 12% of visits to primary care providers. IBS is a functional bowel disordered comprising abdominal pain associated with defecation or a change in bowel habit with features of disordered defecation and distension in the absence of any demonstrable abnormality. The diagnosis is based on clinical findings and the exclusion of other disorders. New pharmaceutical agents are available to treat the underlying disorder; however, the treatment of IBS still involves a comprehensive, multicomponent approach that includes medical management of dominant symptoms, dietary modifications, and, possibly, psychotherapy.

Antidepressive Agents↗
PubMed2002

A randomized controlled trial in a training institution comparing a pediatric variable stiffness colonoscope, a pediatric colonoscope, and an adult colonoscope.

BACKGROUND: There are few comparative data on the efficacy of different colonoscopes. This study compared the efficacy of a new pediatric variable stiffness colonoscope with that of standard pediatric and adult colonoscopes in the performance of routine colonoscopy. METHODS: Three hundred sixty-three consecutive patients were randomized to undergo colonoscopy with a pediatric variable stiffness (n = 122), pediatric (n = 114), or adult colonoscope (n = 127). Primary outcomes recorded were minutes to the cecum and completeness of the examination. Secondary outcomes included patient tolerance, use of abdominal compression, and endoscopists' assessment of the difficulty of the procedure. RESULTS: Cecal intubation rates were not statistically different between the groups: variable stiffness (94.3%), pediatric (96.5%), and adult (89.8%) (p = 0.099). There was no significant difference in mean insertion time, patient tolerance, use of abdominal compression, or endoscopists' global assessment or examination difficulty between groups. Overall, the initial completion rate of 93% increased to 97% on switching to a different colonoscope. Colonoscopy was unsuccessful more often and was more time consuming in women who had undergone hysterectomy. CONCLUSION: The variable stiffness colonoscope performs well, but does not appear to offer any distinct advantage over standard pediatric or adult colonoscopes for routine colonoscopy. Further study may identify subgroups of patients that benefit from this new technology.

Adult↗
PubMed2002

Tumor necrosis factor genetic polymorphisms and response to antiviral therapy in patients with chronic hepatitis C.

OBJECTIVE: Hepatitis C virus (HCV) is the major causal agent of non-A, non-B hepatitis and the leading indication for liver transplantation worldwide. The emerging field of immunogenetics has confirmed the significant role of heritability in host immune responses to infectious pathogens. Both the major and non-major histocompatibility complex genes are increasingly identified as candidate genes hypothesized to influence the susceptibility to, or the course of, a particular disease. We hypothesized that polymorphisms within the major histocompatibility complex class III region that encode for tumor necrosis factors (TNF)-alpha and TNF-beta might be predictive of response to antiviral therapy in patients with chronic hepatitis C. METHODS: A total of 155 subjects, including 110 HCV-seropositive individuals undergoing antiviral therapy and 45 ethnically similar HCV-negative controls, were studied. The HCV-positive patients had undergone antiviral treatment with either interferon monotherapy (n = 73) or in combination with ribavirin (n = 37) and were categorized as either nonresponders, sustained responders, or relapsers. Sixty (55%) patients had genotype 1 (1a or 1b). Genomic DNA was extracted, followed by polymerase chain reaction amplification and sequencing for two promoter TNF-alpha variants (at positions -238 and -308), as well as restriction fragment length analysis for four polymorphic loci within the TNF-beta gene (NcoI, TNFc, aa13, aa26). RESULTS: Although there was a trend toward higher frequency of the A allele in the TNF 238 promoter among HCV-infected patients (12% vs 4%), there were no significant differences in the distribution of the genotypic polymorphisms between patients and controls. Patients with the TNF 238 A allele had higher pretreatment viral loads as compared with patients homozygous for the wild type allele (7.2 x 10(6) +/- 4.2 x 10(6) copies/ml vs 3.8 x 10(6) +/- 0.34 x 10(6) copies/ml, p = 0.03). However, there was no association between TNF genetic markers, including multiple haplotypic combinations, and response to therapy. In addition, there was no correlation with these polymorphic loci and histological severity of liver disease. CONCLUSIONS: Although previous work has suggested potential roles for TNF in the pathogenesis of HCV infection, we were unable to identify any link between TNF genetic polymorphisms and histological severity or response to antiviral therapy.

Adult↗