Nikolaos Karkavitsas

Myocardial perfusion in patients with permanent ventricular pacing and normal coronary arteries

OBJECTIVES The purposes of this study were to test the specificity of dipyridamole myocardial perfusion scintigraphy in patients with permanent ventricular pacing (PVP) and to evaluate coronary blood flow and reserve in these patients. BACKGROUND Permanent ventricular pacing is associated with exercise perfusion defects on myocardial scintigraphy in the absence of coronary artery disease (CAD). On the basis of studies in patients with left bundle brunch block, coronary vasodilation with dipyridamole has been proposed as an alternative to exercise testing for detecting CAD in paced patients, but this approach has never been tested. METHODS Fourteen patients with a PVP and normal coronary arteries underwent stress thallium-201 scintigraphy and cardiac catheterization. In these patients and in eight control subjects, coronary flow velocities were measured in the left anterior descending coronary artery (LAD) and in the dominant coronary artery before and after adenosine administration. RESULTS In the paced patients, coronary flow velocities in the LAD and in the dominant coronary artery were significantly lower than those in the control subjects. In addition, seven patients showed perfusion defects on dipyridamole thallium-201 single-photon emission computed tomography, with a specificity of 50% for this test. The defect-related artery in these patients had lower coronary flow reserve (2.6 +/- 0.5) as compared with those without perfusion defects (3.9 +/- 1.0, p < 0.05) or the control group (3.5 +/- 0.5, p < 0.05). CONCLUSIONS Permanent ventricular pacing is associated with alterations in regional myocardial perfusion. Furthermore, abnormalities of microvascular flow, as indicated by reduced coronary flow reserve in the defect-related artery, are at least partially responsible for the uncertain specificity of dipyridamole myocardial perfusion scintigraphy.

The predictive role of serum and bronchoalveolar lavage cytokines and adhesion molecules for acute respiratory distress syndrome development and outcome

BackgroundThe predictive role of many cytokines and adhesion molecules has not been studied systematically in acute respiratory distress syndrome (ARDS).MethodsWe measured prospectively tumour necrosis factor alpha (TNF-α), interleukin (IL)-1, soluble vascular adhesion molecule-1 (VCAM-1) and soluble intercellular adhesion molecule-1 (ICAM-1) in serum and bronchoalveolar lavage fluid (BALF) within 2 hours following admission, in 65 patients. The patients were divided into: those fulfilling the criteria for ARDS (n = 23, group A), those who were pre-ARDS and who developed ARDS within 24 hours (n = 14, group B), and those on pre-ARDS but who never developed ARDS (n = 28, group C).ResultsAll the measured molecules were only found at higher levels in the serum of patients that died either with or without ARDS (P < 0.05 – P < 0.0001). Patients at risk exhibited a good negative predictive value (NPV) of the measured molecules for ARDS development both in their serum (89 to 95%) and BALF (86 to 92%) levels. In contrast to BALF, serum levels of IL-1 and adhesion molecules exhibited a good NPV (68 to 96%), sensitivity (60 to 88%) and survival specificity (74 to 96%) in all groups. All molecules in serum and BALF IL-1 were correlated with the APACHE II (P < 0.05 – P < 0.0001). Serum and BALF IL-1 as well as BALF TNF-α were negatively correlated to PaO2/FiO2 (all P < 0.05).ConclusionsThe studied molecules have good NPV for ARDS development both in serum and BALF. Serum rather than BALF levels seem to be related to outcome.

Prognostic Value of Serum Tumor Markers in Patients with Lung Cancer

Background: The role of tumor markers in the diagnosis and prognosis of lung cancer is under investigation. Objectives: The aim of this study was to investigate the diagnostic and prognostic significance of pre-therapeutic levels of various serum tumor markers, CYFRA 21-1, neuron-specific enolase (NSE), tissue polypeptide antigen (TPA), carcinoembryonic antigen (CEA), CA 125 and squamous cell carcinoma antigen (SCCAg), in patients with lung cancer. Methods: We studied 102 consecutive patients (mean age 65.2 ± 11 years) with newly diagnosed lung cancer (96 males, 94%, with a mean age of 66.3 ± 10.5 years). All patients had a 5-year follow-up. Measurements of the serum tumor markers were performed on initial diagnosis. Results: Eighty-four patients (82%) had non-small-cell lung cancer (NSCLC) and 18 (18%) small-cell lung cancer (SCLC). From the 84 patients with NSCLC, 34 patients (33%) had squamous-cell lung cancer, 23 (22%) adenocarcinoma and 23 (22%) large-cell carcinomas. The overall median survival was 8.5 months. All SCLC patients had extensive disease with a median survival of 10.1 months and NSCLC patients of 8.4 months. Significant differences in the mean values of NSE and CYFRA 21-1 were observed between SCLC and NSCLC. In NSCLC, CYFRA 21-1, TPA, CA 125 and SCCAg serum levels were related to the stage of the disease at diagnosis, and CYFRA 21-1, NSE, TPA and CA-125 were related to a poor outcome. None of the above tumor markers was related to survival in the SCLC group. Conclusion: CYFRA 21-1 and NSE may help to differentiate cell types in lung cancer patients. Also, CYFRA 21-1 with TPA and CA 125 may provide useful information regarding the staging of the disease at diagnosis and the prognosis of patients with NSCLC.

Phasic coronary flow pattern and flow reserve in patients with left bundle branch block and normal coronary arteries.

OBJECTIVES The purpose of this study was to determine whether scintigraphic myocardial perfusion defects in patients with left bundle branch block (LBBB) and normal coronary arteries are related to abnormalities in coronary flow velocity pattern and/or coronary flow reserve. BACKGROUND Septal or anteroseptal defects on exercise myocardial perfusion scintigraphy are common in patients with LBBB and normal coronary arteries. METHODS Thirteen patients (7 men, age 61+/-8 years) with LBBB and normal coronary arteries underwent stress thallium-201 scintigraphy and cardiac catheterization. In all patients and in 11 control subjects coronary blood flow parameters were calculated from Doppler measurements of flow velocity in the left anterior descending coronary artery (LAD) before and after adenosine administration. RESULTS The time to maximum peak diastolic flow velocity was significantly longer both for the seven patients with (134+/-19 ms) and for the six without (136+/-7 ms) exercise perfusion defects than for controls (105+/-12 ms, p < 0.05), whereas the acceleration was slower (170+/-54, 186+/-42 and 279+/-96 cm/s2, respectively, p < 0.05). Coronary flow reserve in the patients with exercise perfusion defects (2.7+/-0.3) was significantly lower than in those without (3.7+/-0.5, p < 0.05) or in the control group (3.4+/-0.5, p < 0.05). CONCLUSIONS Patients with LBBB have an impairment of early diastolic blood flow in the LAD due to an increase in early diastolic compressive resistance resulting from delayed ventricular relaxation. Furthermore, exercise scintigraphic perfusion defects in these patients are associated with a reduced coronary flow reserve, indicating abnormalities of microvascular function in the same vascular territory.

Urine Interleukin-8 as a Marker of Vesicoureteral Reflux in Infants

OBJECTIVE. Vesicoureteral reflux (VUR) is a common finding in children presenting with urinary tract infection (UTI) and prenatally diagnosed urinary tract dilatation and in relatives of index patients. Children with VUR are at risk for ongoing renal damage with subsequent infections. Detecting VUR and renal scarring currently depends on imaging modalities with associated problems of radiation, invasiveness, and expense. Noninvasive methods would greatly facilitate diagnosis and would also help in identifying relatives of index cases who should be screened. Interleukin-8 (IL-8) is produced by epithelial cells of the renal tract in response to inflammatory stimuli and has been shown to increase during acute UTI. The objective of this study was to assess the urine levels of IL-8 as a noninvasive marker of VUR in infants in the absence of a recent UTI episode. METHODS. We evaluated urine concentrations of IL-8 in 59 infants aged 1 month to 2 years. All infants were free of UTI for a minimum of 3 weeks before IL-8 evaluation. Infants were divided into 3 groups: group A, subjects with proven VUR (24 infants aged 0.15–1.95 years, median 0.43); group B, subjects with a history of UTI but negative investigation for VUR (14 infants aged 0.32–1.95 years, median 0.57); and group C, subjects without any history of acute or chronic condition that might impair renal function (21 infants aged 0.08–1.92 years, median 0.33). IL-8 concentrations were determined by a commercially available quantitative enzyme-linked immunosorbent assay. To avoid dilution effects, urinary levels of IL-8 were expressed as the ratio of cytokine-to-urinary creatinine. RESULTS. Results were presented as medians and ranges. The Kruskal-Wallis test, the Mann-Whitney rank sum U test, and the Spearman rank order correlation test were performed for the univariate analysis. Two-tailed P values were calculated and the conventional level of significance P < .05 was applied in all cases. Infants in groups A and B had been free of UTI for a period of 3 to 52 weeks (median, 5.0 weeks) and 3 to 78 weeks (median, 4.5 weeks), respectively, before IL-8 determination. No significant difference was noted in the length of the UTI-free period between groups A and B (P = .469). Urine creatinine concentrations did not differ among groups A, B, and C (medians 1.15, 2.25, and 1.15 μmol/mL, respectively; P = .080). The median urine IL-8/creatinine concentrations (pg/μmol) were 40.5 (range, 2.04–3874) in group A, 1.91 (range, 0.001–386) in group B, and 2.47 (range, 0.002–55.6) in group C. Urine IL-8/creatinine concentrations were significantly higher in group A than both in group B (P = .0003) and in group C (P < .0001). No significant difference was observed between groups B and C (P = .749). In group A, no significant correlation was shown between IL-8/creatinine concentrations and the presence of renal parenchymal damage (P = .506), reflux grade (P = .770), or time from UTI (P = .155). A receiver-operator characteristic curve was constructed by plotting the sensitivity versus the specificity for different cutoff concentrations of IL-8/creatinine. With a cutoff concentration of urinary IL-8/creatinine at 5 pg/μmol, the sensitivity of this marker in diagnosing VUR was 88%, the specificity 69%, the positive prognostic value 66%, and the negative prognostic value 89%. In higher cutoff concentrations, specificity of the marker increased but sensitivity rapidly decreased. CONCLUSIONS. We present evidence that urine IL-8 concentrations remain elevated in infants with VUR even in the absence of UTI and that a cutoff of 5 pg/μmol IL-8/creatinine is of high sensitivity and adequate specificity for diagnosing VUR. Elevated urine IL-8 levels in VUR and renal scarring have already been reported; however, the present study is, to our knowledge, the first to confirm significant differences between infants with VUR and infants with a history of UTI alone and healthy controls, and to suggest a reliable cutoff concentration for diagnosing VUR. Our findings additionally suggest that inflammatory process in VUR is ongoing even after UTI has resolved, pointing against the currently held belief that sterile reflux cannot harm kidneys. The chronic inflammatory cell infiltrate associated with reflux nephropathy rather than VUR itself might offer an explanation for the secretion of IL-8, which may well be independent of reflux grade. Using urine IL-8 for diagnosing VUR is not free of limitations, because IL-8 may be elevated as a result of urinary tract manipulation or undetected UTI. In addition, this study focused on infants and not in older children with longstanding VUR. Increased urine IL-8 concentrations after UTI has resolved is a promising noninvasive marker for an initial screening for VUR in infancy with high sensitivity and adequate specificity.

Abnormal heart rate recovery immediately after treadmill testing: Correlation with clinical, exercise testing, and myocardial perfusion parameters

BackgroundThe increase in heart rate during exercise is considered to be attributed to sympathetic system activation combined with parasympathetic withdrawal. The prognostic importance of the chronotropic response to exercise and heart rate recovery 1 minute after exercise has already been established. The purpose of this study was to evaluate heart rate recovery as an index of myocardial ischemia, by correlating heart rate recovery with known parameters of myocardial ischemia.>/<Methods and ResultsIncluded in the study were 304 consecutive patients (73% men), aged 34 to 82 years. Patients whose heart rate recovery value or myocardial perfusion imaging could have been influenced by factors other than ischemic disease were excluded from the study. The patients underwent single photon emission computed tomography myocardial perfusion imaging combined with symptom-limited exercise testing with thallium 201 or technetium 99m tetrofosmin. The value for heart rate recovery was defined as the decrease in heart rate from peak exercise to 1 minute after termination of exercise. For semiquantitation of the scintigram, the uptake of the radiotracer was graded on a scale from 0 to 4. Twenty-one beats per minute was defined as the lowest normal value for heart rate recovery. We found 74 patients (24%) with an abnormal value. We also found a significant correlation between heart rate recovery 1 minute after exercise and stress myocardial perfusion score. In addition, there was a statistically significant relationship between heart rate recovery and chronotropic variables. Patients with an abnormal value of heart rate recovery were generally of an older age, were more likely men, had a higher frequency of risk factors for coronary artery disease, were mostly taking cardioactive medications, had lower efficiency during treadmill testing, and had more pathologic findings on the scintigram.>/<ConclusionsMyocardial ischemia, as assessed by myocardial perfusion imaging, is an important correlate of heart rate recovery. There is a significant correlation between chronotropic variables during exercise testing and heart rate recovery 1 minute after exercise. It seems that the heart rate recovery value 1 minute after peak exercise may be considered a reliable index of the severity of myocardial ischemia.>/<

The clinical significance of serum and bronchoalveolar lavage inflammatory cytokines in patients at risk for Acute Respiratory Distress Syndrome

BackgroundThe predictive role of many cytokines has not been well defined in Acute Respiratory Distress Syndrome (ARDS).MethodsWe measured prospectively IL-4, IL-6, IL-6 receptor, IL-8, and IL-10, in the serum and bronchoalveolar lavage fluid (BALF) in 59 patients who were admitted to ICU in order to identify predictive factors for the course and outcome of ARDS. The patients were divided into three groups: those fulfilling the criteria for ARDS (n = 20, group A), those at risk for ARDS and developed ARDS within 48 hours (n = 12, group B), and those at risk for ARDS but never developed ARDS (n = 27, group C).ResultsAn excellent negative predictive value for ARDS development was found for IL-6 in BALF and serum (100% and 95%, respectively). IL-8 in BALF and IL-8 and IL-10 serum levels were higher in non-survivors in all studied groups, and were associated with a high negative predictive value. A significant correlation was found between IL-8 and APACHE score (r = 0.60, p < 0.0001). Similarly, IL-6 and IL-6r were highly correlated with PaO2/FiO2 (r = -0.27, p < 0.05 and r = -0.55, p < 0.0001, respectively).ConclusionsBALF and serum levels of the studied cytokines on admission may provide valuable information for ARDS development in patients at risk, and outcome in patients either in ARDS or in at risk for ARDS.

Effects of tumor necrosis factor alpha inhibition with infliximab on lipid levels and insulin resistance in patients with inflammatory bowel disease.

Introduction TNF-&agr; is a critical mediator of inflammation with an important role in metabolic profile and insulin resistance. The regulation of these parameters by TNF-&agr; in inflammatory bowel disease (IBD) is, however, poorly understood. The aim of this study was to assess the in-vivo TNF-&agr;-mediated regulation of insulin resistance and of lipid levels in patients with IBD. Methods Twenty-two patients with IBD (eight females; 19 Crohns disease) received infliximab according to treating physicians assessment at weeks 0, 2 and 6 from baseline and subsequently every 8 weeks and were prospectively followed for 14 weeks. Fasting insulin, total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, apolipoprotein A1 (apo-A1), apolipoprotein B100 and lipoprotein a were measured in serum at baseline and at week 14. Insulin resistance was calculated with the use of the Homeostasis Model Assessment index. Results Infliximab therapy induced clinical response or remission in 19 of the 22 patients. C-reactive protein levels were significantly decreased by week 14. Body mass index was increased in all patients. No difference was observed in insulin levels, Homeostasis Model Assessment index, triglycerides, LDL cholesterol, apolipoprotein B100 and lipoprotein a. In contrast, total cholesterol, HDL cholesterol and apo-A1 levels were significantly increased from baseline. Conclusion TNF-&agr; inhibition does not alter insulin resistance in IBD patients. In contrast, total cholesterol, HDL cholesterol and apo-A1 levels are significantly increased after infliximab treatment compared with baseline. The importance of these alterations needs to be clarified in future studies.

Value of Tc-99m sestamibi scintigraphy in the detection of bone lesions in multiple myeloma: comparison with Tc-99m methylene diphosphonate

Abstract. Technetium 99m-2-methoxyisobutylisonitrile (Tc-99m MIBI) is a lipophilic agent that accumulates preferentially within living malignant cells due to the higher transmembrane electrical potential as a consequence of the higher metabolic rate than in the surrounding normal cells. It has been effectively used to detect malignant tumors at diagnosis and follow-up and has been reported to be useful in detecting disease lesions in multiple myeloma. We studied 28 consecutive patients with multiple myeloma at diagnosis to determine the value of Tc-99m MIBI in comparison with Tc-99m methylene diphosphonate (MDP), conventional X-rays, computed tomography (CT) scan, and magnetic resonance imaging (MRI). We found 26 patients with obvious osteolytic lesions in X-rays, 22 patients with positive Tc-99m MIBI scans, and 15 patients with positive Tc-99m MDP scans. There was no coincidence of the positive lesions in the two scans, while in two patients the osteolytic areas were positive in the Tc-99m MDP scans, and in one case the osteolytic area was positive in the Tc-99m MIBI scan. The intensity of Tc-99m MIBI scans correlated with disease activity as determined by lactate dehydrogenase (LDH) (p<0.05), C-reactive protein (CRP) (p<0.01), β2-microglobulin (p<0.05), and serum ferritin (p<0.01). We believe that Tc-99m MIBI scintigraphy can detect bone marrow lesions in myeloma patients that cannot be detected by other imaging methods and that it can be useful especially in solitary myeloma to exclude other involved sites. In addition, it could be a prognostic factor related to disease activity and multidrug resistance. We believe that a multicenter study is needed to evaluate the usefulness of this agent.

High concentrations of the CA-125, CA 19-9 and CA 15-3 in the peritoneal fluid between patients with and without endometriosis

ObjectiveIn the present study we compared the levels of CA-125, CA 19-9, and CA 15-3 in the peritoneal fluid (PF) of patients with and without endometriosis, then assessed the possibility of a correlation among these tumor markers.Study designOur study was a controlled clinical study of patients undergoing laparoscopy for infertility or other benign gynecology conditions. Peritoneal fluid samples were collected from 65 women with endometriosis and 43 women without pelvic disease. Levels of CA-125, CA 19-9 and CA 15-3 in the peritoneal fluid were determined by immunoradiometric assay.ResultsThe concentration of CA-125 in PF from patients with endometriosis was significantly higher than that in the control group (p<0.001); for CA 19-9 and CA 15-3, PF concentrations were not statistically different between these two groups. Women with endometriosis had significantly higher levels of CA-125 in proliferative and secretory phases than the control group (p<0.001 and p<0.002 respectively); furthermore, in patients with endometriosis the CA 19-9 levels were significantly lower in secretory phase than the proliferative (p<0.004). The levels of CA-125 were significantly lower in women with tubal ligation, in comparison with infertility or pelvic pain in the control group (p<0.001). No significant difference was seen in women with infertility or pelvic pain in endometriosis group and the levels of CA-125, CA 19-9, and CA 15-3. We did not find any correlation between the stages of endometriosis and the concentration of CA-125, CA 19-9 and CA 15-3. A significant correlation between the CA 19-9 levels and CA 15-3 in patients with endometriosis was found (r=0.72, p=0.001).ConclusionsWe found high concentrations of CA-125, CA 19-9, and CA 15-3 in the peritoneal fluid of women with and without endometriosis in the Yale series. However, the levels only of CA-125 were higher in women with endometriosis, but without diagnostic value. The role of simultaneously high concentrations of CA 19-9 and CA 15-3 in women with endometriosis needs to be explored further.