Causes of cardiovascular and noncardiovascular death in the ISCHEMIA trial

BACKGROUND

The International Study of Comparative Health Effectiveness with Medical and Invasive Approaches trial demonstrated no overall difference in the composite primary endpoint and the secondary endpoints of cardiovascular (CV) death/myocardial infarction or all-cause mortality between an initial invasive or conservative strategy among participants with chronic coronary disease and moderate or severe myocardial ischemia. Detailed cause-specific death analyses have not been reported.

METHODS

We compared overall and cause-specific death rates by treatment group using Cox models with adjustment for pre-specified baseline covariates. Cause of death was adjudicated by an independent Clinical Events Committee as CV, non-CV, and undetermined. We evaluated the association of risk factors and treatment strategy with cause of death.

RESULTS

Four-year cumulative incidence rates for CV death were similar between invasive and conservative strategies (2.6% vs 3.0%; hazard ratio [HR] 0.98; 95% CI [0.70-1.38]), but non-CV death rates were higher in the invasive strategy (3.3% vs 2.1%; HR 1.45 [1.00-2.09]). Overall, 13% of deaths were attributed to undetermined causes (38/289). Fewer undetermined deaths (0.6% vs 1.3%; HR 0.48 [0.24-0.95]) and more malignancy deaths (2.0% vs 0.8%; HR 2.11 [1.23-3.60]) occurred in the invasive strategy than in the conservative strategy.

CONCLUSIONS

In International Study of Comparative Health Effectiveness with Medical and Invasive Approaches, all-cause and CV death rates were similar between treatment strategies. The observation of fewer undetermined deaths and more malignancy deaths in the invasive strategy remains unexplained. These findings should be interpreted with caution in the context of prior studies and the overall trial results.

Outcomes With Intermediate Left Main Disease: Analysis From the ISCHEMIA Trial

BACKGROUND

Patients with significant (≥50%) left main disease (LMD) have a high risk of cardiovascular events, and guidelines recommend revascularization to improve survival. However, the impact of intermediate LMD (stenosis, 25%-49%) on outcomes is unclear.

METHODS

Randomized ISCHEMIA (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches) participants who underwent coronary computed tomography angiography at baseline were categorized into those with (25%-49%) and without (<25%) intermediate LMD. The primary outcome was a composite of cardiovascular mortality, myocardial infarction (MI), or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest. The primary quality of life outcome was the Seattle Angina Questionnaire summary score.

RESULTS

Among the 3699 participants who satisfied the inclusion criteria, 962 (26%) had intermediate LMD. Among invasive strategy participants with intermediate LMD on coronary computed tomography angiography, 49 (7.0%) had significant (≥50% stenosis) left main stenosis on invasive angiography. Patients with intermediate LMD had a higher risk of cardiovascular events in the unadjusted but not in the fully adjusted model compared with those without intermediate LMD. An invasive strategy increased procedural MI and decreased nonprocedural MI with no significant difference for other outcomes including the primary end point. There was no meaningful heterogeneity of treatment effect based on intermediate LMD status except for nonprocedural MI for which there was a greater absolute reduction with invasive management in the intermediate LMD group (-6.4% versus -2.0%; Pinteraction=0.049). The invasive strategy improved angina-related quality of life and the benefit was durable throughout follow-up without significant heterogeneity based on intermediate LMD status.

CONCLUSIONS

In the ISCHEMIA trial, there was no meaningful heterogeneity of treatment benefit from an invasive strategy regardless of intermediate LMD status except for a greater absolute risk reduction in nonprocedural MI with invasive management in those with intermediate LMD. An invasive strategy increased procedural MI, reduced nonprocedural MI, and improved angina-related quality of life.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT01471522.

Outcomes of Participants With Diabetes in the ISCHEMIA Trials

BACKGROUND

Among patients with diabetes and chronic coronary disease, it is unclear if invasive management improves outcomes when added to medical therapy.

METHODS

The ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) trials (ie, ISCHEMIA and ISCHEMIA-Chronic Kidney Disease) randomized chronic coronary disease patients to an invasive (medical therapy + angiography and revascularization if feasible) or a conservative approach (medical therapy alone with revascularization if medical therapy failed). Cohorts were combined after no trial-specific effects were observed. Diabetes was defined by history, hemoglobin A1c ≥6.5%, or use of glucose-lowering medication. The primary outcome was all-cause death or myocardial infarction (MI). Heterogeneity of effect of invasive management on death or MI was evaluated using a Bayesian approach to protect against random high or low estimates of treatment effect for patients with versus without diabetes and for diabetes subgroups of clinical (female sex and insulin use) and anatomic features (coronary artery disease severity or left ventricular function).

RESULTS

Of 5900 participants with complete baseline data, the median age was 64 years (interquartile range, 57-70), 24% were female, and the median estimated glomerular filtration was 80 mL·min^-1·1.73^-2 (interquartile range, 64-95). Among the 2553 (43%) of participants with diabetes, the median percent hemoglobin A1c was 7% (interquartile range, 7-8), and 30% were insulin-treated. Participants with diabetes had a 49% increased hazard of death or MI (hazard ratio, 1.49 [95% CI, 1.31-1.70]; P<0.001). At median 3.1-year follow-up the adjusted event-free survival was 0.54 (95% bootstrapped CI, 0.48-0.60) and 0.66 (95% bootstrapped CI, 0.61-0.71) for patients with diabetes versus without diabetes, respectively, with a 12% (95% bootstrapped CI, 4%-20%) absolute decrease in event-free survival among participants with diabetes. Female and male patients with insulin-treated diabetes had an adjusted event-free survival of 0.52 (95% bootstrapped CI, 0.42-0.56) and 0.49 (95% bootstrapped CI, 0.42-0.56), respectively. There was no difference in death or MI between strategies for patients with diabetes versus without diabetes, or for clinical (female sex or insulin use) or anatomic features (coronary artery disease severity or left ventricular function) of patients with diabetes.

CONCLUSIONS

Despite higher risk for death or MI, chronic coronary disease patients with diabetes did not derive incremental benefit from routine invasive management compared with initial medical therapy alone. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01471522.

Initial Invasive Versus Conservative Management of Stable Ischemic Heart Disease in Patients With a History of Heart Failure or Left Ventricular Dysfunction: Insights From the ISCHEMIA Trial

BACKGROUND

Whether an initial invasive strategy in patients with stable ischemic heart disease and at least moderate ischemia improves outcomes in the setting of a history of heart failure (HF) or left ventricular dysfunction (LVD) when ejection fraction is ≥35% but <45% is unknown.

METHODS

Among 5179 participants randomized into ISCHEMIA (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches), all of whom had left ventricular ejection fraction (LVEF) ≥35%, we compared cardiovascular outcomes by treatment strategy in participants with a history of HF/LVD at baseline versus those without HF/LVD. Median follow-up was 3.2 years.

RESULTS

There were 398 (7.7%) participants with HF/LVD at baseline, of whom 177 had HF/LVEF >45%, 28 HF/LVEF 35% to 45%, and 193 LVEF 35% to 45% but no history of HF. HF/LVD was associated with more comorbidities at baseline, particularly previous myocardial infarction, stroke, and hypertension. Compared with patients without HF/LVD, participants with HF/LVD were more likely to experience a primary outcome composite of cardiovascular death, nonfatal myocardial infarction, or hospitalization for unstable angina, HF, or resuscitated cardiac arrest (4-year cumulative incidence rate, 22.7% versus 13.8%; cardiovascular death or myocardial infarction, 19.7% versus 12.3%; and all-cause death or HF, 15.0% versus 6.9%). Participants with HF/LVD randomized to the invasive versus conservative strategy had a lower rate of the primary outcome (17.2% versus 29.3%; difference in 4-year event rate, -12.1% [95% CI, -22.6 to -1.6%]), whereas those without HF/LVD did not (13.0% versus 14.6%; difference in 4-year event rate, -1.6% [95% CI, -3.8% to 0.7%]; P interaction = 0.055). A similar differential effect was seen for the primary outcome, all-cause mortality, and cardiovascular mortality when invasive versus conservative strategy-associated outcomes were analyzed with LVEF as a continuous variable for patients with and without previous HF.

CONCLUSIONS

ISCHEMIA participants with stable ischemic heart disease and at least moderate ischemia with a history of HF or LVD were at increased risk for the primary outcome. In the small, high-risk subgroup with HF and LVEF 35% to 45%, an initial invasive approach was associated with better event-free survival. This result should be considered hypothesis-generating. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01471522.

Initial Invasive or Conservative Strategy for Stable Coronary Disease

BACKGROUND

Among patients with stable coronary disease and moderate or severe ischemia, whether clinical outcomes are better in those who receive an invasive intervention plus medical therapy than in those who receive medical therapy alone is uncertain.

METHODS

We randomly assigned 5179 patients with moderate or severe ischemia to an initial invasive strategy (angiography and revascularization when feasible) and medical therapy or to an initial conservative strategy of medical therapy alone and angiography if medical therapy failed. The primary outcome was a composite of death from cardiovascular causes, myocardial infarction, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest. A key secondary outcome was death from cardiovascular causes or myocardial infarction.

RESULTS

Over a median of 3.2 years, 318 primary outcome events occurred in the invasive-strategy group and 352 occurred in the conservative-strategy group. At 6 months, the cumulative event rate was 5.3% in the invasive-strategy group and 3.4% in the conservative-strategy group (difference, 1.9 percentage points; 95% confidence interval [CI], 0.8 to 3.0); at 5 years, the cumulative event rate was 16.4% and 18.2%, respectively (difference, -1.8 percentage points; 95% CI, -4.7 to 1.0). Results were similar with respect to the key secondary outcome. The incidence of the primary outcome was sensitive to the definition of myocardial infarction; a secondary analysis yielded more procedural myocardial infarctions of uncertain clinical importance. There were 145 deaths in the invasive-strategy group and 144 deaths in the conservative-strategy group (hazard ratio, 1.05; 95% CI, 0.83 to 1.32).

CONCLUSIONS

Among patients with stable coronary disease and moderate or severe ischemia, we did not find evidence that an initial invasive strategy, as compared with an initial conservative strategy, reduced the risk of ischemic cardiovascular events or death from any cause over a median of 3.2 years. The trial findings were sensitive to the definition of myocardial infarction that was used. (Funded by the National Heart, Lung, and Blood Institute and others; ISCHEMIA ClinicalTrials.gov number, NCT01471522.).

[Improvement of Psychosomatic Rehabilitation after Prestationary Intervention]

Aim of the study: Improvement of psychosomatic rehabilitation efforts with prestationary intervention. Method: The study is designed as a prospective and randomisized interventon study including 317 in patients. Result: Most of the patients were women (69.4 %), the mean age was 50.2 years. As measured with the BDI-II patients with prestationary intervention improved more than patients without intervention. The motivation has not been changed significantly in both treatment arms. Various independent cofactors like long duration of unemployment, disablement and patients who apply to pension were identified. Conclusion: Finally a prestationary telephon interview improves the results of psychosomatic rehabilitation measured with BDI.

Rheology of human blood plasma: viscoelastic versus Newtonian behavior

We investigate the rheological characteristics of human blood plasma in shear and elongational flows. While we can confirm a Newtonian behavior in shear flow within experimental resolution, we find a viscoelastic behavior of blood plasma in the pure extensional flow of a capillary breakup rheometer. The influence of the viscoelasticity of blood plasma on capillary blood flow is tested in a microfluidic device with a contraction-expansion geometry. Differential pressure measurements revealed that the plasma has a pronounced flow resistance compared to that of pure water. Supplementary measurements indicate that the viscoelasticity of the plasma might even lead to viscoelastic instabilities under certain conditions. Our findings show that the viscoelastic properties of plasma should not be ignored in future studies on blood flow.

Oral glucose tolerance test and HbA₁c for diagnosis of diabetes in patients undergoing coronary angiography: [corrected] the Silent Diabetes Study

AIMS/HYPOTHESIS

The primary aim of this study was to compare the results of HbA(1c) measurements with those of an OGTT for early diagnosis of 'silent diabetes' in patients with coronary artery disease (CAD) undergoing angiography without prediagnosed diabetes. A secondary aim was to investigate the correlation between the extent of CAD and the glycaemic status of the patient.

METHODS

Data from 1,015 patients admitted for acute (n = 149) or elective (n = 866) coronary angiography were analysed. Patients with known diabetes were excluded from the study. Using the OGTT results, patients were classified as having normal glucose tolerance (NGT), impaired fasting glucose (IFG), impaired glucose tolerance (IGT) or diabetes. According to the results of the HbA(1c) measurements, patients were classified into three groups: normal (HbA(1c) <5.7% [<39 mmol/mol]), borderline (HbA(1c) 5.7-6.4% [39-47 mmol/mol]) and diabetes (HbA(1c) ≥6.5% [≥48 mmol/mol]).

RESULTS

Based on the OGTT, 513 patients (51%) were classified with NGT, 10 (1%) with IFG, 349 (34%) with IGT and 149 (14%) were diagnosed with diabetes. According to HbA(1c) measurements, 588 patients (58%) were classified as normal, 385 (38%) as borderline and 42 (4%) were diagnosed with diabetes. The proportion of patients with IGT and diabetes increased with the extent of CAD (IGT ρ = 0.14, p < 0.001, diabetes ρ = 0.09, p = 0.01). No differences in HbA(1c) were seen among the groups with different extents of CAD (p = 0.652).

CONCLUSIONS/INTERPRETATION

An OGTT should be performed routinely for diagnosis of diabetes in patients with CAD undergoing coronary angiography, since HbA(1c) measurement alone appears to miss a substantial proportion of patients with silent diabetes. A limitation of the study is that the OGTT was not performed before the angiography.

Pancreatic pseudocyst with biliary fistula: treatment with endoscopic internal drainage

Surgical drainage is the standard treatment for pancreatic pseudocysts and their complications. However, acute symptomatic pancreatic pseudocysts are amenable to endoscopic internal drainage in select cases. We report a case of pancreatic pseudocyst with biliary fistula resulting from a recurrent pseudocyst treated with endoscopic stent drainage.

Cellular effects of hypercholesterolemia in modulation of cancer growth and metastasis: a review of the evidence

Hypercholesterolemia and increased cancer risk have been associated, particularly with the high fat diets characteristic of Western societies. We were interested in the possible association between preexisting hypercholesterolemia and the rapidity and extent of tumor metastases in these patients. To date there has been only a few studies that have suggested and explored this determinant of cancer metastases although it may play a role in a subset of patients who develop cancers. This article will review the literature on the effects of LDL-cholesterol on cell proliferation and differentiation and speculate on mechanisms of involvement of a hypercholesterolemic milieu on cancer progression and enhancement of metastatic potential.

A case presentation and review of neutropenic enterocolitis

Neutropenic enterocolitis (NE) is an unusual complication of neutropenia. Its presentation is dramatic, treatment is controversial, and the outcome may be devastating. The available literature about this entity is mainly case reports and autopsy studies. We have recently performed a celiotomy on a patient who developed sepsis and an acute surgical abdomen three days following chemotherapy and radiotherapy for a metastatic adenocarcinoma with no known primary tumor. At surgery he was found to have a boggy right and recto-sigmoid colon with a grossly normal transverse colon. Intraoperative colonoscopy revealed mucosal ulceration and necrosis extending from the dentate line to the cecum. A total abdominal colectomy, closure of the rectal stump, and an ileostomy was performed. Postoperatively, the patient recovered from the abdominal septic process only to succumb to multiple system organ failure secondary to pulmonary sepsis. Upon review of the literature, we found 65 cases of NE that were suspected or diagnosed in the antemortem state and confirmed at surgery or autopsy. In this review, we intend to analyze these case reports, summarize the salient features of the disease and outline the optimal therapeutic approach.

Squamous cell carcinoma complicating idiopathic inflammatory bowel disease

Squamous cell carcinoma of the colon and rectum, originating proximal to the transitional zone, is a rare complication of idiopathic inflammatory bowel disease (IIBD). To date there are only 15 single case reports of such an occurrence. This carcinoma develops more commonly in females and in patients with pancolonic disease of more than 8 years' duration. The rectum is affected in two thirds of the cases. Squamous cell changes, in the vicinity of the primary adenocarcinoma, are present in 27% of cases. The carcinoma is in a pathologically advanced stage in one third of the cases. Colectomy is the main therapeutic modality. Survival following surgical resection ranged from 7 months to 21 years. We present an additional case of rectal squamous cell carcinoma (SCC) complicating chronic ulcerative colitis in a 33-year-old woman who had the disease for 15 years. Multiple biopsies of a gross lesion located 5 cm above the dendate line were consistent with invasive basaloid cell carcinoma. The patient received 5-FU, mitomycin C, and radiotherapy prior to a proctocolectomy and ileostomy. The only histopathologic finding at pathologic review of the surgical specimen was severe squamous dysplasia.

Preoperative fasting improves survival after 90% hepatectomy

OBJECTIVE

To assess whether alterations in preoperative fatty acid oxidation and gluconeogenesis induced by fasting will affect survival and liver regeneration following 90% hepatectomy in the rat.

DESIGN

In a randomized, controlled trial, Wistar rats (N = 157) were separated into two groups. Rats in the first group fasted for 24 hours. Rats in the second group were allowed to eat ad libitum until the time of operation. These groups were further randomized to receive either 20% glucose or tap water ad libitum postoperatively.

INTERVENTIONS

Ninety percent hepatectomy; 24-hour fast; 5% glucose feeding.

MAIN OUTCOME MEASURES

Survival, DNA synthesis in the hepatic remnant along with glucokinase activity (GKA) and glycogen content, serum ketone bodies (KB), free fatty acid (FFA), glucose, and ad libitum glucose consumption (GC) were serially quantified.

RESULTS

Fasting rats that were offered glucose (fasted/glucose) after hepatectomy demonstrated better survival at 48 hours than the rats that were fed before the procedure and given glucose following hepatectomy (fed/glucose), 95% vs 52% (P < .05). The fasted/glucose group also had a greater peak rate of DNA synthesis (550 +/- 110 vs 275 +/- 40 disintegrations per minute per 0.001 mg of DNA, P < .05). Survival was poor in both groups when only tap water was offered to the animals after hepatectomy (31% vs 12%). In the fasted/glucose group, GC 1 hour after hepatectomy was greater than that for fed rats (1.3 +/- 0.175 vs 0.73 +/- 0.176 g/h, P < .05), yet GKA was suppressed (3.4 +/- 0.42 vs 8.05 +/- 2.77 nmol/min per milligrams of protein, P < .05). Fasting before hepatectomy and consuming glucose after causes elevations in both FFA (1.26 +/- 0.19 vs 0.82 +/- 0.13 mol/mL., P < .05) and KB (18.96 +/- 2.82 vs 11.4 +/- 3.94 mmol/mL, P < .05). Normal glucose was maintained in the fasted/glucose group, but fell to 63 +/- 14 mg/dL at 8 hours after hepatectomy in the fed/glucose group.

CONCLUSIONS

Fasting before hepatectomy shifts energy utilization to fat oxidation and gluconeogenesis, which appears to ameliorate liver failure after hepatectomy in this severe model of hepatic resection.

Colon cancer in blacks: age-related presentation and survival within a similar socioeconomic group

Young blacks with colon cancer continue to have a poor survival rate for reasons that remain undetermined. Medical records of blacks with colon cancer diagnosed at an inner-city hospital during a 10-year period were reviewed. The cohort consisted of 118 indigent, nonmigratory patients grouped by age. Group 1 consisted of 11 patients under age 50, and group 2 consisted of 107 patients age 50 and over. Admission symptoms were significantly different between groups. Patients in group 1 presented with abdominal pain more often than patients in group 2, and none of the patients in group 1 had anemia or obstruction, which comprised 14% and 11%, respectively, of the presenting symptoms in group 2 patients. Overall, survival difference was significant; the survival rate was 22.8 months for group 1 and 64.2 months for group 2 (P < .02). There was no difference in stage at presentation to account for the decreased survival in group 1. It is possible that the overwhelming majority (45%) of patients in group 1 with abdominal pain actually had more virulent disease, which accounts for the short survival. These individuals must be targeted for more aggressive patient education, surveillance, early detection and treatment, and follow-up.

Surgical management of advanced squamous cell skin cancers

Squamous cell cancer of the skin usually follows prolonged exposure to known carcinogens including ultraviolet light, ionizing radiation, chronic infection or irritation, chemicals, and immunologic suppression. The majority of squamous cell skin cancers metastasize infrequently and can be cured with aggressive wide local excision. However, on occasion they can be quite aggressive locally, with or without associated distant metastasis, and may require a radical surgical approach. We report a series of four male patients covering the spectrum of this disease with the following distribution: lower pole of the right ear, right posterior thigh below gluteal fold with positive inguinal nodes, lateral aspect of the foot with bone involvement, and as an incidental finding in a pilonidal cyst. We conclude that one should not hesitate to proceed with aggressive surgical resection as it may provide the only chance for cure. Finally, one should always look for lymph node metastasis, particularly with large (> 5 cm) lesions adjacent to a regional lymph node drainage basin.

Utility of an oral examination in a surgical clerkship

To evaluate the utility of the oral examination in a surgical clerkship, we designed a prospective and randomized study to relate the subjective impressions of experienced examiners with an objective measure of cognitive knowledge. The examiners were asked to score the student's performance as honors, high satisfactory, satisfactory, or unsatisfactory, according to their subjective impression of the student's ability. Student performance was grouped according to oral examination performance. The cognitive performance in the honors group was significantly better than that of the other groups (Student's t-test, p = 0.05). There was a significant difference in cognitive performance for oral examination groups throughout the rotations (analysis of variance, p = 0.000; Kruskal Wallis, p = 0.05). The oral examination is useful to identify a high level of cognitive achievement but cannot discriminate between groups of median to low competence. It should be used for educational feedback, career counseling, residency recommendations, and professional development.

Intravascular ultrasound to assess aortocoronary venous bypass grafts in vivo

In 20 consecutive patients (18 men and 2 women, aged 42 to 72 years) undergoing repeat coronary angiography because of new onset of angina pectoris 4 months to 11 years (mean 53 months) after aortocoronary saphenous venous bypass operation, the graft to the left anterior descending (n = 12), left circumflex (n = 4) or right coronary (n = 2) artery, or a diagonal branch (n = 2) was studied by both intravascular ultrasound and angiography. Sonographic images were obtained using a 4.8Fr catheter with a crystal mechanically rotated at 900 rpm; quantitative coronary angiograms were recorded in biplane projections. In 18 patients, qualitatively as well as quantitatively evaluable images could be recorded; no complications occurred. The venous wall in general appeared to be homogenous; there were no separate layers identifiable. Simultaneous ultrasound and angiographic measurements were performed at a total of 75 sites (2 to 6 per bypass). In 4 of these patients (10 of 75 sites), neither intravascular ultrasound nor angiography revealed any pathologic changes; these bypasses were classified as normal. At the remaining 65 sites, arteriosclerotic lesions were detected in each case by ultrasound, but at only 33 sites by angiography. Median wall thickness was 0.59 mm (95% confidence interval 0.54 to 0.63) in normal grafts and 1.02 mm (0.99 to 1.07; p less than 0.001) in diseased grafts. The cross-sectional luminal area determined by ultrasound correlated well with the angiographic assessment (r = 0.90; p less than 0.001), but the measured values were significantly higher (17 +/- 4 vs 14 +/- 4 mm2; p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Value of electrocardiographic scoring systems for the assessment of thrombolytic therapy in acute myocardial infarction. The European Cooperative Study Group for Recombinant Tissue Type Plasminogen Activator

The value of the Selvester and Cardiac Infarction Injury Scores was assessed in a randomized, placebo-controlled study of intravenous recombinant tissue plasminogen activator (rt-PA) in 721 patients with acute myocardial infarction. Electrocardiograms (ECG) obtained at admission, 6 h and 10 to 22 days after the start of therapy were analysed. Patients with prior myocardial infarction or QRS duration greater than or equal to 120 ms were excluded, leaving 322 in the rt-PA group and 333 in the placebo group. Cumulative 72-h release of alpha-hydroxybutyrate dehydrogenase (HBDH) and global ejection fraction derived from angiography and nuclear scintigraphy were used as independent measures of infarct size. Predischarge results demonstrated a net benefit of rt-PA therapy, with the Selvester Score 11% lower (P less than 0.01) and the Cardiac Infarction Injury Score 5.4% lower (P = NS) in the rt-PA than the control group. Total enzyme release was reduced by 19.2% (P less than 0.001) in the rt-PA group. In patients with inferior infarction, neither enzyme release (r = 0.30 to 0.40) nor ejection fraction (r = 0.22 to 0.31) correlated well with the ECG indices of infarct size. In anterior infarction, the correlations were better, especially between the Selvester Score and enzyme release (r = 0.40 to 0.48) as well as ejection fraction (r = -0.48 to -0.67). It is concluded that ECG scoring systems, especially the Selvester Score, although imperfect are useful to assess thrombolytic therapy in clinical trials. However, their value for the management and assessment of thrombolytic therapy in individual patients is still limited.

The effects of the bioflavonoid quercetin on squamous cell carcinoma of head and neck origin

Quercetin exhibits antitumor activity. We investigated the effect of quercetin on the in vitro and in vivo growth of two squamous cell carcinoma cell lines and a normal human lung fibroblast-like cell line. The in vivo effect was evaluated using implantable cell growth chambers implanted subcutaneously in immunocompetent rats. Quercetin was injected intraperitoneally, and multiple dosages were tested. Cells were counted on days 1, 3, 5, and 7, and growth curves were constructed. Quercetin caused inhibition of growth in both squamous cell carcinoma lines. Effect on the fibroblast-like human lung cells was noted only at the maximum concentration. Significant growth inhibition of squamous cell carcinoma was observed in implantable cell growth chambers retrieved 3 days after quercetin treatment. Quercetin appears to possess a cytotoxic effect on squamous cell carcinoma of head and neck origin both in vivo and in vitro. The inhibitory effect on malignant cells appears to be selective and dose-dependent.

Chemosensitivity of squamous cell carcinoma grown in implantable chambers

This study was motivated by the need to develop new methods to predict tumor response to chemotherapeutic agents. Using implantable cell-growth chambers, squamous carcinoma cells from head and neck tumors were xenografted into the peritoneal cavity of immunocompetent rats. Animals were divided into control and treatment groups. The treatment groups received intravenous cisplatin (CDDP) or 5-fluorouracil (5-FU) v normal saline solution for the control. Animals from each group were randomly selected and killed on days 3, 5, and 7 postimplantation. The chambers were retrieved, the media aspirated, and cells counted. Exponential growth curves were derived for the control and treatment groups. Statistically significant growth inhibition was observed for both treatment arms, compared with controls. This method of chemosensitivity testing proved to be inexpensive and reliable, and demonstrated tumor cell killing by 5-FU and CDDP.

Partial hepatectomy augments the liver's antitumor response

Despite adequate locoregional control, colorectal metastasis to the liver remains a significant cause of death. Resection of hepatic metastasis improves five-year survival 18% to 34%. A study of the impact of 40% partial hepatectomy on cytokine production in the liver was undertaken. Nonparenchymal liver cells (NPCs) were prepared by collagenase perfusion and metrizamide gradient from partially hepatectomized and laparotomized control C57BL/6Ros mice. Nonparenchymal cell from partially hepatectomized mice compared with laparotomized mice showed a twofold to threefold increase in interferon (IFN) activity. Both interferon alpha/beta and supernatants from cultured NPCs of partially hepatectomized mice suppressed the proliferation of liver-derived MCA-38 colon adenocarcinoma cells in vitro. This tumor has been shown to metastasize to the liver of C57BL/6Ros mice. The production of various cytokines by NPCs induced by partial hepatectomy may provide a possible antimetastatic mechanism.

Clonal growth of tumors on tissue-specific biomatrices and correlation with organ site specificity of metastases

We have found that neoplastic transformation alters the ability of cells to grow on substrata of tissue extracts, "biomatrices", enriched in extracellular matrix. Tumor cells were able to survive and grow at lower densities and on more types of biomatrices than normal cells. When plated at high densities (greater than 10(5) cells/60 mm dish), tumor cells attached with equal efficiency and grew at similar rates and to equivalent saturation densities on biomatrices derived from all tissues. However, at low (10(2)-10(4)/60-mm dish) seeding densities, the tumor cells grew only on certain types of biomatrix. For the various hepatoma and mammary carcinoma cell lines tested, the tissue specificity in clonal growth on biomatrices correlated with their organ site specificity for metastasis in vivo in immunosuppressed, athymic nude mice. Analysis of the effects of purified matrix components (adhesion proteins, collagens, glycosaminoglycans) indicated that only the glycosaminoglycans influenced density-dependent survival and growth of tumor cells with effects that differed with respect to the cell's metastatic potential. The results indicate that the ability of tumor cells to colonize specific tissues represents, in part, regulation of low density survival and growth by extracellular matrix and are suggestive that one of the matrix components responsible may be proteoglycans or their glycosaminoglycan chains.

Effects of radiotherapy on mandibular reconstruction plates

The radiation dose in the vicinity of metal mandibular implants was measured using lithium fluoride (TLD-100) thermoluminescent dosimeters. Dosimeters were positioned in contact with Vitallium and stainless steel (AO) reconstruction plates. Simple transmission was measured with a solid state detector removed from the implant at a depth of 2.5 cm in a polystyrene phantom. The measurements were made for a 6 mV photon beam from a linear accelerator. At points in front of, but in contact with the metal implants, the dose was greater by 23 percent for Vitallium and 17 percent for stainless steel than that with no implant. At contact behind the implant, the dose was reduced considerably: 14 percent for Vitallium and 13 percent for stainless steel. At remote points behind the implant, the dose was reduced due to attenuation.

Early recovery of left ventricular function after thrombolytic therapy for acute myocardial infarction: an important determinant of survival

Thrombolytic therapy for acute myocardial infarction reduces early mortality, but full recovery of left ventricular function after reperfusion is delayed. Therefore, the relations among reperfusion, survival and the time course of left ventricular functional recovery were examined in 226 patients treated with intracoronary streptokinase; 77% (134 patients) had sustained reperfusion and 31 patients had no reperfusion or had reocclusion by day 3. Wall motion was measured from contrast ventriculograms performed in the acute period and 3 days later in the central and peripheral infarct regions and the noninfarct region by the centerline method in 165 patients. Patients with reperfusion had better survival (p less than 0.05, mean follow-up 4.5 years) and a higher ejection fraction at 3 days (52 +/- 12 versus 46 +/- 10%, p less than 0.02) attributable to a significantly different change in peripheral infarct region function between the acute and 3 day studies (0.1 +/- 1.0 versus -0.3 +/- 0.9 SD, p less than 0.05). These early functional changes were significant in patients with anterior myocardial infarction and showed similar trends in those with inferior myocardial infarction. On Cox regression analysis, function measured at 3 days was more predictive of survival than was function measured acutely (chi square for acute ejection fraction = 11.48 versus 24.59 at 3 days). Although, as previously reported, greater than 45% of total recovery of left ventricular function occurs later, the ejection fraction achieved by day 3 is already predictive of survival. Thus, the mechanism by which successful thrombolytic therapy enhances survival is improvement of regional and global left ventricular function early after acute myocardial infarction.

QRS mapping in the evaluation of acute anterior myocardial infarction

In 42 patients with acute anterior myocardial infarction (AMI), we studied the course of Q-wave development and R-wave reduction during the first 48 hours after the onset of chest pain. We used precordial mapping in relation to clinical features, hemodynamic measurements and enzyme release. Q waves developed within 6-14 hours (mean 9 hours) after onset of symptoms. R-wave amplitudes demonstrated nearly a reflected image: They reduced abruptly 5-11 hours (mean 9 hours) after onset of chest pain, coinciding with ST-segment elevation. In 14 patients (group A, 33%) after initial QRS alterations, there were no further changes. Twenty patients (group B, 48%) had a distinct new increase of Q waves (delta sigma Q = 3.0 +/- 2.0 mV/hours) and further R-wave reduction (-delta sigma R = 1.0 +/- 0.6 mV/hour) simultaneous with new severe chest pain and a delayed second increase of enzyme release corresponding with extension of infarction. There were no significant differences between the groups in age, hemodynamics and infarct size calculated from creatine kinase release. Eight patients (group C, 19%) had contradictory findings. Our findings are consistent with previous results indicating that the critical period for intervention is very small except in patients with extension of necrosis.

[Clinical value of multiple praecordial chest leads for evaluating the course of acute anterior myocardial infarction (author's transl)]

Percordial ST-segment mapping using an improved 48-lead system was evaluated 2-to-3-hourly in 322 single measurements on 24 patients with acute anterior myocardial infarction. Changes in the sum of ST-elevation (capital sigma ST) or in the number of leads with ST-elevation (NST) could be distinguished in two different phases: an initial rapid increase and decrease in capital sigmaST and NST was followed after 6 to 12 hours, by a more plateau-like course, which exhibited, especially in uncomplicated cases, only slight further changes. During the initial phase, marked differences in the maximal rate of decrease were observed for capital sigma ST and NST. In this phase, interpretation of therapeutical interventions using changes of capital sigma ST or NST as reference is therefore very critical. However, during the second plateau-like phase, extension of myocardial necroses is significantly associated with a new steep increase in capital sigma ST. Thus precordial mapping is suitable for rapid and sensitive detection of infarct extension in patients with anterior myocardial infarction. The development of pericarditis or bundle-branch block, which principally can disturb the evaluation of capital sigma ST and NST, occurred only sporadically in a few patients and therefore caused no major problems.