Statins And Biomarkers In Claudicants With Peripheral Arterial Disease: Cross-sectional Study

This exploratory substudy of The Iron (Fe) and Atherosclerosis Study (FeAST) compared baseline inflammatory markers, including cytokines, C-reactive protein (CRP), and ferritin, in subjects with peripheral arterial disease (PAD) taking statins with subjects with PAD who were not taking statins. Inflammatory markers in the serum of 47 subjects with PAD not taking statins and a healthy cohort of 21 medication-free men were compared with 53 PAD subjects taking statins at entry to the FeAST.

Healthy subjects demonstrated lower levels of tumor necrosis factor (TNF)-R1, interleukin-6 (IL-6), and CRP. TNF-α R1 averaged 2.28 ng/mL versus 3.52 ng/mL, p  =  .0025; IL-6 averaged 4.24 pg/mL versus16.61 pg/mL, p  =  .0008; and CRP averaged 0.58 mg/dL versus 0.92 mg/dL, p  =  .0192. A higher level of IL-6 was observed in PAD statin takers versus PAD subjects not taking statins: 19.47 pg/mL versus 13.24 pg/mL, p  =  .0455. As expected, total cholesterol and low-density lipoprotein levels were lower in the statin-treated group, p  =  .0006 and p  =  .0001, respectively. No significant differences in inflammatory cytokines were detected for varying doses of simvastatin. Additionally, no significant differences in inflammatory biomedical markers were found in subjects with PAD alone compared with those with concomitant coronary artery disease (CAD).

Unexpectedly, serum inflammatory cytokine IL-6 levels were significantly higher in PAD subjects receiving statins. There was no difference in measured inflammatory markers in PAD subjects with concomitant CAD.

Cytokine signatures in atherosclerotic claudicants

BACKGROUND

Iron accumulation and inflammation may affect atherosclerosis. This study intended to define a cytokine signature in atherosclerotic claudicants and to determine whether reduction in serum ferritin by phlebotomy influenced this pattern.

METHODS

Ninety-one subjects with peripheral vascular disease (PVD; mean age, 67 years) were recruited from the VA Cooperative Iron and Atherosclerosis Study (FeAST) testing the hypothesis that ferritin reduction to 25 ng/ml may ameliorate atherosclerosis. Cytokines TNF-a, IL-2, IL-6, and IL-10 were analyzed by enzyme amplified sensitivity assay (EASIA). Fasting iron and cholesterol panels, complete blood count, C-reactive protein (CRP), uric acid, fibrinogen, glucose, and hemoglobin A1c levels were also quantified. Values were compared with "healthy" controls (n = 21; mean age, 56 years). After randomization of PVD to phlebotomy (intervention group [IG], n = 44) or control (nonintervention group [NG], n = 47), analyses were compared at 6 and 12 months using t test, Wilcoxon rank sum test, chi-square, and robust MM regression.

FINDINGS

Age, glucose, and hemoglobin A1c were higher in PVD compared with healthy controls (P < 0.01), whereas serum iron (P < 0.01) and percentage of transferrin saturation (P < 0.05) were lower. Tumor necrosis factor-alpha (TNF-alpha; P < 0.05), IL-6 (P < 0.01), and CRP (P < 0.05) levels were higher in the PVD group, whereas IL-10 was lower (P < 0.01). At 6 months post phlebotomy, ferritin levels were reduced (P < 0.01), although ferritin levels were reduced less in smokers. IL-6 and fibrinogen, CRP and ferritin levels correlated positively. At 6 and 12 months, subjects with TNF-alpha (n= 15) and IL-6 (n = 10) levels in the upper 25th percentile were reduced by phlebotomy.

INTERPRETATION

An inflammatory cytokine signature exists in atherosclerosis. Elevated levels of TNF-alpha and IL-6, reportedly associated with recurrent and future myocardial infarction, were reduced by phlebotomy. The utility of the iron/inflammatory hypotheses will ultimately relate to clinical outcomes obtained prospectively by the FeAST trial.

Target selection for surgical intervention in severe chronic venous insufficiency: comparison of duplex scanning and phlebography

PURPOSE

The goal of this study was to determine whether duplex scanning (DS) alone, compared with ascending phlebography (AP) and descending phlebography (DP), would have been sufficient to guide treatment of severe chronic venous insufficiency (CVI), CEAP Clinical Classes 5 and 6.

METHODS

Beginning in 1994, patients presenting to the VA Sierra Nevada Vascular Clinic with ulceration due to CVI, CEAP Clinical Classes 5 and 6, were examined with DS, AP, and DP. Phlebography mainly guided surgical interventions. The ability of DS findings to select surgical interventions, with the aims of diversion of reflux from area of trophic skin or reduction of global venous hypertension was compared with phlebography. Of the 33 male patients (age, 29-70 years; average, 55 years) considered for operative interventions between January 1994 and November 1999, 30 were selected for operative treatment.

RESULTS

DS was 100% sensitive and specific for detection of complete occlusion of the superficial femoral vein (10/10) and for saphenous incompetence; sensitivity was 95% (19/20); and specificity was 100%. However, DS failed to reveal subtle changes in recanalized femoral veins because of prior thrombophlebitis, which was uncovered by AP in six of 23 patent femoral veins. There were 16 positive findings on AP of residual thrombophlebitis, of which six were not read on DS. Sensitivity was 63%, specificity was 100%, the positive predictive value was 100%, and the negative predictive value was 53%. Reflux grading with DP agreed with DS in 23 of 33 cases or varied by one grade in five of 33 cases: sensitivity, 82%; specificity, 75%; positive predictive value, 96%; and negative predictive value, 37%. Kistner grade 4 reflux involving the superficial femoral and popliteal veins was noted by DP in five of the 33 cases when DS described reflux as "moderate." Incompetent superficial femoral vein valve stations in the upper third of the vein, which caused primary reflux, were clearly defined by DP in four of 33 cases; valve location was not well defined by DS. Below-knee perforator identification with DS was difficult; this was related to the severity of lipodermatosclerosis and the presence of ulceration. The number of perforators described at operation with subfascial endoscopic perforator surgery (n = 13) averaged 6 +/- 2, whereas AP identified an average of 4 +/- 2 in supramalleolar area. In four men, two previously undiagnosed caval and two iliac obstructions were detected with AP; one was corrected with Palma bypass grafting. Follow-up at 4 to 60 months (average, 40 months) showed four ulcer recurrences among 30 patients who were operated on. Two patients underwent repeat operations on the basis of repeated phlebographic study and are cured at this time, one patient was healed with conservative therapy, and one patient is lost to follow-up.

CONCLUSIONS

DS would have been inadequate for identifying surgical targets in CVI, CEAP Clinical Classes 5 and 6. DS overlooked iliac and caval lesions. Potential valveplasty sites, which were only delineated on DP, resulted in four valveplasties in the upper third of the superficial femoral vein for grade 4 reflux. AP localized mid- to upper-leg perforators, but neither AP nor DP detected perforators in the range of 5 to 10 cm above the calcaneus. The net effect of phlebography was a choice for deep interventions in five (17%) of 30 cases, which would not have been possible with DS alone. The identification of iliocaval occlusion influenced the decision, based on prior experience, not to perform distal procedures in three cases.

Venous thromboembolism in trauma patients: standardized risk factors

PURPOSE

This study was done to evaluate the use of published standardized risk factors for venous thromboembolism (VTE) in patients admitted to a trauma intensive care unit (ICU) and to derive guidelines for the use of low molecular weight heparin (LMWH) and surveillance venous Doppler ultrasound scanning (VDUS).

METHODS

Patients were admitted to a regional trauma center ICU. Two periods were studied. Period 1 was a retrospective analysis of documented cases of VTE in the trauma registry from 1993 to 1995 (n=39). The period was also a review of all patients admitted to a trauma ICU in 1994 without VTE who met the following criteria: age greater than 11 years, ICU stay of more than 36 hours, and survival of more than 72 hours (n=227). Period 2 was a concurrent analysis of 1996 documented cases of VTE and similarly selected ICU admissions (VTE, n=10; no VTE, n=224). Risk factor scores (R1, admitting; R2, total) were calculated from the International Society for Cardiovascular Surgery/Society for Vascular Surgery reporting standards. The scores were cumulative by category and over time. The suitability of such standards was determined in period 1. The resulting therapeutic and surveillance guidelines were evaluated in period 2.

RESULTS

Period 1 risk factor scores, R1 and R2, were correlated with the occurrence of VTE from chi2 test (P < .05 and P < .01, respectively). Risk categories were grouped as low, moderate, and high. VTE was not observed in the low-risk group (0 to 2). Among all VTE (n=49), 11 cases occurred in patients with moderate-risk scores and 38 in patients with high-risk scores. In 1994 and 1996, the selected groups were analyzed and the incidence rate of VTE was 4.7% in both years for the moderate-risk group and 2.5% and 4.8% for the high-risk group, respectively. Most VTE cases (78%) received some form of prophylaxis (PRx), and 26% of cases had multiple methods of prophylaxis (MPRx). This included 80% of the cases that received unfractionated heparin. In period 2, no pulmonary emboli (PE) occurred, in contrast to period 1, in which 16 of 39 cases of VTE (41%) were first seen with PE. In period 2, no patient receiving MPRx, including compression and LMWH, had VTE develop. Surveillance VDUS discovered 60% of 1996 cases in period 2. No PE were seen in period 2.

CONCLUSION

Standard risk factors were easily applied to the trauma patient at the bedside. Patients at low risk needed no PRx. Patients at high risk did best with both compression devices and LMWH. VDUS was recommended selectively in patients at high risk in whom multiple-method PRx could not be achieved. Patients at moderate risk required further study to define optimal PRx and need for surveillance VDUS. Intracaval devices were used prophylactically only twice.

Carotid endarterectomy in the community hospital. A continuing controversy

A retrospective review of 390 carotid endarterectomies performed in two major private hospitals over 78 months by general and neurological surgeons, was conducted. The mortality was 3.1% including five fatal strokes. Permanent neurological deficit was noted in 7.2% of survivors. Use of an intraoperative shunt, or the occurrence of postoperative hypotension did not alter the morbidity. Postoperative hypertension was clearly detrimental, while those with a stable postoperative course fared best. General vascular surgeons were classified as having had additional cardiovascular training, special interest or occasional experience in vascular surgery. Neither training nor case load appeared to affect morbidity. Individual differences within groups were greater than between groups. Improvement of statistics was noted in the second 18 months. It is concluded that the best method to improve results in the moderate sized community with a mixed pool of surgeons is to promote open and ongoing peer review of indications and results of carotid endarterectomy.

Avoidance of postcarotid endarterectomy hypertension

To minimize extreme blood pressure changes after carotid endarterectomy, dissection methods were developed to preserve the intercarotid neural bundle supplying the carotid baroreceptors and applied to our last 90 consecutive carotid endarterectomies. Hypertension was defined as a rise in systolic blood pressure greater than 40 mmHg and hypotension as a drop of 40 mmHg in those with preoperative hypertension or a systolic blood pressure of less than 100 mmGh. There were 46 cases hypertensive before operation, and the remaining 44 were normotensive before operation. When the series was analyzed, half the patients undergoing nerve-sparing dissection became hypotensive, irrespective of pre-existing hypertension extent and bilaterality of stenoses, and preoperative neurologic deficits. Hypotension was a transient and benign process and easily controlled by catheter instillation of 2% xylocaine in the postoperative period. Hypertension, which occurred in ten patients, was equally benign; only five required treatment. There were no deaths or neurologic deficits. Nerve-sparing carotid dissection and catheter placement for block of the carotid sinus nerves are valuable methods to minimize extreme blood pressure changes after carotid endarterectomy.

Pitfalls in the diagnosis of abdominal aortic aneurysm

The lethal progression of expanding aneurysms may present as a confusing clinical picture. Four cases are reported in which the diagnosis was masked and treatment delayed by symptoms thought to be related mainly to inguinal hernias. It is concluded that there is a subset of patients with aneurysmal progression in whom symptoms are related mainly to the groin. Exhaustive diagnostic methods will detect this condition when the aneurysm is not palpable. The ability to recognize these unique symptoms and signs in elderly men presenting with enlarging inguinal hernias and neuropathy is essential. Biologic and biochemical relations between inguinal hernias and aneurysms may exist.