Comparison of an Initial Risk-Based Testing Strategy vs Usual Testing in Stable Symptomatic Patients With Suspected Coronary Artery Disease: The PRECISE Randomized Clinical Trial.

Importance: Trials showing equivalent or better outcomes with initial evaluation using coronary computed tomography angiography (cCTA) compared with stress testing in patients with stable chest pain have informed guidelines but raise questions about overtesting and excess catheterization. Objective: To test a modified initial cCTA strategy designed to improve clinical efficiency vs usual testing (UT). Design, Setting, and Participants: This was a pragmatic randomized clinical trial enrolling participants from December 3, 2018, to May 18, 2021, with a median of 11.8 months of follow-up. Patients from 65 North American and European sites with stable symptoms of suspected coronary artery disease (CAD) and no prior testing were randomly assigned 1:1 to precision strategy (PS) or UT. Interventions: PS incorporated the Prospective Multicenter Imaging Study for the Evaluation of Chest Pain (PROMISE) minimal risk score to quantitatively select minimal-risk participants for deferred testing, assigning all others to cCTA with selective CT-derived fractional flow reserve (FFR-CT). UT included site-selected stress testing or catheterization. Site clinicians determined subsequent care. Main Outcomes and Measures: Outcomes were clinical efficiency (invasive catheterization without obstructive CAD) and safety (death or nonfatal myocardial infarction [MI]) combined into a composite primary end point. Secondary end points included safety components of the primary outcome and medication use. Results: A total of 2103 participants (mean [SD] age, 58.4 [11.5] years; 1056 male [50.2%]) were included in the study, and 422 [20.1%] were classified as minimal risk. The primary end point occurred in 44 of 1057 participants (4.2%) in the PS group and in 118 of 1046 participants (11.3%) in the UT group (hazard ratio [HR], 0.35; 95% CI, 0.25-0.50). Clinical efficiency was higher with PS, with lower rates of catheterization without obstructive disease (27 [2.6%]) vs UT participants (107 [10.2%]; HR, 0.24; 95% CI, 0.16-0.36). The safety composite of death/MI was similar (HR, 1.52; 95% CI, 0.73-3.15). Death occurred in 5 individuals (0.5%) in the PS group vs 7 (0.7%) in the UT group (HR, 0.71; 95% CI, 0.23-2.23), and nonfatal MI occurred in 13 individuals (1.2%) in the PS group vs 5 (0.5%) in the UT group (HR, 2.65; 95% CI, 0.96-7.36). Use of lipid-lowering (450 of 900 [50.0%] vs 365 of 873 [41.8%]) and antiplatelet (321 of 900 [35.7%] vs 237 of 873 [27.1%]) medications at 1 year was higher in the PS group compared with the UT group (both P < .001). Conclusions and Relevance: An initial diagnostic approach to stable chest pain starting with quantitative risk stratification and deferred testing for minimal-risk patients and cCTA with selective FFR-CT in all others increased clinical efficiency relative to UT at 1 year. Additional randomized clinical trials are needed to verify these findings, including safety. Trial Registration: ClinicalTrials.gov Identifier: NCT03702244.

Deferred Testing in Stable Outpatients With Suspected Coronary Artery Disease: A Prespecified Secondary Analysis of the PRECISE Randomized Clinical Trial.

Importance: Guidelines recommend deferral of testing for symptomatic people with suspected coronary artery disease (CAD) and low pretest probability. To our knowledge, no randomized trial has prospectively evaluated such a strategy. Objective: To assess process of care and health outcomes in people identified as minimal risk for CAD when testing is deferred. Design, Setting, and Participants: This randomized, pragmatic effectiveness trial included prespecified subgroup analysis of the PRECISE trial at 65 North American and European sites. Participants identified as minimal risk by the validated PROMISE minimal risk score (PMRS) were included. Intervention: Randomization to a precision strategy using the PMRS to assign those with minimal risk to deferred testing and others to coronary computed tomography angiography with selective computed tomography-derived fractional flow reserve, or to usual testing (stress testing or catheterization with PMRS masked). Randomization was stratified by PMRS risk. Main Outcome: Composite of all-cause death, nonfatal myocardial infarction (MI), or catheterization without obstructive CAD through 12 months. Results: Among 2103 participants, 422 were identified as minimal risk (20%) and randomized to deferred testing (n = 214) or usual testing (n = 208). Mean age (SD) was 46 (8.6) years; 304 were women (72%). During follow-up, 138 of those randomized to deferred testing never had testing (64%), whereas 76 had a downstream test (36%) (at median [IQR] 48 [15-78] days) for worsening (30%), uncontrolled (10%), or new symptoms (6%), or changing clinician preference (19%) or participant preference (10%). Results were normal for 96% of these tests. The primary end point occurred in 2 deferred testing (0.9%) and 13 usual testing participants (6.3%) (hazard ratio, 0.15; 95% CI, 0.03-0.66; P = .01). No death or MI was observed in the deferred testing participants, while 1 noncardiovascular death and 1 MI occurred in the usual testing group. Two participants (0.9%) had catheterizations without obstructive CAD in the deferred testing group and 12 (5.8%) with usual testing (P = .02). At baseline, 70% of participants had frequent angina and there was similar reduction of frequent angina to less than 20% at 12 months in both groups. Conclusion and Relevance: In symptomatic participants with suspected CAD, identification of minimal risk by the PMRS guided a strategy of initially deferred testing. The strategy was safe with no observed adverse outcome events, fewer catheterizations without obstructive CAD, and similar symptom relief compared with usual testing. Trial Registration: ClinicalTrials.gov Identifier: NCT03702244.

Disparate Impact of Ischemic Injury on Regional Wall Dysfunction in Acute Anterior vs Inferior Myocardial Infarction.

BACKGROUND: Acute transmural ischemia should induce similar magnitude of wall motion abnormality (WMA) in both anterior myocardial infarction (AMI) and inferior (IMI). However, patients with AMI generally suffer more severe hemodynamic compromise. METHODS: This retrospective study compared WMA's in ST segment elevation MI patients undergoing primary reperfusion and subsequent cardiac MRI. Regional systolic wall motion and thickening were assessed in all segments throughout the left ventricle (LV). RESULTS: We analyzed 37 patients (AMI = 24 vs IMI = 13). Reperfusion success was achieved in all and there were no differences between groups in door-to-balloon time (AMI median 77 vs IMI 119 min, p = 0.085). Compared to IMI, in AMI LV ejection fraction was more depressed (37 ±â€¯7.6% vs 51 ±â€¯10.3%, P = 0.0006) and regional WMA more severe (total regional WMA score = 2.63 ±â€¯0.53 vs IMI = 2.1 ±â€¯0.52, P = 0.007). Regional dyskinesis was commonly observed in AMI patients but was rare in IMI (79% vs 7% of cases). Similarly, AMI manifested systolic thinning, whereas thickening was depressed but still present in IMI patients. Strikingly, WMA severity differed downstream relative to the origin of the infarct artery: In all AMI cases, WMA worsened from proximal anterior toward the distal apical zone; in IMI the pattern was reverse, with WMA consistently most severe in the basal segment of the inferior-posterior wall with preservation toward the apical distribution of the infarct vessel. CONCLUSION: These results demonstrate a disparate impact of ischemic injury on mechanical performance of the anterior vs inferior-posterior walls. These findings may be attributable to differences between the walls in architecture, mechanics and coronary blood flow. These observations may have implications for myocardial salvage, remodeling and prognosis.

Cognitive impairment in manic bipolar patients: important, understated, significant aspects.

BACKGROUND: Bipolar disorder is a chronic mood disorder with episodic progress and high relapse rate. Growing evidence suggests that individuals with bipolar disorder display cognitive impairment which persists even throughout periods of symptom's remission. METHOD: 137 bipolar patients met the inclusion criteria (depressive episode: DSM-IV-TR criteria for major depressive episode, HAMD score ≥17; manic/hypomanic episode: DSM-IV-TR criteria for manic/hypomanic episode, YMRS score ≥12, euthymic: 6 months of remission, HAMD score ≤8, YMRS score ≤6; and mixed: DSM-IV-TR criteria for mixed episode, HAMD score >8 and YMRS score >6) and were therefore enrolled in the study. Patients were free of psychotic symptoms (hallucinations/delusions) at the moment of testing. Control group consisted of 62 healthy subjects without history of neurological and/or psychiatric disorder. Cognitive battery has been applied in order to assess verbal memory, working memory, psychomotor speed, verbal fluency, attention and speed of information processing, and executive function. Following data were collected: demographics, psychiatric history, age of illness onset; current and previous treatment (including hospitalizations). Cognitive deficits were assessed in bipolar patients experiencing manic, depressive, mixed episodes or who were euthymic in mood. Results were compared between the subgroups and with healthy individuals. The association of impaired cognition with illness course was analyzed. RESULTS: Bipolar patients showed cognitive deficits in all evaluated domains when compared to controls. The lowest scores were obtained for the verbal fluency test. After adjusting for current episode, manic subgroup showed greater cognitive impairment in verbal and working memory, executive function/reasoning and problem solving, compared to depressive, mixed, and euthymic subgroup. Low-neurocognitive performance was directly associated with a predominance of manic episodes and severe course of bipolar illness. An increased number of past manic episodes was the strongest correlated event with the poorest outcomes in verbal memory testing. Other factors correlated with poor verbal memory scores in manic subgroup were age at illness onset (positive correlation), illness length, and hospitalizations (negative correlations). CONCLUSIONS: Bipolar patients showed cognitive deficits regardless of the phase of illness. Subjects experiencing a manic episode displayed higher deficits in verbal and working memory, executive function/reasoning, and problem solving. Severe course of illness also showed significant contribution in terms of cognitive impairment.

The Daily Functionality in a Major Depressive Episode Cohort of Romanian Patients - a Non-Interventional Study.

OBJECTIVES: The aim of this non-interventional, investigator driven study was to assess the functionality of patients with major depression under treatment with agomelatine in real life clinical practice. MATERIAL AND METHODS: The study was multicenter, non-interventional and evaluated the functionality of the adult patients with a DSM-IV diagnosis of MDD (single or recurrent episode and no treatment in the previous 6 months). It took place in Romania and it was a 10-weeks study. After the clinicians took the medical decision of treatment with agomelatine and if the patient agreed to be evaluated more accurate in this study, in order to assess functionality, patients completed at each visit the Sheehan Disability Scale (SDS). Patients were assessed also with QIDS-C (Quick Inventory of Depressive Symptomatology), a measure of depression symptoms severity and CGI scale severity (CGI-S), CGI scale improvement (CGI-I) and therapeutic index. Also, data about demographics and disease were collected during clinical interviews and from medical records. RESULTS: The functionality as assessed with SDS showed a significant functional impairment at baseline with scores >6 for each of the 3 inter-related domains of work/school, social and family life. At the end of the study, all functional aspects were improved although a mild impairment still persist requiring further treatment. A total of 1191 patients were analyzed (mean age: 47 years, 68% female). Mean QIDS-16 total score at baseline was 14.3 and decreased over the 10-week prospective period to 2.3. Most patients were treated with agomelatine. CONCLUSION: This study outcome confirms the fast on set of functionality improvement of agomelatine and further treatment need for the total remission of clinical depressive symptomatology after 10 weeks of treatment.

Validity of estimated glomerular filtration rates for assessment of renal function after renal artery stenting in patients with atherosclerotic renal artery stenosis.

OBJECTIVES: The purpose of this study was to evaluate the validity of estimates of glomerular filtration rate (eGFR) for assessing serial changes in renal function after renal artery stenting. BACKGROUND: eGFR are unreliable for assessing serial renal function in patients with atherosclerotic renal artery stenosis (RAS). eGFR have not been validated for assessment of serial renal function after renal artery stenting. METHODS: Serum creatinine (SCr) and (125)I-iothalamate GFR (iGFR) were measured in RAS patients before and after renal artery stenting. eGFR were calculated from Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), and Cockcroft-Gault (CG) formulas. Using iGFR as the reference standard, the sensitivity, specificity, and area under the receiver-operating characteristic curve (AUC) were determined for MDRD, CKD-EPI, and CG for assessing changes in GFR before and after intervention. RESULTS: Between 1998 and 2007, 84 patients underwent iGFR and eGFR before and after renal artery stenting. All eGFR demonstrated poor sensitivity and reliability for detecting ≥20% changes in iGFR, and poor agreement in the magnitude and direction of change in iGFR, before and after renal stenting. CONCLUSIONS: In RAS patients, eGFR demonstrate poor sensitivity and reliability for detecting meaningful changes in iGFR after renal artery stenting. eGFR should be abandoned as primary endpoints in major clinical trials assessing the impact of renal revascularization on renal function.

Non-high-density lipoprotein cholesterol calculation and goal awareness among physicians-in-training.

BACKGROUND: Non-high density lipoprotein cholesterol (non-HDL-C) goal attainment per Adult Treatment Panel III (ATP III) guidelines remains low. OBJECTIVE: To understand gaps in knowledge and practices of physicians-in-training (internal medicine, family medicine, cardiology, endocrinology) towards non-HDL-C. METHODS: A survey based on a conceptual model to assess the trainee's knowledge, attitudes, and practice regarding non-HDL-C was developed and administered to physicians-in-training (n = 655) at 26 training programs in the United States. Responses of those in internal medicine and family medicine (residents-in-training; n = 418) were compared with those in cardiology and endocrinology (fellows-in-training; n = 124). RESULTS: Response rate was 83.7%. Fifty-three percent of residents and 31% of fellows-in-training had not read the ATP III guidelines (P < .001). Thirty-three percent of the residents and 35% fellows-in-training could not calculate non-HDL-C from a standard lipid panel (P = .7). Sixty-seven percent of the residents and 52% of fellows were not aware of treatment goals for non-HDL-C (P = .004 for comparison between residents and fellows). Both residents and fellows reported infrequent calculation of non-HDL-C levels in patients with elevated triglycerides (≥200 mg/dL; 32.5% vs 35.4%, respectively, P = .6). Lack of familiarity with ATP III guidelines, lack of knowledge regarding importance of non-HDL-C, lack of institutional mandate to calculate non-HDL-C, and lack of emphasis on non-HDL-C by teaching staff were reported as barriers to non-HDL-C use in routine clinical practice. CONCLUSIONS: At least one-third of physicians-in-training could not calculate non-HDL-C from a standard lipid panel, and a large number were not aware of ATP III treatment goals pertaining to non-HDL-C. This area represents one for improvement if non-HDL-C is to be retained as a treatment target in the forthcoming ATP-IV guidelines.

Nutritional and micronutrient determinants of idiopathic dilated cardiomyopathy: diagnostic and therapeutic implications.

Idiopathic dilated cardiomyopathy (IDCM) is the term used to describe a group of myocardial diseases of unknown cause whose common clinical presentation is heart failure. The prevalence of IDCM is estimated to be between 7 and 13% of patients with systolic heart failure. Throughout medical history, several nutrient-deficient states have been identified as the root cause of IDCMs, Keshan's disease being one such example, where selenium deficiency-induced heart failure is now well documented. This raises the question of whether a micro- or macro-nutrient imbalance can provide the milieu for inefficient energy expenditure and cardiac metabolism in the context of IDCMs, either causing or exacerbating the condition. To date, there is insufficient evidence in the literature to support this theory, although numerous studies suggest a link between nutrient deficiencies, inefficient energy expenditure and subsequent heart failure. Given the unique metabolic needs of the failing heart, the role of micronutrient testing and supplementation in IDCMs warrants further well-designed studies.

Insights into endovascular revascularization in limb salvage procedures: "antegrade-retrograde" technique in chronic total occlusion.

Significant occlusions of the peripheral arterial circulation, responsible for chronic limb ischemia (CLI), are a serious cause of morbidity, mortality, and poor quality of life. The currently available treatment options for patients with severely symptomatic CLI include bypass surgery and arterial revascularization. Percutaneous transluminal angioplasty for CLI is shown to be as effective as bypass surgery at high-volume centers, and it also offers a less invasive alternative, leading to quicker patient recovery times and lower short-term costs. This case report reviews the current techniques available and discusses an "antegrade-retrograde" angioplasty approach to successfully recanalize such challenging obstructions.

Validity of estimated glomerular filtration rates for assessment of baseline and serial renal function in patients with atherosclerotic renal artery stenosis: implications for clinical trials of renal revascularization.

BACKGROUND: Despite routine use of estimated glomerular filtration rates (GFRs) as major renal end points in clinical trials of renal revascularization, serial GFR estimates have never been validated in patients with renal artery stenosis (RAS). The purpose of this study was to evaluate the validity of GFR estimates in patients with atherosclerotic RAS. METHODS AND RESULTS: Serum creatinine (SCr) and (125)I-iothalamate GFR (I-GFR) were measured in patients with RAS. GFR estimates were calculated from Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), and Cockroft-Gault (CG) formulas. Using I-GFR as the reference standard, the sensitivity, specificity, and receiver operating characteristic area under the curve (AUC) were determined for MDRD, CKD-EPI, CG, and reciprocal SCr for identifying I-GFR <60 mL/min per 1.73 m(2) and a 20% change in I-GFR over time. Between 1998 and 2007, 541 I-GFR measurements were performed in 254 consecutive patients with RAS. MDRD, CKD-EPI, and CG GFR estimates demonstrated good sensitivity (86% to 95%), modest specificity (67% to 71%), and good reliability (AUC, 0.86 to 0.94) for identifying I-GFR <60 mL/min per 1.73 m(2). GFR estimates had good specificity (87% to 95%), poor sensitivity (0% to 45%), and poor reliability (AUC, 0.61 to 0.65) for detecting 20% changes in I-GFR over follow-up. CONCLUSIONS: In patients with RAS, GFR estimates demonstrate good sensitivity and modest specificity for identifying I-GFR <60 mL/min per 1.73 m(2) but poor sensitivity and reliability for detecting 20% changes in I-GFR. GFR estimates should not be used in clinical trials as major end points to assess serial GFR after renal revascularization.

CHADS(2) score is predictive of left atrial thrombus on precardioversion transesophageal echocardiography in atrial fibrillation.

OBJECTIVE: The goals of this study were to determine: 1) if the CHADS(2) score correlates with left atrial (LA) or left atrial appendage (LAA) thrombus on pre-cardioversion transesophageal echocardiography (TEE) in nonvalvular atrial fibrillation (NVAF); and 2) what, if any, components of the CHADS(2) score are most important in predicting LA/LAA thrombus. BACKGROUND: It is unknown if CHADS(2) score, a marker of thromboembolic risk in NVAF, accurately predicts LA/LAA thrombus on pre-cardioversion TEE. METHODS: We retrospectively studied patients undergoing precardioversion TEE for NVAF at a tertiary hospital. TEE reports were reviewed for presence of LA/LAA thrombus. Using medical records and an ICD-9 coding database, a CHADS(2) score was derived, and the association between CHADS(2) and thrombus was evaluated with Mantel-Haenszel Chi-Square. The relation between the singular components of CHADS(2) and thrombus were analyzed using Pearson's Chi-Square. RESULTS: In 643 consecutive patients undergoing pre-cardioversion TEE, LA/LAA thrombus was identified in 46 (7.2 %). A strong association was present between CHADS(2)score and LA/LAA thrombus (p = 0.0005). No thrombi were identified in patients with CHADS(2) = 0. Among 46 patients with thrombus, all (100%) had CHF. Of the singular components, CHF was the only factor independently associated with thrombus (p < 0.0001). CONCLUSIONS: In non-valvular atrial fibrillation, CHADS(2) is strongly associated with LA thrombus on TEE. Our findings suggest pre-cardioversion TEE may be unnecessary if the CHADS(2) score = 0. Of the components of the CHADS(2) score, CHF was the only independently associated risk factor which correlated with LA/LAA thrombus.

Cardiovascular implications of proteinuria: an indicator of chronic kidney disease.

Proteinuria, defined as urine protein excretion greater than 300 mg over 24 h, is a strong and independent predictor of increased risk for all-cause and cardiovascular mortality in patients with and without diabetes. Proteinuria is a sign of persistent dysfunction of the glomerular barrier and often precedes any detectable decline in renal filtration function. Measurement of proteinuria is important in stratifying the risk for cardiovascular disease and chronic kidney disease progression. A variety of basic pathophysiologic mechanisms that can partially explain simultaneous renal and cardiac disease will be discussed in this Review. In addition to being a prognostic marker, proteinuria is being considered as a therapeutic target in cardiovascular medicine. Therapeutic strategies for amelioration of proteinuria by achieving blood pressure targets, glycemic control in diabetes, treatment of hyperlipidemia, and reducing dietary salt and protein intake are also reviewed in this paper. Future clinical studies are needed to assess if proteinuria reduction should be a target of treatment to reduce the burden of end-stage renal disease, cardiovascular disease, and improve survival in this high-risk population.

Regulation of retention of FosB intron 4 by PTB.

One effect of stressors such as chronic drug administration is that sequence within the terminal exon of the transcription factor FosB is recognized as intronic and removed by alternative splicing. This results in an open-reading-frame shift that produces a translation stop codon and ultimately a truncated protein, termed DeltaFosB. In vitro splicing assays with control and mutated transcripts generated from a fosB mini-gene construct indicated a CU-rich sequence at the 3' end of intron 4 (I4) plays an important role in regulating fosB pre-mRNA splicing due to its binding of polypyrimidine tract binding protein (PTB). PTB binding to this sequence is dependent upon phosphorylation by protein kinase A and is blocked if the CU-rich sequence is mutated to a U-rich region. When this mutated fosB minigene is expressed in HeLa cells, the splicing efficiency of its product is increased compared to wild type. Moreover, transient transfection of PTB-1 in HeLa cells decreased the splicing efficiency of a wild type fosB minigene transcript. Depletion of PTB from nuclear extracts facilitated U2AF65 binding to wild type sequence in vitro, suggesting these proteins function in a dynamic equilibrium to modulate fosB pre-mRNA alternative splicing. These results demonstrate for the first time that phosphorylated PTB promotes intron retention and thereby silences the splicing of fosB I4.

Sympathetic dysfunction in type 1 diabetes: association with impaired myocardial blood flow reserve and diastolic dysfunction.

OBJECTIVES: This study was designed to explore the relationships of early diabetic microangiopathy to alterations of cardiac sympathetic tone and myocardial blood flow (MBF) regulation in subjects with stable type 1 diabetes. BACKGROUND: In diabetes, augmented cardiac sympathetic tone and abnormal MBF regulation may predispose to myocardial injury and enhanced cardiac risk. METHODS: Subject groups comprised healthy controls (C) (n = 10), healthy diabetic subjects (DC) (n = 12), and diabetic subjects with very early diabetic microangiopathy (DMA+) (n = 16). [(11)C]meta-hydroxyephedrine ([(11)C]HED) and positron emission tomography (PET) were used to explore left ventricular (LV) sympathetic integrity and [(13)N]ammonia-PET to assess MBF regulation in response to cold pressor testing (CPT) and adenosine infusion. RESULTS: Deficits of LV [(11)C]HED retention were extensive and global in the DMA+ subjects (36 +/- 31% vs. 1 +/- 1% in DC subjects; p < 0.01) despite preserved autonomic reflex tests. On CPT, plasma norepinephrine excursions were two-fold greater than in C and DC subjects (p < 0.05), and basal LV blood flow decreased (-12%, p < 0.05) in DMA+ but not in C or DC subjects (+45% and +51%, respectively). On adenosine infusion, compared with C subjects, MBF reserve decreased by approximately 45% (p < 0.05) in DMA+ subjects. Diastolic dysfunction was detected by two-dimensional echocardiography in 5 of 8 and 0 of 8 consecutively tested DMA+ and DC subjects, respectively. CONCLUSIONS: Augmented cardiac sympathetic tone and responsiveness and impaired myocardial perfusion may contribute to myocardial injury in diabetes.

Dissection of metabolic, vascular, and nerve conduction interrelationships in experimental diabetic neuropathy by cyclooxygenase inhibition and acetyl-L-carnitine administration.

Alterations in cyclooxygenase (COX) pathway activity have been implicated in the pathogenesis of experimental diabetic neuropathy (EDN). These studies explore the relationships between COX-mediated and acetyl-L-carnitine (ALC)-sensitive defects that contribute to functional, metabolic, and vascular abnormalities of EDN. The effects of nonselective COX inhibition with flurbiprofen were contrasted with selective COX-2 inhibition with meloxicam, administered alone and in combination with ALC in nondiabetic (ND) and streptozotocin-induced diabetic (STZ-D) rats. Flurbiprofen treatment of ND rats replicated many of the biochemical and physiological abnormalities of EDN, i.e., reduced motor nerve conduction velocity (MNCV), total and endoneurial nerve blood flow (NBF), Na,K-ATPase activity, and myo-inositol (MI) and taurine content. In STZ-D rats, however, flurbiprofen paradoxically prevented endoneurial NBF deficits but not MNCV slowing. Coadministration of 50 mg x kg(-1) x day(-1) ALC prevented reductions in MNCV, Na,K-ATPase activity, and endoneurial NBF in flurbiprofen-treated ND and STZ-D rats. In contrast, selective COX-2 inhibition with meloxicam was without effect on MNCV, NBF, or MI content in ND rats and prevented MNCV slowing and NBF deficits in STZ-D rats. Western blot analysis showed unchanged sciatic nerve COX-1 protein but increased COX-2 protein abundance in STZ-D versus ND rats. These results imply 1) a tonic role of the COX-1 pathway in the regulation of nerve osmolytes and Na,K-ATPase activity and the maintenance of NBF in ND animals and 2) activation of the COX-2 pathway as an important mediator of NBF and MNCV deficits in EDN.