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N-acetylcysteine administration prevents nonthyroidal illness syndrome in patients with acute myocardial infarction: a randomized clinical trial.
Vidart, J, Wajner, SM, Leite, RS, Manica, A, Schaan, BD, Larsen, PR, Maia, AL
The Journal of clinical endocrinology and metabolism. 2014;(12):4537-45
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Abstract
CONTEXT The acute phase of the nonthyroidal illness syndrome (NTIS) is characterized by low T3 and high rT3 levels, affecting up to 75% of critically ill patients. Oxidative stress has been implicated as a causative factor of the disturbed peripheral thyroid hormone metabolism. OBJECTIVE The objective of the study was to investigate whether N-acetylcysteine (NAC), a potent intracellular antioxidant, can prevent NTIS in patients with acute myocardial infarction. DESIGN This was a randomized, multicenter clinical trial. SETTINGS Consecutive patients admitted to the emergency and intensive care units of two tertiary hospitals in southern Brazil were recruited. Patients and intervention included 67 patients were randomized to receive NAC or placebo during 48 hours. Baseline characteristics and blood samples for thyroid hormones and oxidative parameters were collected. MAIN OUTCOME Variation of serum T3 and rT3 levels was measured. RESULTS Baseline characteristics were similar between groups (all P > .05). T3 levels decreased in the placebo group at 12 hours of follow-up (P = .002) but not in NAC-treated patients (P = .10). Baseline rT3 levels were elevated in both groups and decreased over the initial 48 hours in the NAC-treated patients (P = .003) but not in the control group (P = .75). The free T4 and TSH levels were virtually identical between the groups throughout the study period (P > .05). Measurement of total antioxidant status and total carbonyl content demonstrated that oxidative balance was deranged in acute myocardial infarction patients, whereas NAC corrected these alterations (P < .001). CONCLUSIONS NAC administration prevents the derangement in thyroid hormone concentrations commonly occurring in the acute phase of acute myocardial infarction, indicating that oxidative stress is involved in the NTIS pathophysiology.
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ALLHAT findings revisited in the context of subsequent analyses, other trials, and meta-analyses.
Wright, JT, Probstfield, JL, Cushman, WC, Pressel, SL, Cutler, JA, Davis, BR, Einhorn, PT, Rahman, M, Whelton, PK, Ford, CE, et al
Archives of internal medicine. 2009;(9):832-42
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Abstract
The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) is reevaluated considering information from new clinical trials, meta-analyses, and recent subgroup and explanatory analyses from ALLHAT, especially those regarding heart failure (HF) and the association of drug treatment with new-onset diabetes mellitus (DM) and its cardiovascular disease (CVD) consequences. Chlorthalidone was superior to (1) doxazosin mesylate in preventing combined CVD (CCVD) (risk ratio [RR], 1.20; 95% confidence interval [CI], 1.13-1.27), especially HF (RR, 1.80; 95% CI, 1.40-2.22) and stroke (RR, 1.26; 95% CI, 1.10-1.46); (2) lisinopril in preventing CCVD (RR, 1.10; 95% CI, 1.05-1.16), including stroke (in black persons only) and HF (RR, 1.20; 95% CI, 1.09-1.34); and (3) amlodipine besylate in preventing HF, overall (by 28%) and in hospitalized or fatal cases (by 26%). Central independent blinded reassessment of HF hospitalizations confirmed each comparison. Results were consistent by age, sex, race (except for stroke and CCVD), DM status, metabolic syndrome status, and renal function level. Neither amlodipine nor lisinopril was superior to chlorthalidone in preventing end-stage renal disease overall, by DM status, or by renal function level. In the chlorthalidone arm, new-onset DM was not significantly associated with CCVD (RR, 0.96; 95% CI, 0.88-2.42). Evidence from subsequent analyses of ALLHAT and other clinical outcome trials confirm that neither alpha-blockers, angiotensin-converting enzyme inhibitors, nor calcium channel blockers surpass thiazide-type diuretics (at appropriate dosage) as initial therapy for reduction of cardiovascular or renal risk. Thiazides are superior in preventing HF, and new-onset DM associated with thiazides does not increase CVD outcomes.
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Evaluation of a novel anti-ischemic agent in acute coronary syndromes: design and rationale for the Metabolic Efficiency with Ranolazine for Less Ischemia in Non-ST-elevation acute coronary syndromes (MERLIN)-TIMI 36 trial.
Morrow, DA, Scirica, BM, Karwatowska-Prokopczuk, E, Skene, A, McCabe, CH, Braunwald, E, ,
American heart journal. 2006;(6):1186.e1-9
Abstract
BACKGROUND Despite advances in antithrombotic therapies and invasive technology, the risk of recurrent ischemic complications in patients with non-ST-elevation acute coronary syndromes (NSTE-ACSs) remains substantial. Ranolazine is a novel agent that inhibits the late sodium current thereby reducing cellular sodium and calcium overload and has been shown to reduce ischemia in patients with chronic stable angina. STUDY DESIGN MERLIN-TIMI 36 is a phase III, randomized, double-blind, parallel-group, placebo-controlled, multinational clinical trial to evaluate the efficacy and safety of ranolazine during long-term treatment of patients with NSTE-ACS receiving standard therapy (N = 6500). Eligible patients are randomized 1:1 to ranolazine or matched placebo, initiated as 200 mg intravenously over 1 hour, followed by an 80-mg/h infusion (40 mg/h for patients with severe renal insufficiency) for up to 96 hours and oral ranolazine ER 1000 mg BID or matched placebo until the end of study. The primary end point is the time to first occurrence of any element of the composite of cardiovascular death, myocardial infarction, or recurrent ischemia. Secondary end points include ischemia on Holter monitoring, hospitalization for new or worsening heart failure, quality of life measures, and exercise performance. The evaluation of long-term safety will include death from any cause and symptomatic documented arrhythmia. Recruitment began in October 2004. The trial will continue until 730 major cardiovascular events and 310 deaths are recorded with expected completion in 24 to 28 months. CONCLUSIONS MERLIN-TIMI 36 will evaluate the role of ranolazine in the acute and chronic management of patients presenting with NSTE-ACS.
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The metabolic syndrome, circulating oxidized LDL, and risk of myocardial infarction in well-functioning elderly people in the health, aging, and body composition cohort.
Holvoet, P, Kritchevsky, SB, Tracy, RP, Mertens, A, Rubin, SM, Butler, J, Goodpaster, B, Harris, TB
Diabetes. 2004;(4):1068-73
Abstract
The object of this study was to establish the association between the metabolic syndrome and oxidized LDL (oxLDL) and to determine the risk for coronary heart disease (CHD) in relation to the metabolic syndrome and levels of oxLDL. OxLDL was measured in plasma from 3,033 elderly participants in the Health, Aging, and Body Composition study. The metabolic syndrome was defined according to criteria established in the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults. We observed that the metabolic syndrome was associated with higher levels of oxLDL due to a higher fraction of oxLDL, not to higher levels of LDL cholesterol. Individuals with the metabolic syndrome had twice the odds of having high oxLDL (>1.90 mg/dl) compared with those not having the metabolic syndrome, after adjusting for age, sex, ethnicity, smoking status, and LDL cholesterol. Among those participants who had the metabolic syndrome at study entry, incidence rates of future CHD events were 1.6-fold higher, after adjusting for age, sex, ethnicity, and smoking status. OxLDL was not an independent predictor of total CHD risk. However, those with high oxLDL showed a greater disposition to myocardial infarction (relative risk 2.25, 95% confidence interval 1.22-4.15). We concluded that the metabolic syndrome, a risk factor for CHD, is associated with higher levels of circulating oxLDL that are associated with a greater disposition to atherothrombotic coronary disease.