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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.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.This was a randomized, multicenter clinical trial.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.Variation of serum T3 and rT3 levels was measured.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).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.

Background Postinterventional ischemic myocardial dysfunction and its sequelae are still not well understood. Methods and Results To gain further insight into the immediate physiologic consequences of coronary interventions and to better understand the nature of changes that result from such interventions, we analyzed 96 electromechanical maps from 48 patients before and after successful, uncomplicated percutaneous coronary interventions (PCI). A NOGA system was used to construct the map of the endocardial surface. Reproducibility was confirmed by constructing 10 additional maps in 5 patients who did not undergo an intervening procedure. Discordant areas were defined as those with preserved unipolar voltage (≥7.5 mV) and diminished linear local shortening (≤12.5%). On the basis of comparison of the variations in the discordance values (%) in the reproducibility group, patients were considered improved (lower values), worsened (higher values), or unchanged. In the reproducibility group, the mean variation in discordance was 2.18% ± 1.26%, whereas in the PCI group, it was 21.97% ± 18.47%. In the PCI group (rotational atherectomy subgroup [n = 10] and stent subgroup [n = 38]), left ventricular discordance values improved in 19 patients (39.6%), worsened in 24 (50%), and remained the same in 5 (10.4%). Of all variables analyzed, only abciximab was significantly associated with postintervention improvement in discordance ( P =.02; odds ratio 0.165, 95% CI 0.03-0.88), regardless of the type of intervention performed ( P =.61), whereas heparin alone was associated with more discordance after intervention (odds ratio 6.07, 95% CI 1.14-32.40). Conclusions We assessed the effect of percutaneous revascularization on myocardium by use of electromechanical data. For the first time, changes in linear local shortening in areas of preserved unipolar voltage were quantified, and worsening after successful Thrombolysis In Myocardial Infarction grade III coronary interventions was registered. The only variable associated with improvement on electromechanical data after interventions was the use of abciximab. This raises the question of the possible potential of this new diagnostic tool in assessing and quantifying postinterventional microvasculature pathological changes. (Am Heart J 2002;144:693-701.)

The ability to estimate the rate of a new target vessel revascularization (TVR) after bare metal coronary stenting is an important issue, as the systematic use of drug-eluting stents is still limited by its high costs.We sought to create a predictive score for the possibility of a new TVR after bare metal stenting.Clinical and angiographic characteristics of a prospective cohort of 848 patients were included in a dedicated database. Independent predictors of 1-year TVR were identified by multivariate analysis, and the score points were assigned according to the relative risk ratio of 1-year TVR.The 1-year TVR rate in the 848 patients was 7.4%. By multivariate analysis, reference diameter, lesion length and diabetes mellitus were retained in the final model (Hosmer-Lemeshow goodness-of-fit test = 2.339; p = 0.969). The increase of 1-year TVR rates was almost linear, with each score level (0 = 1.4%, 1 = 4.5%, 2 = 7.1%, 3 = 10.4% and 4 of 5 = 15.7%; r = 0.90; p0.001), and the p of the Chi-square test for trend was0.0001.This score can stratify patients with very low and high TVR rates and can be used as a simple clinical tool for the prediction of a new revascularization procedure in daily practice.

Background— This study was designed to define myocardial viability and establish practical cut-off values for differentiating normal myocardial tissue from subendocardial and transmural scar tissue by using electromechanical mapping (EMM). We validated our results by delayed-enhancement cardiac MRI (DE-MRI). Methods and Results— We prospectively studied 15 ambulatory patients with stable coronary disease who were candidates for cardiac catheterization. Within 48 hours of EMM, DE-MRI was performed. Using EMM software, we created a bull’s eye precisely matched to that generated by DE-MRI. Segment by segment, we compared the MRI results to the corresponding unipolar voltage value for that same segment in the EMM bull’s eye. Of 300 total segments, 275 were compared. The segments were divided into normal (n=211), subendocardial scar (n=49), and transmural scar (n=15). We found that subendocardial (6.8±2.9 mV) and transmural (4.6±1.9 mV) scar segments had significantly less unipolar voltage than normal (11.6±4.5 mV) segments ( P Conclusions— Our results demonstrate that normal myocardium can be accurately distinguished from myocardium with subendocardial or transmural infarcts on the basis of unipolar voltage values obtained through EMM. This is the first study to validate these results by using cardiac DE-MRI in humans.