Myocardial fixation of anticardiac troponin I antibody and cardiac troponin I release

BACKGROUND: The threefold aim of this experimental study was to test the correlation of cardiac troponin I released to myocardial infarction size and myocardial fixation of anticardiac troponin I antibody and to determine how long after myocardial infarction the measure of cardiac troponin I concentration can evaluate myocardial infarction size. METHODS: Forty rabbits were assigned either to a control group or to an experimental preconditioned group. Infarction was obtained by tightening a snare around the left anterior descending artery. Serial venous blood samples were drawn for measurement of cardiac troponin I. The rabbits were sacrificed at 72 hours and a histological study was performed to determine the infarct size and the size of the area void of fixation of anticardiac troponin I antibody. RESULTS: There was a linear correlation between the total amount of CTn I released and both infarct size (r=0.45, p<0.02) and the size of the area void of anti-cardiac troponin I antibody (r=0.47, p<0.02). These two sizes were strongly correlated (r=0.95, p<0.02). The hour 9 CTn I sample was the best correlated with both the infarct size (r=0.47, p<0.02) and the size of area void of anticardiac troponin I antibody (r=0.45, p<0.02). CONCLUSIONS: Our study shows that: 1) cardiac troponin I release is correlated to both myocardial infarction size and the size of area void of fixation of anticardiac troponin I antibody, 2) the area void of anticardiac troponin I antibody fixation includes the whole ischemic area, and 3) evaluation of myocardial infarction size can be obtained by CTn I concentration as early as the ninth hour.     

False lumen patency as a predictor of late outcome in aortic dissection

Aortic dissection (AD) is a disease with a high-risk of mortality. Late deaths are often related to complications in nonoperated aortic segments. Between 1984 and 1996, we retrospectively analyzed the data of 109 patients with acute AD (81 men and 28 women; average age 61 ± 14 years). All imaging examinations were reviewed, and a magnetic resonance imaging examination was performed at the time of the study. Aortic diameters were measured on each aortic segment. Predictive factors of mortality were determined by Cox’s proportional hazard model, in univariate and multivariate analyses, using BMDP statistical software. Follow-up was an average of 44 ± 46 months (range 24 to 164). Actuarial survival rates were 52%, 46%, and 37% at 1, 5, and 10 years, respectively, for type A AD versus 76%, 72%, and 46% for type B AD. Predictors of late mortality were age >70 years and postoperative false lumen patency of the thoracic descending aorta (RR 3.4, 95% confidence intervals 1.20 to 9.8). Descending aorta diameter was larger when false lumen was patent (31 vs 44 mm; P = 0.02) in type A AD. Furthermore, patency was less frequent in operated type A AD when surgery had been extended to the aortic arch. Thus, patency of descending aorta false lumen is responsible for progressive aortic dilation. In type A AD, open distal repair makes it possible to check the aortic arch and replace it when necessary, decreases the false lumen patency rate, and improves late survival.     

Preoperative quality of life as a predictive factor of 3-year survival after open heart operations

BACKGROUND: The aim of this prospective study was twofold: to determine the evolution of quality of life in heart surgery patients through the first 3 postoperative years using the Nottingham Health Profile questionnaire and to determine whether preoperative quality of life influences 3-year survival. METHODS: From January to July 1994, 215 patients underwent elective open heart operation in our department. Patients filled in the Nottingham Health Profile questionnaire five times: preoperatively, postoperatively at month 3, and at each anniversary of their operation for 3 years. The evolution of quality of life scores through time were compared using analysis of covariance with repeated measures. Analysis of 3-year survival prognostic factors was achieved using the Cox proportional hazards model. RESULTS: Quality of life scores varied through time, but not significantly. Multivariate analysis showed two independent risk factors to influence 3-year survival: dyspnea class (III-IV versus I-II, relative risk = 2.80, 95% confidence interval = 1.2 to 6.5) and the energy section of the Nottingham Health Profile questionnaire (relative risk = 1.02 by unit, 95% confidence interval = 1.01 to 1.03). CONCLUSIONS: Our study shows quality of life scores to be stable for the first 3 years after operation and the preoperative energy score to be predictive of 3-year survival.     

Effects of nitric oxide on cardioprotection prior to ischemia-reperfusion

This study aimed at evaluating the role of nitric oxide (NO) when generated 24 h prior to ischemia-reperfusion. Three groups were studied in an isolated buffer-perfused heart model: Control (saline = 3.3 mL/kg, n = 10), the precursor of NO, L-arginine, (500 mg/kg, n = 10) and an inhibitor of NO synthase, L-NAME, (10 mg/kg, n = 9). All groups were injected intraperitoneally 24 h before heart extraction. Nitrites, nitrates (an index of nitric oxide release) and cardiac troponine I were assayed. During the reperfusion period, there was a low release of nitric oxide and cardiac troponine I associated with improved recovery of post-ischemic myocardial function. These results indicate that in this model, the pre-treatment improved myocardial function and thus, NO could play a role as a trigger and not as a mediator of cardioprotection.     

Warm and tepid cardioplegia: do they provide equal myocardial protection?

BACKGROUND: Cardiac troponin I (CTnI) has been shown to be a marker of myocardial injury. The aim of this prospective, randomized study was to compare intermittent antegrade warm cardioplegia with tepid blood cardioplegia in patients undergoing first elective coronary artery bypass graft, using CTnI release as the criterion for evaluating the adequacy of myocardial protection. METHODS: Seventy patients were randomly assigned to one of two cardioplegia groups. CTnI concentrations were measured in serial venous blood samples drawn immediately before cardiopulmonary bypass and after aortic unclamping at 6, 9, 12, and 24 hours. Analysis of covariance with repeated measures was performed to test the effect of the type of cardioplegia and time on CTnI concentration. RESULTS: The total amount of CTnI released (8.23 +/- 20.5 microg in the warm group and 3.19 +/- 2.4 microg in the tepid group) was not statistically different (p = 0.23). The CTnI concentration did not differ for any sample in either of the two groups when adjusted on ejection fraction and the number of preoperative myocardial infarctions (p = 0.06). No patient in the tepid group versus 4 patients in the warm group showed CTnI evidence of perioperative myocardial infarction (p = 0.12). CONCLUSIONS: Our study showed no preference for warm or tepid cardioplegia in terms of myocardial protection, either for clinical or biological data.     

Usefulness of procalcitonin in the early detection of infection after thoracic surgery

Objective: The twofold aim of this prospective clinical study was to assess the accuracy of procalcitonin as a marker of postoperative infection after thoracic surgery and to compare it with C-reactive protein. Methods: Procalcitonin and C-reactive protein concentrations, clinical symptoms of infection and systemic inflammation were recorded preoperatively and 5 days postoperatively in 157 patients undergoing the following procedures: 52 wedge resections, 28 pneumonectomies and 77 lobectomies (or bilobectomies). Patients were classified as non-infected or infected according to predefined criteria. Results: In non-infected patients (n=132), procalcitonin peaked on day 1 and C-reactive protein, on day 2. The procalcitonin value was significantly higher in patients having undergone a pneumonectomy (0.73±0.78 versus 0.54±0.25 ng/mL for lobectomy and 0.50±0.35 ng/mL for wedge resection; P=0.04). The mean value of procalcitonin was significantly higher in patients with postoperative infection (n=25) than in those with no postoperative infection (3.6±5.5 versus 0.63±0.62 ng/mL; P=0.0001). The onset of infection most frequently occurred on postoperative day 2 (43% of patients); maximum procalcitonin and C-reactive protein concentrations most frequently appeared on postoperative day 1 (56% of patients) and day 2 (63% of patients), respectively. The best cutoff value for detection of infection with procalcitonin was 1 ng/mL and with C-reactive protein, 100 mg/L. Comparing the area under the Receiver Operating Characteristic curves, procalcitonin was better than C-reactive protein for detecting postoperative infection (0.92 versus 0.66; P<0.0001). Conclusions: Procalcitonin can be used as a reliable diagnostic parameter to detect and to monitor infectious complications in the postoperative period after thoracic surgery, especially in patients felt to be at higher risk (SIRS). It provides more information about the course of the disease than C-reactive protein does, and can be detected before the occurrence of clinical infection.