PubMed · 8338579
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R G Rinaldi. 1993. Coronary sinus cannulation.. https://doi.org/10.1016/0003-4975(93)90062-m
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BACKGROUND: The best strategy for cardiac risk assessment before high-risk vascular surgery remains controversial. A cardiac risk stratification protocol was evaluated in patients undergoing high-risk vascular surgery. Our investigation paralleled the elaboration of the American College of Cardiology/ American Heart Association (ACC/AHA) Guidelines for Perioperative Cardiovascular Evaluation for Noncardiac Surgery and is highly comparable to the proposed guidelines. METHODS AND RESULTS: A cardiac risk stratification protocol was evaluated prospectively in 203 patients scheduled for aortic surgery. Key points of the study were cardiac mortality/morbidity and cost-effectiveness. Patients were stratified into low (n = 101), intermediate (n = 79), and high (n = 23) cardiac risk after clinical predictors. After stratification, the degree of estimated functional capacity assessed by treadmill exercise and daily living activities and expressed by metabolic equivalents (METs) was critical for further cardiac evaluation. In intermediate-risk patients with an estimated functional capacity < 5 METs and in all high-risk patients, noninvasive cardiac testing and/or subsequent medical care were performed. Noninvasive testing was considered necessary in 41 patients, coronary angiography in 7, and myocardial revascularization in 1. Overall hospital mortality was 3.5%. Cardiac mortality and morbidity were 1% and 12.4%, respectively. CONCLUSIONS: Cardiac risk stratification for high-risk vascular surgery patients, according to a protocol similar to the ACC/AHA Guidelines for Cardiovascular Evaluation for Noncardiac Surgery, demonstrated excellent clinical outcome. This approach appears to be a safe and economical strategy for preoperative cardiac evaluation.
Oxidation of LDL may be of pivotal importance in atherogenesis, but the mechanisms that promote oxidation in vivo remain poorly understood. We have explored the possibility that one pathway involves myeloperoxidase, a heme protein secreted by phagocytes. Myeloperoxidase is the only human enzyme known to generate hypochlorous acid (HOCl), a potent oxidizing agent, at physiological halide concentrations. LDL exposed to the complete myeloperoxidase-H2O2-Cl- system underwent chlorination of its protein tyrosyl residues. Treatment of LDL with reagent HOCl resulted in 3-chlorotyrosine formation, implicating HOCl as an intermediate in the enzymatic reaction pathway. In contrast, 3-chlorotyrosine was undetectable in LDL oxidized by hydroxyl radical, copper, iron, hemin, glucose, peroxynitrite, horseradish peroxidase, lactoperoxidase, or lipoxygenase. These results indicate that 3-chlorotyrosine is a specific marker for LDL oxidation by myeloperoxidase. To address the role of myeloperoxidase in promoting LDL oxidation in vivo, we used stable isotope dilution gas chromatography-mass spectrometry to quantify 3-chlorotyrosine in human aortic tissue and in LDL isolated from atherosclerotic lesions. The level of 3-chlorotyrosine in atherosclerotic tissue obtained during vascular surgery was sixfold higher than that of normal aortic intima. Moreover, the level of 3-chlorotyrosine was 30-fold higher in LDL isolated from atherosclerotic intima compared with circulating LDL. The detection of 3-chlorotyrosine in human atherosclerotic lesions indicates that halogenation reactions catalyzed by the myeloperoxidase system of phagocytes constitute one pathway for protein oxidation in vivo. These findings raise the possibility that the myeloperoxidase-H2O2-Cl- system plays a critical role in converting LDL into an atherogenic form.
To investigate any influence of behavioural states on the pulse waves in the descending aorta, 21 human fetuses were studied in utero in uncomplicated gestation at the age of 36-41 weeks. The fetal behavioural states were identified using two real-time scanners and one cardiotocograph. The aortic waveform data and pulse wave velocity (PWV) were recorded by means of two double phase-locking echo-trackers. The PWV of the fetal aorta was significantly lower in fetal behavioural state (FBS) 2F than in FBS 1F, when the fetus was apnoeic, and was also reduced in both states during fetal breathing. The calculated pulse pressure showed the same trend as the PWV. The fetal aortic end diastolic diameter and the pulse amplitude did not alter, when the two states changed. Our data suggest that the central haemodynamics in term fetuses are independently influenced by their behavioural state as well as by fetal breathing. The study of pulse waves in the fetal aorta should preferably be performed during apnoea in state 1F, when neither gross body movements nor breathing movements disturb the recording.