ABSTRACT
Objective Perioperative myocardial infarction remains a severe complication in non-cardiac surgery and is one of the major causes of death.Cardiac troponin (cTn) Ⅰ elevation is associated with short-term and long-term mortality.The aim of the study was to assess the proportion rate of cTnⅠ elevation and its clinical characteristics among patients admitted for orthopaedic surgery with or without cardiovascular events.Methods This is a retrospective study including 27 744 patients aged 50 years or older who admitted for orthopaedic surgery from 2009-2015 in Beijing Jishuitan Hospital.Results Two hundred and sixty-five patients [age (71.7±9.9) years] had cTnⅠ level＞ 0.04 μg/L with 66％ (175 patients) of them being female.Among them,59 patients were isolated troponin rise (ITR) (n=59),13 were preoperative acute myocardial infarction (AMI),and 193 were postoperative AMI.The proportion of postoperative AMI was 0.69％.Those patients were more likely to have a history of coronary artery disease or hypertension.Non-ST-segment elevation myocardial infarction (NSTEMI) was more common (93.3％) than ST-segment elevation myocardial infarction in these patients.Most of them did not experience ischemic symptoms.Totally 76.7％ of the AMI occurred within 3 days of surgery;and the in-hospital mortality rate was 10.4％.Conclusions Perioperative elevation of troponin is common in patients undergoing orthopaedic surgery.Most postoperative AMI were NSTEMI and with absent or atypical ischemia symptoms.Monitoring troponin levels and electrocardiograph in at-risk patients is needed to find most of the AMI.
ABSTRACT
Objective: To explore the effect of apelin on angiotensin II (Ang II)-induced cardiomyocyte hypertrophy and intracellular signal transduction mechanism in experimental rats. Methods: The cardiomyocyte from 1 to 3 days neonatal rats were cultured with Ang II to induce the cardiomyocyte hypertrophy, and the cells were treated by apelin at different concentrations. The [3H] Leucine incorporation, cardiomyocyte surface area and total protein expression were analyzed to evaluate the degree of cardiomycyte hypertrophy. The protein expressions of intracellular BNP, β-MHC, nuclear factor 3 of activated T cells (NFATc3), calcineurin, phospho-calcineurin, calmodulin kinase II (CaMK II) and phospho-CaMK II were assessed by Western blot analysis. The mRNA expressions of BNP andβ-MHC were examined by RT-PCR. Results: Apelin may inhibit Ang II induced cardiomyocyte hypertrophic response in a dose-dependent manner, the maximum inhibition was achieved at Ang II 1000 nmol/L. Meanwhile, apelin may inhibit Ang II-induced elevations of intracellular resting free calcium level, mRNA expressions of BNP andβ-MHC, protein expressions of NFATc3, phospho-calcineurin, CaMK II and phospho-CaMK II in a dose-dependent manner. Conclusion: Apelin may inhibit Ang II-induced cardiomyocyte hypertrophy in experimental rats which might be related to Ca2+-dependent calcineurin signal pass ways.