| BackgroundCoronary atherosclerosis heart disease, abbreviated as coronary artery disease (CAD), is one of the most common heart diseases. It is caused by atherosclerosis, and then results in coronary artery stenosis and/or arterial spasm, insufficient blood supply of corresponding artery region and then cause myocardial ischemia, necrosis, myocardial dysfunction and heart organic disease. While the mortality of coronary artery disease is much lower than before, it is still the primary cause of death and disability of the whole world. The effective treatments for CAD mainly include drug therapy, percutaneous coronary intervention, coronary artery bypass graft and stem cell therapy. Over the last few years, this treatments have achieved great progress, especially in the percutaneous coronary intervention. The percutaneous coronary intervention has been developed in 4 stages:percutaneous transluminal coronary angioplasty stage, bare metal stent stage, drug eluting stent stage and fully bioabsorbable stent stage. Since the inception of drug eluting stent, it contributes much to the coronary artery intervention due to its extraordinary anti-restenosis effect that changnes the structure of revascularization for coronary artery disease, and expands the scope of its indications in treating coronary artery disease. Although drug eluting stent reduces the incidence of restenosis effectively, it may lead to the thrombosis with greater probability comparing to bare mental stent based on the increasing evidence in clinical applications.The worst complication is the stent thrombosis in the various complications caused by coronary intervention. In recent years, the whole incidence of stent thrombosis is between 0.4% and 4.2% according to the research on the incidence of thrombosis of drug eluting stent. In spite of low incidence, stent thrombosis often leads to myocardial infraction, malignant arrhythmia, and even sudden death. Stent thrombosis may cause myocardinal infraction with incidence of 50% to 70%, and the mortality of stent thrombosis is about 20% to 40%.The pathophysiologic mechanism of stent thrombosis is rather complicated and is related to vascular endothelial injury, excessive activation of platelets, activation of coagulation system, hypercoagulable state and slow blood flow according to available researches. The factors leading to these conditions could be generalized in the following five categories:drug factor, patient general conditions and complications factor, stent factor, stent implantation operational factor, artery lesion factor. Among them, patient factor is highly related to acute, late and very late stent thrombosis. Elderly, smoking, low heart’s left ventricular ejection fraction, diabetes, renal failure, acute coronary syndrome, hypercoagulation, systemic inflammatory response and so on. It is claimed that pachyemia, increasing activity of sympathetic nerve and adrenomedullary system caused by stress state could lead to acute or subacute stent thrombosis and systemic inflammatory response can also promote thrombus.Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a sleep disordered breathing that with intermittent complete or incomplete obstruction of upper airway during patient sleeping leads to frequent interim apnea or hypopnea, arterial oxygen saturation decrease discontinuously and arterial blood pressure fluctuation. The symptoms of patients with the disease are fat, stubby neck, pharyngeal stenosis, pharynx congestion, fat tongue, glossocoma. It is shown in polysomnography that the reasons of apnea are mouth and nasal airflow fully or partly vanishing, abdominal breathing action abnormally and paradoxical respiratory. Epidemiological data abroad indicate that OSAHS is the disease with high morbidity and mortality over the last few years. The incidence of OSAHS was 22% in adult male and 8% in adult female. According to some researches, it is confirmed that OSAHS is the independent risk factor in various diseases including hypertension, coronary artery disease, arrhythmia, and stroke.About 20% to 25% OSAHS patients suffer from coronary artery disease at the same time. The main pathophysiological factors of OSAHS include sleep structure damage, pleural pressure abnormally change, chronic intermittent hypoxia. The most fatal factor is the target organ damage caused by long term intermittent hypoxia caused by OSAHS and oxidative stress and inflammation response. Intermittent hypoxia and hypercapnia would result in significant increasing in body sympathetic nervous system activity, enhanced oxidative stress, incidence of systemic inflammation, compensatory hyoerplasia hemoglobin, high blood viscosity, giant capability of platelet adhesion and aggregation,and hyperfunction of the blood coagulation mechanism, decreasing in fibrinolytic activity. All these mediate vascular endothelium damage and then contribute to the formation of coronary unstable plaque and thrombus,and are likely to form embolus in damaged vascular endothelium and atheromatous plaque, even can lead to myocardial infraction.Much small scale research has been conducted on the influence of pathophysiological changes caused by OSAHS chronic intermittent hypoxia on stent implantation efficacy after drug eluting stent implantation to OSAHS patient with coronary artery disease, which is also the focus of public concern. It indicates that OSAHS is the prediction factor of stent restenosis. However, whether it would lead to the stent thrombosis, or is the risk factor of stent thrombosis is not clear yet without much related work.ObjectiveThis research tried to explore the correlation between stent thrombosis and obstructive sleep apnea-hypopnea syndrome after percutaneous intracoronary stent implantation based on retrospective analysis in the stent thrombosis morbidity of patient with coronary artery disease monitored by polysomnography after coronary stent implantation.Subjects and Method1. Research population:Patients monitored by polysomnography after coronary stenting between January 2006 and January 2014. Detailed records of sex, age,blood pressure, blood glucose, blood lipid, cardiac function, renal function and polysomnography results of patients were collected.2. Inclusion criteria:(1) All the implanted stent were drug eluting stent. (2) Released stent attached well after stent implantation showed by coronary angiography without artery dissection and filling defect,TIMI 2-3 level. (3) Patients received DAPT more than one year after stent implantation. (4) Patients took statins to reduce blood lipids and stabilize plaques after stent implantation. (5) Patients received PSG.3. Exclusion criteria:(1) Patients with left ventricular ejection fraction<40%. (2) Patients with serious respiratory dysfunction caused by chronic obstructive pulmonary disease and other diseases, and central or complex sleep apnea syndrome. (3) Patients with renal insufficiency(Cr>130μmol/l). (4)Patients with malignant tumor, giant cell arteritis, Kawasaki disease, antiphospholipid syndrome and other immune system diseases and infectious diseases. (5)Patients with history of radiotherapy and chemotherapy,and patients take glucocorticoid for long term. (6) Patients with cocaine and drug abuse.4. Grouping:There were 117 patients conforming to the inclusion and exclusion criteria above.29 patients whose AHI>5/h were classified as OSAHS group, and 88 patients whose AHI<5/h were classified as non-OSAHS group. Among OSAHS group, there were 26 male patients and 3 female patients with average age of 63±10. Among non-OSAHS group, there were 81 male patients and 7 female patients with average age of 63±7.5. Polysomnography:Used American Sandman sleep monitoring equipment to nocturnal polysomnography all the subjects, with a monitor time about 7 hours to 8 hours. Electroencephalogram, electrocardiogram, electromyogram, electrooculogram, mouth and nasal airflow, thoracoabdominal breathing, and blood oxygen saturation were monitored.6. Definition of OSAHS:According to international criteria, patient with AHI>5/h during sleep was diagnosed as sleep apnea-hypopnea syndrome, and patients without mouth and nasal airflow during sleep apnea while still having thoracoabdominal breathing was diagnosed as obstructive sleep apnea.7. Dual antiplatelet therapy:After implantation patients should have taken Aspirin 0.1 g/d combining with clopidogrel 75mg/d to do the antiplatelet therapy. Patients should have taken these two kinds of medicine at least one year.8. Definition of stent thrombosis:According to Academic Research Consortium, the definition of stent thrombosis was as follows. Explicit stent thrombosis is that thrombus exists at the region of stent implantation and stent edge confirmed by coronary angiography and the patient exists the symptom of myocardial infraction simultaneously. Probable stent thrombosis is that patient dies with unknown reason within 30 days after operation or myocardial infraction happens in the region that controlled by the blood vessel which had stent implanted. Potential stent thrombosis is that unexplained death happens at any time after 30 days of coronary artery stent implantation.9. Statistical approach:Continuous variables were expressed as mean±standard deviation or median (interquarter range) and were compared with Student t test or Mann-Whitney U test.Categorical variables were expressed as frequency and were compared with Chi-square test or Fisher’s exact probability test. All analysis was performed with the use of SPSS software version 13.0 and bilateral comparison method is taken. The difference was significant if P<0.05.Results1. Baseline data:117 patients were recruited,29 patients in OSAHS group and 88 patients in non-OSAHS group. The morbidity of OSAHS was 24.8%,the morbidity of hypertension was 86.3% and the morbidity of abnormal glucose metabolism was 63.2%. There was no notable difference between the two groups in age, sex, blood pressure, blood glucose, ratio of acute coronary syndrome, EF%, Scr,LDL-C. The AHI of OSAHS group21.2 (13.05-39.2) was significantly higher than that of non-OSAHS group2.9 (2.1-3.7) (P<0.001). The lowest SpO2 of OSAHS group83 (75-86.5)% was much lower than the non-OSAHS group90 (89-92)% (P<0.001).The AHI was significantly elevated in patients who suffered stent thrombosis,indicating that these subjects experienced an incresed risk of stent thrombosis(area under ROC curve=0.834,P=0.024).When AHI=13.9/h,the sensitivity and specificity for stent thrombosis were 75% and 83.2%.2. Stent thrombosis morbidity:After retrospective referring to medical records and follow-up, it showed that four patients developde stent thrombosis and the whole morbidity was 3.4%. In the OSAHS group, there were three patients had stent thrombosis,among them, one patient with definite stent thrombosis and other two patients with probable stent thrombosis and the ratio of incidence of stent thrombosis was 10.3%. While in the non-OSAHS group there were only one patient had stent thrombosis and he had definite stent thrombosis and the ratio of incidence of stent thrombosis was only 1.1%. In short, the morbidity of stent thrombosis was much higher in OSAHS group than non-OSAHS group(P=0.047).ConclusionIn conclusion, the CAD patient is more likely to suffer from stent thrombosis with obstructive sleep apnea hypopnea syndrome than those who without obstructive sleep apnea hypopnea syndrome, and obstructive sleep apnea hypopnea syndrome is likely to be the risk factor of stent thrombosis. |
