coronary artery disease is the leading cause of death for both men and women worldwide , and percutaneous coronary intervention ( pci ) has become a frequently performed therapeutic procedure for coronary artery disease since its first application by gruntzig in 1977.1 it has been estimated that over 2 million coronary angioplasty procedures are performed annually around the world.2 women undergoing pci were reported to have a higher risk of adverse outcomes than men,3,4 but most of the studies were performed in the early to mid 1990s . since that time , advances in angioplasty equipment and techniques , combined with oral antiplatelet therapy and glycoprotein iib / iiia inhibitors , have improved outcomes in both men and women . as a result , the sex gap in outcomes after pci has narrowed.5,6 in contemporary practice of interventional cardiology , almost 25% of all pcis are performed in patients aged 75 years and 12% in those aged 80 sex was an independent predictor of overall major adverse coronary events at 30 days , but not of death , and there was no difference in major adverse coronary events between women and men at 12-month follow - up.9 however , the influence of sex on in - hospital and long - term outcomes in very elderly patients ( over 75 years ) has not been reported . in the present study , we compared sex - based in - hospital and long - term outcomes for elderly patients 75 years of age after pci . this prospective cohort study included consecutive patients aged 75 years undergoing pci from january 2005 to december 2010 in the chinese pla general hospital in beijing . the indications for pci included a diagnosis of acute coronary syndrome with no contraindication for pci or serious comorbidities , such as cancer , liver , or respiratory failure , and a diagnosis of stable angina not controlled with standard anti - ischemic pharmacological treatment . the inclusion criteria were : diagnosis of coronary heart disease ; age 75 years ; and an indication for pci . exclusion criteria were : cancer with survival estimated as less than one year ; and serious kidney , liver , or respiratory failure . baseline characteristics , procedures , and in - hospital outcomes were collected in an electronic database . over 45 data elements were selected for analysis , including patient demographic data ( eg , age , sex ) , risk factors ( eg , smoking , diabetes ) , medical history ( eg , number of diseased vessels , prior myocardial infarction [ mi ] , ejection fraction ) , pci indications , clinical setting , and angiographic findings . all pci procedures were performed according to standard clinical guidelines.10 before the procedure , all patients were treated with 300 mg aspirin and 300 mg clopidogrel . qualitative and quantitative coronary angiographies were performed in all patients using standard morphological criteria to characterize baseline lesion characteristics . the endpoint of this study was major adverse coronary and cerebral events , defined as cardiac death , non - fatal mi , target vessel revascularization , and cerebral artery events . hypercholesterolemia was defined as a fasting serum cholesterol level > 5.5 mmol / l or use of lipid - lowering therapy at the time of the procedure . hypertension was defined as blood pressure > 140/90 mmhg or the use of antihypertensive medications . mi was diagnosed by raised creatine kinase mb greater than three times the upper limit of normal . multivessel disease was defined as the presence of > 50% stenosis in two or more major epicardial coronary arteries . target vessel revascularization was defined as repeat revascularization of a lesion in the same epicardial vessel treated in the index procedure . target lesion revascularization was defined as a repeat intervention in the stent or in the 5 mm segments proximal or distal to the stent . procedural success was defined as a minimum reduction in stenosis diameter to less than 20% after pci , with no death , mi , or coronary artery bypass grafting surgery . major bleeding complications were defined as a need for transfusion , a reduction in hemoglobin of more than 40 diabetes mellitus was defined as hyperglycemia , requiring antidiabetic drugs or fasting blood sugar over 126 g / dl . in patients undergoing staged procedures , treated segments from both procedures were grouped together to prevent misclassification . follow - up information for all patients discharged from the hospital was obtained by planned telephone interviews conducted by an experienced data technician . data regarding vital status such as recurrence of angina , acute mi , revascularization , and stroke were collected . in the event of death , the patient s family reported the patient s health status preceding the event , and the death certificate was requested . the medical records in the pla general hospital in beijing were reviewed for all patients who were followed up at this institution , and verification of events occurring at other hospitals was obtained from the attending physicians . routine review and editing of out - of - range data were performed to ensure quality of data received after discharge from hospital . categorical data are presented as percentages and compared using the chi - square or fisher s exact test as appropriate . continuous variables are presented as the mean  standard deviation and compared using the student s t - test or analysis of variance . survival analysis was performed with the kaplan  meier method for each group and compared using the log - rank test . the association between sex and all - cause mortality was determined by multivariable cox proportional hazard regression analyses to adjust for differences in baseline characteristics . potential confounders were entered into models if they were clinically relevant or showed differences between groups in the univariable analysis and p<0.10 . all calculated p - values were two - sided and a p - value < 0.05 was considered to be statistically significant . statistical package for the social sciences version 17.0 software ( spss inc , chicago , il , usa ) was used for all statistical analyses . this prospective cohort study included consecutive patients aged 75 years undergoing pci from january 2005 to december 2010 in the chinese pla general hospital in beijing . the indications for pci included a diagnosis of acute coronary syndrome with no contraindication for pci or serious comorbidities , such as cancer , liver , or respiratory failure , and a diagnosis of stable angina not controlled with standard anti - ischemic pharmacological treatment . the inclusion criteria were : diagnosis of coronary heart disease ; age 75 years ; and an indication for pci . exclusion criteria were : cancer with survival estimated as less than one year ; and serious kidney , liver , or respiratory failure . baseline characteristics , procedures , and in - hospital outcomes were collected in an electronic database . over 45 data elements were selected for analysis , including patient demographic data ( eg , age , sex ) , risk factors ( eg , smoking , diabetes ) , medical history ( eg , number of diseased vessels , prior myocardial infarction [ mi ] , ejection fraction ) , pci indications , clinical setting , and angiographic findings . all pci procedures were performed according to standard clinical guidelines.10 before the procedure , all patients were treated with 300 mg aspirin and 300 mg clopidogrel . qualitative and quantitative coronary angiographies were performed in all patients using standard morphological criteria to characterize baseline lesion characteristics . the endpoint of this study was major adverse coronary and cerebral events , defined as cardiac death , non - fatal mi , target vessel revascularization , and cerebral artery events . hypercholesterolemia was defined as a fasting serum cholesterol level > 5.5 mmol / l or use of lipid - lowering therapy at the time of the procedure . hypertension was defined as blood pressure > 140/90 mmhg or the use of antihypertensive medications . mi was diagnosed by raised creatine kinase mb greater than three times the upper limit of normal . multivessel disease was defined as the presence of > 50% stenosis in two or more major epicardial coronary arteries . target vessel revascularization was defined as repeat revascularization of a lesion in the same epicardial vessel treated in the index procedure . target lesion revascularization was defined as a repeat intervention in the stent or in the 5 mm segments proximal or distal to the stent . procedural success was defined as a minimum reduction in stenosis diameter to less than 20% after pci , with no death , mi , or coronary artery bypass grafting surgery . major bleeding complications were defined as a need for transfusion , a reduction in hemoglobin of more than 40 diabetes mellitus was defined as hyperglycemia , requiring antidiabetic drugs or fasting blood sugar over 126 g / dl . in patients undergoing staged procedures , treated segments from both procedures were grouped together to prevent misclassification . follow - up information for all patients discharged from the hospital was obtained by planned telephone interviews conducted by an experienced data technician . data regarding vital status such as recurrence of angina , acute mi , revascularization , and stroke were collected . in the event of death , the patient s family reported the patient s health status preceding the event , and the death certificate was requested . the medical records in the pla general hospital in beijing were reviewed for all patients who were followed up at this institution , and verification of events occurring at other hospitals was obtained from the attending physicians . routine review and editing of out - of - range data were performed to ensure quality of data received after discharge from hospital . categorical data are presented as percentages and compared using the chi - square or fisher s exact test as appropriate . continuous variables are presented as the mean  standard deviation and compared using the student s t - test or analysis of variance . survival analysis was performed with the kaplan  meier method for each group and compared using the log - rank test . the association between sex and all - cause mortality was determined by multivariable cox proportional hazard regression analyses to adjust for differences in baseline characteristics . potential confounders were entered into models if they were clinically relevant or showed differences between groups in the univariable analysis and p<0.10 . all calculated p - values were two - sided and a p - value < 0.05 was considered to be statistically significant . statistical package for the social sciences version 17.0 software ( spss inc , chicago , il , usa ) was used for all statistical analyses . there were 503 consecutive coronary heart disease patients aged 75 years who underwent pci from january 2005 to december 2010 . of these , 465 ( 92.4% ) who had undergone follow - up were included in this study . there were 303 ( 65.1% ) men and 162 ( 34.9% ) women , with a mean age of 78.53.2 years . the baseline clinical characteristics for the study population according to sex are shown in table 1 . there were no differences between men and women with respect to age , hypertension , diabetes , hyperlipidemia , smoking , chronic bronchial disease , left ventricular ejection fraction , or estimated glomerular filtration rate . men were more likely to have a history of cerebral vascular disease , mi , and bypass surgery . although no significant differences were observed between men and women in unstable angina and non - st elevation mi , men presented more often with st elevation mi but less often with heart failure than women . there were no significant differences in the number of diseased coronary vessels between men and women . the distribution characteristics of lesions were similar in the two groups , except for lesions in the left anterior descending coronary artery , which were more frequent in men ( p=0.037 ) . there were no significant differences between the two groups as to multivessel disease or number and distribution of target vessels . stent placement , including multistents , staged stenting , and number of stents , was almost equal in both sexes . an intra - aortic balloon pump was placed in 3.3% of men compared with 2.5% of women ( p=0.829 ) . the procedural success rate and in - hospital outcomes no significant differences were noted in the rate of complete revascularization among men and women ( 45.2% versus 46.3% , p=0.900 ) . the in - hospital mortality for men and women was 1.3% and 3.1% , respectively ( p=0.335 ) . of the four men who died , three had cardiogenic shock on admission before pci , and one had post - pci cardiogenic shock . of the five women who died , three were in cardiogenic shock on admission before pci , one had retroperitoneal bleeding post - pci , and one had post - pci cardiogenic shock . there was no statistically significant difference in the frequency of emergency bypass surgery , mi , or stroke between men and women . the incidence of major vascular complications and major bleeding did not differ between the groups . the mean follow - up duration was 36.221.8 ( range 678 ) months , with follow - up completed in 92.3% of patients . the mortality at a mean follow - up of 3 years was 12.5% for men and 8.0% for women figure 1a and b show the cumulative overall survival rate and cumulative disease - free survival rate for men and women . the cumulative overall survival rate for men versus women at one , 2 , 3 , 4 , and 5 years of follow - up was 95% versus 94% , 93% versus 93% , 92% versus 87% , 83% versus 89% , and 82% versus 85% , respectively ( figure 1a ) . the cumulative disease - free survival rate for men versus women at one , 2 , 3 , 4 , and 5 years was 94% versus 91% , 88% versus 86% , 81% versus 80% , 78% versus 78% , and 71% versus 70% , respectively ( figure 1b ) . in the 429 patients followed up , there were no significant differences in cumulative overall survival rate ( log - rank test , p=0.159 ) or disease - free survival rate ( log - rank test , p=0.429 ) between men and women . the overall major adverse coronary and cerebral events ( 22.6% versus 20.1% in men and women , respectively , p=0.984 ) , including cardiac death , non - fatal acute mi , target vessel revascularization and cerebral vascular events , showed no significant difference . although both groups showed similar complete revascularization rates , men presented with a significantly higher rate of angina recurrence within 6 months after pci ( 56.3% versus 43.3% , p=0.011 ) . the readmission rate was similar for both sexes ( 29.7% versus 29.3% , p=0.928 ) . multivariable cox proportional hazard regression analyses were used to identify independent predictors of the composite of mortality rate . the variables associated with increased in - hospital or long - term mortality were increasing age , cerebral vascular disease , acute coronary syndrome , previous cardiac history ( including previous mi and previous bypass surgery ) , and angiographic characteristics . the results showed that cerebral vessel disease , heart failure , and multivessel disease are independent predictors for death in patients with acute coronary syndrome . however , sex was not an independent risk factor for in - hospital or long - term mortality after pci . there were 503 consecutive coronary heart disease patients aged 75 years who underwent pci from january 2005 to december 2010 . of these , 465 ( 92.4% ) who had undergone follow - up were included in this study . there were 303 ( 65.1% ) men and 162 ( 34.9% ) women , with a mean age of 78.53.2 years . the baseline clinical characteristics for the study population according to sex are shown in table 1 . there were no differences between men and women with respect to age , hypertension , diabetes , hyperlipidemia , smoking , chronic bronchial disease , left ventricular ejection fraction , or estimated glomerular filtration rate . men were more likely to have a history of cerebral vascular disease , mi , and bypass surgery . although no significant differences were observed between men and women in unstable angina and non - st elevation mi , men presented more often with st elevation mi but less often with heart failure than women . table 2 summarizes the angiographic and procedural characteristics . there were no significant differences in the number of diseased coronary vessels between men and women . the distribution characteristics of lesions were similar in the two groups , except for lesions in the left anterior descending coronary artery , which were more frequent in men ( p=0.037 ) . there were no significant differences between the two groups as to multivessel disease or number and distribution of target vessels . stent placement , including multistents , staged stenting , and number of stents , was almost equal in both sexes . an intra - aortic balloon pump was placed in 3.3% of men compared with 2.5% of women ( p=0.829 ) . no significant differences were noted in the rate of complete revascularization among men and women ( 45.2% versus 46.3% , p=0.900 ) . the in - hospital mortality for men and women was 1.3% and 3.1% , respectively ( p=0.335 ) . of the four men who died , three had cardiogenic shock on admission before pci , and one had post - pci cardiogenic shock . of the five women who died , three were in cardiogenic shock on admission before pci , one had retroperitoneal bleeding post - pci , and one had post - pci cardiogenic shock . there was no statistically significant difference in the frequency of emergency bypass surgery , mi , or stroke between men and women . the incidence of major vascular complications and major bleeding did not differ between the groups . the mean follow - up duration was 36.221.8 ( range 678 ) months , with follow - up completed in 92.3% of patients . the mortality at a mean follow - up of 3 years was 12.5% for men and 8.0% for women figure 1a and b show the cumulative overall survival rate and cumulative disease - free survival rate for men and women . the cumulative overall survival rate for men versus women at one , 2 , 3 , 4 , and 5 years of follow - up was 95% versus 94% , 93% versus 93% , 92% versus 87% , 83% versus 89% , and 82% versus 85% , respectively ( figure 1a ) . the cumulative disease - free survival rate for men versus women at one , 2 , 3 , 4 , and 5 years was 94% versus 91% , 88% versus 86% , 81% versus 80% , 78% versus 78% , and 71% versus 70% , respectively ( figure 1b ) . in the 429 patients followed up , there were no significant differences in cumulative overall survival rate ( log - rank test , p=0.159 ) or disease - free survival rate ( log - rank test , p=0.429 ) between men and women . the overall major adverse coronary and cerebral events ( 22.6% versus 20.1% in men and women , respectively , p=0.984 ) , including cardiac death , non - fatal acute mi , target vessel revascularization and cerebral vascular events , showed no significant difference . although both groups showed similar complete revascularization rates , men presented with a significantly higher rate of angina recurrence within 6 months after pci ( 56.3% versus 43.3% , p=0.011 ) . the readmission rate was similar for both sexes ( 29.7% versus 29.3% , p=0.928 ) . multivariable cox proportional hazard regression analyses were used to identify independent predictors of the composite of mortality rate . the variables associated with increased in - hospital or long - term mortality were increasing age , cerebral vascular disease , acute coronary syndrome , previous cardiac history ( including previous mi and previous bypass surgery ) , and angiographic characteristics . the results showed that cerebral vessel disease , heart failure , and multivessel disease are independent predictors for death in patients with acute coronary syndrome . however , sex was not an independent risk factor for in - hospital or long - term mortality after pci . early studies evaluating sex differences in outcomes of pci overall demonstrated higher complication and adverse outcomes rates in women.3,4 the earlier national heart , lung , and blood institute pci registry indicated female sex to be independently predictive of in - hospital mortality.4 the higher prevalence of adverse outcomes in women was attributed largely to older age , smaller coronary artery diameter , and more prevalent comorbid conditions , including diabetes mellitus , hypertension , hypercholesterolemia , peripheral vascular disease , and heart failure . however , accumulating evidence indicates that there are no differences regarding in - hospital or long - term mortality after pci in elderly women and men.11 in the present study , we compared the sex - based in - hospital and long - term outcomes after pci in patients aged older than 75 years , and demonstrated that , for very elderly patients undergoing pci , men and women have equivalent in - hospital and long - term outcomes , and female is an independent risk factor neither for in - hospital outcomes nor long - term outcomes . an estimated 33% of pcis are performed in women.12 compared with men , women undergoing pci were found to be 5 years older and to have a higher prevalence of hypertension , diabetes , and other comorbidities.13 however , in this study , there was no difference in comorbidities between elderly men and women , which may be related to greater concern over the health status of women in recent years . women in the usa are less likely to have had a history of mi , pci , or coronary bypass graft surgery , which is consistent with our results . in addition , at the time of pci , they have less multivessel disease and are more likely to present with unstable angina . women present with less st elevation mi compared with men , have similar lesion types , less multivessel disease , and better preserved left ventricular function.13 early reports of patients undergoing balloon angioplasty found lower procedural success rates in women . in addition , earlier registry studies showed that women had higher in - hospital mortality after pci , even after adjusting for baseline comorbidities.14 however , recent studies reported similar procedural success rates of more than 90% in both groups.14 with improvements in pci technology and procedures , this study found no differences in procedural success rate , mortality , or complications , including vascular complications and major bleeding ( see table 3 ) . with newer - generation stents and balloons , smaller sheath sizes and catheters , and advances in adjunctive pharmacotherapies , adjusted long - term mortality and morbidity rates after pci have become similar between men and women.14 berger et al studied the effect of sex on long - term mortality in a large cohort of patients undergoing pci . they found that , despite higher - risk characteristics , female sex conferred a long - term survival advantage after pci.13 until now , there have only been a few studies on the very elderly population more than 75 years old.15,16 our study showed that after an average of 3 years of follow - up , mortality was similar for women and men 75 years undergoing pci . after adjustment for baseline characteristics , sex was not associated with the risk of long - term mortality . our study demonstrated significant improvement in long - term outcome after pci in both sexes compared with older studies , and is consistent with recent observations from other centers.17 however , there are several limitations to our study . first , this study was a nonrandomized , retrospective analysis from a single , large - volume , tertiary care center , which limits its generalizability . moreover , it is universally acknowledged that at older ages ( 7090 years ) most patients are female , which is inconsistent with the results of this study where two thirds of patients were male . this may be associated with the fact that female patients are reluctant to accept invasive treatment such as pci . third , the treatment decisions were not randomized and the study population was relatively small , so further large cohort studies are needed . in conclusion , the results of the present study demonstrate that pci has a good success rate and acceptable mortality in patients over 75 years of age . no differences in in - hospital and long - term outcomes were observed between men and women undergoing pci . for elderly patients , sex was not an independent risk factor for in - hospital or long - term mortality after pci .
backgroundthis study aimed to investigate whether there were sex differences in in - hospital and long - term outcomes for elderly patients over 75 years of age undergoing percutaneous coronary intervention for coronary heart disease.methodsconsecutive patients aged 75 years who underwent percutaneous coronary intervention at a single center in the people s republic of china from january 2005 to december 2010 were included in this cohort study . clinical characteristics and in - hospital and long - term outcomes were compared between men and women.resultsa total of 465 patients ( 34.8% women , mean age 78.53.2 years ) were recruited . 
 men had a higher prevalence of st elevation myocardial infarction but were less likely to have heart failure than women ( p<0.05 ) . 
 similar rates of successful in - hospital procedures and deaths were observed in men and women . after a mean follow - up of 3 years , no significant differences were observed between men and women in mortality ( 12.5% versus 8.0% , p=0.151 ) , myocardial infarction ( 1.4% versus 2.7% , p=0.368 ) , target vessel revascularization ( 6.1% versus 4.7% , p=0.540 ) , or cerebral vascular disease ( 7.9% versus 6.0% , p=0.472 ) . 
 cox proportional hazards analysis revealed that sex was not independently associated with either in - hospital mortality or long - term mortality.conclusionin elderly patients over 75 years of age , sex influences the prognosis after percutaneous coronary intervention for coronary heart disease .