patients with early onset coronary artery disease ( cad ) are a special subgroup of atherosclerotic patients and account for 4% to 10% of all cad patients . young and old cad patients show different risk factor profiles , clinical presentation , coronary lesion distribution and prognosis 1 . however , the relatively small number of young cad patients has hindered attempts to understand the factors associated with long - term outcome of this population . percutaneous coronary intervention ( pci ) has become an important strategy for treating cad , even for high - risk lesions , such as three - vessel disease and left main coronary disease 2 . recently , several clinical trials have shown the efficacy of pci in early - onset cad . pci in young adults has shown excellent results on follow - up and is considered the treatment of choice 3 - 5 . drug - eluting stents have been widely used in pci because of their significant reduction in target vessel revascularization as compared with bare - metal stents 6 . however , few studies have examined the prognosis of drug - eluting stenting in relatively young cad patients . in this study , we performed a study to examine risk factors associated with adverse cardiovascular events after drug - eluting stent implantation in patients with early - onset cad . we selected consecutive patients < 50 years old who underwent drug - eluting stent implantation from january 2008 to december 2011 in qilu hospital , shandong university . exclusion criteria were history of familial dyslipidemia , type i diabetes , or endstage renal disease . age- and gender - matched subjects angiographically proven to be disease free were selected as normal controls . the study was approved by the local review board and ethics committee , and all patients gave their written informed consent . both patients and controls came from the same geographical area and had similar socioeconomic and ethnic backgrounds . a family history of cad was defined as the presence of at least one - first degree relative with cad developing before age 55 years for men and 65 years for women . the body mass index ( bmi ) diabetes was defined as a fasting serum glucose level > 126 mg / dl or current use of any diabetes medication . hypertension was defined as seated diastolic blood pressure > 90 mmhg , systolic blood pressure > 140 mmhg , or use of anti - hypertensive drugs . current smokers or drinkers were defined by self - reported current smoking or regular drinking . cad extent was assessed in 2 ways as previously described7 : 1 ) number of major coronary vessels with > 70% occlusion ( left anterior descending , left circumflex , and right coronary arteries ) , namely , single- , double- , or triple - vessel disease , classified as grades 1 - 3 ( > 50% lesion in the left main coronary artery was considered as two - vessel disease ) ; and 2 ) number of narrowed major coronary vessels ( left main , left anterior descending , left circumflex , and right coronary arteries ) and/or their second - order branches ( up to 2 large diagonals , 2 large marginals , and the posterior descending artery ) with any narrowing , classified as grades 0 - 9 . the follow - up information regarding health status and any hospital admissions was obtained from hospital records and by telephone in june 2012 . the primary endpoint was the occurrence of major adverse cardiovascular events ( maces ) , including death ( noncardiacvascular death and cardiac death ) , myocardial infarction , stroke , and any revascularization ( pci or coronary artery bypass grafting ) . cardiovascular death was defined as death due to myocardial infarction , stroke or sudden death without any obvious reasons . target lesion revascularization was defined as any attempted percutaneous or surgical revascularization of lesions in the coronary artery after the initial procedure . outcomes were assessed by 2 independent observers who were blinded to patient baseline , clinical , and laboratory data . analysis of normality of continuous variables involved the kolmogorov - smirnov test . normally distributed continuous variables are described by meansd . non - normally distributed variables are described by median ( interquartile range ) . differences among groups were analyzed by t test or mann - whitney u test for continuous variables and chi - square or fisher 's exact test for categorical data . cox proportional - hazards multiple regression analysis involved potential confounders associated with clinical outcome with p - value < 0.2 included in the model . we selected consecutive patients < 50 years old who underwent drug - eluting stent implantation from january 2008 to december 2011 in qilu hospital , shandong university . exclusion criteria were history of familial dyslipidemia , type i diabetes , or endstage renal disease . age- and gender - matched subjects angiographically proven to be disease free were selected as normal controls . the study was approved by the local review board and ethics committee , and all patients gave their written informed consent . both patients and controls came from the same geographical area and had similar socioeconomic and ethnic backgrounds . a family history of cad was defined as the presence of at least one - first degree relative with cad developing before age 55 years for men and 65 years for women . the body mass index ( bmi ) diabetes was defined as a fasting serum glucose level > 126 mg / dl or current use of any diabetes medication . hypertension was defined as seated diastolic blood pressure > 90 mmhg , systolic blood pressure > 140 mmhg , or use of anti - hypertensive drugs . current smokers or drinkers were defined by self - reported current smoking or regular drinking . cad extent was assessed in 2 ways as previously described7 : 1 ) number of major coronary vessels with > 70% occlusion ( left anterior descending , left circumflex , and right coronary arteries ) , namely , single- , double- , or triple - vessel disease , classified as grades 1 - 3 ( > 50% lesion in the left main coronary artery was considered as two - vessel disease ) ; and 2 ) number of narrowed major coronary vessels ( left main , left anterior descending , left circumflex , and right coronary arteries ) and/or their second - order branches ( up to 2 large diagonals , 2 large marginals , and the posterior descending artery ) with any narrowing , classified as grades 0 - 9 . the follow - up information regarding health status and any hospital admissions was obtained from hospital records and by telephone in june 2012 . the primary endpoint was the occurrence of major adverse cardiovascular events ( maces ) , including death ( noncardiacvascular death and cardiac death ) , myocardial infarction , stroke , and any revascularization ( pci or coronary artery bypass grafting ) . cardiovascular death was defined as death due to myocardial infarction , stroke or sudden death without any obvious reasons . target lesion revascularization was defined as any attempted percutaneous or surgical revascularization of lesions in the coronary artery after the initial procedure . outcomes were assessed by 2 independent observers who were blinded to patient baseline , clinical , and laboratory data . analysis of normality of continuous variables involved the kolmogorov - smirnov test . normally distributed continuous variables are described by meansd . non - normally distributed variables are described by median ( interquartile range ) . differences among groups were analyzed by t test or mann - whitney u test for continuous variables and chi - square or fisher 's exact test for categorical data . cox proportional - hazards multiple regression analysis involved potential confounders associated with clinical outcome with p - value < 0.2 included in the model . from january 2008 to december 2011 , 3625 patients had underwent drug - eluting stent implantation in qilu hospital , shandong university . we finally recruited 437 patients with > 70% stenosis in at least 1 coronary vessel on angiography as early - onset cad patients ; the patients had been implanted with drug - eluting stents . we recruited 132 age- and gender - matched subjects angiographically proven to be disease free as normal controls . similar to previous reports 9 , 10 , most cases were male ( 90.3% ) . as compared with controls , cases had higher bmi and rate of smoking , family history of cad , diabetes and hypercholesterolemia ( p<0.05 ) . in contrast , the groups did not differ in history of hypertension or rate of drinking ( p>0.05 ) . the average number of risk factors ( including smoking , family history , hypercholesterolemia , hypertension and diabetes ) was 2.00 0.05 for cases and 1.39  0.09 for controls ( p<0.001 ) . the most common clinical presentation was unstable angina ( 55.8% ) , followed by st - segment elevation mi ( 39.4% ) and non - st - segment elevation mi ( 4.8% ) . one patient had a previous diagnosis of renal failure and 2 patients had heart failure . five patients ( 1.1% ) had a previous diagnosis of autoimmune or rheumatic diseases ; 21 had a history of myocardial infarction and 6 of these had undergone pci . single - vessel disease was present in 42.1% of all cases , followed by double - vessel disease ( 29.8% , table 3 ) . bifurcation lesions were found in 59 patients ( 13.5% ) . in all , 314 patients had 1 to 2 stents implanted , 108 had 3 to 4 , and 15 had more than 4 . the mean stent length for cases was 50.21 1.50 mm . glycoprotein iib / iiia inhibitors were used in 27.7% of patients undergoing pci . at discharge , almost all patients were prescribed aspirin , clopidogrel and statins ( 91.2% ) . -blockers , angiotensin - converting enzyme inhibitors , and angiotensin receptor blockers were prescribed for 81.3% , 39.2% , and 23.3% of patients , respectively . the incidence of in - hospital and long - term adverse events are in table 4 . during the hospital stay , 5 patients experienced myocardial infarction . 1 patient died and 4 other patients underwent repeat pci . the incidence of in - hospital maces was 1.1% . during a median follow - up of 24 months ( interquartile range 14 - 34 months ) , the overall mortality was 0.7% ( 2 patients died from cardiac causes and 1 patient from liver cancer ) , and the incidence of myocardial infarction was 3.9% . repeat pci was needed in 9.4% of patients ( n=41 ) and coronary artery bypass grafting in 0.5% ( n=2 ) . proportional - hazards multivariate analysis , family history of cad and diabetes were independent predictors of maces with drug - eluting stenting for cad ( hr 2.61 , 95% confidence interval 1.29 - 4.00 , p = 0.002 ; and hr 2.48 , 95% confidence interval 0.86 - 3.14 , p = 0.004 , respectively ; table 5 ) , after adjusting for age , gender , cad extent , smoking status , bmi , hypertension and hypercholesterolemia at baseline . early - onset cad requires special clinical attention because of its devastating impact on patients and society . recently , pci has shown encouraging results in relatively young people with cad 4 , 5 , but data on drug - eluting stenting in this subset are limited . most available published studies were conducted in the era before such stenting or examined both drug - eluting and bare - metal stenting . in this study , we performed long - term follow - up ( median 24 months ) of relatively young patients ( < 50 years old ) with cad and revealed that drug - eluting stenting was a reliable treatment for early - onset cad . family history of cad and diabetes were independent risk factors of adverse cardiovascular events in early - onset cad with stent implantation . drug - eluting stenting is gaining in popularity among cardiologists because of its effectiveness in reducing restenosis rate . pci seems to provide excellent results in the hospital and during long - term follow - up 11 , 12 . recently , drug - eluting stenting showed good short - term follow - up results in 26 patients with premature cad , with no target lesion revascularization 3 . in our study , after a median follow - up of 24 months ( interquartile range 14 - 34 months ) , the overall mortality was 0.7% and the incidence of total maces was 12.4% . these rates are relative lower than those in studies of ordinary populations 13 , 14 . thus , drug - eluting stenting could be a good choice for therapy for early - onset cad . family history of cad is an important risk factor of early - onset cad 1 , 15 , but little has been learned about the relationship between family history and prognosis for this subgroup of patients . the results of our study demonstrate that family history of cad is an important predictor of major adverse cardiovascular events in relatively young cad patients with drug - eluting stents . genetic background may play an important role in the development of cad and may be associated with long - term outcomes in relatively young cad patients with drug - eluting stenting , as was shown in unrestricted populations 16 , 17 . diabetes has been considered a risk factor of both early- and late - onset cad 18 . recently , diabetes was found an independent predictor of long - term mortality in premature cad with pci 4 , but studies revealing the relationship between diabetes and outcomes of drug - eluting stenting in early onset cad are lacking . in our study , after a median follow - up of 24 months , diabetes was found a strong risk factor of major cardiovascular events after drug - eluting stenting , which indicates the importance of diabetes control . recently , several large - scale studies have shown a strong association of traditional risk factors ( such as male sex , family history , diabetes , dyslipidemia , and smoking ) and early - onset cad 19 , 20 . our study confirmed those previous finding by showing a significantly higher rate of smoking , family history of cad , diabetes , and hypercholesterolemia in relatively young patients with cad . the average number of risk factors was also significantly greater in patients than controls , which implies the importance of traditional risk factors in the development of early - onset cad . gender and smoking should be monitored because of a high difference between patients and controls in these factors . a much larger sample size would be needed to have necessary power for a more robust death / mi endpoint . secondly , although we showed the overt association of family history of cad and diabetes with long - term outcomes of drug - eluting stenting , the sample was from a single center , so results may not be representative of the general population . the conclusion needs to be examined in a larger population and a better - designed study . in conclusion , our study showed that drug - eluting stenting is a reliable treatment for chinese patients with early onset cad . family history of cad and diabetes are independent risk factors of adverse cardiovascular events in early onset cad with such stenting .
objective we lack data on the long - term outcome of drug - eluting stenting in patients with early - onset coronary artery disease ( cad ) . here , we investigated the association of traditional risk factors and major adverse cardiovascular events ( maces ) after drug - eluting stenting in patients with cad who were < 50 years old . 
 methods we enrolled 437 consecutive cad patients < 50 years old who underwent drug - eluting stenting and 132 subjects who were age- and sex - matched and angiographically shown to be disease free as controls . 
 maces were analyzed in cad patients for a median of 24 months [ interquartile range 14 - 34 months ] . 
 results male patients accounted for 90.4% of cases . as compared with controls , patients with early - onset cad had higher body mass index and rates of smoking , family history of cad , and diabetes and hypercholesterolemia . during the hospital 
 stay , 1 patient died , and the incidence of maces was 1.1% . at the end of follow - up , the overall death rate was 0.7% . 
 maces were observed in 54 patients ( 12.4% ) . on cox proportional hazard analyses , positive family history and diabetes were independent risk factors of maces ( hr 2.61 , 95% confidence interval 1.29 - 4.00 , p = 0.002 ; and hr 2.48 , 95% confidence interval 0.86 - 3.14 , p = 0.004 , respectively ) . 
 conclusions drug - eluting stenting is a reliable treatment for patients with early - onset cad 
 . positive family history of cad and diabetes are independent risk factors of adverse cardiovascular events in this subgroup of patients after drug - eluting stent implantation .