Table 1

Baseline characteristics of patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) during 2011–2014

	2011		2012		2013		2014		P values for trend
	n	%	n	%	n	%	n	%	P values for trend
ACS	30 800		34 974		39 524		39 361
UAP	22 038	71.6	24 847	71.0	28 727	72.7	28 508	72.4	<0.0001
STEMI	6514	21.1	7302	20.9	7889	20.0	7856	20.0	<0.0001
NSTEMI	2248	7.3	2825	8.1	2908	7.4	2997	7.6	0.87
Age, years	30 651		34 872		39 466		39 351
18–24	12	0.0	8	0.0	16	0.0	15	0.0	0.70
25–34	177	0.6	223	0.6	246	0.6	243	0.6	0.62
35–44	1597	5.2	1930	5.5	2149	5.4	2187	5.6	0.09
45–54	5849	19.1	6663	19.1	7283	18.5	7507	19.1	0.52
55–64	10 291	33.6	11 990	34.4	13 888	35.2	13 381	34.0	0.11
65–74	8615	28.1	9510	27.3	10 650	27.0	10 832	27.5	0.09
75–84	3850	12.6	4227	12.1	4884	12.4	4800	12.2	0.33
>84	260	0.8	321	0.9	350	0.9	386	1.0	0.11
Gender	30 155		34 191		39 189		39 336
Male	22 017	73.0	25 423	74.4	29 104	74.3	29 193	74.2	<0.01
Female	8138	27.0	8768	25.6	10 085	25.7	10 143	25.8
Ethnicity	30 800		34 974		39 524		39 361
Han	30 589	99.3	34 691	99.2	38 974	98.6	38 620	98.1	<0.0001
Others	211	0.7	283	0.8	550	1.4	741	1.9
Region of hospital	30 783		34 970		39 524		39 361
North China	9156	29.7	9631	27.5	9914	25.1	11 086	28.2	<0.0001
Northwest	7632	24.8	7939	22.7	9728	24.6	7821	19.9	<0.0001
Northeast	3924	12.7	5347	15.3	6691	16.9	7284	18.5	<0.0001
East China	3742	12.2	4630	13.2	5053	12.8	5241	13.3	<0.001
Southwest	3515	11.4	4346	12.4	4877	12.3	4549	11.6	0.96
Central China	1977	6.4	1928	5.5	1910	4.8	1944	4.9	<0.0001
South China	837	2.7	1149	3.3	1351	3.4	1436	3.6	<0.0001
Comorbidities	30 800		34 974		39 524		39 361
Hypertension	17 600	57.1	19 942	57.0	21 260	53.8	21 701	55.1	<0.0001
Hyperlipidaemia	6844	22.2	7774	22.2	7420	18.8	7330	18.6	<0.0001
Diabetes mellitus	6829	22.2	7817	22.4	8394	21.2	8819	22.4	0.75
COPD	541	1.8	448	1.3	478	1.2	447	1.1	<0.0001
Current smoking	9093	29.5	10 838	31.0	11 467	29.0	10 568	26.8	<0.0001
Heart failure*	1378	4.5	1373	3.9	1331	3.4	1122	2.9	<0.0001
Renal failure*	277	0.9	297	0.8	259	0.7	276	0.7	<0.001
Under dialysis*	34	0.1	52	0.1	45	0.1	45	0.1	0.71
Prior MI	7560	24.5	7828	22.4	7928	20.1	5648	14.3	<0.0001
Prior CVD	2014	6.5	1912	5.5	1990	5.0	2018	5.1	<0.0001
Prior PVD	457	1.5	430	1.2	489	1.2	515	1.3	0.09
Prior PCI	5702	18.5	6125	17.5	6467	16.4	5973	15.2	<0.0001
Prior CVS	1077	3.5	1192	3.4	563	1.4	14	0.0	<0.0001
Prior CABG	936	3.0	952	2.7	580	1.5	204	0.5	<0.0001
Familial CAD	805	2.6	867	2.5	681	1.7	615	1.6	<0.0001

*Assessed and recorded at admission.
CABG, coronary artery bypass graft; CAD, coronary artery disease; COPD, chronic obstructive pulmonary disease; CVD, cerebrovascular disease; CVS, cardiac valve surgery; MI, myocardial infarction; NSTEMI, non-ST elevation myocardial infarction; PVD, peripheral vascular disease; STEMI, ST elevation myocardial infarction; UAP, unstable angina pectoris.