Positive influence of aspirin on coronary endothelial function: Importance of the dose

Table 1 Characteristics of the patients (mean ± SE) n (%)

	Group I	Group II	P value
	(n = 63)	(n = 76)
Age	60 ± 1	59 ± 1	NS
Men/women	40/23	46/30	NS
Body mass index (kg/m2)	24.6 ± 0.3	24.2 ± 0.3	NS
Coronary risk factors
Smoking (%)	22 (35)	19 (25)	NS
Hypertension (%)	29 (46)	29 (38)	NS
Hypercholesterolemia (%)	23 (37)	30 (39)	NS
Diabetes mellitus (%)	9 (14)	6 (8)	NS
Medications
Statins (%)	11 (17)	13 (17)	NS
ACI and/or ARB (%)	8 (13)	11 (14)	NS
LV ejection fraction (%)	70 ± 1	71 ± 1	NS

ACI: Angiotensin-converting enzyme inhibitor; ARB: Angiotensin II receptor blocker; LV: Left ventricular; NS: Not significant.

Table 2 Biochemical parameters (mean ± SE)

	Group I	Group II	p value
Total cholesterol (mg/dL)	210 ± 5	206 ± 5	NS
Triglyceride (mg/dL)	155 ± 10	144 ± 9	NS
HDL-cholesterol (mg/dL)	54 ± 2	52 ± 2	NS
LDL-cholesterol (mg/dL)	125 ± 5	125 ± 4	NS
Fasting blood sugar (mg/dL)	100 ± 2	98 ± 2	NS
Hemoglobin A1C (%)	5.5 ± 0.1	5.4 ± 0.1	NS
C-reactive protein (mg/L)	1.4 ± 0.4	2.1 ± 0.4	NS
Fibrinogen (mg/dL)	340 ± 21	350 ± 22	NS

HDL: High-density lipoprotein; LDL: Low-density lipoprotein; NS: Not significant.

Table 3 Hemodynamics and angiographic results between groups I and II (mean ± SE)

	Group I	Group II	P value
Baseline mean BP(mmHg)	107 ± 2	104 ± 1	NS
Baseline heart rate (/min)	66 ± 1	67 ± 1	NS
Coronary diameter
Baseline (mm)	3.22 ± 0.07	3.07 ± 0.06	NS
ACh at 3 μg/min (mm)	3.28 ± 0.07	3.07 ± 0.07	NS
(% change)	1.8 ± 0.9	0.1 ± 0.8	NS
ACh at 30 μg/min (mm)	3.26 ± 0.08	2.95 ± 0.07	0.0030
(% change)	1.2 ± 1.1	-3.9 ± 1.0	0.0008
Nitroglycerin (mm)	3.67 ± 0.07	3.51 ± 0.07	NS
(% change)	14.0 ± 1.1	15.1 ± 1.0	NS
Coronary blood flow
Baseline (mL/min)	88.1 ± 3.7	81.9 ± 3.3	NS
ACh at 3 μg/min (mL/min)	131.3 ± 7.8	123.3 ± 7.1	NS
(% change)	50.0 ± 6.3	52.1 ± 5.7	NS
ACh at 30 μg/min (mm)	219.9 ± 21.4	194.8 ± 19.5	NS
(% change)	172.8 ± 33.2	142.6 ± 30.3	NS
Coronary flow reserve	3.4 ± 0.2	3.4 ± 0.1	NS

BP: Blood pressure; ACh: Acetylcholine; NS: Not significant.

Table 4 Hemodynamics and angiographic results between groups Ia and Ib (mean ± SE)

	Group Ia	Group Ib	P value
	(n =50)	(n = 13)
Baseline mean BP (mmHg)	108 ± 2	105 ± 3	NS
Baseline heart rate (/min)	67 ± 2	65 ± 3	NS
Coronary diameter
Baseline (mm)	3.23 ± 0.08	3.14 ± 0.16	NS
ACh at 3 μg/min (mm)	3.32 ± 0.08	3.05 ± 0.17	NS
(% change)	2.4 ± 0.9	-0.6 ± 1.8	NS
ACh at 30 μg/min (mm)	3.32 ± 0.08	3.05 ± 0.17	NS
(% change)	2.6 ± 1.1	-3.8 ± 2.9	0.0123
Nitroglycerin (mm)	3.67 ± 0.08	3.65 ± 0.16	NS
(% change)	13.6 ± 1.1	15.4 ± 2.2	NS
Coronary blood flow
Baseline (mL/min)	91.0 ± 4.6	76.8 ± 9.1	NS
ACh at 3 μg/min (mL/min)	137.7 ± 9.5	106.8 ± 18.7	NS
(% change)	53.4 ± 6.8	37.0 ± 13.4	NS
ACh at 30 μg/min (mm)	195.2 ± 15.9	188.6 ± 31.1	NS
(% change)	125.3 ± 16.2	141.9 ± 31.7	NS
Coronary flow reserve	3.4 ± 0.2	3.7 ± 0.3	NS

BP: Blood pressure; ACh: Acetylcholine; NS: Not significant.

Table 5 Multivariate analysis of variables influencing %change in coronary diameter induced by acetylcholine infusion

Variables	%change in coronary diameter
	induced by ACh 30 mg/min
	t value	P value
Taking aspirin
(+) at the low dose	3.61	0.0004
(-)	-2.09	0.0387
Nitroglycerin-induced dilation	2.71	0.0077
%increase in CBF at ACh 3 mg/min	2.14	0.0344
Mean blood pressure at baseline	1.79	0.0765

r² = 0.212. ACh: Acetylcholine; CBF: Coronary blood flow.