unaware of the reperfusion status of the patients or other clinical data. The admission ECG was considered as a reference for calculating the ST-segment elevation resolution. When more than one ECG was performed upon admission, the ECG with the highest ST-segment elevation was chosen. ST-segment elevation <0,1>60% of the initial value was defined as nonimproved ST-segment or no ST-segment resolution.

Echocardiographic Wall Motion Score Index

Assessment of echocardiographic wall motion score index (WMSI) by two dimensional echocardiography was performed before and 1 month after angioplasty. The left ventricle was divided into 16 segments. Wall motion in each segment was evaluated as follows: 1, normal; 2, hypokinetic; 3, akinetic; 4, paradoxical movement; 5, ventricular aneurysm. WMSI was calculated as the mean score of the segments showing asynergy at baseline, and improvement of wall motion was calculated as the change in WMSI (∆WMSI = WMSI before PCI - WMSI 1 month after PCI).

Statistical Analysis

Continuous variables were expressed as means ± standard deviation (x ± s) and compared by t test. Categofical data were expressed as percentages and com­pared with x2 or Fisher's exact probabilities test. Univariate linear regression analysis was used to assess the correlation between CTFC and ∆WMSI. A P value <0.05 was considered significant.

RESULTS

Baseline Characteristics

Of the 63 patients constituted our study population, coronary stents were implanted in 14 patients in the CTFC slow group and in 23 patients in the CTFC fast group and did not influence the analysis of CTFC. There were no significant differences between the two groups with regard to age, sex, presence of angio­graphically visible collaterals, and coronary risk factors. The blood pressure and heart rate on admission were also similar in both groups, However, patients in the CTFC slow group had a more prolonged elapsed time from the onset of symptoms to perfusion (P <0,05). The basic characteristics are shown in the Table 1.
TABLE I. Baseline Characteristicsª


CTFC slow

CTFC fast



group (n = 24)

group (n = 39)

Age (years)

60 ± 10

59 ± 12

Men (%)

18/24(75.0)

27/39 (69.2)

Mean BP (mm Hg)

108 ± 20

106 ± 22

Heart rate (beats/min)

76 ± 15

75 ± 16

Hipertension (%}

10/24(41.7)

6/39 ( 4 1.0)

Diabetes mellitas (%)

10/24 (41.7)

14/39 (35..9)

Criminal lesión





LAD

11

21

RCA

9

15

LCX

4

3

Single- vessel disease (%)

17/24 (70.8)

27/39 (69.2)

Stent (%)

14/24 (58,3)

23/39 (59.0)

Collateral (grade ≥ 2) (%)

4/24(16.7)

8/39 (20.5)

Elapsed time (hr)

5.8 ± 2.4*

4.5 ± 2.1

TIMI before PCI (0/1/2)

18/3/3

21/10/8

CTFC (frames)

31,9 ± 4.5*

17.4 ± 4.2


aThere were no significant differences between the two groups with regard to age, sex. presence of angiographically visible collaterals, blood pressure, and heart rate. However, patients in the CTFC slow group had a more prolonged elapsed time. Compared with CTFC fast group *P < 0.05. BP, blood pressure; CTFC, corrected TIMI frame count; LAD, left anterior descending; LCX, left circumflex; RCA, right coronary artery; TIMI, thrombolysis in myocardial infarction.

CTFC

The mean TIMI frame counts derived from 80 patients at our institution with angiographically normal coronary artery were LAD as follows: 39.4 ± 3.8, LCX: 21.9 ± 2.7, RCA: 22,7 ± 3.0, The CTFC was calculated by dividing left anterior descending artery's TIMI frame counts by 1,7 to normalize for their longer length. The frame rate of a digital cardiac image was calculated as 30 frames per second. The mean CTFC was 23 ± 3 in an angiographically normal coronary artery, which was concordant with a previous study [4]. We defined the CTFC <40 as TIMI grade 3 flow. A cut-off point of 23 was used to divide CTFC fast verse slow. In this study, all patients with successful angioplasty were divided into two groups according to the value of CTFC: 39 patients with CTFC < 23 as the CTFC fast group and 24 patients with 23 ≤ CTFC < 40 as the CTFC slow group. The value of CTFC in the CTFC fast group was 17.4 ± 4.2 and 31.9 ± 4,5 in the CTFC slow group.

The Correlation between ECG ST-Segment Resolution and CTFC

The CTFC fast group had a higher ratio of complete ST resolution than the CTFC slow group (54.1% vs. 25,0%, P <>