Qualitative and quantitative coronary angiography in patients with Q-wave myocardial infarction versus patients with non-Q wave myocardial infarction

ABSTRACT

The classification of myocardial infarction into transmural and subendocardial types has been based on the presence or absence of abnormal Q-waves in the ECG; it is more appropriate to describe myocardial infarction as Q-wave and non-Q wave infarction. Visual evaluation of CA lesions was associated with inter observer and intraobserver variability of about 30%. In the present study 40 patients [20 patients with Q-wave and 20 patients with non Q-wave myocardial infarction] have been assessed for the presence or absence of significant difference regarding all risk factors for CAD, echocardiographic findings, cardiac enzymes and various QCA [Quantitative Coronary Angiography] variables [percentage of stenosis, plaque area, length of lesion, type of lesion, number of vessels affected and site of lesion]. The distribution of risk factors [age. sex, smoking, hypertension, diabetes, hyperlipmdemia] between both groups revealed no statistically significant difference. The history of previous ischemic insult was significantly higher in group II [40% in group II and 5% in group I]. Echocardiographic findings: Regional wall motions abnormalities [RWMA] in group 1, 95% of patients have hypokinesia and 5% have akinesia in one or more left ventricular wall segments. In goup 2, 20% of patients have normal wall motions, 65% have hypokinesia and 15% have akinesia in one or more of left ventricular wall segments [P<0.05]. However the ejection fraction, fractional shortening, end-systolic and end-diastolic volumes were not statistically different between the two groups. In evaluation of cardiac enzymes, CPK; ranged from 550 to 2001 IU, in group I. with a mean value of 997 +/- 425 IU, in group 2, it ranges from 220 to 900 IU with a mean value of 451 +/- 149 IU [P<0.001]- LDH; it ranges from 550 IU tol900 IU with a mean value of 1657 +/- 198 IU while in group 2 it ranges from 301 IU to 860 IU with a mean value of 618 +/- 168 IU [P<0.05]. CPK MB fraction; values were ranging from 28 IU to 60 IU with a mean value of 53 +/- 21.7 IU for group I. In group 2 it ranges from 22 to 30 IU with a mean value of 32.9 +/- 9.1 IU [P<0.001]. As regard the parameters of QCA, Percentage stenosis; in group I, it ranges from 61% to 99.6% with a mean value of 87.66 +/- 12.4. In group 2, it ranges from 59% to 99.9% with a mean value of 90 +/- 14.1%, [P>0.05]. Plaque area; in group 1, it range from 1.09 to 16.8 mm2 with a mean value of 5.15 +/- 2.4 mm2. In group 2 it ranges from 0.33 to 21.66 mm2 with a mean value of 7.12 +/- 6.6 mm2 [P>0.05]. Length of lesion; in group 1, it range from 4.42 to 25.75 mm with a mean value of 16.68 +/- 3.7 mm. In group 2. it ranges from 4.72 to 29.3 mm with a mean value of 17.65 +/- 4.6 mm [P>0.05]. Number of vessels affected; in group 1, 60% of patients have single vessel disease, 20% two-vessel disease and 20% multi-vessel disease. In group 2, 50% of patients have single vessel disease, 25% two-vessel disease and 25% multi-vessel disease [P>0.05]. So we concluded that there is no significant difference between Q-wave and non Q-wave myocardial infarction except in the following points the history of previous myocardiat infarction and ischemia is commoner in non Q-wave myocardial infarction. Regional wall motions abnormalities occur more frequently in patients with Q-wave myocardial infarction. Cardiac enzymes are more elevated in Q-wave myocardial infarction than non Q-wave myocardial infarction. It is clear from the study that the magnitude of myocardial infarction should be judged on the anatomical and functional basis rather than the designation of Q-wave or non Q-wave type of myocardial infarction. It is also apparent that quantitative coronary angiography is an accurate and reproducible method for assessing the coronary artery lesion