Relationship between preinfarction angina and time interval to reperfusion with thrombolytic therapy in acute myocardial infarction

Relationship Between Prodromal Angina Pectoris and Neutrophil-to Lymphocyte Ratio in Patients With ST Elevation Myocardial Infarction

BACKGROUND

The aim of this study was to investigate the relationship between prodromal angina (PA) with neutrophil-to-lymphocyte ratio (NLR) in patients with ST-segment elevation myocardial infarction (STEMI).

METHODS

The study group included 145 patients with STEMI who underwent emergency coronary angiography (CA) within 24hours of symptom onset. Data were collected regarding whether patients had experienced PA before acute myocardial infarction. Seventy-three (73) patients (50.3%) had prodromal angina. Prodromal angina positive and negative groups were compared for demographic characteristics, complete blood count parameters including NLR, blood biochemistry parameters and left ventricular ejection fraction (LVEF).

RESULTS

Neutrophil count, NLR, and troponin I levels were significantly higher in the PA negative group. LVEF after reperfusion and lymphocyte count were lower in the PA negative group. In multivariate regression analysis, NLR (β=-0.419, p<0.001) and LVEF (β=0.418, p<0.001) were found to be significantly associated with the presence of PA in STEMI patients.

CONCLUSIONS

Absence of PA was significantly and independently associated with increased NLR and impaired LVEF after reperfusion, and increased NLR was found as a significant predictor for both lack of PA and impaired LVEF in STEMI patients.

Effect of preinfarction angina pectoris on myocardial blush grade after reperfusion in first anterior wall acute myocardial infarction

BACKGROUND

The aim of the present study was to clarify the effect of preinfarction angina pectoris (PIA) on myocardial blush grade (MBG), a simple marker of myocardial tissue-level reperfusion, in acute myocardial infarction (AMI).

METHODS AND RESULTS

One hundred forty-two patients with first anterior wall AMI who were admitted within 6 h after onset of symptoms were examined. PIA was defined as typical chest pain within 48 h before onset of symptoms. MBG was evaluated by coronary angiography after reperfusion. Patients with MBG 2 or 3 (n=103) had a higher frequency of PIA and a lower frequency of diabetes mellitus than those with MBG 0 or 1 (n=39) (57% vs 28%, p=0.004, and 23% vs 44%, p=0.03, respectively). The former had a lower peak creatine kinase level and a greater left ventricular ejection fraction at predischarge than the latter (3,652+/-2,440 vs 5,507+/-3,058 IU/L, p=0.0002, and 57+/-12% vs 45+/-11%, p<0.0001, respectively). Multivariate logistic regression analysis showed that PIA (p=0.004) and diabetes mellitus (p=0.03) were independently associated with MBG 2 or 3 after reperfusion.

CONCLUSIONS

PIA has beneficial effects on myocardial tissue-level reperfusion evaluated by MBG in first anterior wall AMI.

Effect of preinfarction angina on heart rate variability in the early phase of the first anterior wall acute myocardial infarction

The aim of this study was to clarify the effect of preinfarction angina on heart rate variability (HRV) in anterior wall acute myocardial infarction (AMI). A total of 36 patients experiencing their first anterior wall AMI were prospectively examined. The patients were divided into 2 groups according to the presence (group A, n=24) or absence (group B, n = 12) of preinfarction angina. HRV was assessed on 24-h Holter electrocardiograms recorded on day 3. Peak creatine kinase activity was significantly lower in group A than in group B (2,747+/-1,939 vs 4,891+/-2,639 IU/L, p<0.05). The SD of all RR intervals and ultra-low frequency, very low frequency, and low frequency powers was significantly less reduced in group A than in group B (86+/-24 vs 64+/-22 ms, p<0.05; 2,098+/-1,462 vs 867+/-502 ms2, p<0.01; 1,430+/-1,042 vs 546+/-344ms2, p<0.01; and 354+/-272 vs 186+/-136ms2, p<0.05; respectively). High frequency power, low frequency/high frequency, and pNN50 did not differ significantly between the 2 groups. In conclusion, preinfarction angina has a favorable influence on HRV in the early phase of anterior wall AMI.

Relationship between terminal QRS distortion on the admission electrocardiogram and the time course of left ventricular wall motion in anterior wall acute myocardial infarction

In order to clarify the time course of left ventricular (LV) wall motion in patients with anterior acute myocardial infarction (AMI) showing terminal QRS distortion on the admission electrocardiogram (ECG), the present study examined 106 patients with their first anterior AMI (< or =6 h) who underwent emergency coronary arteriography and cardiac cathetherization at 1 and 6 months after the infarction. The patients were classified into 2 groups according to the presence (group A, n=23) or absence (group B, n=83) of terminal QRS distortion (emergence of the J point at > or =50% of the R-wave amplitude in leads with QR configuration and/or absence of S waves in leads with RS configuration) on the admission ECG. Group A had a lower LV ejection fraction and more reduced regional wall motion (RWM) in the infarct region at both 1 and 6 months after AMI than group B. The degree of improvement in RWM between 1 and 6 months after AMI was less in group A than in group B (-0.1+/-0.5 vs 0.4+/-0.6 SD/chord, p<0.01). This study indicates that patients with anterior AMI showing terminal QRS distortion on the admission ECG have more severely depressed LV wall motion and less improvement in RWM in the infarct region in the healing stage, suggesting that this sign is an indicator of severe myocardial damage.

Evidence for the delayed effect in human ischemic preconditioning: prospective multicenter study for preconditioning in acute myocardial infarction

OBJECTIVES

This study aimed to investigate prospectively the protective effect of a first preinfarction angina attack against acute myocardial infarction (AMI) in human hearts without significant collaterals.

BACKGROUND

Several retrospective studies and the prospective studies have demonstrated the existence of the preconditioning (PC) effect in humans. However, collaterals were not examined in the prospective studies. In animal models, the PC effect on myocardial infarct size appears soon after PC reperfusion (classic) but disappears within 1 to 2 h. It then reappears 24 to 48 h after reperfusion (the delayed PC effect). Meanwhile, the PC effect on stunning appears 12 h after PC reperfusion (the delayed PC effect). The concept of the classic and delayed PC effects has not been investigated in human AMI studies. If the above concept is also correct in humans, the infarct size and/or impairment of the left ventricular function should be inversely correlated with the time interval between the first preinfarction angina attack and the onset of AMI when that time interval is limited to between 2 and 48 h.

METHODS

The subjects were 25 patients with first AMI of the proximal left anterior descending artery who underwent successful direct percutaneous transluminal coronary angioplasty (PTCA) 2 to 6 h after the onset and with no (or poor) collateral circulation (grade 0 or 1). They were divided into two groups: preinfarction angina (PA)(+) group: 11 patients with new onset preinfarction angina from 2 to 48 h before the onset, PA(-) group: 14 patients without angina before infarction. Peak creatine kinase (CK) and cumulative CK were examined, and the left ventricular ejection fraction (LVEF) and the regional wall motion (RWM) were determined from the left ventriculograms during the acute (immediately after the coronary reperfusion) and chronic (four weeks after the onset of AMI) phases. The RWM index (RWMI) was then calculated as the mean motion of chords (standard deviation [SD]/chord) lying in the area of chords of RWM < or = -2 SD in the acute phase (ischemic risk area). RESULTS The increase in the RWMI between the acute and chronic phases was significantly larger in the PA(+) group than in the PA(-) group (1.55 +/- 1.32 and 0.69 +/- 0.75, p < 0.05, respectively) although no significant difference in the enzymatic infarct size was seen between the two groups. The increases in the LVEF and the RWMI were significantly correlated with the time interval from the first preinfarction angina attack to the onset of AMI (r = 0.622, p < 0.05 and r = 0.646, p < 0.05, respectively), but the enzymatic infarct size was not.

CONCLUSIONS

The beneficial effect of preinfarction angina on left ventricular wall motion, independently of collateral flows, indicates the existence of the PC effect in humans. The greater protective effect of a longer time interval between angina pectoris and AMI suggests that the protection is due to a delayed PC effect.

Clinical effects of ischemic preconditioning

A variety of experimental studies have confirmed that preconditioning the myocardium by brief periods of ischemia represents a powerful cardioprotective effect resulting in a reduction of infarct size. After 15 years of research in the experimental laboratory, some evidence shows the existence of preconditioning in human patients with coronary artery disease: repeated balloon inflations before coronary angioplasty induce preconditioning-like effects; moreover, some studies demonstrate better clinical outcome in patients with angina before acute myocardial infarction, resembling a preconditioning effect. So far, a few drugs have been identified as potential mediators of preconditioning, e.g., adenosine, adenosine receptor agonists, and adenosine triphosphate-sensitive potassium channel openers. Before coronary angioplasty and heart surgery, these preconditioning mimetics might be used to protect myocardial tissue by means of preconditioning. Further research is required before preconditioning mimetics could be used for therapy in patients with chronic myocardial ischemia. Possible antipreconditioning effects of several drugs, e.g., sulfonylurea drugs have to be considered in the treatment of patients with coronary artery disease.