The effect of preinfarction angina on clinical reperfusion time in patients with acute myocardial infarction receiving successful thrombolytic therapy

BACKGROUND: Preinfarction angina (PA) and early reperfusion of infarct-related arteries have been shown to reduce infarct size in patients with acute myocardial infarction (AMI). The beneficial effects of PA on infarct size have been attributed to the development of ischemic preconditioning and faster coronary recanalization in patients treated with thrombolytic therapy (TT). OBJECTIVE: To evaluate the effect of PA on clinical coronary reperfusion time in patients with AMI receiving successful TT. METHODS: Seventy-five patients presenting with AMI (within 6 h after the initial onset of symptoms) were studied. All patients received TT and were evaluated with coronary angiography (CA) at predischarge. The patients were divided into two groups: group 1 (PA-positive) comprised those who experienced a new onset of prodromal angina within 72 h before the onset of AMI. Group 2 (PA-negative) comprised those who had a sudden onset of AMI without the preceding angina. The successful myocardial reperfusion criteria after TT were ST segment resolution of 50% or greater, the appearance of reperfusion arrhythmias and the resolution of chest pain. The time of reperfusion criteria was recorded after TT. CA was performed in all patients at predischarge. Patients with no patent infarct-related arteries on CA and clinical failure of reperfusion were excluded from the study. RESULTS: Clinical characteristics, risk factors and angiographic findings did not differ significantly between the groups. The time interval from the start of continuous chest pain to TT was also similar between the groups. The left ventricular ejection fraction was higher and there were less frequent ventricular arrhythmias in patients with PA than in those without PA (47.9+/-7.4 versus 44.4+/-8.1, P=0.041, and 17.1% versus 37.5%, P=0.043, respectively). The clinical reperfusion time was significantly shorter in the patients with PA than in those without PA (68.2+/-24.5 min versus 81.4+/-19.3, P=0.012). The clinical reperfusion time was positively correlated with age and the time interval from the start of continuous chest pain to TT but inversely related to the presence of PA. CONCLUSIONS: In patients with AMI preceded by PA, TT resulted in more rapid clinical reperfusion than in patients without PA. Thus, earlier myocardial reperfusion may account for smaller infarct size and better prognosis in patients with PA.     

Effect of preinfarction angina pectoris on ST-segment resolution after primary coronary angioplasty for acute myocardial infarction

The presence of preinfarction angina has been shown to exert a favorable effect on left ventricular function after acute myocardial infarction (AMI). Whether or not preinfarction angina is beneficial for myocardial tissue reperfusion, however, remains to be determined. We sought to evaluate the influence of preinfarction angina on resolution of ST-segment elevation, which could be affected by microcirculatory damage after recanalization therapy. We studied 96 patients with a first AMI in whom Thrombolysis In Myocardial Infarction (TIMI)-3 flow in the infarct-related artery was established by primary angioplasty. Percent reduction in the sum of ST elevation from baseline to 1 hour after angioplasty (percent delta summation operator ST) was examined. Poor ST resolution, defined as percent delta summation operator ST <50%, was observed in 25 patients, who had a worse clinical outcome, larger infarct size, and poorer left ventricular function. On multivariate analysis, the absence of preinfarction angina, as well as anterior wall infarction, were major independent predictors of poor ST resolution, whereas age, sex, coronary risk factors, ischemic time, Killip class on admission, multivessel disease, initial TIMI flow grade, and extent of collaterals were not significant. Patients with preinfarction angina had a greater degree of ST-segment resolution than those without angina (71 +/- 21% vs 49 +/- 43%, p = 0.02). Additional ST elevation after reperfusion was noted exclusively in patients without preinfarction angina (p = 0.02). Preinfarction angina is associated with a greater degree of ST-segment resolution in patients with TIMI-3 flow after primary angioplasty, suggesting a protective effect of preinfarction angina against microcirculatory damage after reperfusion.     

Preinfarction angina protects against out-of-hospital ventricular fibrillation in patients with acute occlusion of the left coronary artery.

OBJECTIVES: The goal of this study was to evaluate the effect of preconditioning on out-of-hospital ventricular fibrillation (VF) in patients with acute myocardial infarction (AMI). BACKGROUND: More than half of the deaths associated with AMI occur out of the hospital and within 1 h of symptom onset. In humans, preinfarction angina (PA), which can serve as a surrogate marker for preconditioning, reduces infarct size, but the protective effect against out-of-hospital VF has not been investigated. METHODS: Preinfarction angina status and acute coronary angiographic findings of 72 consecutive patients with AMI complicated by out-of-hospital VF were compared with 144 matched controls without this complication. RESULTS: Preinfarction angina is associated with a lower risk for VF (odds ratio [OR]: 0.40, 95% confidence interval [CI]: 0.18 to 0.88). In patients with acute occlusion of the left coronary artery (LCA) (n = 136), the risk reduction is pronounced (OR: 0.25, 95% CI: 0.10 to 0.66), whereas, in patients with acute occlusion of the right coronary artery (RCA) (n = 67), the protective effect of PA on VF was not observed (OR: 2.25, 95% CI: 0.45 to 11.22). Subgroup and multivariate analyses show that the protective effect is independent of cardiovascular risk factors, preinfarction treatment with beta-adrenergic blocking agents or aspirin, the presence of collaterals or residual antegrade flow or the extent of coronary artery disease. CONCLUSIONS: Preinfarction angina protects against out-of-hospital VF in patients with acute occlusion of the LCA. This protection is independent of risk factors or coronary anatomy. A larger study is needed to examine the apparently different effect in patients with acute occlusion of the RCA.     

Multiple episodes of ischemic preconditioning are not associated with loss of benefit: preliminary clinical experience

BACKGROUND: As a clinical analogue of ischemic preconditioning (IP), preinfarction angina (PA) shares a well-documented protective effect in the setting of acute myocardial infarction (AMI) by reducing infarct size, preserving left ventricular function and improving prognosis. In the experimental setting, multiple cycles of IP may induce the loss of this protection. OBJECTIVE: To evaluate the effect of repeated cycles of PA on clinical outcomes in patients exhibiting a first AMI. METHODS: Seventy-four consecutive patients with AMI, in whom PA was the surrogate of experimental IP, were studied prospectively. All patients had poor or no collaterals. The patients were divided into three groups: group 1 (n=32) comprised patients without PA (control subjects); groups 2 (n=24) and 3 (n=18) comprised patients reporting one to four and more than four episodes of new-onset PA, respectively (preconditioned groups). Both of the preconditioned groups were compared with the control subjects with regard to creatine kinase-MB release, corrected Q-T interval (QTc) at discharge and major in-hospital complications. RESULTS: Compared with the control subjects, groups 2 and 3 exhibited reduced creatine kinase-MB release (75+/-26 IU/L and 85+/-22 IU/L versus 172+/-13 IU/L, P=0.004 and P=0.024, respectively), lower discharge QTc values (418+/-15 ms and 422+/-19 ms versus 443+/-38 ms, P=0.004 and P=0.031, respectively), and a reduced incidence of postinfarction angina (25% and 11% versus 44%, P<0.05), arrhythmias (0% and 0% versus 22%, P<0.05) and pulmonary edema (4% and 0% versus 28%, P<0.05). CONCLUSIONS: Regardless of the number of recurrences, IP seems to be a powerful intervention to reduce infarct size, limit QTc at discharge and improve the outcome in patients with AMI.     

Absence of preinfarction angina is associated with a risk of no-reflow phenomenon after primary coronary angioplasty for a first anterior wall acute myocardial infarction

BACKGROUND: No-reflow phenomenon after primary coronary angioplasty is associated with poorer left ventricular (LV) function and prognosis after acute myocardial infarction (AMI). The purpose of this study was to determine the clinical significance of preinfarction angina in the no-reflow phenomenon. METHODS AND RESULTS: A total of 40 patients with first anterior AMI were examined. All patients underwent primary balloon angioplasty or stenting within 12 h of the onset of AMI. No-reflow, defined as TIMI grade 2 flow or less without residual stenosis after angioplasty, was observed in 15 patients. Patients with no-reflow were older (67+/-9 vs. 58+/-10 years, P=0.006) and had a lower incidence of preinfarction angina (7% vs. 48%, P=0.01) than those without no-reflow. Patients with no-reflow had poorer LV function at predischarge and a higher incidence of pump failure, LV aneurysm, malignant ventricular arrhythmias or cardiac death during the hospital course in association with higher peak serum C-reactive protein levels (12.7+/-8.0 vs. 7.1+/-5.5 mg/dl, P=0.02). Multivariate analysis showed that the absence of preinfarction angina was a major independent determinant of no-reflow (RR=17.1, P=0.02). CONCLUSIONS: The absence of preinfarction angina is more frequently observed in patients with no-reflow. The beneficial effect of preinfarction angina on LV function may be explained, at least in part, by prevention of no-reflow after reperfusion.     

Coronary flow velocity immediately after primary coronary stenting as a predictor of ventricular wall motion recovery in acute myocardial infarction

OBJECTIVES

The purpose of this study was to examine the relationship between the pattern of coronary blood flow velocity immediately after successful primary stenting and the recovery of left ventricular (LV) wall motion in patients with acute myocardial infarction (AMI).

BACKGROUND

It is difficult to predict the recovery of LV wall motion immediately after direct angioplasty in AMI. Recent reports indicate that dysfunctional coronary microcirculation is an important determinant of prognosis for AMI patients after successful reperfusion.

METHODS

We measured left anterior descending coronary flow velocity variables using a Doppler guide wire immediately after successful primary stenting in 31 patients with their first anterior AMI. The patients were divided into two groups: those with and those without early systolic reverse flow (ESRF). Changes in LV regional wall motion (RWM) and ejection fraction (EF) at admission and at discharge were compared between the two groups. Coronary flow velocity variables immediately after primary stenting were compared with changes in left ventriculographic indexes.

RESULTS

The change in RWM was significantly greater in the non-ESRF group than it was in the ESRF group (0.9 ± 0.7 vs. −0.1 ± 0.3 standard deviation/chord, respectively, p < 0.001). The change in EF was also significantly greater in the non-ESRF group than it was in the ESRF group (10 ± 10 vs. 1 ± 6%, respectively, p < 0.05). In the non-ESRF group (diastolic to systolic velocity ratio [DSVR] <3.0), the DSVR correlated positively with the change in RWM (r = 0.60, p < 0.005, n = 24) and the change in EF (r = 0.52, p < 0.01).

CONCLUSIONS

The coronary flow velocity pattern measured immediately after successful primary stenting is predictive of the recovery of regional and global LV function in patients with AMI.     

Relation between the timing of the last preinfarction angina and microvascular reperfusion in patients with recanalized acute myocardial infarction

In patients with recanalized acute myocardial infarction (AMI), the relation between the timing of preinfarction angina (PA) and microvascular reperfusion remains unclear. A total of 186 patients (114 with anterior and 72 with inferior AMI) who had total occlusion and TIMI 3 recanalization < or = 6 hours from the onset of AMI were divided into 4 groups according to the time interval between the last episode of PA and the onset of AMI: < or = 2 hours (group A, n = 52); 2 to 48 hours (group B, n = 43), > or = 48 hours (group C, n = 33), and no PA (group D, n = 58). The angiographic myocardial blush grade, a marker of microvascular reperfusion, was retrospectively assessed immediately after recanalization. There were no differences in baseline characteristics, except for sex among the 4 groups. Myocardial blush grade 3 was more frequent (42% vs 21%, 9%, and 14%) and peak creatine kinase was lower (2659 vs 3455, 4422, and 4622 mU/mL) in group A than in groups B, C, and D (all P < 0.05). Multivariate analysis showed that PA occurring < or = 2 hours before AMI (OR 3.88, P < 0.05), a smaller summed ST-segment elevation before recanalization (OR 0.84, P < 0.01), earlier time to recanalization (OR 0.52, P < 0.05), and interior AMI (OR 4.87, P < 0.05) were independently associated with adequate microvascular reperfusion. We conclude that PA < or = 2 hours before the onset of AMI is independently associated with adequate microvascular reperfusion after recanalization in patients with AMI.     

Preinfarction angina limits myocardial infarction size in nondiabetic patients treated with primary coronary angioplasty

OBJECTIVE: To evaluate myocardial necrosis extent after myocardial infarction (MI) and reperfusion with primary coronary angioplasty in nondiabetic patients and the relationship with unstable preinfarction angina (PA). DESIGN: Prospective cohort study. SETTING: Studies suggest PA limits infarct size. This effect is questioned in patients treated with primary coronary angioplasty. PATIENTS: Seventy-eight, nondiabetic, consecutive MI patients. INTERVENTIONS: Primary coronary angioplasty and scintigraphic study to assess the myocardial infarct size. MAIN OUTCOME MEASURES: Scintigraphic myocardial infarct size. RESULTS: There were 32 patients with PA (PA +) and 46 without PA (PA -) in the 24-h period prior to MI onset. There were no significant differences in the baseline characteristics between the two groups. The scintigraphy indicated myocardial infarct size significantly smaller in PA + patients: mean, 18.0% (SD, 14.7) vs 27.0% (SD, 20.1) [p = 0.033]. This occurs even though Thrombolysis in Myocardial Infarction grade 3 flow achieved in both groups was similar (84.8% vs 84.4%, p = 1.000). We found a higher percentage of ST-segment resolution (>/= 70%) in PA + patients (65.6% vs 45.7%, p = 0.082) together with a lower incidence of left ventricular systolic dysfunction (3.2% vs 18.6%, p = 0.071). CONCLUSIONS: PA exerts a beneficial effect in nondiabetic patients with ST-segment elevation acute MI even when treated with primary PCI. The infarct size is limited, and left ventricular systolic function is preserved. The effects may be related to a better preservation of tissue reperfusion in patients with PA.     

Effect of preinfarction angina pectoris on microcirculation in patients with reperfused acute myocardial infarction

Preinfarction angina pectoris has been suggested in some studies to have a beneficial effect on left ventricular function after acute myocardial infarction (AMI). The precise mechanisms of this protection have not been fully elucidated. The effect of preinfarction angina on myocardial tissue perfusion also needs to be clarified. In this study, we investigated the influence of preinfarction angina on microvasculatory damage by using ST-segment resolution and pressure-derived collateral flow index (CFIp) as a marker of microcirculatory perfusion. METHODS: We studied 41 patients with a first AMI in whom thrombolysis in myocardial infarction (TIMI) grade 3 flow in the infarct-related artery was established by thrombolytic therapy. The percent resolution of ST-segment deviation (deltasigma ST) after thrombolysis was determined. All of the patients had TIMI grade 3 flow in IRA at the coronary angiography, which was done a mean of 4 days after AMI. Intracoronary pressure measurements and stent implantation to the IRA were performed. After angiography, CFIp was calculated as the ratio of simultaneously measured coronary wedge pressure-central venous pressure (Pv) to mean aortic pressure-Pv. RESULTS: Patients with preinfarction angina pectoris had greater percent deltasigma ST than those without PA (67 +/- 18% vs. 44 +/- 24%, p = 0.03).The mean of the coronary wedge pressure (16.4 +/- 7.4 compared with 23.2 +/- 9.4, P < 0.03) and the pressure-derived collateral flow index (0.15 +/- 0.10 compared with 0.22 +/- 0.08, P < 0.03) were significantly lower in patients with preinfarction angina compared to those without. CONCLUSION: Preinfarction angina is associated with a greater degree of ST-segment resolution and lower CFI-p in patients with TIMI-3 reflow after thrombolysis. These findings suggest that a protective effect of preinfarction angina against reperfusion injury may result in greater ST resolution and lower CFIp after AMI.     

梗死前心绞痛对急性心肌梗死患者直接经皮冠状动脉介入治疗术后的影响

目的　探讨梗死前心绞痛对首次急性心肌梗死(AMI)患者直接经皮冠状动脉介入治疗(PCI)术后的近期影响。方法　将120例首次AMI患者分成有梗死前心绞痛史组(A组, 68例)和无梗死前心绞痛史组(B组, 52例),在发病12小时内行直接PCI术,分析梗死前心绞痛对肌酸肌酶(CK)峰值浓度、左心室功能和临床转归的影响。结果　(1)A组CK及CK MB峰值浓度均显著低于B组(P<0. 05); (2)A组冠状动脉自发再通率高于B组(P<0. 05),A组无再流现象发生率低于B组(P<0. 05); (3)A组左室射血分数高于B组(P<0. 05); (4)A组心力衰竭发生率及再梗死率低于B组(P<0. 05)。结论　梗死前心绞痛可能促进AMI患者梗死相关动脉自发再通的发生,减少直接PCI术后无再流现象发生,改善患者左心室功能和临床预后。     

Significance of preinfarction angina for preservation of left ventricular function in acute myocardial infarction.

The effect of preinfarction angina on the preservation of left ventricular function was evaluated with the use of cineventriculography in 37 patients who had either total or subtotal occlusion of the proximal left anterior descending coronary artery during the convalescent period of myocardial infarction. In 15 patients who had preinfarction angina more than 1 week before the onset of acute myocardial infarction (group A), the global left ventricular ejection fraction was 54 +/- 3% (SEM) and regional wall motion in the infarct area was 10 +/- 3%. In 10 patients who had preinfarction angina occurred within 1 week before the onset of acute myocardial infarction (group B), the left ventricular ejection fraction and regional wall motion in the infarct area were 42 +/- 3% and 1 +/- 2%, respectively. In 12 patients without preinfarction angina (group C), the left ventricular ejection fraction and regional wall motion in the infarct area were 38 +/- 3% and -1 +/- 2%, respectively. In groups B and C, both the left ventricular ejection fraction and regional wall motion in the infarct area were lower than those in group A (p less than 0.05). The collateral circulation at the onset of acute myocardial infarction was better in group A compared with groups B and C (p less than 0.05). Thus the collateral circulation, promoted by repetitive anginal episodes indicative of myocardial ischemia, causes the preservation of myocardial function.     

Beneficial effect of preinfarction angina on in-hospital outcome is preserved in elderly patients undergoing coronary intervention for anterior acute myocardial infarction.

BACKGROUND: Preinfarction angina improves survival after acute myocardial infarction (AMI) in nonelderly but not elderly patients in the thrombolytic era. However, it remains unclear whether preinfarction angina has a beneficial effect on clinical outcome in elderly patients undergoing percutaneous coronary intervention (PCI). METHODS AND RESULTS: The study group comprised 484 anterior AMI patients who were admitted within 24 h of onset and underwent emergency PCI. Patients were divided into 2 groups: those aged < 70 years (nonelderly patients, n = 290) and those aged > or = 70 years (elderly patients, n = 194). Angina within 24 h before AMI was present in 42% of nonelderly patients and in 37% of elderly patients. In nonelderly patients, preinfarction angina was associated with a lower in-hospital mortality rate (1% vs 7%, p = 0.02). Similarly, in elderly patients, preinfarction angina was associated with a lower in-hospital mortality rate (6% vs 16%, p = 0.03). Multivariate analysis showed that the absence of preinfarction angina was an independent predictor of in-hospital mortality in both nonelderly (odds ratio 4.20; 95% confidence interval (CI) 1.20-10.6; p = 0.04) and elderly patients (odds ratio 3.04; 95%CI 1.06-18.1; p = 0.04). CONCLUSIONS: Angina within the 24 h before AMI is associated with better in-hospital outcomes in elderly and nonelderly patients.     

梗死前心绞痛对急性心肌梗死患者直接PCI术后的影响

目的　探讨梗死前心绞痛对首次急性心肌梗死 (AMI)患者直接经皮冠状动脉介入治疗 (PCI)术后的近期影响。方法　 10 0例首次 AMI患者 ,按梗死前有无心绞痛史分为 A(有心绞痛史 ,5 5例 )、B(无心绞痛史 ,4 5例 ) 2组 ,所有患者均在发病 12 h内行直接 PCI术。术前术后监测心肌酶变化 ;术后 2周行心血池显像测定左心室射血分数。并观察住院期间心律失常、心力衰竭或心源性休克的发生率及再梗死率、病死率。结果　 (1) A组肌酸激酶同工酶峰值低于 B组 (P<0 .0 5 )。 (2 ) A组自溶现象发生率高于 B组 (P<0 .0 5 ) ;A组无再流现象发生率低于 B组 (P<0 .0 5 )。 (3) A组左心室射血分数高于 B组 (P<0 .0 5 )。 (4 ) A组心力衰竭或心源性休克的发生率和再梗死率均低于B组 (P<0 .0 5 )。结论　梗死前心绞痛可促进 AMI患者梗死相关动脉自溶现象的产生 ,并可减少直接 PCI术后无再流现象的发生 ,从而改善心室功能和近期预后     

直接经皮冠状动脉介入治疗对有无梗死前心绞痛患者心肌存活性和心室收缩同步性的影响

目的　探讨直接经皮冠状动脉介入治疗 (PCI)对有无梗死前心绞痛的急性心肌梗死 (AMI)患者心肌存活性和心室收缩同步性的近期影响。方法　 87例首次 AMI患者 ,按梗死前有无心绞痛分为 3组 :A组 :无心绞痛史 30例。 B组 :梗死前 4 8h内有心绞痛史 39例。 C组 :仅在梗死前 >4 8h有心绞痛史 18例。所有患者均在发病 6 h内行直接 PCI术。术后 1周、4周行 99m　 Tc- MIBI心肌灌注断层显像 (SPECT)测定心肌存活性 ;术后 2周行 99m　 Tc心血池显像测定心室收缩同步性参数。结果　 (1) B组肌酸激酶同工酶 (CK- MB)峰值显著低于 A组 (P<0 .0 1)。 (2 ) B组放射性缺损面积 (MIA)小于 A组 (P<0 .0 5 ) ;AMI后 4周与 1周比较 ,B组 MIA显著缩小 (P<0 .0 1) ,病变区放射性计数显著增加 (P<0 .0 1) ;C组和 A组前后比较均无显著差异。 (3)心功能 :B组左心室射血分数 (L VEF)高于 A组 (P<0 .0 1) ;左心室收缩同步性 :B组左心室相角程 (L PS)低于 A组 (P<0 .0 5 ) ;以上各参数 ,C组和 A组比较均无显著差异。结论　 (1)首次急性心肌梗死前 4 8h内心绞痛发作可导致心肌缺血预适应 (ischemic preconditioning,IP)的产生 ,并可缩小心肌梗死面积 ,保护心功能。 (2 )直接 PCI可显著提高有 IP的急性心肌梗死患者的近期心肌存活性和     

急性心肌梗塞前心绞痛对其急诊冠脉介入术后再流现象的影响

目的:探讨梗塞前心绞痛(PIA)对急性心肌梗塞(AMI)患者经皮冠状动脉介入治疗(PCI)后无再流现象的影响。方法:230例行急诊PCI的AMI患者依其是否发生再流现象分为两组:无再流组(25例)和再流组(205例)。监测再灌注心律失常、心肌酶谱和C反应蛋白(CRP)变化;超声心动图测定心功能,观察室壁瘤、心力衰竭发生率和住院病死率。结果:无再流组PIA发生率显著低于再流组(P<0.01);而前壁梗塞的发生率高于再流组(P<0.01),CRP值明显高于再流组(P<0.05);再灌注心律失常发生率、肌酸激酶同工酶峰值和水平均显著高于再流组(P<0.01)。左室射血分数显著低于再流组(P<0.05);心力衰竭、室壁瘤发生率和死亡率均高于再流组(P<0.01)。而多元回归分析结果显示,缺乏PIA是发生无再流现象的独立预测因素(OR=3.71,P=0.01)。结论:缺乏PIA是发生无再流现象的独立预测因素。     

Diabetes mellitus prevents ischemic preconditioning in patients with a first acute anterior wall myocardial infarction

OBJECTIVES: This study was undertaken to assess whether prodromal angina could have beneficial effects in diabetic patients with acute myocardial infarction (AMI). BACKGROUND: Prodromal angina occurring shortly before the onset of AMI is associated with favorable outcomes by the mechanism of ischemic preconditioning. However, little is known about the impact of diabetes on ischemic preconditioning. METHODS: We studied 611 patients with a first anterior wall AMI who underwent emergency catheterization within 12 h after the onset of chest pain: 490 patients without diabetes and 121 patients with non-insulin treated diabetes. Prodromal angina was defined as angina episode(s) occurring within 24 h before the onset of AMI. Serial contrast left ventriculograms were obtained in 424 patients at the time of acute and predischarge catheterization. RESULTS: In non-diabetic patients, prodromal angina was associated with lower peak creatine kinase (CK) value (3,068 +/- 2,647 IU/l vs. 3,601 +/- 2,462 IU/l, p = 0.037), larger increase in left ventricular ejection fraction (LVEF) (10.1 +/- 13.0% vs. 5.8 +/- 13.4%, p = 0.004) and lower in-hospital mortality (3.4% vs. 9.3%, p = 0.015). On the contrary, in diabetic patients, there was no significant difference in peak CK value (3,382 +/- 2,520 IU/l vs. 3,233 +/- 2,412 IU/l, p = NS), the change in LVEF (6.7 +/- 13.8% vs. 7.1 +/- 12.4%, p = NS) and in-hospital mortality (8.8% vs. 11.0%, p = NS) between patients with and patients without prodromal angina. CONCLUSIONS: Prodromal angina limited infarct size, enhanced recovery of LV function and improved survival in non-diabetic patients with AMI. However, such beneficial effects of prodromal angina were not observed in diabetic patients, suggesting that diabetes might prevent ischemic preconditioning.     

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.     

High level of physical activity preserves the cardioprotective effect of preinfarction angina in elderly patients.

OBJECTIVES: The study investigated the effects of physical activity on preinfarction angina, a clinical equivalent of ischemic preconditioning (PC), in adult and elderly patients with acute myocardial infarction (AMI). BACKGROUND: Preinfarction angina seems to confer protection against in-hospital mortality in adult but not in elderly patients. However, it has been experimentally demonstrated that exercise training restores the protective effect of PC in the aging heart. METHODS: We retrospectively verified whether physical activity preserved the protective effect of preinfarction angina against in-hospital mortality in 557 elderly patients with AMI. Physical activity was quantified according to the Physical Activity Scale for the Elderly (PASE). RESULTS: In-hospital mortality was 22.2% in elderly patients with preinfarction angina and 27.2% in those without (p = 0.20). When the PASE score was stratified in quartiles (0 to 40, 41 to 56, 57 to 90, >90), a high score was strongly associated with reduced in-hospital mortality (30.8%, 32.2%, 17.2% and 15.3%, respectively, p < 0.001 for trend). Interestingly, a high level of physical activity reduced in-hospital mortality in elderly patients with preinfarction angina (35.7%, 35.4%, 12.3% and 4.23%, respectively, p < 0.001 for trend) but not in those without (23.0%, 27.2%, 26.0% and 35.0%, respectively, p = 0.35 for trend). Accordingly, the protective role of preinfarction angina on in-hospital mortality was present only in elderly patients showing a high level of physical activity (adjusted odds ratio, 0.09; 95% confidence interval, 0.01 to 0.57; p < 0.05). CONCLUSIONS: Physical activity and not preinfarction angina protects against in-hospital mortality in elderly patients with myocardial infarction. Nevertheless, the protective effect of preinfarction angina is preserved in elderly patients with a high level of physical activity.     

Is the beneficial effect of preinfarction angina related to an immune response?

Immune-mediated mechanisms are thought to play a key role in the development of coronary artery disease and its thrombotic complications. Preinfarction angina has been suggested to improve left ventricular function and short-term outcomes. The purpose of the present study was to investigate the relation between the immune response and in-hospital clinical course in preinfarction angina. We prospectively evaluated 93 patients. Forty-three patients exhibited preinfarction angina within 24 hours before the onset of acute myocardial infarction (AMI) (preinfarction angina group) and 50 patients were free from preinfarction angina (sudden onset group). The incidence of complications (heart failure, recurrent angina, arrhythmia and coronary interventions) and in-hospital mortality were assessed in the two study groups. We detected some immune markers, including white blood cells, C-reactive protein, immunoglobulins, and complement. White blood cells and CRP were significantly lower in the preinfarction angina group than in the sudden onset group (P < 0.001, P < 0.005, respectively). Conversely, IgE and C(4) were significantly higher in the preinfarction angina group than in the sudden onset group (P < 0.001, P < 0.001, respectively). The incidences of heart failure and severe arrhythmias were lower in the preinfarction group than in the sudden onset group (P < 0.005, P < 0.05 respectively). The beneficial effect of preinfarction angina may be associated with an immune-inflammatory response modified by a brief ischemic episode.     

Comparison of protective effects of preinfarction angina pectoris in acute myocardial infarction treated by thrombolysis versus by primary coronary angioplasty with stenting.

The protective effects of preinfarction angina were evaluated in acute myocardial infarction (AMI) treated by primary percutaneous transluminal coronary angioplasty (PTCA) and stenting. We studied 613 patients with AMI. Group 1 (n = 306) was treated by conventional medical therapies and coronary thrombolysis and group 2 (n = 307) was treated by primary PTCA supported by stenting. Each group was subdivided into those with and without preinfarction angina within 24 hours before the onset of AMI. There was no significant difference in clinical characteristics between the subgroups of groups 1 and 2. In group 1, there were differences between patients with preinfarction angina (n = 84) and those without (n = 222) in in-hospital mortality (11% vs 18%), pump failure (Killip classes 3 and 4) (11% vs 21%, p <0.05), left ventricular ejection fraction at discharge (52 +/- 13% vs 48 +/- 14%, p <0.05), and peak creatine kinase (2,106 +/- 1,637 vs 2,764 +/- 2,154 U/L, p <0.02). In group 2, however, there was no significant difference between those with preinfarction angina (n = 82) and those without (n = 225) in mortality (6% vs 6%), pump failure (12% vs 12%), left ventricular ejection fraction (50 +/- 13% vs 50 +/- 13%) and peak creatine kinase (3,285 +/- 2,306 vs 3,291 +/- 2,262 U/L). Multivariate analysis indicated that preinfarction angina was an independent determinant of in-hospital death and pump failure in group 1, but not in group 2. We conclude that the protective effects of preinfarction angina in AMI are not evident in those treated by primary PTCA and stenting, possibly because of the overwhelming protective effects of complete coronary revascularization provided by primary PTCA and stenting.