In vivo optical coherence tomography of very late drug-eluting stent thrombosis compared with late in-stent restenosis.

BACKGROUND: Autopsy findings have suggested delayed arterial healing as a primary cause of very late stent thrombosis (VLST) after drug-eluting stent (DES) implantation. METHODS AND RESULTS: Optical coherence tomography of DES-treated lesions that developed VLST (n = 6) was compared with that of DES-treated lesions that developed late in-stent restenosis (L-ISR: n = 32) among patients with recurrent ischemia >1 year after DES implantation (mean, 37 ± 17 months), and with the stented segment without any evidence of VLST or L-ISR (no-event: n = 20; mean, 38 ± 19 months). The proportion of uncovered and malapposed struts in each stented segment was evaluated. A total of 961 frames, 9,763 struts were analyzed. The proportion of uncovered struts was higher in the VLST group than in the L-ISR group and the no-event group (29.2 ± 22.8%, 7.9 ± 9.7%, and 7.6 ± 8.0%, respectively; P = 0.0002). The proportion of malapposed struts was higher in the VLST group than in the no-event group (7.3 ± 8.7% vs 1.1 ± 2.4%, P = 0.01). Two patients in the VLST group had lower rates of uncovered and malapposed struts, but this involved lipid-laden-like neointima with disruptions. CONCLUSIONS: Delayed neointimal coverage and incomplete stent apposition were frequently observed in the DES-treated lesions that developed very late thrombosis. Lipid-laden-like neointima with disruption within the DES may be another possible mechanism for very late thrombosis.

The potential benefits and risks of the use of dual antiplatelet therapy beyond 6 months following sirolimus-eluting stent implantation for low-risk patients.

BACKGROUND: The optimal duration of dual antiplatelet therapy (DAT) in patients undergoing intracoronary sirolimus-eluting stent implantation remains controversial. OBJECTIVE: To evaluate the clinical effects of long duration DAT in patients undergoing intracoronary sirolimus-eluting stent implantation in daily practice. In addition, to attempt to identify the optimal duration of DAT after implantation of a sirolimus-eluting stent. METHODS: We retrospectively report on 1293 consecutive patients who underwent successful intracoronary sirolimus-eluting stent implantation. We analyzed the cumulative incidence of stent thrombosis, non-fatal myocardial infarction (MI), death from cardiac causes, and the cumulative incidence of bleeding complications. RESULTS: We compared the study end point in patients who received DAT for <6 months (n=1136) with that for patients who received DAT for >6 months (n=157). The median follow-up period was 1260 ± 462 days. Major bleeding occurred in 35 patients and intracranial hemorrhage in 8. In patients on DAT for >6 months, the incidence of any bleedings, major bleedings, and intracranial hemorrhage was significantly increased. On the other hand, there was no significant difference between the two groups in the risk of the primary end points (stent thrombosis, non-fatal MI, death from cardiac causes, death or MI). CONCLUSIONS: Prolonged DAT for more than 6 months was not significantly more beneficial than aspirin monotherapy in reducing the risk of the occurrence of acute MI, stent thrombosis, and death, although it was associated with an increase in bleeding complications for low-risk patients.

The impact of gender difference on the effects of preinfarction angina on microvascular damage with reperfused myocardial infarction.

BACKGROUND: Few studies have addressed gender differences in evoking preconditioning. In an experimental study, it was reported that the preconditioning effect disappeared after gonadectomy. OBJECTIVES: We sought to determine the effects of preinfarction angina (PA) on myocardial damage using intravenous contrast echocardiography. METHODS: We studied 334 consecutive patients with anterior myocardial infarction (AMI) who underwent successful angioplasty. All patients underwent myocardial contrast echocardiography (MCE) 14 days after percutaneous coronary intervention (PCI). Contrast defect was calculated as contrast defect area/myocardial area. Typical angina occurring in the 24-hour period preceding myocardial infarction was present in 133 patients (29 women) (group PA) and absent in 201 patients (43 women) (group non-PA). All women were postmenopausal. RESULTS: The contrast defect size and peak creatinine phosphokinase (max CPK) level in women were both significantly higher than that of men in group PA (18.3% +/- 6.3% vs 11.9% +/- 9.0%; P < 0.01 and 5000 +/- 599 IU/L vs 2672 +/- 221 IU/L; P < 0.005). The functional status of the myocardium among group PA, as expressed by risk area wall motion score index, was better in men than in women at 14 days (1.1 +/- 0.8 vs 1.7 +/- 0.8; P < 0.01) and at 6 months (0.7 +/- 0.4 vs 1.6 +/- 0.6; P < 0.01). However there were no significant gender differences in group non-PA. Multivariate regression analysis showed that the female gender (P < 0.05) was a significant independent predictor for microvascular damage. CONCLUSIONS: These findings suggest that preconditioning effects were attenuated in women with reperfused AMI.

Waist circumference reduction is more strongly correlated with the improvement in endothelial function after acute coronary syndrome than body mass index reduction.

BACKGROUND: Endothelial function predicts recurrence of adverse cardiac events in patients with acute coronary syndromes (ACS). Moreover, the recovery of endothelial function correlates with cardiac event-free survival. OBJECTIVES: The aim of this study was to determine which clinical factors correlate with the improvement in endothelial function after ACS. METHODS: Vascular endothelial function was assessed in 98 patients with ACS by flow-mediated dilation (FMD) of the brachial artery using high-resolution ultrasound at 2 weeks and 6 months after ACS. We measured several risk parameters including plasma markers of glucose homeostasis, lipids, and blood pressure at baseline and at 6 months after ACS. Body mass index (BMI) and waist circumference (WC) were also measured as anthropometric assessments. RESULTS: At baseline, FMD was significantly correlated with BMI, WC, high-density lipoprotein cholesterol, the homeostasis model assessment of insulin resistance, and brachial artery diameter (r=-0.32, p=0.001; r=-0.44, p<0.0001; r=0.34, p=0.0006; r=-0.21, p=0.04; r=-0.47, p<0.0001, respectively). In a stepwise multivariate regression analysis at baseline, larger WC and brachial artery diameter were independently correlated with lower brachial artery FMD (R(2)=0.319, p<0.0001). At 6 months, the change in FMD was significantly correlated with the change in WC and BMI (r=-0.59, p<0.0001; r=-0.33, p=0.001, respectively). In a stepwise multivariate regression analysis, WC reduction was independently correlated with improved FMD (R(2)=0.349, p<0.0001). CONCLUSIONS: WC reduction is more strongly correlated with the improvement of endothelial function after ACS than BMI reduction.

Relationship of admission neutrophil count to microvascular injury, left ventricular dilation, and long-term outcome in patients treated with primary angioplasty for acute myocardial infarction.

BACKGROUND: The relationship of admission neutrophil count to the degree of microvascular injury, left ventricular (LV) volume, and long-term outcome after acute myocardial infarction (AMI) was examined in the present study. METHODS AND RESULTS: The study group comprised 228 consecutive patients with a first anterior wall AMI who underwent primary angioplasty within 12 h of onset. The degree of microvascular injury was evaluated by Doppler guidewire. Adverse cardiac events were recorded during an average follow-up of 52+/-28 months. Using a receiver-operating characteristic analysis, a neutrophil count >or=7,260 cells/mm(3) was the best predictor of future cardiac events. By regression analysis, the neutrophil count significantly correlated with diastolic deceleration time (r=-0.40, p<0.0001), coronary flow reserve (r=-0.43, p<0.0001), and LV end-diastolic volume at 4 weeks (r=0.32, p<0.0001). Kaplan-Meier survival analysis showed a higher incidence of adverse cardiac events in patients with a high neutrophil count (p=0.002). By multivariate analysis, a neutrophil count >or=7,260 cells/mm(3) was an independent predictor of long-term adverse cardiac events (odds ratio 3.8, p=0.002). CONCLUSION: Neutrophilia on admission is associated with impaired microvascular perfusion, LV dilation, and long-term adverse cardiac events in patients treated with primary angioplasty for AMI.

Effects of smoking cessation on coronary endothelial function in patients with recent myocardial infarction.

BACKGROUND: Smoking is associated with an increased risk and extent of advanced atherosclerotic vascular disease, but few studies have examined the clinical effect of smoking cessation on human coronary endothelial function. OBJECTIVES: We sought to determine the effects of smoking cessation on endothelial function in patients with recent myocardial infarction. METHODS: Infarcted-not-related coronary arteries of 53 patients with acute myocardial infarction undergoing successful angioplasty were examined in two groups: smoking cessation group (n=35, 28 males, mean age 56 years) and non-smoking group (n=18, 10 males, mean age 65 years). We infused acetylcholine into the coronary artery and the diameter was assessed by quantitative angiography at baseline and 6 months after PTCA. RESULTS: The mean % diameter change from baseline was significantly more constricted in the smoking cessation group than in the non-smoking group (38%+/-5 vs. 19%+/-5, p<0.05). However, the response after six months was significantly decreased after smoking cessation (from 38%+/-5 to 28%+/-4, p<0.01). Multiple regression analysis showed smoking cessation (p=0.03) was a significant determinant factor for improvement of endothelial function. CONCLUSIONS: These findings suggest that just 6 months of smoking cessation improves coronary endothelial function in patients with recent myocardial infarction.

Usefulness of coronary flow reserve immediately after primary coronary angioplasty for acute myocardial infarction in predicting long-term adverse cardiac events.

Coronary flow reserve (CFR) evaluated immediately after reperfusion is thought to reflect the degree of microvascular injury and predict left ventricular (LV) functional recovery after acute myocardial infarction. It was hypothesized that CFR immediately after reperfusion would be predictive of the occurrence of long-term adverse cardiac events. Using a Doppler guidewire, CFR was evaluated immediately after primary coronary angioplasty in 118 consecutive patients with first anterior acute myocardial infarctions. Adverse cardiac events combining cardiac death, recurrent myocardial infarction, and congestive heart failure were recorded during an average follow-up period of 62 +/- 32 months. Using receiver-operating characteristic analysis, CFR 1.3 (n = 68). Patients with CFR 1.3. CFR was significantly correlated with the LV ejection fraction at 4 weeks (r = 0.50, p <0.0001) and LV end-diastolic volume at 4 weeks (r = -0.43, p <0.0001). Kaplan-Meier survival analysis showed a higher incidence of adverse cardiac events in patients with CFR

Relation between neutrophil counts on admission, microvascular injury, and left ventricular functional recovery in patients with an anterior wall first acute myocardial infarction treated with primary coronary angioplasty.

Increased neutrophil counts have been associated with an increased risk of adverse clinical events after acute myocardial infarction (AMI). We examined the association of neutrophil counts on admission with degree of microvascular injury and left ventricular functional recovery after primary coronary angioplasty in AMI. We studied 116 patients with a first anterior wall AMI who underwent primary coronary angioplasty within 12 hours of onset. Patients were categorized into 3 groups based on initial neutrophil count: low (<5,000/mm(3)), intermediate (5,000 to 10,000/mm(3)), and high (>10,000/mm(3)). Coronary flow velocity parameters were assessed immediately after reperfusion using a Doppler guidewire. We defined severe microvascular injury as the presence of systolic flow reversal and a diastolic deceleration time <600 ms. Echocardiographic wall motion was analyzed before revascularization and 4 weeks after revascularization. In patients with a high neutrophil count, systolic flow reversal was more frequently observed, diastolic deceleration time was shorter, and coronary flow reserve was lower. By regression analysis, neutrophil count significantly correlated with diastolic deceleration time (r = -0.38, p <0.0001), coronary flow reserve (r = -0.33, p = 0.0004), and score for change in wall motion (r = -0.36, p = 0.0004). Multivariate analysis showed that neutrophil count on admission was an independent predictor of severe microvascular injury (odds ratio 2.94, p = 0.02). In conclusion, neutrophilia on admission is associated with impaired microvascular reperfusion and poor functional recovery after primary coronary angioplasty.

Usefulness of ultrasonic strain measurements to predict regional wall motion recovery in patients with acute myocardial infarction after percutaneous coronary intervention.

Strain Doppler echocardiography can detect systolic regional myocardial dysfunction. This study assessed whether strain could predict recovery of regional left ventricular function in patients with acute myocardial infarction (AMI) after percutaneous coronary intervention. Forty-three patients with anterior AMI undergoing successful percutaneous coronary intervention of the left anterior descending coronary artery were studied. Longitudinal myocardial strain was measured at the left anterior descending coronary artery territory in the apical long-axis view within 24 hours after percutaneous coronary intervention. Regional wall motion was analyzed by the anterior wall motion score index (A-WMSI). Viable myocardium was defined as a decrease < or = 2.0 in A-WMSI. Patients were categorized as A-WMSI at 4 weeks into a viable group (n = 24) and a nonviable group (n = 19). End-systolic strain and peak strain were significantly lower in the nonviable group than in the viable group (-4.8 +/- 4.8% vs -9.9 +/- 4.7 %, p <0.005; -9.9 +/- 4.6 vs -13.5 +/- 4.1 %, p <0.05). Moreover, corrected time to peak strain (cTPS; time delay from end-systolic to peak strain/RR interval) was significantly longer in the nonviable group than in the viable group (0.19 +/- 0.04 vs 0.13 +/- 0.03, p <0.0001). For prediction of viable myocardium, cTPS <0.15 had a sensitivity of 95% and a specificity of 85%. In conclusion, strain, especially cTPS, is useful for predicting recovery of regional left ventricular function in patients with AMI after percutaneous coronary intervention.

The effects of atorvastatin on coronary endothelial function in patients with recent myocardial infarction.

BACKGROUND: Endothelial dysfunction is a key early event in atherosclerosis that occurs in acute coronary syndrome. It was reported that atorvastatin improves the endothelial function of skeletal muscle vessels, but the effect on the coronary artery is unknown. HYPOTHESIS: The purpose of this study is to determine the effects of atorvastatin on coronary endothelial function in humans. METHODS: Non-infarct-related coronary arteries of 48 patients with acute myocardial infarction who had undergone successful percutaneous transluminal coronary angioplasty were examined. Three groups were studied: hyperlipidemia with use of atorvastatin (Group 1, n=17), hyperlipidemia without statin use (Group 2, n=18), and normal cholesterol level controls (Group 3, n=13). Statin treatment was started at discharge. Acetylcholine (Ach) was infused into the coronary artery and the diameter was assessed by quantitative angiography at baseline and after 6 months. RESULTS: Acetylcholine given in doses of 1, 3, 10, and 30 mg/min increased the coronary artery diameter change in a dose-dependent manner. In the initial study, patients in the three groups had similar responses to Ach. The mean diameter change after 6 months was significantly improved in Group 1 compared with Groups 2 and 3 (-11 +/- 3% vs. -20 +/- 7% and -21 +/- 6%, respectively; p < 0.01 in each case). Multivariate regression analysis showed that atorvastatin (p < 0.01) was the significant determinant for improvement of endothelial function. CONCLUSIONS: These findings suggest that atorvastatin improves endothelial function of the coronary artery in patients with myocardial infarction.

Acute myocardial infarction caused by simultaneous occlusion of the right coronary artery and the left anterior descending coronary artery probably due to coronary spasm: a case report.

A 56-year-old man had an attack of chest pain associated with ST-segment elevation in both the inferolateral and anteroseptal leads on electrocardiography. Emergency coronary angiography showed thrombus in the mid right coronary artery and total occlusion in the distal left anterior descending coronary artery. Intravenous heparin infusion and antiplatelet therapy were given without other coronary intervention. After 1 week, repeat coronary angiography showed neither significant stenosis nor thrombus in the coronary arteries. Severe coronary artery spasm in the left coronary artery was induced by the provocation test with intracoronary injection of 50 microg acetylcholine. He had an uneventful hospital course. This unique case demonstrated intracoronary thrombus formation in the right coronary artery and left anterior descending coronary artery simultaneously due to suspected coronary spasm.

Ultrasonic tissue characterization predicts left ventricular remodeling in patients with acute anterior myocardial infarction after primary coronary angioplasty.

OBJECTIVES: The aim of this study was to assess the role of cyclic variation (CV) of myocardial integrated backscatter (IBS) in the prediction of left ventricular (LV) remodeling in patients with anterior acute myocardial infarction (AMI) after primary coronary angioplasty. BACKGROUND: Some studies have shown that the CV of myocardial IBS predicts myocardial viability for patients with AMI. METHODS: We recorded short-axis IBS images within 24 hours of angioplasty in 80 patients with anterior AMI. Two parameters were measured: the magnitude of CV and the normalized time delay (NTD). The increase in LV end-diastolic volume (LVEDV) at 4 weeks (DeltaLVEDV) was defined as LV remodeling (>20% increase from baseline). RESULTS: Patients were divided into two groups according to LV remodeling status: the remodeling group (n = 41) and the nonremodeling group (n = 39). There was a significant difference in the magnitude of CV between the two groups (5.11 +/- 1.47 vs 5.96 +/- 189 dB, P < .05), and the NTD was significantly different in the two groups (1.57 +/- 0.31 vs 1.23 +/- 0.32, P < .0001). The correlation between the magnitude of CV and DeltaLVEDV was significant but weak (r = -0.338, P < .01). There was significant correlation between NTD and DeltaLVEDV (r = 0.443, P < .0001). Using NTD greater than 1.35 as the optimal cutoff, the sensitivity, specificity, and positive and negative predictive values to predict LV remodeling were 82%, 86%, 87%, and 80%, respectively. CONCLUSIONS: Myocardial IBS, especially NTD, is useful for predicting LV remodeling in patients with AMI after primary coronary angioplasty.

Left ventricular free wall rupture in transient left ventricular apical ballooning.

A 79-year-old woman presented with chest pain. Her symptoms, combined with the results of an electrocardiogram, echocardiogram and laboratory investigations were compatible with an extensive acute anterior myocardial infarction. However, emergency coronary angiography showed no stenotic lesion in any coronary artery, but left ventriculography revealed apical ballooning akinesis and basal hyperkinesis and she was diagnosed as having transient left ventricular apical ballooning. After 7 days, she suddenly went into cardiopulmonary arrest because of cardiac tamponade. The autopsy revealed a free wall rupture. Generally, the prognosis in transient left ventricular apical ballooning is good; left ventricular free wall rupture is very rare.

Impact of hydroxymethylglutaryl coenzyme A reductase inhibition on left ventricular remodeling in patients with acute anterior myocardial infarction after primary coronary angioplasty.

Hydroxymethyglutaryl coenzyme A reductase inhibition (statin) therapy has been shown to reduce cardiac hypertrophy in vitro and in vivo. We assessed the influence of short-term statin therapy on left ventricular (LV) remodeling after acute myocardial in-farction. Thirty-five patients with first anterior acute myocardial infarction, who underwent primary coronary angioplasty within 12 hours of onset, were divided into 2 groups. Ten patients taking statin served as the statin group, and 25 patients not taking statin served as the control group. Two-dimensional echocardiography was recorded after angioplasty (baseline) and at 4 weeks. LV ejection fraction (LVEF) at baseline was not significantly different between the 2 groups. However, the statin group had a higher LVEF at 4 weeks than the control group (58.2 +/- 5.0 versus 49.0 +/- 12.7%; P < 0.05). Moreover, the increase in LV end-diastolic volume (LVEDV) at 4 weeks was lower in the statin group than in the control group (12.1 +/- 29.6 versus 39.9 +/- 35.7 mL; P < 0.05). Multiple regression analysis demonstrated that administration of statin was an independent factor for the increase in LVEDV (P < 0.05). These findings indicate that short-term statin therapy can prevent postinfarct LV remodeling and improve LV function.

Usefulness of coronary flow reserve immediately after primary coronary stenting in predicting wall motion recovery in patients with anterior wall acute myocardial infarction.

This study examined whether coronary flow reserve (CFR) measured immediately after primary coronary stenting could predict wall motion recovery in patients who have acute myocardial infarction. CFR significantly correlated with the change of wall motion score (r = 0.68, p <0.0001), and the optimal cut-off value of CFR for predicting wall motion recovery was 1.4 (sensitivity 85%, specificity 94%).

Primary cardiac tumor presenting as obstruction of the left ventricular outflow tract.

A transthoracic echocardiogram revealed 3 tumors in the left atrium of a 64-year-old woman, who died suddenly 8 months after resection of the tumors. Primary cardiac tumors are unusual and a case of postoperative left ventricular metastases of the atrial tumors resulting in left ventricular outflow tract obstruction is very rare occurrence.

Specific findings of the standard 12-lead ECG in patients with 'Takotsubo' cardiomyopathy: comparison with the findings of acute anterior myocardial infarction.

The clinical course of 'Takotsubo' cardiomyopathy closely resembles that of acute myocardial infarction (AMI) and coronary angiography (CAG) is usually performed to distinguish the 2 conditions during the acute phase. The present study was designed to determine whether the standard 12-lead electrocardiogram (ECG) findings could help to distinguish 'Takotsubo' cardiomyopathy from anterior AMI. The study group comprised 13 patients with 'Takotsubo' cardiomyopathy and 13 consecutive patients with anterior AMI. Patients with 'Takotsubo' cardiomyopathy had abnormal Q waves less frequently than patients with anterior AMI (15% vs 69%, p=0.008). No reciprocal changes were seen in the inferior leads in patients with 'Takotsubo' cardiomyopathy (p=0.0003). The ratio of ST-segment elevation in leads V(4-6) to V(1-3) (SigmaSTeV(4-6)/V(1-3)) was significantly higher in patients with 'Takotsubo' cardiomyopathy (1.55+/-0.53 vs 0.57+/-0.58, p=0.0004). The QTc interval was significantly longer in patients with 'Takotsubo' cardiomyopathy. The absence of reciprocal changes, absence of abnormal Q waves, and a SigmaSTeV(4-6)/V(1-3) >/=1 all showed a high sensitivity and specificity for diagnosing 'Takotsubo' cardiomyopathy. Furthermore, the combination of the absence of reciprocal changes and a SigmaSTeV(4-6)/V (1-3) >/=1 had a greater specificity (100%) and overall accuracy (91%) than either criteria. Therefore, the standard 12-lead ECG on admission can help to distinguish 'Takotsubo' cardiomyopathy from anterior AMI.

Influence of diabetes mellitus on outcome in the era of primary stenting for acute myocardial infarction.

The purpose of the present study was to examine the influence of diabetes mellitus (DM) on the clinical and angiographic outcomes in 62 diabetic and 152 nondiabetic patients with acute myocardial infarction (AMI) treated with primary coronary stenting within 12 h of the onset of symptoms. The diabetic patients had a greater incidence of hyperlipidemia, prior myocardial infarction (MI) and multivessel disease. There were no statistically significant differences in other variables. Procedural success was similar in the 2 groups. At a mean follow-up of 2.1 +/- 0.6 years, 13% of diabetic and 11% of nondiabetic patients had died (p = 0.70). The percentage of target vessel revascularization (TVR) was 37% of diabetic and 20% of nondiabetic patients (p = 0.003). Rates of major adverse cardiac events (MACE: death, non-fatal MI, TVR) were 50% of diabetic and 32% of nondiabetic patients (p = 0.007). On multivariate analysis, DM was not a predictor of death. Independent predictors of death were age, multivessel disease, TIMI < or = 2 and cardiogenic shock. However, DM and age were independent predictors of MACE. In conclusion, DM is not an independent predictor of death in patients with AMI after stenting, but diabetic patients had a higher incidence of TVR, making DM an independent predictor of MACE.