Distal myocardial protection during percutaneous coronary intervention with an intracoronary beta-blocker

Periprocedural Myocardial Injury: Pathophysiology, Prognosis, and Prevention

The definition and clinical implications of myocardial infarction occurring in the setting of percutaneous coronary intervention have been the subject of unresolved controversy. The definitions of periprocedural myocardial infarction (PMI) are many and have evolved over recent years. Additionally, the recent advancement of different imaging modalities has provided useful information on a patients' pre-procedural risk of myocardial infarction. Nonetheless, questions on the benefit of different approaches to prevent PMI and their practical implementation remain open. This review aims to address these questions and to provide a current and contemporary perspective.

Effect of Vitamin D in the Prevention of Myocardial Injury Following Elective Percutaneous Coronary Intervention: A Pilot Randomized Clinical Trial

Myocardial injury following elective percutaneous coronary intervention (PCI) occurs in about one-third of patients and is associated with mortality. Platelet aggregation, thrombosis formation, and inflammation are the main causes of cardiac injury during PCI. Vitamin D plays a key role in the cardiovascular system by exerting antiplatelet, anticoagulant, and anti-inflammatory properties. There is no published study that investigated the effect of vitamin D in the prevention of cardiac injury following elective PCI. In a randomized clinical trial, 99 patients admitted for elective PCI were randomized into vitamin D (n = 52) and control (n = 47) groups. The intervention group received 300 000 IU vitamin D orally 12 hours before PCI. The cardiac biomarkers were checked at baseline, 8 and 24 hours after PCI. hs-CRP was also measured at baseline and after 24 hours. The increase in CK-MB was documented in 20 patients (42%) in the control group and 18 patients (34.6%) in the intervention group (P = .417). Furthermore, the increase in cTnI occurred in 4 patients (8%) and 2 patients (3.3%) in the control and intervention groups, respectively (P = .419). No significant changes were noted in the level of cardiac biomarkers. In the vitamin D group, the mean difference in CK-MB between 8 and 24 hours was significantly lower (P = .048). The mean difference in hs-CRP was significantly lower in the vitamin D group (P = .045). This study could not show a clear effect of vitamin D in the prevention of cardiac injury during elective PCI. Further outcome-based studies are needed to describe the role of vitamin D in the prevention of periprocedural myocardial injury.

Cardioprotective Effects of Nicorandil on Coronary Heart Disease Patients Undergoing Elective Percutaneous Coronary Intervention

Background

Nicorandil is a nicotinamide ester commonly prescribed for treatment of patients with coronary heart disease (CHD). In the present study, we aimed to explore the cardioprotective effects of nicorandil on CHD patients undergoing elective percutaneous coronary intervention (PCI).

Material/Methods

One hundred patients with CHD undergoing PCI were randomly divided into a control group (n=48) and a nicorandil group (n=52). Patients in the control group received traditional therapy, and while patients in the nicorandil group received nicorandil before PCI in addition to the traditional therapy. After PCI, all patients underwent coronary angiogram, and TIMI frame count (TFC) was calculated. Plasma levels of cardiac troponin I (cTnI), creatine kinase-MB (CK-MB), myeloperoxidase (MPO), and malondialdehyde (MDA) were determined before and at 6, 18, and 24 h after PCI. Moreover, systolic blood pressure (SBP), mean blood pressure (DBP), heart rate (HR), and left ventricular ejection fractions (LVEF) were recorded before and 3 months after PCI.

Results

There was a significant difference in the rate of no-reflow (P=0.036) between the 2 groups. The blood frames and levels of cTnI, CK-MB, MPO, and MDA in the nicorandil group were significantly decreased compared to the control group (all P<0.05). Moreover, administration of nicorandil markedly decreased SBP, MBP, and HR, but obviously increased LVEF at 3 months after PCI (P<0.05 or P<0.01).

Conclusions

Nicorandil exerts cardioprotective effects on CHD patients undergoing elective PCI by decreasing PCI-related myocardial injury and rate of no-reflow and improvement of LVEF.

The randomized clinical trial of coenzyme Q10 for the prevention of periprocedural myocardial injury following elective percutaneous coronary intervention

INTRODUCTION

Periprocedural myocardial injury (PMI) following elective percutaneous coronary intervention (PCI) is an important therapeutic concern with remaining some mortality and morbidity. To the best of our knowledge, there is no published study that investigates the potential benefit of CoQ10 in preventing PMI following elective PCI.

METHODS

In a randomized, clinical trial, 100 patients who scheduled for elective PCI were allocated in to the intervention (n=50) and control group (n=50). The intervention received a 300 mg loading dose CoQ10 12 hours before procedure. The level of CK-MB and troponin-I was measured before procedure, and 8 and 24 hours after. Furthermore, hs-CRP was measured at baseline and 24 hours after. All patients were assessed for the incidence of major adverse cardiac effects (MACEs) after 1 month.

RESULTS

The CK-MB elevation (above the upper limit normal) was occurred in 22% (n=11) of CoQ10 and 20% (n=10) of control (P=.806). The elevation of troponin-I was documented in 8% (n=4) of both groups. No significant change in the level of cardiac biomarkers was noted. However, the significant reduction in hs-CRP level was occurred in CoQ10 group (P=.032).

CONCLUSION

The results showed that pretreatment with 300 mg CoQ10 12 hours before procedure could not reduce PMI following elective PCI, however, significantly decreased hs-CRP.

Association of chronic kidney disease with periprocedural myocardial injury after elective stent implantation: A single center prospective cohort study

Coronary artery disease (CAD) is the leading cause of mortality in patients with chronic kidney disease (CKD). Patients with CKD who undergo percutaneous coronary intervention (PCI) may have more ischemic events than patients without CKD. The aim of our study was to determine the incidence of periprocedural myocardial injury (PMI) after elective stent implantation in patients with CKD using the Third Joint ESC/ACCF/AHA/WHF PMI definition.In a single center prospective cohort study, we enrolled 344 consecutive patients who underwent elective PCI in a period of 39 months. Serum troponin I (cTnI) concentrations were measured at baseline and at 8 and 16 hours after PCI. Periprocedural increase of cTnI, according to the most recent PMI definition, was used to define both the presence and intensity of PMI. Patients were further stratified according to the estimated glomerular filtration rate (eGFR) using 4 variable Modification of Diet in Renal Disease (MDRD) equation: control group with eGFR >90 mL/min/1.73 m and the CKD group with eGFR < 90 mL/min/1.73 m, with further subdivision according to the CKD stage.We found no significant difference in the incidence as well as intensity of the PMI in the control (>90 mL/min/1.73 m) and the CKD group (<90 mL/min/1.73 m) both 8 and 16 hours after PCI. When the CKD patients were further subdivided according to their CKD stage, there was again no difference in the intensity or incidence of PMI compared to the control group. Further analyses of our data showed angina pectoris CCS IV, bare metal stent (BMS) implantation, and treatment with angiotensin-converting enzyme inhibitors (ACEI) as independent predictors of PMI. Furthermore, the presence of hypertension was inversely related to the occurrence of PMI.Applying the new guidelines for PMI and using the eGFR equation most suitable for our patients, we found no association between PMI and CKD. Further analyses showed other factors that could potentially influence the occurrence of PMI.

Predictors and Prognostic Significance of Troponin-I Release following Elective Coronary Angioplasty

The objective of this study was to investigate the predictors and prognostic significance of post-procedural cardiac troponin (cTn)-I elevations in a consecutive series of patients who underwent elective percutaneous coronary intervention (PCI). cTn-I was measured in 100 patients immediately before and within 24 h after the elective PCI. Post-procedural cTn-I elevation was observed in 27 of the 100 patients. In multivariate analysis, basal haemoglobin values and the number of repeated balloon dilatations were found to be independent predictors of cTn-I elevation. During the follow-up period of 12 ± 1.2 months, the cTn-I-positive group had more major adverse cardiovascular events than the cTn-I-negative group (33.3% versus 16.4%, respectively), but the difference was not significant. An increase in cTn-I levels following elective PCI procedures was frequent but did not predict a poor long-term outcome.

ST-segment elevation on intracoronary electrocardiogram after percutaneous coronary intervention is associated with worse outcome in patients with non-ST-segment elevation myocardial infarction

OBJECTIVES

We sought to examine whether intracoronary electrocardiogram (IC-ECG) assessment in patients with non-ST-segment elevation myocardial infarction (NSTEMI) can predict cardiac outcomes.

BACKGROUND

There has been no data correlating myocardial damage and cardiac events with an IC-ECG ST-segment change after percutaneous coronary intervention (PCI) in NSTEMI patients.

METHODS

We examined 111 NSTEMI patients undergoing PCI with an IC-ECG recording. IC-ECG ST-segment elevation (STE) was defined as >0.1 mV in the risk area, located by placing the guidewire distal to the culprit lesion. Clinical characteristics and in-hospital and long-term follow-up adverse cardiac event rates were compared between IC-ECG STE and non-IC-ECG STE groups at the completion of PCI.

RESULTS

IC-ECG STE was observed in 36 patients (32.4%) immediately after PCI. Peak cardiac biomarkers were significantly elevated in patients with IC-ECG STE versus those without (cardiac troponin I 31.9 ng/mL (18.0-104.5) vs. 8.2 ng/mL (1.8-21.4); P < 0.001). At a median follow-up of 35 months, the cardiac event free rate was significantly worse in patients with IC-ECG STE than in those without (long-rank test χ(2) = 10.9; P = 0.001). Cox proportional hazards analysis showed IC-ECG STE (hazard ratio, 2.54; 95% confidence interval [CI], 1.38-4.70; P = 0.003) was an independent predictors of cardiac events.

CONCLUSIONS

The present study suggests that presence of IC-ECG STE might help identify high-risk NSTEMI patients with greater myocardial injury leading to adverse cardiac events.

Efficacy of electroacupuncture pretreatment for myocardial injury in patients undergoing percutaneous coronary intervention: A randomized clinical trial with a 2-year follow-up

Electroacupuncture pretreatment (EAP) safely protects the heart from ischemic injury, however, the efficacy of EAP for periprocedural myocardial injury after percutaneous coronary intervention (PCI) remains unclear. Our aim was to investigate whether EAP prior to PCI reduces post-PCI myocardial injury in patients with coronary artery disease (CAD). 388 patients (≥ 18 years old) with CAD, undergoing elective PCI were enrolled and randomized, out of those 204 went through the whole trial. EAP was conducted by 30-minute electrical stimulation through 4 electrodes attached to the Antiguan (PC6) and Ximen (PC4) acupoints in the forearm bilaterally 1-2h prior to PCI. The control group had sham electrodes but no electrical stimulation. The primary end point was the incidence of myocardial infarction type 4a (MI4a) based on serum cTnI values at 24h after PCI. The secondary end points included post-procedural cardiac function and the major adverse cardiac/cerebrovascular event (MACCE) rate. EAP prior to PCI significantly reduced the incidence of MI4a (serum cTnI≥0.20 ng/mL) 24h post-PCI compared to the control group (P=0.004). The echocardiography at 6 months after PCI revealed significant improvement in cardiac function in the EAP group compared with the control group. The MACCE rate was significantly decreased in the EAP group at 24 month follow-up compared to the control group (P=0.0157). Moreover, multivariate logistic regression analysis showed that EAP was associated with decreased likelihood of MACCE (odds ratio 0.327, 95% CI 0.140-0.767, P=0.010). EAP prior to PCI significantly reduced cTnI release and protected patients with CAD from subsequent myocardial injury after PCI procedure.

Myocardial Injury after Percutaneous Coronary Intervention for In-Stent Restenosis Versus de novo Stenosis

OBJECTIVE

Periprocedural myocardial injury (PMI) remains a relatively common complication even after successful procedures. In-stent restenosis (ISR) may be involved in lesion-related factors for PMI. We compared the incidence of PMI between patients with ISR and those with de novo stenosis.

METHODS

The study population consisted of 121 patients with coronary artery disease who had been treated with statins and subsequently underwent angiographically successful percutaneous coronary intervention (PCI). Blood samples for troponin I were collected 18 to 24 hours after PCI. PMI was defined as an increase in the troponin I levels greater than 0.15 ng/mL. Major PMI was defined as an increase in the troponin I levels greater than 0.75 ng/mL.

RESULTS

There were 34 patients with ISR and 87 patients with de novo stenosis. The incidence of PMI was similar between the two groups (47.1 % vs. 55.2 %, p=0.42). Among the patients with ISR, the incidences of PMI were 33.3 %, 60.0 % and 66.7 % in patients with focal ISR, diffuse ISR and diffuse proliferative ISR, respectively, although these differences were not statistically significant. The incidence of major PMI was significantly less frequent in patients with ISR than those with de novo stenosis (5.9 % vs. 25.3 %, p=0.03). A multivariate logistic regression analysis showed that ISR [odds ratio (OR) 0.22, 95% confidence interval (CI) 0.03-0.90; p=0.03] and the maximum inflation pressure (OR 1.15, 95% CI 1.04-1.30; p=0.009) were independent predictors of major PMI.

CONCLUSION

Our results suggest that while PMI occurs in patients with ISR as commonly as those with de novo stenosis, major PMI occurs less frequently in patients with ISR.

A pilot randomized trial of pentoxifylline for the reduction of periprocedural myocardial injury in patients undergoing elective percutaneous coronary intervention

PURPOSE

Periprocedural myocardial injury (PMI) following percutaneous coronary intervention (PCI) has received great attention due to its significant association with mortality and morbidity. Accordingly, cardioprotection during PCI is one of the important therapeutic concerns. Regarding the potential cardiovascular benefits of pentoxifylline this study was performed to evaluate whether the pretreatment pentoxifylline could reduce PMI in patients who are undergoing elective PCI.

METHODS

A randomized clinical trial on 85 patients undergoing elective PCI was performed. The intervention group (n = 41) received 1200 mg pentoxifylline in divided doses plus the standard treatment before PCI, while the control group (n = 44) received the standard treatment. For assessing myocardial damage during PCI, the levels of CK-MB and troponin-I were measured at baseline, 8, and 24 h after the procedure. Then, patients were followed up for a 1-month period regarding the major adverse cardiac effect.

RESULTS

Comparing with the control group, no significant change of CK-MB at 8 (p = 0.315) and 24 h (p = 0.896) after PCI was documented in pentoxifylline group. Similarly, no significant change was found in troponin-I at 8 (p = 0.141) and 24 h (p = 0.256) after PCI.

CONCLUSIONS

This study could not support the pretreatment with pentoxifylline in the prevention of PMI in patients undergoing elective PCI. However, the trend was toward the potential benefit of pentoxifylline.

Effect of metoprolol on myocardial apoptosis after coronary microembolization in rats

BACKGROUND

Coronary microembolization (CME) is a serious complication following percutaneous coronary intervention (PCI) in patients with acute coronary syndromes. The use of metoprolol before PCI can significantly protect ischemic myocardium from myocardial damage, but the function of metoprolol in the treatment of CME is not entirely clear. This study was to explore the effect and significance of metoprolol on myocardial apoptosis and caspase-3 activation after CME in rats.

METHODS

Thirty rats were randomly divided into three groups including sham-operation (control group), CME plus saline (CME group), CME plus metoprolol (metoprolol group), 10 rats for each group. The CME group was induced by injecting 3 000 polyethylene microspheres (42 μm) into the left ventricle during a 10-second occlusion of the ascending aorta; the control group was injected with physiological saline instead of microembolization ball; the metoprolol or saline group was given three intravenous bolus injections before CME. Echocardiography, TUNEL staining, and Western blotting were used to evaluate cardiac function, proportion of apoptotic cells and activation of caspase-3 respectively at 6 hours after operation.

RESULTS

Echocardiographic parameters displayed that the metoprolol group improved cardiac function significantly compared with the CME group (P<0.05). The myocardial apoptotic rate of the CME group as well as the contents of activated caspase-3 increased significantly (P<0.05), both of which were ameliorated significantly by metoprolol treatment (P<0.05).

CONCLUSIONS

This study demonstrates that metoprolol can protect the myocardium during CME in rats by inhibiting apoptosis and improving cardiac function. These results suggest that the inhibition of apoptosis can be a potential therapeutic strategy for the treatment of CME.

Cardioprotective effects of single oral dose of nicorandil before selective percutaneous coronary intervention

Objective:

Nicorandil, an opener of ATP-sensitive K+ channels, was used to treat angina in patients with coronary artery disease. In this study, we aim to investigate the cardioprotective effects of single oral dose of nicorandil in patients undergoing selective percutaneous coronary intervention (PCI).

Methods:

One hundred and thirty-eight patients with acute coronary syndrome undergoing PCI from July 2011 to October 2012 were randomly divided into control group (group 1, n=47), 10 mg oral nicorandil group (group 2, n=45), and 20 mg oral nicorandil group (group 3, n=46) about 2 hours before procedure, respectively. Cardiac troponin I (cTnI) levels were determined at 20 ~ 24 hours after PCI.

Results:

There was a significant difference in the rate of any cTnI elevation among the three groups (group 1: 36.17%, group 2: 20.00%, group 3: 15.22%, p=0.0176). With respect to the frequency of cTnI elevation ≥3 and 5×the upper limit of normal (ULN), there also had statistical difference among the three groups (17.02% in group 1, 8.89% in group 2, and 4.35% in group 3, respectively for cTnI elevation ≥3× ULN, p=0.0428; 12.77% in group 1, 6.67% in group 2, and 2.17% in group 3, respectively, for cTnI elevation ≥5× ULN, p=0.0487). Logistic regression analysis showed that LVEF (OR=0.915, 95% CI=0.853-0.981) and the use of nicorandil (OR=0.516, 95% CI=0.267-0.996) before PCI were independent protective factors of myocardial injury.

Conclusion:

Single oral dose of nicorandil (10 mg, 20 mg) 2 hours before the PCI procedure could decrease the incidence of peri-procedure myocardial injury and PCI-related myocardial infarction.

Usefulness of rosuvastatin to prevent periprocedural myocardial injury in patients undergoing elective coronary intervention

The aim of the present study was to investigate whether percutaneous coronary intervention-related periprocedural myocardial infarction (MI) can be suppressed more significantly with high- compared with low-dose rosuvastatin. A total of 232 patients scheduled to undergo elective percutaneous coronary intervention within 5 to 7 days were assigned to groups that would receive either 2.5 or 20 mg/day of rosuvastatin (n = 116 each). The incidence of periprocedural MI did not significantly differ between the high and low-dose groups (8.7% vs 18.7%, p = 0.052). In patients who were not taking statins at the time of enrollment, high-dose rosuvastatin significantly suppressed periprocedural MI compared with the low dose (10.5% vs 30.0%, p = 0.037). The difference was not significant in patients who were already taking statins (high vs low dose 7.6% vs 10.6%, p = 0.582). In conclusion, the incidence of percutaneous coronary intervention-related periprocedural MI was reduced more effectively by high-dose than by low-dose rosuvastatin in statin-naive patients. However, low-dose rosuvastatin is sufficient for patients who are already taking statins.

Suppression of Myocardial Injury Markers following Percutaneous Coronary Interventions by Pre-treatment with Carvedilol

BACKGROUND

Retrospective studies and clinical trials have indicated that β-receptor blockers have an influential role in improving survival and reducing risk of recurrent infarction in patients with myocardial infarction. However, there is still controversy regarding the effects of β-receptor blockers on the markers of myocardial infarction following percutaneous coronary interventions (PCI).

OBJECTIVE

The aim of this study was to evaluate the pre-treatment effect of Carvedilol on markers of myocardial injury in patients undergoing elective PCI.

METHOD AND MATERIALS

In this clinical trial patients undergoing elective PCI were categorized randomly in the Carvedilol group including 100 patients who received two doses of 12.5 mg, 6 and 12 hours prior to PCI, and the control group (105 patients). Blood samples were obtained to analyse cardiac biomarker, 12 and 24 hours after PCI.

RESULTS

The clinical features were not significantly different between the two groups. A increase in the level of Troponin I was observed in the control group 24 hours following PCI (P=0.042), whereas this rise in troponin I was slight and insignificant in the Carvedilol group (P>0.05). some difference was observed between the two groups in regard to the level of CPK-MB after PCI (P=0.041).

CONCLUSION

The findings of our study indicate that pre-treatment with Carvedilol confers cardio-protection by limiting the rise of markers of myocardial injury following PCI.

Intracoronary followed by intravenous administration of the short-acting β-blocker landiolol prevents myocardial injury in the face of elective percutaneous coronary intervention

BACKGROUND

Myocardial injury during elective percutaneous coronary intervention (PCI) is associated with higher subsequent cardiac events and mortality. β-Blockers have been used to reduce myocardial injury during ischemia and reperfusion. We investigated whether intracoronary followed by intravenous administration of the short-acting β-blocker landiolol prevents myocardial injury in the face of elective PCI.

METHODS AND RESULTS

Patients undergoing elective PCI (n=70) were randomly assigned to the landiolol (n=35) or control (n=35) group. Landiolol or saline was administered into target vessels through a balloon catheter for 1min before and after first balloon inflation followed by continuous intravenous administration for 6h after PCI. The incidence of myocardial injury defined by cardiac troponin-I (cTnI) >/=0.05 ng/ml was 79% of the patients in the control group compared to 56% in the landiolol group (p=0.04). The cTnI level at 24h after PCI tended to be lower in the landiolol group (0.57 ± 1.14 versus 1.27 ± 2.48 ng/ml; p=0.07), while the CK-MB level was not significantly different between the landiolol and control groups. The incidence of peri-procedural myocardial infarction defined by cTnI >/=0.12 ng/ml was significantly (p=0.02) lower in the landiolol group (41%) compared to the control group (70%). There was no incidence of coronary spasm, hypotension, bradycardia or heart failure during and after PCI in the two groups.

CONCLUSIONS

Brief intracoronary followed by continuous intravenous administration of landiolol is safe and effective for myocardial protection in the face of elective PCI.

Pharmacological prevention of peri-, and post-procedural myocardial injury in percutaneous coronary intervention

In recent years, percutaneous coronary intervention (PCI) has become a well-established technique for the treatment of coronary artery disease. PCI improves symptoms in patients with coronary artery disease and it has been increasing safety of procedures. However, peri- and post-procedural myocardial injury, including angiographical slow coronary flow, microvascular embolization, and elevated levels of cardiac enzyme, such as creatine kinase and troponin-T and -I, has also been reported even in elective cases. Furthermore, myocardial reperfusion injury at the beginning of myocardial reperfusion, which causes tissue damage and cardiac dysfunction, may occur in cases of acute coronary syndrome. Because patients with myocardial injury is related to larger myocardial infarction and have a worse long-term prognosis than those without myocardial injury, it is important to prevent myocardial injury during and/or after PCI in patients with coronary artery disease. To date, many studies have demonstrated that adjunctive pharmacological treatment suppresses myocardial injury and increases coronary blood flow during PCI procedures. In this review, we highlight the usefulness of pharmacological treatment in combination with PCI in attenuating myocardial injury in patients with coronary artery disease.

Relation between the presence and extent of coronary lipid core plaques detected by near-infrared spectroscopy with postpercutaneous coronary intervention myocardial infarction

We aimed to examine whether an association exists between the presence and extent of coronary lipid core plaques (LCPs) detected by near-infrared spectroscopy (NIRS) performed before percutaneous coronary intervention (PCI) with postprocedural myocardial infarction (MI). NIRS was performed in the native coronary arteries of 30 patients before PCI. Angular extent of LCP, lesion segment lipid core burden index, and block chemogram were evaluated. Cardiac biomarkers were measured before and 16 to 24 hours after PCI to determine occurrence of postprocedural MI. Mean number of 2-mm yellow blocks within the stented lesion was 1.4 ± 2.1 and mean lesion lipid core burden index was 110.3 ± 99. Using a definition of creatine kinase-MB >1 time upper limit of normal (ULN), >2 times ULN, and >3 times ULN, MI after PCI occurred in 23%, 13%, and 10% of patients, respectively. Compared to patients who did not have MI after PCI, those who did had similar clinical characteristics but received more stents and had more blocks within the stented lesion. Creatine kinase-MB increase >3 times ULN was observed in 27% of patients with ≥1 yellow block versus in none of the patients without a yellow block within the stented lesion (p = 0.02). In conclusion, PCI of LCP-positive lesions as assessed by NIRS is associated with increased risk for MI after PCI. NIRS may allow lesion-specific risk stratification before PCI and optimization of PCI strategies for myocardial injury risk minimization.

Clinical benefit of statin pretreatment in patients undergoing percutaneous coronary intervention: a collaborative patient-level meta-analysis of 13 randomized studies

BACKGROUND

Previous studies suggested that statin pretreatment reduces cardiac events in patients undergoing percutaneous coronary intervention. However, most data were observational, and single randomized trials included limited numbers of patients.

METHODS AND RESULTS

We performed a collaborative meta-analysis using individual patient data from 13 randomized studies in which 3341 patients received either high-dose statin (n=1692) or no statin/low-dose statin (n=1649) before percutaneous coronary intervention, with all patients receiving statin therapy after intervention. Occurrence of periprocedural myocardial infarction, defined as postintervention creatine kinase-MB increase ≥3 times the upper limit of normal, and 30-day major adverse cardiac events (death, myocardial infarction, target-vessel revascularization) was evaluated. Incidence of periprocedural myocardial infarction was 7.0% in the high-dose statin versus 11.9% in the control group, which corresponds to a 44% risk reduction in the active-treatment arm (odds ratio by fixed-effects model 0.56, 95% confidence interval, 0.44 to 0.71, P<0.00001). The rate of major adverse cardiac events at 30 days was significantly lower in the high-dose statin group (7.4% versus 12.6%, a 44% risk reduction; P<0.00001), and 1-month major adverse cardiac events, excluding periprocedural events, were also reduced (0.6% versus 1.4%; P=0.05). The benefit of high-dose statins was realized irrespective of clinical presentation (P for interaction=0.43) and was maintained across various subgroups but appeared greater in the subgroup with elevated baseline C-reactive protein levels (n=734; 68% risk reduction for periprocedural myocardial infarction versus 31% in those 1861 patients with normal CRP; P for quantitative interaction=0.025).

CONCLUSIONS

High-dose statin pretreatment leads to a significant reduction in periprocedural myocardial infarction and 30-day adverse events in patients undergoing percutaneous coronary intervention. This strategy should be considered in all patients with planned percutaneous coronary intervention.

Beta blocker metoprolol protects against contractile dysfunction in rats after coronary microembolization by regulating expression of myocardial inflammatory cytokines

AIMS

To examine the effects of metoprolol on expression of myocardial inflammatory cytokines and myocardial function in rats following coronary microembolization (CME).

MAIN METHODS

Male rats were randomly assigned to receive either sham-operation (control group), CME plus saline (CME group), or CME plus metoprolol (metoprolol group). CME was induced by injecting 3000 polyethylene microspheres (42 μm) into the left ventricle during a 10-second occlusion of the ascending aorta. Metoprolol (2.5mg/kg) or saline was administered as three intravenous bolus injections after CME. At 3h, 6h, 12h, 24h and 4 weeks after CME, myocardial function was measured with echocardiography; and the mRNA and protein levels of tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10) and interleukin 1-β (IL-1β) were determined.

KEY FINDINGS

Induced CME led to markedly higher mRNA and protein levels of TNF-α, IL-1β and IL-10 at 3, 6, 12, and 24h, as well as reduced left ventricular function, compared to the control group. Metoprolol administration reduced TNF-α and IL-1β levels, but increased IL-10 levels at 3, 6, 12, and 24h compared to the CME group. Moreover, metoprolol treatment resulted in significantly improved left ventricular function at 12h, 24h and 4 weeks, but afforded no cardiac protection at 3h and 12h, compared to the CME group.

SIGNIFICANCE

Higher levels of TNF-α and IL-1β in rats following CME are associated with the development of myocardial contractile dysfunction. Metoprolol-conferred protection against progressive contractile dysfunction following CME may be mediated by its anti-inflammation potential.

Peri-procedural myocardial injury during percutaneous coronary intervention: an important target for cardioprotection

Percutaneous coronary intervention (PCI) has become the predominant procedure for coronary revascularization in patients with both stable and unstable coronary artery disease (CAD). Over the past two decades, technical advances in PCI have resulted in a better and safer therapeutic procedure with minimal procedural complications. However, about 30% of patients undergoing elective PCI sustain myocardial injury arising from the procedure itself, the extent of which is significant enough to carry prognostic importance. The peri-procedural injury which accompanies PCI might therefore reduce some of the beneficial effects of coronary revascularization. The availability of more sensitive serum biomarkers of myocardial injury such as creatine phosphokinase MB isoenzyme (CK-MB), Troponin T, and Troponin I has enabled the quantification of previously undetectable myocardial injury. Peri-procedural myocardial injury (PMI) can also be visualized by cardiac magnetic resonance imaging, a technique which allows the detection and quantification of myocardial necrosis following PCI. The identification of CAD patients at greatest risk of sustaining PMI during PCI would allow targeted treatment with novel therapies capable of limiting the extent of PMI or reducing the number of patients experiencing PMI.

Statin loading before percutaneous coronary intervention: proposed mechanisms and applications

Statin therapy reduces the risk of cardiovascular events in patients with coronary artery disease. Recent in vitro and in vivo studies demonstrated a LDL-independent action of these class of drugs, which appears in modulating endothelial function, inflammation and thrombosis. Periprocedural myocardial infarction and contrast-induced nephropathy after percutaneous coronary intervention (PCI), associated with worse outcome on long-term follow-up, are both complications related to inflammatory pathogenetic mechanisms. Randomized studies demonstrated a beneficial effect of short-term statin pretreatment in reducing periprocedural cardiac marker release in patients undergoing PCI. Statin therapy before elective PCI reduces periprocedural myocardial infarction in patients with stable angina. Furthermore, an acute loading with a high dose of atorvastatin prevents myocardial damage in patients with acute coronary syndromes undergoing early PCI (<48 h). In patients already on chronic statin therapy, a reload with high-dose statins was associated with a significant improvement on 30-day major adverse cardiac event rates. Furthermore, statin therapy at the time of PCI significantly decreased the incidence of contrast-induced nephropathy. This evidence suggests an ‘upstream administration’ of short-term, high-dose statins in all patients undergoing PCI.

Procedure-related myonecrosis after bare and drug-eluting stent implantation

We sought to compare the incidence of myonecrosis after elective implantation of bare metal stents with that of drug-eluting stents. The data of stable patients who were treated with stenting in a single native coronary artery were analyzed retrospectively. The stents used were bare metal in 119, sirolimus-eluting (Cypher Select Plus) in 119 patients, paclitaxel-eluting (Taxus Liberté) in 120, zotarolimus-eluting (Endeavor Sprint) in 122, and everolimus-eluting (Xience V) in 72. Endpoints included post-procedural myonecrosis (any elevation of creatine kinase-MB), myocardial infarction (creatine kinase-MB>3 times the upper limit of normal), and large myocardial infarction (creatine kinase-MB>5 times the upper limit of normal). The incidences of myonecrosis (16.7%-18.9%), myocardial infarction (3.3%-8.4%), and large myocardial infarction (1.7%-5.6%) were not significantly different among stent types. At the 30-day follow-up, there were 2 deaths in patients who had Taxus Liberté stents, one death each in those with Xience V and bare metal stents, and no cases of stroke or target vessel revascularization. In this study, bare metal stents and the 4 drug-eluting stents were associated with similar low incidences of myonecrosis, myocardial infarction, and large myocardial infarction.

Microvascular obstruction after percutaneous coronary intervention

Successful revascularization of the epicardial coronary artery can be achieved in over 90% of percutaneous coronary intervention (PCI) procedures. However, postprocedural microvascular obstruction, despite the presence of normal epicardial flow, remains an important limitation which substantially reduces the beneficial effects of PCI. In this review article, a number of different methods available to diagnose microvascular obstruction after PCI are outlined. We also discussed the various pharmacological and mechanical strategies to reduce the occurrence of microvascular obstruction. In this regard, pretreatment with antiplatelet therapy remains crucial. In urgent PCI for acute myocardial infarction, available data suggest that manual thrombus aspiration device is beneficial in reducing the occurrence of procedure-related microvascular obstruction and possibly improve long-term clinical outcomes.

Minor myocardial damage during percutaneous coronary intervention does not affect long-term prognosis

INTRODUCTION AND OBJECTIVES

To determine whether long-term prognosis is affected by myocardial damage taking place during percutaneous coronary intervention (PCI).

METHODS

The study included consecutive patients undergoing PCI. Those with elevated baseline cardiac marker levels were excluded. Cardiac markers were evaluated and an ECG was recorded before and 12 and 24 hours after PCI. Patients were divided into three groups after PCI according to their cardiac marker levels: no myocardial damage (i.e. normal troponin and creatine kinase MB fraction [CK-MB]), minor damage (elevated troponin with normal CK-MB), and myonecrosis (elevated troponin and CK-MB). The occurrence of death, myocardial infarction or repeat revascularization during follow-up was recorded.

RESULTS

Minor myocardial damage associated with PCI was observed in 127 (16.8%) of the 757 patients included in the study and myonecrosis, in 46 (6.1%). During a follow-up of 45+/-14 months, cardiac events occurred in 151 (19.1%) patients. Mortality during follow-up was significantly higher in patients with myonecrosis (13%) than in the other two groups (4.8% and 3.9%; log rank, 6.83; P=.032). No difference was observed in the rate of myocardial infarction or repeat revascularization during follow-up.

CONCLUSIONS

Minor myocardial damage during PCI had no effect on long-term prognosis. In contrast, myonecrosis was associated with increased mortality. Consequently, the CK-MB level should be measured after all PCIs because of its prognostic implications, and strategies for reducing the risk of myonecrosis developing should be implemented.

The effects of prior calcium channel blocker therapy on creatine kinase-MB levels after percutaneous coronary interventions

Background:

Use of intracoronary calcium channel blockers (CCBs) during percutaneous coronary intervention (PCI) has been shown to have favorable effects on coronary blood flow. We aimed to investigate the effects of CCBs administrated perorally on creatine kinase-MB (CK-MB) levels in patients undergoing elective PCI.

Methods:

A total of 570 patients who underwent PCI were evaluated for CK-MB elevation. Patients who were on CCB therapy when admitted to the hospital constituted the CCB group. No CCBs were given to the rest of the patients during the periprocedural period and these patients served as the control group. Blood samples for CK-MB were obtained before and at 6 h, 24 h, and 36 h after the procedure.

Results:

217 patients were in the CCB group (mean age 60.2 ± 9.3 years, 162 males), and 353 were in the control group (mean age 60.0 ± 10.1 years, 262 males). CK-MB levels increased above the normal values in 41 patients (18.9%) of the CCBs group and in 97 patients (27.5%) of the control group (p = 0.02). Median CK-MB levels were significantly higher in the control group for all studied hours (for all p < 0.05).

Conclusions:

Prior oral CCB therapy may have favorable effects in preventing myocyte necrosis after elective PCI.

Troponin ratio and risk stratification in subjects with acute coronary syndrome undergoing percutaneous coronary intervention

BACKGROUND

Cardiac enzyme release after percutaneous coronary intervention (PCI) seems to play a role in risk stratification. After PCI, CK-MB plasmatic concentrations three times above the upper level of normal (ULN) are currently the most used risk stratification parameters. We sought to assess whether peak cardiac troponin I (cTn-I) concentration/base concentration ratio (PBTR) may act as a predictor of major adverse cardiac events (MACEs) after PCI, regardless of cTn-I ULN.

METHODS

We evaluated 326 consecutive patients with acute coronary syndrome (ACS) who underwent PCI. Baseline and post-PCI cTn-I values were evaluated over serial blood samples every 6h for at least 72h. Patients were further divided into four groups according to their PBTR values (<1, 1-4, 4-10, >10). MACEs were recorded over a 6-month follow-up period. Patients with primary PCI or unsuccessful PCI were excluded from the study.

RESULTS

Higher values of PBTR significantly correlated with a worse prognosis at 6 months (<1, 16.30% of MACEs; 1-4, 19.42%; 4-10, 24.39%; >10, 35.63%; p<0.05), both in Q-wave myocardial infarction (MI) and unstable angina (UA) subgroups. The correlation remained statistically significant, even considering subjects with peak cTn-I less than three times the ULN (p < 0.05) and after correction for age, gender, risk factors, diagnosis (MI versus UA), and peak cTn-I levels in a multiple Cox' regression analysis (HR 1.62, p<0.05).

CONCLUSIONS

PBTR is an independent predictor of MACEs after PCI in a 6-month follow-up period. This risk stratification tool may be useful to predict adverse events in PCI patients, even in the case of apparently non-elevated peak cTn-I concentrations.

[Myonecrosis and inflammatory response following percutaneous coronary angioplasty. A protective role for betablockers?]

INTRODUCTION

Percutaneous coronary intervention (PCI) is widely used actually for the treatment of coronary disease. Stent implantation in the vessel wall is associated with local healing processes and some myonecrosis. However, little is known about the relationships between systemic inflammatory response, myonecrosis and the patient's and procedural characteristics.

OBJECTIVES

(i) To evaluate the level of C-Reactive Protein (hsCRP) and cardiac troponin I (cTnI) elevation after PCI; (ii) to determine the patient's and procedural factors associated with those elevations.

METHOD

This is a prospective monocentric study carried out in patients hospitalised for elective PCI or for ACS without cTnI elevation. CRP and cTnI were assessed before, after and 24 hours after the procedure.

RESULTS

Thirty-four patients (mean age 64+/-10.9 years; sex ratio 28 males/six females) were included. hsCRP increased in 26 patients (76.4%) and cTnI in 16 patients (47%) after PCI. cTnI elevation did not correlate with inflammatory response. Whereas none of the studied parameters were statistically linked with hsCRP increase, cTnI elevation was significantly associated with AHA-ACC B(2)/C type lesion, the number and the total length of stents implanted, the duration of procedure and treatment by betablockers. Multivariate analysis showed that the independent predictors of cTnI elevation were procedure duration (p=0.032 OR=14.2 CI 95% 7.69-100) and the absence of pretreatment with betablockers (p=0.036, OR=2,6 CI 95% 1.35-35).

CONCLUSION

cTnI elevation following PCI is very frequent and related with the duration of the procedure. Our data suggest a protective role of betablockers in the occurrence of cTnI elevation after PCI. Confirmation of the protective role of betablockers in larger cohort is mandatory.

Review: Percutaneous coronary interventions and statins therapy

Statins exert a number of beneficial effects on endothelial function and atherosclerotic plaque, modulating oxidative stress and inflammation, with subsequent, well documented, primary and secondary prevention of coronary artery disease. Periprocedural myocardial infarction and contrast induced nephropathy, after percutaneous coronary intervention (PCI), are associated with a worse outcome on long term follow-up. In the ARMYDA study, pretreatment with statins before elective PCI reduces periprocedural myocardial infarction in patients with stable angina. Moreover, the ARMYDA ACS was the first randomized, prospective trial that demonstrated that an acute loading with a high dose of atorvastatin prevents myocardial damage in patients with unstable syndromes undergoing early ( <48 hours) coronary angiography and consequent angioplasty. Statins could also have beneficial effects by reducing expression of adhesion molecules in endothelial cells (ICAM-1 and E-Selectin) as demonstrated in the ARMYDA-CAMS study. Furthermore, patients receiving statins at the time of procedure show a significantly reduced incidence of contrast-induced nephropathy. All this evidence may strongly influence the clinical practice of an interventional cardiologist.

Preprocedural statin therapy in percutaneous coronary intervention

OBJECTIVE

To review the published literature regarding the effectiveness of preprocedural statin therapy for the prevention of cardiac events after percutaneous coronary intervention (PCI).

DATA SOURCES

Searches of MEDLINE (1966-May 2007) and Cochrane Database (1993-May 2007) were conducted using the search terms statins, HMG-CoA reductase inhibitors, percutaneous coronary intervention, and myocardial necrosis. Limits included articles written in English with human subjects. Additional data were identified through bibliographic reviews.

STUDY SELECTION AND DATA EXTRACTION

All English-language articles identified from the data sources were evaluated. Trials and studies were eligible for inclusion if they evaluated the effectiveness of preprocedural statin therapy for the prevention of cardiac events after PCI.

DATA SYNTHESIS

Hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) provide benefits relative to morbidity and mortality as primary and secondary prevention of cardiovascular events. In addition to lowering concentrations of low-density lipoprotein cholesterol, statins have documented pleiotropic effects including plaque stabilization as well as reductions in inflammation, platelet activation/adhesion, thrombosis, and oxidative stress. One retrospective analysis, 4 prospective observational studies, and 3 randomized controlled trials evaluating preprocedural statin therapy for the prevention of cardiac events after PCI were reviewed. Included studies were limited by small sample sizes (N = 153-5052), short durations of follow-up (24 h-21 mo), use of surrogate markers of myocardial necrosis, various degrees of coronary disease and procedure-specific factors, and lack of consistent choice of agent, dose, and duration of statin therapy. Despite these limitations, the data suggest reduced post-PCI myocardial necrosis with preprocedural statin therapy when given before elective PCI in stable patients, as well as when given before PCI in patients with recent acute coronary syndrome.

CONCLUSIONS

There is growing evidence that preprocedural statin therapy reduces the incidence of post-PCI myocardial necrosis. The appropriate regimen (drug, dose, duration of treatment before the procedure), as well as the predictive role of concomitant disease states (eg, hyperlipidemia), requires further investigation.

Early metoprolol administration before coronary reperfusion results in increased myocardial salvage: analysis of ischemic myocardium at risk using cardiac magnetic resonance

BACKGROUND

Beta-blockers improve clinical outcome when administered early after acute myocardial infarction. However, whether beta-blockers actually reduce the myocardial infarction size is still in dispute. Cardiac magnetic resonance imaging can accurately depict the left ventricular (LV) ischemic myocardium at risk (T2-weighted hyperintense region) early after myocardial infarction, as well as the extent of necrosis (delayed gadolinium enhancement). The aim of this study was to determine whether early administration of metoprolol could increase myocardial salvage, measured as the difference between the extent of myocardium at risk and myocardial necrosis.

METHODS AND RESULTS

Twelve Yorkshire pigs underwent a 90-minute left anterior descending coronary occlusion, followed by reperfusion. They were randomized to metoprolol (7.5 mg during myocardial infarction) or placebo. Global and regional LV function, extent of myocardium at risk, and myocardial necrosis were quantified by cardiac magnetic resonance imaging studies performed 4 and 22 days after reperfusion in 10 survivors. Despite similar extent of myocardium at risk in metoprolol- and placebo-treated pigs (30.9% of LV versus 30.6%; P=NS), metoprolol resulted in 5-fold-larger salvaged myocardium (32.4% versus 6.2% of myocardium at risk; P=0.015). The LV ejection fraction significantly improved in metoprolol-treated pigs between days 4 and 22 (37.2% versus 43.0%; P=0.037), whereas it remained unchanged in pigs treated with placebo (35.1% versus 35.0%; P=NS). The extent of myocardial salvage was related directly to LV ejection fraction improvement (P=0.031) and regional LV wall motion recovery (P=0.039) at day 22.

CONCLUSIONS

Early metoprolol administration during acute coronary occlusion increases myocardial salvage. The extent of myocardial salvage, measured as the difference between myocardium at risk and myocardial necrosis, was associated with regional and global LV motion improvement.

Detection of Coronary Microembolization by Doppler Ultrasound in Patients With Stable Angina Pectoris Undergoing Elective Percutaneous Coronary Interventions

Background— Intracoronary Doppler guidewires can be used for real-time detection and quantification of microembolism during percutaneous coronary interventions (PCIs). We investigated whether the frequency of Doppler-detected microembolism is related to the incidence of myonecrosis during elective PCI.

Methods and Results— The study population included 52 consecutive patients (aged 64±10 years; 36 men, 16 women) with coronary artery disease who underwent elective PCI of a single-vessel stenosis. Using intracoronary Doppler ultrasound, we compared the frequency of microembolism during PCI in 22 patients with periprocedural non–ST-segment elevation myocardial infarctions (pNSTEMI) and 30 patients without pNSTEMI. The 2 groups were comparable with regard to their clinical and procedural characteristics. In the group with pNSTEMI, the total number of coronary microemboli after PCI (27±10 versus 16±8, P <0.001) was higher than in the group without pNSTEMI. Although high-sensitivity C-reactive protein plasma levels were similar before PCI (2.9±2.2 versus 3.4±1.7 mg/L, P =NS), they were higher in the group with pNSTEMI after PCI (12.6±10.4 versus 6.1±5.1 mg/L, P <0.05). Microembolic count independently correlated to postprocedural cardiac troponin I elevation ( r =0.565, P <0.001), coronary flow velocity reserve ( r =−0.506, P <0.001), and baseline average peak velocity ( r =0.499, P <0.001).

Conclusions— Patients with pNSTEMI had a significantly higher frequency of coronary microembolization during PCI, and their systemic inflammatory response and microvascular impairment after PCI were more pronounced. Intracoronary Doppler ultrasound provides evidence that pNSTEMI in patients undergoing elective PCI is caused by microembolization during the procedure.

Randomized Trial of Statin Administration for Myocardial Injury

BACKGROUND

Minor myocardial damage after percutaneous coronary intervention (PCI) is associated with cardiac risks, which statins seem to reduce. The aim of this study was to examine whether intensive lipid-lowering therapy is more effective in decreasing the risk of cardiac injury after PCI than moderate lipid-lowering therapy.

METHODS AND RESULTS

Subjects comprised 42 patients with stable angina without previous statin treatment, randomly assigned to either an intensive lipid-lowering group (Group A: target low-density lipoprotein-cholesterol (LDL-C)<70 mg/dl) or a moderate lipid-lowering group (Group B: target LDL-C<100 mg/dl) 2 weeks before PCI. All patients took statins to reach target LDL-C levels. Incidence of periprocedural myocardial injury was assessed by analyzing levels of creatine kinase myocardial isozyme (CK-MB) and cardiac troponin T (TnT) before and 6, 12 and 24 h after PCI. Minor myocardial damage was defined as TnT elevation to >0.01 ng/ml. Frequency of minor myocardial damage was 14.2% in Group A and 47.6% in Group B (p=0.043). CK-MB was above the upper limit of normal (ULN) in 19% of Group A and 33.3% of Group B (p=0.44), and CK-MB was >3x ULN in 9.5% of Group A and 19% of Group B (p=0.66).

CONCLUSIONS

Intensive lipid-lowering therapy before PCI reduces minor myocardial damage during PCI with stenting compared with moderate lipid-lowering therapy.

Successful thrombus extraction with the Rescue thrombus management system during acute percutaneous coronary intervention improves flow but does not necessarily restore optimal myocardial tissue perfusion

We determined the effectiveness of the Rescue device in restoring flow and achieving optimal tissue perfusion during percutaneous coronary intervention (PCI) in thrombus-laden coronary arteries.

METHODS

A total of 30 patients with an acute coronary syndrome underwent PCI using the Rescue device.

RESULTS

The mean age was 65.5 +/- 9.8 years. Although the Rescue device could not be passed across the lesion in 6 (20%) cases, debris was aspirated in 26 (87%). The uncorrected TIMI frame count improved following the use of the Rescue device and improved further at the completion of PCI (92.2 +/- 23.9 pre-PCI vs. 38.7 +/- 31.3 post-Rescue vs. 21.96 +/- 24 post-PCI, P < 0.0001). The thrombus score improved from 4 +/- 0 to 2.2 +/- 1.29 to 0.86 +/- 1.4 (P < 0.0001). TIMI flow grade (TFG) 3 was restored in 60% of cases following the Rescue device and in 87% after PCI. Myocardial blush grade 3 occurred in only 13% of patients following the Rescue device and 37% of patients after PCI.

CONCLUSION

These data suggest that the Rescue device can aspirate considerable amounts of debris in the majority of patients and significantly improves the angiographic epicardial coronary blood flow. How effective such a device is in improving tissue perfusion and, thereby, clinical outcomes for patients remains to be seen.

Intracoronary ST-Segment Shift Soon After Elective Percutaneous Coronary Intervention Accurately Predicts Periprocedural Myocardial Injury

Background— Elevation of cardiac biomarkers after coronary angioplasty (percutaneous coronary intervention [PCI]) reflects periprocedural myocardial damage and is associated with adverse cardiac events. We assessed whether periprocedural myocardial damage that occurs despite successful PCI could be rapidly and easily identified by intracoronary ST-segment recording with the use of a catheter guidewire.

Methods and Results— In 108 consecutive stable patients undergoing elective single-vessel PCI, we recorded unipolar ECG from the intracoronary guidewire in the distal coronary before PCI and 2 minutes after the last balloon inflation. After PCI, intracoronary ST-segment shift ≥1 mm from baseline was considered significant. Troponin I levels were measured at baseline and at 8 and 24 hours after intervention, and myocardial damage was defined as troponin I increase above the upper normal value after intervention. All patients had normal cardiac marker values before PCI, and PCI was successful in all (residual stenosis <20%, Thrombolysis in Myocardial Infarction grade 3 flow). After PCI, long-term follow-up data were collected; myocardial damage was detected in 50 patients (46%), although abnormal creatine kinase-MB values were documented in only 11 (10%). Significant intracoronary ST-segment shift after PCI was present in 40 patients (37%; group A) and absent in the remaining 68 (63%; group B). Procedural myocardial damage was documented in 37 group A patients (93%) and in 13 group B patients (19%; P <0.001); significant ECG changes were found on standard ECG after intervention in only 5 patients (13%) and 1 patient (1%) ( P <0.05). Sensitivity of intracoronary ST-segment shift for predicting myocardial damage was 74%, and specificity was 95%, with positive and negative predictive values of 93% and 81%, respectively. On multivariate analysis, intracoronary ST-segment shift was the sole independent predictor of myocardial damage (odds ratio, 54.1; 95% confidence interval, 12.1 to 240; P <0.0001). At a median follow-up of 12±5 months, major coronary event–free survival was significantly worse in group A patients (log-rank test χ 2 =4.0; P <0.05).

Conclusions— After successful single-vessel PCI, intracoronary ST-segment shift allows the prompt and inexpensive identification of patients developing myocardial injury, who may require adjunctive therapy and longer in-hospital stay.

Effects of metoprolol therapy on cardiac troponin-I levels after elective percutaneous coronary interventions

AIMS

Beta-blockers (BBs) have been shown to improve survival and reduce the risk of re-infarction in patients following myocardial infarction. There are conflicting data about the effects of BB therapy on cardiac biomarkers after percutaneous coronary interventions (PCIs). The aim of the study was to investigate the effects of BB use on cardiac troponin-I (cTnI) levels in patients who had undergone elective PCI.

METHODS AND RESULTS

In this prospective study, 287 patients with coronary artery disease were included. Patients were randomized either to BB or control groups prior to the intervention. Blood samples for cTnI were obtained before and at 6, 24, and 36 h after the procedure. Of the 287 patients included, 143 received metoprolol succinate 100 mg/day, and 144 received no BB and served as the control group. Baseline clinical characteristics of both groups, except for history of coronary artery bypass graft surgery, were similar. We observed no significant difference in the elevation of cTnI levels between the two groups after PCI (BB group, 17 patients, 11.9%; control group, 10 patients, 6.9%; P=0.2).

CONCLUSION

Metoprolol succinate therapy seems to have no cardioprotective effect in limiting troponin-I rise after PCI.

Peri-procedural myocardial injury: 2005 update

During the past three decades, percutaneous coronary intervention has become one of the cardinal treatment strategies for stenotic coronary artery disease. Technical advances, including the introduction of new devices such as stents, have expanded the interventional capabilities of balloon angioplasty. At the same time, there has been a decline in the rate of major adverse cardiac events, including Q-wave acute myocardial infarction, emergency coronary artery bypass grafting, and cardiac death. Despite these advances, the incidence of post-procedural cardiac marker elevation has not substantially decreased since the first serial assessment 20 years ago. As of now, these post-procedural cardiac marker elevations are considered to represent peri-procedural myocardial injury (PMI) with worse long-term outcome potential. Recent progress has been made for the identification of two main PMI patterns, one near the intervention site (proximal type, PMI type I) and one in the distal perfusion territory of the treated coronary artery (distal type, PMI type II) as well as for preventive strategies. Integrating these new developments into the wealth of clinical information on this topic, this review aims at giving a current perspective on the entity of PMI.

Percutaneous coronary interventions for coronary artery disease: the long and short of optimizing medical therapy

Atherosclerosis is a dynamic process and timely introduction of pharmacological treatment can have a significant bearing on the patient's health and outcome. In addition to treating the culprit lesion mechanically, admission for percutaneous coronary interventions (PCI) for coronary artery disease (CAD) gives an opportunity for the interventional cardiologist to optimize medical therapy. The aim of this review is to provide an overview of the current medical literature pertaining to cardiovascular (CV) risk reduction and vascular event prevention in the setting of PCI, with emphasis on antiplatelet therapies, beta-blockers, HMG-Co A reductase inhibitors (statins) and angiotensin-converting enzyme inhibitors, with regard to therapy optimization during PCI and for chronic CAD. We discuss the effects of these oral therapies in reducing ischaemic events, thus augmenting the benefits of PCI, as well as preventing recurrent CV events after the procedure.

Randomized Trial of High Loading Dose of Clopidogrel for Reduction of Periprocedural Myocardial Infarction in Patients Undergoing Coronary Intervention

Background— Aggressive platelet inhibition is crucial to reduce myocardial injury and early cardiac events after coronary intervention. Although observational data have suggested that pretreatment with a high loading dose of clopidogrel may be more effective than a conventional dose, this hypothesis has never been tested in a randomized trial.

Methods and Results— A total of 255 patients scheduled to undergo percutaneous coronary intervention were randomized to a 600-mg (n=126) or 300-mg (n=129) loading regimen of clopidogrel given 4 to 8 hours before the procedure. Creatine kinase MB, troponin I, and myoglobin levels were measured at baseline and at 8 and 24 hours after intervention. The primary end point was the 30-day occurrence of death, myocardial infarction (MI), or target vessel revascularization. The primary end point occurred in 4% of patients in the high loading dose versus 12% of those in the conventional loading dose group ( P =0.041) and was due entirely to periprocedural MI. Peak values of all markers were significantly lower in patients treated with the 600-mg regimen ( P ≤0.038). Safety end points were similar in the 2 arms. At multivariable analysis, the high loading regimen was associated with a 50% risk reduction of MI (OR 0.48, 95% CI 0.15 to 0.97, P =0.044). An incremental benefit was observed in patients randomized to the 600-mg dose who were receiving statins, with an 80% risk reduction.

Conclusions— Pretreatment with a 600-mg loading dose of clopidogrel 4 to 8 hours before the procedure is safe and, as compared with the conventional 300-mg dose, significantly reduced periprocedural MI in patients undergoing percutaneous coronary intervention. These results may influence practice patterns with regard to antiplatelet therapy before percutaneous revascularization.

Incidence and Management of "No-Reflow" Following Percutaneous Coronary Interventions

No-reflow is a complex condition associated with inadequate myocardial perfusion of the coronary artery in the absence of epicardial obstruction. It can occur in several settings, including percutaneous coronary intervention, especially in complex thrombotic lesions of native arteries and vein grafts and in primary angioplasty. The causes of no-reflow are not completely understood, and current treatments consist of intracoronary vasodilators, antithrombotic therapies, and mechanical devices (including aspiration thrombectomy catheters and embolic protection devices).

The no-reflow phenomenon in coronary arteries

No reflow occurs when there is inadequate myocardial perfusion of a given segment of the coronary circulation without evidence of epicardial vessel obstruction. It is a rare but clinically significant condition associated with myocardial infarction and coronary interventions. Diagnosis is usually based on clinical signs of myocardial ischemia (symptoms and/or ECG changes) combined with coronary angiography. Management can be difficult and primarily consists of intracoronary administration of vasodilators. One interesting etiology is thromboembolism and this has become the focus for new potential treatments, including distal embolic protection devices.

Randomized Trial of Atorvastatin for Reduction of Myocardial Damage During Coronary Intervention

Background— Small myocardial infarctions after percutaneous coronary intervention have been associated with higher risk of cardiac events during follow-up. Observational studies have suggested that statins may lower the risk of procedural myocardial injury. The aim of our study was to confirm this hypothesis in a randomized study.

Methods and Results— One hundred fifty-three patients with chronic stable angina without previous statin treatment were enrolled in the study. Patients scheduled for elective coronary intervention were randomized to atorvastatin (40 mg/d, n=76) or placebo (n=77) 7 days before the procedure. Creatine kinase-MB, troponin I, and myoglobin levels were measured at baseline and at 8 and 24 hours after the procedure. Detection of markers of myocardial injury above the upper normal limit was significantly lower in the statin group versus the placebo group: 12% versus 35% for creatine kinase-MB ( P =0.001), 20% versus 48% for troponin I ( P =0.0004), and 22% versus 51% for myoglobin ( P =0.0005). Myocardial infarction by creatine kinase-MB determination was detected after coronary intervention in 5% of patients in the statin group and in 18% of those in the placebo group ( P =0.025). Postprocedural peak levels of creatine kinase-MB (2.9±3 versus 7.5±18 ng/mL, P =0.007), troponin I (0.09±0.2 versus 0.47±1.3 ng/mL, P =0.0008), and myoglobin (58±36 versus 81±49 ng/mL, P =0.0002) were also significantly lower in the statin than in the placebo group.

Conclusions— Pretreatment with atorvastatin 40 mg/d for 7 days significantly reduces procedural myocardial injury in elective coronary intervention. These results may influence practice patterns with regard to adjuvant pharmacological therapy before percutaneous revascularization.