Long-term clinical events following creatine kinase--myocardial band isoenzyme elevation after successful coronary stenting

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.

Positive remodeling is associated with more plaque vulnerability and higher frequency of plaque prolapse accompanied with post-procedural cardiac enzyme elevation compared with intermediate/negative remodeling in patients with acute myocardial infarction

BACKGROUND

We assessed the impact of remodeling patterns on pre- and post-procedural intravascular ultrasound (IVUS) findings and cardiac enzyme elevation after stenting in 310 acute myocardial infarction (AMI) patients.

METHODS

The positive remodeling (PR) (PR group, n=113) was defined as remodeling index (lesion/reference external elastic membrane cross-sectional area) >1.05, intermediate remodeling (IR) as between 0.95 and 1.05, and negative remodeling (NR) as<0.95 (IR/NR group, n=197). IVUS findings included ruptured plaque (a cavity that communicated with the lumen with an overlying residual fibrous cap fragment), multiple ruptured plaques (different plaque ruptures separated by a >5-mm length of artery containing smooth lumen contours), thrombus (discrete intraluminal filling defects), and plaque prolapse (tissue extrusion through the stent strut at post-stenting). We compared pre- and post-procedural IVUS findings and cardiac-specific troponin I (cTnI) elevation after stenting according to the remodeling pattern.

RESULTS

The plaque rupture (60% vs. 42%, p=0.004), multiple plaque ruptures (22% vs. 14%, p=0.014), and IVUS-detected thrombus (42% vs. 28%, p=0.012) were more common in the PR group compared with the IR/NR group. Post-stenting plaque prolapse was observed more frequently (36% vs. 22%, p=0.008), and cTnI was elevated more significantly after stenting in the PR group compared with the IR/NR group (DeltacTnI; +7.8+/-51.1 ng/ml vs. +0.9+/-41.1 ng/ml, p=0.008). Multivariate analysis showed that PR [odds ratio (OR)=1.92; 95% CI 1.04-2.98, p=0.028], plaque rupture (OR 1.98; 95% CI 1.16-3.45, p=0.025), IVUS-detected thrombus (OR 2.30; 95% CI 1.22-3.98, p=0.008), and plaque prolapse (OR 8.40; 95% CI 4.19-16.84, p<0.001) were independently associated with post-stenting cTnI elevation.

CONCLUSIONS

AMI patients with PR have more plaque vulnerability and higher frequency of plaque prolapse accompanied by post-procedural cardiac enzyme elevation compared with AMI patients with IR/NR.

Paclitaxel-eluting stent long-term outcomes in percutaneous saphenous vein graft interventions (PELOPS) study

This study examined the 1-year clinical and angiographic follow-up results of implantation of paclitaxel-eluting stents (PES) in aortocoronary saphenous vein graft (SVG) lesions. Sixty-eight consecutive patients with 90 nonoccluded SVG lesions were treated with PES (Taxus), size ranging from 2.25 to 4.5 mm. Angiographic follow-up was performed on 63 patients (93%) and 83 lesions (92%) at 12 months; major adverse cardiac event (MACE) was recorded in all patients at 1 year. The mean age of patients was 71+/-8 years with predominance of men (75%); the mean graft age was 13+/-4 years. Glycoprotein IIb/ IIIa inhibitors were given in 21 patients (31%); embolic protection devices were used in 54 lesions (60%). On average, patients received 1.4 stents per lesion with a stent size of 3.4+/-0.6 mm and a length of 35.8+/-27.0 mm. Angiographic follow-up revealed a late loss of 0.36+/-0.66 mm with an in-segment binary restenosis rate of 7%. The in-hospital MACE was 7%, which was solely contributed by 5 patients with postprocedure non-Q myocardial infarction; the 1-year MACE was 15%, accounted by 1 noncardiac death and 9 patients with target vessel revascularization. Peripheral vascular disease and the use of glycoprotein IIb/ IIIa inhibitors were the independent predictors of MACE at 1 year. In conclusion, implantation of PES to treat degenerative aortocoronary SVG lesions is safe and associated with low late loss, angiographic restenosis, and MACE at 1-year follow-up.

Significance of Periprocedural Myonecrosis on Outcomes After Percutaneous Coronary Intervention

Background— Myonecrosis after percutaneous coronary intervention (PCI) has been correlated with a worse prognosis, but controversy exists about the clinical significance and potential mechanisms for the association. The aim of this study was to evaluate the relative impact of preprocedural and postprocedural cardiac troponin T (cTnT) levels on survival rate after PCI.

Methods and Results— We evaluated 5487 patients from the Mayo Clinic registry who required nonemergency PCI, and we examined the relationship between periprocedural cTnT levels, with the 99th percentile cutoff value used for normal (<0.01 ng/mL), and outcomes. The patients were divided into 3 groups: normal preprocedural and postprocedural cTnT levels (no myonecrosis), normal preprocedural but elevated postprocedural cTnT levels (PCI-related myonecrosis), and abnormal preprocedural cTnT. The 30-day death rates were 0.1%, 0.6%, and 2.3%, respectively, in the 3 groups. In a multivariable model, an abnormal pre-PCI cTnT level (hazard ratio 9.66 [2.30–40.57]; P =0.002), and PCI-related myonecrosis (4.71 [1.02–21.83]; P =0.048) were independent predictors of 30-day mortality. Over a median follow-up of 28 months, an abnormal pre-PCI cTnT level (hazard ratio 1.79 [1.35–2.39]; P <0.001) independently predicted death, but the occurrence of PCI-related myonecrosis did not. A postprocedural elevation in creatine kinase MB fraction was not an independent predictor of long-term risk of death (0.912 [0.70–1.19]; P =0.5).

Conclusions— A preprocedural cTnT level >0.01 is a powerful independent predictor of prognosis after PCI and is of greater prognostic significance than the postprocedural biomarker levels. PCI-related myonecrosis occurs frequently and predicts short-term but not long-term risk of death.

Evolution of anticoagulant and antiplatelet therapy: benefits and risks of contemporary pharmacologic agents and their implications for myonecrosis and bleeding in percutaneous coronary intervention

Periprocedural myonecrosis, as evidenced by elevated creatine kinase-myocardial bound (CK-MB) levels, occurs in up to 25% of patients undergoing percutaneous coronary intervention (PCI) and has been linked with an increased risk of adverse short- and long-term clinical outcomes. Such myonecrosis arises from three main pathophysiological mechanisms: procedure-related complications, lesion-specific characteristics (e.g., large thrombus burden, plaque volume), and patient-specific characteristics (e.g., genetic predisposition, arterial inflammation). Periprocedural myonecrosis has not been definitively identified as the cause of postprocedural ischemic events, although agents that reduce or prevent thrombosis--including aspirin, thienopyridines, heparin, low-molecular-weight heparins, glycoprotein IIb/IIIa inhibitors, and direct thrombin inhibitors--have been shown to reduce the incidence of ischemic outcomes in this population, as have agents that reduce inflammation (aspirin, statins). At the same time, antithrombotic agents are known to increase the risk of bleeding and the use of transfusions, which have likewise been associated with worse outcomes in these patients. Thus, optimal management of patients undergoing PCI represents a balance between minimizing the risk of ischemic outcomes and simultaneously minimizing the risk of major bleeding. It may be that patients who have only minor, untreated postprocedural elevations in CK-MB level (with no clinical or angiographic signs of ischemia) might have a better prognosis than patients who have normal CK-MB levels but who suffer major bleeding complications.

Usefulness of statin pretreatment to prevent contrast-induced nephropathy and to improve long-term outcome in patients undergoing percutaneous coronary intervention

Contrast-induced nephropathy (CIN) is an important cause of mortality and morbidity in patients undergoing angiography. This study investigated whether statins decrease incidence of CIN in the setting of percutaneous coronary intervention (PCI) and evaluated the influence of such potential benefit on long-term outcome. Four-hundred thirty-four patients undergoing PCI were prospectively enrolled and followed up to 4 years. Patients were stratified according to preprocedural statin therapy (260 statin treated, 174 statin naive). CIN was defined as a postprocedural increase in serum creatinine of >or=0.5 mg/dl or>25% from baseline. Follow-up assessment included 4-year occurrence of major adverse cardiac events. Statin-treated patients had a significantly lower incidence of CIN (3% vs 27%, p<0.0001; 90% risk decrease) and had better postprocedural creatinine clearance (80+/-20 vs 65+/-16 ml/min, p<0.0001). Benefit of statin before treatment was observed in all subgroups, except in patients with a pre-existing creatinine clearance<40 ml/min. During follow-up, CIN was a predictor of poorer outcome; 4-year survival free of major adverse cardiac events was highest in statin-treated patients without CIN (95%, p<or=0.015) and lowest in statin-naive patients with CIN (53%, p<or=0.018). In conclusion, patients receiving statins before PCI have a significant decrease of CIN; this early protective effect translates into better long-term event-free survival. These results may lend further support to utilization of statins as adjuvant pharmacologic therapy before PCI.

Impact of periprocedural myonecrosis on clinical events after implantation of drug-eluting stents

BACKGROUND

High level of creatine kinase myocardial band isoenzyme (CK-MB) elevation has been associated with late mortality after coronary intervention. We sought to evaluate the impact of periprocedural myonecrosis on clinical events in patients undergoing drug-eluting stents (DES) implantation.

METHODS

A total of 1807 patients (2550 lesions) with successful DES implantation were followed for mean duration of 13 + or - 7 months. Patients with acute myocardial infarction and those with elevated CK-MB at baseline were excluded. Based on the CK-MB levels after stenting, patients were classified into three groups: group I: normal CK-MB (n=1429, 79.1%), group II: 1 to 5 times normal CK-MB (n=263, 14.6%), and group III: >5 times normal CK-MB (n=115, 6.4%). Major adverse cardiac events (MACE) were defined as cardiac death, myocardial infarction, and target lesion revascularization.

RESULTS

With increasing levels of periprocedural CK-MB, there was an increased incidence of MACE (5.0% in group I vs. 6.1% in group II vs. 10.4% in group III, p=0.010) and cardiac death (0.5% in group I vs. 1.1% in group II vs. 2.6% in group III, p=0.016). By multivariate analysis, periprocedural peak CK-MB level was independent predictor of MACE (hazard ratio 1.01, 95% confidence interval 1.00 to 1.03; p=0.044).

CONCLUSIONS

Periprocedural myonecrosis was significantly associated with subsequent adverse clinical events after DES implantation.

Predictors of periprocedural creatine kinase-myocardial band elevation complicating elective percutaneous coronary intervention

Limited data are available regarding the predictors of periprocedural creatine kinase-MB (CK-MB) isoenzyme increase after elective percutaneous coronary intervention (PCI) in the stenting era. We explored the predictors of periprocedural CK-MB increase in 882 consecutive patients with normal preprocedural CK-MB who underwent 919 angiographically successful elective PCIs with (n = 814) or without (n = 105) stenting. Patients were categorized into 3 groups based on their peak CK-MB levels after PCI: (1) normal CK-MB (n = 761), (2) minor CK-MB increase (CK-MB 1 to 3 times normal, n = 112), and (3) major CK-MB increase (CK-MB >3 times normal, n = 46). By logistic regression analysis, independent predictors for minor CK-MB increase included thrombus (odds ratio [OR] 5.09, p = 0.001), platelet IIb/IIIa antagonist use (OR 0.53, p <0.01), number of lesions treated (per additional lesion, OR 1.54, p <0.01), maximum balloon size (per millimeter increase, OR 1.57, p <0.05), American College of Cardiology/American Heart Association type C lesion (OR 1.68, p <0.05), sustained chest pain during procedure (OR 1.94, p <0.05), dissection (OR 2.05, p <0.05), and transient side branch occlusion (OR 4.54, p <0.05). Independent predictors for major CK-MB increase were chest pain at end of procedure (OR 9.66, p <0.001), type C lesion (OR 2.42, p <0.05), Canadian Cardiovascular Society angina class III to IV (OR 3.32, p <0.05), thrombus (OR 5.09, p = 0.001), and abrupt closure (OR 5.30, p <0.05). In conclusion, baseline clinical and angiographic characteristics and procedural complications were associated with minor and major CK-MB increases. Patients with chest pain at the end of the procedure were at the highest risk for major CK-MB increase.

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.

Stenting of coronary bifurcation lesions by using modified crush technique with double kissing balloon inflation (sleeve technique): Immediate procedure result and short-term clinical outcomes

BACKGROUND

Sleeve technique is a modified version of crush technique. It is specifically designed to increase the success rate of final kissing balloon inflation, which used to be a major limitation of the latter.

OBJECTIVES

The aim of this study was to examine the feasibility, safety, and early clinical outcomes of sleeve technique in stenting different types (de novo, in-stent restenotic or in-stent bifurcation) of coronary bifurcation lesions at different locations.

METHODS

From August 2005 to May 2006, 41 consecutive patients with symptomatic, nonleft-main coronary bifurcation stenoses of diameter narrowing >or=50% were treated with two-stent strategy, using sleeve technique.

RESULTS

The mean age was 63.6 +/- 11.6 years with male predominance (70.7%). High prevalence of diabetes mellitus (31.7%), total occlusion (22.0%), and multi-vessel disease (65.9%) was observed in this cohort. Intravenous abciximab was given in 35 (85.4%) patients. Final kissing balloon inflation was successfully performed in all patients. The minimal luminal diameter in main vessel and side branch was increased from 0.97 +/- 0.53 mm and 0.81 +/- 0.45 mm to 2.76 +/- 0.34 mm and 2.22 +/- 0.35 mm, respectively. The mean procedure time was only 66.6 +/- 24.6 min. There was one (2.4%) case of subacute stent thrombosis presented as non-Q-wave myocardial infarction at day 3 postprocedure. The resultant in-hospital and 30-day major adverse cardiac event rate were both 2.4%.

CONCLUSIONS

Sleeve technique is a feasible and efficient approach in stenting of coronary bifurcation stenoses.

Cardiac troponin I release after coronary artery bypass grafting operation: effects on operative and midterm survival

BACKGROUND

Markers of myocardial necrosis are usually elevated in patients who have undergone a coronary bypass operation with cardiac arrest. The preferred marker in detecting acute myocardial ischemia is cardiac troponin I (cTnI). However, its ability to predict short-term and, particularly, midterm outcome after coronary bypass operations is uncertain.

METHODS

Two hundred thirty unselected patients undergoing surgical revascularization had cTnI measured preoperatively and 11 times postoperatively. Receiver operating characteristic curves were constructed using cTnI postoperative peak values in order to assess the prognostic sensitivity and specificity of the test. The cut-off value of 13 ng/mL was used to assess the prognostic significance of the peak cTnI postoperative release for short-term and midterm outcomes.

RESULTS

One hundred forty-six patients (63.5%) had postoperative cTnI peak values less than 13 ng/mL (mean peak value, 6.6 +/- 3.1 ng/mL) and 84 patients (36.5%) had postoperative cTnI peak values greater than 13 ng/mL (mean peak value, 45.5 +/- 59.9 ng/mL). Patients with peak cTnI greater than 13 ng/mL were older and had higher preoperative cTnI values. They required both longer cross-clamp time and CPB time. Moreover, hospital death in the cTnI greater than 13 ng/mL group (9.5% versus 0.7%, p = 0.0009) was significantly higher. Multivariate analysis showed that cTnI greater than 13 ng/mL was the only independent predictor of hospital death (odds ratio 10.33, p = 0.04) and hospital death from cardiac causes. A 2-year follow-up demonstrates that cTnI postoperative release had no influence on midterm mortality and hospitalization for due to cardiac illness.

CONCLUSIONS

Cardiac troponin I is a valuable marker for immediate myocardial damage after coronary bypass operations. Its postoperative release does not predict midterm outcome.

Isolated Elevation in Troponin T After Percutaneous Coronary Intervention Is Associated With Higher Long-Term Mortality

OBJECTIVES

The aim of this study was to evaluate whether, in patients with normal post-procedure CK-MB, an isolated elevation in cardiac troponin T (cTnT) predicts long-term survival.

BACKGROUND

Cardiac troponin T is a sensitive and specific marker of myonecrosis. There is little known about the incidence and prognostic significance of an isolated elevation of cTnT without a rise in creatine kinase (CK)-MB following PCI.

METHODS

We evaluated the outcomes of 1,949 patients from the Mayo Clinic registry who had normal pre-procedure cTnT and CK-MB, required nonemergency percutaneous coronary intervention (PCI), and had normal CK-MB after the procedure.

RESULTS

An elevation in cTnT (cTnT+) was observed in 383 patients (19.6%) (median 0.04 ng/ml, interquartile range 0.03 to 0.06 ng/ml). The TnT+ status was associated with adverse clinical and angiographic characteristics, and multivessel PCI. Over the median follow-up duration of 26 months, mortality (p < 0.001) and the combined rate of death and myocardial infarction (p = 0.004) were significantly higher in cTnT+ patients. Estimated 3-year survival for those with and without cTnT elevation was 86.9% and 93.2%, respectively. By multivariate analysis, an elevation in cTnT after PCI was an independent predictor of increased long-term mortality. A doubling in the post-PCI cTnT was associated with a partial hazard ratio of 1.20 (95% confidence interval 1.02 to 1.40; p = 0.023).

CONCLUSIONS

An isolated minor elevation in cTnT after PCI provides long-term prognostic information regarding mortality and myocardial infarction.

Angiographic adverse events during percutaneous coronary intervention fail to predict creatine kinase-MB elevation

We attempted to determine if aggressive detection of angiographic adverse events during coronary intervention could predict subsequent creatine kinase (CK)-MB elevations. During coronary intervention, both fluoroscopy and cine angiography were used to detect angiographic adverse events. At least one angiographic adverse event occurred in 133/251 (53%) of procedures. CK-MB elevation occurred in 24% of procedures. Slow flow during the procedure (P=0.002) and chest discomfort at the end of the procedure (P=0.007) were the strongest predictors of CK-MB elevation. Among procedures with no angiographic adverse events, CK-MB elevation occurred in 15/121 (12%), accounting for 25% of CK-MB elevations. We conclude that CK-MB elevation occurs after angiographically uncomplicated coronary interventions even when angiographic adverse events are aggressively detected. Routine monitoring of cardiac enzymes is necessary to detect all patients who will experience myocardial injury after coronary intervention.

Angiographic adverse events, creatine kinase-MB elevation, and ischemic end points complicating percutaneous coronary intervention (a REPLACE-2 substudy)

Several angiographic adverse events during coronary balloon angioplasty have been associated with increased creatine kinase-MB (CK-MB) enzymes and adverse clinical outcomes. The significance of angiographic adverse events in the stent era has not been widely studied. We analyzed 10 types of angiographic adverse events that were reported in the 6,010-patient Second Randomized Evaluation in PCI Linking Angiomax to Reduced Clinical Events (REPLACE-2) trial to determine their relation to CK-MB elevation and clinical ischemic end points after percutaneous coronary intervention (PCI). Angiographic adverse events occurred in 9.1% of REPLACE-2 patients. Most (8 of 10) types of angiographic adverse events were associated with an increased risk of increased CK-MB (p <0.001 for each), and 47% of all patients with an angiographic adverse event developed increased CK-MB. Logistic regression analysis showed that the strongest predictor of death, myocardial infarction, or revascularization at 6 months was the occurrence of an angiographic adverse event during PCI (odds ratio 1.9, 95% confidence interval 1.6 to 2.4, p <0.001). Side branch closure, abrupt closure, any decreased flow during the procedure, angiographic distal embolization, and perforation or tamponade were individual predictors of the occurrence of the combined clinical ischemic end point at 6-month follow-up (p <0.005 for each). In conclusion, most angiographic adverse events during PCI are associated with increased CK-MB and are powerful predictors of adverse clinical events within 6 months.

Preprocedural statin therapy reduces the risk and extent of cardiac biomarker release following percutaneous coronary intervention

This study evaluates the association between statin therapy in patients treated by percutaneous coronary intervention (PCI) for stable angina pectoris and postinterventional myocardial injury with subsequent long-term clinical outcome. Prospectively collected data on 400 consecutive patients with stable angina pectoris or evidence of inducible myocardial ischemia were analyzed. The incidence of myocardial infarction based on postinterventional release of troponin I>1.5 ng/ml was 12% in the statin pretreated patients and 20% in those not pretreated with statin therapy (P=0.04, odds ratio 1.84, 95% confidence interval 1.06-3.21). Of the patients experiencing a post-PCI troponin elevation>1.5 ng/ml, those pretreated with a statin pre-PCI had a lesser troponin elevation compared with those not receiving a statin pre-PCI (median: 2.9 ng/ml [1.9-11.5] vs 5.0 ng/ml [3.1-8.8]; P<0.001). In the multivariate model, preprocedural statin therapy was identified as the only independent negative predictor of procedure-related myocardial necrosis based on postprocedural troponin elevation. In the 21-month follow-up period, statin pretreated patients were observed to have fewer deaths, revascularizations, or myocardial infarction; however, this difference was not statistically significant. These results suggest that pretreatment with statins in patients undergoing PCI for stable angina pectoris reduces the risk and extent of procedure-related myocardial injury measured by troponin release.

Long-term outcome of patients with perioperative myocardial infarction as diagnosed by troponin I after routine surgical coronary artery revascularization

OBJECTIVE

Diagnosis of perioperative myocardial infarction (P-MI) after coronary artery bypass graft (CABG) surgery traditionally relied on a combination of electrocardiographic and enzyme assay changes. Patients with Q-wave P-MIs who survive to hospital discharge have a poorer long-term prognosis. Troponin assays are more sensitive and specific for detecting minor P-MI, with an increased incidence of P-MI being reported. This study investigated if P-MI after CABG surgery, as defined by troponin-I isozyme (cTn-I), correlated with long-term outcome.

DESIGN

A prospective, observational study.

SETTING

A single-institution, cardiothoracic specialty hospital.

PARTICIPANTS

Seventy patients undergoing elective CABG surgery.

INTERVENTIONS

Patients (n = 70) were stratified into low-risk and high-risk groups according to the absence (cTn-I <15 microg/L) or presence (cTn-I >or=15 microg/L) of P-MI after CABG surgery. Patients with (n = 24) and without (n = 46) P-MI were then followed for 3 years after CABG surgery to determine the impact of cTn-I-defined P-MI on long-term outcome.

MEASUREMENTS AND MAIN RESULTS

Most patients felt that their quality of life and activity index had improved and that their symptoms of angina had lessened at 12-month follow-up. However, cardiovascular event-free survival was significantly less in patients with P-MI (p = 0.01) 3 years postoperatively. The incidence for cardiovascular events was 0.24 versus 0.65 (p = 0.049) in those patients without and with P-MI, respectively. The hazard ratio (2.9; 95% confidence interval, 1.3-9.4) for cardiovascular incidents was also significantly greater in patients with P-MI. More specifically, the incidence of arrhythmia was 2.4% versus 26.1% (p < 0.01), and the incidence of vascular events was 4.9% versus 26.1% (p = 0.02) in patients without and with P-MI, respectively.

CONCLUSIONS

It was shown that P-MI as defined by cTn-I is associated with an increased long-term incidence of adverse cardiovascular events. An elevated peak cTn-I level (>or=15 microg/L) identified patients at increased risk but did not have a powerful positive predictive value for either cardiovascular (48%) or vascular (26%) complications. However, a peak cTn-I <15 microg/L was a negative predictor of adverse vascular outcome (95%). This may have implications for postoperative patient follow-up.

Filter no reflow during percutaneous coronary interventions using the Filterwire distal protection device

BACKGROUND

Distal protection devices are increasingly used to prevent embolization during percutaneous coronary interventions (PCI) in saphenous vein grafts (SVG) and native coronary arteries (NV). During interventions with the Filterwire device we have observed reduced flow that is reversible following removal of the filter (filter no reflow, FNR), which might be erroneously interpreted as true no reflow and might be associated with reduced capture efficiency of the basket.

METHODS

We analyzed the incidence of FNR in 58 patients (60 lesions) at high risk of embolization undergoing PCI of either a SVG or a NV using the Filterwire (Boston Scientific, Natick, MA). Qualitative and quantitative angiographic analysis was performed, and the volume of collected debris was estimated using a photographic technique.

RESULTS

In our population, about 1/3 of the cases showed FNR, which was associated with angiographically visible filling defects within the basket, indicating macroembolism. However some patients (especially those undergoing vein graft interventions) showed filling defects without FNR, and some others FNR without filling defects. Thus we tried to understand the predictors of FNR: FNR was associated with higher amount of collected debris (36.97 +/- 42.98 mm(3) vs. 11.31 +/- 18.47 mm(3), p = 0.005), was neither prevented by abciximab, nor predicted by high thrombotic burden, increasing stent volume or need for predilatation. When patient with and without angiographically evident macroembolisation were separately analyzed, a linear correlation of FNR with the quantity of debris was only apparent in the macroembolization group.

CONCLUSIONS

Interventionalists should be aware of the "Filter No Reflow", a common but reversible angiographic complication when the Filterwire device is used. Reduced flow seen during these procedures should be treated conservatively. Mechanical obstruction of the filter, but also other mechanisms (pharmacologically active debris? platelet aggregates?) play a role in this phenomenon.

MC-1 (pyridoxal 5'-phosphate): novel therapeutic applications to reduce ischaemic injury

Despite the overall efficacy of mechanical reperfusion therapies, such as percutaneous coronary intervention and coronary artery bypass graft surgery, in reducing the morbidity and mortality that is associated with acute ischaemic syndromes, many of the treated patients develop ischaemia-reperfusion injury due to impaired microvascular integrity, embolisation of atherothrombotic debris and/or disrupted end-organ metabolism. MC-1 is an investigational drug from Medicure, Inc. In preclinical models of ischaemia and ischaemia-reperfusion injury, treatment with MC-1 has demonstrated significant cardio- and neuroprotective effects. Although the pharmacological activity of MC-1 may involve multiple mechanisms, research suggests that at least part of the protective effect may be mediated through its actions on purinergic receptors. Early clinical experience with MC-1 also appears to be promising: in a recent Phase II evaluation, treatment with MC-1 was associated with a statistically significant reduction in periprocedural infarct size (as measured by area under the curve creatine kinase-myocardial band) among high-risk patients undergoing elective percutaneous coronary intervention. Based on these findings, larger, randomised trials to confirm the safety and efficacy of MC-1 in the setting of coronary artery revascularisation with coronary artery bypass graft, acute coronary syndromes and stroke are ongoing or in development. These forthcoming evaluations should clarify the safety and efficacy of MC-1 and improve the understanding regarding its potential therapeutic role in a variety of clinical settings and indications.

Nicorandil reduces the incidence of minor cardiac marker elevation after coronary stenting

BACKGROUND

Minor cardiac marker elevation after percutaneous coronary intervention has long-term prognostic significance. We examined whether nicorandil, a nicotinamide-nitrate ester, reduces the incidence of minor cardiac marker elevation after coronary stenting.

METHODS

Patients (n=192) undergoing coronary stenting were randomly assigned to receive nicorandil (nicorandil group, n=91) or vehicle (control group, n=101). Nicorandil (2 mug/kg/min, intravenously) was administered immediately after the patients were transferred into the catheterization laboratory and continued for 6 h. We measured the serum concentrations of creatine kinase isoenzyme MB (CK-MB) before, immediately after, and 6, 12, and 24 h after the procedure, and those of cardiac troponin T (cTnT) 24 h after the procedure.

RESULTS

There was no significant difference in clinical background between the 2 groups. The nicorandil group showed a significantly lower incidence of CK-MB elevation (>1x upper limit of control range, 20 IU/l) than the control group (8.8% vs 21.8%, p<0.05). The levels of serum CK-MB in the nicorandil group were significantly lower than those in the control group (13.4+/-5.7 vs 16.5+/-9.7 IU/l, p<0.01). Similarly, the nicorandil group showed a significantly lower incidence of cTnT elevation [>1x (0.1 ng/ml) or >2x (0.2 ng/ml)] upper limit of control range than the control group (14.3% vs 26.7%, p<0.05, or 7.7% vs 17.8%, p<0.05). Serum cTnT levels were also significantly lower in the nicorandil group than in the control group (0.05+/-0.10 vs 0.15+/-0.36 ng/ml, p<0.05).

CONCLUSIONS

The results demonstrated that nicorandil reduces minor cardiac marker elevation after coronary stenting.

The new definition of myocardial infarction and the impact of troponin determination on clinical practice

OBJECTIVE

To discuss the more controversial clinical and laboratory aspects in the application of the new biochemical diagnostic standard for myocardial infarction, 4 years after its introduction, and to make some suggestions, which could allow for a more realistic application of the new definition in the current clinical practice.

METHODS

Studies published in the last 4 years in the most important cardiology and laboratory medicine journals (including proceedings of the international meetings), discussing advantages and limits of the new definition of myocardial infarction, were reviewed and pertinent data were discussed and compared with similar information available in literature.

RESULTS AND CONCLUSIONS

Although the exact status of implementation of the new definition of myocardial infarction cannot yet be known, the trend toward such recommendation is evolving significantly, even if at different rates in different countries. To make the transition smoother, major educational efforts are required to disseminate the conceptual reasoning behind the new guidelines. On the other hand, more knowledge is needed for some relevant issues, such as the different analytical performance of cardiac troponin assays or the prognostic significance of biomarker changes after a percutaneous coronary intervention.

Comparison of the effectiveness of sirolimus- and paclitaxel-eluting stents for small coronary artery lesions

BACKGROUND

The sirolimus-eluting stent (SES) and the paclitaxel-eluting stent (PES) reduce restenosis in small coronary artery lesions. However, it is not clear which of these stents is superior in terms of clinical outcomes.

METHODS

The authors retrospectively examined 197 patients with 245 de novo small coronary artery lesions (<or=<or=2.75 mm) that were treated with either the SES (156 lesions) or the PES (89 lesions). Six-month angiographic restenosis rates and the 9-month target lesion revascularization (TLR) rates were compared between the two groups.

RESULTS

In terms of baseline clinical and angiographic parameters, the two groups well matched together. Six-month angiographic follow-up was performed on 170 patients (86.3%), comprising 135 SES lesions (86.5%) and 76 PES lesions (85.4%). At 6-month angiographic follow-up, the late lumen loss was less in the SES group than in the PES group (0.29 +/- 0.42 vs. 0.69 +/- 0.63 mm, P < 0.01). Therefore, the SES group showed a lower rate of angiographic restenosis than the PES group (6.7% vs. 27.7%, P < 0.01). At 9 months there were no deaths or myocardial infarctions in either group. The 9-month TLR rate was lower in the SES group than in the PES group (3.3% vs. 14.4%, P < 0.01). The Kaplan-Meier estimate of freedom from TLR at 9 months was 96.7% for the SES patients and 86.5% for the PES patients (P < 0.01).

CONCLUSIONS

The SES treatment may be superior to the PES treatment in terms of long-term clinical and angiographic outcomes in patients with small coronary artery lesions.

"Full metal jacket" (stented length > or =64 mm) using drug-eluting stents for de novo coronary artery lesions

BACKGROUND

Stented segment length was a predictive factor for restenosis in the bare metal stent era. The objective of the study was to evaluate the medium-term clinical outcome and the potential for adverse effects when very long segments (ie, > or =64 mm of stented length) are treated by drug-eluting stent (DES) implantation, an approach colloquially referred to as a "full metal jacket."

METHODS

Since April 2002, we have used DES as the default stent for all percutaneous coronary interventions. From our prospective institutional database we identified 122 consecutive patients, with de novo coronary lesions, in whom a coronary artery was treated with at least 64 mm of overlapping DES: 81 patients were treated with sirolimus-eluting stents and 41 with paclitaxel-eluting stents.

RESULTS

The mean number of stents per lesion was 3.3 +/- 1.1, and the median stented length was 79 mm (range 64-168 mm). Periprocedural Q-wave myocardial infarction (MI) occurred in 2 patients (1.6%) and subacute stent thrombosis in 1 patient (0.8%). During 1-year follow-up, 5 patients (4.1%), including 3 patients treated for acute MI with cardiogenic shock, died and 10 patients (8.2%) had nonfatal MI (creatine kinase-MB >3 times). The 1-year target vessel revascularization rate was 7.5% and the overall incidence of major adverse cardiac events was 18%. Outcomes in sirolimus-eluting stents and paclitaxel-eluting stents groups did not differ statistically.

CONCLUSIONS

The use of DES for the treatment of diffuse lesions was associated with a low rate of repeat revascularization, irrespective of stent type. No safety concerns were raised at medium-term follow-up.

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.

Safety of coronary angioplasty to chronic total occlusions

Percutaneous transluminal coronary angioplasty (PTCA) of chronic total occlusions (CTO) is not performed routinely in some centres due to concerns of low procedural success rates and high rates of short-term complications. This retrospective study examines the safety of PTCA to CTO in 100 consecutive cases compared to 100 matched controls. Success rate was 79% for CTO versus 98% for controls (p<0.001), however 5% of CTO patients had a cardiac enzyme rise compared to 13% of controls (p<0.05) and 0% of CTO patients compared to 6% of controls had a significant enzyme rise (p=0.03). These results suggest that PTCA to CTO can be carried out successfully in the majority of patients with only a relatively small risk of myocardial necrosis.

Impact of platelet glycoprotein IIb/IIIa Inhibition on the paclitaxel-eluting stent in patients with stable or unstable angina pectoris or provocable myocardial ischemia (a TAXUS IV substudy)

Whether the benefits that glycoprotein IIb/IIIa inhibitors confer in patients who undergo bare metal stent implantation extend to drug-eluting stents is unknown. We performed a prespecified subgroup analysis of the TAXUS IV study population to examine the effect of procedural glycoprotein IIb/IIIa inhibition during paclitaxel-eluting stent implantation on periprocedural creatine kinase-MB (CK-MB) levels. Glycoprotein (GP) IIb/IIIa inhibitors were administered to 57.7% of patients who had been randomized to receive the TAXUS stent and to 56.7% of those who had been randomized to receive the control stent. Among patients who received the TAXUS stent, the rate of CK-MB increases of >3 times the normal level was 2.6-fold higher in those who received a GP IIb/IIIa inhibitor than in those who did not (11.4% vs 4.4%, p = 0.0015). Composite rates of major adverse cardiac events and target vessel failure were also higher at 1 month in the GP IIb/IIIa group. By multivariate analysis, use of GP IIb/IIIa inhibitors during stenting with the TAXUS stent was an independent predictor of CK-MB increases >3 times the normal level. Further studies are warranted.

Occurrence of Non-Q wave Myocardial Infarction Following Percutaneous Coronary Intervention in the Stent Era: Systematic Monitoring of the Three Markers of Myocardial Necrosis

OBJECTIVES

To compare the elevation of the three markers total creatine kinase (CK), CK-MB mass, and troponin I (TnI) and their relationship with clinical and procedural characteristics following percutaneous coronary intervention (PCI).

METHODS

We prospectively evaluated 385 patients consecutively undergoing successful PCI. The three markers were systematically measured before and at 6, 12, and 24 hours after PCI. Any increase above the upper normal limit (UNL) of any marker has been considered abnormal when basal values were normal, while a further increase was needed when basal values were altered. Patients with ongoing acute myocardial infarction were excluded from the analysis.

RESULTS

TnI was above UNL in 183 patients (51%); in 138 (38.5%) it was the only marker altered. CK-MB mass was elevated in 12.8% patients, more than 3x UNL in 5.5% and more than 5x UNL in 2.8%. In over one half of these patients, CK-MB values peaked at 12 hours following PCI. Total CK was above UNL in 23 patients only (6.4%) and more than twice UNL in 5 (1.4%). Only 1 patient out of the 5 with CK-MB mass more than 10x UNL had total CK higher than twice UNL. In our population, post-PCI elevation of myocardial necrosis markers correlate with the occurrence of minor procedural complications (observed overall in 7.8% cases; TnI and/or CK-MB > 1xUNL 96% vs 47.5%, P < 0.001) and the presence of higher complexity clinical and/or procedural features, such as multivessel disease, multivessel or multilesion PCI, multiple stenting and use of glycoprotein IIb/IIIa inhibitors.

CONCLUSIONS

The elevation of at least one biochemical marker of myocardial necrosis is frequent following successful PCI with routine stent implantation. CK-MB mass is the most practical marker, having optimal kinetic and peaking with the first 12-18 hours post-PCI. Definitive data on the prognostic role and the applicability for the diagnosis of myocardial infarction of minor elevation of CK-MB mass or isolated increase of TnI are lacking.

Clopidogrel Loading With Eptifibatide to Arrest the Reactivity of Platelets

Background— Pretreatment is not the most common strategy practiced for clopidogrel administration in elective coronary stenting. Moreover, limited information is available on the antiplatelet pharmacodynamics of a 300-mg versus a 600-mg clopidogrel loading dose, and the comparative effect of eptifibatide with these regimens is unknown.

Methods and Results— Patients undergoing elective stenting (n=120) were enrolled in a 2×2 factorial study (300 mg clopidogrel with or without eptifibatide; 600 mg clopidogrel with or without eptifibatide) (Clopidogrel Loading With Eptifibatide to Arrest the Reactivity of Platelets [CLEAR PLATELETS] Study). Clopidogrel was administered immediately after stenting. Aggregometry and flow cytometry were used to assess platelet reactivity. Eptifibatide added a ≥2-fold increase in platelet inhibition to 600 mg clopidogrel alone at 3, 8, and 18 to 24 hours after stenting as measured by 5 μmol/L ADP–induced aggregation ( P <0.001). Without eptifibatide, 600 mg clopidogrel produced better inhibition than 300 mg clopidogrel at all time points ( P <0.001). Glycoprotein IIb/IIIa (GPIIb/IIIa) blockade was associated with lower cardiac marker release. Active GPIIb/IIIa expression was inhibited most in the groups treated with eptifibatide ( P <0.05).

Conclusions— In elective stenting without clopidogrel pretreatment, use of a GPIIb/IIIa inhibitor produces superior platelet inhibition and lower myocardial necrosis compared with high-dose (600 mg) or standard-dose (300 mg) clopidogrel loading alone. In the absence of a GPIIb/IIIa inhibitor, 600 mg clopidogrel provides better platelet inhibition than the standard 300-mg dose. These results require confirmation in a large-scale clinical trial.

Preprocedural plasma C-reactive protein levels, postprocedural creatine kinase-MB release, and long-term prognosis after successful coronary stenting (four-year results from the GENERATION study)

Increased creatine kinase-MB isoenzymes after coronary stenting are common, and many studies have suggested an association of this increase with an adverse long-term prognosis. How such postprocedural creatine kinase-MB release affects long-term prognosis remains unclear. Whether any actual causal relation exists remains unanswered.

Differential mortality risk of postprocedural creatine kinase-MB elevation following successful versus unsuccessful stent procedures

OBJECTIVES

This study was designed to evaluate the effect of periprocedural myocardial infarction (MI) on mortality according to success of the stent procedure.

BACKGROUND

The mortality effect of periprocedural MI relative to successful versus unsuccessful procedures has not been examined.

METHODS

All-cause mortality during the first year was evaluated prospectively among 5,850 patients from coronary stent clinical trials. Myocardial infarction was classified according to creatine kinase-MB level as type 1 (>1 but <3 times normal), type 2 (>or=3 but <or=8 times normal), or type 3 (>8 times normal or Q-wave MI). Procedures were classified as successful unless there was a final diameter stenosis >50%; final Thrombolysis In Myocardial Infarction flow grade <3; final National Heart, Lung, and Blood Institute dissection grade >or=D; repeat revascularization within 24 h; or stent thrombosis within 24 h.

RESULTS

Myocardial infarction was more frequent after unsuccessful procedures (69.6% vs. 20.4%, p < 0.001). Mortality during the first year was higher in patients with MI (2.8% vs. 1.7%, p = 0.01), but the effect was significant only for type 3 MI (4.7% vs. 1.7%, p = 0.008). Moreover, the mortality difference for any MI was confined to patients with unsuccessful procedures (13.1% vs. 0%, p = 0.03), with no significant effect among patients with otherwise successful procedures (2.1% vs. 1.7%, p > 0.20). The independent predictors of mortality were unsuccessful procedure (p < 0.001), diabetes mellitus (p = 0.001), history of prior MI (p = 0.003), multivessel disease (p = 0.006), and advancing age (p < 0.001), but not periprocedural MI.

CONCLUSIONS

The association of periprocedural MI with increased mortality during the first year following stent placement was confined to patients with unsuccessful procedures.

Causes of acute renal dysfunction after percutaneous coronary intervention and comparison of late mortality rates with postprocedure rise of creatine kinase-MB versus rise of serum creatinine

Increases in both serum creatinine and creatine kinase-MB (CK-MB) after percutaneous coronary intervention are associated with increased risk for late adverse cardiovascular events. In 5,397 patients, the strength of the association of each with late events and the risk factors for each of these markers were compared. A postprocedural increase in creatinine was a more powerful predictor of late mortality than an increase in CK-MB. Risk factors for an increase in creatinine are similar to those for contrast-induced nephropathy, suggesting that vulnerability to such injury may identify patients with increased risk for late mortality.

Distal protection with a filter device during coronary stenting in patients with stable and unstable angina

BACKGROUND

Filter protection after percutaneous coronary intervention (PCI) is now available to prevent distal embolization. The aims of this study were (1) to evaluate the microembolization phenomenon during procedures of stent implantation in native coronary arteries of patients with stable and unstable angina, (2) to assess the amount and characteristics of the debris captured by the Angioguard, and (3) to investigate the relation between clinical and angiographic variables and pathological data.

METHODS AND RESULTS

Elective coronary stenting with the use of a protective filter was attempted in 39 consecutive coronary artery lesions with >60% stenosis (mean, 67.6+/-8.79%). Debris was present in 75.6% of the filters. Particle size ranged from 47.16 to 2503.48 microm (mean, 518.83+/-319.61 microm) in the major axis. Particles >300 microm were found in 24 of 28 filters with debris (85.7%), and particles >1000 microm were present in 10 of 28 filters (35.7%). Patients with unstable angina had greater particles (mean maximum longitudinal diameter, 1098.33+/-714.3 microm) than those with stable angina (412.91+/-453 microm; P<0.001). The presence of unstable angina (OR, 65; CI, 1.2 to 3420; P=0.03) and age >67 years (OR, 42; CI, 1 to 1698; P=0.04) were found to be the only independent predictors of embolic particle size.

CONCLUSIONS

By limiting embolization, protective devices may prevent a number of potentially unfavorable events, thereby improving outcome. Our data support the use of these devices, especially in lesions with higher embolic potential, such as those occurring in older patients and in those with unstable angina.

British Cardiac Society Working Group on the definition of myocardial infarction

The British Cardiac Society commissioned this report to help address inconsistencies in the terminology for acute coronary syndromes and wide variations in the threshold for the diagnosis of myocardial infarction (MI) depending on the assay performed, the precision, and the sensitivity. In addition, several publications have highlighted potential problems with the application of the European Society of Cardiology(ESC)/American College of Cardiology (ACC) consensus document published in 2000. A revision process has been initiated under the guidance of the ESC, the ACC, and the American Heart Association (AHA). The purpose of this report is to help inform the next revision of the ESC/ACC/AHA guidelines for the diagnosis of MI.

A prospective, randomised, single-blind pilot study to determine the effect of anaesthetic technique on troponin T release after off-pump coronary artery surgery

Ischaemic damage to the myocardium inevitably occurs during coronary artery surgery. However, the extent of the damage may be influenced by the anaesthetic technique used. The most sensitive and reliable marker of myocardial damage is currently thought to be troponin T. We conducted a prospective, randomised, single-blind pilot study to determine the baseline values of troponin T release after off-pump coronary artery bypass surgery in 30 patients randomly allocated to receive either propofol, isoflurane or isoflurane and high thoracic epidural analgesia. All other treatment was standardised. Patients undergoing emergency surgery and those with unstable angina were excluded. Blood samples were taken at 0, 3, 6, 12, 24 and 48 h after surgery for troponin T analysis. Mean troponin T levels at 24 h were not significantly different between the groups (p = 0.41). These data allows appropriate power calculations for further, large-scale studies to determine the anaesthetic technique that provides optimal myocardial protection.

Relation of final lumen dimensions in saphenous vein grafts after stent implantation to outcome

Larger final lumen dimensions after percutaneous coronary interventions in native coronary arteries lead to lower restenosis rates. We sought to determine the impact of stent expansion, as assessed by intravascular ultrasound, on clinical results of stent implantation in saphenous vein grafts (SVGs). We identified 226 consecutive patients who underwent intravascular ultrasound-guided stenting of 234 de novo SVG lesions. Patients were divided into 2 groups based on the final stent cross-sectional area (CSA): group I (stent CSA <100% of the reference lumen CSA, n = 176 patients, 182 lesions) and group II (stent CSA >/=100% of the reference lumen CSA, n = 50 patients, 52 lesions). Baseline patient characteristics were similar between the 2 groups with the exception of smaller lesions in group II. More aggressive stent expansion (group II) was associated with (1) increased rates of in-hospital non-Q-wave myocardial infarction (29% vs 17%, p = 0.05), (2) any myocardial infarction (26% vs 8%, p = 0.003) at 1-year follow-up, and (3) no improvement in target vessel revascularization at 1 year (31% vs 26%, p = 0.3). Aggressive stent expansion in SVG lesions resulted in higher myocardial infarction rates and, unlike native arteries, no improvement in target vessel revascularization rate at 1 year. A less aggressive stent implantation strategy in SVGs than in native coronary lesions appears prudent.

Usefulness of periprocedural creatinine phosphokinase-MB release to predict adverse outcomes after intracoronary radiation therapy for in-stent restenosis

We aimed to analyze periprocedural creatinine phosphokinase (CPK)-MB elevation in patients treated with intracoronary radiation therapy (IRT) for in-stent restenosis (ISR) to risk stratify these patients. The clinical significance of periprocedural CPK-MB elevation after IRT for ISR is unknown. An elevated CPK-MB has been associated with increased mortality after conventional angioplasty. We evaluated 1,326 patients who were enrolled in radiation trials for ISR at the Washington Hospital Center using gamma- and beta-emitters. Patients were analyzed according to degree of CPK-MB increase within 24 hours of the index IRT procedure (normal CPK-MB, CPK-MB 1 to 3 times the upper limit of normal, or CPK-MB >3 times the upper limit of normal). Patients with CPK-MB >3 times the upper limit of normal were older (64 +/- 12 years, p = 0.04), more likely to be smokers (64%, p = 0.04), hypertensive (85%, p <0.01), and diabetic (49%, p = 0.04). The cohort with the highest CPK-MB release (CPK-MB >3 times the upper limit of normal) had significantly higher rates of adverse clinical events at 12 months (major adverse cardiac events 40%, p <0.01), including death (9.3%, p <0.01) and late thrombosis (6.3%, p <0.01). Periprocedural CPK-MB elevation is of prognostic importance in patients treated with IRT for ISR, and its analysis appears to be mandatory to risk stratify these patients. The impact of glycoprotein IIb/IIIa antagonists in reducing periprocedural CPK-MB release awaits evaluation.

Comparison of frequency of hemorrhagic stroke in patients <75 years versus > or =75 years of age among patients receiving glycoprotein IIb/IIIa inhibitors during percutaneous coronary interventions

We identified 1,369 consecutive patients who received glycoprotein IIb/IIIa inhibitors during 1,461 stenting procedures (2,382 lesions); of these, 240 (17.5%) were aged > or =75 years (253 procedures, 430 lesions). Very elderly patients (> or =75 years) had similar in-hospital outcomes but a higher hemorrhagic stroke rate than patients aged <75 years.

Favorable effect of ?-radiation for in-stent restenosis: Effect of diabetes on angiographic and clinical outcomes

The purpose of this study was to examine the effect of vascular brachytherapy with gamma-radiation (gamma-RT) in patients with diabetes mellitus (DM) with coronary in-stent restenosis (ISR). In the Washington Radiation for In-Stent Restenosis (WRIST) trial, 130 patients with ISR were treated with (192)Ir or placebo. Of the patients enrolled, 44 (34%) had DM (18 of them treated with gamma-RT and 26 with placebo). Gamma-radiation therapy of ISR in diabetics resulted in similar procedural success and in-hospital outcome compared to nondiabetics. At 6-month follow-up, both DM and non-DM patients treated with gamma-RT had significantly lower target lesion revascularization (TLR), target vessel revascularization, and major adverse cardiac event rates compared to placebo. DM remains a powerful predictor of TLR and major adverse cardiac events even after treatment of ISR with gamma-RT.

Correlation of postpercutaneous coronary intervention creatine kinase-MB and troponin I elevation in predicting mid-term mortality

Creatine kinase-MB (CK-MB) and troponin I elevations after successful percutaneous coronary intervention (PCI) are common, and different gradations have been correlated with mortality. To establish which of these 2 markers of myonecrosis, CK-MB and troponin I, accurately predicts mortality after successful PCI, we analyzed 2,873 patients without acute myocardial infarction who underwent PCI for in-hospital events and mid-term mortality. Patients were stratified into 4 groups based on peak post-PCI cardiac markers values: group I: normal CK-MB (<16 U/L) or troponin I (<2 ng/ml); group II: CK-MB or troponin I levels 1 to 3 times normal; group III: >3 to 5 times normal; and group IV: >5 times normal. CK-MB elevation occurred in 16.1% of patients, with 12.2%, 2.3%, and 1.6% in groups II to IV, respectively. Troponin I elevation was detected in 38.9% of patients, with 16.4%, 8.4%, and 14.1% in groups II to IV, respectively. There was poor correlation between postprocedural CK-MB and troponin I values (r = 0.10) and in their individual subgroups. Kaplan-Meier estimates of death for postprocedure CK-MB were 2.1%, 2.7%, 1.7%, and 10.3% (p = 0.002) for groups I to IV, respectively; for troponin I, these estimates were 2.2%, 2.3%, 2.9%, and 2.1% for groups I to IV, respectively (p = 0.58). A Cox proportional hazards model showed that CK-MB >5 times normal was the strongest predictor of mortality (hazard ratio 6.7, 95% confidence interval 1.9 to 22.9; p = 0.002), although heart failure, peripheral vascular disease, pre-PCI digoxin therapy, and post-PCI renal failure also predicted mortality. However, neither troponin I peak elevation nor any subgroup predicted mortality. Troponin I is frequently elevated after PCI, but does not predict mortality. Periprocedural CK-MB elevation >5 times normal remains an independent predictor of mid-term mortality and a valuable marker for PCI prognosis in low-to-medium risk patients.

Patient care before and after percutaneous coronary artery interventions

Care of the patient before and after percutaneous coronary interventions has changed largely because of the increased use of stents. Important patient management issues include the evaluation of chest pain after the procedure, recognition of acute vessel closure during the periprocedural period, management of the vascular access site, and prevention of contrast-induced renal dysfunction. Risk factor modification and drug therapies are important interventions for the secondary prevention of coronary events. Functional testing has a meaningful role in the evaluation of some patients after coronary intervention. It is important for the specialist in internal medicine to have a firm working knowledge of the various aspects of patient care before and after these procedures because their role in the management of these patients is increasing.

Increased CK-MB release is a “trade-off” for optimal stent implantation

OBJECTIVES

We sought to determine the impact of aggressive stent expansion on creatine kinase-MB isoenzyme (CK-MB) release and clinical restenosis.

BACKGROUND

Elevation of CK-MB after percutaneous coronary interventions has been associated with late mortality.

METHODS

We identified 989 consecutive patients who underwent intravascular ultrasound-guided stenting of 1,015 coronary lesions. Patients were divided into three groups according to stent expansion, defined as the ratio of final lumen over the reference lumen cross-sectional areas: Group 1 (ratio <70%, n = 117 patients with 126 lesions); Group 2 (ratio 70% to 100%, n = 551 patients with 562 lesions); Group 3 (ratio >100%, n = 321 patients with 327 lesions).

RESULTS

The peak CK-MB values increased significantly with increasing stent expansion: CK-MB = 3 to 5x normal occurred 16%, 18%, and 25% in Groups 1, 2, and 3, respectively, p = 0.02; CK-MB >5 times normal occurred 9%, 13%, and 16% respectively, p = 0.02. Conversely, at one year follow-up there was a stepwise decrease in target lesion revascularization (11% vs. 19% and 17%, respectively, p = 0.04) and major adverse cardiac events with increasing stent expansion. In addition, there was a trend toward lower mortality in Group 3 (9% vs. 4.4% vs. 4.0%, p = 0.07).

CONCLUSIONS

Intravascular ultrasound-guided stent overexpansion (final lumen greater than reference lumen cross-sectional area) is accompanied by a higher periprocedural CK-MB release but a lower target lesion revascularization and a trend toward lower mortality at one year. Increased periprocedural CK-MB release appears as a trade-off for optimal stent implantation and lower clinical restenosis.

Optimal final lumen area and predictors of target lesion revascularization after stent implantation in small coronary arteries

Despite similar early clinical events, patients who undergo treatment of small vessels are at an increased risk for target lesion revascularization (TLR) after coronary artery stenting. We sought to determine predictors of TLR after stent implantation in small coronary arteries. We identified 423 consecutive patients who underwent intravascular ultrasound (IVUS)-guided small vessel stenting procedures in 465 coronary lesions with an angiographic reference vessel diameter of <2.75 mm. Patients were divided into 2 groups based on a final IVUS lumen area of < or =6.0 mm2 (n=345 lesions, group I) and >6.0 mm2 (n=115, group II). Baseline patient characteristics and in-hospital outcomes were similar between the 2 groups, except for a higher rate of restenotic lesions in group I and bifurcation lesions in group II. Group I had higher TLR rates at 1 year compared with group II patients (39% vs 26%, p = 0.02). The TLR rate appeared to decrease with greater stent expansion, especially at >90% of the reference vessel area, as assessed by IVUS. By multivariate analysis, an IVUS final stent area of < or =6 mm2, diabetes, absence of prior myocardial infarction, and history of intervention were independent predictors of 1-year TLR in this population. Final stent area of >6.0 mm2 and greater stent expansion were associated with a decrease in TLR. Therefore, there does not appear to be any "downside" to aggressive stent implantation strategies in small vessels. In contrast, IVUS allows maximization of final lumen dimensions to minimize clinical restenosis.