Prognostic implication of creatine kinase release after elective percutaneous coronary intervention in the pre-IIb/IIIa antagonist era

A Contemporary Definition of Periprocedural Myocardial Injury After Percutaneous Coronary Intervention of Chronic Total Occlusions

OBJECTIVES

The aim of this study was to assess the prognostic impact of post-procedural troponin T increase and mortality in patients undergoing percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) to define the threshold at which procedure-related myocardial injury drives mortality.

BACKGROUND

Coronary CTO recanalization represents the most technically challenging PCI. The complexity harbors a significant increased risk for complications with CTO PCI with compared with non-CTO PCI. However, there are evidenced biomarker cutoff levels that help identify those patients at risk for unfavorable clinical outcomes.

METHODS

A total of 3,712 consecutive patients undergoing PCI for at least 1 CTO lesion were enrolled, and comprehensive troponin T measurements were performed 6, 8, and 24 h after the procedure. All-cause mortality was defined as the primary study endpoint.

RESULTS

Using spline curve analysis, a more than 18-fold increase of troponin above the upper reference limit was significantly associated with mortality. In a Cox regression analysis, the crude hazard ratio was 2.32 (95% confidence interval: 1.83 to 2.93; p < 0.001) for a ≥18-fold increase compared with patients with post-procedural troponin increase <18-fold of the upper reference limit. Results remained virtually unchanged after bootstrap- or clinical confounder-based adjustment.

CONCLUSIONS

This large-scale outcome study demonstrates for the first time the prognostic value of post-procedural troponin T elevation after PCI in patients with CTOs. A threshold was defined for procedure-related myocardial injury in patients with CTOs to differentiate them from those without CTOs that may help guide post-procedural clinical care in this high-risk patient population.

Mortality impact of post-discharge myocardial infarction size after percutaneous coronary intervention: a patient-level pooled analysis from the 4 large-scale Japanese studies

It is unknown whether there is a threshold of creatine kinase (CK) or CK-MB affecting the subsequent mortality for post-discharge myocardial infarction (PDMI) after percutaneous coronary intervention. Current study sought to evaluate the impact of PDMI. The study population included 30,051 patients with successful coronary stenting and discharged alive in the pooled patient-level database of 4 Japanese studies (j-Cypher registry, CREDO-Kyoto PCI/CABG registry cohort-2, RESET, and NEXT). During 4.4 ± 1.4 year follow-up, 915 patients experienced PDMI (cumulative 5-year incidence of 3.6%). Among 466 patients with available peak CK ratio (peak CK/upper limit of normal), peak CK ratio (< 3) was present in 21% of patients, while peak CK ratios (≥ 3 and < 5), (≥ 5 and < 10), (≥ 10 and < 30), and (≥ 30) were present in 17, 25, 30, and 7.3% of patients, respectively. The excess mortality risk of patients with relative to those without PDMI for subsequent mortality was significant (adjusted HR 5.12, 95% CI 4.52-5.80, P < 0.001) by the Cox model with PDMI incorporated as the time-updated covariate. However, the mortality risk of patients in the smallest peak CK ratio category (< 3) was insignificant (HR 0.85, 95% CI 0.43-1.71, P = 0.65). In conclusion, despite significant overall mortality risk of PDMI, the mortality risk of small PDMI was similar to that of no PDMI, suggesting the presence of some threshold about infarct size influencing mortality.Trial registrations The Randomized Evaluation of Sirolimus-Eluting Versus Everolimus-Eluting Stent Trial (RESET); NCT01035450 and NOBORI Biolimus-Eluting Versus XIENCE/PROMUS Everolimus-Eluting Stent Trial (NEXT); NCT01303640. J-Cypher and CREDO-Kyoto PCI/CABG registry cohort 2 were not registered into clinical trial database.

Incidence, predicting factors, and clinical outcomes of periprocedural myocardial infarction after percutaneous coronary intervention for chronic total occlusion in the era of new-generation drug-eluting stents

OBJECTIVE

This study aimed to examine predictors and clinical outcomes of periprocedural myocardial infarction (PMI) after chronic total occlusion (CTO) intervention.

BACKGROUND

There are limited data on the clinical implications of PMI after CTO intervention in the new-generation drug-eluting stent (DES) era.

METHODS

We enrolled 337 patients who underwent CTO intervention and met the study criteria. We evaluated the incidence and predictors of PMI, defined as an increase in creatine kinase-MB ≥3× the upper limit of normal (ULN) after intervention and compared the occurrence rates of major adverse cardiac and cerebrovascular events (MACCE, defined as the composite of cardiac death, myocardial infarction, stent thrombosis, target-vessel revascularization, or cerebrovascular accidents) between the PMI and non-PMI groups.

RESULTS

PMI occurred in 23 (6.8%) patients after CTO intervention. Significant independent predictors were previous bypass surgery [odds ratio (OR) = 5.52, 95% confidence interval (CI) = 1.17-25.92; P = 0.03], Japan-CTO score ≥3 (OR = 7.06, 95%CI = 2.57-19.39; P < 0.001), side branch occlusion (OR = 4.21, 95%CI = 1.13-15.66; P = 0.03), and longer procedure time (OR = 4.18, 95%CI = 1.35-12.99; P = 0.01). During a median follow-up of 29.6 months, the PMI group had a significantly higher MACCE rate than the non-PMI group (23.7 vs. 5.6%, P = 0.008 by log-rank test). PMI was an independent predictor of MACCE (HR = 4.26, 95%CI = 1.35-13.43; P = 0.01). The MACCE rate gradually increased in a CK-MB-dependent fashion and was highest in patients with ≥10× ULN (P = 0.005).

CONCLUSION

Previous bypass surgery, high Japan-CTO score, side branch occlusion, and longer procedure time were strongly related to PMI occurrence after CTO intervention. PMI was significantly associated with worse clinical outcomes in the new-generation DES era.

Diagnostic Accuracy of Post Procedural Creatine Kinase, MB Form can Predict Long-Term Outcomes in Patients Undergoing Selective Percutaneous Coronary Intervention?

Background:

Measuring cardiac markers in blood has been the main strategy for the diagnosis of acute myocardial infarction for nearly 50 years. Creatine kinase-MB (CK-MB) has been demonstrated to be a highly specific marker.

Objectives:

The present study aimed to assess the role of CK-MB changes following percutaneous coronary intervention (PCI) to predict one year outcomes of this procedure.

Patients and Methods:

This cohort study was conducted on 138 patients diagnosed with coronary artery disease who underwent PCI. Sixty-nine patients who had a CK-MB elevation ≥ 3 times upper limit of normal (ULN) post procedurally were considered as group I and 69 patients without cardiac enzyme rise after PCI were considered as the control group (group II). The composite end point of major adverse cardiac events (MACE) during one year was assessed by telephone follow-up or presentation at clinical visiting, and compared between the two groups. The MACE was defined as the appearance of at least one of the following events: mortality, repeated revascularization procedures, myocardial infarction, or cerebrovascular events.

Results:

Although one year mortality in the group I was 4 (5.8%), about two times greater than the other group 2 (2.9%), the difference was not significantly discrepant (P = 0.57). Moreover, 8 (11.6%) of patients in group I experienced one year MACE, while this rate in the other group was 4 (5.8%), with insignificant difference (P = 0.22). In group I, one case experienced coronary artery bypass surgery, one, exhibited cerebrovascular disease and one reported ST segment elevation myocardial infarction (STEMI), while two patients in the other group were suspicious of having non-ST segment elevation myocardial infarction (NSTEMI) and candidates for repeated PCI. Multivariate analysis revealed that increased post-procedural CK-MB ≥ 3 times UNL could not predict long-term MACE in patients who underwent selective PCI. Area under the curve (AUC) for predicting one year MACE was 0.593 (95% CI: 0.397 - 0.788), indicating inappropriate accuracy for this biomarker (P = 0.290).

Conclusions:

It seems that CK-MB ≥ 3 times ULN within 24 hours after PCI cannot independently predict one year MACE in patients undergoing PCI.

Myocardial ischemia is a key factor in the management of stable coronary artery disease

Previous studies demonstrated that coronary revascularization, especially percutaneous coronary intervention (PCI), does not significantly decrease the incidence of cardiac death or myocardial infarction in patients with stable coronary artery disease. Many studies using myocardial perfusion imaging (MPI) showed that, for patients with moderate to severe ischemia, revascularization is the preferred therapy for survival benefit, whereas for patients with no to mild ischemia, medical therapy is the main choice, and revascularization is associated with increased mortality. There is some evidence that revascularization in patients with no or mild ischemia is likely to result in worsened ischemia, which is associated with increased mortality. Studies using fractional flow reserve (FFR) demonstrate that ischemia-guided PCI is superior to angiography-guided PCI, and the presence of ischemia is the key to decision-making for PCI. Complementary use of noninvasive MPI and invasive FFR would be important to compensate for each method's limitations. Recent studies of appropriateness criteria showed that, although PCI in the acute setting and coronary bypass surgery are properly performed in most patients, PCI in the non-acute setting is often inappropriate, and stress testing to identify myocardial ischemia is performed in less than half of patients. Also, some studies suggested that revascularization in an inappropriate setting is not associated with improved prognosis. Taken together, the presence and the extent of myocardial ischemia is a key factor in the management of patients with stable coronary artery disease, and coronary revascularization in the absence of myocardial ischemia is associated with worsened prognosis.

Percutaneous coronary intervention in treatment of multivessel coronary artery disease in patients with non-ST-segment elevation acute coronary syndrome

Among patients with non-ST-elevated acute coronary syndromes (NSTE-ACS) the estimated percentage of single vessel coronary artery disease (SV-CAD) observed during coronarography is about 20-40%, while multivessel coronary artery disease (MV-CAD) is found in about 40-60%. Further treatment in patients with both SV CAD and MV CAD is usually culprit vessel percutaneous coronary intervention (CV-PCI). Nevertheless, in the group of patients with MV-CAD there is still a problematic decision whether the non-infarct related arteries (non-IRA) should be treated with PCI. According to the European Society of Cardiology (ESC) guidelines on myocardial revascularization this decision should be based on the overall clinical and angiographic status of the patient; simultaneously they suggest performing ad hoc CV-PCI. The decision of performing intervention in the rest of the narrowed coronary arteries should be made after consultation with the heart team or according to the protocols adopted in the specific clinic. Furthermore, there is a question of whether the procedure should be performed immediately after culprit vessel revascularization or it should be postponed until the patient is stabilized. Due to the lack of specific recommendations we decided to perform an analysis of existing studies which compared culprit versus multivessel revascularization in patients with MV-CAD and non-ST-elevated acute coronary syndromes.

Association between proximal stent edge positioning on atherosclerotic plaques containing lipid pools and postprocedural myocardial infarction (from the CLI-POOL Study)

Postprocedural myocardial infarction is an ominous complication of percutaneous coronary intervention (PCI). Despite several patient, lesion, and procedural factors that may affect its occurrence and severity, it is unclear if implanting a stent edge on a coronary lipid pool, as appraised by optical coherence tomography (OCT), adversely affects outcomes. The aim of this study was to assess the association between postprocedural myocardial infarction and the implantation of a stent edge on a lipid pool, as assessed by OCT. A database was screened for patients without ongoing myocardial infarctions; who underwent PCI with stenting for single, native, de novo lesions; without periprocedural side-branch occlusion or compromise; who underwent post-PCI OCT; and had postprocedural myocardial infarctions. These subjects were matched 1:1 with patients with similar features but without postprocedural myocardial infarctions. Plaque characterization with OCT was performed using established criteria. Specifically, lipid pools within stent edges were quantified by computing the number of involved quadrants and the degree of lipid arc on cross-sectional images. A total of 30 patients were included (15 with postprocedural myocardial infarctions and 15 controls without infarctions). Whereas no patient or control subject had lipid pools in correspondence to distal stent edges, landing of proximal stent edges on lipid pools was significantly more frequent in patients than in controls (10 [66%] vs 2 [13%], p = 0.009), Moreover, patients with postprocedural myocardial infarctions had more extensive lipid pools at proximal stent edges than those without postprocedural myocardial infarctions. Accordingly, lipid pool arc at proximal stent edge was significantly associated with peak post-PCI creatine kinase-MB/upper limit of normal ratio (Spearman's ρ = 0.49, p = 0.006). In conclusion, incomplete stent coverage of coronary lipid pools appears to be associated with an increased risk for postprocedural myocardial infarction in patients who undergo PCI.

Impact of drug eluting stent length on outcomes of percutaneous coronary intervention (from the EVENT registry)

In randomized trials, longer drug-eluting stent (DES) length has been associated with adverse clinical events. We used data from the EVENT registry to examine the impact of DES length on outcomes in routine clinical practice. We identified 5,425 unselected consecutive patients from the EVENT registry who had a single vessel treated with DES for nonemergency indications from 2004 through 2007. The association between stented length and short- and long-term outcomes was analyzed in ordinal categories (<15, 15 to 19, 20 to 24, and >24 mm) and as a continuous variable. There were few differences in baseline characteristics across categories. At 1 year, there was a stepwise increase in major adverse cardiac events (composite of death, myocardial infarction [MI], and target lesion revascularization [TLR]) with increasing stent length (8.0%, 10.1%, 11.8%, and 14.8%, p <0.001) and a similar relation with TLR (3.0%, 3.1%, 3.3%, and 5.0%, p = 0.02). After adjusting for demographic, clinical, angiographic, and treatment characteristics, longer stent length remained associated with 1-year major adverse cardiac events (adjusted hazard ratio 1.17 per 10-mm increase stent length) and TLR (hazard ratio 1.20 per 10 mm), but not with stent thrombosis. In conclusion, longer DES length is associated with increased adverse events, predominantly periprocedural MI, but also an increased rate of TLR.

Troponin I and Creatine Kinase MB do not provide comparable information after PCI

OBJECTIVES

To compare cardiac troponin I (cTnI) and creatine kinase-MB (CK-MB) after PCI in cases with normal baseline levels of both biomarkers.

DESIGN

cTnI and CK-MB after PCI were stratified as multiples of the 99(th) percent upper reference limit (99%URL) and compared to each other in 489 patients. Post-PCI levels > three times 99%URL were classified as procedure-related infarctions. Results. After PCI, CK-MB was > 3x 99%URL in 58/486 patients (12%) and cTnI > 3x 99%URL in 292/487 patients (60%). cTnI was > 10x 99%URL in all cases with infarction according to CK-MB but CK-MB was often normal despite elevated cTnI. There was an only minimal overlap between two infarction populations, those with cTnI in the range from 1x to 10x 99%URL and those with CK-MB 1x to 10x 99%URL.

CONCLUSIONS

With the present quantification scales, infarction rate after PCI is > five-fold higher with cTnI than with CK-MB.

The Highway Technique: a new stenting technique to treat coronary bifurcation lesions

AIMS

We report a new stenting technique which was employed in 12 patients to treat coronary bifurcation lesions.

METHODS AND RESULTS

A stent is positioned in the main vessel together with a balloon in the side branch, which is positioned slightly proximal to the main vessel stent that also has enough length to cover the side branch ostium. Both the stent in the main vessel and the balloon in the side branch are inflated simultaneously. Following deflation, a double lumen is created in the main vessel, proximal to the bifurcation. The stent balloon is removed with the side branch balloon left deflated in its initial position. The main vessel is rewired with a third guidewire. The side branch balloon and guidewire are removed. The initial guidewire in the main vessel is directed to the side branch. A balloon is advanced and inflated in the side branch to dilate the struts of the main vessel stent that will provide the side branch entrance. The side branch balloon is left in place. A size matched balloon is advanced on the third guidewire that was advanced in the main vessel and inflated inside the stent with high pressure. Finally, kissing balloon inflation is performed at the bifurcation. Provisional stenting of the side branch can be performed when necessary. Final kissing balloon inflation is recommended after stenting of the side branch.

CONCLUSIONS

As a new coronary bifurcation stenting method, the Highway Technique has some advantages in side branch protection, with favourable immediate and 30-day clinical outcomes.

Prognostic value of troponin after elective percutaneous coronary intervention: A meta-analysis

BACKGROUND

Although the prognostic importance of troponin in patients with anacute coronary syndrome is clear, the significance of troponin elevation after elective percutaneous coronary intervention (PCI) is a subject of debate. However, most studies up to now had a small sample size and insufficient events during follow-up.

METHODS

Electronic and manual searches were performed of studies reporting on prognosis of troponin after elective PCI. A meta-analysis was done of all suitable studies, with death in follow-up as primary endpoint and the combination of death or nonfatal myocardial infarction in follow-up as secondary endpoint.

RESULTS

20 studies involving 15,581 patients were included. These studies were published between 1998 and 2007. Overall, troponin was elevated after elective PCI in 32.9% of patients. The follow-up period varied between 3 and 67 months (mean 16.3). Increased mortality was significantly associated with troponin elevation after PCI (4.4% vs. 3.3%, P = 0.001; OR 1.35). Furthermore, the combined endpoint of mortality or nonfatal myocardial infarction also occurred more often in patients with post-procedural troponin elevation (8.1% vs. 5.2%, P < 0.001; OR 1.59).

CONCLUSIONS

According to this meta-analysis, troponin elevation after elective PCI provides important prognostic information.

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.

Does pravastatin therapy affect cardiac enzyme levels after percutaneous coronary intervention?

Serum cardiac enzyme elevation after percutaneous coronary intervention (PCI), a relatively common complication, is a prognostic determinant of long-term outcome in patients who undergo these procedures. Statins are postulated to reduce such complications. This study investigated the short-term effects of pravastatin on serum creatine kinase myocardial isoform (CK-MB) and serum cardiac troponin I (cTpI) levels after elective PCI. Of 93 patients studied, 72 (77.4%) were men, and 21 (22.6%) were women (mean age, 58.9+/-11.0 y). Patients were randomly divided into 3 groups before they underwent elective PCI. Preoperatively, group 1 patients (n=30) received pravastatin 10 mg/d, and group 2 patients (n=29) received pravastatin 40 mg/d. Control group patients (n=34) received no lipid-lowering medication. Serum CK-MB and serum cTpI levels were measured preoperatively and then again at 6, 24, and 36 h postoperatively. Demographic features of patients and characteristics of the PCI procedure, including number of vessels/lesions and duration and number of inflations, did not differ among groups (P>.05). Mean serum CK-MB and serum cTpI levels were significantly increased after PCI in all patients (P<.001). When compared with control group patients, those given pravastatin did not experience significantly lowered postprocedural serum CK-MB or serum cTpI levels (P>.05). Preprocedural pravastatin therapy at dosages of 10 mg/d and 40 mg/d seems inadequate for preventing serum cardiac enzyme elevations during short-term follow-up after PCI. Additional research on this topic is recommended.

The effect of mannitol on oxygenation and creatine kinase MB release in patients undergoing multivessel off-pump coronary artery bypass surgery

OBJECTIVES

Despite avoiding cardiopulmonary bypass, off-pump coronary artery bypass surgery is associated with reduction in PaO2 and postoperative respiratory compliance. Also, transient interruption of coronary flow is necessary during distal anastomoses and may impose ischemia-reperfusion myocardial injury. Mannitol is an osmotic diuretic with free radical scavenging properties, and we have evaluated the effects of mannitol on oxygenation and cardiac enzyme release in patients undergoing multivessel off-pump bypass surgery in a prospective, randomized, controlled, double-blind trial.

METHODS

Fifty patients were randomly allocated to receive either 20% mannitol 0.5 g/kg (n = 25) or normal saline 2.5 mL/kg (n = 25) during Y-graft construction. Pulmonary variables and serum sodium concentrations were measured 15 minutes after induction of anesthesia and sternum closure. Creatine kinase MB was measured before and after the operation. Intraoperative and postoperative fluid input and output, time to extubation, and intraoperative hemodynamic variables were also recorded.

RESULTS

PaO2 after sternum closure was significantly higher in the mannitol group, with faster time to extubation and shorter length of stay in the intensive care unit. Intraoperative urine output was significantly greater in the mannitol group, without significant differences in fluid input, serum sodium concentration, and hemodynamic variables. Number of patients with a creatine kinase MB level more than 3 times the upper limit of normal was significantly higher in the control group.

CONCLUSION

Mannitol could be safely used without adverse side effects in patients undergoing multivessel off-pump bypass surgery with beneficial effects in terms of preserving oxygenation, earlier extubation, and fewer patients with significant creatine kinase MB elevation.

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.

Long-Term Cost Effectiveness of Early and Sustained Dual Oral Antiplatelet Therapy With Clopidogrel Given for Up to One Year After Percutaneous Coronary Intervention

OBJECTIVES

This study sought to evaluate the long-term cost effectiveness of a clopidogrel loading strategy before percutaneous coronary intervention (PCI) followed by continued treatment for one year.

BACKGROUND

The Clopidogrel for the Reduction of Events During Observation (CREDO) trial, a randomized trial of 2,116 patients, showed the effectiveness of antiplatelet therapy with clopidogrel 300 mg before PCI and 75 mg daily for one year afterward compared with placebo load and placebo days 29 to 365 in reducing the combined risk of death, myocardial infarction, and stroke. All patients received clopidogrel on days 1 to 28 and aspirin on days 1 to 365.

METHODS

All hospitalizations were assigned a diagnosis-related group. Associated costs were estimated three ways (including professional costs): 1) Medicare costs, 2) MEDSTAT costs, and 3) blend with Medicare for those age > or = 65 years and MEDSTAT for those age <65 years. Clopidogrel 75 mg cost 3.22 dollars. Life expectancy in trial survivors was estimated using external data. Confidence intervals were assessed by bootstrap.

RESULTS

The primary composite end point occurred in 89 (8.45%) clopidogrel patients and in 122 (11.48%) placebo patients (relative risk reduction [RRR] 26.9%; 95% confidence interval [CI] 3.9% to 44.4%). The number of life-years gained (LYG) with clopidogrel was 0.1526 (95% CI 0.0263 to 0.2838) using Framingham data and 0.1920 (95% CI 0.054 to 0.337) using Saskatchewan data. Average total costs were 664 dollars higher for the clopidogrel arm (95% CI -461 dollars to 1,784 dollars). The incremental cost-effectiveness ratios (ICERs) based on Framingham data ranged from 3,685 dollars/LYG to 4,353 dollars/LYG, with over 97% of bootstrap-derived ICER estimates below 50,000 dollars/LYG. The ICERs based on Saskatchewan data were 2,929 dollars/LYG to 3,460 dollars/LYG, with over 98% of estimates below 50,000 dollars/LYG.

CONCLUSIONS

Platelet inhibition with clopidogrel loading before PCI followed by therapy for one year is highly cost effective.

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.

Long-term cost-effectiveness of clopidogrel given for up to one year in patients with acute coronary syndromes without ST-segment elevation

OBJECTIVES

We sought to evaluate the long-term cost-effectiveness of clopidogrel for up to one year after an acute coronary syndrome (ACS) without ST-segment elevation.

BACKGROUND

The efficacy of platelet inhibition with clopidogrel for up to one year after ACS was demonstrated in the Clopidogrel in Unstable angina to prevent Recurrent Events (CURE) trial, a randomized trial of 12,562 patients in 28 countries that was conducted between 1998 and 2000. Patients were given clopidogrel (300-mg load followed by 75 mg/day) versus placebo, both in addition to aspirin, for a mean of nine months.

METHODS

We used patient-level clinical outcomes and resource use from the CURE trial and estimates of life expectancy gains as a result of the prevention of the clinical events of death, stroke, and myocardial infarction on the basis of data from external sources.

RESULTS

Excluding clopidogrel costs, average costs of hospitalizations alone were 325 dollars less for the clopidogrel arm (95% confidence interval -722 dollars to 45 dollars) using diagnosis-related group-based Medicare reimbursement rates. When including clopidogrel costs (766 dollars greater for the clopidogrel arm), average total costs were 442 dollars higher for the clopidogrel arm (95% confidence interval 62 dollars to 820 dollars). The incremental cost-effectiveness ratio (ICER) on the basis of the Framingham Heart Study was 6,318 dollars per life-year gained (LYG) with clopidogrel, with 94% of bootstrap-derived ICER estimates <50,000 dollars/LYG; based on Saskatchewan, the ICER was 6,475 dollars/LYG with 98% of estimates <50,000 dollars.

CONCLUSIONS

Platelet inhibition with clopidogrel in patients for up to one year after presentation with an acute coronary syndrome is both effective and cost-effective.

Impact of major side branch on periprocedural enzyme elevation and long-term outcome in patients undergoing percutaneous coronary intervention and brachytherapy for in-stent restenosis

Side branch occlusion is 1 mechanism for the increase of creatine phosphokinase-MB after percutaneous coronary intervention and is associated with long-term adverse events. We studied 248 patients who underwent brachytherapy for in-stent restenosis with and without side branches, compared levels of creatine phosphokinase-MB with procedural, in-hospital, and long-term clinical outcomes, and found that patients with side branches have increased levels of creatine phosphokinase-MB after percutaneous coronary intervention and higher rates of restenosis, target vessel, and target lesion revascularization at 6-month follow-up.