Relation of minor cardiac troponin I elevation to late cardiac events after uncomplicated elective successful percutaneous transluminal coronary angioplasty for angina pectoris

The clinical approach to diagnosing peri-procedural myocardial infarction after percutaneous coronary interventions according to the fourth universal definition of myocardial infarction - from the study group on biomarkers of the European Society of Cardiology (ESC) Association for Acute CardioVascular Care (ACVC)

PURPOSE

This review intends to illustrate basic principles on how to apply the Fourth Universal Definition of Myocardial Infarction (UDMI) for the diagnosis of peri-procedural myocardial infarction (MI) after percutaneous coronary interventions (PCI) in clinical practice.

METHODS AND RESULTS

Review of routine case-based events. Increases in cardiac troponin (cTn) concentrations are common after elective PCI in patients with chronic coronary syndrome (CCS). Peri-procedural PCI-related MI (type 4a MI) in CCS patients should be diagnosed in cases of major peri-procedural acute myocardial injury indicated by an increase in cTn concentrations of >5-times the 99th percentile upper reference limit (URL) together with evidence of new peri-procedural myocardial ischaemia as demonstrated by electrocardiography (ECG), imaging, or flow-limiting peri-procedural complications in coronary angiography. Measurement of cTn baseline concentrations before elective PCI is useful. In patients presenting with acute MI undergoing PCI, peri-procedural increases in cTn concentrations are usually due to their index presentation and not PCI-related, apart from obvious major peri-procedural complications, such as persistent occlusion of a large side branch or no-reflow after stent implantation.

CONCLUSION

The distinction between type 4a MI, PCI-related acute myocardial injury, and chronic myocardial injury can be challenging in individuals undergoing PCI. Careful integration of all available clinical data is essential for correct classification.

Determinants of Periprocedural Myocardial Infarction in Current Elective Percutaneous Coronary Interventions

Periprocedural myocardial infarction (PMI) is closely associated with long-term cardiovascular events. The factors associated with PMI are not fully understood. The purpose of this study was to investigate the determinants of PMI in contemporary elective percutaneous coronary intervention (PCI). Overall, 731 elective PCI was divided into the PMI (n = 27) and non-PMI (n = 704) groups. Univariate and multivariate logistic regression analysis was used to find factors associated with PMI. In the univariate analysis, PMI was associated with complex lesion characteristics, such as the lesion length, lesion angle, calcification, and Medina classification. In the multivariate logistic regression analysis, the lesion length (per 10-mm increase: odds ratio (OR), 1.477; 95% confidence interval (CI), 1.161‒1.879; P = 0.002), lesion angle ≥ 45° (versus lesion angle < 45°: OR, 4.244; 95% CI, 1.187‒15.171; P = 0.026), and Medina classification (0,1,1) / (1,1,1) (versus other lesions: OR, 14.843; 95% CI, 6.235‒35.334; P < 0.001) were significantly associated with PMI. Of the 24 lesions with lesion angle ≥ 45° in the PMI group, 14 had final TIMI flow grade ≤ 2 in side branches and 9 had transient slow flow in main branches/transient ST elevation during PCI. Of the 87 lesions with Medina classification (1,1,1) / (0,1,1), 19 had final TIMI grade ≤ 2 in side branches. In conclusion, the lesion length, lesion angle ≥ 45°, and Medina classification (0,1,1) / (1,1,1) were significantly associated with PMI in contemporary elective PCI. Preventing flow limitation in both side branches and main vessels in elective PCI for the diffuse long, angulated, or true bifurcation lesions is important.

Periprocedural Myocardial Injury: Pathophysiology, Prognosis, and Prevention

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

Periprocedural elevated myocardial biomarkers and clinical outcomes following elective percutaneous coronary intervention: a comprehensive dose-response meta-analysis of 44,972 patients from 24 prospective studies

AIMS

The optimal cut-off value of isolated cardiac biomarker elevation for defining prognostically important percutaneous coronary intervention (PCI)-related myocardial injury is not known. We performed a meta-analysis to evaluate the dose-response relationship between isolated cardiac biomarker elevations and the risk of all-cause mortality following elective PCI.

METHODS AND RESULTS

Twenty-four prospective studies (44,972 patients) were included. Patients with an isolated elevation of cardiac biomarkers had an increased risk of all-cause mortality when compared to those with no elevations (cardiac troponin I: odds ratio [OR] 1.42, 95% confidence interval [CI]: 1.19-1.69; creatine kinase-MB isoenzyme [CK-MB]: OR 1.43, 95% CI: 1.19-1.70). For the dose-response analysis, elevations of cardiac troponin I >3x or CK-MB >1x the 99th percentile upper reference limit (URL) were associated with increased mortality (cardiac troponin I: OR 1.51, 95% CI: 1.05-2.17; CK-MB: OR 1.25, 95% CI: 1.05-1.48). The pooled OR of mortality for each 3xURL increment of cardiac troponin I or CK-MB was 1.33 (95% CI: 1.15-1.53) and 1.38 (95% CI: 1.30-1.47).

CONCLUSIONS

We found that a positive dose-response relationship between isolated cardiac troponin I and CK-MB with all-cause mortality and elevated cardiac troponin I >3x or CK-MB >1x the 99th percentile URL was associated with an increased risk of mortality.

Prevention of minor myocardial injury after elective percutaneous coronary intervention: comparison of ticagrelor versus clopidogrel

BACKGROUND

Elective percutaneous coronary intervention (ePCI) may cause minor elevation of cardiac enzymes, so-called minor myocardial injury (MMI) which can be due to different pathophysiological mechanism (e.g. distal embolisation, side branch occlusion, increased platelet activation triggered by the intracoronary metallic stents). We aimed to compare the effectiveness of ticagrelor versus clopidogrel for the prevention of MMI and major adverse clinical events (MACEs) after ePCI.

METHODS

Study population consisted of two groups of patients based on the treatment: Group I, receiving clopidogrel (n = 104), Group II, receiving ticagrelor (n = 96). Cardiac troponin I (cTnI), CK-MB were studied before and 12 hours after the procedure. Elevation of cTnI greater than 0.06 ng/ml was considered as MMI. All patients were also evaluated for the MACEs (death, myocardial infarction, stroke and transient ischaemic attack).

RESULTS

Fifty-two of 200 patients (26%) had MMI after the procedure. The minor myocardial injury was significantly more prevalent in clopidogrel group than that of ticagrelor group (33% vs. 19%, p = .03). Myocardial infarction (MI) and MACEs were significantly higher in the clopidogrel group (15% vs. 6%, for MI, p = .04; 16% vs. 6%, for MACEs, p = .03, respectively). Multivariate analysis demonstrated antiplatelet treatment, saphenous graft intervention, type-C lesion as independent predictors of MMI.

CONCLUSIONS

Present study showed that the combination of ticagrelor and aspirin was more effective than combination of clopidogrel and aspirin in decreasing MMI and MACEs after elective stenting.

Cardiac Troponin I Increase After Successful Percutaneous Coronary Angioplasty: Predictors and Long-Term Prognostic Value

After successful percutaneous coronary interventions (PCI), elevations of cardiac enzymes are not rare, but it is still not clear whether those elevations are associated with adverse late outcome. The purpose of the study was to investigate the relation between cardiac troponin I (cTn-I) increase after successful percutaneous intervention and late outcome. The study consisted of 100 consecutive patients (mean age 56 ±9.8, 84% male) who had successful elective coronary balloon angioplasty with or without stent implantation. Patients with stable angina (n=54) and unstable angina (n=46) were included in the study. Blood samples for measurement of cTn-I were taken before and immediately after the procedure, and every 6 hours for the first 24 hours. Patients with preprocedural cTn-I elevation were excluded from the study. Postprocedural cTn-I elevation was detected in 34 patients (34%, troponin (+) group) and cTn-I levels were normal in 66 patients (66%, troponin (-) group). Logistic regression analysis showed that intervention in patients with unstable angina, stent implantation following balloon dilation, and maximal inflation pressure were the predictors of cTn-I elevation (p=0.035, p=0.038, and p=0.014, respectively). During the prospective follow-up period for 21 ±7.5 months, the incidence of major cardiac events including recurrent angina, acute myocardial infarction, death, and revascularization were not different in patients with and without cTn-I elevation. Overall, major cardiac events occurred in 9 patients (26%) in the troponin (+) group and in 13 patients (20%) in the troponin (-) group. Kaplan-Meier survival analysis showed that cTn-I elevation was not an important correlate of overall cardiac events (log-rank: 1.66, p=0.19). The authors conclude that postprocedural cTn-I elevation is related to unstable angina, stent implantation following predilation, and inflation pressure, and there is no association with minor myocardial injury occurring after successful percutaneous coronary intervention and late adverse cardiac events.

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

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

Multimarker risk stratification approach and cardiovascular outcomes in patients with stable coronary artery disease undergoing elective percutaneous coronary intervention

AIMS

We studied the utility of multimarker risk stratification approach to predict cardiovascular outcomes in patients with stable coronary artery disease, undergoing elective percutaneous coronary intervention (PCI).

METHODS

We prospectively evaluated 302 consecutive patients with stable coronary artery disease and normal CPK-MB and cardiac troponin T levels, and who underwent elective PCI at our institution. The following cardiac biomarkers were measured before and between 12 and 24h post-procedure: CK-MB, cardiac troponin T, hs-CRP, and NT-ProBNP. Patients were followed up for a minimum of 6 months.

RESULTS

Post-PCI, CPK-MB levels were elevated but below myocardial infarction (MI) range in 70 patients (23%), and in the MI range in 6 patients (2%). Troponin T levels were detectable but below the 99th percentile (microleak) in 32 patients (10.6%) and elevated above the 99th percentile (periprocedural MI) in 104 patients (34.4%). At 9 months' follow-up, 1% died, 2% had stable angina, 10.3% had non-fatal MI, and 87.7% remained asymptomatic. There was no significant difference in clinical events among groups stratified by elevation of one biomarker or multiple biomarkers.

CONCLUSION

Single or multiple biomarker strategy in patients with normal baseline biomarkers failed to predict major cardiac events after PCI over medium-term follow-up.

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.

Consideration of a new definition of clinically relevant myocardial infarction after coronary revascularization: an expert consensus document from the Society for Cardiovascular Angiography and Interventions (SCAI)

Numerous definitions have been proposed for the diagnosis of myocardial infarction (MI) after coronary revascularization. The universal definition for MI designates post procedural biomarker thresholds for defining percutaneous coronary intervention (PCI)-related MI (type 4a) and coronary artery bypass grafting (CABG)-related MI (type 5), which are of uncertain prognostic importance. In addition, for both the MI types, cTn is recommended as the biomarker of choice, the prognostic significance of which is less well validated than CK-MB. Widespread adoption of a MI definition not clearly linked to subsequent adverse events such as mortality or heart failure may have serious consequences for the appropriate assessment of devices and therapies, may affect clinical care pathways, and may result in misinterpretation of physician competence. Rather than using an MI definition sensitive for small degrees of myonecrosis (the occurrence of which, based on contemporary large-scale studies, are unlikely to have important clinical consequences), it is instead recommended that a threshold level of biomarker elevation which has been strongly linked to subsequent adverse events in clinical studies be used to define a "clinically relevant MI." The present document introduces a new definition for "clinically relevant MI" after coronary revascularization (PCI or CABG), which is applicable for use in clinical trials, patient care, and quality outcomes assessment.

Early invasive strategy and outcomes of non-ST-elevation acute coronary syndrome patients: is time really the major determinant?

In non-ST-elevation acute coronary syndromes (ACS), an early invasive strategy is recommended for middle/high-risk patients; however, the optimal timing for coronary angiography is still debated. The aim of this study was to evaluate the prognostic implications of the time of angiography in ACS patients treated in accord with an early invasive strategy. We analyzed the relationship between the time of angiography and outcomes at follow-up in 517 ACS patients, of whom 482 were revascularized with percutaneous coronary intervention (PCI) (86.9%) or coronary artery by-pass graft (13.1%). We also evaluated the influence of clinical, biohumoral and angiographic variables on the patients' outcomes at follow-up. Among patients submitted to angiography at different time intervals from both hospital admission and symptom onset, significant differences neither in mortality nor in cardiac ischemic events at follow-up were observed. At univariate analysis, complete versus partial revascularization, longer hospital stay, higher TIMI risk score, diabetes mellitus, higher discharge creatinine and admission anemia were associated with mortality and cardiac ischemic events at follow-up; a lower left ventricular ejection fraction was associated with mortality; higher peak troponin I and previous PCI were associated with cardiac ischemic events at follow-up. At multivariate analysis longer hospital stay, higher discharge creatinine levels, and previous PCI were independent predictors of cardiac ischemic events at follow-up. Our evaluation in ACS patients treated with an early invasive strategy does not support the concept that angiography should be performed as soon as possible after symptom onset or hospital admission. Rather, an unfavorable long-term outcome is influenced principally by the clinical complexity of patients.

Prognostic value of creatine kinase-myocardial band isoenzyme elevation following percutaneous coronary intervention: a meta-analysis

OBJECTIVES

To assess whether different degrees of creatine kinase-myocardial band isoenzyme (CK-MB) elevation after percutaneous coronary intervention (PCI) affect the subsequent risk of death.

BACKGROUND

While there is consensus that extensive cardiac enzyme elevation increase mortality significantly, there is uncertainty about the exact clinical impact of smaller CK-MB elevations after PCI.

METHODS

The published literature was scanned by formal searches of electronic databases such as PubMed and MEDLINE from January 1999 to October 2011. Risk ratio (RR) was used as summary estimate.

RESULTS

Ten studies have been included totaling 48,022 patients who underwent PCI (12,246 patients with CK-MB elevation and 35,776 patients without CK-MB elevation). Mean followup duration for each study ranged from 6 to 48 months. CK-MB elevation >1× the upper limit of normal (ULN) conferred a significant increase in the risk of mortality with an overall RR of 1.74 (95% confidence interval [CI], 1.42 to 2.13, P < 0.001). Compared with patients without CK-MB elevation, there was a dose-response relationship with RR for death being 1.48 (95% CI, 1.25-1.77, P < 0.001) with CK-MB elevation 1 to <3× ULN, 1.71 (95% CI, 1.23-2.37, P = 0.001) with CK-MB elevation 3 to 5× ULN, and 2.83 (95% CI, 1.98-4.04, P < 0.001) with CK-MB elevation ≥ 5× ULN.

CONCLUSIONS

Even a small increase in CK-MB levels after PCI is associated with significantly higher risk of late mortality. Monitoring cardiac enzymes after PCI may help predict the long term clinical outcome.

With the "universal definition," measurement of creatine kinase-myocardial band rather than troponin allows more accurate diagnosis of periprocedural necrosis and infarction after coronary intervention

OBJECTIVES

We aimed to assess the differential implications of creatine kinase-myocardial band (CK-MB) and troponin measurement with the universal definition of periprocedural injury after percutaneous coronary intervention.

BACKGROUND

Differentiation between definitions of periprocedural necrosis and periprocedural infarction has practical, sociological, and research implications. Troponin is the recommended biomarker, but there has been debate about the recommended diagnostic thresholds.

METHODS

Thirty-two patients undergoing multivessel percutaneous coronary intervention and late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging in a prospective study had cardiac troponin I, CK-MB, and inflammatory markers (C-reactive protein, serum amyloid A, myeloperoxidase, tumor necrosis factor alpha) measured at baseline, 1 h, 6 h, 12 h, and 24 h after the procedure. Three "periprocedural injury" groups were defined with the universal definition: G1: no injury (biomarker <99th percentile); G2: periprocedural necrosis (1 to 3 × 99th percentile); G3: myocardial infarction (MI) type 4a (>3 × 99th percentile). Differences in inflammatory profiles were analyzed.

RESULTS

With CK-MB there were 17, 10, and 5 patients in groups 1, 2, and 3, respectively. Patients with CK-MB-defined MI type 4a closely approximated patients with new CMR-LGE injury. Groups defined with CK-MB showed progressively increasing percentage change in C-reactive protein and serum amyloid A, reflecting increasing inflammatory response (p < 0.05). Using cardiac troponin I resulted in 26 patients defined as MI type 4a, but only a small minority had evidence of abnormality on CMR-LGE, and only 3 patients were defined as necrosis. No differences in inflammatory response were evident when groups were defined with troponin.

CONCLUSIONS

Measuring CK-MB is more clinically relevant for diagnosing MI type 4a, when applying the universal definition. Current troponin thresholds are oversensitive with the arbitrary limit of 3 × 99th percentile failing to discriminate between periprocedural necrosis and MI type 4a. (Myocardial Injury following Coronary Artery bypass Surgery versus Angioplasty: a randomised controlled trial using biochemical markers and cardiovascular magnetic resonance imaging; ISRCTN25699844).

Prognostic value of cardiac troponin-I or troponin-T elevation following nonemergent percutaneous coronary intervention: a meta-analysis

OBJECTIVES

The aim of this meta-analysis was to assess the prevalence and prognostic value regarding mortality of cTnT or cTnI elevations after nonemergent percutaneous coronary intervention (PCI) in a large number of cohort/registry studies.

BACKGROUND

Routine cardiac troponin measurement after elective PCI has been controversial among interventionalists. Recent studies have provided conflicting data in regard to predictive value of cardiac troponin-T (cTnT) and troponin-I (cTnI) elevation after non-emergent PCI.

METHODS

Electronic and manual searches were conducted of all published studies reporting on the prognostic impact of cTnT or cTnI elevation after elective PCI. A meta-analysis was performed with all-cause mortality at follow-up as the primary endpoint.

RESULTS

We identified 22 studies, involving 22,353 patients, published between 1998 and 2009. Postprocedural cTnT and cTnI were elevated in 25.9% and 34.3% of patients, respectively. Follow-up period ranged from 3 to 67 months (mean: 17.7 ± 14.9 months). The results showed no heterogeneity among the trials (Q-test: 25.39; I(2) : 17%; P = 0.23). No publication bias was detected (Egger's test: P = 0.16). The long-term all-cause mortality in patients with cTnI or cTnT elevation after PCI (5.8%) was significantly higher when compared to patients without cTnI or cTnT elevation (4.4%); OR 1.45 (95% CI: 1.22-1.72), P < 0.01. In addition, the postprocedural composite adverse clinical events of all-cause mortality or myocardial infarction (MI) in patients with cTnI or cTnT elevation after PCI (9.2%) was significantly higher when compared to patients without cTnI or cTnT elevation (5.3%); OR 1.77 (95% CI: 1.48-2.11), P < 0.01.

CONCLUSIONS

The current meta-analysis indicates that cTnI or cTnT elevation after nonemergent PCI is indicative of an increase in long-term all-cause mortality as well as the composite adverse events of all-cause mortality and MI. Efforts to routinely monitor periprocedural cTn levels along with more intensive outpatient monitoring/treatment of patients with cTn elevations may help to improve the long-term adverse outcomes in these patients following non-emergent PCI.

Periprocedural myocardial infarction: review and classification

Technical and pharmacologic advances have reduced the occurrence of large periprocedural myocardial infarction (PMI) after percutaneous coronary interventions (PCI), but PMI still occurs in 6% to 18% of the cases and is associated with impaired short- and long-term survival. PMI might be due to side branch closure or flow-limiting dissection, but is most often diagnosed after apparently uncomplicated PCI and is due to atheroembolization into the microcirculation. Various definitions of PMI are used in clinical trials, but a rise in creatine kinase-MB greater than 3 to 8 times the upper limit of normal is consistently associated with worse prognosis, particularly as it reflects a more extensive and unstable atherosclerotic burden. On the other hand, data regarding the independent prognostic value of periprocedural troponin increase are conflicting. Some data suggest that PMI has a better prognosis than a spontaneously occurring myocardial infarction, and that its incidence is reduced with aggressive antiplatelet and statin therapy.

Relation of troponin I levels following nonemergent percutaneous coronary intervention to short- and long-term outcomes

Increases of creatine kinase (CK) and CK-MB cardiac enzymes after nonemergent percutaneous coronary intervention (PCI) have been associated with an increased risk of cardiovascular events during follow-up. However, there are limited data about the incidence and prognostic significance of an isolated increase of cardiac troponin I (cTnI) without an increase in CK-MB after PCI. The aim of this study was to evaluate the impact of an isolated cTnI increase on long-term survival in patients undergoing nonemergent PCI with normal CK-MB levels after PCI. Using the 2004/2005 Cornell Angioplasty Registry, we evaluated the clinical outcomes in 1,601 patients (undergoing elective or urgent PCI) with normal preprocedure cTnI and CK-MB and normal CK-MB levels after the procedure. Patients were divided into 2 groups based on the presence of cTnI increase after PCI. The mean follow-up period was 24.6 +/- 7.6 months. An increase in cTnI was observed in 831 patients (51.9%). Drug-eluting stents were used in 87% of patients and glycoprotein IIb/IIIa inhibitors were administered in 48% of patients. Incidence of in-hospital major adverse cardiovascular events was low, 0.1% versus 0% (p = 1.000), in patients with versus without cTnI increases, respectively. By 2 years of follow-up, Kaplan-Meier survival rates were 94.1% versus 96.4% (log-rank p = 0.020) in those with versus without cTnI increases, respectively. By multivariate Cox regression analysis, an increase in cTnI after PCI (hazard ratio 1.62, 95% confidence interval 1.01 to 2.59, p = 0.047) was an independent predictor of increased long-term mortality. In conclusion, an isolated increase in cTnI after nonemergent PCI is common, not associated with more frequent adverse in-hospital outcomes compared to patients with normal cTnI, and provides long-term prognostic information regarding mortality.

Troponin must be measured before and after PCI to diagnose procedure-related myocardial injury

OBJECTIVE

To evaluate troponin I >99th percentile of normal as a criterion for myocardial injury after percutaneous coronary intervention (PCI).

DESIGN

Troponin I and creatine kinase monobasic (CK-MB) were measured in 327 patients before and after percutaneous transluminal coronary angioplasty (PTCA) with stent implantation.

RESULTS

Troponin I was elevated before PCI in 100 of a total of 222 patients with acute coronary syndrome (ACS). In 91 of these 100 patients, troponin I was elevated also after PCI but actual increases in troponin I concentrations from before to after PCI were found in only 32 patients. The increase of troponin I correlated with post-procedural CK-MB whereas post-procedural troponin I levels did not correlate. In the 122 patients with ACS but normal/normalized troponin I before PCI and in 105 patients with stable coronary artery disease post-procedural troponin I appeared to be a reliable indicator of myocardial infarction (MI), however more sensitive than CK-MB.

CONCLUSION

Troponin I after PCI is sensitive to pre-procedural concentrations. To avoid false positive MI diagnoses we thus suggest that troponin I should be measured before as well as after the procedures and only actual increases should be regarded as indicating procedure-related MI.

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.

Myocardial infarction after percutaneous coronary intervention: a meta-analysis of troponin elevation applying the new universal definition

AIM

Elevation of Troponin after scheduled percutaneous coronary intervention (PCI) is a recognized consequence. We sought to evaluate the prognostic significance and impact of the newly published definition of PCI-related myocardial infarction (MI) according to which any troponin elevation >3 times the upper reference limit identify a peri-procedural MI.

METHODS

Search of BioMedCentral, CENTRAL, mRCT and PubMed (updated May 2008). Outcomes of interest were: MACE [the composite of all cause death, MI, repeat target vessel PCI (re-PCI) and coronary artery bypass grafting (CABG)]; single end points were also assessed.

RESULTS

Fifteen studies have been included totalling 7578 patients. Troponin elevation occurred in 28.7% of the procedures. The incidence of PCI-related MI according to the new definition was 14.5%. During the hospitalization, any level of raised troponin was associated with an increased risk of MACE [OR 11.29 (3.00-42.48), Number needed to harm (NNH) 5], death [OR 7.16 (1.95-26.27), NNH = 100], MI [OR 30.85 (6.05-157.38), NNH = 4] and re-PCI [OR 4.13 (1.23-13.88), NNH = 50]. Patients with PCI-related MI had an increased risk of death [OR 17.25 (2.71-109.96), NNH = 100] and re-PCI [OR 10.86 (3.2-36.94), NNH = 25]. At follow up of 18 months any troponin elevation was associated with an increased risk of MACE [OR 1.48 (1.12-1.96), NNH = 20], death [OR 2.19 (1.59-3.00), NNH = 50], MI [OR 3.29 (2.71-6.31), NNH = 33] and re-PCI [OR 1.47 (1.06-2.03), NNH = 25]. In patients with PCI-related MI the risk of MACE was further increased: OR 2.25 (1.26-4.00), NNH = 3. An increase of the troponin level below the cut-off was not associated with MACE.

CONCLUSION

A diagnosis of MI according to the new guidelines applies to 15% of patients undergoing PCI and these patients are at high risk of further adverse events both during the hospital stay and at 18 months.

Prognostic significance of small troponin I rise after a successful elective percutaneous coronary intervention of a native artery

Cardiac troponin I is a sensitive marker of myonecrosis. Data regarding the prognostic value of troponin I increase after percutaneous coronary intervention (PCI) are conflicting. A recent American College of Cardiology/American Heart Association statement defined a troponin I increase >3 times the 99th percentile as periprocedural myocardial infarction (MI). We sought to evaluate whether or not, in patients with a successful elective PCI judged on angiographic and clinical criteria, the postprocedural increase of troponin I could predict 1-year outcomes. A cohort of 3,200 consecutive patients with successful elective PCI was studied. End points included death/MI and major adverse cardiac events at 1 year. A troponin I increase >97.5th percentile was observed in 1,402 patients (43.8%, mean 0.32 ng/ml, range 0.01 to 4.94). A total of 751 patients (23.4%) had a troponin I increase >3 x 99th percentile. Troponin I status was associated with more complex coronary disease (19.6% vs 16.4%, p <0.005) and multivessel PCI (2.1 vs 1.6, p <0.001). At 1 year, there was no difference in death/MI (2.8% vs 3.5%, p = 0.3) or in major adverse cardiac events (9.6% vs 10.4%, p = 0.5) according to the level of troponin I increase. The lack of association between troponin I increase after PCI and outcome was found when troponin I increase was used as a continuous or a categorical variable. Logistic regression models failed to find any threshold from which troponin I increase could affect outcome. In conclusion, a small troponin I increase after a successful elective PCI was not infrequent and did not affect outcome in our study. The definition of periprocedural MI may be too strict. Measurement of troponin I after a successful PCI is questionable.

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.

Prognostic importance of troponin T and creatine kinase after elective angioplasty

BACKGROUND

The prognostic importance of elevated cardiac enzymes after elective percutaneous coronary intervention has been debated. Therefore, we performed a prospective observational study to evaluate the prognostic value of postprocedural rise of troponin T and creatine kinase.

METHODS

Troponin T (cut-off value 0.05 ng/ml) and creatine kinase (cut-off value 180 IU/l with muscle-brain fraction >4%) were measured 12 h after elective percutaneous coronary intervention in 713 consecutive patients without elevated troponin before the procedure. Primary endpoint was the combined incidence of death, myocardial infarction, stroke, repeat angiography or re-admission because of anginal symptoms during the follow-up period.

RESULTS

Troponin was elevated after the procedure in 150 patients (21%) and creatine kinase in 66 pts (9%), with a strong association between increased troponin and creatine kinase. After a mean follow-up of 10.9 months, mortality was low (1%) and not associated with increased troponin or creatine kinase. There was, however, a strong relation between postprocedural troponin and re-admission for angina (p=0.001) or myocardial infarction (p=0.001). Furthermore, troponin rise was significantly associated with an increased risk of the primary endpoint (relative risk 1.55 95% confidence interval 1.01-2.38). After multivariate analysis, troponin elevation but not increased creatine kinase was associated with an increased risk of the primary endpoint (relative risk 1.59 95% confidence interval 1.02-2.47 for troponin elevation versus 1.16 95% confidence interval 0.62-2.15 for increased creatine kinase).

CONCLUSION

Increase of troponin T after elective percutaneous coronary intervention has stronger prognostic implication when compared to increased creatine kinase.

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.

Hemodynamic significance of periprocedural myocardial injury assessed with N-terminal pro-B-type natriuretic peptide after percutaneous coronary intervention in patients with stable and unstable coronary artery disease (from the JUMBO-TIMI 26 trial)

The clinical relevance of periprocedural myocardial injury related to percutaneous coronary intervention (PCI) remains controversial. N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) is a sensitive indicator of hemodynamic stress and when increased is associated with higher mortality in patients with acute and chronic ischemic heart disease. We measured the serum level of NT-pro-BNP using the Elecsys 2010 proBNP assay at baseline, 4 to 6 hours, and 12 to 24 hours in 747 patients undergoing elective or urgent PCI and enrolled in the JUMBO-TIMI 26 trial. Periprocedural myocardial infarction (MI) was independently adjudicated and required a new increase in creatine kinase-MB >3 times the upper limit of normal distinct from MI as the indication for PCI. Patients with procedural MI had significantly higher levels of NT-pro-BNP at 12 to 24 hours (405 vs 146 pg/ml, p <0.001). Moreover, the greater increase in NT-pro-BNP in patients with periprocedural MI was independent of each clinical and other procedural correlates of NT-pro-BNP after PCI (p <0.001). In addition, the magnitude of increase in NT-pro-BNP correlated strongly with extent of myocardial injury, including in patients with evidence of injury (creatine kinase-MB 1 to 3 times upper limit of normal) not meeting criteria for MI (p = 0.001) or low-level increase in troponin T (p = 0.001). In conclusion, periprocedural myocardial injury, even at low levels, during PCI is associated with increased hemodynamic stress as measured by increasing NT-pro-BNP. This finding supports the physiologic relevance of procedural MI and the continued effort to define therapies that decrease the risk of this complication.

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.

La troponine et les autres marqueurs de souffrance myocardique, quelle signification en médecine interne ?

PURPOSE

Troponin is now the gold standard for the diagnosis of myocardial infarction. Aiming at improving the management of a patient suspect of an acute coronary syndrome, this article will point the interpretation of troponin dosages according to the clinical presentation and concomitant diseases.

ACTUALITIES

First, the interest of troponin dosage as compared with other markers of myocardial ischemia will be underlined. Then, the literature available about troponin in cardiovascular diseases but also in extracardiac diseases will be analysed. Finally, the difficulties of assay will be discussed.

PERSPECTIVES

The availability of a sensitive and specific marker such as troponin is definitively a progress in the management of patients with an acute coronary syndromes. But it remains a biological contribution to the global management of the patient. It is important to know the causes susceptible to increase the levels of troponin to avoid a wrong interpretation of the dosage, leading to diagnostic but also therapeutic mistakes.

Baseline troponin level: key to understanding the importance of post-PCI troponin elevations

AIMS

The adverse prognostic significance of biomarker elevations after percutaneous coronary intervention (PCI) is well established. However, often baseline troponin values are not included in the analysis or sensitive criteria are not employed. Accordingly, we assessed the timing and magnitude of post-PCI troponin T (cTnT) levels and their relationships to outcomes in patients with and without pre-PCI baseline cTnT elevations using a sensitive assay and sensitive cut-off values.

METHODS AND RESULTS

cTnT was measured at baseline (pre-PCI), 8 and 16 h post-PCI in 2352 patients. A cTnT elevation was defined as > or =0.03 ng/mL. No baseline cTnT elevations were detected in 1619 patients undergoing mostly (97%) non-urgent procedures (cTnT = 0.01 +/- 0.002 ng/mL; mean +/- SD). 733 patients had baseline cTnT elevations. Only the baseline troponin value had prognostic importance. Patients with elevated cTnT baseline levels had a higher overall cumulative 12-month death/MI rate of 11.1% compared with those without elevated baseline levels of 4.7% (P < 0.05). Neither the timing nor the magnitude of the post-procedure cTnT elevations was predictive of long-term death/MI rates when baseline elevations were included in the analysis. Similar findings were observed for baseline creatine kinase-MB (CK-MB) levels. Late increases in cTnT levels (16 h post-PCI) presaged in-hospital events only.

CONCLUSION

Long-term prognosis is most often related to the baseline pre-PCI troponin value and not the biomarker response to the PCI. These results support a re-evaluation of the use of biomarker data in relation to PCI.

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.

Percutaneous coronary intervention: recommendations for good practice and training

Cardiologists undertaking percutaneous coronary intervention (PCI) are excited by the combination of patient and physician satisfaction and technological advance occurring on the background of the necessary manual dexterity. Progress and applicability of percutaneous techniques since their inception in 1977 have been remarkable; a sound evidence base coupled with the enthusiasm and ingenuity of the medical device industry has resulted in a sea change in the treatment of coronary heart disease (CHD), which continues to evolve at breakneck speed. This is the third set of guidelines produced by the British Cardiovascular Intervention Society and the British Cardiac Society. Following the last set of guidelines published in 2000, we have seen PCI activity in the UK increase from 33,652 to 62,780 (87% in four years) such that the PCI to coronary artery bypass grafting ratio has increased to 2.5:1. The impact of drug eluting stents has been profound, and the Department of Health is investigating the feasibility of primary PCI for acute myocardial infarction. Nevertheless, the changes in the structure of National Health Service funding are likely to focus our attention on cost effective treatments and will require physician engagement and sensitive handling if we are to continue the rapid and appropriate growth in our chosen field. It is important with this burgeoning development now occurring on a broad front (in both regional centres and district general hospitals) that we maintain our vigilance on audit and outcome measures so that standards are maintained for both operators and institutions alike. This set of guidelines includes new sections on training, informed consent, and a core evidence base, which we hope you will find useful and informative.

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

AIMS

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

METHODS AND RESULTS

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

CONCLUSION

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

Effect of glucose-insulin-potassium infusion on myocardial damage due to percutaneous coronary revascularization

Percutaneous coronary intervention has been known to cause myocardial damage as a result of microvascular dysfunction due to microembolization and microinfarction. Previous studies have shown that glucose-insulin-potassium (GIK) infusion decreases mortality in patients with acute myocardial infarction. Therefore, in this study, we aimed to investigate the effect of GIK infusion on myocardial damage due to percutaneous coronary revascularization. A total of 52 consecutive nondiabetic patients diagnosed with non-ST-elevation acute coronary syndrome and designated for elective percutaneous coronary intervention were randomized in a double-blind fashion into GIK and normal saline groups. GIK infusion (30% dextrose, 300 U insulin, and 60 mEq potassium chloride) at a dose of 1.5 ml/kg/hour was initiated 24 hours before the intervention and continuing during and until 1 hour after the intervention. Troponin I levels were recorded in venous blood samples before and 12 and 24 hours after the intervention. The increase in troponin I was significantly lower at 12 and 24 hours in the GIK group compared with those of the saline controls (p=0.022 and p=0.005, respectively). GIK infusion initiated 24 hours before coronary stenting for non-ST-elevation acute coronary syndrome resulted in less myocardial damage as determined by postprocedure troponin I levels.

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.

Association of Mild Transient Elevation of Troponin I Levels With Increased Mortality and Major Cardiovascular Events in the General Patient Population

Context.—The prognostic value of mild elevation of cardiac-specific troponin I (cTnI) levels is poorly defined, which can make interpretation of such an elevation difficult.

Objective.—To study the prognostic value of transient mild elevation of cTnI levels in the hospitalized patient population.

Design.—We performed a case-control study that compared the outcome of patients hospitalized for any cause with at least 2 subsequent transient cTnI measurements of 0.1 ng/mL or higher and less than 1.5 ng/mL with matched controls with cTnI levels less than 0.1 ng/mL. A cohort of 118 patients (mean ± SD age, 67.4 ± 14.0 years; 35.6% men) was followed up for an average ± SD of 11.9 ± 7.9 months. Seventy-one cases were matched with 37 controls in terms of demographics, coronary artery disease risk factors, and reason for admission. End points were all-cause mortality and major cardiovascular end points, including cardiovascular mortality, myocardial infarction, and revascularization.

Results.—The total event rate was significantly increased in the case group compared with the control group at 12, 6, and 3 months (62.0% vs 24.3%, 59.2% vs 16.2%, and 47.9% vs 5.4%, respectively; P &lt; .001). At 12, 6, and 3 months, the cases had a significant increase in all-cause mortality (43.7% vs 16.2%, 40.8% vs 8.1%, and 33.8% vs 0.0%, respectively; P = .005) and major cardiovascular end points (26.8% vs 8.1%, 26.8% vs 8.1%, and 21.1% vs 5.4%, respectively; P = .02) compared with controls.

Conclusion.—Transient mild elevation of cTnI levels in hospitalized patients is associated with an increase in all-cause mortality and major cardiovascular complications. Such elevations of cTnI levels can be considered a marker for both all-cause and cardiovascular morbidity and mortality.

Relationship of Serum Cardiac Markers following Successful Percutaneous Coronary Intervention and Subsequent Exercise Capacity in Patients with Chronic Stable Angina: A Pilot Study

We performed a pilot study to assess the significance of modest, asymptomatic, elevated serum cardiac markers--troponin T (TnT) and creatinine kinase-MB (CK-MB)--18-24 h following successful elective percutaneous coronary intervention (PCI) and to explore their relationship with changes in aerobic exercise capacity, as measured by peak oxygen consumption (VO2), 6 weeks following the procedure. Twenty-three patients with single-vessel disease and chronic angina performed an incremental cardiopulmonary exercise test before and 6 weeks after successful uncomplicated PCI. A venous blood sample was taken at rest before PCI and 18-24 h after the procedure. Successful PCI resulted in a trend towards an increased peak VO2 [21.62 +/- 0.64 (pre) vs. 23.03 +/- 0.75 ml/ kg/min (post), p = 0.07; mean +/- SEM]. There was a significant increase [median (IQR)] in TnT, from 0.00 (0.00) microg/l at baseline increasing to 0.02 (0.03) microg/l at 18-24 h, p = 0.002. CK-MB levels showed no significant difference. In the group of 15/23 (65%) patients with an elevation in serum TnT (>/=0.01 microg/l), 18-24 h after successful PCI, there was no significant increase in peak VO2 [23.31 +/- 0.96 (pre) vs. 23.89 +/- 1.09 ml/kg/min (post), p = 0.57]. In 8 (35%) patients with no rise in TnT at 18-24 h, a significant increase in peak VO2 was observed following successful PCI [23.10 +/- 0.91 (pre) vs. 25.09 +/- 0.75 ml/kg/min (post), p = 0.02]. Although 7 of these 8 patients increased their peak VO2, the absence of a TnT rise at 18-24 h was not significantly associated with an increase in peak VO2 following successful PCI (p = 0.18). To confirm these interesting initial results and investigate the relationship of serum cardiac markers following successful PCI and subsequent exercise capacity, further studies are required.

Predictors and prognostic value of myocardial injury following stent implantation

BACKGROUND

Troponin I concentrations are frequently elevated following percutaneous coronary intervention (PCI) even in procedures without complications and are considered, by some, as predictive of long-term morbidity and mortality. We assessed whether post-PCI troponin I concentrations bore any relationship to clinical, angiographic and in-laboratory minor adverse events indicative of myocardial injury and evaluated, in follow-up, whether these levels are useful as a predictive markers of adverse events.

METHODS

Patients (n=147) who were scheduled for PCI for stent placement were prospectively studied. In-laboratory events recorded were protracted chest pain, electrocardiographic changes, slow flows, dissections and lateral branch affectation. Troponin I and creatinine kinase MB fraction (CK-MB) mass were measured at baseline and post-procedure. Mean clinical follow-up was for 10.4+/-3.6 months.

RESULTS

During PCI, at least one adverse event occurred in 34% of patients and, in 38% of them, there was an elevation of troponin I as compared to 5.1% of those patients without any adverse event (relative risk=7.4; P<0.001). Elevation of troponin I concentrations occurred in 16.3% of all patients, 79.2% associated with an AE. CK-MB was elevated in 15.6% of patients. On multivariate analysis, protracted chest pain, lateral branch involvement and slow flow remained statistically significant in relation to post-procedure elevations of troponin I concentrations. Clinical follow-up showed a poorer prognosis in patients who had had elevated troponin I concentrations.

CONCLUSIONS

In-laboratory adverse event predict elevated post-procedure troponin I concentrations which are associated with myocardial injury. These elevations, in turn, predict poorer medium-term clinical outcomes.