Prognostic implication of troponin I elevation after percutaneous coronary intervention

Predictors and clinical significance of periprocedural myocardial infarction following rotational atherectomy

OBJECTIVES

To investigate the potential predictors and clinical significance of periprocedural myocardial infarction (PMI), as defined by the latest Fourth Universal Definition of Myocardial Infarction (2018), following rotational atherectomy (RA).

BACKGROUND

PMI is not uncommon in patients undergoing RA, although the predictors and prognostic impact are unknown.

METHODS

Data from 229 consecutive patients who had undergone RA before drug-eluting stent (DES) implantation in a single center were analyzed. Patients' demographic information, clinical, angiographic, and procedural characteristics, and 1-year follow-up outcomes were collected retrospectively.

RESULTS

The overall incidence of PMI in patients undergoing RA was 48.5%. Age (adjusted odds ratio [OR]: 1.024, 95% confidence interval [CI]: 1.001-1.047, p = 0.043) and ejection fraction (adjusted OR: 0.977, 95% CI: 0.962-0.993, p = 0.004) were independent predictors of PMI in RA, although PMI was not associated with an increased risk of major adverse cardiovascular and cerebrovascular events (MACCEs) at the 1-year follow-up in patients undergoing RA.

CONCLUSION

Age and ejection fraction were independently associated with an elevated risk of PMI in patients undergoing RA. However, post-RA microinfarcts were not associated with an increased risk of MACCEs over the short-term follow-up period.

Clinical Outcomes and Angiographic Results of Bailout Stenting for Guide Catheter-Induced Iatrogenic Coronary Artery Dissection - Impact of Stent Type

BACKGROUND

Guide catheter-induced iatrogenic coronary artery dissection is a rare but feared complication. When it occurs, bailout stenting is widely performed; however, its prognosis and the impact of stent type remains unclear.Methods and Results:The study population consisted of 77,257 consecutive patients (coronary angiography, 55,864; percutaneous coronary intervention, 21,393) between 2000 and 2015. We investigated the incidence, clinical outcomes, and angiographic results after bailout stenting and compared by stent type: bare-metal stent (BMS) and drug-eluting stent (DES). Iatrogenic coronary artery dissection occurred in 105 patients (incidence rate, 0.14%). All cases of iatrogenic coronary artery dissection that were recognized as requiring bailout procedure could be managed by stent implantation, and no patients died during bailout procedure. The 5-year cumulative incidences of cardiac death, target lesion revascularization, and major adverse cardiac events were 11.3%, 10.3%, and 21.0%, respectively. The binary restenosis rate was 10.4%, and it was not significantly different between BMS and DES implantation. In lesions with preprocedural stenosis, however, it was significantly lower in the DES group than in the BMS group. On the other hand, coronary artery dissection recurred in 8 patients, which was observed only after DES implantation.

CONCLUSIONS

The immediate and long-term outcomes of bailout stenting for iatrogenic coronary artery dissection were acceptable. Although DES may be favorable for stenotic lesions, coronary artery dissection can recur after DES implantation.

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.

Prognostic and Practical Validation of Current Definitions of Myocardial Infarction Associated With Percutaneous Coronary Intervention

OBJECTIVES

In 13,038 patients with non-ST-segment elevation acute coronary syndrome undergoing index percutaneous coronary intervention (PCI) in the EARLY ACS (Early Glycoprotein IIb/IIIa Inhibition in Non-ST-Segment Elevation Acute Coronary Syndrome) and TRACER (Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome) trials, the relationship between PCI-related myocardial infarction (MI) and 1-year mortality was assessed.

BACKGROUND

The definition of PCI-related MI is controversial. The third universal definition of PCI-related MI requires cardiac troponin >5 times the 99th percentile of the normal reference limit from a stable or falling baseline and PCI-related clinical or angiographic complications. The definition from the Society for Cardiovascular Angiography and Interventions (SCAI) requires creatine kinase-MB elevation >10 times the upper limit of normal (or 5 times if new electrocardiographic Q waves are present). Implications of these definitions on prognosis, prevalence, and implementation are not established.

METHODS

In our cohort of patients undergoing PCI, PCI-related MIs were classified using the third universal type 4a MI definition and SCAI criteria. In the subgroup of patients included in the angiographic core laboratory (ACL) substudy of EARLY ACS (n = 1,401) local investigator- versus ACL-reported angiographic complications were compared.

RESULTS

Altogether, 2.0% of patients met third universal definition of PCI-related MI criteria, and 1.2% met SCAI criteria. One-year mortality was 3.3% with the third universal definition (hazard ratio: 1.96; 95% confidence interval: 1.24 to 3.10) and 5.3% with SCAI criteria (hazard ratio: 2.79; 95% confidence interval: 1.69 to 4.58; p < 0.001). Agreement between ACL and local investigators in detecting angiographic complications during PCI was overall moderate (κ = 0.53).

CONCLUSIONS

The third universal definition of MI and the SCAI definition were both associated with significant risk for mortality at 1 year. Suboptimal concordance was observed between ACL and local investigators in identifying patients with PCI complications detected on angiography. (Trial to Assess the Effects of Vorapaxar [SCH 530348; MK-5348] in Preventing Heart Attack and Stroke in Participants With Acute Coronary Syndrome [TRA·CER] [Study P04736]; NCT00527943; EARLY ACS: Early Glycoprotein IIb/IIIa Inhibition in Patients With Non-ST-Segment Elevation Acute Coronary Syndrome [Study P03684AM2]; NCT00089895).

Predictive value of plaque morphology assessed by frequency-domain optical coherence tomography for impaired microvascular perfusion after elective stent implantation: the intracoronary electrocardiogram study

Aims

This study was undertaken to assess the association between plaque features at culprit lesions assessed by frequency-domain optical coherence tomography (FD-OCT) and impaired microvascular perfusion estimated by intracoronary electrocardiogram (IcECG) after elective percutaneous coronary intervention (PCI). Furthermore, we investigated whether IcECG could predict future cardiac events.

Methods and results

This study consisted of 84 patients who underwent both FD-OCT and IcECG during PCI. Patients were classified into two groups based on ST-segment elevation (ST-E) on IcECG after the procedure; ST-E (-) group (n = 53) and ST-E (+) group (n = 31). Minimum fibrous cap thickness was significantly thinner in the ST-E (+) group than in the ST-E (-) group (240 μm [IQR 180 to 310] vs. 100 μm [IQR 60 to 120], P < 0.001). Plaque rupture (7.5% vs. 35.5%, P = 0.001), lipid-rich plaque (75.5% vs. 100%, P < 0.001), the thin cap fibroatheroma (0% vs. 25.8%, P < 0.001) on pre-FD-OCT, protrusion (18.9% vs. 56.7%, P < 0.001), and intra-stent dissection (15.1% vs. 50.0%, P < 0.001) on post-FD-OCT were significantly more frequently found in the ST-E (+) group than in the ST-E (-) group. The incidence of MACE (cardiac death, myocardial infarction, revascularization, hospitalization for heart failure) during 1-year was significantly higher in the ST-E (+) group than in the ST-E (-) group (5.7% vs. 19.4%, P < 0.05).

Conclusion

Plaque features assessed by FD-OCT might be associated with impaired microvascular perfusion and ST-segment elevation on IcECG after the procedure could predict 1-year cardiac events after elective PCI.

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.

Heart-type fatty acid-binding protein (H-FABP) and highly sensitive troponin T (hsTnT) as markers of myocardial injury and cardiovascular events in elective percutaneous coronary intervention (PCI)

BACKGROUND/INTRODUCTION

Type 4a myocardial infarction (MI) occurs when myocardial injury is combined with either symptoms suggestive of myocardial ischaemia, new left bundle branch block, angiographic loss of patency of a major artery or imaging suggestive of new loss of myocardium. Myocardial injury is defined as a rise of >5 x 99th upper reference limit (URL) of 14 ng/l (i.e. >70 ng/l) for highly sensitive troponin T (hsTnT) at 6 h if hsTnT was normal at baseline or >20% rise from 0 to 6 h if hsTnT was >14 ng/l at baseline.

AIM

To assess the prognostic value of biomarkers of myocardial injury following elective percutaneous coronary intervention (PCI).

DESIGN

A cohort of 209 patients were included of whom 144 (68.9%) were male, mean age was 68.8 years, 28 (13.4%) were smokers, 31 (14.8%) were diabetic, 199 (95.2%) had hypercholesterolaemia and 138 (66.0%) had hypertension.

METHODS

We evaluated hsTnT, heart-type fatty acid-binding protein (H-FABP), troponin I (TnI), creatine kinase MB type (CKMB), myoglobin, glycogen phosphorylase BB (GPBB) and carbonic anhydrase III (CA III) at 0, 4, 6 and 24 h following elective PCI. Patients were followed up at 1 year to assess for major adverse clinical events (MACE).

RESULTS

Myocardial injury was observed in 37 (17.7%) patients. Median hsTnT/H-FABP at 4 h were most predictive. MACE was noted in 6 (2.9%) patients, 3 had type 4a MI post PCI, P = 0.036.

DISCUSSION/CONCLUSIONS

Median 4 h hsTnT/H-FABP were most predictive of myocardial injury following PCI. H-FABP and hsTnT were predictive of MACE.

Impact of coronary plaque morphology assessed by optical coherence tomography on cardiac troponin elevation in patients with non-ST segment elevation acute coronary syndrome

OBJECTIVES

This study aimed to use optical coherence tomography (OCT) to study the relationship between plaque morphology prior to percutaneous coronary intervention (PCI) and post-PCI cardiac troponin (cTn) elevations in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS). Furthermore, the relationship between these findings and the adverse cardiac events during follow-up was assessed.

BACKGROUND

Association between post-PCI cTn elevations and OCT findings in NSTE-ACS patients is unclear.

METHODS

We evaluated 167 patients with stable or falling cTn values after admission who underwent PCI. Periprocedural myocardial injury (PMI) was defined as an cTn increase of more than 70× upper limit of normal (ULN) in troponin-negative patients before PCI, or more than new 70× ULN elevation from the previous nadir level in pre-PCI troponin-positive patients. Clinical and OCT findings were compared between patients with (n = 48, 29%) and without (n = 119, 71%) PMI.

RESULTS

PMI was associated with age, prior PCI, low estimated glomerular filtration rate (eGFR), OCT-derived thin-cap fibroatheroma (TCFA), plaque rupture, and lipid length. In multivariable analysis, TCFA (odds ratio [OR], 2.88; P = 0.011), eGFR (OR, 0.97, P = 0.003), and lipid length (OR, 1.12, P = 0.020) were independent predictors of PMI. At a median follow-up of 38 months, event-free survival was significantly worse in patients with PMI (log-rank test χ²  = 6.47, P = 0.011).

CONCLUSIONS

OCT analysis showed that PMI occurs more frequently in lesions with TCFA in NSTE-ACS patients, and may identify patients having a higher risk of adverse cardiac events during follow-up. © 2017 Wiley Periodicals, Inc.

Consensus or Controversy?: Evolution of Criteria for Myocardial Infarction After Percutaneous Coronary Intervention

BACKGROUND

The definition and the clinical implications of myocardial infarction (MI) occurring in the setting of percutaneous coronary intervention have been subjects of unresolved controversy. As a result of the use of more sensitive diagnostic tools such as cardiac troponin, the expanding evidence, and the ensuing debate, the definition of procedural MI (pMI) has evolved, leading to several revisions, different proposed definitions, and lack of standardization in randomized clinical trials.

CONTENT

In this review, we will describe the key clinical data on cardiac biomarkers, creatine kinase isoenzyme MB and cTn, in the setting of percutaneous coronary intervention and the main issues that have lead to various consensus documents with a proposed definition of pMI. We will focus on the rationale of the current “Third Universal Definition of Myocardial Infarction” and of the alternative approach proposed by the Society for Cardiovascular Angiography and Interventions.

SUMMARY

The definition of pMI is an evolving field where the Third Universal MI definition represents the best attempt to date to incorporate available evidence along with scientific and clinical judgment into criteria to ensure adequate specificity in the diagnosis and the relevant prognostic significance, while trying to maintain sensitivity. Questions on the recommended criteria and their practical implementation remain, but the Third Universal definition document represents an important milestone toward a better standardization and enhanced consensus on the pMI definition.

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.

The prognostic role of troponin I elevation after elective percutaneous coronary intervention

OBJECTIVES

To assess the prognostic role of isolated troponin I (TnI) elevation after elective percutaneous coronary intervention (PCI) in patients with stable coronary artery disease.

BACKGROUND

The prognostic role of minor troponin elevation after PCI is controversial.

METHODS

A total of 1532 consecutive patients who underwent elective PCI were included. Follow-up data were obtained for 1432 of 1532 (93.4%) patients. The events taken into account in the follow-up included total mortality, cardiac death, hospitalization for acute myocardial infarction and/or unstable angina.

RESULTS

The following variables were identified as predictive of major adverse cardiac events (MACE) by univariate analysis: age 75 years at least (P = 0.012), ejection fraction less than 50% (P = 0.001), prior myocardial infarction (P = 0.031) and TnI 1.0 ng/ml at least after PCI (P = 0.04). The Cox-regression model identified the TnI elevation after PCI, the older age and the ejection fraction as independent predictors of MACE during follow-up (TnI: P = 0.042; older age: P = 0.001; ejection fraction: P = 0.003). In a subgroup of patients with preserved ejection fraction, the incidence of MACE was significantly higher in those with TnI of at least 1.0 ng/ml at least than in the ones with TnI less than 1.0 ng/ml, with the highest incidence among the older cohort. The multivariate analysis confirmed the TnI elevation 1.0 ng/ml at least after PCI and the older age as predictors of MACE.

CONCLUSION

This study documented that in clinically stable patients, minor TnI elevations after elective PCI are independent predictors of MACE during follow-up, as are older age and reduced ejection fraction. Additionally, TnI elevation was a predictor of MACE during follow-up in a subset of patients with preserved ejection fraction. The combination of TnI elevation and older age confers the highest risk of MACE.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Elevation of biomarkers and long-term outcome after percutaneous coronary intervention

BACKGROUND/OBJECTIVES

The impact of an elevation of cardiac biomarkers occurring after percutaneous coronary intervention (PCI) on long-term outcome remains controversial. Most available data are based on observational registries using multivariable analysis. In this study, a case-control approach was used to assess separately the impact of post-PCI elevation of CK-MB on the short-term in-hospital outcome and on the long-term outcome after hospital discharge.

METHODS

Between 1 January 1996 and 31 December 2008, a postprocedural rise of CK-MB was observed in 363 among 8346 consecutive PCI procedures (4·3%). The overall in-hospital mortality for patients with or without CK-MB elevation after PCI was 8·5% and 1·5%, respectively (P < 0·001). For 245 hospital survivors with CK-MB elevation, we found 245 control cases matched for 9 relevant clinical parameters in our PCI database during the same period. The long-term survival of these patients was assessed by KM estimates.

RESULTS

Despite an increased in-hospital mortality among patients with periprocedural elevation of CK-MB, the long-term outcome of patients who are discharged alive is independent of CK-MB release, curves of overall survival and of survival free of recurrence of myocardial infarction being similar up to 10 years after hospital discharge.

CONCLUSIONS

In our population, the elevation of CK-MB after PCI identified a high-risk subgroup for in-hospital mortality but had no impact on the long-term prognosis, once the patient is discharged alive from the hospital.

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.

Diagnostic and prognostic value of minor elevated cardiac troponin levels for percutaneous coronary intervention-related myocardial injury: a prospective, single-center and double-blind study

Cardiac troponin-I (cTnI) and -T (cTnT) are sensitive and specific markers of myocardial injury. However, the role of increased cTnI and cTnT in percutaneous coronary intervention (PCI)-related myocardial injury remains controversial. In this prospective, single-center and double-blind study, we aimed to determine the diagnostic and prognostic value of cTnI as well as cTnT (cTns) in PCI-related myocardial injury in a Chinese population. A total of 1,008 patients with stable angina pectoris and non-ST-segment elevation acute coronary syndrome were recruited. The levels of cTnI and cTnT were examined before and after PCI. All patients were followed up for 26±9 months to observe the incidence of major adverse cardiac events (MACEs). Our results showed that post-PCI cTnI and/or cTnT levels were increased to more than the 99^th percentile upper reference limit (URL) in 133 (13.2%) patients, among which 22 (2.2%) were more than 5 × 99^th percentile URL. By univariate analysis, an elevation in cTns after PCI was not an independent predictor of increased MACEs, HR 1.35 (P  =  0.33, 95%CI: 0.74–2.46). In conclusion, our data demonstrate that the incidence of PCI-related myocardial injury is not common in a Chinese population and minor elevated cTns levels may not be a sensitive prognostic marker for MACEs.

A correlation between acute kidney injury and myonecrosis after scheduled percutaneous coronary intervention

Slight elevations in cardiac troponin I and T are frequently observed after percutaneous coronary intervention (PCI). Contrast-induced acute kidney injury (CI-AKI) is a complex syndrome induced by exposure to intravascular contrast media (CM). Currently, the relationships between the CM, pre-existing kidney insufficiency, CI-AKI, and myonecrosis after elective PCI are unclear. To investigate the relationship between CI-AKI and post-procedural myonecrosis (PMN) after PCI, we analyzed 327 non-ST-segment elevation acute coronary syndrome subjects undertaking elective PCI. The levels of cardiac troponins (cTns), cTnI and cTnT, at baseline and on at least one occasion 18-24 h after PCI were measured. We also recorded serum levels of creatinine (SCr) and the urine albumin:creatinine ratio (ACR) before coronary angiography, and 24-48 h and 48-72 h after contrast administration. A post-procedure increase in cTns was detected in 16.21% (53/327) of subjects with cTns levels >99th to 5×99th percentile upper reference limit (URL). Twenty-seven patients (8.26%) developed CI-AKI. CI-AKI occurred more often in subjects with PMN than in those without PMN (20.8% versus 5.8%, respectively, P=0.001). Multiple logistic regression analysis revealed that pre-existing microalbuminuria (MA) was an important independent predictor of PMN (OR: 3.31; 95% CI: 1.26-8.65, P=0.01). However, there was no correlation between the incidence of CI-AKI and PMN (OR: 2.38; 95% CI: 0.88-6.46, P=0.09). We conclude that pre-existing MA was not only an important independent predictor of CI-AKI but also of PMN.

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.

Is periprocedural CK-MB a better indicator of prognosis after emergency and elective percutaneous coronary intervention compared with post-procedural cardiac troponins?

A best evidence topic in interventional cardiac surgery was written according to a structured protocol. The question we addressed related to the elevation of markers of cardiac damage associated with percutaneous coronary intervention (PCI). We explored and compared the clinical and prognostic relevance of the elevation of creatinine kinase-myocardial band (CK-MB) and cardiac troponin (cTn) levels during the periprocedural period and the post-procedural period, respectively, following an emergency or elective PCI. We found in excess of 390 papers after a systematic literature search, of which 10 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. From the best evidence available it appears that the monitoring of cardiac biomarkers following a PCI can provide important clinical information about the health of the myocardium, as well as prognostic information on short to mid-term outcomes of mortality up to 3 years. The narrow evidence base advocates the use of periprocedural CK-MB monitoring, recommending that an elevation in CK-MB is a significant predictor of adverse events. Troponins remain a precise and reliable marker of cardiac damage; however, current evidence argues that cTn holds little prognostic relevance until the degree of elevation is almost five times the upper limit of normal (ULN). Thus, the best evidence recommends the use of periprocedural CK-MB routinely during PCI to provide clinical and prognostic information about the degree of myocardial injury and risk of post-procedural morbidity and mortality.

PERIPROCEDURAL MYOCARDIAL DAMAGE

Percutaneous coronary intervention (PCI), as a method of myocardial revascularisation, is widely and effectively used for the treatment of coronary heart disease (CHD), with immediate success rates of >90%. Depending on the diagnostic criteria, 5–30% of these patients could develop the signs of periprocedural myocardial damage (PMD) or periprocedural myocardial infarction (PMI). PMD predictors, mechanisms of PMD development, and its specific clinical features play an important role in the PMI prevention. At present, there is no universal agreement on the definition and diagnostics of periprocedural myocardial necrosis and PMI, or on their impact on the clinical outcomes. According to the results of the recent studies, which are presented in this review, the current criteria of PMI might need to be modified, due to the increasingly high sensitivity of the modern threshold levels of troponin. 

Risks and complications of coronary angiography: a comprehensive review

Coronary angiography and heart catheterization are invaluable tests for the detection and quantification of coronary artery disease, identification of valvular and other structural abnormalities, and measurement of hemodynamic parameters. The risks and complications associated with these procedures relate to the patient’s concomitant conditions and to the skill and judgment of the operator. In this review, we examine in detail the major complications associated with invasive cardiac procedures and provide the reader with a comprehensive bibliography for advanced reading.

Intense yellow culprit plaque coloration is closely associated with troponin-T elevation and flow complications following elective coronary stenting

AIM

The elevation of troponin-T (TnT) and occurrence of transient slow-flow phenomena have been recognized as procedure-related myocardial injuries. Little is known about the characteristics of high-risk plaque resulting in myocardial injury after coronary stenting.

METHODS

The culprit plaques in 42 consecutive patients with stable angina undergoing elective coronary stenting were observed by angioscopy. The plaque color upon angioscopic examination was classified as either intense yellow or not yellow. Slow flow was defined as < TIMI grade 3 flow during the procedure. The TnT levels were measured 8, 16, and 24 hours after stenting, and myocardial injury was defined as TnT ≥ 0.03 ng/mL at any time point.

RESULTS

Twenty-four patients (57%) had intense yellow plaques and myocardial injury occurred in 22 patients (52%). The frequency of intense yellow plaque was significantly higher in the patients with myocardial injury than in those without myocardial injury (91% vs. 20%, p < 0.001). Transient slow flow occurred frequently in patients with myocardial injury than in those without myocardial injury (23% vs. 0%, p = 0.049). All patients with transient slow flow had intense yellow plaques at the culprit lesions.

CONCLUSIONS

Intense yellow culprit plaque coloration was closely associated with TnT elevation and flow complications following elective coronary stenting. Angioscopically-observed intense yellow coloration may therefore predict high-risk plaque for peri-procedural myocardial injury.

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.

Subtle myocardial damage associated with diagnostic coronary angiography alone

AIMS

To evaluate the frequency, predictors and prognostic significance of elevation in cardiac troponin I (cTnI) after coronary angiography (CAG).

METHODS AND RESULTS

A series of 296 consecutive patients with normal pre-procedural cTnI levels and undergoing elective CAG at our centre were prospectively analysed. Positive cTnI elevation was defined as >0.06 ng/ml. Positive cTnI elevation was observed in 44 patients (14.8%), but CK-MB was elevated in only four patients (1.3%) after the procedure. The risk of cTnI elevation was independently associated with left ventricular hypertrophy (odds ratio [OR] 5.52; 95% confidence interval [CI], 2.54 to 12.02; P<0.001), inexperienced operator (OR 10.83; 95% CI, 2.47 to 47.43; P=0.002) and the amount of contrast agent (OR 1.12; 95% CI, 1.03 to 1.23; P=0.009 for each 10 ml increase), whereas it was not associated with the severity of coronary artery disease. At one year, however, postprocedural elevation of cTnI was not associated with an increased risk of death (2.3% vs. 0.8%, P=0.384) or myocardial infarction (2.3% vs. 2.0%, P=0.623).

CONCLUSIONS

A minor elevation of cTnI is observed commonly after CAG, which might be associated with left ventricular hypertrophy, operator's experience and the amount of contrast used; however, it does not influence 1-year events rates.

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.

Baseline inflammation is not predictive of periprocedural troponin elevation after elective percutaneous coronary intervention

High-sensitivity C-reactive protein predicts future cardiovascular events in both healthy individuals and patients with unstable and stable coronary syndromes. Few data are available about the incidence and the relation to inflammation of troponin elevation following percutaneous coronary intervention (PCI), a potential predictor of longterm outcome. We sought to confirm the impact of embolization on long-term outcome and evaluate the ability of baseline inflammation to predict troponin elevation induced by PCI. We prospectively analyzed 200 patients treated by PCI for stable or Braunwald IIA class unstable angina. The patients were recruited between January 1997 and May 1999, and the population was followed during a mean follow-up of 32 months. Major adverse cardiac events (MACEs) were defined as the occurrence of death, myocardial infarction or recurrent angina requiring repeat PCI, or coronary artery bypass grafting. During the follow-up period, 58 MACEs were observed. By multivariate analysis, independent predictors for the occurrence of MACEs were unstable angina and troponin I level after PCI (P < 0.0001 for both). No correlation was found between baseline inflammation and significant troponin I elevation post PCI and by multivariate analysis, no biological variable was a predictor of troponin I elevation post PCI. Baseline inflammation cannot predict onset of minor myonecrosis damage (expressed by troponin elevation) induced by PCI, a significant predictor of long-term outcome in this setting.

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.

Prognostic implications of C-reactive protein and troponin following percutaneous coronary intervention

BACKGROUND

C-reactive protein (CRP), a marker of inflammation, plays a role in the pathophysiology of atherosclerotic events. The relationship between CRP levels and myocardial necrosis assessed by troponin T (TnT) in patients undergoing percutaneous coronary intervention (PCI) has not been established. In addition, the long-term significance of TnT rise following PCI is not clear.

OBJECTIVES

To examine the relationship between CRP and the rise in TnT levels, and evaluate the long-term prognostic implications of TnT rise following PCI.

METHODS

A total of 1208 patients underwent successful nonemergent PCI. Baseline demographic characteristics, CRP and TnT levels were prospectively collected before and 12 h to 18 h following PCI. Long-term follow-up data over two years were available.

RESULTS

Among the patients studied (mean age 62 years), 64% presented with acute coronary syndrome. A PCI procedure was associated with a significant increase in TnT levels (higher than 0.1 microg/L) in 238 patients (20%). Multivariate logistic regression identified presentation with acute coronary syndrome or myocardial infarction, no statin use at the time of the procedure, increased CRP and increasing length of stent as independent predictors of TnT rise following PCI. Periprocedural TnT rise was not associated with adverse events in follow-up examinations (OR 1.09, 95% CI 0.73 to 1.65).

CONCLUSIONS

Myocardial necrosis commonly occurred in otherwise successful PCI and was particularly prevalent in the proinflammatory milieu of a recent myocardial infarction. This response was blunted with statin therapy. However, there was no long-term adverse sequelae of these troponin rises following otherwise uncomplicated PCI.

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.

Significance of Periprocedural Myonecrosis on Outcomes After Percutaneous Coronary Intervention

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

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

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

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.

Cardiac troponins in the intensive care unit: common causes of increased levels and interpretation

BACKGROUND AND OBJECTIVES

Clinical chemistry is an important component of the diagnosis of many conditions, and advances in laboratory science have brought many new diagnostic tools to the intensive care unit clinician, including new biomarkers of cardiac injury like troponin T and I. Interpretation of these clinical laboratory results requires knowledge of the performance of these tests.

SETTING AND PATIENTS

This article reviews the interpretation and performance of diagnostic markers of myocardial injury in patients with diverse clinical conditions of interest to critical care practitioners.

CONCLUSIONS

Cardiac troponin I and T, regulatory components of the contractile apparatus, are sensitive indicators of myocardial injury and have become central to the diagnosis of myocardial infarction. The troponins are also released in a number of clinical situations in which thrombotic complications of coronary artery disease and resultant acute myocardial infarction have not occurred. These situations include conditions like pulmonary embolism, sepsis, myocarditis, and acute stroke. Elevated troponins in these conditions are thought to emanate from injured myocardial cells and, in most circumstances, have been associated with adverse outcomes. Practitioners should be mindful of the wide spectrum of diseases that may result in elevated troponin when interpreting these measurements.

Markers for perioperative myocardial ischemia: what both interventional cardiologists and cardiac surgeons need to know

All novel markers of myocardial ischemia (ischemia-modified albumin, choline, unbound free fatty acids) lack cardiac specificity. Therefore, for the specific detection of myocardial ischemia selective blood sampling from an inserted coronary sinus catheter is needed, which limits the applicability of these markers in most clinical routine settings. In addition, the superiority of these novel markers over the calculation of myocardial lactate production, the current criterion standard for the laboratory diagnosis of myocardial ischemia, has not been demonstrated so far, and even comparative data is frequently lacking. Further the superiority of these new candidate markers over lactate determination for the diagnosis of myocardial ischemia in peripherally drawn blood samples has not been demonstrated either, and these novel parameters appear not to be a breakthrough for laboratory diagnosis of myocardial ischemia during or after percutaneous coronary interventions or coronary artery bypass grafting. The determination of cardiac troponin I or troponin T is the current criterion standard for the laboratory diagnosis of myocardial damage due to their higher sensitivities and specificities compared to creatine kinase isoenzyme MB. According to current knowledge, troponin increases in peripherally drawn blood samples must be regarded as an indicator of myocardial necrosis which, however, may be limited, only detectable by troponin and may be missed by creatine kinase isoenzyme MB determination. After on-pump coronary artery bypass grafting the generally applied troponin discriminator limits are not valid as there is limited, inevitable cardiac tissue damage occurring during the surgical procedure. Therefore, troponins are significantly increased after reperfusion of the arrested heart over values seen before bypass and also in patients without complications. Perioperative myocardial infarctions can be reliably identified by their characteristic troponin time courses, and both peak concentrations and time of peak values are diagnostic criteria. Troponin release is lower in off-pump compared to on-pump bypass surgery. Despite the controversy over the significance of troponin elevations after clinically uncomplicated and successful procedures, it is tempting to postulate that less myocardial damage as detected by troponin release is beneficial for the patient. After elective percutaneous coronary interventions, only troponin increases >8-fold the upper reference limit were associated with increased mortality in long-term follow-up.

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

OBJECTIVES

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.