Minor myocardial injury after elective uncomplicated successful PTCA with or without stenting: detection by cardiac troponins

Frequency of periprocedural myocardial injury and infarction stratified by cardiac troponin I and cardiac troponin T

BACKGROUND

There are different definitions of periprocedural myocardial infarction (PPMI) both in terms of thresholds for cardiac biomarkers and the ancillary criteria for myocardial ischemia. Cardiac Troponin I (cTnI) and cardiac Troponin T (cTnT) are used interchangeably to diagnose PPMI.

OBJECTIVES

This study evaluated the frequency of periprocedural myocardial injury and infarction as defined by the Society of Cardiovascular Angiography & Interventions (SCAI), the Academic Research Consortium-2 (ARC-2), and the 4th Universal definition of MI (4UDMI) stratified using cTnT versus cTnI, among patients with chronic coronary syndrome (CCS) and unstable angina.

RESULTS

Among 830 patients, PPMI rates according to the SCAI, ARC2 and 4UDMI criteria were 4.34 %, 2.05 %, and 4.94 % respectively, with higher rates seen for all definitions when using cTnI versus cTnT (SCAI: 9.84 % vs. 1.91 %, p < 0.001; ARC 2: 3.15 % vs. 1.56 %, p = 0.136; and 4UDMI 5.91 % vs. 4.51 %, p = 0.391). Minor and major periprocedural myocardial injury was respectively observed in 58.31 % and 27.10 % of patients, with rates of both significantly higher when using cTnI versus cTnT (Minor: 69.29 % vs. 53.47 %, p < 0.001, Major: 49.21 % vs. 17.36 %, p < 0.001).

CONCLUSIONS

Among patients with CCS and unstable angina, PPMIs defined by SCAI occurred more frequently when using cTnI as opposed to cTnT, whereas the type of troponin had no impact on the incidence of PPMIs according to the ARC-2 and 4UDMI.

Association between short-term exposure to ambient fine particulate matter and myocardial injury in the CATHGEN cohort

Exposure to fine particulate matter (PM_2.5) has been associated with a higher risk for coronary events. Elevated circulating cardiac troponins (cTn) are suggestive of myocardial injury in both ischemic and non-ischemic conditions. However, little is known about the association between PM_2.5 and cTn. In this study, we investigated short-term PM_2.5 effects on cardiac troponin T (cTnT), as well as N-terminal-pro brain natriuretic peptide (NT-pro BNP) and inflammatory biomarkers among cardiac catheterized participants. We analyzed 7444 plasma cTnT measurements in 2732 participants who presented to Duke University Hospital with myocardial infarction symptoms between 2001 and 2012, partly along with measurements of NT-pro BNP and inflammatory biomarkers. Daily PM_2.5 concentrations were predicted by a neural network-based hybrid model and were assigned to participants' residential addresses. We applied generalized estimating equations to assess associations of PM_2.5 with biomarker levels and the risk of a positive cTnT test (cTnT > 0.1 ng/mL). The median plasma cTnT concentration at presentation was 0.05 ng/mL and the prevalence of a positive cTnT test was 35.4%. For an interquartile range (7.6 μg/m³) increase in PM_2.5 on the previous day, cTnT concentrations increased by 7.7% (95% CI: 3.4-12.3) and the odds ratio of a positive cTnT test was 1.08 (1.01-1.16). Participants under 60 years (effect estimate: 15.2%; 95% CI: 7.4-23.5) or living in rural areas (12.3%; 95% CI: 4.8-20.3) were more susceptible. There was evidence for increases in fibrinogen and NT-pro BNP associated with elevated PM_2.5 on the concurrent and previous two days. Our study suggests that acute PM_2.5 exposure may elevate indicators of myocardial tissue damage. This finding substantiates the association of air pollution exposure with adverse cardiovascular events.

Rise of serum troponin levels following uncomplicated elective percutaneous coronary interventions in patients without clinical and procedural signs suggestive of myocardial necrosis

INTRODUCTION

The new definition of periprocedural myocardial infarction (type 4a MI) excludes patients without angina and electrocardiographic or echocardiographic changes suggestive of myocardial ischemia even though significant serum troponin elevations occur following percutaneous coronary intervention (PCI).

AIM

To evaluate the incidence and predictors of serum troponin rise following elective PCI in patients without clinical and procedural signs suggestive of myocardial necrosis by using a high-sensitivite troponin assay (hsTnT).

MATERIAL AND METHODS

Three hundred and four patients (mean age: 60.8 ±8.8 years, 204 male) undergoing elective PCI were enrolled. Patients with periprocedural angina, electrocardiographic or echocardiographic signs indicating myocardial ischemia or a visible procedural complication such as dissection or side branch occlusion were excluded. Mild-moderate periprocedural myocardial injury (PMI) and severe PMI were defined as post-PCI (12 h later) elevation of serum hsTnT concentrations to the range of 14-70 ng/l and > 70 ng/l, respectively.

RESULTS

The median pre-procedural hsTnT level was 9.7 ng/l (interquartile range: 7.1-12.2 ng/l). Serum hsTnT concentration elevated (p < 0.001) to 19.4 ng/l (IQR: 12.0-38.8 ng/l) 12 h after PCI. Mild-moderate PMI and severe PMI were detected in 49.3% and 12.2% of patients, respectively. Post-procedural hsTnT levels were significantly higher in multivessel PCI, overlapping stenting, predilatation and postdilatation subgroups. In addition, post-procedural hsTnT levels were correlated (r = 0.340; p < 0.001) with the stent lengths.

CONCLUSIONS

High-sensitivite troponin measurements indicate a high incidence of PMI even though no clinical or procedural signs suggestive of myocardial ischemia exist. Multivessel PCI, overlapping stenting, predilatation, postdilatation and longer stent length are associated with PMI following elective PCI.

Predictors and Periprocedural Myocardial Injury Rate of Small Side Branches Occlusion in Coronary Bifurcation Intervention

Occlusion of small side branch (SB) may result in significant adverse clinical events. We aim to characterize the predictors of small SB occlusion and incidence of periprocedural myocardial injury (PMI) in coronary bifurcation intervention.Nine hundred twenty-five consecutive patients with 949 bifurcation lesions (SB ≤ 2.0  mm) treated with percutaneous coronary intervention (PCI) were studied. All clinical characteristics, coronary angiography findings, PCI procedural factors, and quantitative coronary angiographic analysis data were collected. SB occlusion after main vessel (MV) stenting was defined as no blood flow or any thrombolysis in myocardial infarction (TIMI) flow grade decrease in SB after MV stenting. Multivariate logistic regression analysis was performed to identify independent predictors of small SB occlusion. Creatine kinase-myocardial band activity was determined by using an immunoinhibition assay and confirmed by mass spectrometry. Incidence of PMI between no SB occlusion group and SB occlusion group was compared.SB occlusion occurred in 86 (9.1%) of 949 bifurcation lesions. Of SB occlusion, total occlusion occurred in 64 (74.4%) lesions and a decrease in TIMI flow occurred in 22 (25.6%) lesions. True bifurcation lesion, irregular plaque, predilation in SB, preprocedural SB TIMI flow grade, preprocedural diameter stenosis of distal MV, preprocedural diameter stenosis of bifurcation core, bifurcation angle, diameter ratio between MV and SB, diameter stenosis of SB before MV stenting, and MV lesion length were independent risk factors of SB occlusion. We observed a significantly higher incidence of PMI in each cutoff level in patients with SB occlusion compared with those without SB occlusion.True bifurcation lesion, irregular plaque, and 8 other predictors were independent predictors of SB occlusion. Patients with small SB occlusion had significant higher incidence of PMI.

High levels of HB-EGF and interleukin-18 are associated with a high risk of in-stent restenosis

Objective:

To explore the clinical significance of heparin-binding epidermal growth factor-like growth factor (HB-EGF), interleukin-18 (IL-18), and interleukin-10 (IL-10) in restenosis after percutaneous coronary intervention (PCI).

Methods:

A total of 198 patients with acute coronary syndrome underwent coronary drug-eluting stent implantation and were divided into the restenosis group and non-restenosis group on the basis of second coronary angiography. Biological parameters and HB-EGF, IL-18, and IL-10 levels were measured. Patients in the restenosis group were further divided into 3 subgroups according to Gensini score: group A (Gensini score of <20), group B (Gensini score of >20 but <40), and group C (Gensini score of >40).

Results:

Compared with the non-restenosis group, HB-EGF and IL-18 levels were significantly higher but serum IL-10 levels were significantly lower in the restenosis group. Furthermore, HB-EGF levels increased with the Gensini score among the 3 subgroups. Spearman’s correlation analysis showed that HB-EGF levels were associated with IL-18 levels and the number of diseased vessels. Multivariate logistic regression analysis showed that diabetes, HB-EGF, and IL-18 were risk factors for restenosis [odds ratio with 95% confidence interval: 3.902 (1.188-4.415), 2.185 (1.103-4.014), and 2.079 (1.208-4.027), respectively].

Conclusion:

The present study has demonstrated that HB-EGF may be used to evaluate the severity of restenosis and coronary artery lesion and that inflammatory responses may be involved in the process of restenosis.

How bifurcation angle impacts the fate of side branch after main vessel stenting: a retrospective analysis of 1,200 consecutive bifurcation lesions in a single center

OBJECTIVES

We aimed to investigate the effect of bifurcation angle (BA) on side branch (SB) occlusion after main vessel (MV) stenting.

BACKGROUND

BA is thought to impact the risk of SB occlusion in coronary bifurcation patients undergoing percutaneous coronary intervention (PCI).

METHODS

A total of 1,171 consecutive patients with 1,200 bifurcation lesions undergoing one stent or provisional two stent techniques were studied. The lesions were divided into low angle and high angle groups using the median BA (52°). Multivariate logistic regression analysis was performed to identify independent predictors of SB occlusion.

RESULTS

SB occlusion occurred in 88 (7.33%) of 1,200 bifurcation lesions treated with the one stent technique or MV stenting first strategy. The rate of SB occlusion was significantly higher in the high angle group (63/600, 10.5%) than the low angle group (25/600, 4.2%) (P < 0.001). The rate of SB occlusion increased significantly across quartiles of BA as follows: from 3.63% in the first quartile of BA, to 4.71% in quartile II, to 8.14% in quartile III to 12.97% in quartile IV (P < 0.001). Multivariable analysis showed that high angle was an independent predictor of SB occlusion (odds ratio: 1.026, 95% confidence intervals: 1.014-1.037, P < 0.001). Plaque distribution at the same side of SB, MV Thrombolysis in Myocardial Infarction flow grade before stenting, pre-procedural diameter stenosis of bifurcation core, diameter ratio between MV/SB and diameter stenosis of SB before MV stenting were also independent predictors of SB occlusion.

CONCLUSIONS

High BA was an independent predictor of SB occlusion after MV stenting. The occlusion risk of SB with a high BA should not be ignored.

The effect of dalteparin versus unfractionated heparin on the levels of troponin I and creatine kinase isoenzyme MB in elective percutaneous coronary intervention: a multicenter study

Background

The aim of this study was to investigate the safety and efficacy of dalteparin during an elective percutaneous coronary intervention (PCI) procedure in a large cohort.

Materials and methods

In this prospective, randomized, open-label design study, 733 patients undergoing elective PCI were divided into an unfractionated heparin group (group 1, 323 patients) or a dalteparin group (group 2, 410 patients). Blood samples were collected before and 18–24 h after the PCI procedure to determine the serum levels of cardiac troponin I (cTnI) and creatine kinase isoenzyme MB. Major adverse cardiac events (MACEs) and bleeding events during hospitalization were also recorded. Patients with an increased level of serum cTnI before PCI were excluded from the study.

Results

After PCI, the cTnI values were greater than three times the upper limit of normal in 43 cases (13.3%) in group 1 and 52 cases (12.7%) in group 2, without a statistically significant difference between the two groups (P=0.801). An increased creatine kinase isoenzyme MB level of greater than two times the upper limit of normal was found in 10 cases (3.1%) in group 1 and 12 cases (2.9%) in group 2, without a statistically significant difference between the two groups (P=0.894). Postoperative bleeding was observed in nine patients (2.8%) in group 1 and six patients (1.5%) in group 2. Postoperative MACEs were observed in two patients (0.6%) in group 1 and two patients (0.5%) in group 2. There were no significant differences between the two groups with respect to bleeding events or MACEs.

Conclusion

Our study showed that dalteparin might be as effective and safe as unfractionated heparin for anticoagulation during elective PCI.

The clinical significance of cardiac troponins in medical practice

Troponins are regulatory proteins that form the cornerstone of muscle contraction. The amino acid sequences of cardiac troponins differentiate them from that of skeletal muscles, allowing for the development of monoclonal antibody-based assay of troponin I (TnI) and troponin T (TnT). Along with the patient history, physical examination and electrocardiography, the measurement of highly sensitive and specific cardiac troponin has supplanted the former gold standard biomarker (creatine kinase-MB) to detect myocardial damage and estimate the prognosis of patients with ischemic heart disease. The current guidelines for the diagnosis of non-ST segment elevation myocardial infarction are largely based on an elevated troponin level. The implementation of these new guidelines in clinical practice has led to a substantial increase in the frequency of myocardial infarction diagnosis. Automated assays using cardiac-specific monoclonal antibodies to cardiac TnI and TnT are commercially available. They play a major role in the evaluation of myocardial injury and prediction of cardiovascular outcome in cardiac and non-cardiac causes. In this review we discuss the clinical applications of cardiac troponins and the interpretation of elevated levels in the context of various clinical settings.

Effect of intracoronary nicardipine on cardiac enzymes after elective percutaneous coronary intervention

BACKGROUND

Elevation in cardiac enzymes after percutaneous coronary intervention (PCI) is common and is associated with adverse clinical outcomes.

HYPOTHESIS

Administration of intracoronary nicardipine--a calcium channel blocker will reduce cardiac enzyme levels in patients undergoing elective PCI.

METHODS

In a single center, prospective, double-blind placebo-controlled trial, 193 patients undergoing elective PCI (with or without stenting) for chronic stable angina and/or an abnormal stress test were randomized to receive 200 mcg of intracoronary nicardipine (n = 93) or saline solution (n = 100) prior to intervention. Cardiac enzyme levels were measured immediately and at 8 and 16 hours after the procedure. Major adverse clinical events (MACE) were assessed at 30 days and at 6 months.

RESULTS

Incidence of periprocedural myonecrosis defined as elevation of troponin I levels > 1x the upper limit of normal was similar in both groups (placebo 15.4% vs drug 10.6%; P = 0.47). There was no significant difference in peak troponin I levels after PCI between the 2 groups (placebo 0.58 ng/mL +/- 1.08 ng/mL vs drug 0.97 ng/mL +/- 3.6 ng/mL; P = 0.35). Major adverse clinical events at 6 months were infrequent and not statistically different in the 2 groups (placebo 3.4% vs drug 1.2%; P = 0.52). Multivariate analysis revealed that pretreatment with nicardipine was not associated with reduction in the incidence of troponin I elevation (odds ratio [OR]: 0.54; 95% confidence interval [CI]: 0.18-1.6; P = 0.28).

CONCLUSIONS

In low-risk patients undergoing elective PCI, intracoronary nicardipine administration did not produce a significant cardioprotective effect in reducing postprocedural cardiac enzymes leakage.

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.

Incidence and determinants of myocardial infarction following percutaneous coronary interventions according to the revised Joint Task Force definition of troponin T elevation

BACKGROUND

Elevations in troponin T (TnT) occur frequently following percutaneous coronary intervention (PCI) and are associated with an adverse prognosis. The Joint ESC/ACC/AHA/WHF Task Force have released a proposal for a universal definition of myocardial infarction (MI), including diagnostic criteria for PCI associated MI. This is based on a TnT cut-point of more than three times the 99th percentile (0.03 ng/ml), which better reflects the precision of the assay. Our study investigated the incidence and predictive factors of a PCI associated MI, using the revised definition.

METHODS

325 patients were studied following PCI with stenting. TnT was collected at both 8 and 18 h following PCI in patients with either stable or unstable angina and normal baseline TnT levels. Comparison was made of both clinical and procedural characteristics of patients with and without a rise in TnT following intervention, using cut points of 0.01 and 0.03 ng/ml.

RESULTS

TnT was elevated > or = 0.03 ng/ml in 27% and > or = 0.01 ng/ml in 39% of patients following PCI. Troponin elevation was significantly more likely in those patients who experienced peri-procedural ischemic symptoms or EKG changes, or in whom abciximab was used. The variables associated with a troponin rise showed a greater difference between TnT positive and negative patients when using 0.03 ng/ml compared to 0.01 ng/ml, suggesting that this may be a better definition of PCI-related MI.

CONCLUSIONS

Approximately one-quarter of low risk patients experience a procedural MI according to the revised definition. Rises in troponin were significantly associated with peri-procedural ischemic symptoms and EKG changes, and abciximab use, consistent with this level of TnT reflecting true myocardial necrosis.

Lack of consensus in biomarker measurement to diagnose PCI-related myocardial infarction

OBJECTIVE

To evaluate if biomarker sampling in PCI has adhered to the 2 000 consensus document for the diagnosis of procedure-related myocardial infarction (MI).

DESIGN

Firstly, a review of relevant papers from 2000 to September 2007 was done. Secondly, in October 2007, a questionnaire addressing biomarker sampling in routine PCI was sent to Danish PCI centres.

RESULTS

Fourteen papers fulfilled the selection criteria. In six studies serial sampling according to the consensus document had been done. Biomarker measuring before PCI was not performed in four studies. All centres answered the questionnaire. In none of six centres the proposed 3-sample testing of biomarkers had been followed. A pre-PCI sample was taken in one centre. In approximately half of the centres biomarkers were only measured on clinical indication.

CONCLUSION

Biomarker sampling for procedure-related MI according to the 2 000 consensus document has not been universally adapted. In order to avoid hampering of epidemiologic data and the comparison of future clinical trials it is proposed that the 2007 MI re-definition consensus document will be rapidly and universally accepted.

New universal definition of myocardial infarction: What is the difference?

<zakljucak> Ucinjene su brojne izmene univerzalne definicije infarkta miokarda u odnosu na verziju iz 2000. godine, ali troponin ostaje zlatni standard za opstu definiciju u miljeu karakteristicnog klinickog scenarija za ishemiju miokarda i tipicnih EKG promena. Svako povecanje troponina ne znaci istovremeno i definitivno infarkt miokarda. Postoje i mnogi drugi uzroci porasta troponina. Nekroza miokarda nije uvek posledica ishemije, vec postoje i druge nokse koje mogu dovesti do smrti celija miokarda. U novim preporukama navodi se da je troponin 'izabrani' marker, ali i drugi biomarkeri, pre svega MB frakcija kreatinin kinaze, mogu biti dovoljni, ako nije dostupan test sa troponinom. Ostale inovacije ukljucuju kriterijume za infarkt miokarda kao uzrocnika naprasne smrti i posebna tezina koja se daje nalazima dobijenim ehokardiografski, perfuzionom scintigrafijom i ostalim neinvazivnim metodama. Jedan od ciljeva ovog konsenzusa je da se utvrde specificni kriterijumi za postavljenje dijagnoze infarkta miokarda koji ce biti moderni, prakticni i relevantni u svakoj prilici sirom sveta. Ideja je bila da se definicija standardizuje tako da sve klinicke studije i svi ljudi u bolnicama sirom sveta budu 'na istoj talasnoj duzini'.

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.

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.

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.

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.

Elevated troponin-I after percutaneous coronary interventions: Incidence and risk factors

BACKGROUND

Percutaneous coronary interventions (PCIs) are often complicated by postprocedural myocardial necrosis as manifested by elevated cardiac markers.

PURPOSE

To assess the incidence and risk factors of elevated troponin-I (TnI) after PCI.

METHODS AND RESULTS

We performed a retrospective analysis on 522 PCI cases over a 1-year period at a single center. An elevated postprocedural TnI (>1.0 ng/ml) occurred in 213 patients (40.8%). Overall, glycoprotein (GP) IIb/IIIa inhibitors were used in 52% of cases. Baseline clinical characteristics were similar between the positive and the negative TnI groups. A univariate analysis revealed that patients with elevated TnI post-PCI had significantly more multivessel (28% vs. 15%, P = .001) and multilesion interventions (44% vs. 27%, P<.0001). The lesions were longer, more often angulated and involving bifurcations, and more complex in the TnI-positive group. Stent use and number of stents was higher in the TnI-positive group, and longer inflation times (>30 s) or higher inflation pressures (>14 atm) were used more often in the TnI-positive group. GP IIb/IIIa inhibitor use was higher in the TnI-positive group (61% vs. 45%, P = .0007). After multivariable analysis, independent predictors of elevated TnI after PCI included multilesion intervention, lesion length, lesion angulation, and GP IIb/IIIa inhibitor use.

CONCLUSION

TnI is elevated in approximately 40% of cases after PCI. TnI is more likely to be elevated after intervention on multiple lesions, angulated or long lesions.

Role of cardiac troponin testing in percutaneous transluminal coronary angioplasty

Percutaneous transluminal coronary angioplasty (PTCA) is a common invasive procedure for myocardial revascularization. This article reviews the role of monitoring cardiac troponins in identifying procedural myocardial damage as a result of PTCA, its associations with balloon inflation time, stenting, side-branch occlusion and the prognostic implications of elevated levels of cardiac troponins. A review of several studies demonstrates that cardiac troponins are more sensitive than creatine kinase MB, CK-MB (mass) in detecting minor myocardial damage during PTCA. Increases in post-procedural cardiac troponin T and cardiac troponin I are associated with a greater degree of morbidity and mortality. Increases are more common and more pronounced following a longer duration of balloon inflation time, stenting and side-branch occlusion. Elevated cardiac troponins pre-procedure are a poor prognostic indicator.

Predicting cancer therapy-induced cardiotoxicity: the role of troponins and other markers

Several anticancer drugs have been associated with cardiac toxicity, especially the anthracyclines and trastuzumab. The pathogenesis of anthracycline-associated toxicity has been well described, whereas the mechanism of trastuzumab-associated toxicity is unknown. Although routine cardiac imaging studies (e.g. echocardiogram or multiple gated acquisition scans) may identify subclinical evidence of myocardial dysfunction, available data do not support their routine use for monitoring asymptomatic patients undergoing cancer therapy. Other modalities such as nuclear medicine scintigraphy with indium-111-antimyosin antibody and endomyocardial biopsy have been shown to be useful in identifying early cardiac damage, but their routine use is limited by practical considerations such as feasibility and cost. Consequently, there is significant interest in developing simple and reproducible methods for identifying patients at risk for treatment-induced myocardial damage. Available data suggest that circulating markers such as troponins and natriuretic peptides could potentially be useful for this purpose. Measurement of plasma troponin levels are commonly used in clinical practice in order to provide diagnostic and prognostic information in patients with myocardial ischaemia. Elevated levels may likewise correlate with anthracycline-induced cardiac damage, although plasma levels are only minimally elevated (well below that associated with ischaemia), and elevations may persist for weeks or months after anthracycline exposure. Clinical trials are currently evaluating the role of these markers in predicting both early and late, clinical and subclinical damage associated with anthracyclines and trastuzumab.