Peri-procedural myocardial injury: 2005 update

Atorvastatin pretreatment diminishes the levels of myocardial ischemia markers early after CABG operation: an observational study

Background

Statin pretreatment has been associated with a decrease in myocardial ischemia markers after various procedures and cardiovascular events. This study examined the potential beneficial effects of preoperative atorvastatin treatment among patients undergoing on-pump CABG operation.

Methods

Twenty patients that had received atorvastatin treatment for at least 15 days prior to the operation and 20 patients who had not received any antihyperlipidemic agent prior to surgery were included in this study. CK-MB and troponin I levels were measured at baseline and 24 hours after the operation. Perioperative variables were also recorded.

Results

Twenty-four hours after the operation, troponin I and CK-MB levels were significantly lower in the atorvastatin group: for CK-MB levels, 12.9 ± 4.3 versus 18.7 ± 7.4 ng/ml, p = 0.004; for troponin I levels, 1.7 ± 0.3 versus 2.7 ± 0.7 ng/ml, p < 0.001. In addition, atorvastatin use was associated with a decrease in the duration of ICU stay.

Conclusions

Preoperative atorvastatin treatment results in significant reductions in the levels of myocardial injury markers early after on-pump CABG operation, suggesting a reduction in perioperative ischemia in this group of patients. Further studies are needed to elucidate the mechanisms of these potential benefits of statin pretreatment.

Effect of statins pretreatment on periprocedural myocardial infarction in patients undergoing percutaneous coronary intervention: a meta-analysis

BACKGROUND

Periprocedural myocardial injury remains the most common complication associated with percutaneous coronary intervention (PCI). Previous studies have demonstrated that even a small elevation of cardiac enzymes is associated with higher risk of mortality during follow-up.

OBJECTIVE

We performed a meta-analysis based on all currently available randomized controlled trials (RCT) to evaluate the beneficial effects of hydroxymethylglutaryl-CoA reductase inhibitors (statins) given before PCI on preventing periprocedural myocardial infarction (MI).

METHODS

The published literature was scanned by formal searches of electronic databases (PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials) and conference proceedings up through August 2009. RCTs were eligible for inclusion if they compared preprocedural statins versus placebo treatment in patients not taking statins previously but scheduled for PCI and had the data of periprocedural MI reported by the trial investigators.

RESULTS

Prespecified criteria were met by 6 RCTs involving 2,088 patients. During the periprocedural period, 81 of 1,051 patients (7.7%) in the statins pretreatment group developed periprocedural MI, significantly less than 147 of 1,037 (14.2%) patients assigned to the control group (OR 0.51, 95% CI 0.38-0.67; P< 0.001). During 1-month follow-up, only 4 deaths, 7 non-periprocedural Q-wave MIs, and 4 revascularizations occurred in all 2,088 enrolled patients. The composite of death, MI, or target vessel revascularization at 1 month, essentially driven by periprocedural MI, was reported in 8.0% in the statins pretreatment group and 15.3% in the control group (OR 0.48, 95% CI 0.36-0.64; P< 0.001).

CONCLUSIONS

This meta-analysis supports the effectiveness of statins pretreatment on reducing the rate of periprocedural MI in patients undergoing PCI.

Coronary microembolization: from bedside to bench and back to bedside

Coronary microembolization from the erosion or rupture of a vulnerable atherosclerotic plaque occurs spontaneously in acute coronary syndromes and iatrogenically during percutaneous coronary interventions. Typical consequences of coronary microembolization are microinfarcts with an inflammatory response, contractile dysfunction, and reduced coronary reserve. Apart from transient elevations of creatine kinase and troponin, microemboli can be visualized by intracoronary Doppler and the resulting microinfarcts by late-enhancement nuclear magnetic resonance. Statins, antiplatelet agents, and coronary vasodilators protect against microembolization and microinfarction when started before percutaneous coronary interventions. Distal protection devices can retrieve atherothrombotic debris and prevent its embolization into the microcirculation, but their effect on clinical outcome has been disappointing so far, except for saphenous vein bypass grafts. Devices for aspiration of thrombi and thrombus-derived vasoconstrictor, thrombogenic, and inflammatory substances, however, reduce thrombus burden, improve perfusion, and provide protection in patients with acute myocardial infarction.

Comparison of bivalirudin monotherapy versus unfractionated heparin plus tirofiban in patients with diabetes mellitus undergoing elective percutaneous coronary intervention

Bivalirudin demonstrated similar efficacy but resulted in a lower rate of bleeding compared to unfractionated heparin (UFH) plus platelet glycoprotein IIb/IIIa inhibitors in patients undergoing percutaneous coronary intervention. It has not been clearly evaluated whether this can also be applied to patients with diabetes mellitus. A total of 335 consecutive patients with diabetes mellitus referred for elective percutaneous coronary intervention were randomized in the Novel Approaches for Preventing or Limiting EventS (NAPLES) trial to receive bivalirudin monotherapy or UFH plus routine tirofiban. The primary composite end point (30-day composite incidence of death, urgent repeat revascularization, myocardial infarction, and all bleeding) was lower in the bivalirudin group than in the UFH plus tirofiban group (18.0% vs 31.5%, odds ratio 0.47, 95% confidence interval 0.28 to 0.79, p = 0.004). No death, urgent revascularization, or Q-wave myocardial infarction occurred. The rate of non-Q-wave myocardial infarction was similar in the 2 groups (10.2% in the bivalirudin group vs 12.5% in the UFH plus tirofiban group, p = 0.606). In contrast, fewer patients in the bivalirudin group experienced bleeding (8.4% vs 20.8%, odds ratio 0.34, 95% confidence interval 0.18 to 0.67, p = 0.002). This difference was mainly ascribed to the lower rate of minor bleeding (7.8% in the bivalirudin group vs 18.5% in the UFH plus tirofiban group, odds ratio 0.37, 95% confidence interval 0.19 to 0.74, p = 0.005), although the rate of major bleeding in the 2 groups was comparable (0.6% vs 2.4%, respectively; p = 0.371). In conclusion, in patients with diabetes mellitus undergoing elective percutaneous coronary intervention, the strategy of bivalirudin monotherapy compared to UFH plus routine tirofiban is safe and feasible and associated with a significant reduction of in-hospital bleeding.

Effect of two-day atorvastatin pretreatment on the incidence of periprocedural myocardial infarction following elective percutaneous coronary intervention: a single-center, prospective, and randomized study

Both randomized and observational studies have suggested that pretreatment with statins may reduce the incidence of periprocedural myocardial infarction (PMI) in patients with stable angina during elective percutaneous coronary intervention (PCI). The purpose of this randomized study (Clinical Trial Registration No. NCT00469326) was to investigate the effect of 2-day atorvastatin therapy on the incidence of PMI in patients with stable angina pectoris undergoing elective PCI. A total of 200 patients with stable angina pectoris who were not taking statins and who had been referred for PCI were enrolled and randomized (ratio 1:1) to a 2-day pretreatment regimen with atorvastatin 80 mg/day and subsequent PCI or immediate PCI. The serum concentration of creatine kinase-MB mass and troponin I were measured before and 16 to 24 hours after PCI. The incidence of PMI was assessed using established criteria. Of the patients, 10% in the atorvastatin group and 12% in the control group had a postprocedural creatine kinase-MB mass elevation > or =3 times the upper limit of normal (p = 0.65). The incidence of PMI as determined by the postinterventional release of troponin I > or =3 times the upper limit of normal was 17% in the atorvastatin group and 16% in the control group (p = 0.85). The median creatine kinase-MB mass peak after PCI was 1.46 ng/ml (interquartile range 0.83 to 2.52) in the atorvastatin group and 1.40 ng/ml (interquartile range 0.90 to 2.54) in the control group (p = 0.70). The median peak troponin I level after PCI was 0.100 ng/ml (0.096 to 0.385) in the atorvastatin group and 0.100 ng/ml (0.60 to 0.262) in the control group (p = 0.54). On multivariate analysis, the only independent predictor of PMI was patient age (odds ratio 1.09, 95% confidence interval 1.025 to 1.159, p = 0.006). In conclusion, in the present study 2-day pre-PCI therapy with atorvastatin did not reduce the occurrence of PMI in patients with stable angina pectoris undergoing elective PCI.

The effect of previous coronary artery stenting on short- and intermediate-term outcome after surgical revascularization in patients with diabetes mellitus

OBJECTIVES

Percutaneous intervention for coronary revascularization is associated with an increased risk of repeat revascularization, especially in patients with diabetes mellitus. In this study we sought to examine the effect of previous percutaneous intervention on the rate of adverse perioperative outcome and intermediate-term survival in patients undergoing coronary artery bypass surgery.

METHODS

Between January 1, 2001, and December 31, 2006, 1758 consecutive patients with diabetes mellitus who underwent first-time isolated coronary artery bypass surgery were identified. Survival and major perioperative complications for 1537 patients who did not have prior percutaneous intervention (group 1) were compared with those in 221 patients with prior percutaneous intervention (group 2) after adjusting for baseline risk factors. Vital status was determined by using the National Death Index and Social Security Death Index. Age-adjusted survival at 2 years' follow-up was calculated with the Cox singular proportional hazards model.

RESULTS

At baseline, group 2 patients had higher incidences of hypercholesterolemia and myocardial infarction. Compared with group 1 patient, group 2 patients had significantly higher operative mortality (adjusted odds ratio, 4.05; 95% confidence interval, 1.41-11.63), perioperative major adverse cardiac events (adjusted odds ratio, 2.72; 95% confidence interval, 1.08-6.85), and atrial fibrillation (adjusted odds ratio, 1.97; 95% confidence interval, 1.29-3.01). Group 2 patients had worse age-adjusted survival at 2 years' follow-up (93.4% vs 87.4%, P < .017).

CONCLUSIONS

Patients with diabetes mellitus and a history of percutaneous coronary stenting before coronary artery bypass surgery were found to have an increased risk of operative death, increased perioperative complications, and decreased age-adjusted survival at 2 years' follow-up.

Associations of major bleeding and myocardial infarction with the incidence and timing of mortality in patients presenting with non-ST-elevation acute coronary syndromes: a risk model from the ACUITY trial

AIMS

To evaluate the associations of myocardial infarction (MI) and major bleeding with 1-year mortality. Both MI and major bleeding predict 1-year mortality in patients presenting with acute coronary syndrome (ACS). However, the risk of each of these events on the magnitude and timing of mortality has not been well studied.

METHODS AND RESULTS

A multivariable Cox regression model was developed relating 13 independent baseline predictors to 1-year mortality for 13 819 patients with moderate and high-risk ACS enrolled in the Acute Catheterization and Urgent Intervention Triage strategy trial. After adjustment for baseline predictors, Cox models with major bleeding and recurrent MI as time-updated covariates estimated the effect of these events on mortality hazard over time. Within 30 days of randomization, 705 patients (5.1%) had an MI, 645 (4.7%) had a major bleed; 524 (3.8%) died within a year. The occurrence of an MI was associated with a hazard ratio of 3.1 compared with patients not yet having an MI, after adjustment for baseline predictors. However, MI within 30 days markedly increased the mortality risk for the first 2 days after the event (adjusted hazard ratio of 17.6), but this risk declined rapidly post-infarct (hazard ratio of 1.4 beyond 1 month after the MI event). In contrast, major bleeding had a prolonged association with mortality risk (hazard ratio of 3.5) which remained fairly steady over time throughout 1 year.

CONCLUSION

After accounting for baseline predictors of mortality, major bleeds and MI have similar overall strength of association with mortality in the first year after ACS. MI is correlated with a dramatic increase in short-term risk, whereas major bleeding correlates with a more prolonged mortality risk.

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.

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.

Relation of low response to clopidogrel assessed with point-of-care assay to periprocedural myonecrosis in patients undergoing elective coronary stenting for stable angina pectoris

Impaired responses to antiplatelet therapy assessed by laboratory tests are associated with an increased risk of recurrent ischemic events after percutaneous coronary intervention (PCI). This study was designed to determine the relation between responses to aspirin and clopidogrel as assessed by a point-of-care assay (Verify Now, Accumetrics, San Diego, California) and periprocedural myocardial infarction (PMI) in patients undergoing elective PCI for stable angina. One hundred twenty-two consecutive patients undergoing elective coronary stenting prospectively received aspirin 500 mg and clopidogrel 600 mg >or=12 hours before PCI. Clopidogrel response was measured with P2Y12 reaction units (PRUs) and percent inhibition P2Y12 from baseline (percent inhibition P2Y12) and aspirin response with aspirin reaction units (ARUs). Troponin T level was considered positive if it was >0.03 ng/ml. Responses to aspirin and clopidogrel were correlated (r=0.42, p <0.0001). PMI occurred in 27 patients (22%) who showed significantly lower percent inhibition P2Y12 (25.3+/-26 vs 38.3+/-25, p=0.01) and a trend toward higher PRU values (221+/-87 vs 193+/-94, p=0.21). We did not find any difference for aspirin response as assessed by ARUs in patients with or without PMI (460+/-82 vs 454+/-73, p = 0.82). Stratification of percent inhibition P2Y12 isolated a quartile of clopidogrel nonresponders (inhibition P2Y12 <15%) with significantly higher incidence of PMI (44% vs 15%, odds ratio 4.6, 95% confidence interval 1.9 to 11.5, p=0.001). In conclusion, point-of-care assessment of clopidogrel response reliably predicted PMI after low- to medium-risk elective PCI for stable angina.

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.

HDL and its sphingosine-1-phosphate content in cardioprotection

Increasing evidence suggests that High-density lipoproteins (HDL) are a direct cardioprotective agent in the setting of acute myocardial ischemia/reperfusion injury, and that this cardioprotection occurs independently of their atheroprotective effect. Studies on the involved mechanisms have revealed that the biologically active HDL-compound sphingosine-1-phosphate (S1P) is responsible for the beneficial effect of HDL on the myocardium. There appears to be an intricate interplay between known preconditioning agents and components of the S1P synthesis machinery in the heart, which makes S1P signalling an attractive downstream convergence point of preconditioning and cardioprotection at the level of its G protein-coupled receptors. While local S1P production has been known to protect the heart against ischemia/reperfusion injury and to mediate preconditioning, systemic S1P supply via HDL adds a novel aspect to the regulation of cardioprotection. Thus the S1P-content of HDL may serve both as a potential cardiovascular risk marker and a novel therapeutic target. Strategies for short-term "acute" HDL elevation as well as S1P analogues may prove beneficial not only in the high-risk patient but also in any patient at risk of myocardial ischemia.

Troponin T elevation and prognosis after multivessel compared with single-vessel elective percutaneous coronary intervention

BACKGROUND.: Although techniques for percutaneous coronary intervention (PCI) have improved, patients with PCI of more vessels may still have an increased risk. We performed a prospective observational study evaluating the differences between multivessel and single-vessel procedures according to postprocedural troponin T (TnT) elevation and events during follow-up. METHODS.: The study included 713 patients without elevated TnT (<0.05 ng/ml) before PCI. Primary endpoint was the combined endpoint of death, myocardial infarction, stroke, repeat coronary angiography and readmission for anginal symptoms during the mean follow-up of 10.9 months. RESULTS.: TnT after PCI was elevated in 150 patients (21%) and was significantly associated with an increased incidence of the primary endpoint (RR 1.55, 95% CI 1.01 to 2.38). PCI of more than one vessel was performed in 146 patients (20%). These patients more often had increased TnT levels after the procedure (31.5 vs. 18.3%, p=0.001) and an increased incidence of the primary endpoint during follow-up (28 vs. 19%, p=0.01). After multivariable analysis, multivessel PCI was a statistically significant predictor of postprocedural TnT increase (OR 1.90, 95% CI 1.17 to 3.06). Multivessel PCI was also associated with an increased risk of the primary endpoint (OR 1.73, 95% CI 1.18 to 2.52), but after adjusting for multivessel disease this association was not statistically significant (OR 1.42, 95% CI 0.92 to 2.19). CONCLUSION.: Elective PCI of more vessels in one session is, in comparison with single-vessel PCI, more often associated with postprocedural troponin T rise and a (nonsignificantly) higher incidence of cardiac events during follow-up. Whether staged PCI is associated with less morbidity has to be assessed. (Neth Heart J 2007;15:178-83.).

A study comparing the incidence and predictors of creatine kinase MB and troponin T release after coronary angioplasty. Does Clopidogrel preloading reduce myocardial necrosis following elective percutaneous coronary intervention?

BACKGROUND

To investigate the incidence and associated factors for enzyme release following percutaneous coronary intervention comparing assessment with creatine kinase MB (CK-MB) and troponin T (TnT).

METHOD

TnT and CK-MB were measured post procedure in a consecutive series of 933 patients undergoing elective percutaneous coronary intervention between 1/4/2003 and 1/5/2004 at a single regional cardiac centre.

RESULTS

CK-MB level significantly correlated to TnT levels (R=0.747, p<0.001) and a CK-MB level of above 3 times the upper limit of the local reference range (>3 x ULN) was predicted with 95% sensitivity (48% specificity) at a TnT level of 0.11. Multivariate predictors of >3 x ULN CK-MB release for uncomplicated percutaneous coronary intervention (n=898) were multi-vessel angioplasty (OR=2.51, 95% CI=1.57 to 4.01; p<0.001), saphenous venous graft angioplasty (OR=5.5, 95% CI=1.94 to 13.00; p=0.005) and lack of Clopidogrel preloading (OR=2.02, 95% CI=1.30 to 4.38; p=0.027).

CONCLUSIONS

TnT was found to be a sensitive although not a highly specific marker of CK-MB release. In this study a TnT level above a threshold of 0.11 would identify 95% of the prognostically important 3-fold CK-MB releases. Replacing the >3 x ULN CK-MB threshold with a TnT level of 0.1 ng/l following percutaneous coronary intervention would increase the apparent rate of myocardial infarction from 11% to 20%. Lack of Clopidogrel preloading was independently associated with a >3 x ULN CK-MB release following uncomplicated elective percutaneous coronary intervention.

Detection of Coronary Microembolization by Doppler Ultrasound in Patients With Stable Angina Pectoris Undergoing Elective Percutaneous Coronary Interventions

Background— Intracoronary Doppler guidewires can be used for real-time detection and quantification of microembolism during percutaneous coronary interventions (PCIs). We investigated whether the frequency of Doppler-detected microembolism is related to the incidence of myonecrosis during elective PCI.

Methods and Results— The study population included 52 consecutive patients (aged 64±10 years; 36 men, 16 women) with coronary artery disease who underwent elective PCI of a single-vessel stenosis. Using intracoronary Doppler ultrasound, we compared the frequency of microembolism during PCI in 22 patients with periprocedural non–ST-segment elevation myocardial infarctions (pNSTEMI) and 30 patients without pNSTEMI. The 2 groups were comparable with regard to their clinical and procedural characteristics. In the group with pNSTEMI, the total number of coronary microemboli after PCI (27±10 versus 16±8, P <0.001) was higher than in the group without pNSTEMI. Although high-sensitivity C-reactive protein plasma levels were similar before PCI (2.9±2.2 versus 3.4±1.7 mg/L, P =NS), they were higher in the group with pNSTEMI after PCI (12.6±10.4 versus 6.1±5.1 mg/L, P <0.05). Microembolic count independently correlated to postprocedural cardiac troponin I elevation ( r =0.565, P <0.001), coronary flow velocity reserve ( r =−0.506, P <0.001), and baseline average peak velocity ( r =0.499, P <0.001).

Conclusions— Patients with pNSTEMI had a significantly higher frequency of coronary microembolization during PCI, and their systemic inflammatory response and microvascular impairment after PCI were more pronounced. Intracoronary Doppler ultrasound provides evidence that pNSTEMI in patients undergoing elective PCI is caused by microembolization during the procedure.

Biomarkers of cardiovascular damage

Acute coronary syndromes (ACS) are due to the rupture or erosion of atheromatous plaques. This produces, depending on plaque size, vascular anatomy and degree of collateral circulation, progressive tissue ischaemia which may progress to cardiomyocyte necrosis. This may then result in cardiac remodelling. Serum biomarkers are available which can be used for diagnosis of all of these stages. Markers to detect myocardial ischaemia at the pre-infarction stage are potentially the most interesting but also the most challenging. An ischaemia marker offers the opportunity to intervene to prevent progression to infarction. The problems with potential ischaemia markers are specificity and the reference diagnostic standard against which they can be judged. To date, only one, ischaemia-modified albumin(R), has reached the point where clinical studies can be performed. The measurement of the cardiac troponins, cardiac troponin T and cardiac troponin I, have become recognised as the diagnostic reference standard for myocardial necrosis. The sensitive nature of these tests has also revealed that myocardial necrosis is also found in a range of other clinical situations, highlighting the need to use all clinical information for diagnosis of acute myocardial infarction. The measurement of B-type natriuretic peptides can be shown to be diagnostic and prognostic in both ACS and detecting the sequelae of post-infarction myocardial insufficiency. The role of the B-type natriuretic peptides in detection of cardiac failure, both acute and chronic, is well defined but remains the subject of further studies, in ACS.

Biomarkers of Cardiovascular Damage and Dysfunction—An Overview

Acute coronary syndromes (ACS) are due to the rupture or erosion of atheromatous plaques. This produces, depending on plaque size, vascular anatomy and degree of collateral circulation, progressive tissue ischaemia which may progress to cardiomyocyte necrosis and subsequent cardiac remodelling. Cardiac biomarkers can be used for diagnosis and assessment of all of these stages. Markers to detect myocardial ischaemia at the pre-infarction stage are potentially the most interesting but also the most challenging. An ischaemia marker offers the opportunity to intervene to prevent progression to infarction. The challenges with potential ischaemia markers are specificity and the diagnostic reference standard for assessment. To date, only one, ischaemia modified albumin, has reached the point where clinical studies can be performed. The measurement of the cardiac troponins, cardiac troponin T and cardiac troponin I, has become the diagnostic standard as the biomarker of myocardial necrosis. The sensitive nature of troponin measurement has also revealed that myocardial necrosis is also found in a range of other clinical situations. This illustrates the need to use all clinical information for diagnosis of acute myocardial infarction. The measurement of B type natriuretic peptides can be shown to be diagnostic and prognostic for both acute ACS and detecting the sequelae of post infarction myocardial insufficiency. The role of the B type natriuretic peptides in detection of cardiac failure, acute and chronic, is well defined. Their role in ACS remains the subject of further studies.

Intracoronary ST-Segment Shift Soon After Elective Percutaneous Coronary Intervention Accurately Predicts Periprocedural Myocardial Injury

Background— Elevation of cardiac biomarkers after coronary angioplasty (percutaneous coronary intervention [PCI]) reflects periprocedural myocardial damage and is associated with adverse cardiac events. We assessed whether periprocedural myocardial damage that occurs despite successful PCI could be rapidly and easily identified by intracoronary ST-segment recording with the use of a catheter guidewire.

Methods and Results— In 108 consecutive stable patients undergoing elective single-vessel PCI, we recorded unipolar ECG from the intracoronary guidewire in the distal coronary before PCI and 2 minutes after the last balloon inflation. After PCI, intracoronary ST-segment shift ≥1 mm from baseline was considered significant. Troponin I levels were measured at baseline and at 8 and 24 hours after intervention, and myocardial damage was defined as troponin I increase above the upper normal value after intervention. All patients had normal cardiac marker values before PCI, and PCI was successful in all (residual stenosis <20%, Thrombolysis in Myocardial Infarction grade 3 flow). After PCI, long-term follow-up data were collected; myocardial damage was detected in 50 patients (46%), although abnormal creatine kinase-MB values were documented in only 11 (10%). Significant intracoronary ST-segment shift after PCI was present in 40 patients (37%; group A) and absent in the remaining 68 (63%; group B). Procedural myocardial damage was documented in 37 group A patients (93%) and in 13 group B patients (19%; P <0.001); significant ECG changes were found on standard ECG after intervention in only 5 patients (13%) and 1 patient (1%) ( P <0.05). Sensitivity of intracoronary ST-segment shift for predicting myocardial damage was 74%, and specificity was 95%, with positive and negative predictive values of 93% and 81%, respectively. On multivariate analysis, intracoronary ST-segment shift was the sole independent predictor of myocardial damage (odds ratio, 54.1; 95% confidence interval, 12.1 to 240; P <0.0001). At a median follow-up of 12±5 months, major coronary event–free survival was significantly worse in group A patients (log-rank test χ 2 =4.0; P <0.05).

Conclusions— After successful single-vessel PCI, intracoronary ST-segment shift allows the prompt and inexpensive identification of patients developing myocardial injury, who may require adjunctive therapy and longer in-hospital stay.

Prognostic Significance of Multiple Previous Percutaneous Coronary Interventions in Patients Undergoing Elective Coronary Artery Bypass Surgery

Background— A possible relationship between increased perioperative risk during coronary artery bypass grafting (CABG) and previous percutaneous coronary intervention (PCI) is debatable. We sought to determine the impact of previous PCI on patient outcome after elective CABG.

Methods and Results— Between January 2000 and January 2005, 2626 consecutive patients undergoing first-time isolated elective CABG as the primary revascularization procedure (group 1) were evaluated for in-hospital mortality and major adverse cardiac events (MACEs) and were compared with 360 patients after single PCI (group 2) and with 289 patients after multiple PCI sessions (group 3) before elective CABG. Unadjusted univariate and risk-adjusted multivariate logistic-regression analysis revealed previous multiple PCIs to be strongly associated with in-hospital mortality (odds ratio [OR], 2.24; 95% confidence interval [CI], 1.52 to 3.21; P <0.001) and MACEs (OR, 2.28; 95% CI, 1.38 to 3.59; P <0.001). To control for selection bias, a computed propensity-score matching based on 13 patient characteristics and preoperative risk factors was performed separately comparing group 1 versus 2 and group 1 versus 3. After propensity matching, conditional logistic-regression analysis confirmed previous multiple PCIs to be strongly associated with in-hospital mortality (OR, 3.01; 95% CI, 1.51 to 5.98; P <0.0017) and MACEs (OR, 2.31; 95% CI, 1.45 to 3.67; P <0.0004).

Conclusions— In patients with a history of multiple PCI sessions, perioperative risk for in-hospital mortality and MACEs during subsequent elective CABG is increased.

The role of vasodilators in the prevention and treatment of no-reflow following percutaneous coronary intervention

The routine use of vasodilators in patients with acute coronary syndromes or other groups undergoing percutaneous coronary intervention (PCI) cannot be recommended at present. However, in the event of no-reflow occurring following PCI, intracoronary adenosine or verapamil should be administered.