Increased CK-MB release is a "trade-off" for optimal stent implantation: an intravascular ultrasound study.
(73/344)
OBJECTIVES: We sought to determine the impact of aggressive stent expansion on creatine kinase-MB isoenzyme (CK-MB) release and clinical restenosis. BACKGROUND: Elevation of CK-MB after percutaneous coronary interventions has been associated with late mortality. METHODS: We identified 989 consecutive patients who underwent intravascular ultrasound-guided stenting of 1,015 coronary lesions. Patients were divided into three groups according to stent expansion, defined as the ratio of final lumen over the reference lumen cross-sectional areas: Group 1 (ratio <70%, n = 117 patients with 126 lesions); Group 2 (ratio 70% to 100%, n = 551 patients with 562 lesions); Group 3 (ratio >100%, n = 321 patients with 327 lesions). RESULTS: The peak CK-MB values increased significantly with increasing stent expansion: CK-MB = 3 to 5x normal occurred 16%, 18%, and 25% in Groups 1, 2, and 3, respectively, p = 0.02; CK-MB >5 times normal occurred 9%, 13%, and 16% respectively, p = 0.02. Conversely, at one year follow-up there was a stepwise decrease in target lesion revascularization (11% vs. 19% and 17%, respectively, p = 0.04) and major adverse cardiac events with increasing stent expansion. In addition, there was a trend toward lower mortality in Group 3 (9% vs. 4.4% vs. 4.0%, p = 0.07). CONCLUSIONS: Intravascular ultrasound-guided stent overexpansion (final lumen greater than reference lumen cross-sectional area) is accompanied by a higher periprocedural CK-MB release but a lower target lesion revascularization and a trend toward lower mortality at one year. Increased periprocedural CK-MB release appears as a trade-off for optimal stent implantation and lower clinical restenosis. (+info)
Rates of positive cardiac troponin I and creatine kinase MB mass among patients hospitalized for suspected acute coronary syndromes.
(74/344)
BACKGROUND: Cardiac troponin I (cTnI) is a more specific and sensitive biomarker than creatine kinase MB (CKMB) for detection of myocardial damage. We report the prevalence of positive cTnI and CKMB mass among patients hospitalized with suspected acute coronary syndrome (ACS) and the potential impact of use of different reference cutoffs, particularly those proposed by European Society of Cardiology/American College of Cardiology (ESC/ACC) consensus guidelines, on rates of diagnosis of acute myocardial infarction (AMI). METHODS: We analyzed 1719 consecutive patients with suspected ACS admitted to an urban acute care hospital over a 6-month period. Patients (> or = 18 years of age) had at least two separate sets of plasma biomarkers (cTnI and CKMB) measured more than 12-24 h after admission to determine the potential rates of AMI based on different biomarker cutoff concentrations. RESULTS: The prevalence of cTnI-positive cases ranged from 10.6%, based on a cutoff of twice the ROC curve (cTnI < or =1.2 microg/L), to 25.0%, using the ESC/ACC-recommended 99th percentile cutoff (cTnI <0.1 microg/L). The prevalence of CKMB-positive cases ranged from 10.4%, with the cutoff of twice the ROC curve (CKMB < or =10.0 microg/L) to 21.7%, with the 99th percentile cutoff (CKMB <3.9 microg/L). Use of the 10% CV cutoff (cTnI < or =0.3 microg/L and CKMB <3.9 microg/L) instead of the ROC cutoff produced a 26% increase in all cTnI-positive cases. Use of the 99th percentile reference cutoff instead of the ROC curve-derived cutoff produced an 85% increase in all cTnI-positive cases. A substantial proportion of the increase in total cTnI-positive cases was derived from cTnI-positive/CKMB-negative cases: 71 (4.1%), 73 (4.2%), 98 (5.7%), and 209 (12.2%) of cTnI-positive cases were CKMB-negative, as determined by the twice the ROC, ROC, 10% CV, and 99th percentile reference cutoffs, respectively. At the 99th percentile cutoffs, 8.8% of cases were CKMB-positive/cTnI-negative. CONCLUSIONS: Use of lower reference cutoffs for plasma biomarkers, as recommended by ESC/ACC guidelines, markedly increases the rates of cTnI-positive cases overall. A substantial proportion of the increase in total cTnI-positive cases was derived from the creation of additional cTnI-positive/CKMB-negative cases. CKMB-positive/cTnI-negative cases are likely false positive for myocardial injury. (+info)
Cardiac troponin I in acute pericarditis.
(75/344)
OBJECTIVES: This study was designed to investigate the prognostic value of cardiac troponin I (cTnI) in viral or idiopathic pericarditis. BACKGROUND: Idiopathic acute pericarditis has been recently reported as a possible cause of nonischemic release of cTnI. The prognostic value of this observation remains unknown. METHODS: We enrolled 118 consecutive cases (age 49.2 +/- 18.4 years; 61 men) within 24 h of symptoms onset. A highly sensitive enzymoimmunofluorometric method was used to measure cTnI (acute myocardial infarction [AMI] threshold was 1.5 ng/ml). RESULTS: A cTnI rise was detectable in 38 patients (32.2%). The following characteristics were more frequently associated with a positive cTnI test: younger age (p < 0.001), male gender (p = 0.007), ST-segment elevation (p < 0.001), and pericardial effusion (p = 0.007) at presentation. An increase beyond AMI threshold was present in nine cases (7.6%), with an associated creatine kinase-MB elevation, a release pattern similar to AMI, and echocardiographic diffuse or localized abnormal left ventricular wall motion without detectable coronary artery disease. After a mean follow-up of 24 months a similar rate of complications was found in patients with a positive or a negative cTnI test (recurrent pericarditis: 18.4 vs. 18.8%; constrictive pericarditis: 0 vs. 1.3%, for all p = NS; no cases of cardiac tamponade or residual left ventricular dysfunction were detected). CONCLUSIONS: In viral or idiopathic acute pericarditis cTnI elevation is frequently observed and commonly associated with young age, male gender, ST-segment elevation, and pericardial effusion at presentation. cTnI increase is roughly related to the extent of myocardial inflammatory involvement and, unlike acute coronary syndromes, is not a negative prognostic marker. (+info)
Impaired renal clearance explains elevated troponin T fragments in hemodialysis patients.
(76/344)
BACKGROUND: Patients with severe renal dysfunction often have unexplained elevated serum concentrations of cardiac troponin T (cTnT). We investigated whether in vivo fragmentation of cTnT could explain these increases. METHODS AND RESULTS: cTnT, creatine kinase isoenzyme MB, and myoglobin serum concentrations were measured in all 63 dialysis patients of our in-hospital dialysis department. A highly sensitive immunoprecipitation assay, followed by electrophoresis and Western blotting, was used to extract and concentrate cTnT and its possible fragments from serum of these 63 hemodialysis patients. Although creatine kinase isoenzyme MB values excluded recent ischemic myocardial events in 55 of the 63 cases, cTnT fragments ranging in size from 8 to 25 kDa were present in the serum samples of all dialysis patients. CONCLUSIONS: cTnT is fragmented into molecules small enough to be cleared by the kidneys of healthy subjects. Impaired renal function causes accumulation of these cTnT fragments and is very likely the cause of the unexplained elevations of serum cTnT found in patients with severe renal failure. (+info)
Anti-inflammatory and profibrinolytic effect of insulin in acute ST-segment-elevation myocardial infarction.
(77/344)
BACKGROUND: The clinical benefits of insulin previously observed in acute ST-segment-elevation myocardial infarction (STEMI) may be partially explained by an anti-inflammatory effect. We assessed this potential effect of insulin in STEMI patients treated with fibrinolytics. METHODS AND RESULTS: Thirty-two patients receiving reteplase were randomly assigned infusions of either insulin at 2.5 U/h, dextrose, and potassium (GIK) or normal saline and potassium (C) for 48 hours. Plasma concentrations of high-sensitivity C-reactive protein (CRP), serum amyloid A (SAA), plasminogen activator inhibitor-1 (PAI-1), creatine kinase (CK), and CK-MB were measured at baseline and sequentially for 48 hours. Total p47phox protein in mononuclear cells was measured in a subgroup of 13 subjects. Baseline CRP and SAA were significantly increased (2- to 4-fold) at 24 and 48 hours in each group (P<0.01). However, in the insulin group, there was a significant (P<0.05) attenuation of the absolute rise in concentration of CRP and SAA from baseline. The absolute increase of CRP and SAA was reduced by 40% (CRP) and 50% (SAA) at 24 hours and at 48 hours compared with the control group. The absolute increase in PAI-1 from baseline and the percentage increase in p47phox over 48 hours were significantly (P<0.05) lower in the insulin-treated group. CK-MB peaked earlier and tended to be lower in insulin-treated subjects, especially in patients with inferior MI. CONCLUSIONS: Insulin has an anti-inflammatory and profibrinolytic effect in patients with acute MI. These effects may contribute to the clinical benefits of insulin in STEMI. (+info)
Differential expression of cardiac biomarkers by gender in patients with unstable angina/non-ST-elevation myocardial infarction: a TACTICS-TIMI 18 (Treat Angina with Aggrastat and determine Cost of Therapy with an Invasive or Conservative Strategy-Thrombolysis In Myocardial Infarction 18) substudy.
(78/344)
BACKGROUND: Diagnosis of coronary artery disease in women is more difficult because of lower specificity of symptoms and diagnostic accuracy of noninvasive testing. We sought to examine the relationship between gender and cardiac biomarkers in patients with unstable angina (UA)/non-ST-segment elevation myocardial infarction (NSTEMI). METHODS AND RESULTS: In the TACTICS-TIMI 18, OPUS-TIMI 16, and TIMI 11 studies, baseline samples were analyzed in the Thrombolysis In Myocardial Infarction (TIMI) biomarker core laboratory. We examined the relationship between gender and elevated biomarkers. Of 1865 patients from TACTICS-TIMI 18, 34% were women. Fewer women had elevated creatine kinase-MB or troponins, whereas more had elevated high-sensitivity C-reactive protein or brain natriuretic peptide. Presence of ST-segment deviation and TIMI risk scores were not significantly different. This pattern was confirmed in TIMI 11 and OPUS-TIMI 16. The prognostic value of the markers in TACTICS-TIMI 18 was similar in women and men. When a multimarker approach was examined, a greater proportion of high-risk women were identified. Marker-positive patients of both genders had improved outcome with an invasive strategy; however, marker-negative women appeared to have improved outcomes with a conservative strategy. CONCLUSIONS: In patients with UA/NSTEMI, there was a different pattern of presenting biomarkers. Men were more likely to have elevated creatine kinase-MB and troponins, whereas women were more likely to have elevated C-reactive protein and brain natriuretic peptide. This suggests that a multimarker approach may aid the initial risk assessment of UA/NSTEMI, especially in women. Further research is necessary to elucidate whether gender-related pathophysiological differences exist in presentation with acute coronary syndromes. (+info)
Resuscitation with 100% O(2) does not protect the myocardium in hypoxic newborn piglets.
(79/344)
BACKGROUND: Perinatal asphyxia is associated with cardiac dysfunction secondary to myocardial ischaemia. Cardiac troponin I (cTnI) is a marker of myocardial necrosis. Raised concentrations in the blood are related to perinatal asphyxia and increased morbidity. OBJECTIVE: To assess porcine myocardial damage from enzyme release during hypoxaemia induced global ischaemia, and subsequent resuscitation with ambient air or 100% O(2). To investigate whether CO(2) level during resuscitation influences myocardial damage. DESIGN: Newborn piglets (12-36 hours) were exposed to hypoxaemia by ventilation with 8% O(2) in nitrogen. When mean arterial blood pressure had fallen to 15 mm Hg, or base excess to < -20 mmol/l, the animals were randomly resuscitated by ventilation with either 21% O(2) (group A, n = 29) or 100% O(2) (group B, n = 29) for 30 minutes. Afterwards they were observed in ambient air for another 150 minutes. During resuscitation, the two groups were further divided into three subgroups with different CO(2) levels. ANALYSIS: Blood samples were analysed for cTnI, myoglobin, and creatine kinase-myocardial band (CK-MB) at baseline and at the end of the study. RESULTS: cTnI increased more than 10-fold (p < 0.001) in all the groups. Myoglobin and CK-MB doubled in concentration. CONCLUSION: The considerable increase in cTnI indicates seriously affected myocardium. Reoxygenation with 100% oxygen offered no biochemical benefit over ambient air. CK-MB and myoglobin were not reliable markers of myocardial damage. Normoventilation tended to produce better myocardial outcome than hyperventilation or hypoventilation. (+info)
Creatine kinase-MB elevation after percutaneous coronary intervention predicts adverse outcomes in patients with acute coronary syndromes.
(80/344)
AIM: To study the relationship between outcomes and peak creatine kinase (CK)-MB levels after percutaneous coronary intervention (PCI) in patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS). METHODS AND RESULTS: Peak CK-MB ratios (peak CK-MB level/upper limit of normal [ULN]) after PCI were analysed in 6164 patients with NSTE ACS from four randomized trials who underwent in-hospital PCI. We excluded 696 patients with elevated CK or CK-MB levels <24h before PCI; the primary analysis included 2384 of the remaining 5468 patients (43.6%) with CK-MB levels measured <==24h after PCI. The incidence of in-hospital heart failure (0.1%, 0.8%, 3.4%, 4.1%, and 6.1%; P<0.001), arrhythmias (0.8%, 1.9%, 6.9%, 4.1%, and 7.9%; P<0.001), cardiogenic shock (0.1%, 1.3%, 2.0%, 2.3%, and 2.6%; P=0.004), and mortality through 6 months (2.1%, 2.4%, 4.9%, 4.1%, and 5.7%, P=0.005) was increased with peak CK-MB ratios of 0-1, 1-3, 3-5, 5-10, and >10xULN, respectively. The continuous peak CK-MB ratio after PCI significantly predicted adjusted 6-month mortality (risk ratio, 1.06 per unit increase above ULN; 95% confidence interval, 1.01-1.11; P=0.017). CONCLUSIONS: Greater CK-MB elevation after PCI is independently associated with adverse outcomes in NSTE ACS. These results underscore the adverse implications of elevated CK-MB levels after PCI in this high-risk population. (+info)