Abnormal release of cardiac biomarkers in the presence of myocardial oedema evaluated by cardiac magnetic resonance after uncomplicated revascularization procedures

AIMS

To analyse the association of myocardial oedema (ME), observed as high T2 signal intensity (HT2) in cardiac magnetic resonance imaging, with the release of cardiac biomarkers, ventricular ejection, and clinical outcomes after revascularization.

METHODS AND RESULTS

Patients with stable coronary artery disease with the indication for revascularization were included. Biomarker levels [troponin I (cTnI) and creatine kinase MB (CK-MB)] and T2-weighted and late gadolinium enhancement (LGE) images were obtained before and after the percutaneous or surgical revascularization procedures. The association of HT2 with the levels of biomarkers, with and without LGE, evolution of left ventricular ejection fraction (LVEF), and 5-year clinical outcomes were assessed. A total of 196 patients were divided into 2 groups: Group 1 (HT2, 40) and Group 2 (no HT2, 156). Both peak cTnI (8.9 and 1.6 ng/mL) and peak CK-MB values (44.7 and 12.1 ng/mL) were significantly higher in Group 1. Based on the presence of new LGE, patients were stratified into Groups A (no HT2/LGE, 149), B (HT2, 9), C (LGE, 7), and D (both HT2/LGE, 31). The peak cTnI and CK-MB values were 1.5 and 12.0, 5.4 and 44.7, 5.0 and 18.3, and 9.8 and 42.8 ng/mL in Groups A, B, C, and D, respectively, and were significantly different. The average LVEF decreased by 4.4% in Group 1 and increased by 2.2% in Group 2 (P = 0.057).

CONCLUSION

ME after revascularization procedures was associated with increased release of cardiac necrosis biomarkers, and a trend towards a difference in LVEF, indicating a role of ME in cardiac injury after interventions.

Chronic troponin elevation assessed by myocardial T1 mapping in patients with stable coronary artery disease

BACKGROUND

Cardiac troponin detected with sensitive assays can be chronically elevated, in the absence of unstable coronary syndromes. In patients with chronic coronary artery disease, clinically silent ischemic episodes may cause chronic troponin release. T1 mapping is a cardiovascular magnetic resonance technique useful in quantitative cardiac tissue characterization. We selected patients with anatomically and functionally normal hearts to investigate associations between chronic troponin release and myocardial tissue characteristics assessed by T1 mapping.

METHODS

We investigated the relationship between cardiac troponin I concentrations and cardiovascular magnetic resonance T1 mapping parameters in patients with stable coronary artery disease enrolled in MASS V study before elective revascularization. Participants had no previous myocardial infarction, negative late gadolinium enhancement, normal left ventricular function, chamber dimensions and wall thickness.

RESULTS

A total of 56 patients were analyzed in troponin tertiles: nativeT1 and extracellular volume (ECV) values (expressed as means ± standard deviations) increased across tertiles: nativeT1 (1006 ± 27 ms vs 1016 ± 27 ms vs 1034 ± 37 ms, ptrend = 0.006) and ECV (22 ± 3% vs 23 ± 1.9% vs 25 ± 3%, ptrend = 0.007). Cardiac troponin I concentrations correlated with native T1(R = 0.33, P = .012) and ECV (R = 0.3, P = .025), and were independently associated with nativeT1 (P = .049) and ventricular mass index (P = .041) in multivariable analysis.

CONCLUSION

In patients with chronic coronary artery disease and structurally normal hearts, troponin I concentrations correlated with T1 mapping parameters, suggesting that diffuse edema or fibrosis scattered in normal myocardium might be associated with chronic troponin release.

Abnormal elevation of myocardial necrosis biomarkers after coronary artery bypass grafting without established myocardial infarction assessed by cardiac magnetic resonance

BACKGROUND

The diagnosis of peri-procedural myocardial infarction is complex, especially after the emergence of high-sensitivity markers of myocardial necrosis.

METHODS

In this study, patients with normal baseline cardiac biomarkers and formal indication for elective on-pump coronary bypass surgery were evaluated. Electrocardiograms, cardiac biomarkers, and cardiac magnetic resonance imaging with late gadolinium enhancement were performed before and after procedures. Myocardial infarction was defined as more than ten times the upper reference limit of the 99th percentile for troponin I and for creatine kinase isoform (CK-MB) and by the findings of new late gadolinium enhancement on cardiac magnetic resonance. We assessed the release of cardiac biomarkers in patients with no evidence of myocardial infarction on cardiac magnetic resonance.

RESULTS

Of 75 patients referred for on-pump coronary bypass surgery, 54 (100%) did not have evidence of myocardial infarction on cardiac magnetic resonance. However, all had a peak troponin I above the 99th percentile; 52 (96%) had an elevation 10 times higher than the 99th percentile. Regarding CK-MB, 54 (100%) patients had a peak CK-MB above the 99th percentile limit, and only 13 (24%) had an elevation greater than 10 times the 99th percentile. The median value of troponin I peak was 3.15 (1.2 to 3.9) ng/mL, which represented 78.7 times the 99th percentile.

CONCLUSION

In this study, different from CK-MB findings, troponin was significantly increased in the absence of myocardial infarction on cardiac magnetic resonance. Thus, CK-MB was more accurate than troponin I for excluding procedure-related myocardial infarction. These data suggest a higher troponin cutoff for the diagnosis of coronary bypass surgery related myocardial infarction.

CLINICAL TRIAL REGISTRATION

http://www.isrctn.com/ISRCTN09454308 . Registered 08 May 2012.

Significant elevation of biomarkers of myocardial necrosis after coronary artery bypass grafting without myocardial infarction established assessed by cardiac magnetic resonance

The release of myocardial necrosis biomarkers after off-pump coronary artery bypass grafting (OPCAB) frequently occurs. However, the correlation between biomarker release and the diagnosis of procedure-related myocardial infarction (MI) (type 5) has been controversial. This study aimed to evaluate the amount and pattern of cardiac biomarker release after elective OPCAB in patients without evidence of a new MI on cardiac magnetic resonance (CMR) imaging with late gadolinium enhancement (LGE).Patients with normal baseline cardiac biomarkers referred for elective OPCAB were prospectively included. CMR with LGE was performed in all patients before and after interventions. Measurements of troponin I (cTnI) and creatine kinase MB fraction (CK-MB) were systematically performed before and after the procedure. Patients with new LGE on the postprocedure CMR were excluded.All of the 53 patients without CMR evidence of a procedure-related MI after OPCAB exhibited a cTnI elevation peak above the 99th percentile. In 48 (91%), the peak value was >10 times this threshold. However, 41 (77%) had a CK-MB peak above the limit of the 99th percentile, and this peak was >10 times the 99th percentile in only 7 patients (13%). The median peak release of cTnI was 0.290 (0.8-3.7) ng/mL, which is 50-fold higher than the 99th percentile.In contrast with CK-MB, considerable cTnI release often occurs after an elective OPCAB procedure, despite the absence of new LGE on CMR.

Accuracy of Myocardial Biomarkers in the Diagnosis of Myocardial Infarction After Revascularization as Assessed by Cardiac Resonance: The Medicine, Angioplasty, Surgery Study V (MASS-V) Trial

BACKGROUND

The lack of a correlation between myocardial necrosis biomarkers and electrocardiographic abnormalities after revascularization procedures has resulted in a change in the myocardial infarction (MI) definition.

METHODS

Patients with stable multivessel disease who underwent percutaneous or surgical revascularization were included. Electrocardiograms and concentrations of high-sensitive cardiac troponin I (cTnI) and creatine kinase (CK)-MB were assessed before and after procedures. Cardiac magnetic resonance and late gadolinium enhancement were performed before and after procedures. MI was defined as more than five times the 99th percentile upper reference limit for cTnI and 10 times for CK-MB in percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG), respectively, and new late gadolinium enhancement for cardiac magnetic resonance.

RESULTS

Of the 202 patients studied, 69 (34.1%) underwent on-pump CABG, 67 (33.2%) off-pump CABG, and 66 (32.7%) PCI. The receiver operating characteristic curve showed the accuracy of cTnI for on-pump CABG, off-pump CABG, and PCI patients was 21.7%, 28.3%, and 52.4% and for CK-MB was 72.5%, 81.2%, and 90.5%, respectively. The specificity of cTnI was 3.6%, 9.4%, and 42.1% and of CK-MB was 73.2%, 86.8%, and 96.4%, respectively. Sensitivity of cTnI was 100%, 100%, and 100% and of CK-MB was 69.2%, 64.3%, and 44.4%, respectively. The best cutoff of cTnI for on-pump CABG, off-pump CABG, and PCI was 6.5 ng/mL, 4.5 ng/mL, and 4.5 ng/mL (162.5, 112.5, and 112.5 times the 99th percentile upper reference limit) and of CK-MB was 37.5 ng/mL, 22.5 ng/mL, and 11.5 ng/mL (8.5, 5.1, and 2.6 times the 99th percentile upper reference limit), respectively.

CONCLUSIONS

Compared with cardiac magnetic resonance, CK-MB was more accurate than cTnI for diagnosing MI. These data suggest a higher troponin cutoff for the diagnosis of procedure-related MI.

Hypotheses, rationale, design, and methods for prognostic evaluation of cardiac biomarker elevation after percutaneous and surgical revascularization in the absence of manifest myocardial infarction. A comparative analysis of biomarkers and cardiac magnetic resonance. The MASS-V Trial

BACKGROUND

Although the release of cardiac biomarkers after percutaneous (PCI) or surgical revascularization (CABG) is common, its prognostic significance is not known. Questions remain about the mechanisms and degree of correlation between the release, the volume of myocardial tissue loss, and the long-term significance. Delayed-enhancement of cardiac magnetic resonance (CMR) consistently quantifies areas of irreversible myocardial injury. To investigate the quantitative relationship between irreversible injury and cardiac biomarkers, we will evaluate the extent of irreversible injury in patients undergoing PCI and CABG and relate it to postprocedural modifications in cardiac biomarkers and long-term prognosis.

METHODS/DESIGN

The study will include 150 patients with multivessel coronary artery disease (CAD) with left ventricle ejection fraction (LVEF) and a formal indication for CABG; 50 patients will undergo CABG with cardiopulmonary bypass (CPB); 50 patients with the same arterial and ventricular condition indicated for myocardial revascularization will undergo CABG without CPB; and another 50 patients with CAD and preserved ventricular function will undergo PCI using stents. All patients will undergo CMR before and after surgery or PCI. We will also evaluate the release of cardiac markers of necrosis immediately before and after each procedure. Primary outcome considered is overall death in a 5-year follow-up. Secondary outcomes are levels of CK-MB isoenzyme and I-Troponin in association with presence of myocardial fibrosis and systolic left ventricle dysfunction assessed by CMR.

DISCUSSION

The MASS-V Trial aims to establish reliable values for parameters of enzyme markers of myocardial necrosis in the absence of manifest myocardial infarction after mechanical interventions. The establishments of these indices have diagnostic value and clinical prognosis and therefore require relevant and different therapeutic measures. In daily practice, the inappropriate use of these necrosis markers has led to misdiagnosis and therefore wrong treatment. The appearance of a more sensitive tool such as CMR provides an unprecedented diagnostic accuracy of myocardial damage when correlated with necrosis enzyme markers. We aim to correlate laboratory data with imaging, thereby establishing more refined data on the presence or absence of irreversible myocardial injury after the procedure, either percutaneous or surgical, and this, with or without the use of cardiopulmonary bypass.

VP4 and VP7 genotyping by reverse transcription-PCR of human rotavirus in mexican children with acute diarrhea

Dual typing (VP4 and VP7) of rotavirus obtained from 257 Mexican children during three epidemiological seasons was performed by reverse transcription-PCR. The P1G1 genotype was the most prevalent (40%), followed by P1G3 (19%) and P2G2 (16%). Thirty-one specimens (12%) presented mixed infections, while some genotypes were not found. This is the first dual typing of isolates from diarrhea cases in Mexico.