Why all the struggle about CK-MB and PCI?

Triglyceride glucose index predicts in-hospital mortality in patients with ST-segment elevation myocardial infarction who underwent primary angiography

OBJECTIVES

To assess the correlation between triglyceride glucose (TyG) index and in-hospital mortality in patients with ST-segment elevation myocardial infarction (STEMI).

METHODS

A total of 2190 patients with STEMI who underwent primary angiography within 12 h from symptom onset were selected from the prospective, nationwide, multicenter CAMI registry. TyG index was calculated with the formula: Ln [fasting triglycerides (mmol/L) × fasting glucose (mmol/L)/2]. Patients were divided into three groups according to the tertiles of TyG index. The primary endpoint was in-hospital mortality.

RESULTS

Overall, 46 patients died during hospitalization, in-hospital mortality was 1.5%, 2.2%, 2.6% for tertile 1, tertile 2, and tertile 3, respectively. However, TyG index was not significantly correlated with in-hospital mortality in single-variable logistic regression analysis. Nonetheless, after adjusting for age and sex, TyG index was significantly associated with higher mortality when regarded as a continuous variable (adjusted OR = 1.75, 95% CI: 1.16-2.63) or categorical variable (tertile 3 vs. tertile 1: adjusted OR = 2.50, 95% CI: 1.14-5.49). Furthermore, TyG index, either as a continuous variable (adjusted OR = 2.54, 95% CI: 1.42-4.54) or categorical variable (tertile 3 vs. tertile 1: adjusted OR = 3.57, 95% CI: 1.24-10.29), was an independent predictor of in-hospital mortality after adjusting for multiple confounders in multivariable logistic regression analysis. In subgroup analysis, the prognostic effect of high TyG index was more significant in patients with body mass index < 18.5 kg/m² (P _interaction = 0.006).

CONCLUSIONS

This study showed that TyG index was positively correlated with in-hospital mortality in STEMI patients who underwent primary angiography, especially in underweight patients.

Procedural myocardial injury, infarction and mortality in patients undergoing elective PCI: a pooled analysis of patient-level data

AIMS

The prognostic importance of cardiac procedural myocardial injury and myocardial infarction (MI) in chronic coronary syndrome (CCS) patients undergoing elective percutaneous coronary intervention (PCI) is still debated.

METHODS AND RESULTS

We analysed individual data of 9081 patients undergoing elective PCI with normal pre-PCI baseline cardiac troponin (cTn) levels. Multivariate models evaluated the association between post-PCI elevations in cTn and 1-year mortality, while an interval analysis evaluated the impact of the size of the myocardial injury on mortality. Our analysis was performed in the overall population and also according to the type of cTn used [52.0% had high-sensitivity cTn (hs-cTn)]. Procedural myocardial injury, as defined by the Fourth Universal Definition of MI (UDMI) [post-PCI cTn elevation ≥1 × 99th percentile upper reference limit (URL)], occurred in 52.8% of patients and was not associated with 1-year mortality [adj odds ratio (OR), 1.35, 95% confidence interval (CI) (0.84-1.77), P = 0.21]. The association between post-PCI cTn elevation and 1-year mortality was significant starting ≥3 × 99th percentile URL. Major myocardial injury defined by post-PCI ≥5 × 99th percentile URL occurred in 18.2% of patients and was associated with a two-fold increase in the adjusted odds of 1-year mortality [2.29, 95% CI (1.32-3.97), P = 0.004]. In the subset of patients for whom periprocedural evidence of ischaemia was collected (n = 2316), Type 4a MI defined by the Fourth UDMI occurred in 12.7% of patients and was strongly associated with 1-year mortality [adj OR 3.21, 95% CI (1.42-7.27), P = 0.005]. We also present our results according to the type of troponin used (hs-cTn or conventional troponin).

CONCLUSION

Our analysis has demonstrated that in CCS patients with normal baseline cTn levels, the post-PCI cTn elevation of ≥5 × 99th percentile URL used to define Type 4a MI is associated with 1-year mortality and could be used to detect 'major' procedural myocardial injury in the absence of procedural complications or evidence of new myocardial ischaemia.

Reducing redundant creatine kinase testing in cardiac injury

Background

Creatine kinase (CK) testing in the setting of suspected cardiac injury is commonly performed yet rarely provides clinical value beyond troponin testing. We sought to evaluate and reduce CK testing coupled with troponin testing by 50% or greater.

Methods

We performed root cause analysis to study prevailing processes and patterns of CK testing. We developed new institutional guidelines, removed CK from high-volume paper and electronic order bundles and conducted academic detailing for departments with highest ordering frequency. We evaluated consecutive patients at Sunnybrook Health Sciences Centre between 1 January 2018 and 31 March 2020 who had either a CK or troponin level measured. We prespecified successful implementation as a reduction of 50% in total CK orders and a decrease in the ratio of CK-to-troponin tests to one-third or less. We retained additional data beyond our study period to assess for sustained reductions in testing.

Results

Total CK tests decreased over the study period from 3963 to 2111 per month, amounting to a 46.7% reduction (95% CI 33.2 to 60.2; p<0.001) equalling 61 fewer tests per hospital day. Troponin testing did not significantly change during the intervention. Ratio of CK-to-troponin tests decreased from 0.91 to 0.49 (p<0.001). The reduction coincided with changes to order-sets, was observed across all clinical units and was sustained during additional months beyond the study period. These reductions in testing resulted in a projected annual cost savings of C$28 446.

Conclusions

We demonstrate that a low-cost and feasible quality improvement initiative may lead to significant reduction in unnecessary CK testing and substantial savings in healthcare costs for patients with suspected cardiac injury.

Identification of patients at higher risk for myocardial injury following elective coronary artery intervention

OBJECTIVES

To evaluate myocardial injury and infarction (MI) following elective percutaneous coronary intervention (PCI).

BACKGROUND

The substantially higher analytical power of high-sensitivity troponin (hsTn) assays allows detection of minor cardiac troponin (cTn) levels, which may be useful in monitoring myocardial injury and guiding therapies.

METHODS

Serial hsTnT measurements were conducted in patients undergoing elective PCI and were related to the extent of coronary artery disease (CAD) as reflected by the SYNTAX score risk categories and American College of Cardiology/American Heart Association classification of coronary lesions. Myocardial injury and MI were diagnosed according to the second and third versions of universal MI definition.

RESULTS

The study population consisted of 530 patients, who were grouped into low (41.3%), intermediate (35.4%), and high (23.3%) SYNTAX risk categories. The treated coronary lesions were classified into A 7.8%, B1 24.1%, B2 21.1%, C1 24.6%, and C2 22.4%. Postprocedural hsTnT increases correlated significantly with the complexity of treated coronary lesions (p < .05) and CAD magnitude (p < .05). Rates of MI type 4a according to the second and third MI definition criteria were 98 (27.5%) and 15 (4.2%) cases in patients with normal baseline hsTnT values (N = 357, 67.4%), as well as 137 (79.2%) and 27 (15.6%) cases in those with elevated baseline hsTnT values (N = 173, 32.6%), respectively.

CONCLUSIONS

After elective PCI, cTn releases correlate significantly with lesion complexity and CAD extent. Use of hsTnT assay enables precise monitoring of PCI-related myocardial injury and may identify patients at higher risk for ischemic events, who may benefit from potent platelet inhibition, which needs to be investigated in randomized trials.

Potential impacts of high-sensitivity creatine kinase-MB on long-term clinical outcomes in patients with stable coronary heart disease

This study aimed to investigate the prognostic value of high-sensitivity creatine kinase-myocardial band or fraction (hsCK-MB) in comparison with other well-established biomarkers including heart type-fatty acid binding protein (H-FABP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) in patients with stable coronary heart disease (SCHD). A total of 1,785 patients were enrolled and followed for 36 months. The primary outcome was all-cause mortality. The secondary outcomes included cardiovascular (CV) death, acute myocardial infarction (AMI), angina-related hospitalizations, and hospitalizations for heart failure. The all-cause mortality rate was significantly higher in the high hsCK-MB group compared to the low hsCK-MB group (4.64% vs. 1.88%, p = 0.0026). After adjusting for baseline covariates, there were no significant differences for the secondary outcomes. H-FABP (≥4.226 ng/mL) was the best predictor for all-cause mortality (HR = 2.68, 95% CI = 1.28-5.62, p = 0.009) and CV death (HR = 6.84, 95% CI = 1.89-22.14, p = 0.003). The high NT-proBNP group had a higher AMI-related hospitalization rate (HR = 1.91, 95% CI = 1.00-3.65, p = 0.05). Neither the addition of hsCK-MB to any other markers nor combinations of the three markers improved the prognostic significance of CV outcomes. In conclusion, hsCK-MB was an independent predictor for all-cause mortality but not CV outcomes in patients with SCHD. Combination of hsCK-MB, H-FABP and NT-proBNP failed to improve the prognostic power for all-cause mortality or CV outcomes.

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

BACKGROUND

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

CONTENT

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

SUMMARY

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

Incidence and impact on prognosis of peri-procedural myocardial infarction in 2760 elective patients with stable angina pectoris in a historical prospective follow-up study

BACKGROUND

The clinical significance of myocardial infarction related to treatment with percutaneous coronary intervention (PCI) has been subject of great discussion. This subject has been studied for many years using different definitions of peri-procedural myocardial infarction and different biomarkers, the results have varied greatly depending on methods and time of the study. This study was to determine the incidence and prognostic significance of elevated cardiac biomarkers after elective PCI in patients with stable angina pectoris using the current cut-off set by the Third Universal Definition of Myocardial Infarction and current biomarkers.

METHODS

We performed a historical prospective follow-up study of all patients with stable angina pectoris who underwent elective PCI at Aalborg University Hospital, Denmark from January 1(st) 2000 to December 31(st) 2012. We stratified patients according to peak post-PCI troponin T (cTnT) and Creatine Kinase MB mass (CK-MBmass).

RESULTS

Follow-up for time to all-cause mortality was mean 5.8 years and total 15,891 years and mean 3.7 years and total 10,160 years for the combined endpoint of all-cause mortality and new onset heart failure. During the follow up period 399 of 2760 patients died (14.5 %) and 1095 (39.7 %) suffered the combined endpoint. Post-PCI concentration of cTnT and CK-MBmass was elevated above the defined cut-off in 419 patients (15.2 %) and 113 patients (4.1 %) respectively. There was no statistically significant difference between the groups in stratified analysis of the hazard rates by time regarding all-cause mortality for cTnT nor CK-MBmass. Regarding the combined endpoint the results were ambiguous. The results were unchanged in multivariable analyses that included age and gender.

CONCLUSION

The incidence of elevated biomarkers after elective PCI in patients with stable angina pectoris using the defined cut-off (>5 x URL) was 15.2 % using cTnT and 4.1 % using CK-MBmass. The independent prognostic value for both cardiac biomarkers of any cut-off showed no statistical significance for all-cause mortality, whereas the combined endpoint (all-cause mortality or new-onset heart failure) were ambiguous in both short- and long-term follow-up.

Incidence and Predictors of Cardiomyocyte Injury in Elective Coronary Angiography

OBJECTIVE

Coronary angiography is considered to be a safe tool for the evaluation of coronary artery disease and performed in approximately 12 million patients each year worldwide. The aim of our study was to investigate the frequency and predictors of cardiomyocyte injury in patients undergoing elective coronary angiography.

METHODS

A total of 749 consecutive patients who were scheduled to undergo elective coronary angiography were prospectively analyzed. High-sensitivity cardiac troponin T concentrations were measured both before and after elective coronary angiography (without intervention). Acute cardiomyocyte injury was predefined as an absolute increase in high-sensitivity cardiac troponin T of at least 7 ng/L (if also fulfilling a relative change of >20%).

RESULTS

Acute cardiomyocyte injury was observed in 101 patients (13.5%, 95% confidence interval [CI], 11.1-16.2). It was independently associated with aortic valve stenosis (odds ratio [OR], 5.4; 95% CI, 3.0-9.8; P <.001), age (OR, 1.05; 95% CI, 1.02-1.08; P <.001), female sex (OR, 3.5; 95% CI, 1.8-6.8; P <.001), contrast volume (OR, 1.006; 95% CI, 1.001-1.012; P = .019 per 10 mL of contrast volume), documented cardiomyopathy (OR, 2.5; 95% CI, 1.0-6.0; P = .045), and mitral regurgitation (OR, 2.3; CI, 1.0-4.9; P = .033). In contrast, operator experience and extent of coronary artery disease were not found to be associated with acute cardiomyocyte injury.

CONCLUSIONS

Cardiomyocyte injury accompanies elective coronary angiography in 1 of 8 patients. Sex, age, contrast agent volume, and ventricular disease, rather than the extent of coronary artery disease, independently predict cardiomyocyte injury. Further research aiming to reduce the incidence of cardiomyocyte injury seems warranted.

Recent advances in the diagnosis and treatment of acute myocardial infarction

The Third Universal Definition of Myocardial Infarction (MI) requires cardiac myocyte necrosis with an increase and/or a decrease in a patient’s plasma of cardiac troponin (cTn) with at least one cTn measurement greater than the 99^th percentile of the upper normal reference limit during: (1) symptoms of myocardial ischemia; (2) new significant electrocardiogram (ECG) ST-segment/T-wave changes or left bundle branch block; (3) the development of pathological ECG Q waves; (4) new loss of viable myocardium or regional wall motion abnormality identified by an imaging procedure; or (5) identification of intracoronary thrombus by angiography or autopsy. Myocardial infarction, when diagnosed, is now classified into five types. Detection of a rise and a fall of troponin are essential to the diagnosis of acute MI. However, high sensitivity troponin assays can increase the sensitivity but decrease the specificity of MI diagnosis. The ECG remains a cornerstone in the diagnosis of MI and should be frequently repeated, especially if the initial ECG is not diagnostic of MI.

There have been significant advances in adjunctive pharmacotherapy, procedural techniques and stent technology in the treatment of patients with MIs. The routine use of antiplatelet agents such as clopidogrel, prasugrel or ticagrelor, in addition to aspirin, reduces patient morbidity and mortality. Percutaneous coronary intervention (PCI) in a timely manner is the primary treatment of patients with acute ST segment elevation MI. Drug eluting coronary stents are safe and beneficial with primary coronary intervention. Treatment with direct thrombin inhibitors during PCI is non-inferior to unfractionated heparin and glycoprotein IIb/IIIa receptor antagonists and is associated with a significant reduction in bleeding. The intra-coronary use of a glycoprotein IIb/IIIa antagonist can reduce infarct size. Pre- and post-conditioning techniques can provide additional cardioprotection. However, the incidence and mortality due to MI continues to be high despite all these recent advances. The initial ten year experience with autologous human bone marrow mononuclear cells (BMCs) in patients with MI showed modest but significant increases in left ventricular (LV) ejection fraction, decreases in LV end-systolic volume and reductions in MI size. These studies established that the intramyocardial or intracoronary administration of stem cells is safe. However, many of these studies consisted of small numbers of patients who were not randomized to BMCs or placebo. The recent LateTime, Time, and Swiss Multicenter Trials in patients with MI did not demonstrate significant improvement in patient LV ejection fraction with BMCs in comparison with placebo. Possible explanations include the early use of PCI in these patients, heterogeneous BMC populations which died prematurely from patients with chronic ischemic disease, red blood cell contamination which decreases BMC renewal, and heparin which decreases BMC migration. In contrast, cardiac stem cells from the right atrial appendage and ventricular septum and apex in the SCIPIO and CADUCEUS Trials appear to reduce patient MI size and increase viable myocardium. Additional clinical studies with cardiac stem cells are in progress.

Impact on prognosis of periprocedural myocardial infarction after percutaneous coronary intervention

INTRODUCTION

Different definitions of periprocedural myocardial infarction (MI) after percutaneous coronary intervention (PCI) have been provided, but their impact on prognosis remains to be determined.

METHODS

Procedural data from consecutive patients undergoing PCI from 2009 to 2011 were revised to adjudicate diagnosis of periprocedural MI according to CK-MB increase (>3 × URL and >5 × URL), to troponin increase (>3 × 99th percentile URL and >5 × 99th percentile URL) and to recent 2012 Task Force and Society for Cardiovascular Angiography and Interventions (SCAI) definitions. Major adverse cardiovascular events (MACE) was the primary end-point.

RESULTS

Seven hundred twelve patients were enrolled; after 771 days, 115 (16.7%) patients experienced MACE. One hundred ninety patients were diagnosed with a periprocedural MI defined as elevation of troponin >5 × 99th percentile of URL. When adjudicating 2012 Task Force definition on these patients, 46 were excluded and 1.4% of them experienced a MACE and 0.3% died, while among 144 with periprocedural MI, 2.9% reported a MACE and 1.3% died. After appraisal of SCAI definition, 176 patients were excluded, 3.8% of them with a MACE and 1.4% died, and for those with periprocedural MI, 0.5% experienced a MACE and 0.1% died. Similar low performance was appraised after reclassification of patients from more than 3 of upper limit of CK-MB and of troponin. At multivariate analysis, none of these definitions related to adverse events.

CONCLUSION

Periprocedural MI represents a frequent complication for patients undergoing PCI. All present definitions share a still not satisfactory discrimination between patients with and without adverse events at follow-up, stressing the need for more accurate definitions.

Creatine kinase-MB: the journey to obsolescence

OBJECTIVES

To evaluate the clinical utility of and demand for the creatine kinase (CK)-MB assay.

METHODS

We examined the number of CK-MB tests from 2007 through 2013 while we progressively deemphasized their use. We first removed CK-MB from the acute coronary syndrome (ACS) panel and then from the main menu and observed the demand for the test. We also reviewed patient medical records to assess the appropriateness of its use.

RESULTS

After removing CK-MB from the ACS panel, the test volume dropped from around 12,000 per year to about 150 per year. In reviewing the records of 171 patients who had CK-MB determination done over a 28-month period, we discovered that CK-MB contributed to the diagnosis in only one patient, although it was not essential. Since removing CK-MB from the laboratory menu, two CK-MB tests were ordered in 4 months, and neither added value.

CONCLUSIONS

CK-MB determinations do not add value to information available from the troponin assay and can be safely removed from the laboratory menu.