Cardiac troponin I for risk stratification following percutaneous coronary artery intervention in acute coronary syndromes

Cord-Blood High-Sensitivity Troponin-I Reference Interval and Association with Early Neonatal Outcomes

OBJECTIVE

This study was aimed to establish a reference interval for high-sensitivity cardiac troponin I (hs-cTnI) in umbilical cord blood of infants and to assess its association with the risk of predetermined early neonatal outcomes in a high-acuity tertiary care hospital.

STUDY DESIGN

Umbilical cord-blood samples were collected and hs-cTnI was measured in all infants born between August 2015 and September 2015 at McMaster Children's Hospital (n = 256). Gestational age, birth weight, Apgar's scores, age in days at which feeding was established, neonatal intensive care unit (NICU) admission, and discharge in days after birth were recorded.

RESULTS

The 90th, 95th, and 99th percentiles for the term infant subcohort were 19.75, 41.45, and 166.30 ng/L, respectively. We observed decreased mean gestational ages and birth weights in both the 90th (37.7 weeks; 2,961.4 g) and 95th percentiles (37.1 weeks; 2,709.9 g) when compared with the remaining infants. Moreover, levels of hs-cTnI were significantly higher in infants with respiratory distress requiring intervention (p < 0.05), low birth weight infants (p < 0.01), preterm infants (p < 0.001), and those requiring NICU admission (p < 0.01). Multiple linear regression of the recorded demographic factors revealed prematurity (gestational age <35 weeks: coefficient 0.346 ± 0.160, p < 0.05; gestational age <37 weeks: coefficient 0.253 ± 0.105, p < 0.05) and male sex (coefficient 0.138 ± 0.047; p < 0.01) to be most predictive of log-hs-cTnI levels.

CONCLUSION

This study establishes the reference values for cord-blood hs-cTnI in infants at a tertiary care center. Premature and sick infants requiring NICU admission had significantly higher levels of hs-cTnI.

KEY POINTS

· Established the 90th, 95th, and 99th percentiles of neonatal cord-blood hs-cTnI in term infants as 19.75, 41.45, and 166.30 ng/L, respectively.. · Infants with hs-cTnI levels exceeding the 90th percentile had lower gestational ages and birth weights with higher rates of NICU admissions.. · Infants with respiratory distress or requiring NICU admission were found to have higher levels of hs-cTnI..

Bleeding following Coronary Surgery after Preoperative Low-Molecular-Weight Heparin

Low-molecular-weight heparin and acetyl salicylic acid have become an established treatment for unstable angina. A retrospective study on our database of one year was carried out to see what impact preoperative low-molecular-weight heparin versus none had on the postoperative course of 473 patients having coronary surgery exclusively. Apart from the fact that the low-molecular-weight heparin patients had a higher New York Heart Association classification and marginally more grafts, longer bypass and cross-clamp time, the preoperative characteristics and surgery of the two groups were similar. The low-molecular-weight heparin group had twice as many (9.7% versus 4.7%) re-operations for bleeding, 46% versus 26% had blood transfusion and 22.3% versus 12.6% plasma transfusion. The postoperative outcome was otherwise similar. Preoperative treatment of unstable angina with low-molecular-weight heparin carries a definite risk of postoperative bleeding. Although this study did not reveal any serious consequences, bleeding, transfusions and re-operations are associated with infections, wound healing problems and death. The indications and length of treatment with low-molecular-weight heparin in unstable angina patients have to be appropriate and the perioperative management of these patients has to address the bleeding tendency.

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.

Prognostic role of cardiac troponin I after percutaneous coronary intervention in stable coronary disease

OBJECTIVE

To assess the role of cardiac troponin I (cTnI) in predicting outcome after percutaneous coronary intervention (PCI).

METHODS AND RESULTS

cTnI was measured immediately before and at 6, 14, and 24 hours after PCI in 316 consecutive patients with stable symptoms and native coronary artery disease. The study end point was the occurrence of major adverse cardiac events (MACE) at 30 days and at 18 months after PCI: death, Q wave myocardial infarction (MI), or repeat revascularisation in hospital. Postprocedural cTnI increased in 31% of patients. The cumulative MACE rate at 18 months was 25% (17.7% due to repeat PCI procedures). There was a significant association between postprocedural cTnI increase and death, Q wave MI, or both (odds ratio (OR) 3.28, 95% confidence interval (CI) 1.7 to 6.4, p = 0.01). Post-PCI cTnI increase had a positive predictive value (PPV) for adverse events at 18 months of 0.47 and a negative predictive value (NPV) of 0.96 (OR 18.9, 95% CI 9.7 to 37, p < 0.0001). The presence of both a postprocedural cTnI rise and a procedural angiographic complication gave a PPV for adverse events of 0.69 and an NPV of 0.92 (OR 22.6, 95% CI 2.6 to 68.6, p = 0.0005).

CONCLUSIONS

cTnI increased post-procedurally in one third of this stable patient population undergoing elective PCI and was independently and significantly predictive of an increased risk of adverse events at 18 months, predominantly in the form of repeat PCI.

Myocardial protective effects of nicorandil during percutaneous coronary intervention in patients with unstable angina

BACKGROUND

The purpose of the study was to prospectively evaluate the protective effect of nicorandil during percutaneous coronary intervention (PCI) in patients with unstable angina (UAP).

METHODS AND RESULTS

Two hundred patients (61+/-10 year-old, male 143) diagnosed with UAP at an emergency medical center were randomly assigned to 2 groups: intravenous isosorbide dinitrate, Group I (n=100), or intravenous nicorandil, Group II (n=100). PCI was performed 12-48 h after infusion of each agent. Serum concentrations of creatine kinase-MB (CK-MB), cardiac troponin T (cTnT), and I (cTnI) were measured before and 6, 12, 24 h after PCI. Patients with non-coronary chest pain, requiring emergency coronary angiogram, temporary pacemaker or glycoprotein IIb/IIIa receptor blocker were excluded. PCI was successfully performed in 96 patients (Group I=54, 61.7+/-8.2 years, 32 males; Group II=42, 60.4+/-11.7 years, 27 males). No significant differences in clinical or coronary angiographic characteristics were observed between the 2 groups. The concentration of CK-MB was elevated in 9 patients (17%) of Group I and 6 (14%) of Group II, cTnT in 16 (30%), 6 (14%) and cTnI in 25 (46%), 9 (21%) after PCI. Elevation of any troponin was less frequent in Group II [28/54 (52%) vs 10/42 (24%) patients, p=0.01]. Major adverse coronary events during the 6-month clinical follow-up occurred in 9 (17%) of Group I and 5 patients of Group II (12%, p=NS). Follow-up echocardiography revealed lower left ventricular ejection fraction in Group I than in Group II (65.4+/-7.2% vs 71.0+/-6.7%, p=0.03).

CONCLUSION

Nicorandil has a myocardial protective effect during PCI in patients with UAP.

Reference values for cardiac troponins T and I in healthy neonates

OBJECTIVES

Cardiac troponins T (cTnT) and I (cTnI) are the most sensitive biochemical parameters in the detection of myocardial damage. In neonates, in utero exposure to tocolytic therapy results in detectable values of cardiac troponins after delivery. Additionally, some preliminary results suggest that the upper reference limits for healthy newborns are higher than those for adults but definitive reference limits for newborns are not available. Our objective was to determine those limits.

DESIGN AND METHODS

In this study we investigated the distribution of cTnT and cTnI in cord blood of 869 healthy newborns. cTnT was determined with the 3rd generation assay and cTnI with the Dade Behring assay on a Dimension RxL. For data analysis Student's t test and the Mann-Whitney U test were used.

RESULTS

Using the 99th percentile, the upper reference limit in healthy termed newborns was 0.097 microg/l for cTnT and 0.183 microg/l for cTnI. Compared to the adult values, the newborn upper limit was tripled for cTnT and doubled for cTnI. Statistically significant differences were found between males and females for cTnT and between natural childbirth and caesarean section for cTnI.

CONCLUSION

Healthy-termed newborns have a higher upper reference limit for both cTnT and cTnI compared to adults. This circumstance must be taken into account when interpreting slightly "elevated" cTnT and cTnI values in newborns.