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Abstract Funding Acknowledgements Type of funding sources: Private hospital(s). Main funding source(s): Mayo Clinic Department of Laboratory Medicine and Pathology. Background Elevated lipoprotein(a) [Lp(a)] is associated with increased risk for atherosclerotic cardiovascular disease (ASCVD). Treatment of patients with elevated Lp(a) usually includes marked reduction in low density lipoprotein cholesterol (LDL-C). However, there are uncertainties about whether all increases in Lp(a) are equivalent in there risk relationship. Purpose The aim of this investigation was to risk stratify patients with elevated Lp(a) mass [Lp(a)-M] based on Lp(a) cholesterol (Lp(a)-C) measurements. We assessed coronary artery disease (CAD) by coronary angiogram and major adverse cardiac events (MACE) in a cohort of patients with elevated Lp(a) mass (≥30mg/dL) over a 15 year followup. Methods Electrophoretic and immunologic assays were used to measure Lp(a)-C and Lp(a)-M, respectively. Univariate and multivariate logistic regression analysis was employed to test for association between Lp(a) and CAD in a cohort patients with elevated Lp(a)-M (≥30mg/dL). The relationship between Lp(a) and time to major cardiac events was evaluated using cox regression analysis. Receiver operator curve (ROC) analyses were used to identify optimal cutoff values for Lp(a)-M and C for predicting CAD in our model. Results We analyzed 179 patients with elevated Lp(a)-M. Cutoff values of 3.3mg/dL for Lp(a)-C and 42.1mg/dL for Lp(a)-M optimally predicted CAD in an ROC analysis. Of these patients, 84 were found to have Lp(a)-C < 3.3mg/dL (low Lp(a)-C), while 95 patients had Lp(a)-C levels ≥ 3.3mg/dL (high Lp(a)-C). High Lp(a)-C was associated with CAD identified on coronary angiography in univariate (OR = 2.17, 95% CI = 1.18 – 4.00, p = 0.013) and multivariate (OR = 3.36, 95% CI = 1.64 – 6.89, p < 0.001) models controlling for traditional risk factors. In univariate analyses high Lp(a)-C was also associated with MACE (HR = 2.38, 95% CI = 1.19 – 4.75, p = 0.01) while Lp(a)-M ≥ 42.1mg/dL (high Lp(a)-M) was not (HR = 1.68, 95% CI = 0.82 – 3.44, p = 0.15) (Table 1, Figure 1). Lp(a)-C remained significantly correlated with MACE after adjusting for traditional risk factors. When included in a model together, Lp(a)-C maintained its significance while Lp(a)-M failed to predict MACE, indicating that Lp(a)-C is a stronger predictor of MACE than Lp(a)-M. Conclusion This study demonstrates that patients with elevated Lp(a)-M and high Lp(a)-C are approximately 2.5 times more likely to encounter MACE over time when compared to patients with elevated Lp(a)-M and low Lp(a)-C. Our investigation suggests that Lp(a)-C can be used to risk stratify patients with elevated Lp(a)-M and identify those at higher risk.

Background The association between growth differentiation factor-15 concentrations and cardiovascular disease has been well described. The study hypothesis was that growth differentiation factor-15 may help cardiac risk stratification in noncardiac surgical patients, in addition to clinical evaluation. Methods The objective of the study was to determine whether preoperative serum growth differentiation factor-15 is associated with the composite primary outcome of myocardial injury after noncardiac surgery and vascular death at 30 days and can improve cardiac risk prediction in noncardiac surgery. This is a prospective cohort study of patients 45 yr or older having major noncardiac surgery. The association between preoperative growth differentiation factor-15 and the primary outcome was determined after adjusting for the Revised Cardiac Risk Index. Preoperative N-terminal-pro hormone brain natriuretic peptide was also added to compare predictive performance with growth differentiation factor-15. Results Between October 27, 2008, and October 30, 2013, a total of 5,238 patients were included who had preoperative growth differentiation factor-15 measured (median, 1,325; interquartile range, 880 to 2,132 pg/ml). The risk of myocardial injury after noncardiac surgery and vascular death was 99 of 1,705 (5.8%) for growth differentiation factor-15 less than 1,000 pg/ml, 161 of 1,332 (12.1%) for growth differentiation factor-15 1,000 to less than 1,500 pg/ml, 302 of 1476 (20.5%) for growth differentiation factor-15 1,500 to less than 3,000 pg/ml, and 247 of 725 (34.1%) for growth differentiation factor-15 concentrations 3,000 pg/ml or greater. Compared to patients who had growth differentiation factor-15 concentrations less than 1,000 pg/ml, the corresponding adjusted hazard ratio for each growth differentiation factor-15 category was 1.93 (95% CI, 1.50 to 2.48), 3.04 (95% CI, 2.41 to 3.84), and 4.8 (95% CI, 3.76 to 6.14), respectively. The addition of growth differentiation factor-15 improved cardiac risk classification by 30.1% (301 per 1,000 patients) compared to Revised Cardiac Risk Index alone. It also provided additional risk classification beyond the combination of preoperative N-terminal-pro hormone brain natriuretic peptide and Revised Cardiac Risk Index (16.1%; 161 per 1,000 patients). Conclusions Growth differentiation factor-15 is strongly associated with 30-day risk of major cardiovascular events and significantly improved cardiac risk prediction in patients undergoing noncardiac surgery. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

ImportanceAnthracycline-containing regimens are highly effective for diffuse large B-cell lymphoma (DLBCL); however, patients with preexisting heart failure (HF) may be less likely to receive anthracyclines and may be at higher risk of lymphoma mortality.ObjectiveTo assess the prevalence of preexisting HF in older patients with DLBCL and its association with treatment patterns and outcomes.Design, Setting, and ParticipantsThis longitudinal cohort study used data from the Surveillance, Epidemiology, and End Results (SEER)–Medicare registry from 1999 to 2016. The SEER registry is a system of population-based cancer registries, capturing more than 25% of the US population. Linkage to Medicare offers additional information from billing claims. This study included individuals 65 years and older with newly diagnosed DLBCL from 2000 to 2015 with Medicare Part A or B continuously in the year prior to lymphoma diagnosis. Data were analyzed from September 2020 to December 2022.ExposuresPreexisting HF in the year prior to DLBCL diagnosis ascertained from billing codes required one of the following: (1) 1 primary inpatient discharge diagnosis, (2) 2 outpatient diagnoses, (3) 3 secondary inpatient discharge diagnoses, (4) 3 emergency department diagnoses, or (5) 2 secondary inpatient discharge diagnoses plus 1 outpatient diagnosis.Main Outcomes and MeasuresThe primary outcome was anthracycline-based treatment. The secondary outcomes were (1) cardioprotective medications and (2) cause-specific mortality. The associations between preexisting HF and cancer treatment were estimated using multivariable logistic regression. The associations between preexisting HF and cause-specific mortality were evaluated using cause-specific Cox proportional hazards models with adjustment for comorbidities and cancer treatment.ResultsOf 30 728 included patients with DLBCL, 15 474 (50.4%) were female, and the mean (SD) age was 77.8 (7.2) years. Preexisting HF at lymphoma diagnosis was present in 4266 patients (13.9%). Patients with preexisting HF were less likely to be treated with an anthracycline (odds ratio, 0.55; 95% CI, 0.49-0.61). Among patients with preexisting HF who received an anthracycline, dexrazoxane or liposomal doxorubicin were used in 78 of 1119 patients (7.0%). One-year lymphoma mortality was 41.8% (95% CI, 40.5-43.2) with preexisting HF and 29.6% (95% CI, 29.0%-30.1%) without preexisting HF. Preexisting HF was associated with higher lymphoma mortality in models adjusting for baseline and time-varying treatment factors (hazard ratio, 1.24; 95% CI, 1.18-1.31).Conclusions and RelevanceIn this study, preexisting HF in patients with newly diagnosed DLBCL was common and was associated with lower use of anthracyclines and lower use of any chemotherapy. Trials are needed for this high-risk population.

Abstract The International Federation of Clinical Chemistry Committee on Clinical Applications of Cardiac Biomarkers (IFCC C-CB) provides educational documents to facilitate the interpretation and use of cardiac biomarkers in clinical laboratories and practice. Our aim is to improve the understanding of certain key analytical and clinical aspects of cardiac biomarkers and how these may interplay. Measurements of cardiac troponin (cTn) have a prominent place in the clinical work-up of patients with suspected acute coronary syndrome. It is therefore important that clinical laboratories know how to recognize and assess analytical issues. Two emerging analytical issues resulting in falsely high cTn concentrations, often several fold higher than the upper reference limit (URL), are antibody-mediated assay interference due to long-lived cTn-antibody complexes, called macrotroponin, and crosslinking antibodies that are frequently referred to as heterophilic antibodies. We provide an overview of antibody-mediated cTn assay interference and provide recommendations on how to confirm the interference and interpret the results.

Cardiovascular biomarkers play a major diagnostic role for cardiologists. Different biomarkers provide different insights into a variety of cardiovascular conditions and in doing so they improve diagnosis and management. Often, these biomarkers are deployed without carefully evaluating the use of sex-specific cut off values. It is now becoming apparent that the use of such cut off values can improve prognostication and discrimination in some clinical situations. This review paper will focus on the data indicating that there is benefit to the use of sex-specific thresholds. It should be clear that these thresholds will vary depending on the analyte being measured and the specific clinical indication for which the patients are being evaluated; and sex-specific cut off values may be important in some situations but not others. Nonetheless, it is now clear that when evaluating sex-specific cut off values, one often finds benefit. We will highlight these situations using specific cardiac biomarkers as examples.

Abstract Background Myocardial injury after non-cardiac surgery (MINS), based on measurement of troponin T, is associated with perioperative major adverse cardiovascular events (MACE). We therefore determined the high-sensitivity troponin I (hsTnI) thresholds associated with 30 day MACE after non-cardiac surgery. Methods We performed a nested biobank cohort study of 4553 patients from the Vascular Events in Non-Cardiac Surgery Patients Cohort Evaluation (VISION) Study. We measured hsTnI (ADVIA Centaur® hsTnI assay) on postoperative days 1 to 3 in patients ≥45 years undergoing non-cardiac surgery. An iterative Cox proportional hazard model determined peak postoperative hsTnI thresholds independently associated with MACE (i.e., death, myocardial infarction occurring on postoperative day 4 or after, non-fatal cardiac arrest, or congestive heart failure) within 30 days after surgery. Results MACE occurred in 89/4545 (2.0%) patients. Peak hsTnI values of <75 ng/L, 75 ng/L to <1000 ng/L, and ≥1000 ng/L were associated with 1.2% (95% CI, 0.9–1.6), 7.1% (95% CI, 4.8–10.5), and 25.9% (95% CI, 16.3–38.4) MACE, respectively. Compared to peak hsTnI <75 ng/L, values 75 ng/L to <1000 ng/L and ≥1000 ng/L were associated with adjusted hazard ratios (aHR) of 4.53 (95% CI, 2.75–7.48) and 16.17 (95% CI, 8.70–30.07), respectively. MACE was observed in 9% of patients with peak hsTnI ≥75 ng/L vs 1% in patients with peak hsTnI <75 ng/L (aHR 5.76; 95% CI, 3.64–9.11). A peak hsTnI ≥75 ng/L was associated with MACE in the presence (aHR 9.35; 95% CI, 5.28–16.55) or absence (aHR 3.99; 95% CI, 2.19–7.25) of ischemic features of myocardial injury. Conclusion A peak postoperative hsTnI ≥75 ng/L was associated with >5-fold increase in the risk of 30 days MACE compared to levels <75 ng/L. This threshold could be used for MINS diagnosis when the ADVIA Centaur hsTnI assay is used. Clinicaltrials.gov Registration Number: NCT00512109.

Abstract The International Federation of Clinical Chemistry and Laboarator Medicine (IFCC) Committee on Clinical Applications of Cardiac Bio-Markers (C-CB) has provided evidence-based educational resources to aid and improve the understanding of important analytical and clinical aspects of cardiac biomarkers. The present IFCC C-CB educational report focuses on recommendations for appropriate use, analytical performance, and gaps in clinical studies related to the use of cardiac troponin (cTn) by point of care (POC) measurement, often referred to as a point of care testing (POCT). The use of high-sensitivity (hs)-cTn POC devices in accelerated diagnostic protocols used in emergency departments or outpatient clinics investigating acute coronary syndrome has the potential for improved efficacy, reduction of length of stay and reduced costs in the health care system. POCT workflow integration includes location of the instrument, assignment of collection and testing responsibility to (non-lab) staff, instrument maintenance, in-service and recurrent training, quality control, proficiency assessments, discrepant result trapping, and troubleshooting and inventory management.