Diagnoses and Outcomes of Patients with Suspicion of Acute Coronary Syndrome and Raised High Sensitive Troponin I: A Single Center Study from Pakistan

Objectives  Troponins are classically raised in acute coronary syndrome (ACS) although other cardiovascular and non-cardiovascular causes are recognized. We aimed to see the association of high sensitivity (Hs) Troponin I values exceeding the sex-specific 99th percentile upper reference limit (URL) with diagnoses, emergency department (ED) outcomes, 30-day outcomes of admitted patients and predictors of ACS in both genders. Materials and Methods  A retrospective study of all patients presenting to the emergency department from January 2019 to April 2021 with suspicion of ACS and Hs-Troponin I values greater than the sex-specific 99th percentile URL. Statistical Analysis  SPSS version 24 was used, Pearson's chi-square tests, Fisher's exact test, Kruskal-Wallis test, Mann-Whitney U test, and odds ratios, including the 95% confidence intervals, for each characteristic were used for analysis. A p -value of < 0.05 was considered significant. Results  There were a total of 5,982 patients (3,031 males, 2,951 females), out of which 878 patients were admitted under the cardiology specialty. In patients who were admitted to the ward, mortality was higher in females (8.2%) with less than a 10-fold rise in Hs-Troponin I while similar in both genders (7.6%) in patients with Hs-troponin I greater than 10-fold of sex-specific 99th percentile URL. Raised low-density lipoprotein-cholesterol was a significant factor associated with 2.4 times higher odds of ACS. Conclusion  Women with Hs-Troponin values up to 10 times the URL, i.e., 15.6-160 ng/L have higher mortality than their male counterparts. LDL-cholesterol is a significant risk factor for ACS which should be controlled for its prevention.

Single Troponin Measurement to Rule Out Myocardial Infarction: JACC Review Topic of the Week

The term "single-sample rule-out" refers to the ability of very low concentrations of high-sensitivity cardiac troponin (hs-cTn) on presentation to exclude acute myocardial infarction with high clinical sensitivity and negative predictive value. Observational and randomized studies have confirmed this ability. Some guidelines endorse use of a concentration of hs-cTn at the assay's limit of detection, while other studies have validated the use of higher concentrations, allowing this approach to identify a greater proportion of patients at low risk. In most studies, at least 30% of patients can be triaged with this approach. The concentration of hs-cTn varies according to the assay used and sometimes how regulations permit reporting. It is clear that patients need to be at least 2 hours from the onset of symptoms being evaluated. Caution is warranted, particularly with older patients, women, and patients with underlying cardiac comorbidities.

Risk Scores for Clinical Risk Stratification of Emergency Department Patients With Chest Pain but No Acute Myocardial Infarction: A Systematic Review

BACKGROUND

Chest pain is a common cause for emergency department (ED) presentations. After myocardial infarction (MI) has been ruled out by means of electrocardiography and troponin testing, decisions around anatomic or functional testing may be informed by clinical risk scores. We conducted a systematic review to synthesize evidence of the prognostic performance of chest pain risk scores among ED patients who have had MI ruled out by means of a high-sensitivity troponin assay.

METHODS

We queried multiple databases from inception to May 17, 2022. We included studies that quantified risk of 30-day major adverse cardiac events (MACE), at different cutoffs of clinical risk scores, among adult patients who had MI ruled out by means of a high-sensitivity troponin assay. Prognostic performance of each score was synthesized and described, but meta-analysis was not possible.

RESULTS

Six studies met inclusion criteria. Short-term MACE risk among patients who had MI ruled out by means of high-sensitivity cardiac troponin assays was very low. The HEART score, with a cutoff of 3 or less, predicted a very low risk of MACE among the greatest proportion of patients. Other scores had lower sensitivity or classified fewer patients as low risk.

CONCLUSIONS

The HEART score with a cutoff value of 3 or less accurately identified the greatest number of patients at low risk of 30-day MACE. However, MACE risk among patients who have MI ruled out by means of high-sensitivity troponin testing is sufficiently low that clinical risk stratification or noninvasive testing may be of little additional value in identifying patients with coronary disease.

Development and validation of a risk score for chest pain with suspected non-ST-segment elevation acute coronary syndrome

Objective

To investigate a new risk score for acute chest pain with suspected non‐ST‐segment elevation acute coronary syndrome (NSTE‐ACS).

Methods

Patients who suffered from Chest pain and suspected NSTE‐ACS were enrolled as subjects. Predictor variables had been analyzed, and a bootstrap technique was used to evaluate the internal validity of the model, and external validation had been assessed for a prospective cohort study.

Results

Thousand five hundred and sixty‐eight patients had been included in this study. Six predictor variables were found to be significant and were used to develop the model. The C‐statistic of the model was 0.83, and internal validation revealed the stability of the model and the absence of over‐optimism. Patients were given different triage recommendations, and the risk score was prospectively validated.

Conclusions

A risk score may be a suitable method for assessing the risk of major adverse cardiac events and aiding patient triage in emergency departments among patients with suspected NSTE‐ACS.

Early Rule-Out Strategies in the Emergency Department Utilizing High-Sensitivity Cardiac Troponin Assays

BACKGROUND

Over the past decade, intense collaboration between academic investigators and the diagnostic industry have allowed the integration of high-sensitivity cardiac troponin (hs-cTn) assays into clinical practice worldwide. The hs-cTn assays, with their increased diagnostic accuracy for acute myocardial infarction (AMI), have facilitated the maturation of early rule-out strategies. The first iteration was complex and required the combination of a biomarker panel, the electrocardiogram, and a clinical risk score and allowed the safe rule-out of AMI in only 10% of patients with acute chest pain. In contrast, the latest iterations, including the European Society of Cardiology (ESC) 0/1-h algorithm, are simple. They are based on hs-cTn concentrations only and allow the safe rule-out or rule-in of AMI in up to 75% of patients.

CONTENT

The purposes of this minireview are (a) to describe the best validated hs-cTn-based strategies for early rule-out of AMI, (b) to discuss the advantages and limitations of the different strategies, (c) to identify patient subgroups requiring particular attention, (d) to recognize challenges for widespread clinical implementation, and (e) to provide guidance on strategies for their safe and effective clinical implementation.

SUMMARY

Physicians and institutions may choose among several well-validated rule-out algorithms. The ESC 0/1-h algorithm for hs-cTnT or hs-cTnI seems to be the most attractive option today. It best balances safety and efficacy, and it has been derived and validated for all currently available hs-cTnT/I assays, facilitating widespread clinical implementation.