May 13, 2016 | Yader Sandoval, MD
Education

Dr. Sandoval is a co-investigator within Fred Apple, PhD’s Cardiac Biomarkers Trials Laboratory at the Minneapolis Medical Research Foundation, where he collaborates with both Dr. Apple, (Laboratory Medicine and Pathology) and Stephen W. Smith, MD (Emergency Medicine). Dr. Sandoval’s research has focused on the use of cardiac troponin in acute myocardial infarction (MI), including the diagnosis, classification, management and risk-stratification of myocardial injury and MI. Dr. Sandoval presented the following results at ACC’s 65th Annual Scientific Sessions (ACC.16) at the Young Investigator Awards Competition session and was honored as one of the five finalists during the Convocation Ceremony:

Cardiac troponin (cTn) is central to the diagnosis of acute MI¹. In the U.S., contemporary sensitive cTn assays are widely used to assist with the rule-in and rule-out of acute MI². High-sensitivity (hs)-cTn assays, not yet cleared for clinical use by the U.S. Food and Drug Administration (FDA), provide superior analytical sensitivity and improved precision at very low concentrations². Several strategies geared toward expediting the safe rule-out of acute MI have been studied in recent years using hs-cTn assays²; including the use of undetectable values, accelerated serial sampling, hs-cTn in combination with risk scores, and the use of a single hs-cTn measurement with a concentration tailored to meet a clinical need³. Most of these studies were performed outside the U.S. in select cohorts of patients with chest pain and focused on the endpoint of acute MI.

In a prospective, observational cohort study of 1,647 consecutive unselected patients presenting to the emergency department undergoing serial cTnI measurements on clinical indication, Sandoval and colleagues sought to determine whether a single cTnI measurement at presentation with concentrations under the limit of detection (LoD) of a hs-cTnI assay could rule-out acute myocardial injury, regardless of the mechanism of injury, alone or in combination with a non-ischemic electrocardiogram, and examined the safety of the proposed rule-out strategy by assessing for acute MI and cardiac death at 30 days. Using this approach, 27 percent of patients qualified for the proposed immediate rule-out strategy with an excellent negative predictive value and diagnostic sensitivity for acute myocardial injury of 99.1 percent and 99.0 percent, respectively. At 30 days, the negative predictive value for acute MI and cardiac death was 99.6 percent.

These results are timely and important, as they address an unselected, heterogeneous patient cohort typical of clinical practice in the U.S. emergency department. Moreover, by ruling out acute myocardial injury (defined by cTn increases above the 99^th percentile), which encompasses acute MI, a reproducible endpoint that avoids the present controversies related to the adjudication and classification of acute MI is offered⁴.

1. Thygesen K, Alpert JS, Jaffe AS et al. Third universal definition of myocardial infarction. J Am Coll Cardiol 2012; 60: 1581-98.
2. Sandoval Y, Smith SW, Apple FS. Present and Future of Cardiac Troponin in Clinical Practice: A Paradigm Shift to High Sensitivity Assays. Am J Med 2016; 129: 354-65.
3. Shah AS, Anand A, Sandoval Y et al. High-sensitivity cardiac troponin I at presentation in patients with suspected acute coronary syndrome: a cohort study. Lancet 2015; 386: 2481-8.
4. Sandoval Y, Smith SW, Thordsen SE, Apple FS. Supply/demand type 2 myocardial infarction: should we be paying more attention? J Am Coll Cardiol 2014; 63: 2079-87.

The research in this article was originally published in the Journal of the American College of Cardiology. View the full research here.

This article was authored by Yader Sandoval, MD a Chief Cardiovascular Disease Fellow at Hennepin County Medical Center and the Minneapolis Heart Institute, Abbott Northwestern Hospital in Minneapolis, MN