One-Hour Algorithm Safe for Rule-Out/Rule-In of Acute MI
(HealthDay News) – An algorithm using high-sensitivity cardiac troponin T (hs-CTnT) levels at baseline and after one hour can be used to successfully rule out or accurately diagnose acute myocardial infarction (AMI) in the majority of patients who present with acute chest pain.
Tobias Reichlin, MD, of the University Hospital Basel in Switzerland, and colleagues conducted a multicenter prospective study involving 872 patients who presented to the hospital emergency department with acute chest pain. For each patient, hs-CTnT was measured at baseline and after one hour. Using data from half the patients, an algorithm, incorporating baseline values and absolute changes within the first hour, was developed. The algorithm was then validated using the second half of the patient group.
The researchers found that, based on hs-CTnT measurements and the algorithm that was developed, physicians were able to rule out 60% of the patients in the validation cohort and rule in 17% of patients, with 23% remaining in an observation zone for one hour. For rule-out, the sensitivity and negative predictive value were 100%; for rule-in, the specificity was 97% and positive predictive value was 84%. The prevalence of AMI in the observational group was 8%. For patients classified as rule-out, observation-zone, or rule-in, the cumulative 30-day survival was 99.8, 98.6, and 95.3%, respectively.
"The use of this algorithm seems to be safe, significantly shortens the time needed for rule-out and rule-in of AMI, and may obviate the need for prolonged monitoring and serial blood sampling in three of four patients with chest pain," the authors write.
One author disclosed financial ties to pharmaceutical companies, including Abbot, Roche, and Siemens, all of which funded the study. Roche donated the hs-CTnT assay used in the study.