Clinical implications of cardiac troponin-I in patients with hypertensive crisis visiting the emergency department

OBJECTIVES: Cardiac troponin-I (cTnI) is a representative marker of myocardial injury. Elevation of cTnI is frequently observed in patients with hypertensive crisis, but few studies have examined its prognostic significance in hypertensive crisis. We aimed to determine whether cTnI could predict all-cause mortality in patients with hypertensive crisis visiting the emergency department (ED). METHODS: This observational study included patients aged ≥18 years who visited an ED between 2016 and 2019 for hypertensive crisis, defined as systolic blood pressure (BP) ≥180 mmHg and/or diastolic BP ≥110 mmHg. Among 6467 patients, 3938 who underwent a cTnI assay were analysed. RESULTS: Among the 3938 patients, 596 (15.1%) had cTnI levels above the 99th percentile upper reference limit (elevated cTnI >40 ng/L) and 600 (15.2%) had cTnI levels between the detection limit (≥10 ng/L) and the 99th percentile upper reference limit (detectable cTnI). The 3-year all-cause mortality in the elevated, detectable and undetectable cTnI groups were 41.6%, 36.5% and 12.8%, respectively. After adjusting for confounding variables, elevated cTnI patients (adjusted hazard ratio [HR], 2.01; 95% confidence interval [CI], 1.61–2.52) and detectable cTnI patients (adjusted HR, 1.64; 95% CI, 1.32–2.04) showed a significantly higher risk of 3-year all-cause mortality than did patients with undetectable cTnI. CONCLUSIONS: In patients with hypertensive crisis, elevated cTnI levels provide useful prognostic information and permit the early identification of patients with an increased risk of death. Moreover, putatively normal but detectable cTnI levels also significantly correlated with a higher risk of all-cause mortality. Intensive treatment and follow-up strategies are needed for patients with hypertensive crisis with elevated and detectable cTnI levels. KEY MESSAGES: 1. Cardiac troponin-I level was an independent prognostic factor for all-cause mortality in patients with hypertensive crisis. 2. Detectable but normal range cardiac troponin-I, which was considered clinically insignificant, also had a prognostic impact on all-cause mortality comparable to elevated cardiac troponin-I levels.