Prevalence and prognostic impact of myocardial injury following hypertensive crisis

Background In patients with acute chest pain, hypertensive crisis is a common possible diagnosis. Severe hypertension may even cause elevated levels of cardiac troponin indicating myocardial injury. Whether this biomarker response is linked to poorer outcome is unknown. Methods We included patients presenting to the emergency department with suspected myocardial infarction. In accordance with the 4th definition of myocardial infarction the final diagnosis and main cause of symptoms was adjudicated by two trained cardiologists based on all available clinical, imaging and laboratory data, including high-sensitive troponin T (hs-TnT). Hypertensive crisis was confirmed by the adjudicators if an elevation of systolic blood pressure (>160 mmHg) was detected and after careful review of all available data other differential diagnoses were less likely. Patients were stratified in those with myocardial injury (acute or chronic) based on sex-specific hs-TnT cutoffs or those without. Kaplan-Meier survival analysis were calculated for all-cause mortality and a composite of death, myocardial infarction, revascularization or cardiac rehospitalization. The event-rates during two-year follow-up were compared using the log-rank test. Cox-proportional hazard ratios were calculated for each patient group with adjustment for age and sex for 2-year all-cause mortality. Results Out of 2,565 patients 446 (17.4%) had a final diagnosis of hypertensive crisis. Of these, 213 (47.8%) developed myocardial injury with a baseline hs-TnT of 15.0 (IQR 10.0-22.0) ng/L. Among the remaining 2,119 patients with other diagnoses than hypertensive crisis, 910 (42.9%) showed myocardial injury with a baseline hs-TnT of 28.5 (IQR 17.0-67.2) ng/L. Patients with hypertensive crisis accompanied by myocardial injury were older (76 (IQR 68-82) vs 60 (IQR 52-71) years, p=0.001) and more often female (61.0% vs 39.5%, p=0.001). Among patients with hypertensive crisis, 2-year mortality rates were higher in patients with myocardial injury compared to non-injury. However, compared to patients with myocardial injury due to other causes, hypertensive patients showed significantly better outcome (p=0.027; Figure 1A). This was consistent for the combined clinical endpoint (Figure 1B). Compared to non-injury/non-hypertensive patients, hazard ratio (HR) for all-cause death after 2 years was not significant for non-injury/hypertensive patients (HR 0.52 (95% CI 0.19-1.48), p=0.22), while patients with myocardial injury and hypertensive crises had significantly increased risk of death after 2 years (HR 1.81 (95% CI 1.02-3.22), p=0.044). In patients with myocardial injury caused by other reasons risk of death was even higher (HR 3.58 (95% CI 2.38-5.39), p=0.001). Conclusion Patients with myocardial injury due to hypertensive crisis are at high risk for adverse outcome within 2 years after presentation. However, compared to other reasons for myocardial injury hypertensive crisis seems less hazardous.