Prognostic Implications of High-Sensitivity Troponin T Levels Among Patients Attending Emergency Departments and Evaluated for an Acute Coronary Syndrome

BACKGROUND

With increasing age, patients with suspected acute coronary syndromes (ACS) and elevated high-sensitivity troponin T (HsTnT) levels, type-1 myocardial infarction (MI) is diagnosed less often, though associations among these factors, gender, and prognosis is unclear.

METHODS

Patients presenting to the emergency department (ED) with potential ACS who underwent HsTnT testing were prospectively identified and followed. Diagnoses were adjudicated according to the Fourth Universal Definition of MI as follows: type-1 MI, type-2 MI, acute myocardial injury, chronic myocardial injury, and other diagnoses. Age in years was categorized: younger (<65); elderly (65-79), and very elderly (≥80).

RESULTS

Among 2738 patients with HsTnT measurements, 1611 were suitable for adjudication (42% ages 65 years and younger). Type-2 MI and chronic myocardial injury diagnoses were more common in those ages 65 years and older, whereas younger patients had more type-1 MI diagnoses. Late mortality rates at median 41 months (interquartile range [IQR] 10-57) were 44% (223 out of 506) in those ages 80 years and older, 22% (92 out of 423) in patients 65-79 years, and 7% (46 out of 682) in those 65 years and younger, irrespective of adjudicated diagnoses, log rank P ≤ .001. On multivariable analyses, the adjusted mortality hazard ratios for increasing HsTnT levels irrespective of diagnoses were attenuated in those age 80 years and older compared to younger patients.

CONCLUSIONS

Patients ages 65 years and older constituted ~60% of ED attendances of patients with suspected ACS, and more had type 2 MI and chronic myocardial injury diagnoses compared to younger patients. The relative mortality impact of HsTnT levels was lower among elderly patients irrespective of adjudicated diagnoses.

Type-II myocardial infarction and chronic myocardial injury rates, invasive management, and 4-year mortality among consecutive patients undergoing high-sensitivity troponin T testing in the emergency department

AIMS

As assessment of patients with suspected acute coronary syndromes (ACS) in emergency departments (EDs) represents a major workload because high-sensitivity troponin (HsTn) T and I levels are frequently measured, and a minority of patients have final diagnosis of myocardial infarction (MI). We determined the relative frequencies of three patients groups: Type-I MI, Type-II MI (including acute myocardial injury).

METHODS AND RESULTS

Among 2738 consecutive patients with suspected ACS presenting to ED at Liverpool Hospital, Australia, between March and June 2014. We studied the use of invasive and pharmacological therapies, and 4-year outcomes. Adjudication of MI was according to the 4th universal definition as follows: (i) Type-I MI; (ii) Type-II MI (including acute myocardial injury), and (iii) chronic myocardial injury. Of 995 patients (36%) [median age 76 years (interquartile range 65-83)] with ≥2 HsTnT measurements and one >14 ng/L, 727 (73%) had chronic myocardial injury, 171 (17%) had Type-II MI, and 97 (9.7%) had Type-I MI; respective late mortality rates to 48 months were 33%, 43%, and 14% (P < 0.001). In-hospital angiography rates were 95% for patients with Type-I MI, [62% had percutaneous coronary intervention (PCI)] 24% (7% PCI) for those with Type-II MI, and 3.4% for chronic myocardial injury. On Cox modelling for mortality relative to Type 1 MI, adjusted hazard ratios were 1.94 [95% confidence intervals (CIs) 1.06-3.57]; P = 0.032 for Type 2 MI, and for chronic myocardial injury 1.14 (95% CIs 0.64-2.02); P = 0.66.

CONCLUSION

Among unselected patients undergoing HsTnT testing in EDs, Type-II MI including acute myocardial injury was more common than Type-I MI. Chronic myocardial injury, which occurred in three of four patients. Whereas patients with Type-II MI had higher late mortality than those with Type-I MI, after multivariable analyses mortality rates were marginally different.

Mortality at 5 Years Among Very Elderly Patients Undergoing High Sensitivity Troponin T Testing for Suspected Acute Coronary Syndromes

BACKGROUND

Patients aged ≥80 years old often present to Emergency Departments (ED) with symptoms potentially due to an acute coronary syndrome (ACS). This study aimed to evaluate associations between baseline level(s) of high sensitivity troponin T (HsTnT), adjudicated diagnoses and outcomes.

METHODS

Consecutive patients aged ≥80 years were studied, who presented to the ED at Liverpool Hospital, NSW, Australia during the 4 months period March to June 2014 (inclusive) with symptoms suggestive of an ACS, and who had at least one HsTnT assay performed. Diagnoses were based on the fourth universal definition of MI (myocardial infarction) including type-1 MI, type-2 MI, acute myocardial injury, chronic myocardial injury; the rest were termed "other diagnoses". Patients were categorised by baseline HsTnT levels 1) ≤14 ng/L, 2) 15-29 ng/L, 3) 30-49 ng/L and 4) ≥50 ng/L.

RESULTS

Of 2,773 patients screened, 545 were aged ≥80 years (median age 85 [IQR 82-88]); median follow-up was 32 months (IQR 5-56). The respective rates of adjudicated diagnoses were type-I MI 3.1%, type-2 MI 13%, acute myocardial injury 9.5%, chronic myocardial injury 56% and 18.6% had other diagnoses. Mortality rates increased, irrespective of adjudicated diagnoses with increasing HsTnT levels (ng/L): 17% (16/96) for ≤14; 35% (67/194) for 15-29; 51% (65/127) for 30-49; and 64% (82/128) for ≥50 ng/L; log rank p≤0.001. On multi-variable analyses, after adjusting for potential confounding factors including age, hypertension, chronic kidney disease (CKD) and chronic obstructive pulmonary disease (COPD), MI type was not associated with late mortality.

CONCLUSIONS

Among patients aged ≥80 years higher HsTnT levels, irrespective of adjudicated diagnoses, were associated with increased mortality. Most very elderly patients presenting with symptoms suggestive of an ACS undergoing HsTnT testing in EDs had elevated levels most commonly due to chronic myocardial injury. Whether any interventions can modify outcomes require prospective evaluation.

P2717Type-II MI and chronic myocardial injury rates, invasive management and 4 year mortality among consecutive patients undergoing high sensitivity troponin T testing in the emergency department

Background

In emergency departments (EDs), assessment of patients with suspected acute coronary syndromes (ACS) represents a major workload and high sensitivity troponin (HsTn) T and I levels are frequently measured. A minority of patients have final diagnosis of myocardial infarction (MI).

Methods and results

Among 2738 consecutive patients with suspected ACS presenting to ED at Liverpool Hospital, Australia, between March and June 2014, we determined the relative frequencies of 3 patient groups: type-I MI, type-II MI including chronic myocardial injury (CMI), and assessed the use of invasive and pharmacological therapies and 4-year outcomes. Adjudication of MI was according to the 4th universal definition of MI as follows: 1) type-I MI; 2) type-II MI (including acute myocardial injury), and 3) CMI. Of 995 patients (36%) median age 76 years [IQR 65–83]), with at least 2 HsTnT measurements and one >14ng/l, 727 (73%) had chronic myocardial injury, 171 (17%) had type-II MI; and 97 (9.7%) had type-I MI. Patients with type-I MI (mean age 63 years) were younger than those with type-II MI or chronic myocardial injury by 12 and 14 years respectively. The main triggering factors for type-II MI/acute injury included: sepsis (21.1%), acute heart failure (18.3%), tachyarrhythmia (16.9%), anaemia (8.6%) and a combination of factors (16%). In-hospital angiography (62% had PCI) rates were 95% for patients with type-I MI, 24% (7% PCI) for those with type-II MI and 3.4% for CMI. Mortality at 4 years was 55% for type-II MI, 44% for CMI and 18% for type-1 MI (P<0.001; Figure), though after Cox modelling adjusting for age, gender, renal function and COPD, compared to type 1 MI, type-II MI (hazard ratio 1.61 [95% CIs 0.90–2.86]; p=0.106) and CMI (hazard ratio 1.01 [95% CIs 0.59–1.74]; p=0.963) were not independently associated with increased late mortality, largely because patients with type 1 MI were a decade younger.

Conclusion

Among unselected patients undergoing HsTnT testing in EDs, type-II MI including acute myocardial injury was more common than type-I MI. Chronic myocardial injury, which occurred in 3 of 4 patients. While patients with type-II MI acute myocardial injury had higher late mortality rates than type-I MI, though after multivariable analyses mortality rates were not different.