Feasibility of the Manchester Acute Coronary Syndromes (MACS) decision rule to safely reduce unnecessary hospital admissions: a pilot randomised controlled trial

Abstract

BackgroundObservational studies suggest that the Manchester Acute Coronary Syndromes (MACS) decision rule can effectively ‘rule out’ and ‘rule in’ acute coronary syndromes (ACS) following a single blood test. In a pilot randomised controlled trial, we aimed to determine whether a large trial is feasible.MethodsPatients presenting to two EDs with suspected cardiac chest pain were randomised to receive care guided by the MACS decision rule (intervention group) or standard care (controls). The primary efficacy outcome was a successful discharge from the ED, defined as a decision to discharge within 4 hours of arrival providing that the patient did not have a missed acute myocardial infarction (AMI) or develop a major adverse cardiac event (MACE: death, AMI or coronary revascularisation) within 30 days. Feasibility outcomes included recruitment and attrition rates.ResultsIn total, 138 patients were included between October 2013 and October 2014, of whom 131 (95%) were randomised (66 to intervention and 65 controls). Nine (7%) patients had prevalent AMI and six (5%) had incident MACE within 30 days. All 131 patients completed 30-day follow-up and were included in the final analysis with no missing data for the primary analyses. Compared with standard care, a significantly greater proportion of patients whose care was guided by the MACS rule were successfully discharged within 4 hours (26% vs 8%, adjusted OR 5.45, 95% CI 1.73 to 17.11, p=0.004). No patients in either group who were discharged within 4 hours had a diagnosis of AMI or incident MACE within 30 days (0.0%, 95% CI 0% to 20.0% in the intervention group).ConclusionsIn this pilot trial, use of the MACS rule led to a significant increase in safe discharges from the ED but a larger, fully powered trial remains necessary. Our findings seem to support the feasibility of that trial.Trial registration numberISRCTN 86818215.Research Ethics Committee reference13/NW/0081.UKCRN registration ID14334.

Multicentre cross-sectional observational registry to monitor the safety of early discharge after rule-out of acute myocardial infarction by copeptin and troponin: the Pro-Core registry

“…Integration of clinical judgement or a validated clinical score such as the GRACE, TIMI, HEART, modified Goldman Score, MACS clinical decision rule, EDACS and Vancouver Chest Pain Algorithm and North American Chest Pain Rule further improve NPV yielding NPV between 98.1% to 100% and 98.4% to 100% when cTn and hs-cTn assays were used, respectively 40. Although, 2015 ESC guidelines10 discourage routine invasive strategy in low risk patients and rather recommend discharge following risk stratification, and a pre-discharge or post-discharge stress imaging test to decide on a selective invasive strategy, evidence from randomised trials to endorse these recommendations is sparse 20–22. The Manchester Acute Coronary Syndrome (MACS)-Pilot study20 enrolled 138 patients with suspected cardiac chest pain who were randomised to receive care guided by the MACS decision rule or standard care.…”

“…In fact, most of the patients who retrospectively fulfilled early rule-out criteria were kept in hospital and neither medical measures nor non-cardiac diagnoses are reported. Only few interventional clinical trials evaluated the safety of a randomised allocation to early discharge versus conventional care in patients at low20 21 or low-to-intermediate high risk 22. The Biomarkers-in-Cardiology 8 (BIC-8) trial22 tested the utility of a dual biomarker strategy using normal cTn or hs-cTn values, that is below the upper limit of normal, mainly the 99 th percentile, together with normal Copeptin values below the 95 th percentile (<10 pmol/L) to identify candidates for direct early discharge from the ED.…”

“…The value of Copeptin on top of detectable but still normal cTn or hs-cTn for rule-out of MI has been studied extensively and the dual marker strategy (DMS) algorithm has been quoted as an additional option for instant rule-out in 2015 ESC guidelines 10. In contrast, there is sparse information from randomised trials on the safety of discharge20 21 and the safety of discharge using a prespecified algorithm has rarely been investigated in a prospective registry.…”

Heart-type fatty acid-binding protein: an overlooked cardiac biomarker

“…Test characteristics of H-FABP versus hs-Tn in those presenting to ED with CP, stratified by time to symptom onset. recent pilot RCT found that the MACS rule enabled 26% patients to be successfully discharged from the ED within 4 h with no incident AMI in 30 days among those discharged [63]. Similarly, an analysis of a singlecenter arm of the multi-center ADAPT study found that when combined with EKG, H-FABP orhs-Tn alone had unacceptably low sensitivity [64].…”

Acute coronary syndromes diagnosis, version 2.0: Tomorrow's approach to diagnosing acute coronary syndromes?

“…Use of the decision aid led to an increase in the proportion of patients safely discharged from the ED within 4 h of arrival (adjusted odds ratio 5.5, 95% CI 1.7–17.1, p = 0.004), although the analysis was underpowered to specifically study the incidence of MACE in the ‘very low risk’ group. 37 …”