Analysis of Life-threatening ARrhythMias After Acute Coronary Syndrome (ALARM-ACS)

September 11, 2026 updated by: Luuk Otterspoor, Catharina Ziekenhuis Eindhoven

Current Relevance of Malignant Cardiac Arrhythmia in Patients Admitted for Acute Coronary Syndrome

Patients admitted with an acute coronary syndrome (ACS) are at increased risk of malignant cardiac arrhythmias (MA), such as sustained ventricular tachycardia and ventricular fibrillation. Therefore, patients with ST-elevation myocardial infarction (STEMI) are continuously monitored for a minimum of 24 hours after onset symptoms. Longer monitoring is advised in patients at intermediate to high risk of cardiac arrhythmias, however this risk stratification is not evidence based. Hospitalization, particularly in STEMI patients, is advised for a minimum of 48-72 hours.

AMI care requires a substantial commitment of bed capacity and staff, resulting in high healthcare costs.

In patients who have undergone acute PCI (such as STEMI patients or NSTEMI patients with persistent symptoms), monitoring is primarily aimed at early recognition of MA and signs of persistent or recurrent ischaemia after the intervention.

In NSTEMI/UAP patients still awaiting invasive treatment, the emphasis lies on detecting increasing ischaemia in the as-yet untreated coronary vessel, as well as identifying arrhythmias that may arise as a result.

The true incidence of MA cannot be precisely established due to heterogeneity in the literature, and moreover varies between patients with ST-elevation myocardial infarction, non-ST-elevation myocardial infarction, and unstable angina pectoris, owing to differences in disease process and care pathway.

A better understanding of the current incidence and risk of MA in patients with ACS may contribute to optimizing the monitoring of this patient group, thereby enabling more efficient use of hospital beds and healthcare staff. This prospective quality registry therefore aims to establish the current incidence of MA in ACS patients and to identify potential predictors of MA, while also taking into account other acute complications such as asystole and pulseless electrical activity (PEA).

Study Overview

Detailed Description

Primary research question:

What is the incidence of malignant arrhythmias (MA, defined as sustained ventricular tachycardia/ventricular fibrillation) during admission in patients with acute coronary syndrome?

Secondary research questions:

What is the incidence of MA during admission in the subgroups:

ST-elevation myocardial infarction (STEMI) Non-ST-elevation myocardial infarction (NSTEMI) Unstable angina pectoris (UAP) What is the temporal relationship of MA occurrence during admission, and can a peak incidence be identified? What are clinical predictors of MA during admission in patients with acute coronary syndrome? How do polymorphic and monomorphic ventricular arrhythmias compare in terms of frequency of occurrence in patients admitted with acute coronary syndrome? What is in-hospital mortality in ACS patients with versus without MA? What is the incidence of asystole and pulseless electrical activity (PEA) during admission in patients with acute coronary syndrome?

Study Type

Observational

Enrollment (Estimated)

2775

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Patients aged 18 years or older with acute coronary syndrome (ACS) (ST-elevation myocardial infarction, non-ST-elevation myocardial infarction, and unstable angina pectoris) or out-of-hospital cardiac arrest (OHCA) due to ACS, admitted to the emergency cardiac care unit, emergency department, coronary care unit (CCU), intensive care unit (ICU), or cardiology ward.

Description

Inclusion criteria Patients aged 18 years or older with acute coronary syndrome (ST-elevation myocardial infarction, non-ST-elevation myocardial infarction, and unstable angina pectoris) or out-of-hospital cardiac arrest (OHCA) due to ACS, admitted to the emergency cardiac care unit, emergency department, coronary care unit (CCU), intensive care unit (ICU), or cardiology ward.

Exclusion criteria Patients who have indicated that their data may not be used for scientific research or for improving the quality of care.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Patients aged 18 years or older admitted with acute coronary syndrome
Patients aged 18 years or older with acute coronary syndrome (ACS) (ST-elevation myocardial infarction, non-ST-elevation myocardial infarction or unstable angina pectoris) or out-of-hospital cardiac arrest (OHCA) due to ACS, admitted to the emergency cardiac care unit, emergency department, coronary care unit (CCU), intensive care unit (ICU), or cardiology ward.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Occurrence of one (or more) malignant arrhythmia(s) (sustained VT or VF) during admission
Time Frame: During admission

Occurrence of one (or more) malignant arrhythmia(s) (sustained VT or VF) during admission, defined as from the moment of physical hospital admission until discharge.

(For OHCA patients, the index arrhythmic event preceding hospital admission is not counted as a malignant arrhythmia event; only events occurring from the moment of physical hospital admission onward are included.)

(Events of sustained VT or VF occurring during admission of an ACS patient following cardiac surgery, such as CABG, will not be included.)

During admission

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Asystole/PEA
Time Frame: During admission

Secondary outcome: Occurrence of one (or more) asystole and/or pulseless electrical activity (PEA) event(s) during admission, defined as from the moment of physical hospital admission until discharge.

(For OHCA patients, the index arrhythmic event preceding hospital admission is not counted as an asystole/PEA event; only events occurring from the moment of physical hospital admission onward are included.)

(Events of asystole or PEA occurring during admission of an ACS patient following cardiac surgery, such as CABG, will not be included.)

During admission

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Luuk C Otterspoor, Dr. M.D., Catharina Ziekenhuis Eindhoven

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

July 14, 2026

Primary Completion (Estimated)

April 1, 2029

Study Completion (Estimated)

April 1, 2029

Study Registration Dates

First Submitted

September 11, 2026

First Submitted That Met QC Criteria

September 11, 2026

First Posted (Actual)

September 17, 2026

Study Record Updates

Last Update Posted (Actual)

September 17, 2026

Last Update Submitted That Met QC Criteria

September 11, 2026

Last Verified

September 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Sensitive patient data, no permission to be shared externally

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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