Do medicines that lengthen the heart's QT interval cause serious heart problems in hospitalized adults?

Do 'Known' QT-prolonging Medications Cause Major Adverse Cardiac Events in Hospitalized Adults? The QTP-MACE Study

Observational St. Joseph's Healthcare Hamilton · NCT07374263

This project will test whether commonly used hospital medicines that can prolong the heart's QT interval lead to serious cardiac events in adults admitted to Ontario hospitals.

Quick facts

Study typeObservational
Enrollment990000 (estimated)
Ages18 Years and up
SexAll
SponsorSt. Joseph's Healthcare Hamilton Academic / other
Locations2 sites (Hamilton, Ontario and 1 other locations)
Trial IDNCT07374263 on ClinicalTrials.gov

What this trial studies

Researchers will use anonymized electronic medical record data from the Ontario GEMINI network and Epic‑Dovetale, covering more than 990,000 eligible adult hospital admissions, to compare patients who experienced a major adverse cardiac event (MACE) with those who did not. The team will perform a nested case‑control analysis and time-varying exposure analyses to measure whether exposure to listed 'known' QT‑prolonging medications during hospitalization is associated with a composite MACE outcome of death, non-fatal cardiac arrest, ventricular arrhythmia, or syncope. In addition, machine‑learning algorithms will be trained to predict QTPmed-associated MACE and to determine the relative importance of predictors. Results will be used to improve the accuracy and clinical usefulness of medication safety alerts.

Who should consider this trial

Good fit: Ideal candidates are adults (18 years or older) admitted to St. Joseph's Healthcare Hamilton or GEMINI-affiliated hospitals between December 2017 and March 2025 whose anonymized inpatient records are included in the EMR datasets.

Not a fit: Children under 18, outpatient encounters, and patients treated outside the participating hospitals or outside the specified date range are not included and therefore will not directly benefit from this project.

Why it matters

Potential benefit: If successful, the findings could make QT‑prolonging medication alerts more accurate, reduce unnecessary clinician interruptions and burnout, and help prevent some serious cardiac events.

How similar studies have performed: Existing evidence linking many listed 'known' QT‑prolonging drugs to major cardiac events is sparse and low-quality, so this large EMR and machine‑learning approach is relatively novel and aims to provide stronger evidence.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Adult patients 18 years of age or older
* Admitted to St. Joseph's Healthcare Hamilton or GEMINI hospitals between December 2017 and March 2025

Exclusion Criteria:

* Patients \<18 years old
* Outpatient encounters

Where this trial is running

Hamilton, Ontario and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Acquired Long QTVentricular ArrhythmiasTorsades de PointesSyncopeMedication SafetyMACEMedication safetyQT interval prolongation
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.