The Purdue College of Pharmacy recognizes the groundbreaking research of Dr. James Tisdale, whose recent study sheds light on a significant risk factor for drug-induced QT interval prolongation, which can lead to the life-threatening arrhythmia known as torsades de pointes. His research, titled “Drug-induced QT interval prolongation in patients with heart failure with preserved ejection fraction,” was recently published in PLoS One and highlights critical findings for the medical and pharmaceutical fields.
A researcher from Purdue University’s College of Pharmacy, has identified a new risk factor for a specific type of drug-induced irregular heart rhythm.
James Tisdale, professor of pharmacy practice, and his research colleagues, set out to study QT interval prolongation, a condition in which the heart’s electrical system takes longer than it should to reset after a heartbeat. The condition, a known side effect of certain medications, is a dangerous electrocardiogram (ECG) abnormality that can lead to life-threatening arrhythmias.
“QT prolongation is a known side effect of medications like dofetilide and sotalol, which are frequently prescribed for atrial fibrillation, a heart rhythm disorder where the upper chambers of the heart beat irregularly and rapidly,” Tisdale said. “Prior to this study, it was well-established that patients with heart failure with reduced ejection fraction (HFrEF) were at increased risk for this condition; however, the risk level for patients with heart failure with preserved ejection fraction (HFpEF) remained unclear.”
Analyzing patient medical records, the research team found that among patients taking dofetilide or sotalol, QT prolongation was notably more prevalent among those with HFrEF (71.7%) and HFpEF (53.2%) compared to individuals without heart failure (30.0%). Furthermore, patients with HFpEF had nearly twice the likelihood of experiencing QT prolongation compared to those without heart failure.
The finding is significant because it identifies HFpEF as a new risk factor for drug-induced QT prolongation, Tisdale said.
“With nearly 200 medications available in the U.S. that can cause this dangerous ECG abnormality, pharmacists and healthcare providers need to be aware of these risks and take steps to mitigate them,” he said. “These findings have significant implications for patient safety. Identifying HFpEF as a risk factor can help guide clinical decisions, ensuring that patients at higher risk receive appropriate monitoring and risk reduction strategies.”
“This research underscores the importance of understanding individual risk factors.”
Tisdale’s team has already conducted a follow-up study to determine whether patients with HFpEF or HFrEF taking dofetilide or sotalol are at increased risk of life-threatening arrhythmias and sudden cardiac death. That study, “Arrhythmias in Patients with Heart Failure Prescribed Dofetilide or Sotalol,” which published in JACC: Advances, found that patients with HFrEF or HFpEF who are prescribed these medications are at an increased risk for ventricular tachycardia (VT), but not sudden cardiac arrest.
VT is a life-threatening heart rhythm disorder where the lower chambers of the heart beat rapidly and irregularly.
Tisdale is also leading studies aimed at identifying independent risk factors for QT interval prolongation in targeted patient populations and developing validated risk scores for patients who require QT-prolonging medications.
Tisdale’s collaborators included Chien-Yu Huang, a former PhD student at Purdue University; Purdue professors of pharmacy practice Brian Overholser and Kevin Sowinski; Heather Jaynes, research nurse in Purdue’s Department of Pharmacy Practice; and Richard Kovacs, Q.E. and Sally Russell Professor of Cardiology at the Indiana University School of Medicine.
