Patients with long QT syndrome, particularly long QT syndrome type 1, who were treated with antidepressants had an increased risk for recurrent cardiac arrhythmic events, according to a study published in The American Journal of Cardiology.
Meng Wang, MS, a PhD student in the department of public health sciences at the University of Rochester Medical Center in New York, and colleagues analyzed data from 59 patients with long QT syndrome type 1 (LQT1; 15% men) and 72 patients with long QT syndrome type 2 (LQT2; 36% men). Both groups had a history of treatment with antidepressant therapy and one mutant long QT syndrome gene.
The primary endpoint was cardiac arrhythmic events, which was a composite of aborted cardiac arrest, recurrent ventricular tachyarrhythmia and sudden cardiac death. These events were reviewed through self-report, physician report and implantable cardioverter defibrillator interrogations.
Enrollment and annual follow-up questionnaires were used to gather information on beta-blocker and antidepressant use, dates of start or continuation and drug name. Antidepressants were categorized based on the risk for torsades de pointes listed on the CredibleMeds website: no risk, conditional risk, possible risk and known risk.
Patients with LQT1 were followed up for a mean of 53 years, and those with LQT2 had a mean follow-up of 48 years.
Patients in the LQT1 group had 53 cardiac arrhythmic events, and 91 events occurred in the LQT2 group.
The LQT1 group had an increased risk for recurrent cardiac arrhythmic events (HR = 3.67; 95% CI, 1.98-6.82) compared with those in the LQT2 group (HR = 0.89; 95% CI, 0.49-1.64) after adjusting for sex, baseline-corrected QT duration and time-dependent beta-blocker usage (P for interaction < .001).
Patients with LQT1 who were taking antidepressants with known risk had an increased risk for recurrent events vs. those who did not take antidepressants. The risk did not differ in patients with LQT2 who took antidepressants with known risk compared with no antidepressants. The risk for recurrent events remained unchanged in patients in both groups who took antidepressants with conditional risk.
“Results from this study establish the basis for future studies to investigate the mechanisms for this [long QT syndrome] genotype-specific effect of [antidepressant drugs],” Wang and colleagues wrote. “It is important to consider genotype when prescribing [antidepressant drugs] to patients with [long QT syndrome].” – by Darlene Dobkowski
The authors report no relevant financial disclosures.